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| author | Chet Ramey <chet.ramey@case.edu> | 2011-12-12 22:36:21 -0500 |
|---|---|---|
| committer | Chet Ramey <chet.ramey@case.edu> | 2011-12-12 22:36:21 -0500 |
| commit | 8d4634252f0a1c2f1fd8cb64da2bff49c42d83fb (patch) | |
| tree | cb98541ddfda20dce347e5d8df4ebb022b400a15 /doc | |
| parent | 9519c7f69cd7dc8dbc6fc3ddc874d79dcde6a11c (diff) | |
| download | bash-8d4634252f0a1c2f1fd8cb64da2bff49c42d83fb.tar.gz | |
bash-4.2 stray file cleanup
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/b.html | 15448 |
1 files changed, 0 insertions, 15448 deletions
diff --git a/doc/b.html b/doc/b.html deleted file mode 100644 index 29b0da6b..00000000 --- a/doc/b.html +++ /dev/null @@ -1,15448 +0,0 @@ -<HTML> -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<!-- Created on January, 11 2007 by texi2html 1.64 --> -<!-- -Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author) - Karl Berry <karl@freefriends.org> - Olaf Bachmann <obachman@mathematik.uni-kl.de> - and many others. -Maintained by: Olaf Bachmann <obachman@mathematik.uni-kl.de> -Send bugs and suggestions to <texi2html@mathematik.uni-kl.de> - ---> -<HEAD> -<TITLE>Bash Reference Manual: </TITLE> - -<META NAME="description" CONTENT="Bash Reference Manual: "> -<META NAME="keywords" CONTENT="Bash Reference Manual: "> -<META NAME="resource-type" CONTENT="document"> -<META NAME="distribution" CONTENT="global"> -<META NAME="Generator" CONTENT="texi2html 1.64"> - -</HEAD> - -<BODY LANG="" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#800080" ALINK="#FF0000"> - -<A NAME="SEC_Top"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1>Bash Reference Manual</H1></P><P> - -This text is a brief description of the features that are present in -the Bash shell (version 3.2, 30 December 2006). -</P><P> - -This is Edition 3.2, last updated 30 December 2006, -of <CITE>The GNU Bash Reference Manual</CITE>, -for <CODE>Bash</CODE>, Version 3.2. -</P><P> - -Bash contains features that appear in other popular shells, and some -features that only appear in Bash. Some of the shells that Bash has -borrowed concepts from are the Bourne Shell (<TT>`sh'</TT>), the Korn Shell -(<TT>`ksh'</TT>), and the C-shell (<TT>`csh'</TT> and its successor, -<TT>`tcsh'</TT>). The following menu breaks the features up into -categories based upon which one of these other shells inspired the -feature. -</P><P> - -This manual is meant as a brief introduction to features found in -Bash. The Bash manual page should be used as the definitive -reference on shell behavior. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC1">1. Introduction</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">An introduction to the shell.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC4">2. Definitions</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Some definitions used in the rest of this - manual.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC5">3. Basic Shell Features</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The shell "building blocks".</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC56">4. Shell Builtin Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Commands that are a part of the shell.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC63">5. Shell Variables</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Variables used or set by Bash.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC66">6. Bash Features</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Features found only in Bash.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC89">7. Job Control</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What job control is and how Bash allows you - to use it.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC117">9. Using History Interactively</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Command History Expansion</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC93">8. Command Line Editing</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Chapter describing the command line - editing features.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC124">10. Installing Bash</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to build and install Bash on your system.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC133">A. Reporting Bugs</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to report bugs in Bash.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC134">B. Major Differences From The Bourne Shell</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A terse list of the differences - between Bash and historical - versions of /bin/sh.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC136">C. Copying This Manual</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Copying this manual.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC139">D. Indexes</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Various indexes for this manual.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<HR SIZE=1> -<A NAME="SEC1"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC2"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC4"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<A NAME="Introduction"></A> -<H1> 1. Introduction </H1> -<!--docid::SEC1::--> -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC2">1.1 What is Bash?</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A short description of Bash.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC3">1.2 What is a shell?</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A brief introduction to shells.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="What is Bash?"></A> -<HR SIZE="6"> -<A NAME="SEC2"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC1"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC3"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC1"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC4"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 1.1 What is Bash? </H2> -<!--docid::SEC2::--> -<P> - -Bash is the shell, or command language interpreter, -for the GNU operating system. -The name is an acronym for the <SAMP>`Bourne-Again SHell'</SAMP>, -a pun on Stephen Bourne, the author of the direct ancestor of -the current Unix shell <CODE>sh</CODE>, -which appeared in the Seventh Edition Bell Labs Research version -of Unix. -</P><P> - -Bash is largely compatible with <CODE>sh</CODE> and incorporates useful -features from the Korn shell <CODE>ksh</CODE> and the C shell <CODE>csh</CODE>. -It is intended to be a conformant implementation of the IEEE -POSIX Shell and Tools portion of the IEEE POSIX -specification (IEEE Standard 1003.1). -It offers functional improvements over <CODE>sh</CODE> for both interactive and -programming use. -</P><P> - -While the GNU operating system provides other shells, including -a version of <CODE>csh</CODE>, Bash is the default shell. -Like other GNU software, Bash is quite portable. It currently runs -on nearly every version of Unix and a few other operating systems - -independently-supported ports exist for MS-DOS, OS/2, -and Windows platforms. -</P><P> - -<A NAME="What is a shell?"></A> -<HR SIZE="6"> -<A NAME="SEC3"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC2"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC4"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC1"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC4"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 1.2 What is a shell? </H2> -<!--docid::SEC3::--> -<P> - -At its base, a shell is simply a macro processor that executes -commands. The term macro processor means functionality where text -and symbols are expanded to create larger expressions. -</P><P> - -A Unix shell is both a command interpreter and a programming -language. As a command interpreter, the shell provides the user -interface to the rich set of GNU utilities. The programming -language features allow these utilities to be combined. -Files containing commands can be created, and become -commands themselves. These new commands have the same status as -system commands in directories such as <TT>`/bin'</TT>, allowing users -or groups to establish custom environments to automate their common -tasks. -</P><P> - -Shells may be used interactively or non-interactively. In -interactive mode, they accept input typed from the keyboard. -When executing non-interactively, shells execute commands read -from a file. -</P><P> - -A shell allows execution of GNU commands, both synchronously and -asynchronously. -The shell waits for synchronous commands to complete before accepting -more input; asynchronous commands continue to execute in parallel -with the shell while it reads and executes additional commands. -The <EM>redirection</EM> constructs permit -fine-grained control of the input and output of those commands. -Moreover, the shell allows control over the contents of commands' -environments. -</P><P> - -Shells also provide a small set of built-in -commands (<EM>builtins</EM>) implementing functionality impossible -or inconvenient to obtain via separate utilities. -For example, <CODE>cd</CODE>, <CODE>break</CODE>, <CODE>continue</CODE>, and -<CODE>exec</CODE>) cannot be implemented outside of the shell because -they directly manipulate the shell itself. -The <CODE>history</CODE>, <CODE>getopts</CODE>, <CODE>kill</CODE>, or <CODE>pwd</CODE> -builtins, among others, could be implemented in separate utilities, -but they are more convenient to use as builtin commands. -All of the shell builtins are described in -subsequent sections. -</P><P> - -While executing commands is essential, most of the power (and -complexity) of shells is due to their embedded programming -languages. Like any high-level language, the shell provides -variables, flow control constructs, quoting, and functions. -</P><P> - -Shells offer features geared specifically for -interactive use rather than to augment the programming language. -These interactive features include job control, command line -editing, command history and aliases. Each of these features is -described in this manual. -</P><P> - -<A NAME="Definitions"></A> -<HR SIZE="6"> -<A NAME="SEC4"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC3"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 2. Definitions </H1> -<!--docid::SEC4::--> -These definitions are used throughout the remainder of this manual. -<P> - -<DL COMPACT> - -<DT><CODE>POSIX</CODE> -<DD><A NAME="IDX1"></A> -A family of open system standards based on Unix. Bash -is primarily concerned with the Shell and Utilities portion of the -POSIX 1003.1 standard. -<P> - -<DT><CODE>blank</CODE> -<DD>A space or tab character. -<P> - -<DT><CODE>builtin</CODE> -<DD><A NAME="IDX2"></A> -A command that is implemented internally by the shell itself, rather -than by an executable program somewhere in the file system. -<P> - -<DT><CODE>control operator</CODE> -<DD><A NAME="IDX3"></A> -A <CODE>word</CODE> that performs a control function. It is a <CODE>newline</CODE> -or one of the following: -<SAMP>`||'</SAMP>, <SAMP>`&&'</SAMP>, <SAMP>`&'</SAMP>, <SAMP>`;'</SAMP>, <SAMP>`;;'</SAMP>, -<SAMP>`|'</SAMP>, <SAMP>`('</SAMP>, or <SAMP>`)'</SAMP>. -<P> - -<DT><CODE>exit status</CODE> -<DD><A NAME="IDX4"></A> -The value returned by a command to its caller. The value is restricted -to eight bits, so the maximum value is 255. -<P> - -<DT><CODE>field</CODE> -<DD><A NAME="IDX5"></A> -A unit of text that is the result of one of the shell expansions. After -expansion, when executing a command, the resulting fields are used as -the command name and arguments. -<P> - -<DT><CODE>filename</CODE> -<DD><A NAME="IDX6"></A> -A string of characters used to identify a file. -<P> - -<DT><CODE>job</CODE> -<DD><A NAME="IDX7"></A> -A set of processes comprising a pipeline, and any processes descended -from it, that are all in the same process group. -<P> - -<DT><CODE>job control</CODE> -<DD><A NAME="IDX8"></A> -A mechanism by which users can selectively stop (suspend) and restart -(resume) execution of processes. -<P> - -<DT><CODE>metacharacter</CODE> -<DD><A NAME="IDX9"></A> -A character that, when unquoted, separates words. A metacharacter is -a <CODE>blank</CODE> or one of the following characters: -<SAMP>`|'</SAMP>, <SAMP>`&'</SAMP>, <SAMP>`;'</SAMP>, <SAMP>`('</SAMP>, <SAMP>`)'</SAMP>, <SAMP>`<'</SAMP>, or -<SAMP>`>'</SAMP>. -<P> - -<DT><CODE>name</CODE> -<DD><A NAME="IDX10"></A> -<A NAME="IDX11"></A> -A <CODE>word</CODE> consisting solely of letters, numbers, and underscores, -and beginning with a letter or underscore. <CODE>Name</CODE>s are used as -shell variable and function names. -Also referred to as an <CODE>identifier</CODE>. -<P> - -<DT><CODE>operator</CODE> -<DD><A NAME="IDX12"></A> -A <CODE>control operator</CODE> or a <CODE>redirection operator</CODE>. -See section <A HREF="b.html#SEC38">3.6 Redirections</A>, for a list of redirection operators. -<P> - -<DT><CODE>process group</CODE> -<DD><A NAME="IDX13"></A> -A collection of related processes each having the same process -group ID. -<P> - -<DT><CODE>process group ID</CODE> -<DD><A NAME="IDX14"></A> -A unique identifier that represents a <CODE>process group</CODE> -during its lifetime. -<P> - -<DT><CODE>reserved word</CODE> -<DD><A NAME="IDX15"></A> -A <CODE>word</CODE> that has a special meaning to the shell. Most reserved -words introduce shell flow control constructs, such as <CODE>for</CODE> and -<CODE>while</CODE>. -<P> - -<DT><CODE>return status</CODE> -<DD><A NAME="IDX16"></A> -A synonym for <CODE>exit status</CODE>. -<P> - -<DT><CODE>signal</CODE> -<DD><A NAME="IDX17"></A> -A mechanism by which a process may be notified by the kernel -of an event occurring in the system. -<P> - -<DT><CODE>special builtin</CODE> -<DD><A NAME="IDX18"></A> -A shell builtin command that has been classified as special by the -POSIX standard. -<P> - -<DT><CODE>token</CODE> -<DD><A NAME="IDX19"></A> -A sequence of characters considered a single unit by the shell. It is -either a <CODE>word</CODE> or an <CODE>operator</CODE>. -<P> - -<DT><CODE>word</CODE> -<DD><A NAME="IDX20"></A> -A <CODE>token</CODE> that is not an <CODE>operator</CODE>. -</DL> -<P> - -<A NAME="Basic Shell Features"></A> -<HR SIZE="6"> -<A NAME="SEC5"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC4"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC6"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 3. Basic Shell Features </H1> -<!--docid::SEC5::--> -<P> - -Bash is an acronym for <SAMP>`Bourne-Again SHell'</SAMP>. -The Bourne shell is -the traditional Unix shell originally written by Stephen Bourne. -All of the Bourne shell builtin commands are available in Bash, -The rules for evaluation and quoting are taken from the POSIX -specification for the `standard' Unix shell. -</P><P> - -This chapter briefly summarizes the shell's `building blocks': -commands, control structures, shell functions, shell <I>parameters</I>, -shell expansions, -<I>redirections</I>, which are a way to direct input and output from -and to named files, and how the shell executes commands. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC6">3.1 Shell Syntax</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What your input means to the shell.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC15">3.2 Shell Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The types of commands you can use.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC23">3.3 Shell Functions</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Grouping commands by name.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC24">3.4 Shell Parameters</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How the shell stores values.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC27">3.5 Shell Expansions</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How Bash expands parameters and the various - expansions available.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC38">3.6 Redirections</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A way to control where input and output go.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC48">3.7 Executing Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What happens when you run a command.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC55">3.8 Shell Scripts</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Executing files of shell commands.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Shell Syntax"></A> -<HR SIZE="6"> -<A NAME="SEC6"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC7"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.1 Shell Syntax </H2> -<!--docid::SEC6::--> -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC7">3.1.1 Shell Operation</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The basic operation of the shell.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC8">3.1.2 Quoting</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to remove the special meaning from characters.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC14">3.1.3 Comments</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to specify comments.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -When the shell reads input, it proceeds through a -sequence of operations. If the input indicates the beginning of a -comment, the shell ignores the comment symbol (<SAMP>`#'</SAMP>), and the rest -of that line. - -Otherwise, roughly speaking, the shell reads its input and -divides the input into words and operators, employing the quoting rules -to select which meanings to assign various words and characters. -</P><P> - -The shell then parses these tokens into commands and other constructs, -removes the special meaning of certain words or characters, expands -others, redirects input and output as needed, executes the specified -command, waits for the command's exit status, and makes that exit status -available for further inspection or processing. -</P><P> - -<A NAME="Shell Operation"></A> -<HR SIZE="6"> -<A NAME="SEC7"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC6"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC8"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC6"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.1.1 Shell Operation </H3> -<!--docid::SEC7::--> -<P> - -The following is a brief description of the shell's operation when it -reads and executes a command. Basically, the shell does the -following: -</P><P> - -<OL> -<LI> -Reads its input from a file (see section <A HREF="b.html#SEC55">3.8 Shell Scripts</A>), from a string -supplied as an argument to the <SAMP>`-c'</SAMP> invocation option -(see section <A HREF="b.html#SEC67">6.1 Invoking Bash</A>), or from the user's terminal. -<P> - -<LI> -Breaks the input into words and operators, obeying the quoting rules -described in <A HREF="b.html#SEC8">3.1.2 Quoting</A>. These tokens are separated by -<CODE>metacharacters</CODE>. Alias expansion is performed by this step -(see section <A HREF="b.html#SEC82">6.6 Aliases</A>). -<P> - -<LI> -Parses the tokens into simple and compound commands -(see section <A HREF="b.html#SEC15">3.2 Shell Commands</A>). -<P> - -<LI> -Performs the various shell expansions (see section <A HREF="b.html#SEC27">3.5 Shell Expansions</A>), breaking -the expanded tokens into lists of filenames (see section <A HREF="b.html#SEC35">3.5.8 Filename Expansion</A>) -and commands and arguments. -<P> - -<LI> -Performs any necessary redirections (see section <A HREF="b.html#SEC38">3.6 Redirections</A>) and removes -the redirection operators and their operands from the argument list. -<P> - -<LI> -Executes the command (see section <A HREF="b.html#SEC48">3.7 Executing Commands</A>). -<P> - -<LI> -Optionally waits for the command to complete and collects its exit -status (see section <A HREF="b.html#SEC53">3.7.5 Exit Status</A>). -<P> - -</OL> -<P> - -<A NAME="Quoting"></A> -<HR SIZE="6"> -<A NAME="SEC8"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC7"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC9"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC6"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.1.2 Quoting </H3> -<!--docid::SEC8::--> -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC9">3.1.2.1 Escape Character</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to remove the special meaning from a single - character.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC10">3.1.2.2 Single Quotes</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to inhibit all interpretation of a sequence - of characters.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC11">3.1.2.3 Double Quotes</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to suppress most of the interpretation of a - sequence of characters.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC12">3.1.2.4 ANSI-C Quoting</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to expand ANSI-C sequences in quoted strings.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to translate strings into different languages.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -Quoting is used to remove the special meaning of certain -characters or words to the shell. Quoting can be used to -disable special treatment for special characters, to prevent -reserved words from being recognized as such, and to prevent -parameter expansion. -</P><P> - -Each of the shell metacharacters (see section <A HREF="b.html#SEC4">2. Definitions</A>) -has special meaning to the shell and must be quoted if it is to -represent itself. -When the command history expansion facilities are being used -(see section <A HREF="b.html#SEC120">9.3 History Expansion</A>), the -<VAR>history expansion</VAR> character, usually <SAMP>`!'</SAMP>, must be quoted -to prevent history expansion. See section <A HREF="b.html#SEC118">9.1 Bash History Facilities</A>, for -more details concerning history expansion. -</P><P> - -There are three quoting mechanisms: the -<VAR>escape character</VAR>, single quotes, and double quotes. -</P><P> - -<A NAME="Escape Character"></A> -<HR SIZE="6"> -<A NAME="SEC9"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC8"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC10"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC8"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.1.2.1 Escape Character </H4> -<!--docid::SEC9::--> -A non-quoted backslash <SAMP>`\'</SAMP> is the Bash escape character. -It preserves the literal value of the next character that follows, -with the exception of <CODE>newline</CODE>. If a <CODE>\newline</CODE> pair -appears, and the backslash itself is not quoted, the <CODE>\newline</CODE> -is treated as a line continuation (that is, it is removed from -the input stream and effectively ignored). -<P> - -<A NAME="Single Quotes"></A> -<HR SIZE="6"> -<A NAME="SEC10"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC9"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC11"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC11"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC8"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.1.2.2 Single Quotes </H4> -<!--docid::SEC10::--> -<P> - -Enclosing characters in single quotes (<SAMP>`''</SAMP>) preserves the literal value -of each character within the quotes. A single quote may not occur -between single quotes, even when preceded by a backslash. -</P><P> - -<A NAME="Double Quotes"></A> -<HR SIZE="6"> -<A NAME="SEC11"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC10"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC12"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC12"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC8"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.1.2.3 Double Quotes </H4> -<!--docid::SEC11::--> -<P> - -Enclosing characters in double quotes (<SAMP>`"'</SAMP>) preserves the literal value -of all characters within the quotes, with the exception of -<SAMP>`$'</SAMP>, <SAMP>``'</SAMP>, <SAMP>`\'</SAMP>, -and, when history expansion is enabled, <SAMP>`!'</SAMP>. -The characters <SAMP>`$'</SAMP> and <SAMP>``'</SAMP> -retain their special meaning within double quotes (see section <A HREF="b.html#SEC27">3.5 Shell Expansions</A>). -The backslash retains its special meaning only when followed by one of -the following characters: -<SAMP>`$'</SAMP>, <SAMP>``'</SAMP>, <SAMP>`"'</SAMP>, <SAMP>`\'</SAMP>, or <CODE>newline</CODE>. -Within double quotes, backslashes that are followed by one of these -characters are removed. Backslashes preceding characters without a -special meaning are left unmodified. -A double quote may be quoted within double quotes by preceding it with -a backslash. -If enabled, history expansion will be performed unless an <SAMP>`!'</SAMP> -appearing in double quotes is escaped using a backslash. -The backslash preceding the <SAMP>`!'</SAMP> is not removed. -</P><P> - -The special parameters <SAMP>`*'</SAMP> and <SAMP>`@'</SAMP> have special meaning -when in double quotes (see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -</P><P> - -<A NAME="ANSI-C Quoting"></A> -<HR SIZE="6"> -<A NAME="SEC12"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC11"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC13"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC13"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC8"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.1.2.4 ANSI-C Quoting </H4> -<!--docid::SEC12::--> -<P> - -Words of the form <CODE>$'<VAR>string</VAR>'</CODE> are treated specially. The -word expands to <VAR>string</VAR>, with backslash-escaped characters replaced -as specified by the ANSI C standard. Backslash escape sequences, if -present, are decoded as follows: -</P><P> - -<DL COMPACT> -<DT><CODE>\a</CODE> -<DD>alert (bell) -<DT><CODE>\b</CODE> -<DD>backspace -<DT><CODE>\e</CODE> -<DD>an escape character (not ANSI C) -<DT><CODE>\f</CODE> -<DD>form feed -<DT><CODE>\n</CODE> -<DD>newline -<DT><CODE>\r</CODE> -<DD>carriage return -<DT><CODE>\t</CODE> -<DD>horizontal tab -<DT><CODE>\v</CODE> -<DD>vertical tab -<DT><CODE>\\</CODE> -<DD>backslash -<DT><CODE>\'</CODE> -<DD>single quote -<DT><CODE>\<VAR>nnn</VAR></CODE> -<DD>the eight-bit character whose value is the octal value <VAR>nnn</VAR> -(one to three digits) -<DT><CODE>\x<VAR>HH</VAR></CODE> -<DD>the eight-bit character whose value is the hexadecimal value <VAR>HH</VAR> -(one or two hex digits) -<DT><CODE>\c<VAR>x</VAR></CODE> -<DD>a control-<VAR>x</VAR> character -</DL> -<P> - -The expanded result is single-quoted, as if the dollar sign had not -been present. -</P><P> - -<A NAME="Locale Translation"></A> -<HR SIZE="6"> -<A NAME="SEC13"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC12"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC8"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.1.2.5 Locale-Specific Translation </H4> -<!--docid::SEC13::--> -<P> - -A double-quoted string preceded by a dollar sign (<SAMP>`$'</SAMP>) will cause -the string to be translated according to the current locale. -If the current locale is <CODE>C</CODE> or <CODE>POSIX</CODE>, the dollar sign -is ignored. -If the string is translated and replaced, the replacement is -double-quoted. -</P><P> - -<A NAME="IDX21"></A> -<A NAME="IDX22"></A> -<A NAME="IDX23"></A> -Some systems use the message catalog selected by the <CODE>LC_MESSAGES</CODE> -shell variable. Others create the name of the message catalog from the -value of the <CODE>TEXTDOMAIN</CODE> shell variable, possibly adding a -suffix of <SAMP>`.mo'</SAMP>. If you use the <CODE>TEXTDOMAIN</CODE> variable, you -may need to set the <CODE>TEXTDOMAINDIR</CODE> variable to the location of -the message catalog files. Still others use both variables in this -fashion: -<CODE>TEXTDOMAINDIR</CODE>/<CODE>LC_MESSAGES</CODE>/LC_MESSAGES/<CODE>TEXTDOMAIN</CODE>.mo. -</P><P> - -<A NAME="Comments"></A> -<HR SIZE="6"> -<A NAME="SEC14"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC13"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC6"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.1.3 Comments </H3> -<!--docid::SEC14::--> -<P> - -In a non-interactive shell, or an interactive shell in which the -<CODE>interactive_comments</CODE> option to the <CODE>shopt</CODE> -builtin is enabled (see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>), -a word beginning with <SAMP>`#'</SAMP> -causes that word and all remaining characters on that line to -be ignored. An interactive shell without the <CODE>interactive_comments</CODE> -option enabled does not allow comments. The <CODE>interactive_comments</CODE> -option is on by default in interactive shells. -See section <A HREF="b.html#SEC76">6.3 Interactive Shells</A>, for a description of what makes -a shell interactive. -</P><P> - -<A NAME="Shell Commands"></A> -<HR SIZE="6"> -<A NAME="SEC15"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC14"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC16"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.2 Shell Commands </H2> -<!--docid::SEC15::--> -<P> - -A simple shell command such as <CODE>echo a b c</CODE> consists of the command -itself followed by arguments, separated by spaces. -</P><P> - -More complex shell commands are composed of simple commands arranged together -in a variety of ways: in a pipeline in which the output of one command -becomes the input of a second, in a loop or conditional construct, or in -some other grouping. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC16">3.2.1 Simple Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The most common type of command.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC17">3.2.2 Pipelines</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Connecting the input and output of several - commands.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC18">3.2.3 Lists of Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to execute commands sequentially.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC19">3.2.4 Compound Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Shell commands for control flow.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Simple Commands"></A> -<HR SIZE="6"> -<A NAME="SEC16"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC17"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.2.1 Simple Commands </H3> -<!--docid::SEC16::--> -<P> - -A simple command is the kind of command encountered most often. -It's just a sequence of words separated by <CODE>blank</CODE>s, terminated -by one of the shell's control operators (see section <A HREF="b.html#SEC4">2. Definitions</A>). The -first word generally specifies a command to be executed, with the -rest of the words being that command's arguments. -</P><P> - -The return status (see section <A HREF="b.html#SEC53">3.7.5 Exit Status</A>) of a simple command is -its exit status as provided -by the POSIX 1003.1 <CODE>waitpid</CODE> function, or 128+<VAR>n</VAR> if -the command was terminated by signal <VAR>n</VAR>. -</P><P> - -<A NAME="Pipelines"></A> -<HR SIZE="6"> -<A NAME="SEC17"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC16"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC18"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC18"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.2.2 Pipelines </H3> -<!--docid::SEC17::--> -<P> - -A <CODE>pipeline</CODE> is a sequence of simple commands separated by -<SAMP>`|'</SAMP>. -</P><P> - -<A NAME="IDX24"></A> -<A NAME="IDX25"></A> -<A NAME="IDX26"></A> -The format for a pipeline is -<TABLE><tr><td> </td><td class=example><pre>[<CODE>time</CODE> [<CODE>-p</CODE>]] [<CODE>!</CODE>] <VAR>command1</VAR> [<CODE>|</CODE> <VAR>command2</VAR> <small>...</small>] -</pre></td></tr></table></P><P> - -The output of each command in the pipeline is connected via a pipe -to the input of the next command. -That is, each command reads the previous command's output. -</P><P> - -The reserved word <CODE>time</CODE> causes timing statistics -to be printed for the pipeline once it finishes. -The statistics currently consist of elapsed (wall-clock) time and -user and system time consumed by the command's execution. -The <SAMP>`-p'</SAMP> option changes the output format to that specified -by POSIX. -The <CODE>TIMEFORMAT</CODE> variable may be set to a format string that -specifies how the timing information should be displayed. -See section <A HREF="b.html#SEC65">5.2 Bash Variables</A>, for a description of the available formats. -The use of <CODE>time</CODE> as a reserved word permits the timing of -shell builtins, shell functions, and pipelines. An external -<CODE>time</CODE> command cannot time these easily. -</P><P> - -If the pipeline is not executed asynchronously (see section <A HREF="b.html#SEC18">3.2.3 Lists of Commands</A>), the -shell waits for all commands in the pipeline to complete. -</P><P> - -Each command in a pipeline is executed in its own subshell -(see section <A HREF="b.html#SEC51">3.7.3 Command Execution Environment</A>). The exit -status of a pipeline is the exit status of the last command in the -pipeline, unless the <CODE>pipefail</CODE> option is enabled -(see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -If <CODE>pipefail</CODE> is enabled, the pipeline's return status is the -value of the last (rightmost) command to exit with a non-zero status, -or zero if all commands exit successfully. -If the reserved word <SAMP>`!'</SAMP> precedes the pipeline, the -exit status is the logical negation of the exit status as described -above. -The shell waits for all commands in the pipeline to terminate before -returning a value. -</P><P> - -<A NAME="Lists"></A> -<HR SIZE="6"> -<A NAME="SEC18"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC17"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC19"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC19"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.2.3 Lists of Commands </H3> -<!--docid::SEC18::--> -<P> - -A <CODE>list</CODE> is a sequence of one or more pipelines separated by one -of the operators <SAMP>`;'</SAMP>, <SAMP>`&'</SAMP>, <SAMP>`&&'</SAMP>, or <SAMP>`||'</SAMP>, -and optionally terminated by one of <SAMP>`;'</SAMP>, <SAMP>`&'</SAMP>, or a -<CODE>newline</CODE>. -</P><P> - -Of these list operators, <SAMP>`&&'</SAMP> and <SAMP>`||'</SAMP> -have equal precedence, followed by <SAMP>`;'</SAMP> and <SAMP>`&'</SAMP>, -which have equal precedence. -</P><P> - -A sequence of one or more newlines may appear in a <CODE>list</CODE> -to delimit commands, equivalent to a semicolon. -</P><P> - -If a command is terminated by the control operator <SAMP>`&'</SAMP>, -the shell executes the command asynchronously in a subshell. -This is known as executing the command in the <VAR>background</VAR>. -The shell does not wait for the command to finish, and the return -status is 0 (true). -When job control is not active (see section <A HREF="b.html#SEC89">7. Job Control</A>), -the standard input for asynchronous commands, in the absence of any -explicit redirections, is redirected from <CODE>/dev/null</CODE>. -</P><P> - -Commands separated by a <SAMP>`;'</SAMP> are executed sequentially; the shell -waits for each command to terminate in turn. The return status is the -exit status of the last command executed. -</P><P> - -The control operators <SAMP>`&&'</SAMP> and <SAMP>`||'</SAMP> -denote AND lists and OR lists, respectively. -An AND list has the form -<TABLE><tr><td> </td><td class=example><pre><VAR>command1</VAR> && <VAR>command2</VAR> -</pre></td></tr></table></P><P> - -<VAR>command2</VAR> is executed if, and only if, <VAR>command1</VAR> -returns an exit status of zero. -</P><P> - -An OR list has the form -<TABLE><tr><td> </td><td class=example><pre><VAR>command1</VAR> || <VAR>command2</VAR> -</pre></td></tr></table></P><P> - -<VAR>command2</VAR> is executed if, and only if, <VAR>command1</VAR> -returns a non-zero exit status. -</P><P> - -The return status of -AND and OR lists is the exit status of the last command -executed in the list. -</P><P> - -<A NAME="Compound Commands"></A> -<HR SIZE="6"> -<A NAME="SEC19"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC18"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC20"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC15"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.2.4 Compound Commands </H3> -<!--docid::SEC19::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Shell commands for iterative action.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Shell commands for conditional execution.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC22">3.2.4.3 Grouping Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Ways to group commands.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -Compound commands are the shell programming constructs. -Each construct begins with a reserved word or control operator and is -terminated by a corresponding reserved word or operator. -Any redirections (see section <A HREF="b.html#SEC38">3.6 Redirections</A>) associated with a compound command -apply to all commands within that compound command unless explicitly overridden. -</P><P> - -Bash provides looping constructs, conditional commands, and mechanisms -to group commands and execute them as a unit. -</P><P> - -<A NAME="Looping Constructs"></A> -<HR SIZE="6"> -<A NAME="SEC20"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC19"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC21"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC19"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.2.4.1 Looping Constructs </H4> -<!--docid::SEC20::--> -<P> - -Bash supports the following looping constructs. -</P><P> - -Note that wherever a <SAMP>`;'</SAMP> appears in the description of a -command's syntax, it may be replaced with one or more newlines. -</P><P> - -<DL COMPACT> -<DT><CODE>until</CODE> -<DD><A NAME="IDX27"></A> -<A NAME="IDX28"></A> -<A NAME="IDX29"></A> -The syntax of the <CODE>until</CODE> command is: -<TABLE><tr><td> </td><td class=example><pre>until <VAR>test-commands</VAR>; do <VAR>consequent-commands</VAR>; done -</pre></td></tr></table>Execute <VAR>consequent-commands</VAR> as long as -<VAR>test-commands</VAR> has an exit status which is not zero. -The return status is the exit status of the last command executed -in <VAR>consequent-commands</VAR>, or zero if none was executed. -<P> - -<DT><CODE>while</CODE> -<DD><A NAME="IDX30"></A> -The syntax of the <CODE>while</CODE> command is: -<TABLE><tr><td> </td><td class=example><pre>while <VAR>test-commands</VAR>; do <VAR>consequent-commands</VAR>; done -</pre></td></tr></table><P> - -Execute <VAR>consequent-commands</VAR> as long as -<VAR>test-commands</VAR> has an exit status of zero. -The return status is the exit status of the last command executed -in <VAR>consequent-commands</VAR>, or zero if none was executed. -</P><P> - -<DT><CODE>for</CODE> -<DD><A NAME="IDX31"></A> -The syntax of the <CODE>for</CODE> command is: -<P> - -<TABLE><tr><td> </td><td class=example><pre>for <VAR>name</VAR> [in <VAR>words</VAR> <small>...</small>]; do <VAR>commands</VAR>; done -</pre></td></tr></table>Expand <VAR>words</VAR>, and execute <VAR>commands</VAR> once for each member -in the resultant list, with <VAR>name</VAR> bound to the current member. -If <SAMP>`in <VAR>words</VAR>'</SAMP> is not present, the <CODE>for</CODE> command -executes the <VAR>commands</VAR> once for each positional parameter that is -set, as if <SAMP>`in "$@"'</SAMP> had been specified -(see section <A HREF="b.html#SEC26">3.4.2 Special Parameters</A>). -The return status is the exit status of the last command that executes. -If there are no items in the expansion of <VAR>words</VAR>, no commands are -executed, and the return status is zero. -</P><P> - -An alternate form of the <CODE>for</CODE> command is also supported: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>for (( <VAR>expr1</VAR> ; <VAR>expr2</VAR> ; <VAR>expr3</VAR> )) ; do <VAR>commands</VAR> ; done -</pre></td></tr></table>First, the arithmetic expression <VAR>expr1</VAR> is evaluated according -to the rules described below (see section <A HREF="b.html#SEC81">6.5 Shell Arithmetic</A>). -The arithmetic expression <VAR>expr2</VAR> is then evaluated repeatedly -until it evaluates to zero. -Each time <VAR>expr2</VAR> evaluates to a non-zero value, <VAR>commands</VAR> are -executed and the arithmetic expression <VAR>expr3</VAR> is evaluated. -If any expression is omitted, it behaves as if it evaluates to 1. -The return value is the exit status of the last command in <VAR>list</VAR> -that is executed, or false if any of the expressions is invalid. -</P><P> - -</DL> -<P> - -The <CODE>break</CODE> and <CODE>continue</CODE> builtins (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>) -may be used to control loop execution. -</P><P> - -<A NAME="Conditional Constructs"></A> -<HR SIZE="6"> -<A NAME="SEC21"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC20"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC22"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC22"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC19"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.2.4.2 Conditional Constructs </H4> -<!--docid::SEC21::--> -<P> - -<DL COMPACT> -<DT><CODE>if</CODE> -<DD><A NAME="IDX32"></A> -<A NAME="IDX33"></A> -<A NAME="IDX34"></A> -<A NAME="IDX35"></A> -<A NAME="IDX36"></A> -The syntax of the <CODE>if</CODE> command is: -<P> - -<TABLE><tr><td> </td><td class=example><pre>if <VAR>test-commands</VAR>; then - <VAR>consequent-commands</VAR>; -[elif <VAR>more-test-commands</VAR>; then - <VAR>more-consequents</VAR>;] -[else <VAR>alternate-consequents</VAR>;] -fi -</pre></td></tr></table></P><P> - -The <VAR>test-commands</VAR> list is executed, and if its return status is zero, -the <VAR>consequent-commands</VAR> list is executed. -If <VAR>test-commands</VAR> returns a non-zero status, each <CODE>elif</CODE> list -is executed in turn, and if its exit status is zero, -the corresponding <VAR>more-consequents</VAR> is executed and the -command completes. -If <SAMP>`else <VAR>alternate-consequents</VAR>'</SAMP> is present, and -the final command in the final <CODE>if</CODE> or <CODE>elif</CODE> clause -has a non-zero exit status, then <VAR>alternate-consequents</VAR> is executed. -The return status is the exit status of the last command executed, or -zero if no condition tested true. -</P><P> - -<DT><CODE>case</CODE> -<DD><A NAME="IDX37"></A> -<A NAME="IDX38"></A> -<A NAME="IDX39"></A> -The syntax of the <CODE>case</CODE> command is: -<P> - -<TABLE><tr><td> </td><td class=example><pre><CODE>case <VAR>word</VAR> in [ [(] <VAR>pattern</VAR> [| <VAR>pattern</VAR>]<small>...</small>) <VAR>command-list</VAR> ;;]<small>...</small> esac</CODE> -</pre></td></tr></table></P><P> - -<CODE>case</CODE> will selectively execute the <VAR>command-list</VAR> corresponding to -the first <VAR>pattern</VAR> that matches <VAR>word</VAR>. -If the shell option <CODE>nocasematch</CODE> -(see the description of <CODE>shopt</CODE> in <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>) -is enabled, the match is performed without regard to the case -of alphabetic characters. -The <SAMP>`|'</SAMP> is used to separate multiple patterns, and the <SAMP>`)'</SAMP> -operator terminates a pattern list. -A list of patterns and an associated command-list is known -as a <VAR>clause</VAR>. Each clause must be terminated with <SAMP>`;;'</SAMP>. -The <VAR>word</VAR> undergoes tilde expansion, parameter expansion, command -substitution, arithmetic expansion, and quote removal before matching is -attempted. Each <VAR>pattern</VAR> undergoes tilde expansion, parameter -expansion, command substitution, and arithmetic expansion. -</P><P> - -There may be an arbitrary number of <CODE>case</CODE> clauses, each terminated -by a <SAMP>`;;'</SAMP>. The first pattern that matches determines the -command-list that is executed. -</P><P> - -Here is an example using <CODE>case</CODE> in a script that could be used to -describe one interesting feature of an animal: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>echo -n "Enter the name of an animal: " -read ANIMAL -echo -n "The $ANIMAL has " -case $ANIMAL in - horse | dog | cat) echo -n "four";; - man | kangaroo ) echo -n "two";; - *) echo -n "an unknown number of";; -esac -echo " legs." -</pre></td></tr></table></P><P> - -The return status is zero if no <VAR>pattern</VAR> is matched. Otherwise, the -return status is the exit status of the <VAR>command-list</VAR> executed. -</P><P> - -<DT><CODE>select</CODE> -<DD><A NAME="IDX40"></A> -<P> - -The <CODE>select</CODE> construct allows the easy generation of menus. -It has almost the same syntax as the <CODE>for</CODE> command: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>select <VAR>name</VAR> [in <VAR>words</VAR> <small>...</small>]; do <VAR>commands</VAR>; done -</pre></td></tr></table></P><P> - -The list of words following <CODE>in</CODE> is expanded, generating a list -of items. The set of expanded words is printed on the standard -error output stream, each preceded by a number. If the -<SAMP>`in <VAR>words</VAR>'</SAMP> is omitted, the positional parameters are printed, -as if <SAMP>`in "$@"'</SAMP> had been specified. -The <CODE>PS3</CODE> prompt is then displayed and a line is read from the -standard input. -If the line consists of a number corresponding to one of the displayed -words, then the value of <VAR>name</VAR> is set to that word. -If the line is empty, the words and prompt are displayed again. -If <CODE>EOF</CODE> is read, the <CODE>select</CODE> command completes. -Any other value read causes <VAR>name</VAR> to be set to null. -The line read is saved in the variable <CODE>REPLY</CODE>. -</P><P> - -The <VAR>commands</VAR> are executed after each selection until a -<CODE>break</CODE> command is executed, at which -point the <CODE>select</CODE> command completes. -</P><P> - -Here is an example that allows the user to pick a filename from the -current directory, and displays the name and index of the file -selected. -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>select fname in *; -do - echo you picked $fname \($REPLY\) - break; -done -</pre></td></tr></table></P><P> - -<DT><CODE>((<small>...</small>))</CODE> -<DD><TABLE><tr><td> </td><td class=example><pre>(( <VAR>expression</VAR> )) -</pre></td></tr></table><P> - -The arithmetic <VAR>expression</VAR> is evaluated according to the rules -described below (see section <A HREF="b.html#SEC81">6.5 Shell Arithmetic</A>). -If the value of the expression is non-zero, the return status is 0; -otherwise the return status is 1. This is exactly equivalent to -<TABLE><tr><td> </td><td class=example><pre>let "<VAR>expression</VAR>" -</pre></td></tr></table>See section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>, for a full description of the <CODE>let</CODE> builtin. -</P><P> - -<DT><CODE>[[<small>...</small>]]</CODE> -<DD><A NAME="IDX41"></A> -<A NAME="IDX42"></A> -<TABLE><tr><td> </td><td class=example><pre>[[ <VAR>expression</VAR> ]] -</pre></td></tr></table><P> - -Return a status of 0 or 1 depending on the evaluation of -the conditional expression <VAR>expression</VAR>. -Expressions are composed of the primaries described below in -<A HREF="b.html#SEC80">6.4 Bash Conditional Expressions</A>. -Word splitting and filename expansion are not performed on the words -between the <SAMP>`[['</SAMP> and <SAMP>`]]'</SAMP>; tilde expansion, parameter and -variable expansion, arithmetic expansion, command substitution, process -substitution, and quote removal are performed. -Conditional operators such as <SAMP>`-f'</SAMP> must be unquoted to be recognized -as primaries. -</P><P> - -When the <SAMP>`=='</SAMP> and <SAMP>`!='</SAMP> operators are used, the string to the -right of the operator is considered a pattern and matched according -to the rules described below in <A HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A>. -If the shell option <CODE>nocasematch</CODE> -(see the description of <CODE>shopt</CODE> in <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>) -is enabled, the match is performed without regard to the case -of alphabetic characters. -The return value is 0 if the string matches (<SAMP>`=='</SAMP>) or does not -match (<SAMP>`!='</SAMP>)the pattern, and 1 otherwise. -Any part of the pattern may be quoted to force it to be matched as a -string. -</P><P> - -An additional binary operator, <SAMP>`=~'</SAMP>, is available, with the same -precedence as <SAMP>`=='</SAMP> and <SAMP>`!='</SAMP>. -When it is used, the string to the right of the operator is considered -an extended regular expression and matched accordingly (as in <I>regex</I>3)). -The return value is 0 if the string matches -the pattern, and 1 otherwise. -If the regular expression is syntactically incorrect, the conditional -expression's return value is 2. -If the shell option <CODE>nocasematch</CODE> -(see the description of <CODE>shopt</CODE> in <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>) -is enabled, the match is performed without regard to the case -of alphabetic characters. -Substrings matched by parenthesized subexpressions within the regular -expression are saved in the array variable <CODE>BASH_REMATCH</CODE>. -The element of <CODE>BASH_REMATCH</CODE> with index 0 is the portion of the string -matching the entire regular expression. -The element of <CODE>BASH_REMATCH</CODE> with index <VAR>n</VAR> is the portion of the -string matching the <VAR>n</VAR>th parenthesized subexpression. -</P><P> - -Expressions may be combined using the following operators, listed -in decreasing order of precedence: -</P><P> - -<DL COMPACT> -<DT><CODE>( <VAR>expression</VAR> )</CODE> -<DD>Returns the value of <VAR>expression</VAR>. -This may be used to override the normal precedence of operators. -<P> - -<DT><CODE>! <VAR>expression</VAR></CODE> -<DD>True if <VAR>expression</VAR> is false. -<P> - -<DT><CODE><VAR>expression1</VAR> && <VAR>expression2</VAR></CODE> -<DD>True if both <VAR>expression1</VAR> and <VAR>expression2</VAR> are true. -<P> - -<DT><CODE><VAR>expression1</VAR> || <VAR>expression2</VAR></CODE> -<DD>True if either <VAR>expression1</VAR> or <VAR>expression2</VAR> is true. -</DL> -The <CODE>&&</CODE> and <CODE>||</CODE> operators do not evaluate <VAR>expression2</VAR> if the -value of <VAR>expression1</VAR> is sufficient to determine the return -value of the entire conditional expression. -<P> - -</DL> -<P> - -<A NAME="Command Grouping"></A> -<HR SIZE="6"> -<A NAME="SEC22"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC21"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC19"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.2.4.3 Grouping Commands </H4> -<!--docid::SEC22::--> -<P> - -Bash provides two ways to group a list of commands to be executed -as a unit. When commands are grouped, redirections may be applied -to the entire command list. For example, the output of all the -commands in the list may be redirected to a single stream. -</P><P> - -<DL COMPACT> -<DT><CODE>()</CODE> -<DD><TABLE><tr><td> </td><td class=example><pre>( <VAR>list</VAR> ) -</pre></td></tr></table><P> - -Placing a list of commands between parentheses causes a subshell -environment to be created (see section <A HREF="b.html#SEC51">3.7.3 Command Execution Environment</A>), and each -of the commands in <VAR>list</VAR> to be executed in that subshell. Since the -<VAR>list</VAR> is executed in a subshell, variable assignments do not remain in -effect after the subshell completes. -</P><P> - -<DT><CODE>{}</CODE> -<DD><A NAME="IDX43"></A> -<A NAME="IDX44"></A> -<TABLE><tr><td> </td><td class=example><pre>{ <VAR>list</VAR>; } -</pre></td></tr></table><P> - -Placing a list of commands between curly braces causes the list to -be executed in the current shell context. No subshell is created. -The semicolon (or newline) following <VAR>list</VAR> is required. -</DL> -<P> - -In addition to the creation of a subshell, there is a subtle difference -between these two constructs due to historical reasons. The braces -are <CODE>reserved words</CODE>, so they must be separated from the <VAR>list</VAR> -by <CODE>blank</CODE>s. The parentheses are <CODE>operators</CODE>, and are -recognized as separate tokens by the shell even if they are not separated -from the <VAR>list</VAR> by whitespace. -</P><P> - -The exit status of both of these constructs is the exit status of -<VAR>list</VAR>. -</P><P> - -<A NAME="Shell Functions"></A> -<HR SIZE="6"> -<A NAME="SEC23"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC22"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC24"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC24"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.3 Shell Functions </H2> -<!--docid::SEC23::--> -<P> - -Shell functions are a way to group commands for later execution -using a single name for the group. They are executed just like -a "regular" command. -When the name of a shell function is used as a simple command name, -the list of commands associated with that function name is executed. -Shell functions are executed in the current -shell context; no new process is created to interpret them. -</P><P> - -Functions are declared using this syntax: -<A NAME="IDX45"></A> -<TABLE><tr><td> </td><td class=example><pre>[ <CODE>function</CODE> ] <VAR>name</VAR> () <VAR>compound-command</VAR> [ <VAR>redirections</VAR> ] -</pre></td></tr></table></P><P> - -This defines a shell function named <VAR>name</VAR>. The reserved -word <CODE>function</CODE> is optional. -If the <CODE>function</CODE> reserved -word is supplied, the parentheses are optional. -The <VAR>body</VAR> of the function is the compound command -<VAR>compound-command</VAR> (see section <A HREF="b.html#SEC19">3.2.4 Compound Commands</A>). -That command is usually a <VAR>list</VAR> enclosed between { and }, but -may be any compound command listed above. -<VAR>compound-command</VAR> is executed whenever <VAR>name</VAR> is specified as the -name of a command. -Any redirections (see section <A HREF="b.html#SEC38">3.6 Redirections</A>) associated with the shell function -are performed when the function is executed. -</P><P> - -A function definition may be deleted using the <SAMP>`-f'</SAMP> option to the -<CODE>unset</CODE> builtin (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -</P><P> - -The exit status of a function definition is zero unless a syntax error -occurs or a readonly function with the same name already exists. -When executed, the exit status of a function is the exit status of the -last command executed in the body. -</P><P> - -Note that for historical reasons, in the most common usage the curly braces -that surround the body of the function must be separated from the body by -<CODE>blank</CODE>s or newlines. -This is because the braces are reserved words and are only recognized -as such when they are separated by whitespace. -Also, when using the braces, the <VAR>list</VAR> must be terminated by a semicolon, -a <SAMP>`&'</SAMP>, or a newline. -</P><P> - -When a function is executed, the arguments to the -function become the positional parameters -during its execution (see section <A HREF="b.html#SEC25">3.4.1 Positional Parameters</A>). -The special parameter <SAMP>`#'</SAMP> that expands to the number of -positional parameters is updated to reflect the change. -Special parameter <CODE>0</CODE> is unchanged. -The first element of the <CODE>FUNCNAME</CODE> variable is set to the -name of the function while the function is executing. -All other aspects of the shell execution -environment are identical between a function and its caller -with the exception that the <CODE>DEBUG</CODE> and <CODE>RETURN</CODE> traps -are not inherited unless the function has been given the -<CODE>trace</CODE> attribute using the <CODE>declare</CODE> builtin or -the <CODE>-o functrace</CODE> option has been enabled with -the <CODE>set</CODE> builtin, -(in which case all functions inherit the <CODE>DEBUG</CODE> and <CODE>RETURN</CODE> traps). -See section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>, for the description of the -<CODE>trap</CODE> builtin. -</P><P> - -If the builtin command <CODE>return</CODE> -is executed in a function, the function completes and -execution resumes with the next command after the function -call. -Any command associated with the <CODE>RETURN</CODE> trap is executed -before execution resumes. -When a function completes, the values of the -positional parameters and the special parameter <SAMP>`#'</SAMP> -are restored to the values they had prior to the function's -execution. If a numeric argument is given to <CODE>return</CODE>, -that is the function's return status; otherwise the function's -return status is the exit status of the last command executed -before the <CODE>return</CODE>. -</P><P> - -Variables local to the function may be declared with the -<CODE>local</CODE> builtin. These variables are visible only to -the function and the commands it invokes. -</P><P> - -Function names and definitions may be listed with the -<SAMP>`-f'</SAMP> option to the <CODE>declare</CODE> or <CODE>typeset</CODE> -builtin commands (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -The <SAMP>`-F'</SAMP> option to <CODE>declare</CODE> or <CODE>typeset</CODE> -will list the function names only -(and optionally the source file and line number, if the <CODE>extdebug</CODE> -shell option is enabled). -Functions may be exported so that subshells -automatically have them defined with the -<SAMP>`-f'</SAMP> option to the <CODE>export</CODE> builtin -(see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -Note that shell functions and variables with the same name may result -in multiple identically-named entries in the environment passed to the -shell's children. -Care should be taken in cases where this may cause a problem. -</P><P> - -Functions may be recursive. No limit is placed on the number of -recursive calls. -</P><P> - -<A NAME="Shell Parameters"></A> -<HR SIZE="6"> -<A NAME="SEC24"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC23"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC25"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.4 Shell Parameters </H2> -<!--docid::SEC24::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC25">3.4.1 Positional Parameters</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The shell's command-line arguments.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Parameters denoted by special characters.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -A <VAR>parameter</VAR> is an entity that stores values. -It can be a <CODE>name</CODE>, a number, or one of the special characters -listed below. -A <VAR>variable</VAR> is a parameter denoted by a <CODE>name</CODE>. -A variable has a <VAR>value</VAR> and zero or more <VAR>attributes</VAR>. -Attributes are assigned using the <CODE>declare</CODE> builtin command -(see the description of the <CODE>declare</CODE> builtin in <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -</P><P> - -A parameter is set if it has been assigned a value. The null string is -a valid value. Once a variable is set, it may be unset only by using -the <CODE>unset</CODE> builtin command. -</P><P> - -A variable may be assigned to by a statement of the form -<TABLE><tr><td> </td><td class=example><pre><VAR>name</VAR>=[<VAR>value</VAR>] -</pre></td></tr></table>If <VAR>value</VAR> -is not given, the variable is assigned the null string. All -<VAR>value</VAR>s undergo tilde expansion, parameter and variable expansion, -command substitution, arithmetic expansion, and quote -removal (detailed below). If the variable has its <CODE>integer</CODE> -attribute set, then <VAR>value</VAR> -is evaluated as an arithmetic expression even if the <CODE>$((<small>...</small>))</CODE> -expansion is not used (see section <A HREF="b.html#SEC32">3.5.5 Arithmetic Expansion</A>). -Word splitting is not performed, with the exception -of <CODE>"$@"</CODE> as explained below. -Filename expansion is not performed. -Assignment statements may also appear as arguments to the -<CODE>alias</CODE>, -<CODE>declare</CODE>, <CODE>typeset</CODE>, <CODE>export</CODE>, <CODE>readonly</CODE>, -and <CODE>local</CODE> builtin commands. -</P><P> - -In the context where an assignment statement is assigning a value -to a shell variable or array index (see section <A HREF="b.html#SEC83">6.7 Arrays</A>), the <SAMP>`+='</SAMP> -operator can be used to -append to or add to the variable's previous value. -When <SAMP>`+='</SAMP> is applied to a variable for which the integer attribute -has been set, <VAR>value</VAR> is evaluated as an arithmetic expression and -added to the variable's current value, which is also evaluated. -When <SAMP>`+='</SAMP> is applied to an array variable using compound assignment -(see section <A HREF="b.html#SEC83">6.7 Arrays</A>), the -variable's value is not unset (as it is when using <SAMP>`='</SAMP>), and new -values are appended to the array beginning at one greater than the array's -maximum index. -When applied to a string-valued variable, <VAR>value</VAR> is expanded and -appended to the variable's value. -</P><P> - -<A NAME="Positional Parameters"></A> -<HR SIZE="6"> -<A NAME="SEC25"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC24"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC26"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC24"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.4.1 Positional Parameters </H3> -<!--docid::SEC25::--> -<P> - -A <VAR>positional parameter</VAR> is a parameter denoted by one or more -digits, other than the single digit <CODE>0</CODE>. Positional parameters are -assigned from the shell's arguments when it is invoked, -and may be reassigned using the <CODE>set</CODE> builtin command. -Positional parameter <CODE>N</CODE> may be referenced as <CODE>${N}</CODE>, or -as <CODE>$N</CODE> when <CODE>N</CODE> consists of a single digit. -Positional parameters may not be assigned to with assignment statements. -The <CODE>set</CODE> and <CODE>shift</CODE> builtins are used to set and -unset them (see section <A HREF="b.html#SEC56">4. Shell Builtin Commands</A>). -The positional parameters are -temporarily replaced when a shell function is executed -(see section <A HREF="b.html#SEC23">3.3 Shell Functions</A>). -</P><P> - -When a positional parameter consisting of more than a single -digit is expanded, it must be enclosed in braces. -</P><P> - -<A NAME="Special Parameters"></A> -<HR SIZE="6"> -<A NAME="SEC26"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC25"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC24"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.4.2 Special Parameters </H3> -<!--docid::SEC26::--> -<P> - -The shell treats several parameters specially. These parameters may -only be referenced; assignment to them is not allowed. -</P><P> - -<DL COMPACT> - -<A NAME="IDX46"></A> -<DT><CODE>*</CODE> -<DD><A NAME="IDX47"></A> -Expands to the positional parameters, starting from one. When the -expansion occurs within double quotes, it expands to a single word -with the value of each parameter separated by the first character -of the <CODE>IFS</CODE> -special variable. That is, <CODE>"$*"</CODE> is equivalent -to <CODE>"$1<VAR>c</VAR>$2<VAR>c</VAR><small>...</small>"</CODE>, where <VAR>c</VAR> -is the first character of the value of the <CODE>IFS</CODE> -variable. -If <CODE>IFS</CODE> is unset, the parameters are separated by spaces. -If <CODE>IFS</CODE> is null, the parameters are joined without intervening -separators. -<P> - -<A NAME="IDX48"></A> -<DT><CODE>@</CODE> -<DD><A NAME="IDX49"></A> -Expands to the positional parameters, starting from one. When the -expansion occurs within double quotes, each parameter expands to a -separate word. That is, <CODE>"$@"</CODE> is equivalent to -<CODE>"$1" "$2" <small>...</small></CODE>. -If the double-quoted expansion occurs within a word, the expansion of -the first parameter is joined with the beginning part of the original -word, and the expansion of the last parameter is joined with the last -part of the original word. -When there are no positional parameters, <CODE>"$@"</CODE> and -<CODE>$@</CODE> -expand to nothing (i.e., they are removed). -<P> - -<A NAME="IDX50"></A> -<DT><CODE>#</CODE> -<DD><A NAME="IDX51"></A> -Expands to the number of positional parameters in decimal. -<P> - -<A NAME="IDX52"></A> -<DT><CODE>?</CODE> -<DD><A NAME="IDX53"></A> -Expands to the exit status of the most recently executed foreground -pipeline. -<P> - -<A NAME="IDX54"></A> -<DT><CODE>-</CODE> -<DD><A NAME="IDX55"></A> -(A hyphen.) Expands to the current option flags as specified upon -invocation, by the <CODE>set</CODE> -builtin command, or those set by the shell itself -(such as the <SAMP>`-i'</SAMP> option). -<P> - -<A NAME="IDX56"></A> -<DT><CODE>$</CODE> -<DD><A NAME="IDX57"></A> -Expands to the process ID of the shell. In a <CODE>()</CODE> subshell, it -expands to the process ID of the invoking shell, not the subshell. -<P> - -<A NAME="IDX58"></A> -<DT><CODE>!</CODE> -<DD><A NAME="IDX59"></A> -Expands to the process ID of the most recently executed background -(asynchronous) command. -<P> - -<A NAME="IDX60"></A> -<DT><CODE>0</CODE> -<DD><A NAME="IDX61"></A> -Expands to the name of the shell or shell script. This is set at -shell initialization. If Bash is invoked with a file of commands -(see section <A HREF="b.html#SEC55">3.8 Shell Scripts</A>), <CODE>$0</CODE> is set to the name of that file. -If Bash is started with the <SAMP>`-c'</SAMP> option (see section <A HREF="b.html#SEC67">6.1 Invoking Bash</A>), -then <CODE>$0</CODE> is set to the first argument after the string to be -executed, if one is present. Otherwise, it is set -to the filename used to invoke Bash, as given by argument zero. -<P> - -<A NAME="IDX62"></A> -<DT><CODE>_</CODE> -<DD><A NAME="IDX63"></A> -(An underscore.) -At shell startup, set to the absolute pathname used to invoke the -shell or shell script being executed as passed in the environment -or argument list. -Subsequently, expands to the last argument to the previous command, -after expansion. -Also set to the full pathname used to invoke each command executed -and placed in the environment exported to that command. -When checking mail, this parameter holds the name of the mail file. -</DL> -<P> - -<A NAME="Shell Expansions"></A> -<HR SIZE="6"> -<A NAME="SEC27"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC26"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC28"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.5 Shell Expansions </H2> -<!--docid::SEC27::--> -<P> - -Expansion is performed on the command line after it has been split into -<CODE>token</CODE>s. There are seven kinds of expansion performed: -<UL> -<LI>brace expansion -<LI>tilde expansion -<LI>parameter and variable expansion -<LI>command substitution -<LI>arithmetic expansion -<LI>word splitting -<LI>filename expansion -</UL> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC28">3.5.1 Brace Expansion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Expansion of expressions within braces.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC29">3.5.2 Tilde Expansion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Expansion of the ~ character.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How Bash expands variables to their values.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC31">3.5.4 Command Substitution</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Using the output of a command as an argument.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC32">3.5.5 Arithmetic Expansion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to use arithmetic in shell expansions.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC33">3.5.6 Process Substitution</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A way to write and read to and from a - command.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC34">3.5.7 Word Splitting</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How the results of expansion are split into separate - arguments.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC35">3.5.8 Filename Expansion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A shorthand for specifying filenames matching patterns.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC37">3.5.9 Quote Removal</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How and when quote characters are removed from - words.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -The order of expansions is: brace expansion, tilde expansion, -parameter, variable, and arithmetic expansion and -command substitution -(done in a left-to-right fashion), word splitting, and filename -expansion. -</P><P> - -On systems that can support it, there is an additional expansion -available: <VAR>process substitution</VAR>. This is performed at the -same time as parameter, variable, and arithmetic expansion and -command substitution. -</P><P> - -Only brace expansion, word splitting, and filename expansion -can change the number of words of the expansion; other expansions -expand a single word to a single word. -The only exceptions to this are the expansions of -<CODE>"$@"</CODE> (see section <A HREF="b.html#SEC26">3.4.2 Special Parameters</A>) and <CODE>"${<VAR>name</VAR>[@]}"</CODE> -(see section <A HREF="b.html#SEC83">6.7 Arrays</A>). -</P><P> - -After all expansions, <CODE>quote removal</CODE> (see section <A HREF="b.html#SEC37">3.5.9 Quote Removal</A>) -is performed. -</P><P> - -<A NAME="Brace Expansion"></A> -<HR SIZE="6"> -<A NAME="SEC28"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC29"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.1 Brace Expansion </H3> -<!--docid::SEC28::--> -<P> - -Brace expansion is a mechanism by which arbitrary strings may be generated. -This mechanism is similar to -<VAR>filename expansion</VAR> (see section <A HREF="b.html#SEC35">3.5.8 Filename Expansion</A>), -but the file names generated need not exist. -Patterns to be brace expanded take the form of an optional <VAR>preamble</VAR>, -followed by either a series of comma-separated strings or a seqeunce expression -between a pair of braces, -followed by an optional <VAR>postscript</VAR>. -The preamble is prefixed to each string contained within the braces, and -the postscript is then appended to each resulting string, expanding left -to right. -</P><P> - -Brace expansions may be nested. -The results of each expanded string are not sorted; left to right order -is preserved. -For example, -<TABLE><tr><td> </td><td class=example><pre>bash$ echo a{d,c,b}e -ade ace abe -</pre></td></tr></table></P><P> - -A sequence expression takes the form <CODE>{<VAR>x</VAR>..<VAR>y</VAR>}</CODE>, -where <VAR>x</VAR> and <VAR>y</VAR> are either integers or single characters. -When integers are supplied, the expression expands to each number between -<VAR>x</VAR> and <VAR>y</VAR>, inclusive. -When characters are supplied, the expression expands to each character -lexicographically between <VAR>x</VAR> and <VAR>y</VAR>, inclusive. Note that -both <VAR>x</VAR> and <VAR>y</VAR> must be of the same type. -</P><P> - -Brace expansion is performed before any other expansions, -and any characters special to other expansions are preserved -in the result. It is strictly textual. Bash -does not apply any syntactic interpretation to the context of the -expansion or the text between the braces. -To avoid conflicts with parameter expansion, the string <SAMP>`${'</SAMP> -is not considered eligible for brace expansion. -</P><P> - -A correctly-formed brace expansion must contain unquoted opening -and closing braces, and at least one unquoted comma or a valid -sequence expression. -Any incorrectly formed brace expansion is left unchanged. -</P><P> - -A { or <SAMP>`,'</SAMP> may be quoted with a backslash to prevent its -being considered part of a brace expression. -To avoid conflicts with parameter expansion, the string <SAMP>`${'</SAMP> -is not considered eligible for brace expansion. -</P><P> - -This construct is typically used as shorthand when the common -prefix of the strings to be generated is longer than in the -above example: -<TABLE><tr><td> </td><td class=example><pre>mkdir /usr/local/src/bash/{old,new,dist,bugs} -</pre></td></tr></table>or -<TABLE><tr><td> </td><td class=example><pre>chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}} -</pre></td></tr></table></P><P> - -<A NAME="Tilde Expansion"></A> -<HR SIZE="6"> -<A NAME="SEC29"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC28"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC30"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC30"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.2 Tilde Expansion </H3> -<!--docid::SEC29::--> -<P> - -If a word begins with an unquoted tilde character (<SAMP>`~'</SAMP>), all of the -characters up to the first unquoted slash (or all characters, -if there is no unquoted slash) are considered a <VAR>tilde-prefix</VAR>. -If none of the characters in the tilde-prefix are quoted, the -characters in the tilde-prefix following the tilde are treated as a -possible <VAR>login name</VAR>. -If this login name is the null string, the tilde is replaced with the -value of the <CODE>HOME</CODE> shell variable. -If <CODE>HOME</CODE> is unset, the home directory of the user executing the -shell is substituted instead. -Otherwise, the tilde-prefix is replaced with the home directory -associated with the specified login name. -</P><P> - -If the tilde-prefix is <SAMP>`~+'</SAMP>, the value of -the shell variable <CODE>PWD</CODE> replaces the tilde-prefix. -If the tilde-prefix is <SAMP>`~-'</SAMP>, the value of the shell variable -<CODE>OLDPWD</CODE>, if it is set, is substituted. -</P><P> - -If the characters following the tilde in the tilde-prefix consist of a -number <VAR>N</VAR>, optionally prefixed by a <SAMP>`+'</SAMP> or a <SAMP>`-'</SAMP>, -the tilde-prefix is replaced with the -corresponding element from the directory stack, as it would be displayed -by the <CODE>dirs</CODE> builtin invoked with the characters following tilde -in the tilde-prefix as an argument (see section <A HREF="b.html#SEC84">6.8 The Directory Stack</A>). -If the tilde-prefix, sans the tilde, consists of a number without a -leading <SAMP>`+'</SAMP> or <SAMP>`-'</SAMP>, <SAMP>`+'</SAMP> is assumed. -</P><P> - -If the login name is invalid, or the tilde expansion fails, the word is -left unchanged. -</P><P> - -Each variable assignment is checked for unquoted tilde-prefixes immediately -following a <SAMP>`:'</SAMP> or the first <SAMP>`='</SAMP>. -In these cases, tilde expansion is also performed. -Consequently, one may use file names with tildes in assignments to -<CODE>PATH</CODE>, <CODE>MAILPATH</CODE>, and <CODE>CDPATH</CODE>, -and the shell assigns the expanded value. -</P><P> - -The following table shows how Bash treats unquoted tilde-prefixes: -</P><P> - -<DL COMPACT> -<DT><CODE>~</CODE> -<DD>The value of <CODE>$HOME</CODE> -<DT><CODE>~/foo</CODE> -<DD><TT>`$HOME/foo'</TT> -<P> - -<DT><CODE>~fred/foo</CODE> -<DD>The subdirectory <CODE>foo</CODE> of the home directory of the user -<CODE>fred</CODE> -<P> - -<DT><CODE>~+/foo</CODE> -<DD><TT>`$PWD/foo'</TT> -<P> - -<DT><CODE>~-/foo</CODE> -<DD><TT>`${OLDPWD-'~-'}/foo'</TT> -<P> - -<DT><CODE>~<VAR>N</VAR></CODE> -<DD>The string that would be displayed by <SAMP>`dirs +<VAR>N</VAR>'</SAMP> -<P> - -<DT><CODE>~+<VAR>N</VAR></CODE> -<DD>The string that would be displayed by <SAMP>`dirs +<VAR>N</VAR>'</SAMP> -<P> - -<DT><CODE>~-<VAR>N</VAR></CODE> -<DD>The string that would be displayed by <SAMP>`dirs -<VAR>N</VAR>'</SAMP> -<P> - -</DL> -<P> - -<A NAME="Shell Parameter Expansion"></A> -<HR SIZE="6"> -<A NAME="SEC30"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC29"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC31"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC31"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.3 Shell Parameter Expansion </H3> -<!--docid::SEC30::--> -<P> - -The <SAMP>`$'</SAMP> character introduces parameter expansion, -command substitution, or arithmetic expansion. The parameter name -or symbol to be expanded may be enclosed in braces, which -are optional but serve to protect the variable to be expanded from -characters immediately following it which could be -interpreted as part of the name. -</P><P> - -When braces are used, the matching ending brace is the first <SAMP>`}'</SAMP> -not escaped by a backslash or within a quoted string, and not within an -embedded arithmetic expansion, command substitution, or parameter -expansion. -</P><P> - -The basic form of parameter expansion is ${<VAR>parameter</VAR>}. -The value of <VAR>parameter</VAR> is substituted. The braces are required -when <VAR>parameter</VAR> -is a positional parameter with more than one digit, -or when <VAR>parameter</VAR> -is followed by a character that is not to be -interpreted as part of its name. -</P><P> - -If the first character of <VAR>parameter</VAR> is an exclamation point, -a level of variable indirection is introduced. -Bash uses the value of the variable formed from the rest of -<VAR>parameter</VAR> as the name of the variable; this variable is then -expanded and that value is used in the rest of the substitution, rather -than the value of <VAR>parameter</VAR> itself. -This is known as <CODE>indirect expansion</CODE>. -The exceptions to this are the expansions of ${!<VAR>prefix*</VAR>} -and ${!<VAR>name</VAR>[@]} -described below. -The exclamation point must immediately follow the left brace in order to -introduce indirection. -</P><P> - -In each of the cases below, <VAR>word</VAR> is subject to tilde expansion, -parameter expansion, command substitution, and arithmetic expansion. -</P><P> - -When not performing substring expansion, Bash tests for a parameter -that is unset or null; omitting the colon results in a test only for a -parameter that is unset. Put another way, if the colon is included, -the operator tests for both existence and that the value is not null; -if the colon is omitted, the operator tests only for existence. -</P><P> - -<DL COMPACT> - -<DT><CODE>${<VAR>parameter</VAR>:-<VAR>word</VAR>}</CODE> -<DD>If <VAR>parameter</VAR> is unset or null, the expansion of -<VAR>word</VAR> is substituted. Otherwise, the value of -<VAR>parameter</VAR> is substituted. -<P> - -<DT><CODE>${<VAR>parameter</VAR>:=<VAR>word</VAR>}</CODE> -<DD>If <VAR>parameter</VAR> -is unset or null, the expansion of <VAR>word</VAR> -is assigned to <VAR>parameter</VAR>. -The value of <VAR>parameter</VAR> is then substituted. -Positional parameters and special parameters may not be assigned to -in this way. -<P> - -<DT><CODE>${<VAR>parameter</VAR>:?<VAR>word</VAR>}</CODE> -<DD>If <VAR>parameter</VAR> -is null or unset, the expansion of <VAR>word</VAR> (or a message -to that effect if <VAR>word</VAR> -is not present) is written to the standard error and the shell, if it -is not interactive, exits. Otherwise, the value of <VAR>parameter</VAR> is -substituted. -<P> - -<DT><CODE>${<VAR>parameter</VAR>:+<VAR>word</VAR>}</CODE> -<DD>If <VAR>parameter</VAR> -is null or unset, nothing is substituted, otherwise the expansion of -<VAR>word</VAR> is substituted. -<P> - -<DT><CODE>${<VAR>parameter</VAR>:<VAR>offset</VAR>}</CODE> -<DD><DT><CODE>${<VAR>parameter</VAR>:<VAR>offset</VAR>:<VAR>length</VAR>}</CODE> -<DD>Expands to up to <VAR>length</VAR> characters of <VAR>parameter</VAR> -starting at the character specified by <VAR>offset</VAR>. -If <VAR>length</VAR> is omitted, expands to the substring of -<VAR>parameter</VAR> starting at the character specified by <VAR>offset</VAR>. -<VAR>length</VAR> and <VAR>offset</VAR> are arithmetic expressions -(see section <A HREF="b.html#SEC81">6.5 Shell Arithmetic</A>). -This is referred to as Substring Expansion. -<P> - -<VAR>length</VAR> must evaluate to a number greater than or equal to zero. -If <VAR>offset</VAR> evaluates to a number less than zero, the value -is used as an offset from the end of the value of <VAR>parameter</VAR>. -If <VAR>parameter</VAR> is <SAMP>`@'</SAMP>, the result is <VAR>length</VAR> positional -parameters beginning at <VAR>offset</VAR>. -If <VAR>parameter</VAR> is an array name indexed by <SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, -the result is the <VAR>length</VAR> -members of the array beginning with <CODE>${<VAR>parameter</VAR>[<VAR>offset</VAR>]}</CODE>. -A negative <VAR>offset</VAR> is taken relative to one greater than the maximum -index of the specified array. -Note that a negative offset must be separated from the colon by at least -one space to avoid being confused with the <SAMP>`:-'</SAMP> expansion. -Substring indexing is zero-based unless the positional parameters -are used, in which case the indexing starts at 1 by default. -If <VAR>offset</VAR> is 0, and the positional parameters are used, <CODE>$@</CODE> is -prefixed to the list. -</P><P> - -<DT><CODE>${!<VAR>prefix</VAR>*}</CODE> -<DD><DT><CODE>${!<VAR>prefix</VAR>@}</CODE> -<DD>Expands to the names of variables whose names begin with <VAR>prefix</VAR>, -separated by the first character of the <CODE>IFS</CODE> special variable. -When <SAMP>`@'</SAMP> is used and the expansion appears within double quotes, each -variable name expands to a separate word. -<P> - -<DT><CODE>${!<VAR>name</VAR>[@]}</CODE> -<DD><DT><CODE>${!<VAR>name</VAR>[*]}</CODE> -<DD>If <VAR>name</VAR> is an array variable, expands to the list of array indices -(keys) assigned in <VAR>name</VAR>. -If <VAR>name</VAR> is not an array, expands to 0 if <VAR>name</VAR> is set and null -otherwise. -When <SAMP>`@'</SAMP> is used and the expansion appears within double quotes, each -key expands to a separate word. -<P> - -<DT><CODE>${#<VAR>parameter</VAR>}</CODE> -<DD>The length in characters of the expanded value of <VAR>parameter</VAR> is -substituted. -If <VAR>parameter</VAR> is <SAMP>`*'</SAMP> or <SAMP>`@'</SAMP>, the value substituted -is the number of positional parameters. -If <VAR>parameter</VAR> is an array name subscripted by <SAMP>`*'</SAMP> or <SAMP>`@'</SAMP>, -the value substituted is the number of elements in the array. -<P> - -<DT><CODE>${<VAR>parameter</VAR>#<VAR>word</VAR>}</CODE> -<DD><DT><CODE>${<VAR>parameter</VAR>##<VAR>word</VAR>}</CODE> -<DD>The <VAR>word</VAR> -is expanded to produce a pattern just as in filename -expansion (see section <A HREF="b.html#SEC35">3.5.8 Filename Expansion</A>). If the pattern matches -the beginning of the expanded value of <VAR>parameter</VAR>, -then the result of the expansion is the expanded value of <VAR>parameter</VAR> -with the shortest matching pattern (the <SAMP>`#'</SAMP> case) or the -longest matching pattern (the <SAMP>`##'</SAMP> case) deleted. -If <VAR>parameter</VAR> is <SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, -the pattern removal operation is applied to each positional -parameter in turn, and the expansion is the resultant list. -If <VAR>parameter</VAR> is an array variable subscripted with -<SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, -the pattern removal operation is applied to each member of the -array in turn, and the expansion is the resultant list. -<P> - -<DT><CODE>${<VAR>parameter</VAR>%<VAR>word</VAR>}</CODE> -<DD><DT><CODE>${<VAR>parameter</VAR>%%<VAR>word</VAR>}</CODE> -<DD>The <VAR>word</VAR> is expanded to produce a pattern just as in -filename expansion. -If the pattern matches a trailing portion of the expanded value of -<VAR>parameter</VAR>, then the result of the expansion is the value of -<VAR>parameter</VAR> with the shortest matching pattern (the <SAMP>`%'</SAMP> case) -or the longest matching pattern (the <SAMP>`%%'</SAMP> case) deleted. -If <VAR>parameter</VAR> is <SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, -the pattern removal operation is applied to each positional -parameter in turn, and the expansion is the resultant list. -If <VAR>parameter</VAR> -is an array variable subscripted with <SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, -the pattern removal operation is applied to each member of the -array in turn, and the expansion is the resultant list. -<P> - -<DT><CODE>${<VAR>parameter</VAR>/<VAR>pattern</VAR>/<VAR>string</VAR>}</CODE> -<DD><P> - -The <VAR>pattern</VAR> is expanded to produce a pattern just as in -filename expansion. -<VAR>Parameter</VAR> is expanded and the longest match of <VAR>pattern</VAR> -against its value is replaced with <VAR>string</VAR>. -If <VAR>pattern</VAR> begins with <SAMP>`/'</SAMP>, all matches of <VAR>pattern</VAR> are -replaced with <VAR>string</VAR>. Normally only the first match is replaced. -If <VAR>pattern</VAR> begins with <SAMP>`#'</SAMP>, it must match at the beginning -of the expanded value of <VAR>parameter</VAR>. -If <VAR>pattern</VAR> begins with <SAMP>`%'</SAMP>, it must match at the end -of the expanded value of <VAR>parameter</VAR>. -If <VAR>string</VAR> is null, matches of <VAR>pattern</VAR> are deleted -and the <CODE>/</CODE> following <VAR>pattern</VAR> may be omitted. -If <VAR>parameter</VAR> is <SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, -the substitution operation is applied to each positional -parameter in turn, and the expansion is the resultant list. -If <VAR>parameter</VAR> -is an array variable subscripted with <SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, -the substitution operation is applied to each member of the -array in turn, and the expansion is the resultant list. -</P><P> - -</DL> -<P> - -<A NAME="Command Substitution"></A> -<HR SIZE="6"> -<A NAME="SEC31"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC30"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC32"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC32"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.4 Command Substitution </H3> -<!--docid::SEC31::--> -<P> - -Command substitution allows the output of a command to replace -the command itself. -Command substitution occurs when a command is enclosed as follows: -<TABLE><tr><td> </td><td class=example><pre>$(<VAR>command</VAR>) -</pre></td></tr></table>or -<TABLE><tr><td> </td><td class=example><pre>`<VAR>command</VAR>` -</pre></td></tr></table></P><P> - -Bash performs the expansion by executing <VAR>command</VAR> and -replacing the command substitution with the standard output of the -command, with any trailing newlines deleted. -Embedded newlines are not deleted, but they may be removed during -word splitting. -The command substitution <CODE>$(cat <VAR>file</VAR>)</CODE> can be -replaced by the equivalent but faster <CODE>$(< <VAR>file</VAR>)</CODE>. -</P><P> - -When the old-style backquote form of substitution is used, -backslash retains its literal meaning except when followed by -<SAMP>`$'</SAMP>, <SAMP>``'</SAMP>, or <SAMP>`\'</SAMP>. -The first backquote not preceded by a backslash terminates the -command substitution. -When using the <CODE>$(<VAR>command</VAR>)</CODE> form, all characters between -the parentheses make up the command; none are treated specially. -</P><P> - -Command substitutions may be nested. To nest when using the backquoted -form, escape the inner backquotes with backslashes. -</P><P> - -If the substitution appears within double quotes, word splitting and -filename expansion are not performed on the results. -</P><P> - -<A NAME="Arithmetic Expansion"></A> -<HR SIZE="6"> -<A NAME="SEC32"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC31"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC33"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC33"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.5 Arithmetic Expansion </H3> -<!--docid::SEC32::--> -<P> - -Arithmetic expansion allows the evaluation of an arithmetic expression -and the substitution of the result. The format for arithmetic expansion is: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>$(( <VAR>expression</VAR> )) -</pre></td></tr></table></P><P> - -The expression is treated as if it were within double quotes, but -a double quote inside the parentheses is not treated specially. -All tokens in the expression undergo parameter expansion, command -substitution, and quote removal. -Arithmetic expansions may be nested. -</P><P> - -The evaluation is performed according to the rules listed below -(see section <A HREF="b.html#SEC81">6.5 Shell Arithmetic</A>). -If the expression is invalid, Bash prints a message indicating -failure to the standard error and no substitution occurs. -</P><P> - -<A NAME="Process Substitution"></A> -<HR SIZE="6"> -<A NAME="SEC33"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC32"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC34"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC34"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.6 Process Substitution </H3> -<!--docid::SEC33::--> -<P> - -Process substitution is supported on systems that support named -pipes (FIFOs) or the <TT>`/dev/fd'</TT> method of naming open files. -It takes the form of -<TABLE><tr><td> </td><td class=example><pre><(<VAR>list</VAR>) -</pre></td></tr></table>or -<TABLE><tr><td> </td><td class=example><pre>>(<VAR>list</VAR>) -</pre></td></tr></table>The process <VAR>list</VAR> is run with its input or output connected to a -FIFO or some file in <TT>`/dev/fd'</TT>. The name of this file is -passed as an argument to the current command as the result of the -expansion. If the <CODE>>(<VAR>list</VAR>)</CODE> form is used, writing to -the file will provide input for <VAR>list</VAR>. If the -<CODE><(<VAR>list</VAR>)</CODE> form is used, the file passed as an -argument should be read to obtain the output of <VAR>list</VAR>. -Note that no space may appear between the <CODE><</CODE> or <CODE>></CODE> -and the left parenthesis, otherwise the construct would be interpreted -as a redirection. -</P><P> - -When available, process substitution is performed simultaneously with -parameter and variable expansion, command substitution, and arithmetic -expansion. -</P><P> - -<A NAME="Word Splitting"></A> -<HR SIZE="6"> -<A NAME="SEC34"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC33"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC35"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC35"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.7 Word Splitting </H3> -<!--docid::SEC34::--> -<P> - -The shell scans the results of parameter expansion, command substitution, -and arithmetic expansion that did not occur within double quotes for -word splitting. -</P><P> - -The shell treats each character of <CODE>$IFS</CODE> as a delimiter, and splits -the results of the other expansions into words on these characters. -If <CODE>IFS</CODE> is unset, or its value is exactly <CODE><space><tab><newline></CODE>, -the default, then sequences of -<CODE> <space></CODE>, <CODE><tab></CODE>, and <CODE><newline></CODE> -at the beginning and end of the results of the previous -expansions are ignored, and any sequence of <CODE>IFS</CODE> -characters not at the beginning or end serves to delimit words. -If <CODE>IFS</CODE> has a value other than the default, then sequences of -the whitespace characters <CODE>space</CODE> and <CODE>tab</CODE> -are ignored at the beginning and end of the -word, as long as the whitespace character is in the -value of <CODE>IFS</CODE> (an <CODE>IFS</CODE> whitespace character). -Any character in <CODE>IFS</CODE> that is not <CODE>IFS</CODE> -whitespace, along with any adjacent <CODE>IFS</CODE> -whitespace characters, delimits a field. A sequence of <CODE>IFS</CODE> -whitespace characters is also treated as a delimiter. -If the value of <CODE>IFS</CODE> is null, no word splitting occurs. -</P><P> - -Explicit null arguments (<CODE>""</CODE> or <CODE>"</CODE>) are retained. -Unquoted implicit null arguments, resulting from the expansion of -parameters that have no values, are removed. -If a parameter with no value is expanded within double quotes, a -null argument results and is retained. -</P><P> - -Note that if no expansion occurs, no splitting -is performed. -</P><P> - -<A NAME="Filename Expansion"></A> -<HR SIZE="6"> -<A NAME="SEC35"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC34"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC36"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC37"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC37"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.8 Filename Expansion </H3> -<!--docid::SEC35::--> -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How the shell matches patterns.</TD></TR> -</TABLE></BLOCKQUOTE> -<A NAME="IDX64"></A> -<A NAME="IDX65"></A> -<A NAME="IDX66"></A> -<A NAME="IDX67"></A> -<P> - -After word splitting, unless the <SAMP>`-f'</SAMP> option has been set -(see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>), Bash scans each word for the characters -<SAMP>`*'</SAMP>, <SAMP>`?'</SAMP>, and <SAMP>`['</SAMP>. -If one of these characters appears, then the word is -regarded as a <VAR>pattern</VAR>, -and replaced with an alphabetically sorted list of -file names matching the pattern. If no matching file names are found, -and the shell option <CODE>nullglob</CODE> is disabled, the word is left -unchanged. -If the <CODE>nullglob</CODE> option is set, and no matches are found, the word -is removed. -If the <CODE>failglob</CODE> shell option is set, and no matches are found, -an error message is printed and the command is not executed. -If the shell option <CODE>nocaseglob</CODE> is enabled, the match is performed -without regard to the case of alphabetic characters. -</P><P> - -When a pattern is used for filename generation, the character <SAMP>`.'</SAMP> -at the start of a filename or immediately following a slash -must be matched explicitly, unless the shell option <CODE>dotglob</CODE> is set. -When matching a file name, the slash character must always be -matched explicitly. -In other cases, the <SAMP>`.'</SAMP> character is not treated specially. -</P><P> - -See the description of <CODE>shopt</CODE> in <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>, -for a description of the <CODE>nocaseglob</CODE>, <CODE>nullglob</CODE>, -<CODE>failglob</CODE>, and <CODE>dotglob</CODE> options. -</P><P> - -The <CODE>GLOBIGNORE</CODE> -shell variable may be used to restrict the set of filenames matching a -pattern. If <CODE>GLOBIGNORE</CODE> -is set, each matching filename that also matches one of the patterns in -<CODE>GLOBIGNORE</CODE> is removed from the list of matches. The filenames -<TT>`.'</TT> and <TT>`..'</TT> -are always ignored when <CODE>GLOBIGNORE</CODE> -is set and not null. -However, setting <CODE>GLOBIGNORE</CODE> to a non-null value has the effect of -enabling the <CODE>dotglob</CODE> -shell option, so all other filenames beginning with a -<SAMP>`.'</SAMP> will match. -To get the old behavior of ignoring filenames beginning with a -<SAMP>`.'</SAMP>, make <SAMP>`.*'</SAMP> one of the patterns in <CODE>GLOBIGNORE</CODE>. -The <CODE>dotglob</CODE> option is disabled when <CODE>GLOBIGNORE</CODE> -is unset. -</P><P> - -<A NAME="Pattern Matching"></A> -<HR SIZE="6"> -<A NAME="SEC36"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC35"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC37"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC37"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC35"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC37"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H4> 3.5.8.1 Pattern Matching </H4> -<!--docid::SEC36::--> -<P> - -Any character that appears in a pattern, other than the special pattern -characters described below, matches itself. -The NUL character may not occur in a pattern. -A backslash escapes the following character; the -escaping backslash is discarded when matching. -The special pattern characters must be quoted if they are to be matched -literally. -</P><P> - -The special pattern characters have the following meanings: -<DL COMPACT> -<DT><CODE>*</CODE> -<DD>Matches any string, including the null string. -<DT><CODE>?</CODE> -<DD>Matches any single character. -<DT><CODE>[<small>...</small>]</CODE> -<DD>Matches any one of the enclosed characters. A pair of characters -separated by a hyphen denotes a <VAR>range expression</VAR>; -any character that sorts between those two characters, inclusive, -using the current locale's collating sequence and character set, -is matched. If the first character following the -<SAMP>`['</SAMP> is a <SAMP>`!'</SAMP> or a <SAMP>`^'</SAMP> -then any character not enclosed is matched. A <SAMP>`-'</SAMP> -may be matched by including it as the first or last character -in the set. A <SAMP>`]'</SAMP> may be matched by including it as the first -character in the set. -The sorting order of characters in range expressions is determined by -the current locale and the value of the <CODE>LC_COLLATE</CODE> shell variable, -if set. -<P> - -For example, in the default C locale, <SAMP>`[a-dx-z]'</SAMP> is equivalent to -<SAMP>`[abcdxyz]'</SAMP>. Many locales sort characters in dictionary order, and in -these locales <SAMP>`[a-dx-z]'</SAMP> is typically not equivalent to <SAMP>`[abcdxyz]'</SAMP>; -it might be equivalent to <SAMP>`[aBbCcDdxXyYz]'</SAMP>, for example. To obtain -the traditional interpretation of ranges in bracket expressions, you can -force the use of the C locale by setting the <CODE>LC_COLLATE</CODE> or -<CODE>LC_ALL</CODE> environment variable to the value <SAMP>`C'</SAMP>. -</P><P> - -Within <SAMP>`['</SAMP> and <SAMP>`]'</SAMP>, <VAR>character classes</VAR> can be specified -using the syntax -<CODE>[:</CODE><VAR>class</VAR><CODE>:]</CODE>, where <VAR>class</VAR> is one of the -following classes defined in the POSIX standard: -<TABLE><tr><td> </td><td class=example><pre>alnum alpha ascii blank cntrl digit graph lower -print punct space upper word xdigit -</pre></td></tr></table>A character class matches any character belonging to that class. -The <CODE>word</CODE> character class matches letters, digits, and the character -<SAMP>`_'</SAMP>. -</P><P> - -Within <SAMP>`['</SAMP> and <SAMP>`]'</SAMP>, an <VAR>equivalence class</VAR> can be -specified using the syntax <CODE>[=</CODE><VAR>c</VAR><CODE>=]</CODE>, which -matches all characters with the same collation weight (as defined -by the current locale) as the character <VAR>c</VAR>. -</P><P> - -Within <SAMP>`['</SAMP> and <SAMP>`]'</SAMP>, the syntax <CODE>[.</CODE><VAR>symbol</VAR><CODE>.]</CODE> -matches the collating symbol <VAR>symbol</VAR>. -</DL> -<P> - -If the <CODE>extglob</CODE> shell option is enabled using the <CODE>shopt</CODE> -builtin, several extended pattern matching operators are recognized. -In the following description, a <VAR>pattern-list</VAR> is a list of one -or more patterns separated by a <SAMP>`|'</SAMP>. -Composite patterns may be formed using one or more of the following -sub-patterns: -</P><P> - -<DL COMPACT> -<DT><CODE>?(<VAR>pattern-list</VAR>)</CODE> -<DD>Matches zero or one occurrence of the given patterns. -<P> - -<DT><CODE>*(<VAR>pattern-list</VAR>)</CODE> -<DD>Matches zero or more occurrences of the given patterns. -<P> - -<DT><CODE>+(<VAR>pattern-list</VAR>)</CODE> -<DD>Matches one or more occurrences of the given patterns. -<P> - -<DT><CODE>@(<VAR>pattern-list</VAR>)</CODE> -<DD>Matches one of the given patterns. -<P> - -<DT><CODE>!(<VAR>pattern-list</VAR>)</CODE> -<DD>Matches anything except one of the given patterns. -</DL> -<P> - -<A NAME="Quote Removal"></A> -<HR SIZE="6"> -<A NAME="SEC37"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC36"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC27"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.5.9 Quote Removal </H3> -<!--docid::SEC37::--> -<P> - -After the preceding expansions, all unquoted occurrences of the -characters <SAMP>`\'</SAMP>, <SAMP>`''</SAMP>, and <SAMP>`"'</SAMP> that did not -result from one of the above expansions are removed. -</P><P> - -<A NAME="Redirections"></A> -<HR SIZE="6"> -<A NAME="SEC38"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC37"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC39"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.6 Redirections </H2> -<!--docid::SEC38::--> -<P> - -Before a command is executed, its input and output -may be <VAR>redirected</VAR> -using a special notation interpreted by the shell. -Redirection may also be used to open and close files for the -current shell execution environment. The following redirection -operators may precede or appear anywhere within a -simple command or may follow a command. -Redirections are processed in the order they appear, from -left to right. -</P><P> - -In the following descriptions, if the file descriptor number is -omitted, and the first character of the redirection operator is -<SAMP>`<'</SAMP>, the redirection refers to the standard input (file -descriptor 0). If the first character of the redirection operator -is <SAMP>`>'</SAMP>, the redirection refers to the standard output (file -descriptor 1). -</P><P> - -The word following the redirection operator in the following -descriptions, unless otherwise noted, is subjected to brace expansion, -tilde expansion, parameter expansion, command substitution, arithmetic -expansion, quote removal, filename expansion, and word splitting. -If it expands to more than one word, Bash reports an error. -</P><P> - -Note that the order of redirections is significant. For example, -the command -<TABLE><tr><td> </td><td class=example><pre>ls > <VAR>dirlist</VAR> 2>&1 -</pre></td></tr></table>directs both standard output (file descriptor 1) and standard error -(file descriptor 2) to the file <VAR>dirlist</VAR>, while the command -<TABLE><tr><td> </td><td class=example><pre>ls 2>&1 > <VAR>dirlist</VAR> -</pre></td></tr></table>directs only the standard output to file <VAR>dirlist</VAR>, -because the standard error was duplicated as standard output -before the standard output was redirected to <VAR>dirlist</VAR>. -</P><P> - -Bash handles several filenames specially when they are used in -redirections, as described in the following table: -</P><P> - -<DL COMPACT> -<DT><CODE>/dev/fd/<VAR>fd</VAR></CODE> -<DD>If <VAR>fd</VAR> is a valid integer, file descriptor <VAR>fd</VAR> is duplicated. -<P> - -<DT><CODE>/dev/stdin</CODE> -<DD>File descriptor 0 is duplicated. -<P> - -<DT><CODE>/dev/stdout</CODE> -<DD>File descriptor 1 is duplicated. -<P> - -<DT><CODE>/dev/stderr</CODE> -<DD>File descriptor 2 is duplicated. -<P> - -<DT><CODE>/dev/tcp/<VAR>host</VAR>/<VAR>port</VAR></CODE> -<DD>If <VAR>host</VAR> is a valid hostname or Internet address, and <VAR>port</VAR> -is an integer port number or service name, Bash attempts to open a TCP -connection to the corresponding socket. -<P> - -<DT><CODE>/dev/udp/<VAR>host</VAR>/<VAR>port</VAR></CODE> -<DD>If <VAR>host</VAR> is a valid hostname or Internet address, and <VAR>port</VAR> -is an integer port number or service name, Bash attempts to open a UDP -connection to the corresponding socket. -<P> - -</DL> -<P> - -A failure to open or create a file causes the redirection to fail. -</P><P> - -Redirections using file descriptors greater than 9 should be used with -care, as they may conflict with file descriptors the shell uses -internally. -</P><P> - -<HR SIZE="6"> -<A NAME="SEC39"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC40"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.1 Redirecting Input </H3> -<!--docid::SEC39::--> -Redirection of input causes the file whose name results from -the expansion of <VAR>word</VAR> -to be opened for reading on file descriptor <CODE>n</CODE>, -or the standard input (file descriptor 0) if <CODE>n</CODE> -is not specified. -<P> - -The general format for redirecting input is: -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]<<VAR>word</VAR> -</pre></td></tr></table></P><P> - -<HR SIZE="6"> -<A NAME="SEC40"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC39"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC41"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC41"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.2 Redirecting Output </H3> -<!--docid::SEC40::--> -Redirection of output causes the file whose name results from -the expansion of <VAR>word</VAR> -to be opened for writing on file descriptor <VAR>n</VAR>, -or the standard output (file descriptor 1) if <VAR>n</VAR> -is not specified. If the file does not exist it is created; -if it does exist it is truncated to zero size. -<P> - -The general format for redirecting output is: -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]>[|]<VAR>word</VAR> -</pre></td></tr></table></P><P> - -If the redirection operator is <SAMP>`>'</SAMP>, and the <CODE>noclobber</CODE> -option to the <CODE>set</CODE> builtin has been enabled, the redirection -will fail if the file whose name results from the expansion of -<VAR>word</VAR> exists and is a regular file. -If the redirection operator is <SAMP>`>|'</SAMP>, or the redirection operator is -<SAMP>`>'</SAMP> and the <CODE>noclobber</CODE> option is not enabled, the redirection -is attempted even if the file named by <VAR>word</VAR> exists. -</P><P> - -<HR SIZE="6"> -<A NAME="SEC41"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC40"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC42"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC42"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.3 Appending Redirected Output </H3> -<!--docid::SEC41::--> -Redirection of output in this fashion -causes the file whose name results from -the expansion of <VAR>word</VAR> -to be opened for appending on file descriptor <VAR>n</VAR>, -or the standard output (file descriptor 1) if <VAR>n</VAR> -is not specified. If the file does not exist it is created. -<P> - -The general format for appending output is: -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]>><VAR>word</VAR> -</pre></td></tr></table></P><P> - -<HR SIZE="6"> -<A NAME="SEC42"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC41"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC43"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC43"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.4 Redirecting Standard Output and Standard Error </H3> -<!--docid::SEC42::--> -Bash allows both the -standard output (file descriptor 1) and -the standard error output (file descriptor 2) -to be redirected to the file whose name is the -expansion of <VAR>word</VAR> with this construct. -<P> - -There are two formats for redirecting standard output and -standard error: -<TABLE><tr><td> </td><td class=example><pre>&><VAR>word</VAR> -</pre></td></tr></table>and -<TABLE><tr><td> </td><td class=example><pre>>&<VAR>word</VAR> -</pre></td></tr></table>Of the two forms, the first is preferred. -This is semantically equivalent to -<TABLE><tr><td> </td><td class=example><pre>><VAR>word</VAR> 2>&1 -</pre></td></tr></table></P><P> - -<HR SIZE="6"> -<A NAME="SEC43"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC42"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC44"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC44"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.5 Here Documents </H3> -<!--docid::SEC43::--> -This type of redirection instructs the shell to read input from the -current source until a line containing only <VAR>word</VAR> -(with no trailing blanks) is seen. All of -the lines read up to that point are then used as the standard -input for a command. -<P> - -The format of here-documents is: -<TABLE><tr><td> </td><td class=example><pre><<[-]<VAR>word</VAR> - <VAR>here-document</VAR> -<VAR>delimiter</VAR> -</pre></td></tr></table></P><P> - -No parameter expansion, command substitution, arithmetic expansion, -or filename expansion is performed on -<VAR>word</VAR>. If any characters in <VAR>word</VAR> are quoted, the -<VAR>delimiter</VAR> is the result of quote removal on <VAR>word</VAR>, -and the lines in the here-document are not expanded. -If <VAR>word</VAR> is unquoted, -all lines of the here-document are subjected to parameter expansion, -command substitution, and arithmetic expansion. In the latter -case, the character sequence <CODE>\newline</CODE> is ignored, and <SAMP>`\'</SAMP> -must be used to quote the characters -<SAMP>`\'</SAMP>, <SAMP>`$'</SAMP>, and <SAMP>``'</SAMP>. -</P><P> - -If the redirection operator is <SAMP>`<<-'</SAMP>, -then all leading tab characters are stripped from input lines and the -line containing <VAR>delimiter</VAR>. -This allows here-documents within shell scripts to be indented in a -natural fashion. -</P><P> - -<HR SIZE="6"> -<A NAME="SEC44"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC43"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC45"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC45"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.6 Here Strings </H3> -<!--docid::SEC44::--> -A variant of here documents, the format is: -<TABLE><tr><td> </td><td class=example><pre><<< <VAR>word</VAR> -</pre></td></tr></table><P> - -The <VAR>word</VAR> is expanded and supplied to the command on its standard -input. -</P><P> - -<HR SIZE="6"> -<A NAME="SEC45"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC44"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC46"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC46"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.7 Duplicating File Descriptors </H3> -<!--docid::SEC45::--> -The redirection operator -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]<&<VAR>word</VAR> -</pre></td></tr></table>is used to duplicate input file descriptors. -If <VAR>word</VAR> -expands to one or more digits, the file descriptor denoted by <VAR>n</VAR> -is made to be a copy of that file descriptor. -If the digits in <VAR>word</VAR> do not specify a file descriptor open for -input, a redirection error occurs. -If <VAR>word</VAR> -evaluates to <SAMP>`-'</SAMP>, file descriptor <VAR>n</VAR> is closed. If -<VAR>n</VAR> is not specified, the standard input (file descriptor 0) is used. -<P> - -The operator -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]>&<VAR>word</VAR> -</pre></td></tr></table>is used similarly to duplicate output file descriptors. If -<VAR>n</VAR> is not specified, the standard output (file descriptor 1) is used. -If the digits in <VAR>word</VAR> do not specify a file descriptor open for -output, a redirection error occurs. -As a special case, if <VAR>n</VAR> is omitted, and <VAR>word</VAR> does not -expand to one or more digits, the standard output and standard -error are redirected as described previously. -</P><P> - -<HR SIZE="6"> -<A NAME="SEC46"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC45"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC47"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC47"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.8 Moving File Descriptors </H3> -<!--docid::SEC46::--> -The redirection operator -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]<&<VAR>digit</VAR>- -</pre></td></tr></table>moves the file descriptor <VAR>digit</VAR> to file descriptor <VAR>n</VAR>, -or the standard input (file descriptor 0) if <VAR>n</VAR> is not specified. -<VAR>digit</VAR> is closed after being duplicated to <VAR>n</VAR>. -<P> - -Similarly, the redirection operator -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]>&<VAR>digit</VAR>- -</pre></td></tr></table>moves the file descriptor <VAR>digit</VAR> to file descriptor <VAR>n</VAR>, -or the standard output (file descriptor 1) if <VAR>n</VAR> is not specified. -</P><P> - -<HR SIZE="6"> -<A NAME="SEC47"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC46"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC38"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.6.9 Opening File Descriptors for Reading and Writing </H3> -<!--docid::SEC47::--> -The redirection operator -<TABLE><tr><td> </td><td class=example><pre>[<VAR>n</VAR>]<><VAR>word</VAR> -</pre></td></tr></table>causes the file whose name is the expansion of <VAR>word</VAR> -to be opened for both reading and writing on file descriptor -<VAR>n</VAR>, or on file descriptor 0 if <VAR>n</VAR> -is not specified. If the file does not exist, it is created. -<P> - -<A NAME="Executing Commands"></A> -<HR SIZE="6"> -<A NAME="SEC48"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC47"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC49"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.7 Executing Commands </H2> -<!--docid::SEC48::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC49">3.7.1 Simple Command Expansion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How Bash expands simple commands before - executing them.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC50">3.7.2 Command Search and Execution</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How Bash finds commands and runs them.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC51">3.7.3 Command Execution Environment</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The environment in which Bash - executes commands that are not - shell builtins.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC52">3.7.4 Environment</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The environment given to a command.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC53">3.7.5 Exit Status</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The status returned by commands and how Bash - interprets it.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC54">3.7.6 Signals</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What happens when Bash or a command it runs - receives a signal.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Simple Command Expansion"></A> -<HR SIZE="6"> -<A NAME="SEC49"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC50"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.7.1 Simple Command Expansion </H3> -<!--docid::SEC49::--> -<P> - -When a simple command is executed, the shell performs the following -expansions, assignments, and redirections, from left to right. -</P><P> - -<OL> -<LI> -The words that the parser has marked as variable assignments (those -preceding the command name) and redirections are saved for later -processing. -<P> - -<LI> -The words that are not variable assignments or redirections are -expanded (see section <A HREF="b.html#SEC27">3.5 Shell Expansions</A>). -If any words remain after expansion, the first word -is taken to be the name of the command and the remaining words are -the arguments. -<P> - -<LI> -Redirections are performed as described above (see section <A HREF="b.html#SEC38">3.6 Redirections</A>). -<P> - -<LI> -The text after the <SAMP>`='</SAMP> in each variable assignment undergoes tilde -expansion, parameter expansion, command substitution, arithmetic expansion, -and quote removal before being assigned to the variable. -</OL> -<P> - -If no command name results, the variable assignments affect the current -shell environment. Otherwise, the variables are added to the environment -of the executed command and do not affect the current shell environment. -If any of the assignments attempts to assign a value to a readonly variable, -an error occurs, and the command exits with a non-zero status. -</P><P> - -If no command name results, redirections are performed, but do not -affect the current shell environment. A redirection error causes the -command to exit with a non-zero status. -</P><P> - -If there is a command name left after expansion, execution proceeds as -described below. Otherwise, the command exits. If one of the expansions -contained a command substitution, the exit status of the command is -the exit status of the last command substitution performed. If there -were no command substitutions, the command exits with a status of zero. -</P><P> - -<A NAME="Command Search and Execution"></A> -<HR SIZE="6"> -<A NAME="SEC50"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC49"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC51"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC51"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.7.2 Command Search and Execution </H3> -<!--docid::SEC50::--> -<P> - -After a command has been split into words, if it results in a -simple command and an optional list of arguments, the following -actions are taken. -</P><P> - -<OL> -<LI> -If the command name contains no slashes, the shell attempts to -locate it. If there exists a shell function by that name, that -function is invoked as described in <A HREF="b.html#SEC23">3.3 Shell Functions</A>. -<P> - -<LI> -If the name does not match a function, the shell searches for -it in the list of shell builtins. If a match is found, that -builtin is invoked. -<P> - -<LI> -If the name is neither a shell function nor a builtin, -and contains no slashes, Bash searches each element of -<CODE>$PATH</CODE> for a directory containing an executable file -by that name. Bash uses a hash table to remember the full -pathnames of executable files to avoid multiple <CODE>PATH</CODE> searches -(see the description of <CODE>hash</CODE> in <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -A full search of the directories in <CODE>$PATH</CODE> -is performed only if the command is not found in the hash table. -If the search is unsuccessful, the shell prints an error -message and returns an exit status of 127. -<P> - -<LI> -If the search is successful, or if the command name contains -one or more slashes, the shell executes the named program in -a separate execution environment. -Argument 0 is set to the name given, and the remaining arguments -to the command are set to the arguments supplied, if any. -<P> - -<LI> -If this execution fails because the file is not in executable -format, and the file is not a directory, it is assumed to be a -<VAR>shell script</VAR> and the shell executes it as described in -<A HREF="b.html#SEC55">3.8 Shell Scripts</A>. -<P> - -<LI> -If the command was not begun asynchronously, the shell waits for -the command to complete and collects its exit status. -<P> - -</OL> -<P> - -<A NAME="Command Execution Environment"></A> -<HR SIZE="6"> -<A NAME="SEC51"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC50"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC52"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC52"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.7.3 Command Execution Environment </H3> -<!--docid::SEC51::--> -<P> - -The shell has an <VAR>execution environment</VAR>, which consists of the -following: -</P><P> - -<UL> -<LI> -open files inherited by the shell at invocation, as modified by -redirections supplied to the <CODE>exec</CODE> builtin -<P> - -<LI> -the current working directory as set by <CODE>cd</CODE>, <CODE>pushd</CODE>, or -<CODE>popd</CODE>, or inherited by the shell at invocation -<P> - -<LI> -the file creation mode mask as set by <CODE>umask</CODE> or inherited from -the shell's parent -<P> - -<LI> -current traps set by <CODE>trap</CODE> -<P> - -<LI> -shell parameters that are set by variable assignment or with <CODE>set</CODE> -or inherited from the shell's parent in the environment -<P> - -<LI> -shell functions defined during execution or inherited from the shell's -parent in the environment -<P> - -<LI> -options enabled at invocation (either by default or with command-line -arguments) or by <CODE>set</CODE> -<P> - -<LI> -options enabled by <CODE>shopt</CODE> (see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>) -<P> - -<LI> -shell aliases defined with <CODE>alias</CODE> (see section <A HREF="b.html#SEC82">6.6 Aliases</A>) -<P> - -<LI> -various process IDs, including those of background jobs -(see section <A HREF="b.html#SEC18">3.2.3 Lists of Commands</A>), the value of <CODE>$$</CODE>, and the value of -<CODE>$PPID</CODE> -<P> - -</UL> -<P> - -When a simple command other than a builtin or shell function -is to be executed, it -is invoked in a separate execution environment that consists of -the following. Unless otherwise noted, the values are inherited -from the shell. -</P><P> - -<UL> -<LI> -the shell's open files, plus any modifications and additions specified -by redirections to the command -<P> - -<LI> -the current working directory -<P> - -<LI> -the file creation mode mask -<P> - -<LI> -shell variables and functions marked for export, along with variables -exported for the command, passed in the environment (see section <A HREF="b.html#SEC52">3.7.4 Environment</A>) -<P> - -<LI> -traps caught by the shell are reset to the values inherited from the -shell's parent, and traps ignored by the shell are ignored -<P> - -</UL> -<P> - -A command invoked in this separate environment cannot affect the -shell's execution environment. -</P><P> - -Command substitution, commands grouped with parentheses, -and asynchronous commands are invoked in a -subshell environment that is a duplicate of the shell environment, -except that traps caught by the shell are reset to the values -that the shell inherited from its parent at invocation. Builtin -commands that are invoked as part of a pipeline are also executed -in a subshell environment. Changes made to the subshell environment -cannot affect the shell's execution environment. -</P><P> - -If a command is followed by a <SAMP>`&'</SAMP> and job control is not active, the -default standard input for the command is the empty file <TT>`/dev/null'</TT>. -Otherwise, the invoked command inherits the file descriptors of the calling -shell as modified by redirections. -</P><P> - -<A NAME="Environment"></A> -<HR SIZE="6"> -<A NAME="SEC52"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC51"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC53"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC53"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.7.4 Environment </H3> -<!--docid::SEC52::--> -<P> - -When a program is invoked it is given an array of strings -called the <VAR>environment</VAR>. -This is a list of name-value pairs, of the form <CODE>name=value</CODE>. -</P><P> - -Bash provides several ways to manipulate the environment. -On invocation, the shell scans its own environment and -creates a parameter for each name found, automatically marking -it for <VAR>export</VAR> -to child processes. Executed commands inherit the environment. -The <CODE>export</CODE> and <SAMP>`declare -x'</SAMP> -commands allow parameters and functions to be added to and -deleted from the environment. If the value of a parameter -in the environment is modified, the new value becomes part -of the environment, replacing the old. The environment -inherited by any executed command consists of the shell's -initial environment, whose values may be modified in the shell, -less any pairs removed by the <CODE>unset</CODE> and <SAMP>`export -n'</SAMP> -commands, plus any additions via the <CODE>export</CODE> and -<SAMP>`declare -x'</SAMP> commands. -</P><P> - -The environment for any simple command -or function may be augmented temporarily by prefixing it with -parameter assignments, as described in <A HREF="b.html#SEC24">3.4 Shell Parameters</A>. -These assignment statements affect only the environment seen -by that command. -</P><P> - -If the <SAMP>`-k'</SAMP> option is set (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>), then all -parameter assignments are placed in the environment for a command, -not just those that precede the command name. -</P><P> - -When Bash invokes an external command, the variable <SAMP>`$_'</SAMP> -is set to the full path name of the command and passed to that -command in its environment. -</P><P> - -<A NAME="Exit Status"></A> -<HR SIZE="6"> -<A NAME="SEC53"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC52"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC54"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC54"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.7.5 Exit Status </H3> -<!--docid::SEC53::--> -<P> - -For the shell's purposes, a command which exits with a -zero exit status has succeeded. -A non-zero exit status indicates failure. -This seemingly counter-intuitive scheme is used so there -is one well-defined way to indicate success and a variety of -ways to indicate various failure modes. -When a command terminates on a fatal signal whose number is <VAR>N</VAR>, -Bash uses the value 128+<VAR>N</VAR> as the exit status. -</P><P> - -If a command is not found, the child process created to -execute it returns a status of 127. If a command is found -but is not executable, the return status is 126. -</P><P> - -If a command fails because of an error during expansion or redirection, -the exit status is greater than zero. -</P><P> - -The exit status is used by the Bash conditional commands -(see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>) and some of the list -constructs (see section <A HREF="b.html#SEC18">3.2.3 Lists of Commands</A>). -</P><P> - -All of the Bash builtins return an exit status of zero if they succeed -and a non-zero status on failure, so they may be used by the -conditional and list constructs. -All builtins return an exit status of 2 to indicate incorrect usage. -</P><P> - -<A NAME="Signals"></A> -<HR SIZE="6"> -<A NAME="SEC54"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC53"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC48"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 3.7.6 Signals </H3> -<!--docid::SEC54::--> -<P> - -When Bash is interactive, in the absence of any traps, it ignores -<CODE>SIGTERM</CODE> (so that <SAMP>`kill 0'</SAMP> does not kill an interactive shell), -and <CODE>SIGINT</CODE> -is caught and handled (so that the <CODE>wait</CODE> builtin is interruptible). -When Bash receives a <CODE>SIGINT</CODE>, it breaks out of any executing loops. -In all cases, Bash ignores <CODE>SIGQUIT</CODE>. -If job control is in effect (see section <A HREF="b.html#SEC89">7. Job Control</A>), Bash -ignores <CODE>SIGTTIN</CODE>, <CODE>SIGTTOU</CODE>, and <CODE>SIGTSTP</CODE>. -</P><P> - -Non-builtin commands started by Bash have signal handlers set to the -values inherited by the shell from its parent. -When job control is not in effect, asynchronous commands -ignore <CODE>SIGINT</CODE> and <CODE>SIGQUIT</CODE> in addition to these inherited -handlers. -Commands run as a result of -command substitution ignore the keyboard-generated job control signals -<CODE>SIGTTIN</CODE>, <CODE>SIGTTOU</CODE>, and <CODE>SIGTSTP</CODE>. -</P><P> - -The shell exits by default upon receipt of a <CODE>SIGHUP</CODE>. -Before exiting, an interactive shell resends the <CODE>SIGHUP</CODE> to -all jobs, running or stopped. -Stopped jobs are sent <CODE>SIGCONT</CODE> to ensure that they receive -the <CODE>SIGHUP</CODE>. -To prevent the shell from sending the <CODE>SIGHUP</CODE> signal to a -particular job, it should be removed -from the jobs table with the <CODE>disown</CODE> -builtin (see section <A HREF="b.html#SEC91">7.2 Job Control Builtins</A>) or marked -to not receive <CODE>SIGHUP</CODE> using <CODE>disown -h</CODE>. -</P><P> - -If the <CODE>huponexit</CODE> shell option has been set with <CODE>shopt</CODE> -(see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>), Bash sends a <CODE>SIGHUP</CODE> to all jobs when -an interactive login shell exits. -</P><P> - -If Bash is waiting for a command to complete and receives a signal -for which a trap has been set, the trap will not be executed until -the command completes. -When Bash is waiting for an asynchronous -command via the <CODE>wait</CODE> builtin, the reception of a signal for -which a trap has been set will cause the <CODE>wait</CODE> builtin to return -immediately with an exit status greater than 128, immediately after -which the trap is executed. -</P><P> - -<A NAME="Shell Scripts"></A> -<HR SIZE="6"> -<A NAME="SEC55"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC54"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC5"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 3.8 Shell Scripts </H2> -<!--docid::SEC55::--> -<P> - -A shell script is a text file containing shell commands. When such -a file is used as the first non-option argument when invoking Bash, -and neither the <SAMP>`-c'</SAMP> nor <SAMP>`-s'</SAMP> option is supplied -(see section <A HREF="b.html#SEC67">6.1 Invoking Bash</A>), -Bash reads and executes commands from the file, then exits. This -mode of operation creates a non-interactive shell. The shell first -searches for the file in the current directory, and looks in the -directories in <CODE>$PATH</CODE> if not found there. -</P><P> - -When Bash runs -a shell script, it sets the special parameter <CODE>0</CODE> to the name -of the file, rather than the name of the shell, and the positional -parameters are set to the remaining arguments, if any are given. -If no additional arguments are supplied, the positional parameters -are unset. -</P><P> - -A shell script may be made executable by using the <CODE>chmod</CODE> command -to turn on the execute bit. When Bash finds such a file while -searching the <CODE>$PATH</CODE> for a command, it spawns a subshell to -execute it. In other words, executing -<TABLE><tr><td> </td><td class=example><pre>filename <VAR>arguments</VAR> -</pre></td></tr></table>is equivalent to executing -<TABLE><tr><td> </td><td class=example><pre>bash filename <VAR>arguments</VAR> -</pre></td></tr></table></P><P> - -if <CODE>filename</CODE> is an executable shell script. -This subshell reinitializes itself, so that the effect is as if a -new shell had been invoked to interpret the script, with the -exception that the locations of commands remembered by the parent -(see the description of <CODE>hash</CODE> in <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>) -are retained by the child. -</P><P> - -Most versions of Unix make this a part of the operating system's command -execution mechanism. If the first line of a script begins with -the two characters <SAMP>`#!'</SAMP>, the remainder of the line specifies -an interpreter for the program. -Thus, you can specify Bash, <CODE>awk</CODE>, Perl, or some other -interpreter and write the rest of the script file in that language. -</P><P> - -The arguments to the interpreter -consist of a single optional argument following the interpreter -name on the first line of the script file, followed by the name of -the script file, followed by the rest of the arguments. Bash -will perform this action on operating systems that do not handle it -themselves. Note that some older versions of Unix limit the interpreter -name and argument to a maximum of 32 characters. -</P><P> - -Bash scripts often begin with <CODE>#! /bin/bash</CODE> (assuming that -Bash has been installed in <TT>`/bin'</TT>), since this ensures that -Bash will be used to interpret the script, even if it is executed -under another shell. -</P><P> - -<A NAME="Shell Builtin Commands"></A> -<HR SIZE="6"> -<A NAME="SEC56"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC55"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC57"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 4. Shell Builtin Commands </H1> -<!--docid::SEC56::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Builtin commands inherited from the Bourne - Shell.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Table of builtins specific to Bash.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC59">4.3 Modifying Shell Behavior</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Builtins to modify shell attributes and - optional behavior.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC62">4.4 Special Builtins</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Builtin commands classified specially by - POSIX.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -Builtin commands are contained within the shell itself. -When the name of a builtin command is used as the first word of -a simple command (see section <A HREF="b.html#SEC16">3.2.1 Simple Commands</A>), the shell executes -the command directly, without invoking another program. -Builtin commands are necessary to implement functionality impossible -or inconvenient to obtain with separate utilities. -</P><P> - -This section briefly describes the builtins which Bash inherits from -the Bourne Shell, as well as the builtin commands which are unique -to or have been extended in Bash. -</P><P> - -Several builtin commands are described in other chapters: builtin -commands which provide the Bash interface to the job control -facilities (see section <A HREF="b.html#SEC91">7.2 Job Control Builtins</A>), the directory stack -(see section <A HREF="b.html#SEC85">6.8.1 Directory Stack Builtins</A>), the command history -(see section <A HREF="b.html#SEC119">9.2 Bash History Builtins</A>), and the programmable completion -facilities (see section <A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A>). -</P><P> - -Many of the builtins have been extended by POSIX or Bash. -</P><P> - -Unless otherwise noted, each builtin command documented as accepting -options preceded by <SAMP>`-'</SAMP> accepts <SAMP>`--'</SAMP> -to signify the end of the options. -For example, the <CODE>:</CODE>, <CODE>true</CODE>, <CODE>false</CODE>, and <CODE>test</CODE> -builtins do not accept options. -</P><P> - -<A NAME="Bourne Shell Builtins"></A> -<HR SIZE="6"> -<A NAME="SEC57"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC58"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 4.1 Bourne Shell Builtins </H2> -<!--docid::SEC57::--> -<P> - -The following shell builtin commands are inherited from the Bourne Shell. -These commands are implemented as specified by the POSIX standard. -</P><P> - -<DL COMPACT> -<DT><CODE>: (a colon)</CODE> -<DD><A NAME="IDX68"></A> -<TABLE><tr><td> </td><td class=example><pre>: [<VAR>arguments</VAR>] -</pre></td></tr></table>Do nothing beyond expanding <VAR>arguments</VAR> and performing redirections. -The return status is zero. -<P> - -<DT><CODE>. (a period)</CODE> -<DD><A NAME="IDX69"></A> -<TABLE><tr><td> </td><td class=example><pre>. <VAR>filename</VAR> [<VAR>arguments</VAR>] -</pre></td></tr></table>Read and execute commands from the <VAR>filename</VAR> argument in the -current shell context. If <VAR>filename</VAR> does not contain a slash, -the <CODE>PATH</CODE> variable is used to find <VAR>filename</VAR>. -When Bash is not in POSIX mode, the current directory is searched -if <VAR>filename</VAR> is not found in <CODE>$PATH</CODE>. -If any <VAR>arguments</VAR> are supplied, they become the positional -parameters when <VAR>filename</VAR> is executed. Otherwise the positional -parameters are unchanged. -The return status is the exit status of the last command executed, or -zero if no commands are executed. If <VAR>filename</VAR> is not found, or -cannot be read, the return status is non-zero. -This builtin is equivalent to <CODE>source</CODE>. -<P> - -<DT><CODE>break</CODE> -<DD><A NAME="IDX70"></A> -<TABLE><tr><td> </td><td class=example><pre>break [<VAR>n</VAR>] -</pre></td></tr></table>Exit from a <CODE>for</CODE>, <CODE>while</CODE>, <CODE>until</CODE>, or <CODE>select</CODE> loop. -If <VAR>n</VAR> is supplied, the <VAR>n</VAR>th enclosing loop is exited. -<VAR>n</VAR> must be greater than or equal to 1. -The return status is zero unless <VAR>n</VAR> is not greater than or equal to 1. -<P> - -<DT><CODE>cd</CODE> -<DD><A NAME="IDX71"></A> -<TABLE><tr><td> </td><td class=example><pre>cd [-L|-P] [<VAR>directory</VAR>] -</pre></td></tr></table>Change the current working directory to <VAR>directory</VAR>. -If <VAR>directory</VAR> is not given, the value of the <CODE>HOME</CODE> shell -variable is used. -If the shell variable <CODE>CDPATH</CODE> exists, it is used as a search path. -If <VAR>directory</VAR> begins with a slash, <CODE>CDPATH</CODE> is not used. -<P> - -The <SAMP>`-P'</SAMP> option means to not follow symbolic links; symbolic -links are followed by default or with the <SAMP>`-L'</SAMP> option. -If <VAR>directory</VAR> is <SAMP>`-'</SAMP>, it is equivalent to <CODE>$OLDPWD</CODE>. -</P><P> - -If a non-empty directory name from <CODE>CDPATH</CODE> is used, or if -<SAMP>`-'</SAMP> is the first argument, and the directory change is -successful, the absolute pathname of the new working directory is -written to the standard output. -</P><P> - -The return status is zero if the directory is successfully changed, -non-zero otherwise. -</P><P> - -<DT><CODE>continue</CODE> -<DD><A NAME="IDX72"></A> -<TABLE><tr><td> </td><td class=example><pre>continue [<VAR>n</VAR>] -</pre></td></tr></table>Resume the next iteration of an enclosing <CODE>for</CODE>, <CODE>while</CODE>, -<CODE>until</CODE>, or <CODE>select</CODE> loop. -If <VAR>n</VAR> is supplied, the execution of the <VAR>n</VAR>th enclosing loop -is resumed. -<VAR>n</VAR> must be greater than or equal to 1. -The return status is zero unless <VAR>n</VAR> is not greater than or equal to 1. -<P> - -<DT><CODE>eval</CODE> -<DD><A NAME="IDX73"></A> -<TABLE><tr><td> </td><td class=example><pre>eval [<VAR>arguments</VAR>] -</pre></td></tr></table>The arguments are concatenated together into a single command, which is -then read and executed, and its exit status returned as the exit status -of <CODE>eval</CODE>. -If there are no arguments or only empty arguments, the return status is -zero. -<P> - -<DT><CODE>exec</CODE> -<DD><A NAME="IDX74"></A> -<TABLE><tr><td> </td><td class=example><pre>exec [-cl] [-a <VAR>name</VAR>] [<VAR>command</VAR> [<VAR>arguments</VAR>]] -</pre></td></tr></table>If <VAR>command</VAR> -is supplied, it replaces the shell without creating a new process. -If the <SAMP>`-l'</SAMP> option is supplied, the shell places a dash at the -beginning of the zeroth argument passed to <VAR>command</VAR>. -This is what the <CODE>login</CODE> program does. -The <SAMP>`-c'</SAMP> option causes <VAR>command</VAR> to be executed with an empty -environment. -If <SAMP>`-a'</SAMP> is supplied, the shell passes <VAR>name</VAR> as the zeroth -argument to <VAR>command</VAR>. -If no <VAR>command</VAR> is specified, redirections may be used to affect -the current shell environment. If there are no redirection errors, the -return status is zero; otherwise the return status is non-zero. -<P> - -<DT><CODE>exit</CODE> -<DD><A NAME="IDX75"></A> -<TABLE><tr><td> </td><td class=example><pre>exit [<VAR>n</VAR>] -</pre></td></tr></table>Exit the shell, returning a status of <VAR>n</VAR> to the shell's parent. -If <VAR>n</VAR> is omitted, the exit status is that of the last command executed. -Any trap on <CODE>EXIT</CODE> is executed before the shell terminates. -<P> - -<DT><CODE>export</CODE> -<DD><A NAME="IDX76"></A> -<TABLE><tr><td> </td><td class=example><pre>export [-fn] [-p] [<VAR>name</VAR>[=<VAR>value</VAR>]] -</pre></td></tr></table>Mark each <VAR>name</VAR> to be passed to child processes -in the environment. If the <SAMP>`-f'</SAMP> option is supplied, the <VAR>name</VAR>s -refer to shell functions; otherwise the names refer to shell variables. -The <SAMP>`-n'</SAMP> option means to no longer mark each <VAR>name</VAR> for export. -If no <VAR>names</VAR> are supplied, or if the <SAMP>`-p'</SAMP> option is given, a -list of exported names is displayed. -The <SAMP>`-p'</SAMP> option displays output in a form that may be reused as input. -If a variable name is followed by =<VAR>value</VAR>, the value of -the variable is set to <VAR>value</VAR>. -<P> - -The return status is zero unless an invalid option is supplied, one of -the names is not a valid shell variable name, or <SAMP>`-f'</SAMP> is supplied -with a name that is not a shell function. -</P><P> - -<DT><CODE>getopts</CODE> -<DD><A NAME="IDX77"></A> -<TABLE><tr><td> </td><td class=example><pre>getopts <VAR>optstring</VAR> <VAR>name</VAR> [<VAR>args</VAR>] -</pre></td></tr></table><CODE>getopts</CODE> is used by shell scripts to parse positional parameters. -<VAR>optstring</VAR> contains the option characters to be recognized; if a -character is followed by a colon, the option is expected to have an -argument, which should be separated from it by white space. -The colon (<SAMP>`:'</SAMP>) and question mark (<SAMP>`?'</SAMP>) may not be -used as option characters. -Each time it is invoked, <CODE>getopts</CODE> -places the next option in the shell variable <VAR>name</VAR>, initializing -<VAR>name</VAR> if it does not exist, -and the index of the next argument to be processed into the -variable <CODE>OPTIND</CODE>. -<CODE>OPTIND</CODE> is initialized to 1 each time the shell or a shell script -is invoked. -When an option requires an argument, -<CODE>getopts</CODE> places that argument into the variable <CODE>OPTARG</CODE>. -The shell does not reset <CODE>OPTIND</CODE> automatically; it must be manually -reset between multiple calls to <CODE>getopts</CODE> within the same shell -invocation if a new set of parameters is to be used. -<P> - -When the end of options is encountered, <CODE>getopts</CODE> exits with a -return value greater than zero. -<CODE>OPTIND</CODE> is set to the index of the first non-option argument, -and <CODE>name</CODE> is set to <SAMP>`?'</SAMP>. -</P><P> - -<CODE>getopts</CODE> -normally parses the positional parameters, but if more arguments are -given in <VAR>args</VAR>, <CODE>getopts</CODE> parses those instead. -</P><P> - -<CODE>getopts</CODE> can report errors in two ways. If the first character of -<VAR>optstring</VAR> is a colon, <VAR>silent</VAR> -error reporting is used. In normal operation diagnostic messages -are printed when invalid options or missing option arguments are -encountered. -If the variable <CODE>OPTERR</CODE> -is set to 0, no error messages will be displayed, even if the first -character of <CODE>optstring</CODE> is not a colon. -</P><P> - -If an invalid option is seen, -<CODE>getopts</CODE> places <SAMP>`?'</SAMP> into <VAR>name</VAR> and, if not silent, -prints an error message and unsets <CODE>OPTARG</CODE>. -If <CODE>getopts</CODE> is silent, the option character found is placed in -<CODE>OPTARG</CODE> and no diagnostic message is printed. -</P><P> - -If a required argument is not found, and <CODE>getopts</CODE> -is not silent, a question mark (<SAMP>`?'</SAMP>) is placed in <VAR>name</VAR>, -<CODE>OPTARG</CODE> is unset, and a diagnostic message is printed. -If <CODE>getopts</CODE> is silent, then a colon (<SAMP>`:'</SAMP>) is placed in -<VAR>name</VAR> and <CODE>OPTARG</CODE> is set to the option character found. -</P><P> - -<DT><CODE>hash</CODE> -<DD><A NAME="IDX78"></A> -<TABLE><tr><td> </td><td class=example><pre>hash [-r] [-p <VAR>filename</VAR>] [-dt] [<VAR>name</VAR>] -</pre></td></tr></table>Remember the full pathnames of commands specified as <VAR>name</VAR> arguments, -so they need not be searched for on subsequent invocations. -The commands are found by searching through the directories listed in -<CODE>$PATH</CODE>. -The <SAMP>`-p'</SAMP> option inhibits the path search, and <VAR>filename</VAR> is -used as the location of <VAR>name</VAR>. -The <SAMP>`-r'</SAMP> option causes the shell to forget all remembered locations. -The <SAMP>`-d'</SAMP> option causes the shell to forget the remembered location -of each <VAR>name</VAR>. -If the <SAMP>`-t'</SAMP> option is supplied, the full pathname to which each -<VAR>name</VAR> corresponds is printed. If multiple <VAR>name</VAR> arguments are -supplied with <SAMP>`-t'</SAMP> the <VAR>name</VAR> is printed before the hashed -full pathname. -The <SAMP>`-l'</SAMP> option causes output to be displayed in a format -that may be reused as input. -If no arguments are given, or if only <SAMP>`-l'</SAMP> is supplied, -information about remembered commands is printed. -The return status is zero unless a <VAR>name</VAR> is not found or an invalid -option is supplied. -<P> - -<DT><CODE>pwd</CODE> -<DD><A NAME="IDX79"></A> -<TABLE><tr><td> </td><td class=example><pre>pwd [-LP] -</pre></td></tr></table>Print the absolute pathname of the current working directory. -If the <SAMP>`-P'</SAMP> option is supplied, the pathname printed will not -contain symbolic links. -If the <SAMP>`-L'</SAMP> option is supplied, the pathname printed may contain -symbolic links. -The return status is zero unless an error is encountered while -determining the name of the current directory or an invalid option -is supplied. -<P> - -<DT><CODE>readonly</CODE> -<DD><A NAME="IDX80"></A> -<TABLE><tr><td> </td><td class=example><pre>readonly [-apf] [<VAR>name</VAR>[=<VAR>value</VAR>]] <small>...</small> -</pre></td></tr></table>Mark each <VAR>name</VAR> as readonly. -The values of these names may not be changed by subsequent assignment. -If the <SAMP>`-f'</SAMP> option is supplied, each <VAR>name</VAR> refers to a shell -function. -The <SAMP>`-a'</SAMP> option means each <VAR>name</VAR> refers to an array variable. -If no <VAR>name</VAR> arguments are given, or if the <SAMP>`-p'</SAMP> -option is supplied, a list of all readonly names is printed. -The <SAMP>`-p'</SAMP> option causes output to be displayed in a format that -may be reused as input. -If a variable name is followed by =<VAR>value</VAR>, the value of -the variable is set to <VAR>value</VAR>. -The return status is zero unless an invalid option is supplied, one of -the <VAR>name</VAR> arguments is not a valid shell variable or function name, -or the <SAMP>`-f'</SAMP> option is supplied with a name that is not a shell function. -<P> - -<DT><CODE>return</CODE> -<DD><A NAME="IDX81"></A> -<TABLE><tr><td> </td><td class=example><pre>return [<VAR>n</VAR>] -</pre></td></tr></table>Cause a shell function to exit with the return value <VAR>n</VAR>. -If <VAR>n</VAR> is not supplied, the return value is the exit status of the -last command executed in the function. -This may also be used to terminate execution of a script being executed -with the <CODE>.</CODE> (or <CODE>source</CODE>) builtin, returning either <VAR>n</VAR> or -the exit status of the last command executed within the script as the exit -status of the script. -Any command associated with the <CODE>RETURN</CODE> trap is executed -before execution resumes after the function or script. -The return status is non-zero if <CODE>return</CODE> is used outside a function -and not during the execution of a script by <CODE>.</CODE> or <CODE>source</CODE>. -<P> - -<DT><CODE>shift</CODE> -<DD><A NAME="IDX82"></A> -<TABLE><tr><td> </td><td class=example><pre>shift [<VAR>n</VAR>] -</pre></td></tr></table>Shift the positional parameters to the left by <VAR>n</VAR>. -The positional parameters from <VAR>n</VAR>+1 <small>...</small> <CODE>$#</CODE> are -renamed to <CODE>$1</CODE> <small>...</small> <CODE>$#</CODE>-<VAR>n</VAR>. -Parameters represented by the numbers <CODE>$#</CODE> to <CODE>$#</CODE>-<VAR>n</VAR>+1 -are unset. -<VAR>n</VAR> must be a non-negative number less than or equal to <CODE>$#</CODE>. -If <VAR>n</VAR> is zero or greater than <CODE>$#</CODE>, the positional parameters -are not changed. -If <VAR>n</VAR> is not supplied, it is assumed to be 1. -The return status is zero unless <VAR>n</VAR> is greater than <CODE>$#</CODE> or -less than zero, non-zero otherwise. -<P> - -<DT><CODE>test</CODE> -<DD><DT><CODE>[</CODE> -<DD><A NAME="IDX83"></A> -<A NAME="IDX84"></A> -Evaluate a conditional expression <VAR>expr</VAR>. -Each operator and operand must be a separate argument. -Expressions are composed of the primaries described below in -<A HREF="b.html#SEC80">6.4 Bash Conditional Expressions</A>. -<CODE>test</CODE> does not accept any options, nor does it accept and ignore -an argument of <SAMP>`--'</SAMP> as signifying the end of options. -<P> - -When the <CODE>[</CODE> form is used, the last argument to the command must -be a <CODE>]</CODE>. -</P><P> - -Expressions may be combined using the following operators, listed in -decreasing order of precedence. -</P><P> - -<DL COMPACT> -<DT><CODE>! <VAR>expr</VAR></CODE> -<DD>True if <VAR>expr</VAR> is false. -<P> - -<DT><CODE>( <VAR>expr</VAR> )</CODE> -<DD>Returns the value of <VAR>expr</VAR>. -This may be used to override the normal precedence of operators. -<P> - -<DT><CODE><VAR>expr1</VAR> -a <VAR>expr2</VAR></CODE> -<DD>True if both <VAR>expr1</VAR> and <VAR>expr2</VAR> are true. -<P> - -<DT><CODE><VAR>expr1</VAR> -o <VAR>expr2</VAR></CODE> -<DD>True if either <VAR>expr1</VAR> or <VAR>expr2</VAR> is true. -</DL> -<P> - -The <CODE>test</CODE> and <CODE>[</CODE> builtins evaluate conditional -expressions using a set of rules based on the number of arguments. -</P><P> - -<DL COMPACT> -<DT>0 arguments -<DD>The expression is false. -<P> - -<DT>1 argument -<DD>The expression is true if and only if the argument is not null. -<P> - -<DT>2 arguments -<DD>If the first argument is <SAMP>`!'</SAMP>, the expression is true if and -only if the second argument is null. -If the first argument is one of the unary conditional operators -(see section <A HREF="b.html#SEC80">6.4 Bash Conditional Expressions</A>), the expression -is true if the unary test is true. -If the first argument is not a valid unary operator, the expression is -false. -<P> - -<DT>3 arguments -<DD>If the second argument is one of the binary conditional -operators (see section <A HREF="b.html#SEC80">6.4 Bash Conditional Expressions</A>), the -result of the expression is the result of the binary test using the -first and third arguments as operands. -If the first argument is <SAMP>`!'</SAMP>, the value is the negation of -the two-argument test using the second and third arguments. -If the first argument is exactly <SAMP>`('</SAMP> and the third argument is -exactly <SAMP>`)'</SAMP>, the result is the one-argument test of the second -argument. -Otherwise, the expression is false. -The <SAMP>`-a'</SAMP> and <SAMP>`-o'</SAMP> operators are considered binary operators -in this case. -<P> - -<DT>4 arguments -<DD>If the first argument is <SAMP>`!'</SAMP>, the result is the negation of -the three-argument expression composed of the remaining arguments. -Otherwise, the expression is parsed and evaluated according to -precedence using the rules listed above. -<P> - -<DT>5 or more arguments -<DD>The expression is parsed and evaluated according to precedence -using the rules listed above. -</DL> -<P> - -<DT><CODE>times</CODE> -<DD><A NAME="IDX85"></A> -<TABLE><tr><td> </td><td class=example><pre>times -</pre></td></tr></table>Print out the user and system times used by the shell and its children. -The return status is zero. -<P> - -<DT><CODE>trap</CODE> -<DD><A NAME="IDX86"></A> -<TABLE><tr><td> </td><td class=example><pre>trap [-lp] [<VAR>arg</VAR>] [<VAR>sigspec</VAR> <small>...</small>] -</pre></td></tr></table>The commands in <VAR>arg</VAR> are to be read and executed when the -shell receives signal <VAR>sigspec</VAR>. If <VAR>arg</VAR> is absent (and -there is a single <VAR>sigspec</VAR>) or -equal to <SAMP>`-'</SAMP>, each specified signal's disposition is reset -to the value it had when the shell was started. -If <VAR>arg</VAR> is the null string, then the signal specified by -each <VAR>sigspec</VAR> is ignored by the shell and commands it invokes. -If <VAR>arg</VAR> is not present and <SAMP>`-p'</SAMP> has been supplied, -the shell displays the trap commands associated with each <VAR>sigspec</VAR>. -If no arguments are supplied, or -only <SAMP>`-p'</SAMP> is given, <CODE>trap</CODE> prints the list of commands -associated with each signal number in a form that may be reused as -shell input. -The <SAMP>`-l'</SAMP> option causes the shell to print a list of signal names -and their corresponding numbers. -Each <VAR>sigspec</VAR> is either a signal name or a signal number. -Signal names are case insensitive and the <CODE>SIG</CODE> prefix is optional. -If a <VAR>sigspec</VAR> -is <CODE>0</CODE> or <CODE>EXIT</CODE>, <VAR>arg</VAR> is executed when the shell exits. -If a <VAR>sigspec</VAR> is <CODE>DEBUG</CODE>, the command <VAR>arg</VAR> is executed -before every simple command, <CODE>for</CODE> command, <CODE>case</CODE> command, -<CODE>select</CODE> command, every arithmetic <CODE>for</CODE> command, and before -the first command executes in a shell function. -Refer to the description of the <CODE>extglob</CODE> option to the -<CODE>shopt</CODE> builtin (see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>) for details of its -effect on the <CODE>DEBUG</CODE> trap. -If a <VAR>sigspec</VAR> is <CODE>ERR</CODE>, the command <VAR>arg</VAR> -is executed whenever a simple command has a non-zero exit status, -subject to the following conditions. -The <CODE>ERR</CODE> trap is not executed if the failed command is part of the -command list immediately following an <CODE>until</CODE> or <CODE>while</CODE> keyword, -part of the test in an <CODE>if</CODE> statement, -part of a <CODE>&&</CODE> or <CODE>||</CODE> list, or if the command's return -status is being inverted using <CODE>!</CODE>. -These are the same conditions obeyed by the <CODE>errexit</CODE> option. -If a <VAR>sigspec</VAR> is <CODE>RETURN</CODE>, the command <VAR>arg</VAR> is executed -each time a shell function or a script executed with the <CODE>.</CODE> or -<CODE>source</CODE> builtins finishes executing. -<P> - -Signals ignored upon entry to the shell cannot be trapped or reset. -Trapped signals that are not being ignored are reset to their original -values in a child process when it is created. -</P><P> - -The return status is zero unless a <VAR>sigspec</VAR> does not specify a -valid signal. -</P><P> - -<DT><CODE>umask</CODE> -<DD><A NAME="IDX87"></A> -<TABLE><tr><td> </td><td class=example><pre>umask [-p] [-S] [<VAR>mode</VAR>] -</pre></td></tr></table>Set the shell process's file creation mask to <VAR>mode</VAR>. If -<VAR>mode</VAR> begins with a digit, it is interpreted as an octal number; -if not, it is interpreted as a symbolic mode mask similar -to that accepted by the <CODE>chmod</CODE> command. If <VAR>mode</VAR> is -omitted, the current value of the mask is printed. If the <SAMP>`-S'</SAMP> -option is supplied without a <VAR>mode</VAR> argument, the mask is printed -in a symbolic format. -If the <SAMP>`-p'</SAMP> option is supplied, and <VAR>mode</VAR> -is omitted, the output is in a form that may be reused as input. -The return status is zero if the mode is successfully changed or if -no <VAR>mode</VAR> argument is supplied, and non-zero otherwise. -<P> - -Note that when the mode is interpreted as an octal number, each number -of the umask is subtracted from <CODE>7</CODE>. Thus, a umask of <CODE>022</CODE> -results in permissions of <CODE>755</CODE>. -</P><P> - -<DT><CODE>unset</CODE> -<DD><A NAME="IDX88"></A> -<TABLE><tr><td> </td><td class=example><pre>unset [-fv] [<VAR>name</VAR>] -</pre></td></tr></table>Each variable or function <VAR>name</VAR> is removed. -If no options are supplied, or the <SAMP>`-v'</SAMP> option is given, each -<VAR>name</VAR> refers to a shell variable. -If the <SAMP>`-f'</SAMP> option is given, the <VAR>name</VAR>s refer to shell -functions, and the function definition is removed. -Readonly variables and functions may not be unset. -The return status is zero unless a <VAR>name</VAR> is readonly. -</DL> -<P> - -<A NAME="Bash Builtins"></A> -<HR SIZE="6"> -<A NAME="SEC58"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC57"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC59"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC59"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 4.2 Bash Builtin Commands </H2> -<!--docid::SEC58::--> -<P> - -This section describes builtin commands which are unique to -or have been extended in Bash. -Some of these commands are specified in the POSIX standard. -</P><P> - -<DL COMPACT> - -<DT><CODE>alias</CODE> -<DD><A NAME="IDX89"></A> -<TABLE><tr><td> </td><td class=example><pre>alias [<CODE>-p</CODE>] [<VAR>name</VAR>[=<VAR>value</VAR>] <small>...</small>] -</pre></td></tr></table><P> - -Without arguments or with the <SAMP>`-p'</SAMP> option, <CODE>alias</CODE> prints -the list of aliases on the standard output in a form that allows -them to be reused as input. -If arguments are supplied, an alias is defined for each <VAR>name</VAR> -whose <VAR>value</VAR> is given. If no <VAR>value</VAR> is given, the name -and value of the alias is printed. -Aliases are described in <A HREF="b.html#SEC82">6.6 Aliases</A>. -</P><P> - -<DT><CODE>bind</CODE> -<DD><A NAME="IDX90"></A> -<TABLE><tr><td> </td><td class=example><pre>bind [-m <VAR>keymap</VAR>] [-lpsvPSV] -bind [-m <VAR>keymap</VAR>] [-q <VAR>function</VAR>] [-u <VAR>function</VAR>] [-r <VAR>keyseq</VAR>] -bind [-m <VAR>keymap</VAR>] -f <VAR>filename</VAR> -bind [-m <VAR>keymap</VAR>] -x <VAR>keyseq:shell-command</VAR> -bind [-m <VAR>keymap</VAR>] <VAR>keyseq:function-name</VAR> -bind <VAR>readline-command</VAR> -</pre></td></tr></table><P> - -Display current Readline (see section <A HREF="b.html#SEC93">8. Command Line Editing</A>) -key and function bindings, -bind a key sequence to a Readline function or macro, -or set a Readline variable. -Each non-option argument is a command as it would appear in a -Readline initialization file (see section <A HREF="b.html#SEC101">8.3 Readline Init File</A>), -but each binding or command must be passed as a separate argument; e.g., -<SAMP>`"\C-x\C-r":re-read-init-file'</SAMP>. -Options, if supplied, have the following meanings: -</P><P> - -<DL COMPACT> -<DT><CODE>-m <VAR>keymap</VAR></CODE> -<DD>Use <VAR>keymap</VAR> as the keymap to be affected by -the subsequent bindings. Acceptable <VAR>keymap</VAR> -names are -<CODE>emacs</CODE>, -<CODE>emacs-standard</CODE>, -<CODE>emacs-meta</CODE>, -<CODE>emacs-ctlx</CODE>, -<CODE>vi</CODE>, -<CODE>vi-move</CODE>, -<CODE>vi-command</CODE>, and -<CODE>vi-insert</CODE>. -<CODE>vi</CODE> is equivalent to <CODE>vi-command</CODE>; -<CODE>emacs</CODE> is equivalent to <CODE>emacs-standard</CODE>. -<P> - -<DT><CODE>-l</CODE> -<DD>List the names of all Readline functions. -<P> - -<DT><CODE>-p</CODE> -<DD>Display Readline function names and bindings in such a way that they -can be used as input or in a Readline initialization file. -<P> - -<DT><CODE>-P</CODE> -<DD>List current Readline function names and bindings. -<P> - -<DT><CODE>-v</CODE> -<DD>Display Readline variable names and values in such a way that they -can be used as input or in a Readline initialization file. -<P> - -<DT><CODE>-V</CODE> -<DD>List current Readline variable names and values. -<P> - -<DT><CODE>-s</CODE> -<DD>Display Readline key sequences bound to macros and the strings they output -in such a way that they can be used as input or in a Readline -initialization file. -<P> - -<DT><CODE>-S</CODE> -<DD>Display Readline key sequences bound to macros and the strings they output. -<P> - -<DT><CODE>-f <VAR>filename</VAR></CODE> -<DD>Read key bindings from <VAR>filename</VAR>. -<P> - -<DT><CODE>-q <VAR>function</VAR></CODE> -<DD>Query about which keys invoke the named <VAR>function</VAR>. -<P> - -<DT><CODE>-u <VAR>function</VAR></CODE> -<DD>Unbind all keys bound to the named <VAR>function</VAR>. -<P> - -<DT><CODE>-r <VAR>keyseq</VAR></CODE> -<DD>Remove any current binding for <VAR>keyseq</VAR>. -<P> - -<DT><CODE>-x <VAR>keyseq:shell-command</VAR></CODE> -<DD>Cause <VAR>shell-command</VAR> to be executed whenever <VAR>keyseq</VAR> is -entered. -<P> - -</DL> -<P> - -The return status is zero unless an invalid option is supplied or an -error occurs. -</P><P> - -<DT><CODE>builtin</CODE> -<DD><A NAME="IDX91"></A> -<TABLE><tr><td> </td><td class=example><pre>builtin [<VAR>shell-builtin</VAR> [<VAR>args</VAR>]] -</pre></td></tr></table>Run a shell builtin, passing it <VAR>args</VAR>, and return its exit status. -This is useful when defining a shell function with the same -name as a shell builtin, retaining the functionality of the builtin within -the function. -The return status is non-zero if <VAR>shell-builtin</VAR> is not a shell -builtin command. -<P> - -<DT><CODE>caller</CODE> -<DD><A NAME="IDX92"></A> -<TABLE><tr><td> </td><td class=example><pre>caller [<VAR>expr</VAR>] -</pre></td></tr></table>Returns the context of any active subroutine call (a shell function or -a script executed with the <CODE>.</CODE> or <CODE>source</CODE> builtins). -<P> - -Without <VAR>expr</VAR>, <CODE>caller</CODE> displays the line number and source -filename of the current subroutine call. -If a non-negative integer is supplied as <VAR>expr</VAR>, <CODE>caller</CODE> -displays the line number, subroutine name, and source file corresponding -to that position in the current execution call stack. This extra -information may be used, for example, to print a stack trace. The -current frame is frame 0. -</P><P> - -The return value is 0 unless the shell is not executing a subroutine -call or <VAR>expr</VAR> does not correspond to a valid position in the -call stack. -</P><P> - -<DT><CODE>command</CODE> -<DD><A NAME="IDX93"></A> -<TABLE><tr><td> </td><td class=example><pre>command [-pVv] <VAR>command</VAR> [<VAR>arguments</VAR> <small>...</small>] -</pre></td></tr></table>Runs <VAR>command</VAR> with <VAR>arguments</VAR> ignoring any shell function -named <VAR>command</VAR>. -Only shell builtin commands or commands found by searching the -<CODE>PATH</CODE> are executed. -If there is a shell function named <CODE>ls</CODE>, running <SAMP>`command ls'</SAMP> -within the function will execute the external command <CODE>ls</CODE> -instead of calling the function recursively. -The <SAMP>`-p'</SAMP> option means to use a default value for <CODE>PATH</CODE> -that is guaranteed to find all of the standard utilities. -The return status in this case is 127 if <VAR>command</VAR> cannot be -found or an error occurred, and the exit status of <VAR>command</VAR> -otherwise. -<P> - -If either the <SAMP>`-V'</SAMP> or <SAMP>`-v'</SAMP> option is supplied, a -description of <VAR>command</VAR> is printed. The <SAMP>`-v'</SAMP> option -causes a single word indicating the command or file name used to -invoke <VAR>command</VAR> to be displayed; the <SAMP>`-V'</SAMP> option produces -a more verbose description. In this case, the return status is -zero if <VAR>command</VAR> is found, and non-zero if not. -</P><P> - -<DT><CODE>declare</CODE> -<DD><A NAME="IDX94"></A> -<TABLE><tr><td> </td><td class=example><pre>declare [-afFirtx] [-p] [<VAR>name</VAR>[=<VAR>value</VAR>] <small>...</small>] -</pre></td></tr></table><P> - -Declare variables and give them attributes. If no <VAR>name</VAR>s -are given, then display the values of variables instead. -</P><P> - -The <SAMP>`-p'</SAMP> option will display the attributes and values of each -<VAR>name</VAR>. -When <SAMP>`-p'</SAMP> is used, additional options are ignored. -The <SAMP>`-F'</SAMP> option inhibits the display of function definitions; -only the function name and attributes are printed. -If the <CODE>extdebug</CODE> shell option is enabled using <CODE>shopt</CODE> -(see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>), the source file name and line number where -the function is defined are displayed as well. -<SAMP>`-F'</SAMP> implies <SAMP>`-f'</SAMP>. -The following options can be used to restrict output to variables with -the specified attributes or to give variables attributes: -</P><P> - -<DL COMPACT> -<DT><CODE>-a</CODE> -<DD>Each <VAR>name</VAR> is an array variable (see section <A HREF="b.html#SEC83">6.7 Arrays</A>). -<P> - -<DT><CODE>-f</CODE> -<DD>Use function names only. -<P> - -<DT><CODE>-i</CODE> -<DD>The variable is to be treated as -an integer; arithmetic evaluation (see section <A HREF="b.html#SEC81">6.5 Shell Arithmetic</A>) is -performed when the variable is assigned a value. -<P> - -<DT><CODE>-r</CODE> -<DD>Make <VAR>name</VAR>s readonly. These names cannot then be assigned values -by subsequent assignment statements or unset. -<P> - -<DT><CODE>-t</CODE> -<DD>Give each <VAR>name</VAR> the <CODE>trace</CODE> attribute. -Traced functions inherit the <CODE>DEBUG</CODE> and <CODE>RETURN</CODE> traps from -the calling shell. -The trace attribute has no special meaning for variables. -<P> - -<DT><CODE>-x</CODE> -<DD>Mark each <VAR>name</VAR> for export to subsequent commands via -the environment. -</DL> -<P> - -Using <SAMP>`+'</SAMP> instead of <SAMP>`-'</SAMP> turns off the attribute instead, -with the exceptions that <SAMP>`+a'</SAMP> -may not be used to destroy an array variable and <SAMP>`+r'</SAMP> will not -remove the readonly attribute. -When used in a function, <CODE>declare</CODE> makes each <VAR>name</VAR> local, -as with the <CODE>local</CODE> command. If a variable name is followed by -=<VAR>value</VAR>, the value of the variable is set to <VAR>value</VAR>. -</P><P> - -The return status is zero unless an invalid option is encountered, -an attempt is made to define a function using <SAMP>`-f foo=bar'</SAMP>, -an attempt is made to assign a value to a readonly variable, -an attempt is made to assign a value to an array variable without -using the compound assignment syntax (see section <A HREF="b.html#SEC83">6.7 Arrays</A>), -one of the <VAR>names</VAR> is not a valid shell variable name, -an attempt is made to turn off readonly status for a readonly variable, -an attempt is made to turn off array status for an array variable, -or an attempt is made to display a non-existent function with <SAMP>`-f'</SAMP>. -</P><P> - -<DT><CODE>echo</CODE> -<DD><A NAME="IDX95"></A> -<TABLE><tr><td> </td><td class=example><pre>echo [-neE] [<VAR>arg</VAR> <small>...</small>] -</pre></td></tr></table>Output the <VAR>arg</VAR>s, separated by spaces, terminated with a -newline. -The return status is always 0. -If <SAMP>`-n'</SAMP> is specified, the trailing newline is suppressed. -If the <SAMP>`-e'</SAMP> option is given, interpretation of the following -backslash-escaped characters is enabled. -The <SAMP>`-E'</SAMP> option disables the interpretation of these escape characters, -even on systems where they are interpreted by default. -The <CODE>xpg_echo</CODE> shell option may be used to -dynamically determine whether or not <CODE>echo</CODE> expands these -escape characters by default. -<CODE>echo</CODE> does not interpret <SAMP>`--'</SAMP> to mean the end of options. -<P> - -<CODE>echo</CODE> interprets the following escape sequences: -<DL COMPACT> -<DT><CODE>\a</CODE> -<DD>alert (bell) -<DT><CODE>\b</CODE> -<DD>backspace -<DT><CODE>\c</CODE> -<DD>suppress trailing newline -<DT><CODE>\e</CODE> -<DD>escape -<DT><CODE>\f</CODE> -<DD>form feed -<DT><CODE>\n</CODE> -<DD>new line -<DT><CODE>\r</CODE> -<DD>carriage return -<DT><CODE>\t</CODE> -<DD>horizontal tab -<DT><CODE>\v</CODE> -<DD>vertical tab -<DT><CODE>\\</CODE> -<DD>backslash -<DT><CODE>\0<VAR>nnn</VAR></CODE> -<DD>the eight-bit character whose value is the octal value <VAR>nnn</VAR> -(zero to three octal digits) -<DT><CODE>\x<VAR>HH</VAR></CODE> -<DD>the eight-bit character whose value is the hexadecimal value <VAR>HH</VAR> -(one or two hex digits) -</DL> -<P> - -<DT><CODE>enable</CODE> -<DD><A NAME="IDX96"></A> -<TABLE><tr><td> </td><td class=example><pre>enable [-a] [-dnps] [-f <VAR>filename</VAR>] [<VAR>name</VAR> <small>...</small>] -</pre></td></tr></table>Enable and disable builtin shell commands. -Disabling a builtin allows a disk command which has the same name -as a shell builtin to be executed without specifying a full pathname, -even though the shell normally searches for builtins before disk commands. -If <SAMP>`-n'</SAMP> is used, the <VAR>name</VAR>s become disabled. Otherwise -<VAR>name</VAR>s are enabled. For example, to use the <CODE>test</CODE> binary -found via <CODE>$PATH</CODE> instead of the shell builtin version, type -<SAMP>`enable -n test'</SAMP>. -<P> - -If the <SAMP>`-p'</SAMP> option is supplied, or no <VAR>name</VAR> arguments appear, -a list of shell builtins is printed. With no other arguments, the list -consists of all enabled shell builtins. -The <SAMP>`-a'</SAMP> option means to list -each builtin with an indication of whether or not it is enabled. -</P><P> - -The <SAMP>`-f'</SAMP> option means to load the new builtin command <VAR>name</VAR> -from shared object <VAR>filename</VAR>, on systems that support dynamic loading. -The <SAMP>`-d'</SAMP> option will delete a builtin loaded with <SAMP>`-f'</SAMP>. -</P><P> - -If there are no options, a list of the shell builtins is displayed. -The <SAMP>`-s'</SAMP> option restricts <CODE>enable</CODE> to the POSIX special -builtins. If <SAMP>`-s'</SAMP> is used with <SAMP>`-f'</SAMP>, the new builtin becomes -a special builtin (see section <A HREF="b.html#SEC62">4.4 Special Builtins</A>). -</P><P> - -The return status is zero unless a <VAR>name</VAR> is not a shell builtin -or there is an error loading a new builtin from a shared object. -</P><P> - -<DT><CODE>help</CODE> -<DD><A NAME="IDX97"></A> -<TABLE><tr><td> </td><td class=example><pre>help [-s] [<VAR>pattern</VAR>] -</pre></td></tr></table>Display helpful information about builtin commands. -If <VAR>pattern</VAR> is specified, <CODE>help</CODE> gives detailed help -on all commands matching <VAR>pattern</VAR>, otherwise a list of -the builtins is printed. -The <SAMP>`-s'</SAMP> option restricts the information displayed to a short -usage synopsis. -The return status is zero unless no command matches <VAR>pattern</VAR>. -<P> - -<DT><CODE>let</CODE> -<DD><A NAME="IDX98"></A> -<TABLE><tr><td> </td><td class=example><pre>let <VAR>expression</VAR> [<VAR>expression</VAR>] -</pre></td></tr></table>The <CODE>let</CODE> builtin allows arithmetic to be performed on shell -variables. Each <VAR>expression</VAR> is evaluated according to the -rules given below in <A HREF="b.html#SEC81">6.5 Shell Arithmetic</A>. If the -last <VAR>expression</VAR> evaluates to 0, <CODE>let</CODE> returns 1; -otherwise 0 is returned. -<P> - -<DT><CODE>local</CODE> -<DD><A NAME="IDX99"></A> -<TABLE><tr><td> </td><td class=example><pre>local [<VAR>option</VAR>] <VAR>name</VAR>[=<VAR>value</VAR>] <small>...</small> -</pre></td></tr></table>For each argument, a local variable named <VAR>name</VAR> is created, -and assigned <VAR>value</VAR>. -The <VAR>option</VAR> can be any of the options accepted by <CODE>declare</CODE>. -<CODE>local</CODE> can only be used within a function; it makes the variable -<VAR>name</VAR> have a visible scope restricted to that function and its -children. The return status is zero unless <CODE>local</CODE> is used outside -a function, an invalid <VAR>name</VAR> is supplied, or <VAR>name</VAR> is a -readonly variable. -<P> - -<DT><CODE>logout</CODE> -<DD><A NAME="IDX100"></A> -<TABLE><tr><td> </td><td class=example><pre>logout [<VAR>n</VAR>] -</pre></td></tr></table>Exit a login shell, returning a status of <VAR>n</VAR> to the shell's -parent. -<P> - -<DT><CODE>printf</CODE> -<DD><A NAME="IDX101"></A> -<TABLE><tr><td> </td><td class=example><pre><CODE>printf</CODE> [-v <VAR>var</VAR>] <VAR>format</VAR> [<VAR>arguments</VAR>] -</pre></td></tr></table>Write the formatted <VAR>arguments</VAR> to the standard output under the -control of the <VAR>format</VAR>. -The <VAR>format</VAR> is a character string which contains three types of objects: -plain characters, which are simply copied to standard output, character -escape sequences, which are converted and copied to the standard output, and -format specifications, each of which causes printing of the next successive -<VAR>argument</VAR>. -In addition to the standard <CODE>printf(1)</CODE> formats, <SAMP>`%b'</SAMP> causes -<CODE>printf</CODE> to expand backslash escape sequences in the corresponding -<VAR>argument</VAR>, -(except that <SAMP>`\c'</SAMP> terminates output, backslashes in -<SAMP>`\''</SAMP>, <SAMP>`\"'</SAMP>, and <SAMP>`\?'</SAMP> are not removed, and octal escapes -beginning with <SAMP>`\0'</SAMP> may contain up to four digits), -and <SAMP>`%q'</SAMP> causes <CODE>printf</CODE> to output the -corresponding <VAR>argument</VAR> in a format that can be reused as shell input. -<P> - -The <SAMP>`-v'</SAMP> option causes the output to be assigned to the variable -<VAR>var</VAR> rather than being printed to the standard output. -</P><P> - -The <VAR>format</VAR> is reused as necessary to consume all of the <VAR>arguments</VAR>. -If the <VAR>format</VAR> requires more <VAR>arguments</VAR> than are supplied, the -extra format specifications behave as if a zero value or null string, as -appropriate, had been supplied. The return value is zero on success, -non-zero on failure. -</P><P> - -<DT><CODE>read</CODE> -<DD><A NAME="IDX102"></A> -<TABLE><tr><td> </td><td class=example><pre>read [-ers] [-a <VAR>aname</VAR>] [-d <VAR>delim</VAR>] [-n <VAR>nchars</VAR>] [-p <VAR>prompt</VAR>] [-t <VAR>timeout</VAR>] [-u <VAR>fd</VAR>] [<VAR>name</VAR> <small>...</small>] -</pre></td></tr></table>One line is read from the standard input, or from the file descriptor -<VAR>fd</VAR> supplied as an argument to the <SAMP>`-u'</SAMP> option, and the first word -is assigned to the first <VAR>name</VAR>, the second word to the second <VAR>name</VAR>, -and so on, with leftover words and their intervening separators assigned -to the last <VAR>name</VAR>. -If there are fewer words read from the input stream than names, -the remaining names are assigned empty values. -The characters in the value of the <CODE>IFS</CODE> variable -are used to split the line into words. -The backslash character <SAMP>`\'</SAMP> may be used to remove any special -meaning for the next character read and for line continuation. -If no names are supplied, the line read is assigned to the -variable <CODE>REPLY</CODE>. -The return code is zero, unless end-of-file is encountered, <CODE>read</CODE> -times out, or an invalid file descriptor is supplied as the argument to -<SAMP>`-u'</SAMP>. -Options, if supplied, have the following meanings: -<P> - -<DL COMPACT> -<DT><CODE>-a <VAR>aname</VAR></CODE> -<DD>The words are assigned to sequential indices of the array variable -<VAR>aname</VAR>, starting at 0. -All elements are removed from <VAR>aname</VAR> before the assignment. -Other <VAR>name</VAR> arguments are ignored. -<P> - -<DT><CODE>-d <VAR>delim</VAR></CODE> -<DD>The first character of <VAR>delim</VAR> is used to terminate the input line, -rather than newline. -<P> - -<DT><CODE>-e</CODE> -<DD>Readline (see section <A HREF="b.html#SEC93">8. Command Line Editing</A>) is used to obtain the line. -<P> - -<DT><CODE>-n <VAR>nchars</VAR></CODE> -<DD><CODE>read</CODE> returns after reading <VAR>nchars</VAR> characters rather than -waiting for a complete line of input. -<P> - -<DT><CODE>-p <VAR>prompt</VAR></CODE> -<DD>Display <VAR>prompt</VAR>, without a trailing newline, before attempting -to read any input. -The prompt is displayed only if input is coming from a terminal. -<P> - -<DT><CODE>-r</CODE> -<DD>If this option is given, backslash does not act as an escape character. -The backslash is considered to be part of the line. -In particular, a backslash-newline pair may not be used as a line -continuation. -<P> - -<DT><CODE>-s</CODE> -<DD>Silent mode. If input is coming from a terminal, characters are -not echoed. -<P> - -<DT><CODE>-t <VAR>timeout</VAR></CODE> -<DD>Cause <CODE>read</CODE> to time out and return failure if a complete line of -input is not read within <VAR>timeout</VAR> seconds. -This option has no effect if <CODE>read</CODE> is not reading input from the -terminal or a pipe. -<P> - -<DT><CODE>-u <VAR>fd</VAR></CODE> -<DD>Read input from file descriptor <VAR>fd</VAR>. -<P> - -</DL> -<P> - -<DT><CODE>source</CODE> -<DD><A NAME="IDX103"></A> -<TABLE><tr><td> </td><td class=example><pre>source <VAR>filename</VAR> -</pre></td></tr></table>A synonym for <CODE>.</CODE> (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -<P> - -<DT><CODE>type</CODE> -<DD><A NAME="IDX104"></A> -<TABLE><tr><td> </td><td class=example><pre>type [-afptP] [<VAR>name</VAR> <small>...</small>] -</pre></td></tr></table>For each <VAR>name</VAR>, indicate how it would be interpreted if used as a -command name. -<P> - -If the <SAMP>`-t'</SAMP> option is used, <CODE>type</CODE> prints a single word -which is one of <SAMP>`alias'</SAMP>, <SAMP>`function'</SAMP>, <SAMP>`builtin'</SAMP>, -<SAMP>`file'</SAMP> or <SAMP>`keyword'</SAMP>, -if <VAR>name</VAR> is an alias, shell function, shell builtin, -disk file, or shell reserved word, respectively. -If the <VAR>name</VAR> is not found, then nothing is printed, and -<CODE>type</CODE> returns a failure status. -</P><P> - -If the <SAMP>`-p'</SAMP> option is used, <CODE>type</CODE> either returns the name -of the disk file that would be executed, or nothing if <SAMP>`-t'</SAMP> -would not return <SAMP>`file'</SAMP>. -</P><P> - -The <SAMP>`-P'</SAMP> option forces a path search for each <VAR>name</VAR>, even if -<SAMP>`-t'</SAMP> would not return <SAMP>`file'</SAMP>. -</P><P> - -If a command is hashed, <SAMP>`-p'</SAMP> and <SAMP>`-P'</SAMP> print the hashed value, -not necessarily the file that appears first in <CODE>$PATH</CODE>. -</P><P> - -If the <SAMP>`-a'</SAMP> option is used, <CODE>type</CODE> returns all of the places -that contain an executable named <VAR>file</VAR>. -This includes aliases and functions, if and only if the <SAMP>`-p'</SAMP> option -is not also used. -</P><P> - -If the <SAMP>`-f'</SAMP> option is used, <CODE>type</CODE> does not attempt to find -shell functions, as with the <CODE>command</CODE> builtin. -</P><P> - -The return status is zero if any of the <VAR>names</VAR> are found, non-zero -if none are found. -</P><P> - -<DT><CODE>typeset</CODE> -<DD><A NAME="IDX105"></A> -<TABLE><tr><td> </td><td class=example><pre>typeset [-afFrxi] [-p] [<VAR>name</VAR>[=<VAR>value</VAR>] <small>...</small>] -</pre></td></tr></table>The <CODE>typeset</CODE> command is supplied for compatibility with the Korn -shell; however, it has been deprecated in favor of the <CODE>declare</CODE> -builtin command. -<P> - -<DT><CODE>ulimit</CODE> -<DD><A NAME="IDX106"></A> -<TABLE><tr><td> </td><td class=example><pre>ulimit [-acdefilmnpqrstuvxSH] [<VAR>limit</VAR>] -</pre></td></tr></table><CODE>ulimit</CODE> provides control over the resources available to processes -started by the shell, on systems that allow such control. If an -option is given, it is interpreted as follows: -<DL COMPACT> -<DT><CODE>-S</CODE> -<DD>Change and report the soft limit associated with a resource. -<P> - -<DT><CODE>-H</CODE> -<DD>Change and report the hard limit associated with a resource. -<P> - -<DT><CODE>-a</CODE> -<DD>All current limits are reported. -<P> - -<DT><CODE>-c</CODE> -<DD>The maximum size of core files created. -<P> - -<DT><CODE>-d</CODE> -<DD>The maximum size of a process's data segment. -<P> - -<DT><CODE>-e</CODE> -<DD>The maximum scheduling priority ("nice"). -<P> - -<DT><CODE>-f</CODE> -<DD>The maximum size of files written by the shell and its children. -<P> - -<DT><CODE>-i</CODE> -<DD>The maximum number of pending signals. -<P> - -<DT><CODE>-l</CODE> -<DD>The maximum size that may be locked into memory. -<P> - -<DT><CODE>-m</CODE> -<DD>The maximum resident set size. -<P> - -<DT><CODE>-n</CODE> -<DD>The maximum number of open file descriptors. -<P> - -<DT><CODE>-p</CODE> -<DD>The pipe buffer size. -<P> - -<DT><CODE>-q</CODE> -<DD>The maximum number of bytes in POSIX message queues. -<P> - -<DT><CODE>-r</CODE> -<DD>The maximum real-time scheduling priority. -<P> - -<DT><CODE>-s</CODE> -<DD>The maximum stack size. -<P> - -<DT><CODE>-t</CODE> -<DD>The maximum amount of cpu time in seconds. -<P> - -<DT><CODE>-u</CODE> -<DD>The maximum number of processes available to a single user. -<P> - -<DT><CODE>-v</CODE> -<DD>The maximum amount of virtual memory available to the process. -<P> - -<DT><CODE>-x</CODE> -<DD>The maximum number of file locks. -<P> - -</DL> -<P> - -If <VAR>limit</VAR> is given, it is the new value of the specified resource; -the special <VAR>limit</VAR> values <CODE>hard</CODE>, <CODE>soft</CODE>, and -<CODE>unlimited</CODE> stand for the current hard limit, the current soft limit, -and no limit, respectively. -Otherwise, the current value of the soft limit for the specified resource -is printed, unless the <SAMP>`-H'</SAMP> option is supplied. -When setting new limits, if neither <SAMP>`-H'</SAMP> nor <SAMP>`-S'</SAMP> is supplied, -both the hard and soft limits are set. -If no option is given, then <SAMP>`-f'</SAMP> is assumed. Values are in 1024-byte -increments, except for <SAMP>`-t'</SAMP>, which is in seconds, <SAMP>`-p'</SAMP>, -which is in units of 512-byte blocks, and <SAMP>`-n'</SAMP> and <SAMP>`-u'</SAMP>, which -are unscaled values. -</P><P> - -The return status is zero unless an invalid option or argument is supplied, -or an error occurs while setting a new limit. -</P><P> - -<DT><CODE>unalias</CODE> -<DD><A NAME="IDX107"></A> -<TABLE><tr><td> </td><td class=example><pre>unalias [-a] [<VAR>name</VAR> <small>...</small> ] -</pre></td></tr></table><P> - -Remove each <VAR>name</VAR> from the list of aliases. If <SAMP>`-a'</SAMP> is -supplied, all aliases are removed. -Aliases are described in <A HREF="b.html#SEC82">6.6 Aliases</A>. -</P><P> - -</DL> -<P> - -<A NAME="Modifying Shell Behavior"></A> -<HR SIZE="6"> -<A NAME="SEC59"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC58"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC60"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 4.3 Modifying Shell Behavior </H2> -<!--docid::SEC59::--> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC60">4.3.1 The Set Builtin</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Change the values of shell attributes and - positional parameters.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Modify shell optional behavior.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="The Set Builtin"></A> -<HR SIZE="6"> -<A NAME="SEC60"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC59"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC61"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC59"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 4.3.1 The Set Builtin </H3> -<!--docid::SEC60::--> -<P> - -This builtin is so complicated that it deserves its own section. <CODE>set</CODE> -allows you to change the values of shell options and set the positional -parameters, or to display the names and values of shell variables. -</P><P> - -<DL COMPACT> -<DT><CODE>set</CODE> -<DD><A NAME="IDX108"></A> -<TABLE><tr><td> </td><td class=example><pre>set [--abefhkmnptuvxBCEHPT] [-o <VAR>option</VAR>] [<VAR>argument</VAR> <small>...</small>] -set [+abefhkmnptuvxBCEHPT] [+o <VAR>option</VAR>] [<VAR>argument</VAR> <small>...</small>] -</pre></td></tr></table><P> - -If no options or arguments are supplied, <CODE>set</CODE> displays the names -and values of all shell variables and functions, sorted according to the -current locale, in a format that may be reused as input -for setting or resetting the currently-set variables. -Read-only variables cannot be reset. -In POSIX mode, only shell variables are listed. -</P><P> - -When options are supplied, they set or unset shell attributes. -Options, if specified, have the following meanings: -</P><P> - -<DL COMPACT> -<DT><CODE>-a</CODE> -<DD>Mark variables and function which are modified or created for export -to the environment of subsequent commands. -<P> - -<DT><CODE>-b</CODE> -<DD>Cause the status of terminated background jobs to be reported -immediately, rather than before printing the next primary prompt. -<P> - -<DT><CODE>-e</CODE> -<DD>Exit immediately if a simple command (see section <A HREF="b.html#SEC16">3.2.1 Simple Commands</A>) exits -with a non-zero status, unless the command that fails is part of the -command list immediately following a <CODE>while</CODE> or <CODE>until</CODE> keyword, -part of the test in an <CODE>if</CODE> statement, -part of a <CODE>&&</CODE> or <CODE>||</CODE> list, -any command in a pipeline but the last, -or if the command's return status is being inverted using <CODE>!</CODE>. -A trap on <CODE>ERR</CODE>, if set, is executed before the shell exits. -<P> - -<DT><CODE>-f</CODE> -<DD>Disable file name generation (globbing). -<P> - -<DT><CODE>-h</CODE> -<DD>Locate and remember (hash) commands as they are looked up for execution. -This option is enabled by default. -<P> - -<DT><CODE>-k</CODE> -<DD>All arguments in the form of assignment statements are placed -in the environment for a command, not just those that precede -the command name. -<P> - -<DT><CODE>-m</CODE> -<DD>Job control is enabled (see section <A HREF="b.html#SEC89">7. Job Control</A>). -<P> - -<DT><CODE>-n</CODE> -<DD>Read commands but do not execute them; this may be used to check a -script for syntax errors. -This option is ignored by interactive shells. -<P> - -<DT><CODE>-o <VAR>option-name</VAR></CODE> -<DD><P> - -Set the option corresponding to <VAR>option-name</VAR>: -</P><P> - -<DL COMPACT> -<DT><CODE>allexport</CODE> -<DD>Same as <CODE>-a</CODE>. -<P> - -<DT><CODE>braceexpand</CODE> -<DD>Same as <CODE>-B</CODE>. -<P> - -<DT><CODE>emacs</CODE> -<DD>Use an <CODE>emacs</CODE>-style line editing interface (see section <A HREF="b.html#SEC93">8. Command Line Editing</A>). -<P> - -<DT><CODE>errexit</CODE> -<DD>Same as <CODE>-e</CODE>. -<P> - -<DT><CODE>errtrace</CODE> -<DD>Same as <CODE>-E</CODE>. -<P> - -<DT><CODE>functrace</CODE> -<DD>Same as <CODE>-T</CODE>. -<P> - -<DT><CODE>hashall</CODE> -<DD>Same as <CODE>-h</CODE>. -<P> - -<DT><CODE>histexpand</CODE> -<DD>Same as <CODE>-H</CODE>. -<P> - -<DT><CODE>history</CODE> -<DD>Enable command history, as described in <A HREF="b.html#SEC118">9.1 Bash History Facilities</A>. -This option is on by default in interactive shells. -<P> - -<DT><CODE>ignoreeof</CODE> -<DD>An interactive shell will not exit upon reading EOF. -<P> - -<DT><CODE>keyword</CODE> -<DD>Same as <CODE>-k</CODE>. -<P> - -<DT><CODE>monitor</CODE> -<DD>Same as <CODE>-m</CODE>. -<P> - -<DT><CODE>noclobber</CODE> -<DD>Same as <CODE>-C</CODE>. -<P> - -<DT><CODE>noexec</CODE> -<DD>Same as <CODE>-n</CODE>. -<P> - -<DT><CODE>noglob</CODE> -<DD>Same as <CODE>-f</CODE>. -<P> - -<DT><CODE>nolog</CODE> -<DD>Currently ignored. -<P> - -<DT><CODE>notify</CODE> -<DD>Same as <CODE>-b</CODE>. -<P> - -<DT><CODE>nounset</CODE> -<DD>Same as <CODE>-u</CODE>. -<P> - -<DT><CODE>onecmd</CODE> -<DD>Same as <CODE>-t</CODE>. -<P> - -<DT><CODE>physical</CODE> -<DD>Same as <CODE>-P</CODE>. -<P> - -<DT><CODE>pipefail</CODE> -<DD>If set, the return value of a pipeline is the value of the last -(rightmost) command to exit with a non-zero status, or zero if all -commands in the pipeline exit successfully. -This option is disabled by default. -<P> - -<DT><CODE>posix</CODE> -<DD>Change the behavior of Bash where the default operation differs -from the POSIX standard to match the standard -(see section <A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A>). -This is intended to make Bash behave as a strict superset of that -standard. -<P> - -<DT><CODE>privileged</CODE> -<DD>Same as <CODE>-p</CODE>. -<P> - -<DT><CODE>verbose</CODE> -<DD>Same as <CODE>-v</CODE>. -<P> - -<DT><CODE>vi</CODE> -<DD>Use a <CODE>vi</CODE>-style line editing interface. -<P> - -<DT><CODE>xtrace</CODE> -<DD>Same as <CODE>-x</CODE>. -</DL> -<P> - -<DT><CODE>-p</CODE> -<DD>Turn on privileged mode. -In this mode, the <CODE>$BASH_ENV</CODE> and <CODE>$ENV</CODE> files are not -processed, shell functions are not inherited from the environment, -and the <CODE>SHELLOPTS</CODE> variable, if it appears in the environment, -is ignored. -If the shell is started with the effective user (group) id not equal to the -real user (group) id, and the <CODE>-p</CODE> option is not supplied, these actions -are taken and the effective user id is set to the real user id. -If the <CODE>-p</CODE> option is supplied at startup, the effective user id is -not reset. -Turning this option off causes the effective user -and group ids to be set to the real user and group ids. -<P> - -<DT><CODE>-t</CODE> -<DD>Exit after reading and executing one command. -<P> - -<DT><CODE>-u</CODE> -<DD>Treat unset variables as an error when performing parameter expansion. -An error message will be written to the standard error, and a non-interactive -shell will exit. -<P> - -<DT><CODE>-v</CODE> -<DD>Print shell input lines as they are read. -<P> - -<DT><CODE>-x</CODE> -<DD>Print a trace of simple commands, <CODE>for</CODE> commands, <CODE>case</CODE> -commands, <CODE>select</CODE> commands, and arithmetic <CODE>for</CODE> commands -and their arguments or associated word lists after they are -expanded and before they are executed. The value of the <CODE>PS4</CODE> -variable is expanded and the resultant value is printed before -the command and its expanded arguments. -<P> - -<DT><CODE>-B</CODE> -<DD>The shell will perform brace expansion (see section <A HREF="b.html#SEC28">3.5.1 Brace Expansion</A>). -This option is on by default. -<P> - -<DT><CODE>-C</CODE> -<DD>Prevent output redirection using <SAMP>`>'</SAMP>, <SAMP>`>&'</SAMP>, and <SAMP>`<>'</SAMP> -from overwriting existing files. -<P> - -<DT><CODE>-E</CODE> -<DD>If set, any trap on <CODE>ERR</CODE> is inherited by shell functions, command -substitutions, and commands executed in a subshell environment. -The <CODE>ERR</CODE> trap is normally not inherited in such cases. -<P> - -<DT><CODE>-H</CODE> -<DD>Enable <SAMP>`!'</SAMP> style history substitution (see section <A HREF="b.html#SEC120">9.3 History Expansion</A>). -This option is on by default for interactive shells. -<P> - -<DT><CODE>-P</CODE> -<DD>If set, do not follow symbolic links when performing commands such as -<CODE>cd</CODE> which change the current directory. The physical directory -is used instead. By default, Bash follows -the logical chain of directories when performing commands -which change the current directory. -<P> - -For example, if <TT>`/usr/sys'</TT> is a symbolic link to <TT>`/usr/local/sys'</TT> -then: -<TABLE><tr><td> </td><td class=example><pre>$ cd /usr/sys; echo $PWD -/usr/sys -$ cd ..; pwd -/usr -</pre></td></tr></table></P><P> - -If <CODE>set -P</CODE> is on, then: -<TABLE><tr><td> </td><td class=example><pre>$ cd /usr/sys; echo $PWD -/usr/local/sys -$ cd ..; pwd -/usr/local -</pre></td></tr></table></P><P> - -<DT><CODE>-T</CODE> -<DD>If set, any trap on <CODE>DEBUG</CODE> and <CODE>RETURN</CODE> are inherited by -shell functions, command substitutions, and commands executed -in a subshell environment. -The <CODE>DEBUG</CODE> and <CODE>RETURN</CODE> traps are normally not inherited -in such cases. -<P> - -<DT><CODE>--</CODE> -<DD>If no arguments follow this option, then the positional parameters are -unset. Otherwise, the positional parameters are set to the -<VAR>arguments</VAR>, even if some of them begin with a <SAMP>`-'</SAMP>. -<P> - -<DT><CODE>-</CODE> -<DD>Signal the end of options, cause all remaining <VAR>arguments</VAR> -to be assigned to the positional parameters. The <SAMP>`-x'</SAMP> -and <SAMP>`-v'</SAMP> options are turned off. -If there are no arguments, the positional parameters remain unchanged. -</DL> -<P> - -Using <SAMP>`+'</SAMP> rather than <SAMP>`-'</SAMP> causes these options to be -turned off. The options can also be used upon invocation of the -shell. The current set of options may be found in <CODE>$-</CODE>. -</P><P> - -The remaining N <VAR>arguments</VAR> are positional parameters and are -assigned, in order, to <CODE>$1</CODE>, <CODE>$2</CODE>, <small>...</small> <CODE>$N</CODE>. -The special parameter <CODE>#</CODE> is set to N. -</P><P> - -The return status is always zero unless an invalid option is supplied. -</DL> -<P> - -<A NAME="The Shopt Builtin"></A> -<HR SIZE="6"> -<A NAME="SEC61"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC60"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC59"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 4.3.2 The Shopt Builtin </H3> -<!--docid::SEC61::--> -<P> - -This builtin allows you to change additional shell optional behavior. -</P><P> - -<DL COMPACT> - -<DT><CODE>shopt</CODE> -<DD><A NAME="IDX109"></A> -<TABLE><tr><td> </td><td class=example><pre>shopt [-pqsu] [-o] [<VAR>optname</VAR> <small>...</small>] -</pre></td></tr></table>Toggle the values of variables controlling optional shell behavior. -With no options, or with the <SAMP>`-p'</SAMP> option, a list of all settable -options is displayed, with an indication of whether or not each is set. -The <SAMP>`-p'</SAMP> option causes output to be displayed in a form that -may be reused as input. -Other options have the following meanings: -<P> - -<DL COMPACT> -<DT><CODE>-s</CODE> -<DD>Enable (set) each <VAR>optname</VAR>. -<P> - -<DT><CODE>-u</CODE> -<DD>Disable (unset) each <VAR>optname</VAR>. -<P> - -<DT><CODE>-q</CODE> -<DD>Suppresses normal output; the return status -indicates whether the <VAR>optname</VAR> is set or unset. -If multiple <VAR>optname</VAR> arguments are given with <SAMP>`-q'</SAMP>, -the return status is zero if all <VAR>optnames</VAR> are enabled; -non-zero otherwise. -<P> - -<DT><CODE>-o</CODE> -<DD>Restricts the values of -<VAR>optname</VAR> to be those defined for the <SAMP>`-o'</SAMP> option to the -<CODE>set</CODE> builtin (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -</DL> -<P> - -If either <SAMP>`-s'</SAMP> or <SAMP>`-u'</SAMP> -is used with no <VAR>optname</VAR> arguments, the display is limited to -those options which are set or unset, respectively. -</P><P> - -Unless otherwise noted, the <CODE>shopt</CODE> options are disabled (off) -by default. -</P><P> - -The return status when listing options is zero if all <VAR>optnames</VAR> -are enabled, non-zero otherwise. When setting or unsetting options, -the return status is zero unless an <VAR>optname</VAR> is not a valid shell -option. -</P><P> - -The list of <CODE>shopt</CODE> options is: -<DL COMPACT> - -<DT><CODE>autocd</CODE> -<DD>If set, a command name that is the name of a directory is executed as if -it were the argument to the <CODE>cd</CODE> command. -This option is only used by interactive shells. -<P> - -<DT><CODE>cdable_vars</CODE> -<DD>If this is set, an argument to the <CODE>cd</CODE> builtin command that -is not a directory is assumed to be the name of a variable whose -value is the directory to change to. -<P> - -<DT><CODE>cdspell</CODE> -<DD>If set, minor errors in the spelling of a directory component in a -<CODE>cd</CODE> command will be corrected. -The errors checked for are transposed characters, -a missing character, and a character too many. -If a correction is found, the corrected path is printed, -and the command proceeds. -This option is only used by interactive shells. -<P> - -<DT><CODE>checkhash</CODE> -<DD>If this is set, Bash checks that a command found in the hash -table exists before trying to execute it. If a hashed command no -longer exists, a normal path search is performed. -<P> - -<DT><CODE>checkjobs</CODE> -<DD>If set, Bash lists the status of any stopped and running jobs before -exiting an interactive shell. If any jobs are running, this causes -the exit to be deferred until a second exit is attempted without an -intervening command (see section <A HREF="b.html#SEC89">7. Job Control</A>). -The shell always postpones exiting if any jobs are stopped. -<P> - -<DT><CODE>checkwinsize</CODE> -<DD>If set, Bash checks the window size after each command -and, if necessary, updates the values of -<CODE>LINES</CODE> and <CODE>COLUMNS</CODE>. -<P> - -<DT><CODE>cmdhist</CODE> -<DD>If set, Bash -attempts to save all lines of a multiple-line -command in the same history entry. This allows -easy re-editing of multi-line commands. -<P> - -<DT><CODE>dotglob</CODE> -<DD>If set, Bash includes filenames beginning with a `.' in -the results of filename expansion. -<P> - -<DT><CODE>execfail</CODE> -<DD>If this is set, a non-interactive shell will not exit if -it cannot execute the file specified as an argument to the <CODE>exec</CODE> -builtin command. An interactive shell does not exit if <CODE>exec</CODE> -fails. -<P> - -<DT><CODE>expand_aliases</CODE> -<DD>If set, aliases are expanded as described below under Aliases, -<A HREF="b.html#SEC82">6.6 Aliases</A>. -This option is enabled by default for interactive shells. -<P> - -<DT><CODE>extdebug</CODE> -<DD>If set, behavior intended for use by debuggers is enabled: -<P> - -<OL> -<LI> -The <SAMP>`-F'</SAMP> option to the <CODE>declare</CODE> builtin (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>) -displays the source file name and line number corresponding to each function -name supplied as an argument. -<P> - -<LI> -If the command run by the <CODE>DEBUG</CODE> trap returns a non-zero value, the -next command is skipped and not executed. -<P> - -<LI> -If the command run by the <CODE>DEBUG</CODE> trap returns a value of 2, and the -shell is executing in a subroutine (a shell function or a shell script -executed by the <CODE>.</CODE> or <CODE>source</CODE> builtins), a call to -<CODE>return</CODE> is simulated. -<P> - -<LI> -<CODE>BASH_ARGC</CODE> and <CODE>BASH_ARGV</CODE> are updated as described in their -descriptions (see section <A HREF="b.html#SEC65">5.2 Bash Variables</A>). -<P> - -<LI> -Function tracing is enabled: command substitution, shell functions, and -subshells invoked with <CODE>( <VAR>command</VAR> )</CODE> inherit the -<CODE>DEBUG</CODE> and <CODE>RETURN</CODE> traps. -<P> - -<LI> -Error tracing is enabled: command substitution, shell functions, and -subshells invoked with <CODE>( <VAR>command</VAR> )</CODE> inherit the -<CODE>ERROR</CODE> trap. -</OL> -<P> - -<DT><CODE>extglob</CODE> -<DD>If set, the extended pattern matching features described above -(see section <A HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A>) are enabled. -<P> - -<DT><CODE>extquote</CODE> -<DD>If set, <CODE>$'<VAR>string</VAR>'</CODE> and <CODE>$"<VAR>string</VAR>"</CODE> quoting is -performed within <CODE>${<VAR>parameter</VAR>}</CODE> expansions -enclosed in double quotes. This option is enabled by default. -<P> - -<DT><CODE>failglob</CODE> -<DD>If set, patterns which fail to match filenames during pathname expansion -result in an expansion error. -<P> - -<DT><CODE>force_fignore</CODE> -<DD>If set, the suffixes specified by the <CODE>FIGNORE</CODE> shell variable -cause words to be ignored when performing word completion even if -the ignored words are the only possible completions. -See section <A HREF="b.html#SEC65">5.2 Bash Variables</A>, for a description of <CODE>FIGNORE</CODE>. -This option is enabled by default. -<P> - -<DT><CODE>gnu_errfmt</CODE> -<DD>If set, shell error messages are written in the standard GNU error -message format. -<P> - -<DT><CODE>histappend</CODE> -<DD>If set, the history list is appended to the file named by the value -of the <CODE>HISTFILE</CODE> -variable when the shell exits, rather than overwriting the file. -<P> - -<DT><CODE>histreedit</CODE> -<DD>If set, and Readline -is being used, a user is given the opportunity to re-edit a -failed history substitution. -<P> - -<DT><CODE>histverify</CODE> -<DD>If set, and Readline -is being used, the results of history substitution are not immediately -passed to the shell parser. Instead, the resulting line is loaded into -the Readline editing buffer, allowing further modification. -<P> - -<DT><CODE>hostcomplete</CODE> -<DD>If set, and Readline is being used, Bash will attempt to perform -hostname completion when a word containing a <SAMP>`@'</SAMP> is being -completed (see section <A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A>). This option is enabled -by default. -<P> - -<DT><CODE>huponexit</CODE> -<DD>If set, Bash will send <CODE>SIGHUP</CODE> to all jobs when an interactive -login shell exits (see section <A HREF="b.html#SEC54">3.7.6 Signals</A>). -<P> - -<DT><CODE>interactive_comments</CODE> -<DD>Allow a word beginning with <SAMP>`#'</SAMP> -to cause that word and all remaining characters on that -line to be ignored in an interactive shell. -This option is enabled by default. -<P> - -<DT><CODE>lithist</CODE> -<DD>If enabled, and the <CODE>cmdhist</CODE> -option is enabled, multi-line commands are saved to the history with -embedded newlines rather than using semicolon separators where possible. -<P> - -<DT><CODE>login_shell</CODE> -<DD>The shell sets this option if it is started as a login shell -(see section <A HREF="b.html#SEC67">6.1 Invoking Bash</A>). -The value may not be changed. -<P> - -<DT><CODE>mailwarn</CODE> -<DD>If set, and a file that Bash is checking for mail has been -accessed since the last time it was checked, the message -<CODE>"The mail in <VAR>mailfile</VAR> has been read"</CODE> is displayed. -<P> - -<DT><CODE>no_empty_cmd_completion</CODE> -<DD>If set, and Readline is being used, Bash will not attempt to search -the <CODE>PATH</CODE> for possible completions when completion is attempted -on an empty line. -<P> - -<DT><CODE>nocaseglob</CODE> -<DD>If set, Bash matches filenames in a case-insensitive fashion when -performing filename expansion. -<P> - -<DT><CODE>nocasematch</CODE> -<DD>If set, Bash matches patterns in a case-insensitive fashion when -performing matching while executing <CODE>case</CODE> or <CODE>[[</CODE> -conditional commands. -<P> - -<DT><CODE>nullglob</CODE> -<DD>If set, Bash allows filename patterns which match no -files to expand to a null string, rather than themselves. -<P> - -<DT><CODE>progcomp</CODE> -<DD>If set, the programmable completion facilities -(see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>) are enabled. -This option is enabled by default. -<P> - -<DT><CODE>promptvars</CODE> -<DD>If set, prompt strings undergo -parameter expansion, command substitution, arithmetic -expansion, and quote removal after being expanded -as described below (see section <A HREF="b.html#SEC86">6.9 Controlling the Prompt</A>). -This option is enabled by default. -<P> - -<DT><CODE>restricted_shell</CODE> -<DD>The shell sets this option if it is started in restricted mode -(see section <A HREF="b.html#SEC87">6.10 The Restricted Shell</A>). -The value may not be changed. -This is not reset when the startup files are executed, allowing -the startup files to discover whether or not a shell is restricted. -<P> - -<DT><CODE>shift_verbose</CODE> -<DD>If this is set, the <CODE>shift</CODE> -builtin prints an error message when the shift count exceeds the -number of positional parameters. -<P> - -<DT><CODE>sourcepath</CODE> -<DD>If set, the <CODE>source</CODE> builtin uses the value of <CODE>PATH</CODE> -to find the directory containing the file supplied as an argument. -This option is enabled by default. -<P> - -<DT><CODE>xpg_echo</CODE> -<DD>If set, the <CODE>echo</CODE> builtin expands backslash-escape sequences -by default. -<P> - -</DL> -<P> - -The return status when listing options is zero if all <VAR>optnames</VAR> -are enabled, non-zero otherwise. -When setting or unsetting options, the return status is zero unless an -<VAR>optname</VAR> is not a valid shell option. -</P><P> - -</DL> -<P> - -<A NAME="Special Builtins"></A> -<HR SIZE="6"> -<A NAME="SEC62"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC61"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC56"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 4.4 Special Builtins </H2> -<!--docid::SEC62::--> -<P> - -For historical reasons, the POSIX standard has classified -several builtin commands as <EM>special</EM>. -When Bash is executing in POSIX mode, the special builtins -differ from other builtin commands in three respects: -</P><P> - -<OL> -<LI> -Special builtins are found before shell functions during command lookup. -<P> - -<LI> -If a special builtin returns an error status, a non-interactive shell exits. -<P> - -<LI> -Assignment statements preceding the command stay in effect in the shell -environment after the command completes. -</OL> -<P> - -When Bash is not executing in POSIX mode, these builtins behave no -differently than the rest of the Bash builtin commands. -The Bash POSIX mode is described in <A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A>. -</P><P> - -These are the POSIX special builtins: -<TABLE><tr><td> </td><td class=example><pre>break : . continue eval exec exit export readonly return set -shift trap unset -</pre></td></tr></table></P><P> - -<A NAME="Shell Variables"></A> -<HR SIZE="6"> -<A NAME="SEC63"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC62"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC64"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 5. Shell Variables </H1> -<!--docid::SEC63::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Variables which Bash uses in the same way - as the Bourne Shell.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">List of variables that exist in Bash.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -This chapter describes the shell variables that Bash uses. -Bash automatically assigns default values to a number of variables. -</P><P> - -<A NAME="Bourne Shell Variables"></A> -<HR SIZE="6"> -<A NAME="SEC64"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC65"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 5.1 Bourne Shell Variables </H2> -<!--docid::SEC64::--> -<P> - -Bash uses certain shell variables in the same way as the Bourne shell. -In some cases, Bash assigns a default value to the variable. -</P><P> - -<DL COMPACT> - -<A NAME="IDX110"></A> -<DT><CODE>CDPATH</CODE> -<DD><A NAME="IDX111"></A> -A colon-separated list of directories used as a search path for -the <CODE>cd</CODE> builtin command. -<P> - -<A NAME="IDX112"></A> -<DT><CODE>HOME</CODE> -<DD><A NAME="IDX113"></A> -The current user's home directory; the default for the <CODE>cd</CODE> builtin -command. -The value of this variable is also used by tilde expansion -(see section <A HREF="b.html#SEC29">3.5.2 Tilde Expansion</A>). -<P> - -<A NAME="IDX114"></A> -<DT><CODE>IFS</CODE> -<DD><A NAME="IDX115"></A> -A list of characters that separate fields; used when the shell splits -words as part of expansion. -<P> - -<A NAME="IDX116"></A> -<DT><CODE>MAIL</CODE> -<DD><A NAME="IDX117"></A> -If this parameter is set to a filename and the <CODE>MAILPATH</CODE> variable -is not set, Bash informs the user of the arrival of mail in -the specified file. -<P> - -<A NAME="IDX118"></A> -<DT><CODE>MAILPATH</CODE> -<DD><A NAME="IDX119"></A> -A colon-separated list of filenames which the shell periodically checks -for new mail. -Each list entry can specify the message that is printed when new mail -arrives in the mail file by separating the file name from the message with -a <SAMP>`?'</SAMP>. -When used in the text of the message, <CODE>$_</CODE> expands to the name of -the current mail file. -<P> - -<A NAME="IDX120"></A> -<DT><CODE>OPTARG</CODE> -<DD><A NAME="IDX121"></A> -The value of the last option argument processed by the <CODE>getopts</CODE> builtin. -<P> - -<A NAME="IDX122"></A> -<DT><CODE>OPTIND</CODE> -<DD><A NAME="IDX123"></A> -The index of the last option argument processed by the <CODE>getopts</CODE> builtin. -<P> - -<A NAME="IDX124"></A> -<DT><CODE>PATH</CODE> -<DD><A NAME="IDX125"></A> -A colon-separated list of directories in which the shell looks for -commands. -A zero-length (null) directory name in the value of <CODE>PATH</CODE> indicates the -current directory. -A null directory name may appear as two adjacent colons, or as an initial -or trailing colon. -<P> - -<A NAME="IDX126"></A> -<DT><CODE>PS1</CODE> -<DD><A NAME="IDX127"></A> -The primary prompt string. The default value is <SAMP>`\s-\v\$ '</SAMP>. -See section <A HREF="b.html#SEC86">6.9 Controlling the Prompt</A>, for the complete list of escape -sequences that are expanded before <CODE>PS1</CODE> is displayed. -<P> - -<A NAME="IDX128"></A> -<DT><CODE>PS2</CODE> -<DD><A NAME="IDX129"></A> -The secondary prompt string. The default value is <SAMP>`> '</SAMP>. -<P> - -</DL> -<P> - -<A NAME="Bash Variables"></A> -<HR SIZE="6"> -<A NAME="SEC65"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC64"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC63"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 5.2 Bash Variables </H2> -<!--docid::SEC65::--> -<P> - -These variables are set or used by Bash, but other shells -do not normally treat them specially. -</P><P> - -A few variables used by Bash are described in different chapters: -variables for controlling the job control facilities -(see section <A HREF="b.html#SEC92">7.3 Job Control Variables</A>). -</P><P> - -<DL COMPACT> - -<A NAME="IDX130"></A> -<DT><CODE>BASH</CODE> -<DD><A NAME="IDX131"></A> -The full pathname used to execute the current instance of Bash. -<P> - -<A NAME="IDX132"></A> -<DT><CODE>BASHPID</CODE> -<DD><A NAME="IDX133"></A> -Expands to the process id of the current Bash process. -This differs from <CODE>$$</CODE> under certain circumstances, such as subshells -that do not require Bash to be re-initialized. -<P> - -<A NAME="IDX134"></A> -<DT><CODE>BASH_ARGC</CODE> -<DD><A NAME="IDX135"></A> -An array variable whose values are the number of parameters in each -frame of the current bash execution call stack. The number of -parameters to the current subroutine (shell function or script executed -with <CODE>.</CODE> or <CODE>source</CODE>) is at the top of the stack. When a -subroutine is executed, the number of parameters passed is pushed onto -<CODE>BASH_ARGC</CODE>. -The shell sets <CODE>BASH_ARGC</CODE> only when in extended debugging mode -(see <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A> -for a description of the <CODE>extdebug</CODE> option to the <CODE>shopt</CODE> -builtin). -<P> - -<A NAME="IDX136"></A> -<DT><CODE>BASH_ARGV</CODE> -<DD><A NAME="IDX137"></A> -An array variable containing all of the parameters in the current bash -execution call stack. The final parameter of the last subroutine call -is at the top of the stack; the first parameter of the initial call is -at the bottom. When a subroutine is executed, the parameters supplied -are pushed onto <CODE>BASH_ARGV</CODE>. -The shell sets <CODE>BASH_ARGV</CODE> only when in extended debugging mode -(see <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A> -for a description of the <CODE>extdebug</CODE> option to the <CODE>shopt</CODE> -builtin). -<P> - -<A NAME="IDX138"></A> -<DT><CODE>BASH_COMMAND</CODE> -<DD><A NAME="IDX139"></A> -The command currently being executed or about to be executed, unless the -shell is executing a command as the result of a trap, -in which case it is the command executing at the time of the trap. -<P> - -<A NAME="IDX140"></A> -<DT><CODE>BASH_ENV</CODE> -<DD><A NAME="IDX141"></A> -If this variable is set when Bash is invoked to execute a shell -script, its value is expanded and used as the name of a startup file -to read before executing the script. See section <A HREF="b.html#SEC68">6.2 Bash Startup Files</A>. -<P> - -<A NAME="IDX142"></A> -<DT><CODE>BASH_EXECUTION_STRING</CODE> -<DD><A NAME="IDX143"></A> -The command argument to the <SAMP>`-c'</SAMP> invocation option. -<P> - -<A NAME="IDX144"></A> -<DT><CODE>BASH_LINENO</CODE> -<DD><A NAME="IDX145"></A> -An array variable whose members are the line numbers in source files -corresponding to each member of <VAR>FUNCNAME</VAR>. -<CODE>${BASH_LINENO[$i]}</CODE> is the line number in the source file where -<CODE>${FUNCNAME[$i]}</CODE> was called. -The corresponding source file name is <CODE>${BASH_SOURCE[$i]}</CODE>. -Use <CODE>LINENO</CODE> to obtain the current line number. -<P> - -<A NAME="IDX146"></A> -<DT><CODE>BASH_REMATCH</CODE> -<DD><A NAME="IDX147"></A> -An array variable whose members are assigned by the <SAMP>`=~'</SAMP> binary -operator to the <CODE>[[</CODE> conditional command -(see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>). -The element with index 0 is the portion of the string -matching the entire regular expression. -The element with index <VAR>n</VAR> is the portion of the -string matching the <VAR>n</VAR>th parenthesized subexpression. -This variable is read-only. -<P> - -<A NAME="IDX148"></A> -<DT><CODE>BASH_SOURCE</CODE> -<DD><A NAME="IDX149"></A> -An array variable whose members are the source filenames corresponding -to the elements in the <CODE>FUNCNAME</CODE> array variable. -<P> - -<A NAME="IDX150"></A> -<DT><CODE>BASH_SUBSHELL</CODE> -<DD><A NAME="IDX151"></A> -Incremented by one each time a subshell or subshell environment is spawned. -The initial value is 0. -<P> - -<A NAME="IDX152"></A> -<DT><CODE>BASH_VERSINFO</CODE> -<DD><A NAME="IDX153"></A> -A readonly array variable (see section <A HREF="b.html#SEC83">6.7 Arrays</A>) -whose members hold version information for this instance of Bash. -The values assigned to the array members are as follows: -<P> - -<DL COMPACT> - -<DT><CODE>BASH_VERSINFO[0]</CODE> -<DD>The major version number (the <VAR>release</VAR>). -<P> - -<DT><CODE>BASH_VERSINFO[1]</CODE> -<DD>The minor version number (the <VAR>version</VAR>). -<P> - -<DT><CODE>BASH_VERSINFO[2]</CODE> -<DD>The patch level. -<P> - -<DT><CODE>BASH_VERSINFO[3]</CODE> -<DD>The build version. -<P> - -<DT><CODE>BASH_VERSINFO[4]</CODE> -<DD>The release status (e.g., <VAR>beta1</VAR>). -<P> - -<DT><CODE>BASH_VERSINFO[5]</CODE> -<DD>The value of <CODE>MACHTYPE</CODE>. -<P> - -</DL> -<P> - -<A NAME="IDX154"></A> -<DT><CODE>BASH_VERSION</CODE> -<DD><A NAME="IDX155"></A> -The version number of the current instance of Bash. -<P> - -<A NAME="IDX156"></A> -<DT><CODE>COLUMNS</CODE> -<DD><A NAME="IDX157"></A> -Used by the <CODE>select</CODE> builtin command to determine the terminal width -when printing selection lists. Automatically set upon receipt of a -<CODE>SIGWINCH</CODE>. -<P> - -<A NAME="IDX158"></A> -<DT><CODE>COMP_CWORD</CODE> -<DD><A NAME="IDX159"></A> -An index into <CODE>${COMP_WORDS}</CODE> of the word containing the current -cursor position. -This variable is available only in shell functions invoked by the -programmable completion facilities (see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -<P> - -<A NAME="IDX160"></A> -<DT><CODE>COMP_LINE</CODE> -<DD><A NAME="IDX161"></A> -The current command line. -This variable is available only in shell functions and external -commands invoked by the -programmable completion facilities (see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -<P> - -<A NAME="IDX162"></A> -<DT><CODE>COMP_POINT</CODE> -<DD><A NAME="IDX163"></A> -The index of the current cursor position relative to the beginning of -the current command. -If the current cursor position is at the end of the current command, -the value of this variable is equal to <CODE>${#COMP_LINE}</CODE>. -This variable is available only in shell functions and external -commands invoked by the -programmable completion facilities (see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -<P> - -<A NAME="IDX164"></A> -<DT><CODE>COMP_TYPE</CODE> -<DD><A NAME="IDX165"></A> -Set to an integer value corresponding to the type of completion attempted -that caused a completion function to be called: -<VAR>TAB</VAR>, for normal completion, -<SAMP>`?'</SAMP>, for listing completions after successive tabs, -<SAMP>`!'</SAMP>, for listing alternatives on partial word completion, -<SAMP>`@'</SAMP>, to list completions if the word is not unmodified, -or -<SAMP>`%'</SAMP>, for menu completion. -This variable is available only in shell functions and external -commands invoked by the -programmable completion facilities (see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -<P> - -<A NAME="IDX166"></A> -<DT><CODE>COMP_KEY</CODE> -<DD><A NAME="IDX167"></A> -The key (or final key of a key sequence) used to invoke the current -completion function. -<P> - -<A NAME="IDX168"></A> -<DT><CODE>COMP_WORDBREAKS</CODE> -<DD><A NAME="IDX169"></A> -The set of characters that the Readline library treats as word -separators when performing word completion. -If <CODE>COMP_WORDBREAKS</CODE> is unset, it loses its special properties, -even if it is subsequently reset. -<P> - -<A NAME="IDX170"></A> -<DT><CODE>COMP_WORDS</CODE> -<DD><A NAME="IDX171"></A> -An array variable consisting of the individual -words in the current command line. -The words are split on shell metacharacters as the shell parser would -separate them. -This variable is available only in shell functions invoked by the -programmable completion facilities (see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -<P> - -<A NAME="IDX172"></A> -<DT><CODE>COMPREPLY</CODE> -<DD><A NAME="IDX173"></A> -An array variable from which Bash reads the possible completions -generated by a shell function invoked by the programmable completion -facility (see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -<P> - -<A NAME="IDX174"></A> -<DT><CODE>DIRSTACK</CODE> -<DD><A NAME="IDX175"></A> -An array variable containing the current contents of the directory stack. -Directories appear in the stack in the order they are displayed by the -<CODE>dirs</CODE> builtin. -Assigning to members of this array variable may be used to modify -directories already in the stack, but the <CODE>pushd</CODE> and <CODE>popd</CODE> -builtins must be used to add and remove directories. -Assignment to this variable will not change the current directory. -If <CODE>DIRSTACK</CODE> is unset, it loses its special properties, even if -it is subsequently reset. -<P> - -<A NAME="IDX176"></A> -<DT><CODE>EMACS</CODE> -<DD><A NAME="IDX177"></A> -If Bash finds this variable in the environment when the shell -starts with value <SAMP>`t'</SAMP>, it assumes that the shell is running in an -emacs shell buffer and disables line editing. -<P> - -<A NAME="IDX178"></A> -<DT><CODE>EUID</CODE> -<DD><A NAME="IDX179"></A> -The numeric effective user id of the current user. This variable -is readonly. -<P> - -<A NAME="IDX180"></A> -<DT><CODE>FCEDIT</CODE> -<DD><A NAME="IDX181"></A> -The editor used as a default by the <SAMP>`-e'</SAMP> option to the <CODE>fc</CODE> -builtin command. -<P> - -<A NAME="IDX182"></A> -<DT><CODE>FIGNORE</CODE> -<DD><A NAME="IDX183"></A> -A colon-separated list of suffixes to ignore when performing -filename completion. -A file name whose suffix matches one of the entries in -<CODE>FIGNORE</CODE> -is excluded from the list of matched file names. A sample -value is <SAMP>`.o:~'</SAMP> -<P> - -<A NAME="IDX184"></A> -<DT><CODE>FUNCNAME</CODE> -<DD><A NAME="IDX185"></A> -An array variable containing the names of all shell functions -currently in the execution call stack. -The element with index 0 is the name of any currently-executing -shell function. -The bottom-most element is <CODE>"main"</CODE>. -This variable exists only when a shell function is executing. -Assignments to <CODE>FUNCNAME</CODE> have no effect and return an error status. -If <CODE>FUNCNAME</CODE> is unset, it loses its special properties, even if -it is subsequently reset. -<P> - -<A NAME="IDX186"></A> -<DT><CODE>GLOBIGNORE</CODE> -<DD><A NAME="IDX187"></A> -A colon-separated list of patterns defining the set of filenames to -be ignored by filename expansion. -If a filename matched by a filename expansion pattern also matches one -of the patterns in <CODE>GLOBIGNORE</CODE>, it is removed from the list -of matches. -<P> - -<A NAME="IDX188"></A> -<DT><CODE>GROUPS</CODE> -<DD><A NAME="IDX189"></A> -An array variable containing the list of groups of which the current -user is a member. -Assignments to <CODE>GROUPS</CODE> have no effect and return an error status. -If <CODE>GROUPS</CODE> is unset, it loses its special properties, even if it is -subsequently reset. -<P> - -<A NAME="IDX190"></A> -<DT><CODE>histchars</CODE> -<DD><A NAME="IDX191"></A> -Up to three characters which control history expansion, quick -substitution, and tokenization (see section <A HREF="b.html#SEC120">9.3 History Expansion</A>). -The first character is the -<VAR>history expansion</VAR> character, that is, the character which signifies the -start of a history expansion, normally <SAMP>`!'</SAMP>. The second character is the -character which signifies `quick substitution' when seen as the first -character on a line, normally <SAMP>`^'</SAMP>. The optional third character is the -character which indicates that the remainder of the line is a comment when -found as the first character of a word, usually <SAMP>`#'</SAMP>. The history -comment character causes history substitution to be skipped for the -remaining words on the line. It does not necessarily cause the shell -parser to treat the rest of the line as a comment. -<P> - -<A NAME="IDX192"></A> -<DT><CODE>HISTCMD</CODE> -<DD><A NAME="IDX193"></A> -The history number, or index in the history list, of the current -command. If <CODE>HISTCMD</CODE> is unset, it loses its special properties, -even if it is subsequently reset. -<P> - -<A NAME="IDX194"></A> -<DT><CODE>HISTCONTROL</CODE> -<DD><A NAME="IDX195"></A> -A colon-separated list of values controlling how commands are saved on -the history list. -If the list of values includes <SAMP>`ignorespace'</SAMP>, lines which begin -with a space character are not saved in the history list. -A value of <SAMP>`ignoredups'</SAMP> causes lines which match the previous -history entry to not be saved. -A value of <SAMP>`ignoreboth'</SAMP> is shorthand for -<SAMP>`ignorespace'</SAMP> and <SAMP>`ignoredups'</SAMP>. -A value of <SAMP>`erasedups'</SAMP> causes all previous lines matching the -current line to be removed from the history list before that line -is saved. -Any value not in the above list is ignored. -If <CODE>HISTCONTROL</CODE> is unset, or does not include a valid value, -all lines read by the shell parser are saved on the history list, -subject to the value of <CODE>HISTIGNORE</CODE>. -The second and subsequent lines of a multi-line compound command are -not tested, and are added to the history regardless of the value of -<CODE>HISTCONTROL</CODE>. -<P> - -<A NAME="IDX196"></A> -<DT><CODE>HISTFILE</CODE> -<DD><A NAME="IDX197"></A> -The name of the file to which the command history is saved. The -default value is <TT>`~/.bash_history'</TT>. -<P> - -<A NAME="IDX198"></A> -<DT><CODE>HISTFILESIZE</CODE> -<DD><A NAME="IDX199"></A> -The maximum number of lines contained in the history file. When this -variable is assigned a value, the history file is truncated, if -necessary, by removing the oldest entries, -to contain no more than that number of lines. -The history file is also truncated to this size after -writing it when an interactive shell exits. -The default value is 500. -<P> - -<A NAME="IDX200"></A> -<DT><CODE>HISTIGNORE</CODE> -<DD><A NAME="IDX201"></A> -A colon-separated list of patterns used to decide which command -lines should be saved on the history list. Each pattern is -anchored at the beginning of the line and must match the complete -line (no implicit <SAMP>`*'</SAMP> is appended). Each pattern is tested -against the line after the checks specified by <CODE>HISTCONTROL</CODE> -are applied. In addition to the normal shell pattern matching -characters, <SAMP>`&'</SAMP> matches the previous history line. <SAMP>`&'</SAMP> -may be escaped using a backslash; the backslash is removed -before attempting a match. -The second and subsequent lines of a multi-line compound command are -not tested, and are added to the history regardless of the value of -<CODE>HISTIGNORE</CODE>. -<P> - -<CODE>HISTIGNORE</CODE> subsumes the function of <CODE>HISTCONTROL</CODE>. A -pattern of <SAMP>`&'</SAMP> is identical to <CODE>ignoredups</CODE>, and a -pattern of <SAMP>`[ ]*'</SAMP> is identical to <CODE>ignorespace</CODE>. -Combining these two patterns, separating them with a colon, -provides the functionality of <CODE>ignoreboth</CODE>. -</P><P> - -<A NAME="IDX202"></A> -<DT><CODE>HISTSIZE</CODE> -<DD><A NAME="IDX203"></A> -The maximum number of commands to remember on the history list. -The default value is 500. -<P> - -<A NAME="IDX204"></A> -<DT><CODE>HISTTIMEFORMAT</CODE> -<DD><A NAME="IDX205"></A> -If this variable is set and not null, its value is used as a format string -for <VAR>strftime</VAR> to print the time stamp associated with each history -entry displayed by the <CODE>history</CODE> builtin. -If this variable is set, time stamps are written to the history file so -they may be preserved across shell sessions. -<P> - -<A NAME="IDX206"></A> -<DT><CODE>HOSTFILE</CODE> -<DD><A NAME="IDX207"></A> -Contains the name of a file in the same format as <TT>`/etc/hosts'</TT> that -should be read when the shell needs to complete a hostname. -The list of possible hostname completions may be changed while the shell -is running; -the next time hostname completion is attempted after the -value is changed, Bash adds the contents of the new file to the -existing list. -If <CODE>HOSTFILE</CODE> is set, but has no value, Bash attempts to read -<TT>`/etc/hosts'</TT> to obtain the list of possible hostname completions. -When <CODE>HOSTFILE</CODE> is unset, the hostname list is cleared. -<P> - -<A NAME="IDX208"></A> -<DT><CODE>HOSTNAME</CODE> -<DD><A NAME="IDX209"></A> -The name of the current host. -<P> - -<A NAME="IDX210"></A> -<DT><CODE>HOSTTYPE</CODE> -<DD><A NAME="IDX211"></A> -A string describing the machine Bash is running on. -<P> - -<A NAME="IDX212"></A> -<DT><CODE>IGNOREEOF</CODE> -<DD><A NAME="IDX213"></A> -Controls the action of the shell on receipt of an <CODE>EOF</CODE> character -as the sole input. If set, the value denotes the number -of consecutive <CODE>EOF</CODE> characters that can be read as the -first character on an input line -before the shell will exit. If the variable exists but does not -have a numeric value (or has no value) then the default is 10. -If the variable does not exist, then <CODE>EOF</CODE> signifies the end of -input to the shell. This is only in effect for interactive shells. -<P> - -<A NAME="IDX214"></A> -<DT><CODE>INPUTRC</CODE> -<DD><A NAME="IDX215"></A> -The name of the Readline initialization file, overriding the default -of <TT>`~/.inputrc'</TT>. -<P> - -<A NAME="IDX216"></A> -<DT><CODE>LANG</CODE> -<DD><A NAME="IDX217"></A> -Used to determine the locale category for any category not specifically -selected with a variable starting with <CODE>LC_</CODE>. -<P> - -<A NAME="IDX218"></A> -<DT><CODE>LC_ALL</CODE> -<DD><A NAME="IDX219"></A> -This variable overrides the value of <CODE>LANG</CODE> and any other -<CODE>LC_</CODE> variable specifying a locale category. -<P> - -<A NAME="IDX220"></A> -<DT><CODE>LC_COLLATE</CODE> -<DD><A NAME="IDX221"></A> -This variable determines the collation order used when sorting the -results of filename expansion, and -determines the behavior of range expressions, equivalence classes, -and collating sequences within filename expansion and pattern matching -(see section <A HREF="b.html#SEC35">3.5.8 Filename Expansion</A>). -<P> - -<A NAME="IDX222"></A> -<DT><CODE>LC_CTYPE</CODE> -<DD><A NAME="IDX223"></A> -This variable determines the interpretation of characters and the -behavior of character classes within filename expansion and pattern -matching (see section <A HREF="b.html#SEC35">3.5.8 Filename Expansion</A>). -<P> - -<A NAME="IDX224"></A> -<DT><CODE>LC_MESSAGES</CODE> -<DD><A NAME="IDX225"></A> -This variable determines the locale used to translate double-quoted -strings preceded by a <SAMP>`$'</SAMP> (see section <A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A>). -<P> - -<A NAME="IDX226"></A> -<DT><CODE>LC_NUMERIC</CODE> -<DD><A NAME="IDX227"></A> -This variable determines the locale category used for number formatting. -<P> - -<A NAME="IDX228"></A> -<DT><CODE>LINENO</CODE> -<DD><A NAME="IDX229"></A> -The line number in the script or shell function currently executing. -<P> - -<A NAME="IDX230"></A> -<DT><CODE>LINES</CODE> -<DD><A NAME="IDX231"></A> -Used by the <CODE>select</CODE> builtin command to determine the column length -for printing selection lists. Automatically set upon receipt of a -<CODE>SIGWINCH</CODE>. -<P> - -<A NAME="IDX232"></A> -<DT><CODE>MACHTYPE</CODE> -<DD><A NAME="IDX233"></A> -A string that fully describes the system type on which Bash -is executing, in the standard GNU <VAR>cpu-company-system</VAR> format. -<P> - -<A NAME="IDX234"></A> -<DT><CODE>MAILCHECK</CODE> -<DD><A NAME="IDX235"></A> -How often (in seconds) that the shell should check for mail in the -files specified in the <CODE>MAILPATH</CODE> or <CODE>MAIL</CODE> variables. -The default is 60 seconds. When it is time to check -for mail, the shell does so before displaying the primary prompt. -If this variable is unset, or set to a value that is not a number -greater than or equal to zero, the shell disables mail checking. -<P> - -<A NAME="IDX236"></A> -<DT><CODE>OLDPWD</CODE> -<DD><A NAME="IDX237"></A> -The previous working directory as set by the <CODE>cd</CODE> builtin. -<P> - -<A NAME="IDX238"></A> -<DT><CODE>OPTERR</CODE> -<DD><A NAME="IDX239"></A> -If set to the value 1, Bash displays error messages -generated by the <CODE>getopts</CODE> builtin command. -<P> - -<A NAME="IDX240"></A> -<DT><CODE>OSTYPE</CODE> -<DD><A NAME="IDX241"></A> -A string describing the operating system Bash is running on. -<P> - -<A NAME="IDX242"></A> -<DT><CODE>PIPESTATUS</CODE> -<DD><A NAME="IDX243"></A> -An array variable (see section <A HREF="b.html#SEC83">6.7 Arrays</A>) -containing a list of exit status values from the processes -in the most-recently-executed foreground pipeline (which may -contain only a single command). -<P> - -<A NAME="IDX244"></A> -<DT><CODE>POSIXLY_CORRECT</CODE> -<DD><A NAME="IDX245"></A> -If this variable is in the environment when <CODE>bash</CODE> starts, the shell -enters POSIX mode (see section <A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A>) before reading the -startup files, as if the <SAMP>`--posix'</SAMP> invocation option had been supplied. -If it is set while the shell is running, <CODE>bash</CODE> enables POSIX mode, -as if the command -<TABLE><tr><td> </td><td class=example><pre><CODE>set -o posix</CODE> -</pre></td></tr></table>had been executed. -<P> - -<A NAME="IDX246"></A> -<DT><CODE>PPID</CODE> -<DD><A NAME="IDX247"></A> -The process ID of the shell's parent process. This variable -is readonly. -<P> - -<A NAME="IDX248"></A> -<DT><CODE>PROMPT_COMMAND</CODE> -<DD><A NAME="IDX249"></A> -If set, the value is interpreted as a command to execute -before the printing of each primary prompt (<CODE>$PS1</CODE>). -<P> - -<A NAME="IDX250"></A> -<DT><CODE>PS3</CODE> -<DD><A NAME="IDX251"></A> -The value of this variable is used as the prompt for the -<CODE>select</CODE> command. If this variable is not set, the -<CODE>select</CODE> command prompts with <SAMP>`#? '</SAMP> -<P> - -<A NAME="IDX252"></A> -<DT><CODE>PS4</CODE> -<DD><A NAME="IDX253"></A> -The value is the prompt printed before the command line is echoed -when the <SAMP>`-x'</SAMP> option is set (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -The first character of <CODE>PS4</CODE> is replicated multiple times, as -necessary, to indicate multiple levels of indirection. -The default is <SAMP>`+ '</SAMP>. -<P> - -<A NAME="IDX254"></A> -<DT><CODE>PWD</CODE> -<DD><A NAME="IDX255"></A> -The current working directory as set by the <CODE>cd</CODE> builtin. -<P> - -<A NAME="IDX256"></A> -<DT><CODE>RANDOM</CODE> -<DD><A NAME="IDX257"></A> -Each time this parameter is referenced, a random integer -between 0 and 32767 is generated. Assigning a value to this -variable seeds the random number generator. -<P> - -<A NAME="IDX258"></A> -<DT><CODE>REPLY</CODE> -<DD><A NAME="IDX259"></A> -The default variable for the <CODE>read</CODE> builtin. -<P> - -<A NAME="IDX260"></A> -<DT><CODE>SECONDS</CODE> -<DD><A NAME="IDX261"></A> -This variable expands to the number of seconds since the -shell was started. Assignment to this variable resets -the count to the value assigned, and the expanded value -becomes the value assigned plus the number of seconds -since the assignment. -<P> - -<A NAME="IDX262"></A> -<DT><CODE>SHELL</CODE> -<DD><A NAME="IDX263"></A> -The full pathname to the shell is kept in this environment variable. -If it is not set when the shell starts, -Bash assigns to it the full pathname of the current user's login shell. -<P> - -<A NAME="IDX264"></A> -<DT><CODE>SHELLOPTS</CODE> -<DD><A NAME="IDX265"></A> -A colon-separated list of enabled shell options. Each word in -the list is a valid argument for the <SAMP>`-o'</SAMP> option to the -<CODE>set</CODE> builtin command (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -The options appearing in <CODE>SHELLOPTS</CODE> are those reported -as <SAMP>`on'</SAMP> by <SAMP>`set -o'</SAMP>. -If this variable is in the environment when Bash -starts up, each shell option in the list will be enabled before -reading any startup files. This variable is readonly. -<P> - -<A NAME="IDX266"></A> -<DT><CODE>SHLVL</CODE> -<DD><A NAME="IDX267"></A> -Incremented by one each time a new instance of Bash is started. This is -intended to be a count of how deeply your Bash shells are nested. -<P> - -<A NAME="IDX268"></A> -<DT><CODE>TIMEFORMAT</CODE> -<DD><A NAME="IDX269"></A> -The value of this parameter is used as a format string specifying -how the timing information for pipelines prefixed with the <CODE>time</CODE> -reserved word should be displayed. -The <SAMP>`%'</SAMP> character introduces an -escape sequence that is expanded to a time value or other -information. -The escape sequences and their meanings are as -follows; the braces denote optional portions. -<P> - -<DL COMPACT> - -<DT><CODE>%%</CODE> -<DD>A literal <SAMP>`%'</SAMP>. -<P> - -<DT><CODE>%[<VAR>p</VAR>][l]R</CODE> -<DD>The elapsed time in seconds. -<P> - -<DT><CODE>%[<VAR>p</VAR>][l]U</CODE> -<DD>The number of CPU seconds spent in user mode. -<P> - -<DT><CODE>%[<VAR>p</VAR>][l]S</CODE> -<DD>The number of CPU seconds spent in system mode. -<P> - -<DT><CODE>%P</CODE> -<DD>The CPU percentage, computed as (%U + %S) / %R. -</DL> -<P> - -The optional <VAR>p</VAR> is a digit specifying the precision, the number of -fractional digits after a decimal point. -A value of 0 causes no decimal point or fraction to be output. -At most three places after the decimal point may be specified; values -of <VAR>p</VAR> greater than 3 are changed to 3. -If <VAR>p</VAR> is not specified, the value 3 is used. -</P><P> - -The optional <CODE>l</CODE> specifies a longer format, including minutes, of -the form <VAR>MM</VAR>m<VAR>SS</VAR>.<VAR>FF</VAR>s. -The value of <VAR>p</VAR> determines whether or not the fraction is included. -</P><P> - -If this variable is not set, Bash acts as if it had the value -<TABLE><tr><td> </td><td class=example><pre><CODE>$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS'</CODE> -</pre></td></tr></table>If the value is null, no timing information is displayed. -A trailing newline is added when the format string is displayed. -</P><P> - -<A NAME="IDX270"></A> -<DT><CODE>TMOUT</CODE> -<DD><A NAME="IDX271"></A> -If set to a value greater than zero, <CODE>TMOUT</CODE> is treated as the -default timeout for the <CODE>read</CODE> builtin (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -The <CODE>select</CODE> command (see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>) terminates -if input does not arrive after <CODE>TMOUT</CODE> seconds when input is coming -from a terminal. -<P> - -In an interactive shell, the value is interpreted as -the number of seconds to wait for input after issuing the primary -prompt when the shell is interactive. -Bash terminates after that number of seconds if input does -not arrive. -</P><P> - -<A NAME="IDX272"></A> -<DT><CODE>TMPDIR</CODE> -<DD><A NAME="IDX273"></A> -If set, Bash uses its value as the name of a directory in which -Bash creates temporary files for the shell's use. -<P> - -<A NAME="IDX274"></A> -<DT><CODE>UID</CODE> -<DD><A NAME="IDX275"></A> -The numeric real user id of the current user. This variable is readonly. -<P> - -</DL> -<P> - -<A NAME="Bash Features"></A> -<HR SIZE="6"> -<A NAME="SEC66"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC65"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC67"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 6. Bash Features </H1> -<!--docid::SEC66::--> -<P> - -This section describes features unique to Bash. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC67">6.1 Invoking Bash</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Command line options that you can give - to Bash.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC68">6.2 Bash Startup Files</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">When and how Bash executes scripts.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC76">6.3 Interactive Shells</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What an interactive shell is.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC80">6.4 Bash Conditional Expressions</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Primitives used in composing expressions for - the <CODE>test</CODE> builtin.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC81">6.5 Shell Arithmetic</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Arithmetic on shell variables.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC82">6.6 Aliases</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Substituting one command for another.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC83">6.7 Arrays</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Array Variables.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC84">6.8 The Directory Stack</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">History of visited directories.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC86">6.9 Controlling the Prompt</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Controlling the PS1 string.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC87">6.10 The Restricted Shell</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A more controlled mode of shell execution.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Making Bash behave more closely to what - the POSIX standard specifies.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Invoking Bash"></A> -<HR SIZE="6"> -<A NAME="SEC67"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC68"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.1 Invoking Bash </H2> -<!--docid::SEC67::--> -<P> - -<TABLE><tr><td> </td><td class=example><pre>bash [long-opt] [-ir] [-abefhkmnptuvxdBCDHP] [-o <VAR>option</VAR>] [-O <VAR>shopt_option</VAR>] [<VAR>argument</VAR> <small>...</small>] -bash [long-opt] [-abefhkmnptuvxdBCDHP] [-o <VAR>option</VAR>] [-O <VAR>shopt_option</VAR>] -c <VAR>string</VAR> [<VAR>argument</VAR> <small>...</small>] -bash [long-opt] -s [-abefhkmnptuvxdBCDHP] [-o <VAR>option</VAR>] [-O <VAR>shopt_option</VAR>] [<VAR>argument</VAR> <small>...</small>] -</pre></td></tr></table></P><P> - -In addition to the single-character shell command-line options -(see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>), there are several multi-character -options that you can use. These options must appear on the command -line before the single-character options to be recognized. -</P><P> - -<DL COMPACT> -<DT><CODE>--debugger</CODE> -<DD>Arrange for the debugger profile to be executed before the shell -starts. Turns on extended debugging mode (see <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A> -for a description of the <CODE>extdebug</CODE> option to the <CODE>shopt</CODE> -builtin) and shell function tracing -(see <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A> for a description of the <CODE>-o functrace</CODE> -option). -<P> - -<DT><CODE>--dump-po-strings</CODE> -<DD>A list of all double-quoted strings preceded by <SAMP>`$'</SAMP> -is printed on the standard output -in the GNU <CODE>gettext</CODE> PO (portable object) file format. -Equivalent to <SAMP>`-D'</SAMP> except for the output format. -<P> - -<DT><CODE>--dump-strings</CODE> -<DD>Equivalent to <SAMP>`-D'</SAMP>. -<P> - -<DT><CODE>--help</CODE> -<DD>Display a usage message on standard output and exit successfully. -<P> - -<DT><CODE>--init-file <VAR>filename</VAR></CODE> -<DD><DT><CODE>--rcfile <VAR>filename</VAR></CODE> -<DD>Execute commands from <VAR>filename</VAR> (instead of <TT>`~/.bashrc'</TT>) -in an interactive shell. -<P> - -<DT><CODE>--login</CODE> -<DD>Equivalent to <SAMP>`-l'</SAMP>. -<P> - -<DT><CODE>--noediting</CODE> -<DD>Do not use the GNU Readline library (see section <A HREF="b.html#SEC93">8. Command Line Editing</A>) -to read command lines when the shell is interactive. -<P> - -<DT><CODE>--noprofile</CODE> -<DD>Don't load the system-wide startup file <TT>`/etc/profile'</TT> -or any of the personal initialization files -<TT>`~/.bash_profile'</TT>, <TT>`~/.bash_login'</TT>, or <TT>`~/.profile'</TT> -when Bash is invoked as a login shell. -<P> - -<DT><CODE>--norc</CODE> -<DD>Don't read the <TT>`~/.bashrc'</TT> initialization file in an -interactive shell. This is on by default if the shell is -invoked as <CODE>sh</CODE>. -<P> - -<DT><CODE>--posix</CODE> -<DD>Change the behavior of Bash where the default operation differs -from the POSIX standard to match the standard. This -is intended to make Bash behave as a strict superset of that -standard. See section <A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A>, for a description of the Bash -POSIX mode. -<P> - -<DT><CODE>--restricted</CODE> -<DD>Make the shell a restricted shell (see section <A HREF="b.html#SEC87">6.10 The Restricted Shell</A>). -<P> - -<DT><CODE>--verbose</CODE> -<DD>Equivalent to <SAMP>`-v'</SAMP>. Print shell input lines as they're read. -<P> - -<DT><CODE>--version</CODE> -<DD>Show version information for this instance of -Bash on the standard output and exit successfully. -<P> - -</DL> -<P> - -There are several single-character options that may be supplied at -invocation which are not available with the <CODE>set</CODE> builtin. -</P><P> - -<DL COMPACT> -<DT><CODE>-c <VAR>string</VAR></CODE> -<DD>Read and execute commands from <VAR>string</VAR> after processing the -options, then exit. Any remaining arguments are assigned to the -positional parameters, starting with <CODE>$0</CODE>. -<P> - -<DT><CODE>-i</CODE> -<DD>Force the shell to run interactively. Interactive shells are -described in <A HREF="b.html#SEC76">6.3 Interactive Shells</A>. -<P> - -<DT><CODE>-l</CODE> -<DD>Make this shell act as if it had been directly invoked by login. -When the shell is interactive, this is equivalent to starting a -login shell with <SAMP>`exec -l bash'</SAMP>. -When the shell is not interactive, the login shell startup files will -be executed. -<SAMP>`exec bash -l'</SAMP> or <SAMP>`exec bash --login'</SAMP> -will replace the current shell with a Bash login shell. -See section <A HREF="b.html#SEC68">6.2 Bash Startup Files</A>, for a description of the special behavior -of a login shell. -<P> - -<DT><CODE>-r</CODE> -<DD>Make the shell a restricted shell (see section <A HREF="b.html#SEC87">6.10 The Restricted Shell</A>). -<P> - -<DT><CODE>-s</CODE> -<DD>If this option is present, or if no arguments remain after option -processing, then commands are read from the standard input. -This option allows the positional parameters to be set -when invoking an interactive shell. -<P> - -<DT><CODE>-D</CODE> -<DD>A list of all double-quoted strings preceded by <SAMP>`$'</SAMP> -is printed on the standard output. -These are the strings that -are subject to language translation when the current locale -is not <CODE>C</CODE> or <CODE>POSIX</CODE> (see section <A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A>). -This implies the <SAMP>`-n'</SAMP> option; no commands will be executed. -<P> - -<DT><CODE>[-+]O [<VAR>shopt_option</VAR>]</CODE> -<DD><VAR>shopt_option</VAR> is one of the shell options accepted by the -<CODE>shopt</CODE> builtin (see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>). -If <VAR>shopt_option</VAR> is present, <SAMP>`-O'</SAMP> sets the value of that option; -<SAMP>`+O'</SAMP> unsets it. -If <VAR>shopt_option</VAR> is not supplied, the names and values of the shell -options accepted by <CODE>shopt</CODE> are printed on the standard output. -If the invocation option is <SAMP>`+O'</SAMP>, the output is displayed in a format -that may be reused as input. -<P> - -<DT><CODE>--</CODE> -<DD>A <CODE>--</CODE> signals the end of options and disables further option -processing. -Any arguments after the <CODE>--</CODE> are treated as filenames and arguments. -<P> - -</DL> -<P> - -<A NAME="IDX276"></A> -A <EM>login</EM> shell is one whose first character of argument zero is -<SAMP>`-'</SAMP>, or one invoked with the <SAMP>`--login'</SAMP> option. -</P><P> - -<A NAME="IDX277"></A> -An <EM>interactive</EM> shell is one started without non-option arguments, -unless <SAMP>`-s'</SAMP> is specified, -without specifying the <SAMP>`-c'</SAMP> option, and whose input and output are both -connected to terminals (as determined by <CODE>isatty(3)</CODE>), or one -started with the <SAMP>`-i'</SAMP> option. See section <A HREF="b.html#SEC76">6.3 Interactive Shells</A>, for more -information. -</P><P> - -If arguments remain after option processing, and neither the -<SAMP>`-c'</SAMP> nor the <SAMP>`-s'</SAMP> -option has been supplied, the first argument is assumed to -be the name of a file containing shell commands (see section <A HREF="b.html#SEC55">3.8 Shell Scripts</A>). -When Bash is invoked in this fashion, <CODE>$0</CODE> -is set to the name of the file, and the positional parameters -are set to the remaining arguments. -Bash reads and executes commands from this file, then exits. -Bash's exit status is the exit status of the last command executed -in the script. If no commands are executed, the exit status is 0. -</P><P> - -<A NAME="Bash Startup Files"></A> -<HR SIZE="6"> -<A NAME="SEC68"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC67"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC76"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC76"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.2 Bash Startup Files </H2> -<!--docid::SEC68::--> -<P> - -This section describes how Bash executes its startup files. -If any of the files exist but cannot be read, Bash reports an error. -Tildes are expanded in file names as described above under -Tilde Expansion (see section <A HREF="b.html#SEC29">3.5.2 Tilde Expansion</A>). -</P><P> - -Interactive shells are described in <A HREF="b.html#SEC76">6.3 Interactive Shells</A>. -</P><P> - -<A NAME="SEC69"></A> -<H4> Invoked as an interactive login shell, or with <SAMP>`--login'</SAMP> </H4> -<!--docid::SEC69::--> -<P> - -When Bash is invoked as an interactive login shell, or as a -non-interactive shell with the <SAMP>`--login'</SAMP> option, it first reads and -executes commands from the file <TT>`/etc/profile'</TT>, if that file exists. -After reading that file, it looks for <TT>`~/.bash_profile'</TT>, -<TT>`~/.bash_login'</TT>, and <TT>`~/.profile'</TT>, in that order, and reads -and executes commands from the first one that exists and is readable. -The <SAMP>`--noprofile'</SAMP> option may be used when the shell is started to -inhibit this behavior. -</P><P> - -When a login shell exits, Bash reads and executes commands from -the file <TT>`~/.bash_logout'</TT>, if it exists. -</P><P> - -<A NAME="SEC70"></A> -<H4> Invoked as an interactive non-login shell </H4> -<!--docid::SEC70::--> -<P> - -When an interactive shell that is not a login shell is started, Bash -reads and executes commands from <TT>`~/.bashrc'</TT>, if that file exists. -This may be inhibited by using the <SAMP>`--norc'</SAMP> option. -The <SAMP>`--rcfile <VAR>file</VAR>'</SAMP> option will force Bash to read and -execute commands from <VAR>file</VAR> instead of <TT>`~/.bashrc'</TT>. -</P><P> - -So, typically, your <TT>`~/.bash_profile'</TT> contains the line -<TABLE><tr><td> </td><td class=example><pre><CODE>if [ -f ~/.bashrc ]; then . ~/.bashrc; fi</CODE> -</pre></td></tr></table>after (or before) any login-specific initializations. -</P><P> - -<A NAME="SEC71"></A> -<H4> Invoked non-interactively </H4> -<!--docid::SEC71::--> -<P> - -When Bash is started non-interactively, to run a shell script, -for example, it looks for the variable <CODE>BASH_ENV</CODE> in the environment, -expands its value if it appears there, and uses the expanded value as -the name of a file to read and execute. Bash behaves as if the -following command were executed: -<TABLE><tr><td> </td><td class=example><pre><CODE>if [ -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi</CODE> -</pre></td></tr></table>but the value of the <CODE>PATH</CODE> variable is not used to search for the -file name. -</P><P> - -As noted above, if a non-interactive shell is invoked with the -<SAMP>`--login'</SAMP> option, Bash attempts to read and execute commands from the -login shell startup files. -</P><P> - -<A NAME="SEC72"></A> -<H4> Invoked with name <CODE>sh</CODE> </H4> -<!--docid::SEC72::--> -<P> - -If Bash is invoked with the name <CODE>sh</CODE>, it tries to mimic the -startup behavior of historical versions of <CODE>sh</CODE> as closely as -possible, while conforming to the POSIX standard as well. -</P><P> - -When invoked as an interactive login shell, or as a non-interactive -shell with the <SAMP>`--login'</SAMP> option, it first attempts to read -and execute commands from <TT>`/etc/profile'</TT> and <TT>`~/.profile'</TT>, in -that order. -The <SAMP>`--noprofile'</SAMP> option may be used to inhibit this behavior. -When invoked as an interactive shell with the name <CODE>sh</CODE>, Bash -looks for the variable <CODE>ENV</CODE>, expands its value if it is defined, -and uses the expanded value as the name of a file to read and execute. -Since a shell invoked as <CODE>sh</CODE> does not attempt to read and execute -commands from any other startup files, the <SAMP>`--rcfile'</SAMP> option has -no effect. -A non-interactive shell invoked with the name <CODE>sh</CODE> does not attempt -to read any other startup files. -</P><P> - -When invoked as <CODE>sh</CODE>, Bash enters POSIX mode after -the startup files are read. -</P><P> - -<A NAME="SEC73"></A> -<H4> Invoked in POSIX mode </H4> -<!--docid::SEC73::--> -<P> - -When Bash is started in POSIX mode, as with the -<SAMP>`--posix'</SAMP> command line option, it follows the POSIX standard -for startup files. -In this mode, interactive shells expand the <CODE>ENV</CODE> variable -and commands are read and executed from the file whose name is the -expanded value. -No other startup files are read. -</P><P> - -<A NAME="SEC74"></A> -<H4> Invoked by remote shell daemon </H4> -<!--docid::SEC74::--> -<P> - -Bash attempts to determine when it is being run by the remote shell -daemon, usually <CODE>rshd</CODE>. If Bash determines it is being run by -rshd, it reads and executes commands from <TT>`~/.bashrc'</TT>, if that -file exists and is readable. -It will not do this if invoked as <CODE>sh</CODE>. -The <SAMP>`--norc'</SAMP> option may be used to inhibit this behavior, and the -<SAMP>`--rcfile'</SAMP> option may be used to force another file to be read, but -<CODE>rshd</CODE> does not generally invoke the shell with those options or -allow them to be specified. -</P><P> - -<A NAME="SEC75"></A> -<H4> Invoked with unequal effective and real UID/GIDs </H4> -<!--docid::SEC75::--> -<P> - -If Bash is started with the effective user (group) id not equal to the -real user (group) id, and the <CODE>-p</CODE> option is not supplied, no startup -files are read, shell functions are not inherited from the environment, -the <CODE>SHELLOPTS</CODE> variable, if it appears in the environment, is ignored, -and the effective user id is set to the real user id. -If the <CODE>-p</CODE> option is supplied at invocation, the startup behavior is -the same, but the effective user id is not reset. -</P><P> - -<A NAME="Interactive Shells"></A> -<HR SIZE="6"> -<A NAME="SEC76"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC68"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC77"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.3 Interactive Shells </H2> -<!--docid::SEC76::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC77">6.3.1 What is an Interactive Shell?</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What determines whether a shell is Interactive.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC78">6.3.2 Is this Shell Interactive?</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to tell if a shell is interactive.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC79">6.3.3 Interactive Shell Behavior</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What changes in a interactive shell?</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="What is an Interactive Shell?"></A> -<HR SIZE="6"> -<A NAME="SEC77"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC76"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC78"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC76"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 6.3.1 What is an Interactive Shell? </H3> -<!--docid::SEC77::--> -<P> - -An interactive shell -is one started without non-option arguments, unless <SAMP>`-s'</SAMP> is -specified, without specifying the <SAMP>`-c'</SAMP> option, and -whose input and error output are both -connected to terminals (as determined by <CODE>isatty(3)</CODE>), -or one started with the <SAMP>`-i'</SAMP> option. -</P><P> - -An interactive shell generally reads from and writes to a user's -terminal. -</P><P> - -The <SAMP>`-s'</SAMP> invocation option may be used to set the positional parameters -when an interactive shell is started. -</P><P> - -<A NAME="Is this Shell Interactive?"></A> -<HR SIZE="6"> -<A NAME="SEC78"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC77"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC79"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC79"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC76"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 6.3.2 Is this Shell Interactive? </H3> -<!--docid::SEC78::--> -<P> - -To determine within a startup script whether or not Bash is -running interactively, -test the value of the <SAMP>`-'</SAMP> special parameter. -It contains <CODE>i</CODE> when the shell is interactive. For example: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>case "$-" in -*i*) echo This shell is interactive ;; -*) echo This shell is not interactive ;; -esac -</pre></td></tr></table></P><P> - -Alternatively, startup scripts may examine the variable -<CODE>PS1</CODE>; it is unset in non-interactive shells, and set in -interactive shells. Thus: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>if [ -z "$PS1" ]; then - echo This shell is not interactive -else - echo This shell is interactive -fi -</pre></td></tr></table></P><P> - -<A NAME="Interactive Shell Behavior"></A> -<HR SIZE="6"> -<A NAME="SEC79"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC78"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC76"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 6.3.3 Interactive Shell Behavior </H3> -<!--docid::SEC79::--> -<P> - -When the shell is running interactively, it changes its behavior in -several ways. -</P><P> - -<OL> -<LI> -Startup files are read and executed as described in <A HREF="b.html#SEC68">6.2 Bash Startup Files</A>. -<P> - -<LI> -Job Control (see section <A HREF="b.html#SEC89">7. Job Control</A>) is enabled by default. When job -control is in effect, Bash ignores the keyboard-generated job control -signals <CODE>SIGTTIN</CODE>, <CODE>SIGTTOU</CODE>, and <CODE>SIGTSTP</CODE>. -<P> - -<LI> -Bash expands and displays <CODE>PS1</CODE> before reading the first line -of a command, and expands and displays <CODE>PS2</CODE> before reading the -second and subsequent lines of a multi-line command. -<P> - -<LI> -Bash executes the value of the <CODE>PROMPT_COMMAND</CODE> variable as a command -before printing the primary prompt, <CODE>$PS1</CODE> -(see section <A HREF="b.html#SEC65">5.2 Bash Variables</A>). -<P> - -<LI> -Readline (see section <A HREF="b.html#SEC93">8. Command Line Editing</A>) is used to read commands from -the user's terminal. -<P> - -<LI> -Bash inspects the value of the <CODE>ignoreeof</CODE> option to <CODE>set -o</CODE> -instead of exiting immediately when it receives an <CODE>EOF</CODE> on its -standard input when reading a command (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -<P> - -<LI> -Command history (see section <A HREF="b.html#SEC118">9.1 Bash History Facilities</A>) -and history expansion (see section <A HREF="b.html#SEC120">9.3 History Expansion</A>) -are enabled by default. -Bash will save the command history to the file named by <CODE>$HISTFILE</CODE> -when an interactive shell exits. -<P> - -<LI> -Alias expansion (see section <A HREF="b.html#SEC82">6.6 Aliases</A>) is performed by default. -<P> - -<LI> -In the absence of any traps, Bash ignores <CODE>SIGTERM</CODE> -(see section <A HREF="b.html#SEC54">3.7.6 Signals</A>). -<P> - -<LI> -In the absence of any traps, <CODE>SIGINT</CODE> is caught and handled -((see section <A HREF="b.html#SEC54">3.7.6 Signals</A>). -<CODE>SIGINT</CODE> will interrupt some shell builtins. -<P> - -<LI> -An interactive login shell sends a <CODE>SIGHUP</CODE> to all jobs on exit -if the <CODE>huponexit</CODE> shell option has been enabled (see section <A HREF="b.html#SEC54">3.7.6 Signals</A>). -<P> - -<LI> -The <SAMP>`-n'</SAMP> invocation option is ignored, and <SAMP>`set -n'</SAMP> has -no effect (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -<P> - -<LI> -Bash will check for mail periodically, depending on the values of the -<CODE>MAIL</CODE>, <CODE>MAILPATH</CODE>, and <CODE>MAILCHECK</CODE> shell variables -(see section <A HREF="b.html#SEC65">5.2 Bash Variables</A>). -<P> - -<LI> -Expansion errors due to references to unbound shell variables after -<SAMP>`set -u'</SAMP> has been enabled will not cause the shell to exit -(see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -<P> - -<LI> -The shell will not exit on expansion errors caused by <VAR>var</VAR> being unset -or null in <CODE>${<VAR>var</VAR>:?<VAR>word</VAR>}</CODE> expansions -(see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -<P> - -<LI> -Redirection errors encountered by shell builtins will not cause the -shell to exit. -<P> - -<LI> -When running in POSIX mode, a special builtin returning an error -status will not cause the shell to exit (see section <A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A>). -<P> - -<LI> -A failed <CODE>exec</CODE> will not cause the shell to exit -(see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -<P> - -<LI> -Parser syntax errors will not cause the shell to exit. -<P> - -<LI> -Simple spelling correction for directory arguments to the <CODE>cd</CODE> -builtin is enabled by default (see the description of the <CODE>cdspell</CODE> -option to the <CODE>shopt</CODE> builtin in <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>). -<P> - -<LI> -The shell will check the value of the <CODE>TMOUT</CODE> variable and exit -if a command is not read within the specified number of seconds after -printing <CODE>$PS1</CODE> (see section <A HREF="b.html#SEC65">5.2 Bash Variables</A>). -<P> - -</OL> -<P> - -<A NAME="Bash Conditional Expressions"></A> -<HR SIZE="6"> -<A NAME="SEC80"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC79"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC81"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC81"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.4 Bash Conditional Expressions </H2> -<!--docid::SEC80::--> -<P> - -Conditional expressions are used by the <CODE>[[</CODE> compound command -and the <CODE>test</CODE> and <CODE>[</CODE> builtin commands. -</P><P> - -Expressions may be unary or binary. -Unary expressions are often used to examine the status of a file. -There are string operators and numeric comparison operators as well. -If the <VAR>file</VAR> argument to one of the primaries is of the form -<TT>`/dev/fd/<VAR>N</VAR>'</TT>, then file descriptor <VAR>N</VAR> is checked. -If the <VAR>file</VAR> argument to one of the primaries is one of -<TT>`/dev/stdin'</TT>, <TT>`/dev/stdout'</TT>, or <TT>`/dev/stderr'</TT>, file -descriptor 0, 1, or 2, respectively, is checked. -</P><P> - -Unless otherwise specified, primaries that operate on files follow symbolic -links and operate on the target of the link, rather than the link itself. -</P><P> - -<DL COMPACT> -<DT><CODE>-a <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists. -<P> - -<DT><CODE>-b <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a block special file. -<P> - -<DT><CODE>-c <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a character special file. -<P> - -<DT><CODE>-d <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a directory. -<P> - -<DT><CODE>-e <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists. -<P> - -<DT><CODE>-f <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a regular file. -<P> - -<DT><CODE>-g <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and its set-group-id bit is set. -<P> - -<DT><CODE>-h <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a symbolic link. -<P> - -<DT><CODE>-k <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and its "sticky" bit is set. -<P> - -<DT><CODE>-p <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a named pipe (FIFO). -<P> - -<DT><CODE>-r <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is readable. -<P> - -<DT><CODE>-s <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and has a size greater than zero. -<P> - -<DT><CODE>-t <VAR>fd</VAR></CODE> -<DD>True if file descriptor <VAR>fd</VAR> is open and refers to a terminal. -<P> - -<DT><CODE>-u <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and its set-user-id bit is set. -<P> - -<DT><CODE>-w <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is writable. -<P> - -<DT><CODE>-x <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is executable. -<P> - -<DT><CODE>-O <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is owned by the effective user id. -<P> - -<DT><CODE>-G <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is owned by the effective group id. -<P> - -<DT><CODE>-L <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a symbolic link. -<P> - -<DT><CODE>-S <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and is a socket. -<P> - -<DT><CODE>-N <VAR>file</VAR></CODE> -<DD>True if <VAR>file</VAR> exists and has been modified since it was last read. -<P> - -<DT><CODE><VAR>file1</VAR> -nt <VAR>file2</VAR></CODE> -<DD>True if <VAR>file1</VAR> is newer (according to modification date) -than <VAR>file2</VAR>, or if <VAR>file1</VAR> exists and <VAR>file2</VAR> does not. -<P> - -<DT><CODE><VAR>file1</VAR> -ot <VAR>file2</VAR></CODE> -<DD>True if <VAR>file1</VAR> is older than <VAR>file2</VAR>, -or if <VAR>file2</VAR> exists and <VAR>file1</VAR> does not. -<P> - -<DT><CODE><VAR>file1</VAR> -ef <VAR>file2</VAR></CODE> -<DD>True if <VAR>file1</VAR> and <VAR>file2</VAR> refer to the same device and -inode numbers. -<P> - -<DT><CODE>-o <VAR>optname</VAR></CODE> -<DD>True if shell option <VAR>optname</VAR> is enabled. -The list of options appears in the description of the <SAMP>`-o'</SAMP> -option to the <CODE>set</CODE> builtin (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -<P> - -<DT><CODE>-z <VAR>string</VAR></CODE> -<DD>True if the length of <VAR>string</VAR> is zero. -<P> - -<DT><CODE>-n <VAR>string</VAR></CODE> -<DD><DT><CODE><VAR>string</VAR></CODE> -<DD>True if the length of <VAR>string</VAR> is non-zero. -<P> - -<DT><CODE><VAR>string1</VAR> == <VAR>string2</VAR></CODE> -<DD>True if the strings are equal. -<SAMP>`='</SAMP> may be used in place of <SAMP>`=='</SAMP> for strict POSIX compliance. -<P> - -<DT><CODE><VAR>string1</VAR> != <VAR>string2</VAR></CODE> -<DD>True if the strings are not equal. -<P> - -<DT><CODE><VAR>string1</VAR> < <VAR>string2</VAR></CODE> -<DD>True if <VAR>string1</VAR> sorts before <VAR>string2</VAR> lexicographically -in the current locale. -<P> - -<DT><CODE><VAR>string1</VAR> > <VAR>string2</VAR></CODE> -<DD>True if <VAR>string1</VAR> sorts after <VAR>string2</VAR> lexicographically -in the current locale. -<P> - -<DT><CODE><VAR>arg1</VAR> OP <VAR>arg2</VAR></CODE> -<DD><CODE>OP</CODE> is one of -<SAMP>`-eq'</SAMP>, <SAMP>`-ne'</SAMP>, <SAMP>`-lt'</SAMP>, <SAMP>`-le'</SAMP>, <SAMP>`-gt'</SAMP>, or <SAMP>`-ge'</SAMP>. -These arithmetic binary operators return true if <VAR>arg1</VAR> -is equal to, not equal to, less than, less than or equal to, -greater than, or greater than or equal to <VAR>arg2</VAR>, -respectively. <VAR>Arg1</VAR> and <VAR>arg2</VAR> -may be positive or negative integers. -<P> - -</DL> -<P> - -<A NAME="Shell Arithmetic"></A> -<HR SIZE="6"> -<A NAME="SEC81"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC80"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC82"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC82"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.5 Shell Arithmetic </H2> -<!--docid::SEC81::--> -<P> - -The shell allows arithmetic expressions to be evaluated, as one of -the shell expansions or by the <CODE>let</CODE> and the <SAMP>`-i'</SAMP> option -to the <CODE>declare</CODE> builtins. -</P><P> - -Evaluation is done in fixed-width integers with no check for overflow, -though division by 0 is trapped and flagged as an error. -The operators and their precedence, associativity, and values -are the same as in the C language. -The following list of operators is grouped into levels of -equal-precedence operators. -The levels are listed in order of decreasing precedence. -</P><P> - -<DL COMPACT> - -<DT><CODE><VAR>id</VAR>++ <VAR>id</VAR>--</CODE> -<DD>variable post-increment and post-decrement -<P> - -<DT><CODE>++<VAR>id</VAR> --<VAR>id</VAR></CODE> -<DD>variable pre-increment and pre-decrement -<P> - -<DT><CODE>- +</CODE> -<DD>unary minus and plus -<P> - -<DT><CODE>! ~</CODE> -<DD>logical and bitwise negation -<P> - -<DT><CODE>**</CODE> -<DD>exponentiation -<P> - -<DT><CODE>* / %</CODE> -<DD>multiplication, division, remainder -<P> - -<DT><CODE>+ -</CODE> -<DD>addition, subtraction -<P> - -<DT><CODE><< >></CODE> -<DD>left and right bitwise shifts -<P> - -<DT><CODE><= >= < ></CODE> -<DD>comparison -<P> - -<DT><CODE>== !=</CODE> -<DD>equality and inequality -<P> - -<DT><CODE>&</CODE> -<DD>bitwise AND -<P> - -<DT><CODE>^</CODE> -<DD>bitwise exclusive OR -<P> - -<DT><CODE>|</CODE> -<DD>bitwise OR -<P> - -<DT><CODE>&&</CODE> -<DD>logical AND -<P> - -<DT><CODE>||</CODE> -<DD>logical OR -<P> - -<DT><CODE>expr ? expr : expr</CODE> -<DD>conditional operator -<P> - -<DT><CODE>= *= /= %= += -= <<= >>= &= ^= |=</CODE> -<DD>assignment -<P> - -<DT><CODE>expr1 , expr2</CODE> -<DD>comma -</DL> -<P> - -Shell variables are allowed as operands; parameter expansion is -performed before the expression is evaluated. -Within an expression, shell variables may also be referenced by name -without using the parameter expansion syntax. -A shell variable that is null or unset evaluates to 0 when referenced -by name without using the parameter expansion syntax. -The value of a variable is evaluated as an arithmetic expression -when it is referenced, or when a variable which has been given the -<VAR>integer</VAR> attribute using <SAMP>`declare -i'</SAMP> is assigned a value. -A null value evaluates to 0. -A shell variable need not have its integer attribute turned on -to be used in an expression. -</P><P> - -Constants with a leading 0 are interpreted as octal numbers. -A leading <SAMP>`0x'</SAMP> or <SAMP>`0X'</SAMP> denotes hexadecimal. Otherwise, -numbers take the form [<VAR>base</VAR><CODE>#</CODE>]<VAR>n</VAR>, where <VAR>base</VAR> -is a decimal number between 2 and 64 representing the arithmetic -base, and <VAR>n</VAR> is a number in that base. If <VAR>base</VAR><CODE>#</CODE> is -omitted, then base 10 is used. -The digits greater than 9 are represented by the lowercase letters, -the uppercase letters, <SAMP>`@'</SAMP>, and <SAMP>`_'</SAMP>, in that order. -If <VAR>base</VAR> is less than or equal to 36, lowercase and uppercase -letters may be used interchangeably to represent numbers between 10 -and 35. -</P><P> - -Operators are evaluated in order of precedence. Sub-expressions in -parentheses are evaluated first and may override the precedence -rules above. -</P><P> - -<A NAME="Aliases"></A> -<HR SIZE="6"> -<A NAME="SEC82"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC81"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC83"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC83"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.6 Aliases </H2> -<!--docid::SEC82::--> -<P> - -<VAR>Aliases</VAR> allow a string to be substituted for a word when it is used -as the first word of a simple command. -The shell maintains a list of aliases that may be set and unset with -the <CODE>alias</CODE> and <CODE>unalias</CODE> builtin commands. -</P><P> - -The first word of each simple command, if unquoted, is checked to see -if it has an alias. -If so, that word is replaced by the text of the alias. -The characters <SAMP>`/'</SAMP>, <SAMP>`$'</SAMP>, <SAMP>``'</SAMP>, <SAMP>`='</SAMP> and any of the -shell metacharacters or quoting characters listed above may not appear -in an alias name. -The replacement text may contain any valid -shell input, including shell metacharacters. -The first word of the replacement text is tested for -aliases, but a word that is identical to an alias being expanded -is not expanded a second time. -This means that one may alias <CODE>ls</CODE> to <CODE>"ls -F"</CODE>, -for instance, and Bash does not try to recursively expand the -replacement text. If the last character of the alias value is a -space or tab character, then the next command word following the -alias is also checked for alias expansion. -</P><P> - -Aliases are created and listed with the <CODE>alias</CODE> -command, and removed with the <CODE>unalias</CODE> command. -</P><P> - -There is no mechanism for using arguments in the replacement text, -as in <CODE>csh</CODE>. -If arguments are needed, a shell function should be used -(see section <A HREF="b.html#SEC23">3.3 Shell Functions</A>). -</P><P> - -Aliases are not expanded when the shell is not interactive, -unless the <CODE>expand_aliases</CODE> shell option is set using -<CODE>shopt</CODE> (see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>). -</P><P> - -The rules concerning the definition and use of aliases are -somewhat confusing. Bash -always reads at least one complete line -of input before executing any -of the commands on that line. Aliases are expanded when a -command is read, not when it is executed. Therefore, an -alias definition appearing on the same line as another -command does not take effect until the next line of input is read. -The commands following the alias definition -on that line are not affected by the new alias. -This behavior is also an issue when functions are executed. -Aliases are expanded when a function definition is read, -not when the function is executed, because a function definition -is itself a compound command. As a consequence, aliases -defined in a function are not available until after that -function is executed. To be safe, always put -alias definitions on a separate line, and do not use <CODE>alias</CODE> -in compound commands. -</P><P> - -For almost every purpose, shell functions are preferred over aliases. -</P><P> - -<A NAME="Arrays"></A> -<HR SIZE="6"> -<A NAME="SEC83"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC82"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC84"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC84"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.7 Arrays </H2> -<!--docid::SEC83::--> -<P> - -Bash provides one-dimensional array variables. Any variable may be used as -an array; the <CODE>declare</CODE> builtin will explicitly declare an array. -There is no maximum -limit on the size of an array, nor any requirement that members -be indexed or assigned contiguously. Arrays are zero-based. -</P><P> - -An array is created automatically if any variable is assigned to using -the syntax -<TABLE><tr><td> </td><td class=example><pre>name[<VAR>subscript</VAR>]=<VAR>value</VAR> -</pre></td></tr></table></P><P> - -The <VAR>subscript</VAR> -is treated as an arithmetic expression that must evaluate to a number -greater than or equal to zero. To explicitly declare an array, use -<TABLE><tr><td> </td><td class=example><pre>declare -a <VAR>name</VAR> -</pre></td></tr></table>The syntax -<TABLE><tr><td> </td><td class=example><pre>declare -a <VAR>name</VAR>[<VAR>subscript</VAR>] -</pre></td></tr></table>is also accepted; the <VAR>subscript</VAR> is ignored. Attributes may be -specified for an array variable using the <CODE>declare</CODE> and -<CODE>readonly</CODE> builtins. Each attribute applies to all members of -an array. -</P><P> - -Arrays are assigned to using compound assignments of the form -<TABLE><tr><td> </td><td class=example><pre>name=(value<VAR>1</VAR> <small>...</small> value<VAR>n</VAR>) -</pre></td></tr></table>where each -<VAR>value</VAR> is of the form <CODE>[[<VAR>subscript</VAR>]=]</CODE><VAR>string</VAR>. If -the optional subscript is supplied, that index is assigned to; -otherwise the index of the element assigned is the last index assigned -to by the statement plus one. Indexing starts at zero. -This syntax is also accepted by the <CODE>declare</CODE> -builtin. Individual array elements may be assigned to using the -<CODE>name[</CODE><VAR>subscript</VAR><CODE>]=</CODE><VAR>value</VAR> syntax introduced above. -</P><P> - -Any element of an array may be referenced using -<CODE>${name[</CODE><VAR>subscript</VAR><CODE>]}</CODE>. -The braces are required to avoid -conflicts with the shell's filename expansion operators. If the -<VAR>subscript</VAR> is <SAMP>`@'</SAMP> or <SAMP>`*'</SAMP>, the word expands to all members -of the array <VAR>name</VAR>. These subscripts differ only when the word -appears within double quotes. -If the word is double-quoted, -<CODE>${name[*]}</CODE> expands to a single word with -the value of each array member separated by the first character of the -<CODE>IFS</CODE> variable, and <CODE>${name[@]}</CODE> expands each element of -<VAR>name</VAR> to a separate word. When there are no array members, -<CODE>${name[@]}</CODE> expands to nothing. -If the double-quoted expansion occurs within a word, the expansion of -the first parameter is joined with the beginning part of the original -word, and the expansion of the last parameter is joined with the last -part of the original word. -This is analogous to the -expansion of the special parameters <SAMP>`@'</SAMP> and <SAMP>`*'</SAMP>. -<CODE>${#name[</CODE><VAR>subscript</VAR><CODE>]}</CODE> expands to the length of -<CODE>${name[</CODE><VAR>subscript</VAR><CODE>]}</CODE>. -If <VAR>subscript</VAR> is <SAMP>`@'</SAMP> or -<SAMP>`*'</SAMP>, the expansion is the number of elements in the array. -Referencing an array variable without a subscript is equivalent to -referencing element zero. -</P><P> - -The <CODE>unset</CODE> builtin is used to destroy arrays. -<CODE>unset</CODE> <VAR>name</VAR>[<VAR>subscript</VAR>] -destroys the array element at index <VAR>subscript</VAR>. -Care must be taken to avoid unwanted side effects caused by filename -generation. -<CODE>unset</CODE> <VAR>name</VAR>, where <VAR>name</VAR> is an array, removes the -entire array. A subscript of <SAMP>`*'</SAMP> or <SAMP>`@'</SAMP> also removes the -entire array. -</P><P> - -The <CODE>declare</CODE>, <CODE>local</CODE>, and <CODE>readonly</CODE> -builtins each accept a <SAMP>`-a'</SAMP> -option to specify an array. The <CODE>read</CODE> -builtin accepts a <SAMP>`-a'</SAMP> -option to assign a list of words read from the standard input -to an array, and can read values from the standard input into -individual array elements. The <CODE>set</CODE> and <CODE>declare</CODE> -builtins display array values in a way that allows them to be -reused as input. -</P><P> - -<A NAME="The Directory Stack"></A> -<HR SIZE="6"> -<A NAME="SEC84"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC83"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC85"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC86"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC86"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.8 The Directory Stack </H2> -<!--docid::SEC84::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC85">6.8.1 Directory Stack Builtins</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Bash builtin commands to manipulate - the directory stack.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -The directory stack is a list of recently-visited directories. The -<CODE>pushd</CODE> builtin adds directories to the stack as it changes -the current directory, and the <CODE>popd</CODE> builtin removes specified -directories from the stack and changes the current directory to -the directory removed. The <CODE>dirs</CODE> builtin displays the contents -of the directory stack. -</P><P> - -The contents of the directory stack are also visible -as the value of the <CODE>DIRSTACK</CODE> shell variable. -</P><P> - -<A NAME="Directory Stack Builtins"></A> -<HR SIZE="6"> -<A NAME="SEC85"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC84"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC86"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC86"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC84"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC86"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 6.8.1 Directory Stack Builtins </H3> -<!--docid::SEC85::--> -<P> - -<DL COMPACT> - -<DT><CODE>dirs</CODE> -<DD><A NAME="IDX278"></A> -<TABLE><tr><td> </td><td class=example><pre>dirs [+<VAR>N</VAR> | -<VAR>N</VAR>] [-clpv] -</pre></td></tr></table>Display the list of currently remembered directories. Directories -are added to the list with the <CODE>pushd</CODE> command; the -<CODE>popd</CODE> command removes directories from the list. -<DL COMPACT> -<DT><CODE>+<VAR>N</VAR></CODE> -<DD>Displays the <VAR>N</VAR>th directory (counting from the left of the -list printed by <CODE>dirs</CODE> when invoked without options), starting -with zero. -<DT><CODE>-<VAR>N</VAR></CODE> -<DD>Displays the <VAR>N</VAR>th directory (counting from the right of the -list printed by <CODE>dirs</CODE> when invoked without options), starting -with zero. -<DT><CODE>-c</CODE> -<DD>Clears the directory stack by deleting all of the elements. -<DT><CODE>-l</CODE> -<DD>Produces a longer listing; the default listing format uses a -tilde to denote the home directory. -<DT><CODE>-p</CODE> -<DD>Causes <CODE>dirs</CODE> to print the directory stack with one entry per -line. -<DT><CODE>-v</CODE> -<DD>Causes <CODE>dirs</CODE> to print the directory stack with one entry per -line, prefixing each entry with its index in the stack. -</DL> -<P> - -<DT><CODE>popd</CODE> -<DD><A NAME="IDX279"></A> -<TABLE><tr><td> </td><td class=example><pre>popd [+<VAR>N</VAR> | -<VAR>N</VAR>] [-n] -</pre></td></tr></table><P> - -Remove the top entry from the directory stack, and <CODE>cd</CODE> -to the new top directory. -When no arguments are given, <CODE>popd</CODE> -removes the top directory from the stack and -performs a <CODE>cd</CODE> to the new top directory. The -elements are numbered from 0 starting at the first directory listed with -<CODE>dirs</CODE>; i.e., <CODE>popd</CODE> is equivalent to <CODE>popd +0</CODE>. -<DL COMPACT> -<DT><CODE>+<VAR>N</VAR></CODE> -<DD>Removes the <VAR>N</VAR>th directory (counting from the left of the -list printed by <CODE>dirs</CODE>), starting with zero. -<DT><CODE>-<VAR>N</VAR></CODE> -<DD>Removes the <VAR>N</VAR>th directory (counting from the right of the -list printed by <CODE>dirs</CODE>), starting with zero. -<DT><CODE>-n</CODE> -<DD>Suppresses the normal change of directory when removing directories -from the stack, so that only the stack is manipulated. -</DL> -<P> - -<A NAME="IDX280"></A> -<DT><CODE>pushd</CODE> -<DD><TABLE><tr><td> </td><td class=example><pre>pushd [-n] [<VAR>+N</VAR> | <VAR>-N</VAR> | <VAR>dir</VAR> ] -</pre></td></tr></table><P> - -Save the current directory on the top of the directory stack -and then <CODE>cd</CODE> to <VAR>dir</VAR>. -With no arguments, <CODE>pushd</CODE> exchanges the top two directories. -</P><P> - -<DL COMPACT> -<DT><CODE>-n</CODE> -<DD>Suppresses the normal change of directory when adding directories -to the stack, so that only the stack is manipulated. -<DT><CODE>+<VAR>N</VAR></CODE> -<DD>Brings the <VAR>N</VAR>th directory (counting from the left of the -list printed by <CODE>dirs</CODE>, starting with zero) to the top of -the list by rotating the stack. -<DT><CODE>-<VAR>N</VAR></CODE> -<DD>Brings the <VAR>N</VAR>th directory (counting from the right of the -list printed by <CODE>dirs</CODE>, starting with zero) to the top of -the list by rotating the stack. -<DT><CODE><VAR>dir</VAR></CODE> -<DD>Makes the current working directory be the top of the stack, and then -executes the equivalent of `<CODE>cd</CODE> <VAR>dir</VAR>'. -<CODE>cd</CODE>s to <VAR>dir</VAR>. -</DL> -<P> - -</DL> -<P> - -<A NAME="Printing a Prompt"></A> -<HR SIZE="6"> -<A NAME="SEC86"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC85"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC87"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.9 Controlling the Prompt </H2> -<!--docid::SEC86::--> -<P> - -The value of the variable <CODE>PROMPT_COMMAND</CODE> is examined just before -Bash prints each primary prompt. If <CODE>PROMPT_COMMAND</CODE> is set and -has a non-null value, then the -value is executed just as if it had been typed on the command line. -</P><P> - -In addition, the following table describes the special characters which -can appear in the prompt variables: -</P><P> - -<DL COMPACT> -<DT><CODE>\a</CODE> -<DD>A bell character. -<DT><CODE>\d</CODE> -<DD>The date, in "Weekday Month Date" format (e.g., "Tue May 26"). -<DT><CODE>\D{<VAR>format</VAR>}</CODE> -<DD>The <VAR>format</VAR> is passed to <CODE>strftime</CODE>(3) and the result is inserted -into the prompt string; an empty <VAR>format</VAR> results in a locale-specific -time representation. The braces are required. -<DT><CODE>\e</CODE> -<DD>An escape character. -<DT><CODE>\h</CODE> -<DD>The hostname, up to the first `.'. -<DT><CODE>\H</CODE> -<DD>The hostname. -<DT><CODE>\j</CODE> -<DD>The number of jobs currently managed by the shell. -<DT><CODE>\l</CODE> -<DD>The basename of the shell's terminal device name. -<DT><CODE>\n</CODE> -<DD>A newline. -<DT><CODE>\r</CODE> -<DD>A carriage return. -<DT><CODE>\s</CODE> -<DD>The name of the shell, the basename of <CODE>$0</CODE> (the portion -following the final slash). -<DT><CODE>\t</CODE> -<DD>The time, in 24-hour HH:MM:SS format. -<DT><CODE>\T</CODE> -<DD>The time, in 12-hour HH:MM:SS format. -<DT><CODE>\@</CODE> -<DD>The time, in 12-hour am/pm format. -<DT><CODE>\A</CODE> -<DD>The time, in 24-hour HH:MM format. -<DT><CODE>\u</CODE> -<DD>The username of the current user. -<DT><CODE>\v</CODE> -<DD>The version of Bash (e.g., 2.00) -<DT><CODE>\V</CODE> -<DD>The release of Bash, version + patchlevel (e.g., 2.00.0) -<DT><CODE>\w</CODE> -<DD>The current working directory, with <CODE>$HOME</CODE> abbreviated with a tilde. -<DT><CODE>\W</CODE> -<DD>The basename of <CODE>$PWD</CODE>, with <CODE>$HOME</CODE> abbreviated with a tilde. -<DT><CODE>\!</CODE> -<DD>The history number of this command. -<DT><CODE>\#</CODE> -<DD>The command number of this command. -<DT><CODE>\$</CODE> -<DD>If the effective uid is 0, <CODE>#</CODE>, otherwise <CODE>$</CODE>. -<DT><CODE>\<VAR>nnn</VAR></CODE> -<DD>The character whose ASCII code is the octal value <VAR>nnn</VAR>. -<DT><CODE>\\</CODE> -<DD>A backslash. -<DT><CODE>\[</CODE> -<DD>Begin a sequence of non-printing characters. This could be used to -embed a terminal control sequence into the prompt. -<DT><CODE>\]</CODE> -<DD>End a sequence of non-printing characters. -</DL> -<P> - -The command number and the history number are usually different: -the history number of a command is its position in the history -list, which may include commands restored from the history file -(see section <A HREF="b.html#SEC118">9.1 Bash History Facilities</A>), while the command number is -the position in the sequence of commands executed during the current -shell session. -</P><P> - -After the string is decoded, it is expanded via -parameter expansion, command substitution, arithmetic -expansion, and quote removal, subject to the value of the -<CODE>promptvars</CODE> shell option (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -</P><P> - -<A NAME="The Restricted Shell"></A> -<HR SIZE="6"> -<A NAME="SEC87"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC86"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC88"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC68"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.10 The Restricted Shell </H2> -<!--docid::SEC87::--> -<P> - -If Bash is started with the name <CODE>rbash</CODE>, or the -<SAMP>`--restricted'</SAMP> -or -<SAMP>`-r'</SAMP> -option is supplied at invocation, the shell becomes restricted. -A restricted shell is used to -set up an environment more controlled than the standard shell. -A restricted shell behaves identically to <CODE>bash</CODE> -with the exception that the following are disallowed or not performed: -</P><P> - -<UL> -<LI> -Changing directories with the <CODE>cd</CODE> builtin. -<LI> -Setting or unsetting the values of the <CODE>SHELL</CODE>, <CODE>PATH</CODE>, -<CODE>ENV</CODE>, or <CODE>BASH_ENV</CODE> variables. -<LI> -Specifying command names containing slashes. -<LI> -Specifying a filename containing a slash as an argument to the <CODE>.</CODE> -builtin command. -<LI> -Specifying a filename containing a slash as an argument to the <SAMP>`-p'</SAMP> -option to the <CODE>hash</CODE> builtin command. -<LI> -Importing function definitions from the shell environment at startup. -<LI> -Parsing the value of <CODE>SHELLOPTS</CODE> from the shell environment at startup. -<LI> -Redirecting output using the <SAMP>`>'</SAMP>, <SAMP>`>|'</SAMP>, <SAMP>`<>'</SAMP>, <SAMP>`>&'</SAMP>, -<SAMP>`&>'</SAMP>, and <SAMP>`>>'</SAMP> redirection operators. -<LI> -Using the <CODE>exec</CODE> builtin to replace the shell with another command. -<LI> -Adding or deleting builtin commands with the -<SAMP>`-f'</SAMP> and <SAMP>`-d'</SAMP> options to the <CODE>enable</CODE> builtin. -<LI> -Using the <CODE>enable</CODE> builtin command to enable disabled shell builtins. -<LI> -Specifying the <SAMP>`-p'</SAMP> option to the <CODE>command</CODE> builtin. -<LI> -Turning off restricted mode with <SAMP>`set +r'</SAMP> or <SAMP>`set +o restricted'</SAMP>. -</UL> -<P> - -These restrictions are enforced after any startup files are read. -</P><P> - -When a command that is found to be a shell script is executed -(see section <A HREF="b.html#SEC55">3.8 Shell Scripts</A>), <CODE>rbash</CODE> turns off any restrictions in -the shell spawned to execute the script. -</P><P> - -<A NAME="Bash POSIX Mode"></A> -<HR SIZE="6"> -<A NAME="SEC88"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC87"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC68"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC66"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 6.11 Bash POSIX Mode </H2> -<!--docid::SEC88::--> -<P> - -Starting Bash with the <SAMP>`--posix'</SAMP> command-line option or executing -<SAMP>`set -o posix'</SAMP> while Bash is running will cause Bash to conform more -closely to the POSIX standard by changing the behavior to -match that specified by POSIX in areas where the Bash default differs. -</P><P> - -When invoked as <CODE>sh</CODE>, Bash enters POSIX mode after reading the -startup files. -</P><P> - -The following list is what's changed when `POSIX mode' is in effect: -</P><P> - -<OL> -<LI> -When a command in the hash table no longer exists, Bash will re-search -<CODE>$PATH</CODE> to find the new location. This is also available with -<SAMP>`shopt -s checkhash'</SAMP>. -<P> - -<LI> -The message printed by the job control code and builtins when a job -exits with a non-zero status is `Done(status)'. -<P> - -<LI> -The message printed by the job control code and builtins when a job -is stopped is `Stopped(<VAR>signame</VAR>)', where <VAR>signame</VAR> is, for -example, <CODE>SIGTSTP</CODE>. -<P> - -<LI> -The <CODE>bg</CODE> builtin uses the required format to describe each job placed -in the background, which does not include an indication of whether the job -is the current or previous job. -<P> - -<LI> -Reserved words appearing in a context where reserved words are recognized -do not undergo alias expansion. -<P> - -<LI> -The POSIX <CODE>PS1</CODE> and <CODE>PS2</CODE> expansions of <SAMP>`!'</SAMP> to -the history number and <SAMP>`!!'</SAMP> to <SAMP>`!'</SAMP> are enabled, -and parameter expansion is performed on the values of <CODE>PS1</CODE> and -<CODE>PS2</CODE> regardless of the setting of the <CODE>promptvars</CODE> option. -<P> - -<LI> -The POSIX startup files are executed (<CODE>$ENV</CODE>) rather than -the normal Bash files. -<P> - -<LI> -Tilde expansion is only performed on assignments preceding a command -name, rather than on all assignment statements on the line. -<P> - -<LI> -The default history file is <TT>`~/.sh_history'</TT> (this is the -default value of <CODE>$HISTFILE</CODE>). -<P> - -<LI> -The output of <SAMP>`kill -l'</SAMP> prints all the signal names on a single line, -separated by spaces, without the <SAMP>`SIG'</SAMP> prefix. -<P> - -<LI> -The <CODE>kill</CODE> builtin does not accept signal names with a <SAMP>`SIG'</SAMP> -prefix. -<P> - -<LI> -Non-interactive shells exit if <VAR>filename</VAR> in <CODE>.</CODE> <VAR>filename</VAR> -is not found. -<P> - -<LI> -Non-interactive shells exit if a syntax error in an arithmetic expansion -results in an invalid expression. -<P> - -<LI> -Redirection operators do not perform filename expansion on the word -in the redirection unless the shell is interactive. -<P> - -<LI> -Redirection operators do not perform word splitting on the word in the -redirection. -<P> - -<LI> -Function names must be valid shell <CODE>name</CODE>s. That is, they may not -contain characters other than letters, digits, and underscores, and -may not start with a digit. Declaring a function with an invalid name -causes a fatal syntax error in non-interactive shells. -<P> - -<LI> -POSIX special builtins are found before shell functions -during command lookup. -<P> - -<LI> -If a POSIX special builtin returns an error status, a -non-interactive shell exits. The fatal errors are those listed in -the POSIX standard, and include things like passing incorrect options, -redirection errors, variable assignment errors for assignments preceding -the command name, and so on. -<P> - -<LI> -If <CODE>CDPATH</CODE> is set, the <CODE>cd</CODE> builtin will not implicitly -append the current directory to it. This means that <CODE>cd</CODE> will -fail if no valid directory name can be constructed from -any of the entries in <CODE>$CDPATH</CODE>, even if the a directory with -the same name as the name given as an argument to <CODE>cd</CODE> exists -in the current directory. -<P> - -<LI> -A non-interactive shell exits with an error status if a variable -assignment error occurs when no command name follows the assignment -statements. -A variable assignment error occurs, for example, when trying to assign -a value to a readonly variable. -<P> - -<LI> -A non-interactive shell exits with an error status if the iteration -variable in a <CODE>for</CODE> statement or the selection variable in a -<CODE>select</CODE> statement is a readonly variable. -<P> - -<LI> -Process substitution is not available. -<P> - -<LI> -Assignment statements preceding POSIX special builtins -persist in the shell environment after the builtin completes. -<P> - -<LI> -Assignment statements preceding shell function calls persist in the -shell environment after the function returns, as if a POSIX -special builtin command had been executed. -<P> - -<LI> -The <CODE>export</CODE> and <CODE>readonly</CODE> builtin commands display their -output in the format required by POSIX. -<P> - -<LI> -The <CODE>trap</CODE> builtin displays signal names without the leading -<CODE>SIG</CODE>. -<P> - -<LI> -The <CODE>trap</CODE> builtin doesn't check the first argument for a possible -signal specification and revert the signal handling to the original -disposition if it is, unless that argument consists solely of digits and -is a valid signal number. If users want to reset the handler for a given -signal to the original disposition, they should use <SAMP>`-'</SAMP> as the -first argument. -<P> - -<LI> -The <CODE>.</CODE> and <CODE>source</CODE> builtins do not search the current directory -for the filename argument if it is not found by searching <CODE>PATH</CODE>. -<P> - -<LI> -Subshells spawned to execute command substitutions inherit the value of -the <SAMP>`-e'</SAMP> option from the parent shell. When not in POSIX mode, -Bash clears the <SAMP>`-e'</SAMP> option in such subshells. -<P> - -<LI> -Alias expansion is always enabled, even in non-interactive shells. -<P> - -<LI> -When the <CODE>alias</CODE> builtin displays alias definitions, it does not -display them with a leading <SAMP>`alias '</SAMP> unless the <SAMP>`-p'</SAMP> option -is supplied. -<P> - -<LI> -When the <CODE>set</CODE> builtin is invoked without options, it does not display -shell function names and definitions. -<P> - -<LI> -When the <CODE>set</CODE> builtin is invoked without options, it displays -variable values without quotes, unless they contain shell metacharacters, -even if the result contains nonprinting characters. -<P> - -<LI> -When the <CODE>cd</CODE> builtin is invoked in <VAR>logical</VAR> mode, and the pathname -constructed from <CODE>$PWD</CODE> and the directory name supplied as an argument -does not refer to an existing directory, <CODE>cd</CODE> will fail instead of -falling back to <VAR>physical</VAR> mode. -<P> - -<LI> -When the <CODE>pwd</CODE> builtin is supplied the <SAMP>`-P'</SAMP> option, it resets -<CODE>$PWD</CODE> to a pathname containing no symlinks. -<P> - -<LI> -The <CODE>pwd</CODE> builtin verifies that the value it prints is the same as the -current directory, even if it is not asked to check the file system with the -<SAMP>`-P'</SAMP> option. -<P> - -<LI> -When listing the history, the <CODE>fc</CODE> builtin does not include an -indication of whether or not a history entry has been modified. -<P> - -<LI> -The default editor used by <CODE>fc</CODE> is <CODE>ed</CODE>. -<P> - -<LI> -The <CODE>type</CODE> and <CODE>command</CODE> builtins will not report a non-executable -file as having been found, though the shell will attempt to execute such a -file if it is the only so-named file found in <CODE>$PATH</CODE>. -<P> - -<LI> -The <CODE>vi</CODE> editing mode will invoke the <CODE>vi</CODE> editor directly when -the <SAMP>`v'</SAMP> command is run, instead of checking <CODE>$FCEDIT</CODE> and -<CODE>$EDITOR</CODE>. -<P> - -<LI> -When the <CODE>xpg_echo</CODE> option is enabled, Bash does not attempt to interpret -any arguments to <CODE>echo</CODE> as options. Each argument is displayed, after -escape characters are converted. -<P> - -</OL> -<P> - -There is other POSIX behavior that Bash does not implement by -default even when in POSIX mode. -Specifically: -</P><P> - -<OL> - -<LI> -The <CODE>fc</CODE> builtin checks <CODE>$EDITOR</CODE> as a program to edit history -entries if <CODE>FCEDIT</CODE> is unset, rather than defaulting directly to -<CODE>ed</CODE>. <CODE>fc</CODE> uses <CODE>ed</CODE> if <CODE>EDITOR</CODE> is unset. -<P> - -<LI> -As noted above, Bash requires the <CODE>xpg_echo</CODE> option to be enabled for -the <CODE>echo</CODE> builtin to be fully conformant. -<P> - -</OL> -<P> - -Bash can be configured to be POSIX-conformant by default, by specifying -the <SAMP>`--enable-strict-posix-default'</SAMP> to <CODE>configure</CODE> when building -(see section <A HREF="b.html#SEC132">10.8 Optional Features</A>). -</P><P> - -<A NAME="Job Control"></A> -<HR SIZE="6"> -<A NAME="SEC89"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC88"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC90"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 7. Job Control </H1> -<!--docid::SEC89::--> -<P> - -This chapter discusses what job control is, how it works, and how -Bash allows you to access its facilities. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC90">7.1 Job Control Basics</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How job control works.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Bash builtin commands used to interact - with job control.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC92">7.3 Job Control Variables</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Variables Bash uses to customize job - control.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Job Control Basics"></A> -<HR SIZE="6"> -<A NAME="SEC90"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC91"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 7.1 Job Control Basics </H2> -<!--docid::SEC90::--> -<P> - -Job control -refers to the ability to selectively stop (suspend) -the execution of processes and continue (resume) -their execution at a later point. A user typically employs -this facility via an interactive interface supplied jointly -by the system's terminal driver and Bash. -</P><P> - -The shell associates a <VAR>job</VAR> with each pipeline. It keeps a -table of currently executing jobs, which may be listed with the -<CODE>jobs</CODE> command. When Bash starts a job -asynchronously, it prints a line that looks -like: -<TABLE><tr><td> </td><td class=example><pre>[1] 25647 -</pre></td></tr></table>indicating that this job is job number 1 and that the process ID -of the last process in the pipeline associated with this job is -25647. All of the processes in a single pipeline are members of -the same job. Bash uses the <VAR>job</VAR> abstraction as the -basis for job control. -</P><P> - -To facilitate the implementation of the user interface to job -control, the operating system maintains the notion of a current terminal -process group ID. Members of this process group (processes whose -process group ID is equal to the current terminal process group -ID) receive keyboard-generated signals such as <CODE>SIGINT</CODE>. -These processes are said to be in the foreground. Background -processes are those whose process group ID differs from the -terminal's; such processes are immune to keyboard-generated -signals. Only foreground processes are allowed to read from or -write to the terminal. Background processes which attempt to -read from (write to) the terminal are sent a <CODE>SIGTTIN</CODE> -(<CODE>SIGTTOU</CODE>) signal by the terminal driver, which, unless -caught, suspends the process. -</P><P> - -If the operating system on which Bash is running supports -job control, Bash contains facilities to use it. Typing the -<VAR>suspend</VAR> character (typically <SAMP>`^Z'</SAMP>, Control-Z) while a -process is running causes that process to be stopped and returns -control to Bash. Typing the <VAR>delayed suspend</VAR> character -(typically <SAMP>`^Y'</SAMP>, Control-Y) causes the process to be stopped -when it attempts to read input from the terminal, and control to -be returned to Bash. The user then manipulates the state of -this job, using the <CODE>bg</CODE> command to continue it in the -background, the <CODE>fg</CODE> command to continue it in the -foreground, or the <CODE>kill</CODE> command to kill it. A <SAMP>`^Z'</SAMP> -takes effect immediately, and has the additional side effect of -causing pending output and typeahead to be discarded. -</P><P> - -There are a number of ways to refer to a job in the shell. The -character <SAMP>`%'</SAMP> introduces a job name. -</P><P> - -Job number <CODE>n</CODE> may be referred to as <SAMP>`%n'</SAMP>. -The symbols <SAMP>`%%'</SAMP> and <SAMP>`%+'</SAMP> refer to the shell's notion of the -current job, which is the last job stopped while it was in the foreground -or started in the background. -A single <SAMP>`%'</SAMP> (with no accompanying job specification) also refers -to the current job. -The previous job may be referenced using <SAMP>`%-'</SAMP>. In output -pertaining to jobs (e.g., the output of the <CODE>jobs</CODE> command), -the current job is always flagged with a <SAMP>`+'</SAMP>, and the -previous job with a <SAMP>`-'</SAMP>. -</P><P> - -A job may also be referred to -using a prefix of the name used to start it, or using a substring -that appears in its command line. For example, <SAMP>`%ce'</SAMP> refers -to a stopped <CODE>ce</CODE> job. Using <SAMP>`%?ce'</SAMP>, on the -other hand, refers to any job containing the string <SAMP>`ce'</SAMP> in -its command line. If the prefix or substring matches more than one job, -Bash reports an error. -</P><P> - -Simply naming a job can be used to bring it into the foreground: -<SAMP>`%1'</SAMP> is a synonym for <SAMP>`fg %1'</SAMP>, bringing job 1 from the -background into the foreground. Similarly, <SAMP>`%1 &'</SAMP> resumes -job 1 in the background, equivalent to <SAMP>`bg %1'</SAMP> -</P><P> - -The shell learns immediately whenever a job changes state. -Normally, Bash waits until it is about to print a prompt -before reporting changes in a job's status so as to not interrupt -any other output. -If the <SAMP>`-b'</SAMP> option to the <CODE>set</CODE> builtin is enabled, -Bash reports such changes immediately (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -Any trap on <CODE>SIGCHLD</CODE> is executed for each child process -that exits. -</P><P> - -If an attempt to exit Bash is made while jobs are stopped, (or running, if -the <CODE>checkjobs</CODE> option is enabled -- see <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>), the -shell prints a warning message, and if the <CODE>checkjobs</CODE> option is -enabled, lists the jobs and their statuses. -The <CODE>jobs</CODE> command may then be used to inspect their status. -If a second attempt to exit is made without an intervening command, -Bash does not print another warning, and any stopped jobs are terminated. -</P><P> - -<A NAME="Job Control Builtins"></A> -<HR SIZE="6"> -<A NAME="SEC91"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC90"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC92"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC92"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 7.2 Job Control Builtins </H2> -<!--docid::SEC91::--> -<P> - -<DL COMPACT> - -<DT><CODE>bg</CODE> -<DD><A NAME="IDX281"></A> -<TABLE><tr><td> </td><td class=example><pre>bg [<VAR>jobspec</VAR> <small>...</small>] -</pre></td></tr></table>Resume each suspended job <VAR>jobspec</VAR> in the background, as if it -had been started with <SAMP>`&'</SAMP>. -If <VAR>jobspec</VAR> is not supplied, the current job is used. -The return status is zero unless it is run when job control is not -enabled, or, when run with job control enabled, any -<VAR>jobspec</VAR> was not found or specifies a job -that was started without job control. -<P> - -<DT><CODE>fg</CODE> -<DD><A NAME="IDX282"></A> -<TABLE><tr><td> </td><td class=example><pre>fg [<VAR>jobspec</VAR>] -</pre></td></tr></table>Resume the job <VAR>jobspec</VAR> in the foreground and make it the current job. -If <VAR>jobspec</VAR> is not supplied, the current job is used. -The return status is that of the command placed into the foreground, -or non-zero if run when job control is disabled or, when run with -job control enabled, <VAR>jobspec</VAR> does not specify a valid job or -<VAR>jobspec</VAR> specifies a job that was started without job control. -<P> - -<DT><CODE>jobs</CODE> -<DD><A NAME="IDX283"></A> -<TABLE><tr><td> </td><td class=example><pre>jobs [-lnprs] [<VAR>jobspec</VAR>] -jobs -x <VAR>command</VAR> [<VAR>arguments</VAR>] -</pre></td></tr></table><P> - -The first form lists the active jobs. The options have the -following meanings: -</P><P> - -<DL COMPACT> -<DT><CODE>-l</CODE> -<DD>List process IDs in addition to the normal information. -<P> - -<DT><CODE>-n</CODE> -<DD>Display information only about jobs that have changed status since -the user was last notified of their status. -<P> - -<DT><CODE>-p</CODE> -<DD>List only the process ID of the job's process group leader. -<P> - -<DT><CODE>-r</CODE> -<DD>Restrict output to running jobs. -<P> - -<DT><CODE>-s</CODE> -<DD>Restrict output to stopped jobs. -</DL> -<P> - -If <VAR>jobspec</VAR> is given, -output is restricted to information about that job. -If <VAR>jobspec</VAR> is not supplied, the status of all jobs is -listed. -</P><P> - -If the <SAMP>`-x'</SAMP> option is supplied, <CODE>jobs</CODE> replaces any -<VAR>jobspec</VAR> found in <VAR>command</VAR> or <VAR>arguments</VAR> with the -corresponding process group ID, and executes <VAR>command</VAR>, -passing it <VAR>argument</VAR>s, returning its exit status. -</P><P> - -<DT><CODE>kill</CODE> -<DD><A NAME="IDX284"></A> -<TABLE><tr><td> </td><td class=example><pre>kill [-s <VAR>sigspec</VAR>] [-n <VAR>signum</VAR>] [-<VAR>sigspec</VAR>] <VAR>jobspec</VAR> or <VAR>pid</VAR> -kill -l [<VAR>exit_status</VAR>] -</pre></td></tr></table>Send a signal specified by <VAR>sigspec</VAR> or <VAR>signum</VAR> to the process -named by job specification <VAR>jobspec</VAR> or process ID <VAR>pid</VAR>. -<VAR>sigspec</VAR> is either a case-insensitive signal name such as -<CODE>SIGINT</CODE> (with or without the <CODE>SIG</CODE> prefix) -or a signal number; <VAR>signum</VAR> is a signal number. -If <VAR>sigspec</VAR> and <VAR>signum</VAR> are not present, <CODE>SIGTERM</CODE> is used. -The <SAMP>`-l'</SAMP> option lists the signal names. -If any arguments are supplied when <SAMP>`-l'</SAMP> is given, the names of the -signals corresponding to the arguments are listed, and the return status -is zero. -<VAR>exit_status</VAR> is a number specifying a signal number or the exit -status of a process terminated by a signal. -The return status is zero if at least one signal was successfully sent, -or non-zero if an error occurs or an invalid option is encountered. -<P> - -<DT><CODE>wait</CODE> -<DD><A NAME="IDX285"></A> -<TABLE><tr><td> </td><td class=example><pre>wait [<VAR>jobspec</VAR> or <VAR>pid</VAR> ...] -</pre></td></tr></table>Wait until the child process specified by each process ID <VAR>pid</VAR> -or job specification <VAR>jobspec</VAR> exits and return the exit status of the -last command waited for. -If a job spec is given, all processes in the job are waited for. -If no arguments are given, all currently active child processes are -waited for, and the return status is zero. -If neither <VAR>jobspec</VAR> nor <VAR>pid</VAR> specifies an active child process -of the shell, the return status is 127. -<P> - -<DT><CODE>disown</CODE> -<DD><A NAME="IDX286"></A> -<TABLE><tr><td> </td><td class=example><pre>disown [-ar] [-h] [<VAR>jobspec</VAR> <small>...</small>] -</pre></td></tr></table>Without options, each <VAR>jobspec</VAR> is removed from the table of -active jobs. -If the <SAMP>`-h'</SAMP> option is given, the job is not removed from the table, -but is marked so that <CODE>SIGHUP</CODE> is not sent to the job if the shell -receives a <CODE>SIGHUP</CODE>. -If <VAR>jobspec</VAR> is not present, and neither the <SAMP>`-a'</SAMP> nor <SAMP>`-r'</SAMP> -option is supplied, the current job is used. -If no <VAR>jobspec</VAR> is supplied, the <SAMP>`-a'</SAMP> option means to remove or -mark all jobs; the <SAMP>`-r'</SAMP> option without a <VAR>jobspec</VAR> -argument restricts operation to running jobs. -<P> - -<DT><CODE>suspend</CODE> -<DD><A NAME="IDX287"></A> -<TABLE><tr><td> </td><td class=example><pre>suspend [-f] -</pre></td></tr></table>Suspend the execution of this shell until it receives a -<CODE>SIGCONT</CODE> signal. The <SAMP>`-f'</SAMP> option means to suspend -even if the shell is a login shell. -<P> - -</DL> -<P> - -When job control is not active, the <CODE>kill</CODE> and <CODE>wait</CODE> -builtins do not accept <VAR>jobspec</VAR> arguments. They must be -supplied process IDs. -</P><P> - -<A NAME="Job Control Variables"></A> -<HR SIZE="6"> -<A NAME="SEC92"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC91"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC89"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 7.3 Job Control Variables </H2> -<!--docid::SEC92::--> -<P> - -<DL COMPACT> - -<A NAME="IDX288"></A> -<DT><CODE>auto_resume</CODE> -<DD><A NAME="IDX289"></A> -This variable controls how the shell interacts with the user and -job control. If this variable exists then single word simple -commands without redirections are treated as candidates for resumption -of an existing job. There is no ambiguity allowed; if there is -more than one job beginning with the string typed, then -the most recently accessed job will be selected. -The name of a stopped job, in this context, is the command line -used to start it. If this variable is set to the value <SAMP>`exact'</SAMP>, -the string supplied must match the name of a stopped job exactly; -if set to <SAMP>`substring'</SAMP>, -the string supplied needs to match a substring of the name of a -stopped job. The <SAMP>`substring'</SAMP> value provides functionality -analogous to the <SAMP>`%?'</SAMP> job ID (see section <A HREF="b.html#SEC90">7.1 Job Control Basics</A>). -If set to any other value, the supplied string must -be a prefix of a stopped job's name; this provides functionality -analogous to the <SAMP>`%'</SAMP> job ID. -<P> - -</DL> -<P> - -<A NAME="IDX290"></A> -</P><P> - -<A NAME="Command Line Editing"></A> -<HR SIZE="6"> -<A NAME="SEC93"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC92"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC94"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 8. Command Line Editing </H1> -<!--docid::SEC93::--> -<P> - -This chapter describes the basic features of the GNU -command line editing interface. -Command line editing is provided by the Readline library, which is -used by several different programs, including Bash. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC94">8.1 Introduction to Line Editing</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Notation used in this text.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC95">8.2 Readline Interaction</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The minimum set of commands for editing a line.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC101">8.3 Readline Init File</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Customizing Readline from a user's view.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC105">8.4 Bindable Readline Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A description of most of the Readline commands - available for binding</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC114">8.5 Readline vi Mode</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">A short description of how to make Readline - behave like the vi editor.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC115">8.6 Programmable Completion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to specify the possible completions for - a specific command.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Builtin commands to specify how to - complete arguments for a particular command.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Introduction and Notation"></A> -<HR SIZE="6"> -<A NAME="SEC94"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC95"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 8.1 Introduction to Line Editing </H2> -<!--docid::SEC94::--> -<P> - -The following paragraphs describe the notation used to represent -keystrokes. -</P><P> - -The text <KBD>C-k</KBD> is read as `Control-K' and describes the character -produced when the <KBD>k</KBD> key is pressed while the Control key -is depressed. -</P><P> - -The text <KBD>M-k</KBD> is read as `Meta-K' and describes the character -produced when the Meta key (if you have one) is depressed, and the <KBD>k</KBD> -key is pressed. -The Meta key is labeled <KBD>ALT</KBD> on many keyboards. -On keyboards with two keys labeled <KBD>ALT</KBD> (usually to either side of -the space bar), the <KBD>ALT</KBD> on the left side is generally set to -work as a Meta key. -The <KBD>ALT</KBD> key on the right may also be configured to work as a -Meta key or may be configured as some other modifier, such as a -Compose key for typing accented characters. -</P><P> - -If you do not have a Meta or <KBD>ALT</KBD> key, or another key working as -a Meta key, the identical keystroke can be generated by typing <KBD>ESC</KBD> -<EM>first</EM>, and then typing <KBD>k</KBD>. -Either process is known as <EM>metafying</EM> the <KBD>k</KBD> key. -</P><P> - -The text <KBD>M-C-k</KBD> is read as `Meta-Control-k' and describes the -character produced by <EM>metafying</EM> <KBD>C-k</KBD>. -</P><P> - -In addition, several keys have their own names. Specifically, -<KBD>DEL</KBD>, <KBD>ESC</KBD>, <KBD>LFD</KBD>, <KBD>SPC</KBD>, <KBD>RET</KBD>, and <KBD>TAB</KBD> all -stand for themselves when seen in this text, or in an init file -(see section <A HREF="b.html#SEC101">8.3 Readline Init File</A>). -If your keyboard lacks a <KBD>LFD</KBD> key, typing <KBD>C-j</KBD> will -produce the desired character. -The <KBD>RET</KBD> key may be labeled <KBD>Return</KBD> or <KBD>Enter</KBD> on -some keyboards. -</P><P> - -<A NAME="Readline Interaction"></A> -<HR SIZE="6"> -<A NAME="SEC95"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC94"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC96"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 8.2 Readline Interaction </H2> -<!--docid::SEC95::--> -<P> - -Often during an interactive session you type in a long line of text, -only to notice that the first word on the line is misspelled. The -Readline library gives you a set of commands for manipulating the text -as you type it in, allowing you to just fix your typo, and not forcing -you to retype the majority of the line. Using these editing commands, -you move the cursor to the place that needs correction, and delete or -insert the text of the corrections. Then, when you are satisfied with -the line, you simply press <KBD>RET</KBD>. You do not have to be at the -end of the line to press <KBD>RET</KBD>; the entire line is accepted -regardless of the location of the cursor within the line. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC96">8.2.1 Readline Bare Essentials</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The least you need to know about Readline.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC97">8.2.2 Readline Movement Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Moving about the input line.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC98">8.2.3 Readline Killing Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to delete text, and how to get it back!</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC99">8.2.4 Readline Arguments</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Giving numeric arguments to commands.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC100">8.2.5 Searching for Commands in the History</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Searching through previous lines.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Readline Bare Essentials"></A> -<HR SIZE="6"> -<A NAME="SEC96"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC95"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC97"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC95"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.2.1 Readline Bare Essentials </H3> -<!--docid::SEC96::--> -<P> - -In order to enter characters into the line, simply type them. The typed -character appears where the cursor was, and then the cursor moves one -space to the right. If you mistype a character, you can use your -erase character to back up and delete the mistyped character. -</P><P> - -Sometimes you may mistype a character, and -not notice the error until you have typed several other characters. In -that case, you can type <KBD>C-b</KBD> to move the cursor to the left, and then -correct your mistake. Afterwards, you can move the cursor to the right -with <KBD>C-f</KBD>. -</P><P> - -When you add text in the middle of a line, you will notice that characters -to the right of the cursor are `pushed over' to make room for the text -that you have inserted. Likewise, when you delete text behind the cursor, -characters to the right of the cursor are `pulled back' to fill in the -blank space created by the removal of the text. A list of the bare -essentials for editing the text of an input line follows. -</P><P> - -<DL COMPACT> -<DT><KBD>C-b</KBD> -<DD>Move back one character. -<DT><KBD>C-f</KBD> -<DD>Move forward one character. -<DT><KBD>DEL</KBD> or <KBD>Backspace</KBD> -<DD>Delete the character to the left of the cursor. -<DT><KBD>C-d</KBD> -<DD>Delete the character underneath the cursor. -<DT>Printing characters -<DD>Insert the character into the line at the cursor. -<DT><KBD>C-_</KBD> or <KBD>C-x C-u</KBD> -<DD>Undo the last editing command. You can undo all the way back to an -empty line. -</DL> -<P> - -(Depending on your configuration, the <KBD>Backspace</KBD> key be set to -delete the character to the left of the cursor and the <KBD>DEL</KBD> key set -to delete the character underneath the cursor, like <KBD>C-d</KBD>, rather -than the character to the left of the cursor.) -</P><P> - -<A NAME="Readline Movement Commands"></A> -<HR SIZE="6"> -<A NAME="SEC97"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC96"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC98"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC98"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC95"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.2.2 Readline Movement Commands </H3> -<!--docid::SEC97::--> -<P> - -The above table describes the most basic keystrokes that you need -in order to do editing of the input line. For your convenience, many -other commands have been added in addition to <KBD>C-b</KBD>, <KBD>C-f</KBD>, -<KBD>C-d</KBD>, and <KBD>DEL</KBD>. Here are some commands for moving more rapidly -about the line. -</P><P> - -<DL COMPACT> -<DT><KBD>C-a</KBD> -<DD>Move to the start of the line. -<DT><KBD>C-e</KBD> -<DD>Move to the end of the line. -<DT><KBD>M-f</KBD> -<DD>Move forward a word, where a word is composed of letters and digits. -<DT><KBD>M-b</KBD> -<DD>Move backward a word. -<DT><KBD>C-l</KBD> -<DD>Clear the screen, reprinting the current line at the top. -</DL> -<P> - -Notice how <KBD>C-f</KBD> moves forward a character, while <KBD>M-f</KBD> moves -forward a word. It is a loose convention that control keystrokes -operate on characters while meta keystrokes operate on words. -</P><P> - -<A NAME="Readline Killing Commands"></A> -<HR SIZE="6"> -<A NAME="SEC98"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC97"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC99"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC99"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC95"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.2.3 Readline Killing Commands </H3> -<!--docid::SEC98::--> -<P> - -<A NAME="IDX291"></A> -<A NAME="IDX292"></A> -</P><P> - -<EM>Killing</EM> text means to delete the text from the line, but to save -it away for later use, usually by <EM>yanking</EM> (re-inserting) -it back into the line. -(`Cut' and `paste' are more recent jargon for `kill' and `yank'.) -</P><P> - -If the description for a command says that it `kills' text, then you can -be sure that you can get the text back in a different (or the same) -place later. -</P><P> - -When you use a kill command, the text is saved in a <EM>kill-ring</EM>. -Any number of consecutive kills save all of the killed text together, so -that when you yank it back, you get it all. The kill -ring is not line specific; the text that you killed on a previously -typed line is available to be yanked back later, when you are typing -another line. -<A NAME="IDX293"></A> -</P><P> - -Here is the list of commands for killing text. -</P><P> - -<DL COMPACT> -<DT><KBD>C-k</KBD> -<DD>Kill the text from the current cursor position to the end of the line. -<P> - -<DT><KBD>M-d</KBD> -<DD>Kill from the cursor to the end of the current word, or, if between -words, to the end of the next word. -Word boundaries are the same as those used by <KBD>M-f</KBD>. -<P> - -<DT><KBD>M-<KBD>DEL</KBD></KBD> -<DD>Kill from the cursor the start of the current word, or, if between -words, to the start of the previous word. -Word boundaries are the same as those used by <KBD>M-b</KBD>. -<P> - -<DT><KBD>C-w</KBD> -<DD>Kill from the cursor to the previous whitespace. This is different than -<KBD>M-<KBD>DEL</KBD></KBD> because the word boundaries differ. -<P> - -</DL> -<P> - -Here is how to <EM>yank</EM> the text back into the line. Yanking -means to copy the most-recently-killed text from the kill buffer. -</P><P> - -<DL COMPACT> -<DT><KBD>C-y</KBD> -<DD>Yank the most recently killed text back into the buffer at the cursor. -<P> - -<DT><KBD>M-y</KBD> -<DD>Rotate the kill-ring, and yank the new top. You can only do this if -the prior command is <KBD>C-y</KBD> or <KBD>M-y</KBD>. -</DL> -<P> - -<A NAME="Readline Arguments"></A> -<HR SIZE="6"> -<A NAME="SEC99"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC98"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC100"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC100"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC95"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.2.4 Readline Arguments </H3> -<!--docid::SEC99::--> -<P> - -You can pass numeric arguments to Readline commands. Sometimes the -argument acts as a repeat count, other times it is the <I>sign</I> of the -argument that is significant. If you pass a negative argument to a -command which normally acts in a forward direction, that command will -act in a backward direction. For example, to kill text back to the -start of the line, you might type <SAMP>`M-- C-k'</SAMP>. -</P><P> - -The general way to pass numeric arguments to a command is to type meta -digits before the command. If the first `digit' typed is a minus -sign (<SAMP>`-'</SAMP>), then the sign of the argument will be negative. Once -you have typed one meta digit to get the argument started, you can type -the remainder of the digits, and then the command. For example, to give -the <KBD>C-d</KBD> command an argument of 10, you could type <SAMP>`M-1 0 C-d'</SAMP>, -which will delete the next ten characters on the input line. -</P><P> - -<A NAME="Searching"></A> -<HR SIZE="6"> -<A NAME="SEC100"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC99"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC95"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.2.5 Searching for Commands in the History </H3> -<!--docid::SEC100::--> -<P> - -Readline provides commands for searching through the command history -(see section <A HREF="b.html#SEC118">9.1 Bash History Facilities</A>) -for lines containing a specified string. -There are two search modes: <EM>incremental</EM> and <EM>non-incremental</EM>. -</P><P> - -Incremental searches begin before the user has finished typing the -search string. -As each character of the search string is typed, Readline displays -the next entry from the history matching the string typed so far. -An incremental search requires only as many characters as needed to -find the desired history entry. -To search backward in the history for a particular string, type -<KBD>C-r</KBD>. Typing <KBD>C-s</KBD> searches forward through the history. -The characters present in the value of the <CODE>isearch-terminators</CODE> variable -are used to terminate an incremental search. -If that variable has not been assigned a value, the <KBD>ESC</KBD> and -<KBD>C-J</KBD> characters will terminate an incremental search. -<KBD>C-g</KBD> will abort an incremental search and restore the original line. -When the search is terminated, the history entry containing the -search string becomes the current line. -</P><P> - -To find other matching entries in the history list, type <KBD>C-r</KBD> or -<KBD>C-s</KBD> as appropriate. -This will search backward or forward in the history for the next -entry matching the search string typed so far. -Any other key sequence bound to a Readline command will terminate -the search and execute that command. -For instance, a <KBD>RET</KBD> will terminate the search and accept -the line, thereby executing the command from the history list. -A movement command will terminate the search, make the last line found -the current line, and begin editing. -</P><P> - -Readline remembers the last incremental search string. If two -<KBD>C-r</KBD>s are typed without any intervening characters defining a new -search string, any remembered search string is used. -</P><P> - -Non-incremental searches read the entire search string before starting -to search for matching history lines. The search string may be -typed by the user or be part of the contents of the current line. -</P><P> - -<A NAME="Readline Init File"></A> -<HR SIZE="6"> -<A NAME="SEC101"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC100"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC102"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 8.3 Readline Init File </H2> -<!--docid::SEC101::--> -<P> - -Although the Readline library comes with a set of Emacs-like -keybindings installed by default, it is possible to use a different set -of keybindings. -Any user can customize programs that use Readline by putting -commands in an <EM>inputrc</EM> file, conventionally in his home directory. -The name of this -file is taken from the value of the shell variable <CODE>INPUTRC</CODE>. If -that variable is unset, the default is <TT>`~/.inputrc'</TT>. If that -file does not exist or cannot be read, the ultimate default is -<TT>`/etc/inputrc'</TT>. -</P><P> - -When a program which uses the Readline library starts up, the -init file is read, and the key bindings are set. -</P><P> - -In addition, the <CODE>C-x C-r</CODE> command re-reads this init file, thus -incorporating any changes that you might have made to it. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Syntax for the commands in the inputrc file.</TD></TR> -</TABLE> - -<br> -<TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC103">8.3.2 Conditional Init Constructs</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Conditional key bindings in the inputrc file.</TD></TR> -</TABLE> - -<br> -<TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC104">8.3.3 Sample Init File</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">An example inputrc file.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Readline Init File Syntax"></A> -<HR SIZE="6"> -<A NAME="SEC102"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC103"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.3.1 Readline Init File Syntax </H3> -<!--docid::SEC102::--> -<P> - -There are only a few basic constructs allowed in the -Readline init file. Blank lines are ignored. -Lines beginning with a <SAMP>`#'</SAMP> are comments. -Lines beginning with a <SAMP>`$'</SAMP> indicate conditional -constructs (see section <A HREF="b.html#SEC103">8.3.2 Conditional Init Constructs</A>). Other lines -denote variable settings and key bindings. -</P><P> - -<DL COMPACT> -<DT>Variable Settings -<DD>You can modify the run-time behavior of Readline by -altering the values of variables in Readline -using the <CODE>set</CODE> command within the init file. -The syntax is simple: -<P> - -<TABLE><tr><td> </td><td class=example><pre>set <VAR>variable</VAR> <VAR>value</VAR> -</pre></td></tr></table></P><P> - -Here, for example, is how to -change from the default Emacs-like key binding to use -<CODE>vi</CODE> line editing commands: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>set editing-mode vi -</pre></td></tr></table></P><P> - -Variable names and values, where appropriate, are recognized without regard -to case. Unrecognized variable names are ignored. -</P><P> - -Boolean variables (those that can be set to on or off) are set to on if -the value is null or empty, <VAR>on</VAR> (case-insensitive), or 1. Any other -value results in the variable being set to off. -</P><P> - -The <CODE>bind -V</CODE> command lists the current Readline variable names -and values. See section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>. -</P><P> - -A great deal of run-time behavior is changeable with the following -variables. -</P><P> - -<A NAME="IDX294"></A> -<DL COMPACT> - -<DT><CODE>bell-style</CODE> -<DD><A NAME="IDX295"></A> -Controls what happens when Readline wants to ring the terminal bell. -If set to <SAMP>`none'</SAMP>, Readline never rings the bell. If set to -<SAMP>`visible'</SAMP>, Readline uses a visible bell if one is available. -If set to <SAMP>`audible'</SAMP> (the default), Readline attempts to ring -the terminal's bell. -<P> - -<DT><CODE>bind-tty-special-chars</CODE> -<DD><A NAME="IDX296"></A> -If set to <SAMP>`on'</SAMP>, Readline attempts to bind the control characters -treated specially by the kernel's terminal driver to their Readline -equivalents. -<P> - -<DT><CODE>comment-begin</CODE> -<DD><A NAME="IDX297"></A> -The string to insert at the beginning of the line when the -<CODE>insert-comment</CODE> command is executed. The default value -is <CODE>"#"</CODE>. -<P> - -<DT><CODE>completion-ignore-case</CODE> -<DD>If set to <SAMP>`on'</SAMP>, Readline performs filename matching and completion -in a case-insensitive fashion. -The default value is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>completion-query-items</CODE> -<DD><A NAME="IDX298"></A> -The number of possible completions that determines when the user is -asked whether the list of possibilities should be displayed. -If the number of possible completions is greater than this value, -Readline will ask the user whether or not he wishes to view -them; otherwise, they are simply listed. -This variable must be set to an integer value greater than or equal to 0. -A negative value means Readline should never ask. -The default limit is <CODE>100</CODE>. -<P> - -<DT><CODE>convert-meta</CODE> -<DD><A NAME="IDX299"></A> -If set to <SAMP>`on'</SAMP>, Readline will convert characters with the -eighth bit set to an ASCII key sequence by stripping the eighth -bit and prefixing an <KBD>ESC</KBD> character, converting them to a -meta-prefixed key sequence. The default value is <SAMP>`on'</SAMP>. -<P> - -<DT><CODE>disable-completion</CODE> -<DD><A NAME="IDX300"></A> -If set to <SAMP>`On'</SAMP>, Readline will inhibit word completion. -Completion characters will be inserted into the line as if they had -been mapped to <CODE>self-insert</CODE>. The default is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>editing-mode</CODE> -<DD><A NAME="IDX301"></A> -The <CODE>editing-mode</CODE> variable controls which default set of -key bindings is used. By default, Readline starts up in Emacs editing -mode, where the keystrokes are most similar to Emacs. This variable can be -set to either <SAMP>`emacs'</SAMP> or <SAMP>`vi'</SAMP>. -<P> - -<DT><CODE>enable-keypad</CODE> -<DD><A NAME="IDX302"></A> -When set to <SAMP>`on'</SAMP>, Readline will try to enable the application -keypad when it is called. Some systems need this to enable the -arrow keys. The default is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>expand-tilde</CODE> -<DD><A NAME="IDX303"></A> -If set to <SAMP>`on'</SAMP>, tilde expansion is performed when Readline -attempts word completion. The default is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>history-preserve-point</CODE> -<DD><A NAME="IDX304"></A> -If set to <SAMP>`on'</SAMP>, the history code attempts to place point at the -same location on each history line retrieved with <CODE>previous-history</CODE> -or <CODE>next-history</CODE>. The default is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>horizontal-scroll-mode</CODE> -<DD><A NAME="IDX305"></A> -This variable can be set to either <SAMP>`on'</SAMP> or <SAMP>`off'</SAMP>. Setting it -to <SAMP>`on'</SAMP> means that the text of the lines being edited will scroll -horizontally on a single screen line when they are longer than the width -of the screen, instead of wrapping onto a new screen line. By default, -this variable is set to <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>input-meta</CODE> -<DD><A NAME="IDX306"></A> -<A NAME="IDX307"></A> -If set to <SAMP>`on'</SAMP>, Readline will enable eight-bit input (it -will not clear the eighth bit in the characters it reads), -regardless of what the terminal claims it can support. The -default value is <SAMP>`off'</SAMP>. The name <CODE>meta-flag</CODE> is a -synonym for this variable. -<P> - -<DT><CODE>isearch-terminators</CODE> -<DD><A NAME="IDX308"></A> -The string of characters that should terminate an incremental search without -subsequently executing the character as a command (see section <A HREF="b.html#SEC100">8.2.5 Searching for Commands in the History</A>). -If this variable has not been given a value, the characters <KBD>ESC</KBD> and -<KBD>C-J</KBD> will terminate an incremental search. -<P> - -<DT><CODE>keymap</CODE> -<DD><A NAME="IDX309"></A> -Sets Readline's idea of the current keymap for key binding commands. -Acceptable <CODE>keymap</CODE> names are -<CODE>emacs</CODE>, -<CODE>emacs-standard</CODE>, -<CODE>emacs-meta</CODE>, -<CODE>emacs-ctlx</CODE>, -<CODE>vi</CODE>, -<CODE>vi-move</CODE>, -<CODE>vi-command</CODE>, and -<CODE>vi-insert</CODE>. -<CODE>vi</CODE> is equivalent to <CODE>vi-command</CODE>; <CODE>emacs</CODE> is -equivalent to <CODE>emacs-standard</CODE>. The default value is <CODE>emacs</CODE>. -The value of the <CODE>editing-mode</CODE> variable also affects the -default keymap. -<P> - -<DT><CODE>mark-directories</CODE> -<DD>If set to <SAMP>`on'</SAMP>, completed directory names have a slash -appended. The default is <SAMP>`on'</SAMP>. -<P> - -<DT><CODE>mark-modified-lines</CODE> -<DD><A NAME="IDX310"></A> -This variable, when set to <SAMP>`on'</SAMP>, causes Readline to display an -asterisk (<SAMP>`*'</SAMP>) at the start of history lines which have been modified. -This variable is <SAMP>`off'</SAMP> by default. -<P> - -<DT><CODE>mark-symlinked-directories</CODE> -<DD><A NAME="IDX311"></A> -If set to <SAMP>`on'</SAMP>, completed names which are symbolic links -to directories have a slash appended (subject to the value of -<CODE>mark-directories</CODE>). -The default is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>match-hidden-files</CODE> -<DD><A NAME="IDX312"></A> -This variable, when set to <SAMP>`on'</SAMP>, causes Readline to match files whose -names begin with a <SAMP>`.'</SAMP> (hidden files) when performing filename -completion, unless the leading <SAMP>`.'</SAMP> is -supplied by the user in the filename to be completed. -This variable is <SAMP>`on'</SAMP> by default. -<P> - -<DT><CODE>output-meta</CODE> -<DD><A NAME="IDX313"></A> -If set to <SAMP>`on'</SAMP>, Readline will display characters with the -eighth bit set directly rather than as a meta-prefixed escape -sequence. The default is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>page-completions</CODE> -<DD><A NAME="IDX314"></A> -If set to <SAMP>`on'</SAMP>, Readline uses an internal <CODE>more</CODE>-like pager -to display a screenful of possible completions at a time. -This variable is <SAMP>`on'</SAMP> by default. -<P> - -<DT><CODE>print-completions-horizontally</CODE> -<DD>If set to <SAMP>`on'</SAMP>, Readline will display completions with matches -sorted horizontally in alphabetical order, rather than down the screen. -The default is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>show-all-if-ambiguous</CODE> -<DD><A NAME="IDX315"></A> -This alters the default behavior of the completion functions. If -set to <SAMP>`on'</SAMP>, -words which have more than one possible completion cause the -matches to be listed immediately instead of ringing the bell. -The default value is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>show-all-if-unmodified</CODE> -<DD><A NAME="IDX316"></A> -This alters the default behavior of the completion functions in -a fashion similar to <VAR>show-all-if-ambiguous</VAR>. -If set to <SAMP>`on'</SAMP>, -words which have more than one possible completion without any -possible partial completion (the possible completions don't share -a common prefix) cause the matches to be listed immediately instead -of ringing the bell. -The default value is <SAMP>`off'</SAMP>. -<P> - -<DT><CODE>visible-stats</CODE> -<DD><A NAME="IDX317"></A> -If set to <SAMP>`on'</SAMP>, a character denoting a file's type -is appended to the filename when listing possible -completions. The default is <SAMP>`off'</SAMP>. -<P> - -</DL> -<P> - -<DT>Key Bindings -<DD>The syntax for controlling key bindings in the init file is -simple. First you need to find the name of the command that you -want to change. The following sections contain tables of the command -name, the default keybinding, if any, and a short description of what -the command does. -<P> - -Once you know the name of the command, simply place on a line -in the init file the name of the key -you wish to bind the command to, a colon, and then the name of the -command. -There can be no space between the key name and the colon -- that will be -interpreted as part of the key name. -The name of the key can be expressed in different ways, depending on -what you find most comfortable. -</P><P> - -In addition to command names, readline allows keys to be bound -to a string that is inserted when the key is pressed (a <VAR>macro</VAR>). -</P><P> - -The <CODE>bind -p</CODE> command displays Readline function names and -bindings in a format that can put directly into an initialization file. -See section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>. -</P><P> - -<DL COMPACT> -<DT><VAR>keyname</VAR>: <VAR>function-name</VAR> or <VAR>macro</VAR> -<DD><VAR>keyname</VAR> is the name of a key spelled out in English. For example: -<TABLE><tr><td> </td><td class=example><pre>Control-u: universal-argument -Meta-Rubout: backward-kill-word -Control-o: "> output" -</pre></td></tr></table><P> - -In the above example, <KBD>C-u</KBD> is bound to the function -<CODE>universal-argument</CODE>, -<KBD>M-DEL</KBD> is bound to the function <CODE>backward-kill-word</CODE>, and -<KBD>C-o</KBD> is bound to run the macro -expressed on the right hand side (that is, to insert the text -<SAMP>`> output'</SAMP> into the line). -</P><P> - -A number of symbolic character names are recognized while -processing this key binding syntax: -<VAR>DEL</VAR>, -<VAR>ESC</VAR>, -<VAR>ESCAPE</VAR>, -<VAR>LFD</VAR>, -<VAR>NEWLINE</VAR>, -<VAR>RET</VAR>, -<VAR>RETURN</VAR>, -<VAR>RUBOUT</VAR>, -<VAR>SPACE</VAR>, -<VAR>SPC</VAR>, -and -<VAR>TAB</VAR>. -</P><P> - -<DT>"<VAR>keyseq</VAR>": <VAR>function-name</VAR> or <VAR>macro</VAR> -<DD><VAR>keyseq</VAR> differs from <VAR>keyname</VAR> above in that strings -denoting an entire key sequence can be specified, by placing -the key sequence in double quotes. Some GNU Emacs style key -escapes can be used, as in the following example, but the -special character names are not recognized. -<P> - -<TABLE><tr><td> </td><td class=example><pre>"\C-u": universal-argument -"\C-x\C-r": re-read-init-file -"\e[11~": "Function Key 1" -</pre></td></tr></table></P><P> - -In the above example, <KBD>C-u</KBD> is again bound to the function -<CODE>universal-argument</CODE> (just as it was in the first example), -<SAMP>`<KBD>C-x</KBD> <KBD>C-r</KBD>'</SAMP> is bound to the function <CODE>re-read-init-file</CODE>, -and <SAMP>`<KBD>ESC</KBD> <KBD>[</KBD> <KBD>1</KBD> <KBD>1</KBD> <KBD>~</KBD>'</SAMP> is bound to insert -the text <SAMP>`Function Key 1'</SAMP>. -</P><P> - -</DL> -<P> - -The following GNU Emacs style escape sequences are available when -specifying key sequences: -</P><P> - -<DL COMPACT> -<DT><CODE><KBD>\C-</KBD></CODE> -<DD>control prefix -<DT><CODE><KBD>\M-</KBD></CODE> -<DD>meta prefix -<DT><CODE><KBD>\e</KBD></CODE> -<DD>an escape character -<DT><CODE><KBD>\\</KBD></CODE> -<DD>backslash -<DT><CODE><KBD>\"</KBD></CODE> -<DD><KBD>"</KBD>, a double quotation mark -<DT><CODE><KBD>\'</KBD></CODE> -<DD><KBD>'</KBD>, a single quote or apostrophe -</DL> -<P> - -In addition to the GNU Emacs style escape sequences, a second -set of backslash escapes is available: -</P><P> - -<DL COMPACT> -<DT><CODE>\a</CODE> -<DD>alert (bell) -<DT><CODE>\b</CODE> -<DD>backspace -<DT><CODE>\d</CODE> -<DD>delete -<DT><CODE>\f</CODE> -<DD>form feed -<DT><CODE>\n</CODE> -<DD>newline -<DT><CODE>\r</CODE> -<DD>carriage return -<DT><CODE>\t</CODE> -<DD>horizontal tab -<DT><CODE>\v</CODE> -<DD>vertical tab -<DT><CODE>\<VAR>nnn</VAR></CODE> -<DD>the eight-bit character whose value is the octal value <VAR>nnn</VAR> -(one to three digits) -<DT><CODE>\x<VAR>HH</VAR></CODE> -<DD>the eight-bit character whose value is the hexadecimal value <VAR>HH</VAR> -(one or two hex digits) -</DL> -<P> - -When entering the text of a macro, single or double quotes must -be used to indicate a macro definition. -Unquoted text is assumed to be a function name. -In the macro body, the backslash escapes described above are expanded. -Backslash will quote any other character in the macro text, -including <SAMP>`"'</SAMP> and <SAMP>`''</SAMP>. -For example, the following binding will make <SAMP>`<KBD>C-x</KBD> \'</SAMP> -insert a single <SAMP>`\'</SAMP> into the line: -<TABLE><tr><td> </td><td class=example><pre>"\C-x\\": "\\" -</pre></td></tr></table></P><P> - -</DL> -<P> - -<A NAME="Conditional Init Constructs"></A> -<HR SIZE="6"> -<A NAME="SEC103"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC102"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC104"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC104"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.3.2 Conditional Init Constructs </H3> -<!--docid::SEC103::--> -<P> - -Readline implements a facility similar in spirit to the conditional -compilation features of the C preprocessor which allows key -bindings and variable settings to be performed as the result -of tests. There are four parser directives used. -</P><P> - -<DL COMPACT> -<DT><CODE>$if</CODE> -<DD>The <CODE>$if</CODE> construct allows bindings to be made based on the -editing mode, the terminal being used, or the application using -Readline. The text of the test extends to the end of the line; -no characters are required to isolate it. -<P> - -<DL COMPACT> -<DT><CODE>mode</CODE> -<DD>The <CODE>mode=</CODE> form of the <CODE>$if</CODE> directive is used to test -whether Readline is in <CODE>emacs</CODE> or <CODE>vi</CODE> mode. -This may be used in conjunction -with the <SAMP>`set keymap'</SAMP> command, for instance, to set bindings in -the <CODE>emacs-standard</CODE> and <CODE>emacs-ctlx</CODE> keymaps only if -Readline is starting out in <CODE>emacs</CODE> mode. -<P> - -<DT><CODE>term</CODE> -<DD>The <CODE>term=</CODE> form may be used to include terminal-specific -key bindings, perhaps to bind the key sequences output by the -terminal's function keys. The word on the right side of the -<SAMP>`='</SAMP> is tested against both the full name of the terminal and -the portion of the terminal name before the first <SAMP>`-'</SAMP>. This -allows <CODE>sun</CODE> to match both <CODE>sun</CODE> and <CODE>sun-cmd</CODE>, -for instance. -<P> - -<DT><CODE>application</CODE> -<DD>The <VAR>application</VAR> construct is used to include -application-specific settings. Each program using the Readline -library sets the <VAR>application name</VAR>, and you can test for -a particular value. -This could be used to bind key sequences to functions useful for -a specific program. For instance, the following command adds a -key sequence that quotes the current or previous word in Bash: -<TABLE><tr><td> </td><td class=example><pre>$if Bash -# Quote the current or previous word -"\C-xq": "\eb\"\ef\"" -$endif -</pre></td></tr></table></DL> -<P> - -<DT><CODE>$endif</CODE> -<DD>This command, as seen in the previous example, terminates an -<CODE>$if</CODE> command. -<P> - -<DT><CODE>$else</CODE> -<DD>Commands in this branch of the <CODE>$if</CODE> directive are executed if -the test fails. -<P> - -<DT><CODE>$include</CODE> -<DD>This directive takes a single filename as an argument and reads commands -and bindings from that file. -For example, the following directive reads from <TT>`/etc/inputrc'</TT>: -<TABLE><tr><td> </td><td class=example><pre>$include /etc/inputrc -</pre></td></tr></table></DL> -<P> - -<A NAME="Sample Init File"></A> -<HR SIZE="6"> -<A NAME="SEC104"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC103"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC101"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.3.3 Sample Init File </H3> -<!--docid::SEC104::--> -<P> - -Here is an example of an <VAR>inputrc</VAR> file. This illustrates key -binding, variable assignment, and conditional syntax. -</P><P> - -<TABLE><tr><td> </td><td class=example><pre># This file controls the behaviour of line input editing for -# programs that use the GNU Readline library. Existing -# programs include FTP, Bash, and GDB. -# -# You can re-read the inputrc file with C-x C-r. -# Lines beginning with '#' are comments. -# -# First, include any systemwide bindings and variable -# assignments from /etc/Inputrc -$include /etc/Inputrc - -# -# Set various bindings for emacs mode. - -set editing-mode emacs - -$if mode=emacs - -Meta-Control-h: backward-kill-word Text after the function name is ignored - -# -# Arrow keys in keypad mode -# -#"\M-OD": backward-char -#"\M-OC": forward-char -#"\M-OA": previous-history -#"\M-OB": next-history -# -# Arrow keys in ANSI mode -# -"\M-[D": backward-char -"\M-[C": forward-char -"\M-[A": previous-history -"\M-[B": next-history -# -# Arrow keys in 8 bit keypad mode -# -#"\M-\C-OD": backward-char -#"\M-\C-OC": forward-char -#"\M-\C-OA": previous-history -#"\M-\C-OB": next-history -# -# Arrow keys in 8 bit ANSI mode -# -#"\M-\C-[D": backward-char -#"\M-\C-[C": forward-char -#"\M-\C-[A": previous-history -#"\M-\C-[B": next-history - -C-q: quoted-insert - -$endif - -# An old-style binding. This happens to be the default. -TAB: complete - -# Macros that are convenient for shell interaction -$if Bash -# edit the path -"\C-xp": "PATH=${PATH}\e\C-e\C-a\ef\C-f" -# prepare to type a quoted word -- -# insert open and close double quotes -# and move to just after the open quote -"\C-x\"": "\"\"\C-b" -# insert a backslash (testing backslash escapes -# in sequences and macros) -"\C-x\\": "\\" -# Quote the current or previous word -"\C-xq": "\eb\"\ef\"" -# Add a binding to refresh the line, which is unbound -"\C-xr": redraw-current-line -# Edit variable on current line. -"\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y=" -$endif - -# use a visible bell if one is available -set bell-style visible - -# don't strip characters to 7 bits when reading -set input-meta on - -# allow iso-latin1 characters to be inserted rather -# than converted to prefix-meta sequences -set convert-meta off - -# display characters with the eighth bit set directly -# rather than as meta-prefixed characters -set output-meta on - -# if there are more than 150 possible completions for -# a word, ask the user if he wants to see all of them -set completion-query-items 150 - -# For FTP -$if Ftp -"\C-xg": "get \M-?" -"\C-xt": "put \M-?" -"\M-.": yank-last-arg -$endif -</pre></td></tr></table></P><P> - -<A NAME="Bindable Readline Commands"></A> -<HR SIZE="6"> -<A NAME="SEC105"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC104"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC106"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 8.4 Bindable Readline Commands </H2> -<!--docid::SEC105::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Moving about the line.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Getting at previous lines.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Commands for changing text.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Commands for killing and yanking.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC110">8.4.5 Specifying Numeric Arguments</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Specifying numeric arguments, repeat counts.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Getting Readline to do the typing for you.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC112">8.4.7 Keyboard Macros</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Saving and re-executing typed characters</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Other miscellaneous commands.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -This section describes Readline commands that may be bound to key -sequences. -You can list your key bindings by executing -<CODE>bind -P</CODE> or, for a more terse format, suitable for an -<VAR>inputrc</VAR> file, <CODE>bind -p</CODE>. (See section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>.) -Command names without an accompanying key sequence are unbound by default. -</P><P> - -In the following descriptions, <EM>point</EM> refers to the current cursor -position, and <EM>mark</EM> refers to a cursor position saved by the -<CODE>set-mark</CODE> command. -The text between the point and mark is referred to as the <EM>region</EM>. -</P><P> - -<A NAME="Commands For Moving"></A> -<HR SIZE="6"> -<A NAME="SEC106"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC107"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.1 Commands For Moving </H3> -<!--docid::SEC106::--> -<DL COMPACT> -<A NAME="IDX318"></A> -<DT><CODE>beginning-of-line (C-a)</CODE> -<DD><A NAME="IDX319"></A> -Move to the start of the current line. -<P> - -<A NAME="IDX320"></A> -<DT><CODE>end-of-line (C-e)</CODE> -<DD><A NAME="IDX321"></A> -Move to the end of the line. -<P> - -<A NAME="IDX322"></A> -<DT><CODE>forward-char (C-f)</CODE> -<DD><A NAME="IDX323"></A> -Move forward a character. -<P> - -<A NAME="IDX324"></A> -<DT><CODE>backward-char (C-b)</CODE> -<DD><A NAME="IDX325"></A> -Move back a character. -<P> - -<A NAME="IDX326"></A> -<DT><CODE>forward-word (M-f)</CODE> -<DD><A NAME="IDX327"></A> -Move forward to the end of the next word. Words are composed of -letters and digits. -<P> - -<A NAME="IDX328"></A> -<DT><CODE>backward-word (M-b)</CODE> -<DD><A NAME="IDX329"></A> -Move back to the start of the current or previous word. Words are -composed of letters and digits. -<P> - -<A NAME="IDX330"></A> -<DT><CODE>clear-screen (C-l)</CODE> -<DD><A NAME="IDX331"></A> -Clear the screen and redraw the current line, -leaving the current line at the top of the screen. -<P> - -<A NAME="IDX332"></A> -<DT><CODE>redraw-current-line ()</CODE> -<DD><A NAME="IDX333"></A> -Refresh the current line. By default, this is unbound. -<P> - -</DL> -<P> - -<A NAME="Commands For History"></A> -<HR SIZE="6"> -<A NAME="SEC107"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC106"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC108"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC108"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.2 Commands For Manipulating The History </H3> -<!--docid::SEC107::--> -<P> - -<DL COMPACT> -<A NAME="IDX334"></A> -<DT><CODE>accept-line (Newline or Return)</CODE> -<DD><A NAME="IDX335"></A> -Accept the line regardless of where the cursor is. -If this line is -non-empty, add it to the history list according to the setting of -the <CODE>HISTCONTROL</CODE> and <CODE>HISTIGNORE</CODE> variables. -If this line is a modified history line, then restore the history line -to its original state. -<P> - -<A NAME="IDX336"></A> -<DT><CODE>previous-history (C-p)</CODE> -<DD><A NAME="IDX337"></A> -Move `back' through the history list, fetching the previous command. -<P> - -<A NAME="IDX338"></A> -<DT><CODE>next-history (C-n)</CODE> -<DD><A NAME="IDX339"></A> -Move `forward' through the history list, fetching the next command. -<P> - -<A NAME="IDX340"></A> -<DT><CODE>beginning-of-history (M-<)</CODE> -<DD><A NAME="IDX341"></A> -Move to the first line in the history. -<P> - -<A NAME="IDX342"></A> -<DT><CODE>end-of-history (M->)</CODE> -<DD><A NAME="IDX343"></A> -Move to the end of the input history, i.e., the line currently -being entered. -<P> - -<A NAME="IDX344"></A> -<DT><CODE>reverse-search-history (C-r)</CODE> -<DD><A NAME="IDX345"></A> -Search backward starting at the current line and moving `up' through -the history as necessary. This is an incremental search. -<P> - -<A NAME="IDX346"></A> -<DT><CODE>forward-search-history (C-s)</CODE> -<DD><A NAME="IDX347"></A> -Search forward starting at the current line and moving `down' through -the the history as necessary. This is an incremental search. -<P> - -<A NAME="IDX348"></A> -<DT><CODE>non-incremental-reverse-search-history (M-p)</CODE> -<DD><A NAME="IDX349"></A> -Search backward starting at the current line and moving `up' -through the history as necessary using a non-incremental search -for a string supplied by the user. -<P> - -<A NAME="IDX350"></A> -<DT><CODE>non-incremental-forward-search-history (M-n)</CODE> -<DD><A NAME="IDX351"></A> -Search forward starting at the current line and moving `down' -through the the history as necessary using a non-incremental search -for a string supplied by the user. -<P> - -<A NAME="IDX352"></A> -<DT><CODE>history-search-forward ()</CODE> -<DD><A NAME="IDX353"></A> -Search forward through the history for the string of characters -between the start of the current line and the point. -This is a non-incremental search. -By default, this command is unbound. -<P> - -<A NAME="IDX354"></A> -<DT><CODE>history-search-backward ()</CODE> -<DD><A NAME="IDX355"></A> -Search backward through the history for the string of characters -between the start of the current line and the point. This -is a non-incremental search. By default, this command is unbound. -<P> - -<A NAME="IDX356"></A> -<DT><CODE>yank-nth-arg (M-C-y)</CODE> -<DD><A NAME="IDX357"></A> -Insert the first argument to the previous command (usually -the second word on the previous line) at point. -With an argument <VAR>n</VAR>, -insert the <VAR>n</VAR>th word from the previous command (the words -in the previous command begin with word 0). A negative argument -inserts the <VAR>n</VAR>th word from the end of the previous command. -Once the argument <VAR>n</VAR> is computed, the argument is extracted -as if the <SAMP>`!<VAR>n</VAR>'</SAMP> history expansion had been specified. -<P> - -<A NAME="IDX358"></A> -<DT><CODE>yank-last-arg (M-. or M-_)</CODE> -<DD><A NAME="IDX359"></A> -Insert last argument to the previous command (the last word of the -previous history entry). With an -argument, behave exactly like <CODE>yank-nth-arg</CODE>. -Successive calls to <CODE>yank-last-arg</CODE> move back through the history -list, inserting the last argument of each line in turn. -The history expansion facilities are used to extract the last argument, -as if the <SAMP>`!$'</SAMP> history expansion had been specified. -<P> - -</DL> -<P> - -<A NAME="Commands For Text"></A> -<HR SIZE="6"> -<A NAME="SEC108"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC107"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC109"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC109"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.3 Commands For Changing Text </H3> -<!--docid::SEC108::--> -<P> - -<DL COMPACT> -<A NAME="IDX360"></A> -<DT><CODE>delete-char (C-d)</CODE> -<DD><A NAME="IDX361"></A> -Delete the character at point. If point is at the -beginning of the line, there are no characters in the line, and -the last character typed was not bound to <CODE>delete-char</CODE>, then -return EOF. -<P> - -<A NAME="IDX362"></A> -<DT><CODE>backward-delete-char (Rubout)</CODE> -<DD><A NAME="IDX363"></A> -Delete the character behind the cursor. A numeric argument means -to kill the characters instead of deleting them. -<P> - -<A NAME="IDX364"></A> -<DT><CODE>forward-backward-delete-char ()</CODE> -<DD><A NAME="IDX365"></A> -Delete the character under the cursor, unless the cursor is at the -end of the line, in which case the character behind the cursor is -deleted. By default, this is not bound to a key. -<P> - -<A NAME="IDX366"></A> -<DT><CODE>quoted-insert (C-q or C-v)</CODE> -<DD><A NAME="IDX367"></A> -Add the next character typed to the line verbatim. This is -how to insert key sequences like <KBD>C-q</KBD>, for example. -<P> - -<A NAME="IDX368"></A> -<DT><CODE>self-insert (a, b, A, 1, !, <small>...</small>)</CODE> -<DD><A NAME="IDX369"></A> -Insert yourself. -<P> - -<A NAME="IDX370"></A> -<DT><CODE>transpose-chars (C-t)</CODE> -<DD><A NAME="IDX371"></A> -Drag the character before the cursor forward over -the character at the cursor, moving the -cursor forward as well. If the insertion point -is at the end of the line, then this -transposes the last two characters of the line. -Negative arguments have no effect. -<P> - -<A NAME="IDX372"></A> -<DT><CODE>transpose-words (M-t)</CODE> -<DD><A NAME="IDX373"></A> -Drag the word before point past the word after point, -moving point past that word as well. -If the insertion point is at the end of the line, this transposes -the last two words on the line. -<P> - -<A NAME="IDX374"></A> -<DT><CODE>upcase-word (M-u)</CODE> -<DD><A NAME="IDX375"></A> -Uppercase the current (or following) word. With a negative argument, -uppercase the previous word, but do not move the cursor. -<P> - -<A NAME="IDX376"></A> -<DT><CODE>downcase-word (M-l)</CODE> -<DD><A NAME="IDX377"></A> -Lowercase the current (or following) word. With a negative argument, -lowercase the previous word, but do not move the cursor. -<P> - -<A NAME="IDX378"></A> -<DT><CODE>capitalize-word (M-c)</CODE> -<DD><A NAME="IDX379"></A> -Capitalize the current (or following) word. With a negative argument, -capitalize the previous word, but do not move the cursor. -<P> - -<A NAME="IDX380"></A> -<DT><CODE>overwrite-mode ()</CODE> -<DD><A NAME="IDX381"></A> -Toggle overwrite mode. With an explicit positive numeric argument, -switches to overwrite mode. With an explicit non-positive numeric -argument, switches to insert mode. This command affects only -<CODE>emacs</CODE> mode; <CODE>vi</CODE> mode does overwrite differently. -Each call to <CODE>readline()</CODE> starts in insert mode. -<P> - -In overwrite mode, characters bound to <CODE>self-insert</CODE> replace -the text at point rather than pushing the text to the right. -Characters bound to <CODE>backward-delete-char</CODE> replace the character -before point with a space. -</P><P> - -By default, this command is unbound. -</P><P> - -</DL> -<P> - -<A NAME="Commands For Killing"></A> -<HR SIZE="6"> -<A NAME="SEC109"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC108"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC110"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC110"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.4 Killing And Yanking </H3> -<!--docid::SEC109::--> -<P> - -<DL COMPACT> - -<A NAME="IDX382"></A> -<DT><CODE>kill-line (C-k)</CODE> -<DD><A NAME="IDX383"></A> -Kill the text from point to the end of the line. -<P> - -<A NAME="IDX384"></A> -<DT><CODE>backward-kill-line (C-x Rubout)</CODE> -<DD><A NAME="IDX385"></A> -Kill backward to the beginning of the line. -<P> - -<A NAME="IDX386"></A> -<DT><CODE>unix-line-discard (C-u)</CODE> -<DD><A NAME="IDX387"></A> -Kill backward from the cursor to the beginning of the current line. -<P> - -<A NAME="IDX388"></A> -<DT><CODE>kill-whole-line ()</CODE> -<DD><A NAME="IDX389"></A> -Kill all characters on the current line, no matter where point is. -By default, this is unbound. -<P> - -<A NAME="IDX390"></A> -<DT><CODE>kill-word (M-d)</CODE> -<DD><A NAME="IDX391"></A> -Kill from point to the end of the current word, or if between -words, to the end of the next word. -Word boundaries are the same as <CODE>forward-word</CODE>. -<P> - -<A NAME="IDX392"></A> -<DT><CODE>backward-kill-word (M-<KBD>DEL</KBD>)</CODE> -<DD><A NAME="IDX393"></A> -Kill the word behind point. -Word boundaries are the same as <CODE>backward-word</CODE>. -<P> - -<A NAME="IDX394"></A> -<DT><CODE>unix-word-rubout (C-w)</CODE> -<DD><A NAME="IDX395"></A> -Kill the word behind point, using white space as a word boundary. -The killed text is saved on the kill-ring. -<P> - -<A NAME="IDX396"></A> -<DT><CODE>unix-filename-rubout ()</CODE> -<DD><A NAME="IDX397"></A> -Kill the word behind point, using white space and the slash character -as the word boundaries. -The killed text is saved on the kill-ring. -<P> - -<A NAME="IDX398"></A> -<DT><CODE>delete-horizontal-space ()</CODE> -<DD><A NAME="IDX399"></A> -Delete all spaces and tabs around point. By default, this is unbound. -<P> - -<A NAME="IDX400"></A> -<DT><CODE>kill-region ()</CODE> -<DD><A NAME="IDX401"></A> -Kill the text in the current region. -By default, this command is unbound. -<P> - -<A NAME="IDX402"></A> -<DT><CODE>copy-region-as-kill ()</CODE> -<DD><A NAME="IDX403"></A> -Copy the text in the region to the kill buffer, so it can be yanked -right away. By default, this command is unbound. -<P> - -<A NAME="IDX404"></A> -<DT><CODE>copy-backward-word ()</CODE> -<DD><A NAME="IDX405"></A> -Copy the word before point to the kill buffer. -The word boundaries are the same as <CODE>backward-word</CODE>. -By default, this command is unbound. -<P> - -<A NAME="IDX406"></A> -<DT><CODE>copy-forward-word ()</CODE> -<DD><A NAME="IDX407"></A> -Copy the word following point to the kill buffer. -The word boundaries are the same as <CODE>forward-word</CODE>. -By default, this command is unbound. -<P> - -<A NAME="IDX408"></A> -<DT><CODE>yank (C-y)</CODE> -<DD><A NAME="IDX409"></A> -Yank the top of the kill ring into the buffer at point. -<P> - -<A NAME="IDX410"></A> -<DT><CODE>yank-pop (M-y)</CODE> -<DD><A NAME="IDX411"></A> -Rotate the kill-ring, and yank the new top. You can only do this if -the prior command is <CODE>yank</CODE> or <CODE>yank-pop</CODE>. -</DL> -<P> - -<A NAME="Numeric Arguments"></A> -<HR SIZE="6"> -<A NAME="SEC110"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC109"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC111"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC111"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.5 Specifying Numeric Arguments </H3> -<!--docid::SEC110::--> -<DL COMPACT> - -<A NAME="IDX412"></A> -<DT><CODE>digit-argument (<KBD>M-0</KBD>, <KBD>M-1</KBD>, <small>...</small> <KBD>M--</KBD>)</CODE> -<DD><A NAME="IDX413"></A> -Add this digit to the argument already accumulating, or start a new -argument. <KBD>M--</KBD> starts a negative argument. -<P> - -<A NAME="IDX414"></A> -<DT><CODE>universal-argument ()</CODE> -<DD><A NAME="IDX415"></A> -This is another way to specify an argument. -If this command is followed by one or more digits, optionally with a -leading minus sign, those digits define the argument. -If the command is followed by digits, executing <CODE>universal-argument</CODE> -again ends the numeric argument, but is otherwise ignored. -As a special case, if this command is immediately followed by a -character that is neither a digit or minus sign, the argument count -for the next command is multiplied by four. -The argument count is initially one, so executing this function the -first time makes the argument count four, a second time makes the -argument count sixteen, and so on. -By default, this is not bound to a key. -</DL> -<P> - -<A NAME="Commands For Completion"></A> -<HR SIZE="6"> -<A NAME="SEC111"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC110"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC112"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC112"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.6 Letting Readline Type For You </H3> -<!--docid::SEC111::--> -<P> - -<DL COMPACT> -<A NAME="IDX416"></A> -<DT><CODE>complete (<KBD>TAB</KBD>)</CODE> -<DD><A NAME="IDX417"></A> -Attempt to perform completion on the text before point. -The actual completion performed is application-specific. -Bash attempts completion treating the text as a variable (if the -text begins with <SAMP>`$'</SAMP>), username (if the text begins with -<SAMP>`~'</SAMP>), hostname (if the text begins with <SAMP>`@'</SAMP>), or -command (including aliases and functions) in turn. If none -of these produces a match, filename completion is attempted. -<P> - -<A NAME="IDX418"></A> -<DT><CODE>possible-completions (M-?)</CODE> -<DD><A NAME="IDX419"></A> -List the possible completions of the text before point. -<P> - -<A NAME="IDX420"></A> -<DT><CODE>insert-completions (M-*)</CODE> -<DD><A NAME="IDX421"></A> -Insert all completions of the text before point that would have -been generated by <CODE>possible-completions</CODE>. -<P> - -<A NAME="IDX422"></A> -<DT><CODE>menu-complete ()</CODE> -<DD><A NAME="IDX423"></A> -Similar to <CODE>complete</CODE>, but replaces the word to be completed -with a single match from the list of possible completions. -Repeated execution of <CODE>menu-complete</CODE> steps through the list -of possible completions, inserting each match in turn. -At the end of the list of completions, the bell is rung -(subject to the setting of <CODE>bell-style</CODE>) -and the original text is restored. -An argument of <VAR>n</VAR> moves <VAR>n</VAR> positions forward in the list -of matches; a negative argument may be used to move backward -through the list. -This command is intended to be bound to <KBD>TAB</KBD>, but is unbound -by default. -<P> - -<A NAME="IDX424"></A> -<DT><CODE>delete-char-or-list ()</CODE> -<DD><A NAME="IDX425"></A> -Deletes the character under the cursor if not at the beginning or -end of the line (like <CODE>delete-char</CODE>). -If at the end of the line, behaves identically to -<CODE>possible-completions</CODE>. -This command is unbound by default. -<P> - -<A NAME="IDX426"></A> -<DT><CODE>complete-filename (M-/)</CODE> -<DD><A NAME="IDX427"></A> -Attempt filename completion on the text before point. -<P> - -<A NAME="IDX428"></A> -<DT><CODE>possible-filename-completions (C-x /)</CODE> -<DD><A NAME="IDX429"></A> -List the possible completions of the text before point, -treating it as a filename. -<P> - -<A NAME="IDX430"></A> -<DT><CODE>complete-username (M-~)</CODE> -<DD><A NAME="IDX431"></A> -Attempt completion on the text before point, treating -it as a username. -<P> - -<A NAME="IDX432"></A> -<DT><CODE>possible-username-completions (C-x ~)</CODE> -<DD><A NAME="IDX433"></A> -List the possible completions of the text before point, -treating it as a username. -<P> - -<A NAME="IDX434"></A> -<DT><CODE>complete-variable (M-$)</CODE> -<DD><A NAME="IDX435"></A> -Attempt completion on the text before point, treating -it as a shell variable. -<P> - -<A NAME="IDX436"></A> -<DT><CODE>possible-variable-completions (C-x $)</CODE> -<DD><A NAME="IDX437"></A> -List the possible completions of the text before point, -treating it as a shell variable. -<P> - -<A NAME="IDX438"></A> -<DT><CODE>complete-hostname (M-@)</CODE> -<DD><A NAME="IDX439"></A> -Attempt completion on the text before point, treating -it as a hostname. -<P> - -<A NAME="IDX440"></A> -<DT><CODE>possible-hostname-completions (C-x @)</CODE> -<DD><A NAME="IDX441"></A> -List the possible completions of the text before point, -treating it as a hostname. -<P> - -<A NAME="IDX442"></A> -<DT><CODE>complete-command (M-!)</CODE> -<DD><A NAME="IDX443"></A> -Attempt completion on the text before point, treating -it as a command name. Command completion attempts to -match the text against aliases, reserved words, shell -functions, shell builtins, and finally executable filenames, -in that order. -<P> - -<A NAME="IDX444"></A> -<DT><CODE>possible-command-completions (C-x !)</CODE> -<DD><A NAME="IDX445"></A> -List the possible completions of the text before point, -treating it as a command name. -<P> - -<A NAME="IDX446"></A> -<DT><CODE>dynamic-complete-history (M-<KBD>TAB</KBD>)</CODE> -<DD><A NAME="IDX447"></A> -Attempt completion on the text before point, comparing -the text against lines from the history list for possible -completion matches. -<P> - -<A NAME="IDX448"></A> -<DT><CODE>complete-into-braces (M-{)</CODE> -<DD><A NAME="IDX449"></A> -Perform filename completion and insert the list of possible completions -enclosed within braces so the list is available to the shell -(see section <A HREF="b.html#SEC28">3.5.1 Brace Expansion</A>). -<P> - -</DL> -<P> - -<A NAME="Keyboard Macros"></A> -<HR SIZE="6"> -<A NAME="SEC112"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC111"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC113"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC113"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.7 Keyboard Macros </H3> -<!--docid::SEC112::--> -<DL COMPACT> - -<A NAME="IDX450"></A> -<DT><CODE>start-kbd-macro (C-x ()</CODE> -<DD><A NAME="IDX451"></A> -Begin saving the characters typed into the current keyboard macro. -<P> - -<A NAME="IDX452"></A> -<DT><CODE>end-kbd-macro (C-x ))</CODE> -<DD><A NAME="IDX453"></A> -Stop saving the characters typed into the current keyboard macro -and save the definition. -<P> - -<A NAME="IDX454"></A> -<DT><CODE>call-last-kbd-macro (C-x e)</CODE> -<DD><A NAME="IDX455"></A> -Re-execute the last keyboard macro defined, by making the characters -in the macro appear as if typed at the keyboard. -<P> - -</DL> -<P> - -<A NAME="Miscellaneous Commands"></A> -<HR SIZE="6"> -<A NAME="SEC113"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC112"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC105"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 8.4.8 Some Miscellaneous Commands </H3> -<!--docid::SEC113::--> -<DL COMPACT> - -<A NAME="IDX456"></A> -<DT><CODE>re-read-init-file (C-x C-r)</CODE> -<DD><A NAME="IDX457"></A> -Read in the contents of the <VAR>inputrc</VAR> file, and incorporate -any bindings or variable assignments found there. -<P> - -<A NAME="IDX458"></A> -<DT><CODE>abort (C-g)</CODE> -<DD><A NAME="IDX459"></A> -Abort the current editing command and -ring the terminal's bell (subject to the setting of -<CODE>bell-style</CODE>). -<P> - -<A NAME="IDX460"></A> -<DT><CODE>do-uppercase-version (M-a, M-b, M-<VAR>x</VAR>, <small>...</small>)</CODE> -<DD><A NAME="IDX461"></A> -If the metafied character <VAR>x</VAR> is lowercase, run the command -that is bound to the corresponding uppercase character. -<P> - -<A NAME="IDX462"></A> -<DT><CODE>prefix-meta (<KBD>ESC</KBD>)</CODE> -<DD><A NAME="IDX463"></A> -Metafy the next character typed. This is for keyboards -without a meta key. Typing <SAMP>`<KBD>ESC</KBD> f'</SAMP> is equivalent to typing -<KBD>M-f</KBD>. -<P> - -<A NAME="IDX464"></A> -<DT><CODE>undo (C-_ or C-x C-u)</CODE> -<DD><A NAME="IDX465"></A> -Incremental undo, separately remembered for each line. -<P> - -<A NAME="IDX466"></A> -<DT><CODE>revert-line (M-r)</CODE> -<DD><A NAME="IDX467"></A> -Undo all changes made to this line. This is like executing the <CODE>undo</CODE> -command enough times to get back to the beginning. -<P> - -<A NAME="IDX468"></A> -<DT><CODE>tilde-expand (M-&)</CODE> -<DD><A NAME="IDX469"></A> -Perform tilde expansion on the current word. -<P> - -<A NAME="IDX470"></A> -<DT><CODE>set-mark (C-@)</CODE> -<DD><A NAME="IDX471"></A> -Set the mark to the point. If a -numeric argument is supplied, the mark is set to that position. -<P> - -<A NAME="IDX472"></A> -<DT><CODE>exchange-point-and-mark (C-x C-x)</CODE> -<DD><A NAME="IDX473"></A> -Swap the point with the mark. The current cursor position is set to -the saved position, and the old cursor position is saved as the mark. -<P> - -<A NAME="IDX474"></A> -<DT><CODE>character-search (C-])</CODE> -<DD><A NAME="IDX475"></A> -A character is read and point is moved to the next occurrence of that -character. A negative count searches for previous occurrences. -<P> - -<A NAME="IDX476"></A> -<DT><CODE>character-search-backward (M-C-])</CODE> -<DD><A NAME="IDX477"></A> -A character is read and point is moved to the previous occurrence -of that character. A negative count searches for subsequent -occurrences. -<P> - -<A NAME="IDX478"></A> -<DT><CODE>insert-comment (M-#)</CODE> -<DD><A NAME="IDX479"></A> -Without a numeric argument, the value of the <CODE>comment-begin</CODE> -variable is inserted at the beginning of the current line. -If a numeric argument is supplied, this command acts as a toggle: if -the characters at the beginning of the line do not match the value -of <CODE>comment-begin</CODE>, the value is inserted, otherwise -the characters in <CODE>comment-begin</CODE> are deleted from the beginning of -the line. -In either case, the line is accepted as if a newline had been typed. -The default value of <CODE>comment-begin</CODE> causes this command -to make the current line a shell comment. -If a numeric argument causes the comment character to be removed, the line -will be executed by the shell. -<P> - -<A NAME="IDX480"></A> -<DT><CODE>dump-functions ()</CODE> -<DD><A NAME="IDX481"></A> -Print all of the functions and their key bindings to the -Readline output stream. If a numeric argument is supplied, -the output is formatted in such a way that it can be made part -of an <VAR>inputrc</VAR> file. This command is unbound by default. -<P> - -<A NAME="IDX482"></A> -<DT><CODE>dump-variables ()</CODE> -<DD><A NAME="IDX483"></A> -Print all of the settable variables and their values to the -Readline output stream. If a numeric argument is supplied, -the output is formatted in such a way that it can be made part -of an <VAR>inputrc</VAR> file. This command is unbound by default. -<P> - -<A NAME="IDX484"></A> -<DT><CODE>dump-macros ()</CODE> -<DD><A NAME="IDX485"></A> -Print all of the Readline key sequences bound to macros and the -strings they output. If a numeric argument is supplied, -the output is formatted in such a way that it can be made part -of an <VAR>inputrc</VAR> file. This command is unbound by default. -<P> - -<A NAME="IDX486"></A> -<DT><CODE>glob-complete-word (M-g)</CODE> -<DD><A NAME="IDX487"></A> -The word before point is treated as a pattern for pathname expansion, -with an asterisk implicitly appended. This pattern is used to -generate a list of matching file names for possible completions. -<P> - -<A NAME="IDX488"></A> -<DT><CODE>glob-expand-word (C-x *)</CODE> -<DD><A NAME="IDX489"></A> -The word before point is treated as a pattern for pathname expansion, -and the list of matching file names is inserted, replacing the word. -If a numeric argument is supplied, a <SAMP>`*'</SAMP> is appended before -pathname expansion. -<P> - -<A NAME="IDX490"></A> -<DT><CODE>glob-list-expansions (C-x g)</CODE> -<DD><A NAME="IDX491"></A> -The list of expansions that would have been generated by -<CODE>glob-expand-word</CODE> is displayed, and the line is redrawn. -If a numeric argument is supplied, a <SAMP>`*'</SAMP> is appended before -pathname expansion. -<P> - -<A NAME="IDX492"></A> -<DT><CODE>display-shell-version (C-x C-v)</CODE> -<DD><A NAME="IDX493"></A> -Display version information about the current instance of Bash. -<P> - -<A NAME="IDX494"></A> -<DT><CODE>shell-expand-line (M-C-e)</CODE> -<DD><A NAME="IDX495"></A> -Expand the line as the shell does. -This performs alias and history expansion as well as all of the shell -word expansions (see section <A HREF="b.html#SEC27">3.5 Shell Expansions</A>). -<P> - -<A NAME="IDX496"></A> -<DT><CODE>history-expand-line (M-^)</CODE> -<DD><A NAME="IDX497"></A> -Perform history expansion on the current line. -<P> - -<A NAME="IDX498"></A> -<DT><CODE>magic-space ()</CODE> -<DD><A NAME="IDX499"></A> -Perform history expansion on the current line and insert a space -(see section <A HREF="b.html#SEC120">9.3 History Expansion</A>). -<P> - -<A NAME="IDX500"></A> -<DT><CODE>alias-expand-line ()</CODE> -<DD><A NAME="IDX501"></A> -Perform alias expansion on the current line (see section <A HREF="b.html#SEC82">6.6 Aliases</A>). -<P> - -<A NAME="IDX502"></A> -<DT><CODE>history-and-alias-expand-line ()</CODE> -<DD><A NAME="IDX503"></A> -Perform history and alias expansion on the current line. -<P> - -<A NAME="IDX504"></A> -<DT><CODE>insert-last-argument (M-. or M-_)</CODE> -<DD><A NAME="IDX505"></A> -A synonym for <CODE>yank-last-arg</CODE>. -<P> - -<A NAME="IDX506"></A> -<DT><CODE>operate-and-get-next (C-o)</CODE> -<DD><A NAME="IDX507"></A> -Accept the current line for execution and fetch the next line -relative to the current line from the history for editing. Any -argument is ignored. -<P> - -<A NAME="IDX508"></A> -<DT><CODE>edit-and-execute-command (C-xC-e)</CODE> -<DD><A NAME="IDX509"></A> -Invoke an editor on the current command line, and execute the result as shell -commands. -Bash attempts to invoke -<CODE>$VISUAL</CODE>, <CODE>$EDITOR</CODE>, and <CODE>emacs</CODE> -as the editor, in that order. -<P> - -</DL> -<P> - -<A NAME="Readline vi Mode"></A> -<HR SIZE="6"> -<A NAME="SEC114"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC113"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC115"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC115"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 8.5 Readline vi Mode </H2> -<!--docid::SEC114::--> -<P> - -While the Readline library does not have a full set of <CODE>vi</CODE> -editing functions, it does contain enough to allow simple editing -of the line. The Readline <CODE>vi</CODE> mode behaves as specified in -the POSIX 1003.2 standard. -</P><P> - -In order to switch interactively between <CODE>emacs</CODE> and <CODE>vi</CODE> -editing modes, use the <SAMP>`set -o emacs'</SAMP> and <SAMP>`set -o vi'</SAMP> -commands (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -The Readline default is <CODE>emacs</CODE> mode. -</P><P> - -When you enter a line in <CODE>vi</CODE> mode, you are already placed in -`insertion' mode, as if you had typed an <SAMP>`i'</SAMP>. Pressing <KBD>ESC</KBD> -switches you into `command' mode, where you can edit the text of the -line with the standard <CODE>vi</CODE> movement keys, move to previous -history lines with <SAMP>`k'</SAMP> and subsequent lines with <SAMP>`j'</SAMP>, and -so forth. -</P><P> - -<A NAME="Programmable Completion"></A> -<HR SIZE="6"> -<A NAME="SEC115"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC114"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC116"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC116"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 8.6 Programmable Completion </H2> -<!--docid::SEC115::--> -<P> - -When word completion is attempted for an argument to a command for -which a completion specification (a <VAR>compspec</VAR>) has been defined -using the <CODE>complete</CODE> builtin (see section <A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A>), -the programmable completion facilities are invoked. -</P><P> - -First, the command name is identified. -If a compspec has been defined for that command, the -compspec is used to generate the list of possible completions for the word. -If the command word is a full pathname, a compspec for the full -pathname is searched for first. -If no compspec is found for the full pathname, an attempt is made to -find a compspec for the portion following the final slash. -</P><P> - -Once a compspec has been found, it is used to generate the list of -matching words. -If a compspec is not found, the default Bash completion -described above (see section <A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A>) is performed. -</P><P> - -First, the actions specified by the compspec are used. -Only matches which are prefixed by the word being completed are -returned. -When the <SAMP>`-f'</SAMP> or <SAMP>`-d'</SAMP> option is used for filename or -directory name completion, the shell variable <CODE>FIGNORE</CODE> is -used to filter the matches. -See section <A HREF="b.html#SEC65">5.2 Bash Variables</A>, for a description of <CODE>FIGNORE</CODE>. -</P><P> - -Any completions specified by a filename expansion pattern to the -<SAMP>`-G'</SAMP> option are generated next. -The words generated by the pattern need not match the word being completed. -The <CODE>GLOBIGNORE</CODE> shell variable is not used to filter the matches, -but the <CODE>FIGNORE</CODE> shell variable is used. -</P><P> - -Next, the string specified as the argument to the <SAMP>`-W'</SAMP> option -is considered. -The string is first split using the characters in the <CODE>IFS</CODE> -special variable as delimiters. -Shell quoting is honored. -Each word is then expanded using -brace expansion, tilde expansion, parameter and variable expansion, -command substitution, and arithmetic expansion, -as described above (see section <A HREF="b.html#SEC27">3.5 Shell Expansions</A>). -The results are split using the rules described above -(see section <A HREF="b.html#SEC34">3.5.7 Word Splitting</A>). -The results of the expansion are prefix-matched against the word being -completed, and the matching words become the possible completions. -</P><P> - -After these matches have been generated, any shell function or command -specified with the <SAMP>`-F'</SAMP> and <SAMP>`-C'</SAMP> options is invoked. -When the command or function is invoked, the <CODE>COMP_LINE</CODE>, -<CODE>COMP_POINT</CODE>, <CODE>COMP_KEY</CODE>, and <CODE>COMP_TYPE</CODE> variables are -assigned values as described above (see section <A HREF="b.html#SEC65">5.2 Bash Variables</A>). -If a shell function is being invoked, the <CODE>COMP_WORDS</CODE> and -<CODE>COMP_CWORD</CODE> variables are also set. -When the function or command is invoked, the first argument is the -name of the command whose arguments are being completed, the -second argument is the word being completed, and the third argument -is the word preceding the word being completed on the current command line. -No filtering of the generated completions against the word being completed -is performed; the function or command has complete freedom in generating -the matches. -</P><P> - -Any function specified with <SAMP>`-F'</SAMP> is invoked first. -The function may use any of the shell facilities, including the -<CODE>compgen</CODE> builtin described below -(see section <A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A>), to generate the matches. -It must put the possible completions in the <CODE>COMPREPLY</CODE> array -variable. -</P><P> - -Next, any command specified with the <SAMP>`-C'</SAMP> option is invoked -in an environment equivalent to command substitution. -It should print a list of completions, one per line, to -the standard output. -Backslash may be used to escape a newline, if necessary. -</P><P> - -After all of the possible completions are generated, any filter -specified with the <SAMP>`-X'</SAMP> option is applied to the list. -The filter is a pattern as used for pathname expansion; a <SAMP>`&'</SAMP> -in the pattern is replaced with the text of the word being completed. -A literal <SAMP>`&'</SAMP> may be escaped with a backslash; the backslash -is removed before attempting a match. -Any completion that matches the pattern will be removed from the list. -A leading <SAMP>`!'</SAMP> negates the pattern; in this case any completion -not matching the pattern will be removed. -</P><P> - -Finally, any prefix and suffix specified with the <SAMP>`-P'</SAMP> and <SAMP>`-S'</SAMP> -options are added to each member of the completion list, and the result is -returned to the Readline completion code as the list of possible -completions. -</P><P> - -If the previously-applied actions do not generate any matches, and the -<SAMP>`-o dirnames'</SAMP> option was supplied to <CODE>complete</CODE> when the -compspec was defined, directory name completion is attempted. -</P><P> - -If the <SAMP>`-o plusdirs'</SAMP> option was supplied to <CODE>complete</CODE> when -the compspec was defined, directory name completion is attempted and any -matches are added to the results of the other actions. -</P><P> - -By default, if a compspec is found, whatever it generates is returned to -the completion code as the full set of possible completions. -The default Bash completions are not attempted, and the Readline default -of filename completion is disabled. -If the <SAMP>`-o bashdefault'</SAMP> option was supplied to <CODE>complete</CODE> when -the compspec was defined, the default Bash completions are attempted -if the compspec generates no matches. -If the <SAMP>`-o default'</SAMP> option was supplied to <CODE>complete</CODE> when the -compspec was defined, Readline's default completion will be performed -if the compspec (and, if attempted, the default Bash completions) -generate no matches. -</P><P> - -When a compspec indicates that directory name completion is desired, -the programmable completion functions force Readline to append a slash -to completed names which are symbolic links to directories, subject to -the value of the <VAR>mark-directories</VAR> Readline variable, regardless -of the setting of the <VAR>mark-symlinked-directories</VAR> Readline variable. -</P><P> - -<A NAME="Programmable Completion Builtins"></A> -<HR SIZE="6"> -<A NAME="SEC116"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC115"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC93"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 8.7 Programmable Completion Builtins </H2> -<!--docid::SEC116::--> -<P> - -Two builtin commands are available to manipulate the programmable completion -facilities. -</P><P> - -<DL COMPACT> -<DT><CODE>compgen</CODE> -<DD><A NAME="IDX510"></A> -<TABLE><tr><td> </td><td class=example><pre><CODE>compgen [<VAR>option</VAR>] [<VAR>word</VAR>]</CODE> -</pre></td></tr></table><P> - -Generate possible completion matches for <VAR>word</VAR> according to -the <VAR>option</VAR>s, which may be any option accepted by the -<CODE>complete</CODE> -builtin with the exception of <SAMP>`-p'</SAMP> and <SAMP>`-r'</SAMP>, and write -the matches to the standard output. -When using the <SAMP>`-F'</SAMP> or <SAMP>`-C'</SAMP> options, the various shell variables -set by the programmable completion facilities, while available, will not -have useful values. -</P><P> - -The matches will be generated in the same way as if the programmable -completion code had generated them directly from a completion specification -with the same flags. -If <VAR>word</VAR> is specified, only those completions matching <VAR>word</VAR> -will be displayed. -</P><P> - -The return value is true unless an invalid option is supplied, or no -matches were generated. -</P><P> - -<DT><CODE>complete</CODE> -<DD><A NAME="IDX511"></A> -<TABLE><tr><td> </td><td class=example><pre><CODE>complete [-abcdefgjksuv] [-o <VAR>comp-option</VAR>] [-A <VAR>action</VAR>] [-G <VAR>globpat</VAR>] [-W <VAR>wordlist</VAR>] -[-F <VAR>function</VAR>] [-C <VAR>command</VAR>] [-X <VAR>filterpat</VAR>] -[-P <VAR>prefix</VAR>] [-S <VAR>suffix</VAR>] <VAR>name</VAR> [<VAR>name</VAR> <small>...</small>]</CODE> -<CODE>complete -pr [<VAR>name</VAR> <small>...</small>]</CODE> -</pre></td></tr></table><P> - -Specify how arguments to each <VAR>name</VAR> should be completed. -If the <SAMP>`-p'</SAMP> option is supplied, or if no options are supplied, existing -completion specifications are printed in a way that allows them to be -reused as input. -The <SAMP>`-r'</SAMP> option removes a completion specification for -each <VAR>name</VAR>, or, if no <VAR>name</VAR>s are supplied, all -completion specifications. -</P><P> - -The process of applying these completion specifications when word completion -is attempted is described above (see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -</P><P> - -Other options, if specified, have the following meanings. -The arguments to the <SAMP>`-G'</SAMP>, <SAMP>`-W'</SAMP>, and <SAMP>`-X'</SAMP> options -(and, if necessary, the <SAMP>`-P'</SAMP> and <SAMP>`-S'</SAMP> options) -should be quoted to protect them from expansion before the -<CODE>complete</CODE> builtin is invoked. -</P><P> - -<DL COMPACT> -<DT><CODE>-o <VAR>comp-option</VAR></CODE> -<DD>The <VAR>comp-option</VAR> controls several aspects of the compspec's behavior -beyond the simple generation of completions. -<VAR>comp-option</VAR> may be one of: -<P> - -<DL COMPACT> - -<DT><CODE>bashdefault</CODE> -<DD>Perform the rest of the default Bash completions if the compspec -generates no matches. -<P> - -<DT><CODE>default</CODE> -<DD>Use Readline's default filename completion if the compspec generates -no matches. -<P> - -<DT><CODE>dirnames</CODE> -<DD>Perform directory name completion if the compspec generates no matches. -<P> - -<DT><CODE>filenames</CODE> -<DD>Tell Readline that the compspec generates filenames, so it can perform any -filename-specific processing (like adding a slash to directory names or -suppressing trailing spaces). This option is intended to be used with -shell functions specified with <SAMP>`-F'</SAMP>. -<P> - -<DT><CODE>nospace</CODE> -<DD>Tell Readline not to append a space (the default) to words completed at -the end of the line. -<P> - -<DT><CODE>plusdirs</CODE> -<DD>After any matches defined by the compspec are generated, -directory name completion is attempted and any -matches are added to the results of the other actions. -<P> - -</DL> -<P> - -<DT><CODE>-A <VAR>action</VAR></CODE> -<DD>The <VAR>action</VAR> may be one of the following to generate a list of possible -completions: -<P> - -<DL COMPACT> -<DT><CODE>alias</CODE> -<DD>Alias names. May also be specified as <SAMP>`-a'</SAMP>. -<P> - -<DT><CODE>arrayvar</CODE> -<DD>Array variable names. -<P> - -<DT><CODE>binding</CODE> -<DD>Readline key binding names (see section <A HREF="b.html#SEC105">8.4 Bindable Readline Commands</A>). -<P> - -<DT><CODE>builtin</CODE> -<DD>Names of shell builtin commands. May also be specified as <SAMP>`-b'</SAMP>. -<P> - -<DT><CODE>command</CODE> -<DD>Command names. May also be specified as <SAMP>`-c'</SAMP>. -<P> - -<DT><CODE>directory</CODE> -<DD>Directory names. May also be specified as <SAMP>`-d'</SAMP>. -<P> - -<DT><CODE>disabled</CODE> -<DD>Names of disabled shell builtins. -<P> - -<DT><CODE>enabled</CODE> -<DD>Names of enabled shell builtins. -<P> - -<DT><CODE>export</CODE> -<DD>Names of exported shell variables. May also be specified as <SAMP>`-e'</SAMP>. -<P> - -<DT><CODE>file</CODE> -<DD>File names. May also be specified as <SAMP>`-f'</SAMP>. -<P> - -<DT><CODE>function</CODE> -<DD>Names of shell functions. -<P> - -<DT><CODE>group</CODE> -<DD>Group names. May also be specified as <SAMP>`-g'</SAMP>. -<P> - -<DT><CODE>helptopic</CODE> -<DD>Help topics as accepted by the <CODE>help</CODE> builtin (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<DT><CODE>hostname</CODE> -<DD>Hostnames, as taken from the file specified by the -<CODE>HOSTFILE</CODE> shell variable (see section <A HREF="b.html#SEC65">5.2 Bash Variables</A>). -<P> - -<DT><CODE>job</CODE> -<DD>Job names, if job control is active. May also be specified as <SAMP>`-j'</SAMP>. -<P> - -<DT><CODE>keyword</CODE> -<DD>Shell reserved words. May also be specified as <SAMP>`-k'</SAMP>. -<P> - -<DT><CODE>running</CODE> -<DD>Names of running jobs, if job control is active. -<P> - -<DT><CODE>service</CODE> -<DD>Service names. May also be specified as <SAMP>`-s'</SAMP>. -<P> - -<DT><CODE>setopt</CODE> -<DD>Valid arguments for the <SAMP>`-o'</SAMP> option to the <CODE>set</CODE> builtin -(see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -<P> - -<DT><CODE>shopt</CODE> -<DD>Shell option names as accepted by the <CODE>shopt</CODE> builtin -(see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<DT><CODE>signal</CODE> -<DD>Signal names. -<P> - -<DT><CODE>stopped</CODE> -<DD>Names of stopped jobs, if job control is active. -<P> - -<DT><CODE>user</CODE> -<DD>User names. May also be specified as <SAMP>`-u'</SAMP>. -<P> - -<DT><CODE>variable</CODE> -<DD>Names of all shell variables. May also be specified as <SAMP>`-v'</SAMP>. -</DL> -<P> - -<DT><CODE>-G <VAR>globpat</VAR></CODE> -<DD>The filename expansion pattern <VAR>globpat</VAR> is expanded to generate -the possible completions. -<P> - -<DT><CODE>-W <VAR>wordlist</VAR></CODE> -<DD>The <VAR>wordlist</VAR> is split using the characters in the -<CODE>IFS</CODE> special variable as delimiters, and each resultant word -is expanded. -The possible completions are the members of the resultant list which -match the word being completed. -<P> - -<DT><CODE>-C <VAR>command</VAR></CODE> -<DD><VAR>command</VAR> is executed in a subshell environment, and its output is -used as the possible completions. -<P> - -<DT><CODE>-F <VAR>function</VAR></CODE> -<DD>The shell function <VAR>function</VAR> is executed in the current shell -environment. -When it finishes, the possible completions are retrieved from the value -of the <CODE>COMPREPLY</CODE> array variable. -<P> - -<DT><CODE>-X <VAR>filterpat</VAR></CODE> -<DD><VAR>filterpat</VAR> is a pattern as used for filename expansion. -It is applied to the list of possible completions generated by the -preceding options and arguments, and each completion matching -<VAR>filterpat</VAR> is removed from the list. -A leading <SAMP>`!'</SAMP> in <VAR>filterpat</VAR> negates the pattern; in this -case, any completion not matching <VAR>filterpat</VAR> is removed. -<P> - -<DT><CODE>-P <VAR>prefix</VAR></CODE> -<DD><VAR>prefix</VAR> is added at the beginning of each possible completion -after all other options have been applied. -<P> - -<DT><CODE>-S <VAR>suffix</VAR></CODE> -<DD><VAR>suffix</VAR> is appended to each possible completion -after all other options have been applied. -</DL> -<P> - -The return value is true unless an invalid option is supplied, an option -other than <SAMP>`-p'</SAMP> or <SAMP>`-r'</SAMP> is supplied without a <VAR>name</VAR> -argument, an attempt is made to remove a completion specification for -a <VAR>name</VAR> for which no specification exists, or -an error occurs adding a completion specification. -</P><P> - -</DL> -<A NAME="IDX512"></A> -<P> - -<A NAME="Using History Interactively"></A> -<HR SIZE="6"> -<A NAME="SEC117"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC116"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC118"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 9. Using History Interactively </H1> -<!--docid::SEC117::--> -<P> - -This chapter describes how to use the GNU History Library -interactively, from a user's standpoint. -It should be considered a user's guide. -For information on using the GNU History Library in other programs, -see the GNU Readline Library Manual. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC118">9.1 Bash History Facilities</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How Bash lets you manipulate your command - history.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC119">9.2 Bash History Builtins</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">The Bash builtin commands that manipulate - the command history.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC120">9.3 History Expansion</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What it feels like using History as a user.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Bash History Facilities"></A> -<HR SIZE="6"> -<A NAME="SEC118"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC119"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 9.1 Bash History Facilities </H2> -<!--docid::SEC118::--> -<P> - -When the <SAMP>`-o history'</SAMP> option to the <CODE>set</CODE> builtin -is enabled (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>), -the shell provides access to the <EM>command history</EM>, -the list of commands previously typed. -The value of the <CODE>HISTSIZE</CODE> shell variable is used as the -number of commands to save in a history list. -The text of the last <CODE>$HISTSIZE</CODE> -commands (default 500) is saved. -The shell stores each command in the history list prior to -parameter and variable expansion -but after history expansion is performed, subject to the -values of the shell variables -<CODE>HISTIGNORE</CODE> and <CODE>HISTCONTROL</CODE>. -</P><P> - -When the shell starts up, the history is initialized from the -file named by the <CODE>HISTFILE</CODE> variable (default <TT>`~/.bash_history'</TT>). -The file named by the value of <CODE>HISTFILE</CODE> is truncated, if -necessary, to contain no more than the number of lines specified by -the value of the <CODE>HISTFILESIZE</CODE> variable. -When an interactive shell exits, the last -<CODE>$HISTSIZE</CODE> lines are copied from the history list to the file -named by <CODE>$HISTFILE</CODE>. -If the <CODE>histappend</CODE> shell option is set (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>), -the lines are appended to the history file, -otherwise the history file is overwritten. -If <CODE>HISTFILE</CODE> -is unset, or if the history file is unwritable, the history is -not saved. After saving the history, the history file is truncated -to contain no more than <CODE>$HISTFILESIZE</CODE> -lines. If <CODE>HISTFILESIZE</CODE> is not set, no truncation is performed. -</P><P> - -If the <CODE>HISTTIMEFORMAT</CODE> is set, the time stamp information -associated with each history entry is written to the history file. -</P><P> - -The builtin command <CODE>fc</CODE> may be used to list or edit and re-execute -a portion of the history list. -The <CODE>history</CODE> builtin may be used to display or modify the history -list and manipulate the history file. -When using command-line editing, search commands -are available in each editing mode that provide access to the -history list (see section <A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A>). -</P><P> - -The shell allows control over which commands are saved on the history -list. The <CODE>HISTCONTROL</CODE> and <CODE>HISTIGNORE</CODE> -variables may be set to cause the shell to save only a subset of the -commands entered. -The <CODE>cmdhist</CODE> -shell option, if enabled, causes the shell to attempt to save each -line of a multi-line command in the same history entry, adding -semicolons where necessary to preserve syntactic correctness. -The <CODE>lithist</CODE> -shell option causes the shell to save the command with embedded newlines -instead of semicolons. -The <CODE>shopt</CODE> builtin is used to set these options. -See section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>, for a description of <CODE>shopt</CODE>. -</P><P> - -<A NAME="Bash History Builtins"></A> -<HR SIZE="6"> -<A NAME="SEC119"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC118"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC120"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC120"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 9.2 Bash History Builtins </H2> -<!--docid::SEC119::--> -<P> - -Bash provides two builtin commands which manipulate the -history list and history file. -</P><P> - -<DL COMPACT> - -<DT><CODE>fc</CODE> -<DD><A NAME="IDX513"></A> -<TABLE><tr><td> </td><td class=example><pre><CODE>fc [-e <VAR>ename</VAR>] [-lnr] [<VAR>first</VAR>] [<VAR>last</VAR>]</CODE> -<CODE>fc -s [<VAR>pat</VAR>=<VAR>rep</VAR>] [<VAR>command</VAR>]</CODE> -</pre></td></tr></table><P> - -Fix Command. In the first form, a range of commands from <VAR>first</VAR> to -<VAR>last</VAR> is selected from the history list. Both <VAR>first</VAR> and -<VAR>last</VAR> may be specified as a string (to locate the most recent -command beginning with that string) or as a number (an index into the -history list, where a negative number is used as an offset from the -current command number). If <VAR>last</VAR> is not specified it is set to -<VAR>first</VAR>. If <VAR>first</VAR> is not specified it is set to the previous -command for editing and -16 for listing. If the <SAMP>`-l'</SAMP> flag is -given, the commands are listed on standard output. The <SAMP>`-n'</SAMP> flag -suppresses the command numbers when listing. The <SAMP>`-r'</SAMP> flag -reverses the order of the listing. Otherwise, the editor given by -<VAR>ename</VAR> is invoked on a file containing those commands. If -<VAR>ename</VAR> is not given, the value of the following variable expansion -is used: <CODE>${FCEDIT:-${EDITOR:-vi}}</CODE>. This says to use the -value of the <CODE>FCEDIT</CODE> variable if set, or the value of the -<CODE>EDITOR</CODE> variable if that is set, or <CODE>vi</CODE> if neither is set. -When editing is complete, the edited commands are echoed and executed. -</P><P> - -In the second form, <VAR>command</VAR> is re-executed after each instance -of <VAR>pat</VAR> in the selected command is replaced by <VAR>rep</VAR>. -</P><P> - -A useful alias to use with the <CODE>fc</CODE> command is <CODE>r='fc -s'</CODE>, so -that typing <SAMP>`r cc'</SAMP> runs the last command beginning with <CODE>cc</CODE> -and typing <SAMP>`r'</SAMP> re-executes the last command (see section <A HREF="b.html#SEC82">6.6 Aliases</A>). -</P><P> - -<DT><CODE>history</CODE> -<DD><A NAME="IDX514"></A> -<TABLE><tr><td> </td><td class=example><pre>history [<VAR>n</VAR>] -history -c -history -d <VAR>offset</VAR> -history [-anrw] [<VAR>filename</VAR>] -history -ps <VAR>arg</VAR> -</pre></td></tr></table><P> - -With no options, display the history list with line numbers. -Lines prefixed with a <SAMP>`*'</SAMP> have been modified. -An argument of <VAR>n</VAR> lists only the last <VAR>n</VAR> lines. -If the shell variable <CODE>HISTTIMEFORMAT</CODE> is set and not null, -it is used as a format string for <VAR>strftime</VAR> to display -the time stamp associated with each displayed history entry. -No intervening blank is printed between the formatted time stamp -and the history line. -</P><P> - -Options, if supplied, have the following meanings: -</P><P> - -<DL COMPACT> -<DT><CODE>-c</CODE> -<DD>Clear the history list. This may be combined -with the other options to replace the history list completely. -<P> - -<DT><CODE>-d <VAR>offset</VAR></CODE> -<DD>Delete the history entry at position <VAR>offset</VAR>. -<VAR>offset</VAR> should be specified as it appears when the history is -displayed. -<P> - -<DT><CODE>-a</CODE> -<DD>Append the new -history lines (history lines entered since the beginning of the -current Bash session) to the history file. -<P> - -<DT><CODE>-n</CODE> -<DD>Append the history lines not already read from the history file -to the current history list. These are lines appended to the history -file since the beginning of the current Bash session. -<P> - -<DT><CODE>-r</CODE> -<DD>Read the current history file and append its contents to -the history list. -<P> - -<DT><CODE>-w</CODE> -<DD>Write out the current history to the history file. -<P> - -<DT><CODE>-p</CODE> -<DD>Perform history substitution on the <VAR>arg</VAR>s and display the result -on the standard output, without storing the results in the history list. -<P> - -<DT><CODE>-s</CODE> -<DD>The <VAR>arg</VAR>s are added to the end of -the history list as a single entry. -<P> - -</DL> -<P> - -When any of the <SAMP>`-w'</SAMP>, <SAMP>`-r'</SAMP>, <SAMP>`-a'</SAMP>, or <SAMP>`-n'</SAMP> options is -used, if <VAR>filename</VAR> -is given, then it is used as the history file. If not, then -the value of the <CODE>HISTFILE</CODE> variable is used. -</P><P> - -</DL> -<P> - -<A NAME="History Interaction"></A> -<HR SIZE="6"> -<A NAME="SEC120"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC119"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC121"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC117"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 9.3 History Expansion </H2> -<!--docid::SEC120::--> -<P> - -The History library provides a history expansion feature that is similar -to the history expansion provided by <CODE>csh</CODE>. This section -describes the syntax used to manipulate the history information. -</P><P> - -History expansions introduce words from the history list into -the input stream, making it easy to repeat commands, insert the -arguments to a previous command into the current input line, or -fix errors in previous commands quickly. -</P><P> - -History expansion takes place in two parts. The first is to determine -which line from the history list should be used during substitution. -The second is to select portions of that line for inclusion into the -current one. The line selected from the history is called the -<EM>event</EM>, and the portions of that line that are acted upon are -called <EM>words</EM>. Various <EM>modifiers</EM> are available to manipulate -the selected words. The line is broken into words in the same fashion -that Bash does, so that several words -surrounded by quotes are considered one word. -History expansions are introduced by the appearance of the -history expansion character, which is <SAMP>`!'</SAMP> by default. -Only <SAMP>`\'</SAMP> and <SAMP>`''</SAMP> may be used to escape the history expansion -character. -</P><P> - -Several shell options settable with the <CODE>shopt</CODE> -builtin (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>) may be used to tailor -the behavior of history expansion. If the -<CODE>histverify</CODE> shell option is enabled, and Readline -is being used, history substitutions are not immediately passed to -the shell parser. -Instead, the expanded line is reloaded into the Readline -editing buffer for further modification. -If Readline is being used, and the <CODE>histreedit</CODE> -shell option is enabled, a failed history expansion will be -reloaded into the Readline editing buffer for correction. -The <SAMP>`-p'</SAMP> option to the <CODE>history</CODE> builtin command -may be used to see what a history expansion will do before using it. -The <SAMP>`-s'</SAMP> option to the <CODE>history</CODE> builtin may be used to -add commands to the end of the history list without actually executing -them, so that they are available for subsequent recall. -This is most useful in conjunction with Readline. -</P><P> - -The shell allows control of the various characters used by the -history expansion mechanism with the <CODE>histchars</CODE> variable. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC121">9.3.1 Event Designators</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to specify which history line to use.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC122">9.3.2 Word Designators</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Specifying which words are of interest.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC123">9.3.3 Modifiers</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Modifying the results of substitution.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Event Designators"></A> -<HR SIZE="6"> -<A NAME="SEC121"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC120"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC122"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC120"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 9.3.1 Event Designators </H3> -<!--docid::SEC121::--> -<P> - -An event designator is a reference to a command line entry in the -history list. -<A NAME="IDX515"></A> -</P><P> - -<DL COMPACT> - -<DT><CODE>!</CODE> -<DD>Start a history substitution, except when followed by a space, tab, -the end of the line, <SAMP>`='</SAMP> or <SAMP>`('</SAMP> (when the -<CODE>extglob</CODE> shell option is enabled using the <CODE>shopt</CODE> builtin). -<P> - -<DT><CODE>!<VAR>n</VAR></CODE> -<DD>Refer to command line <VAR>n</VAR>. -<P> - -<DT><CODE>!-<VAR>n</VAR></CODE> -<DD>Refer to the command <VAR>n</VAR> lines back. -<P> - -<DT><CODE>!!</CODE> -<DD>Refer to the previous command. This is a synonym for <SAMP>`!-1'</SAMP>. -<P> - -<DT><CODE>!<VAR>string</VAR></CODE> -<DD>Refer to the most recent command starting with <VAR>string</VAR>. -<P> - -<DT><CODE>!?<VAR>string</VAR>[?]</CODE> -<DD>Refer to the most recent command containing <VAR>string</VAR>. The trailing -<SAMP>`?'</SAMP> may be omitted if the <VAR>string</VAR> is followed immediately by -a newline. -<P> - -<DT><CODE>^<VAR>string1</VAR>^<VAR>string2</VAR>^</CODE> -<DD>Quick Substitution. Repeat the last command, replacing <VAR>string1</VAR> -with <VAR>string2</VAR>. Equivalent to -<CODE>!!:s/<VAR>string1</VAR>/<VAR>string2</VAR>/</CODE>. -<P> - -<DT><CODE>!#</CODE> -<DD>The entire command line typed so far. -<P> - -</DL> -<P> - -<A NAME="Word Designators"></A> -<HR SIZE="6"> -<A NAME="SEC122"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC121"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC123"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC123"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC120"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 9.3.2 Word Designators </H3> -<!--docid::SEC122::--> -<P> - -Word designators are used to select desired words from the event. -A <SAMP>`:'</SAMP> separates the event specification from the word designator. It -may be omitted if the word designator begins with a <SAMP>`^'</SAMP>, <SAMP>`$'</SAMP>, -<SAMP>`*'</SAMP>, <SAMP>`-'</SAMP>, or <SAMP>`%'</SAMP>. Words are numbered from the beginning -of the line, with the first word being denoted by 0 (zero). Words are -inserted into the current line separated by single spaces. -</P><P> - -For example, -</P><P> - -<DL COMPACT> -<DT><CODE>!!</CODE> -<DD>designates the preceding command. When you type this, the preceding -command is repeated in toto. -<P> - -<DT><CODE>!!:$</CODE> -<DD>designates the last argument of the preceding command. This may be -shortened to <CODE>!$</CODE>. -<P> - -<DT><CODE>!fi:2</CODE> -<DD>designates the second argument of the most recent command starting with -the letters <CODE>fi</CODE>. -</DL> -<P> - -Here are the word designators: - -<DL COMPACT> - -<DT><CODE>0 (zero)</CODE> -<DD>The <CODE>0</CODE>th word. For many applications, this is the command word. -<P> - -<DT><CODE><VAR>n</VAR></CODE> -<DD>The <VAR>n</VAR>th word. -<P> - -<DT><CODE>^</CODE> -<DD>The first argument; that is, word 1. -<P> - -<DT><CODE>$</CODE> -<DD>The last argument. -<P> - -<DT><CODE>%</CODE> -<DD>The word matched by the most recent <SAMP>`?<VAR>string</VAR>?'</SAMP> search. -<P> - -<DT><CODE><VAR>x</VAR>-<VAR>y</VAR></CODE> -<DD>A range of words; <SAMP>`-<VAR>y</VAR>'</SAMP> abbreviates <SAMP>`0-<VAR>y</VAR>'</SAMP>. -<P> - -<DT><CODE>*</CODE> -<DD>All of the words, except the <CODE>0</CODE>th. This is a synonym for <SAMP>`1-$'</SAMP>. -It is not an error to use <SAMP>`*'</SAMP> if there is just one word in the event; -the empty string is returned in that case. -<P> - -<DT><CODE><VAR>x</VAR>*</CODE> -<DD>Abbreviates <SAMP>`<VAR>x</VAR>-$'</SAMP> -<P> - -<DT><CODE><VAR>x</VAR>-</CODE> -<DD>Abbreviates <SAMP>`<VAR>x</VAR>-$'</SAMP> like <SAMP>`<VAR>x</VAR>*'</SAMP>, but omits the last word. -<P> - -</DL> -<P> - -If a word designator is supplied without an event specification, the -previous command is used as the event. -</P><P> - -<A NAME="Modifiers"></A> -<HR SIZE="6"> -<A NAME="SEC123"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC122"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC120"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H3> 9.3.3 Modifiers </H3> -<!--docid::SEC123::--> -<P> - -After the optional word designator, you can add a sequence of one or more -of the following modifiers, each preceded by a <SAMP>`:'</SAMP>. -</P><P> - -<DL COMPACT> - -<DT><CODE>h</CODE> -<DD>Remove a trailing pathname component, leaving only the head. -<P> - -<DT><CODE>t</CODE> -<DD>Remove all leading pathname components, leaving the tail. -<P> - -<DT><CODE>r</CODE> -<DD>Remove a trailing suffix of the form <SAMP>`.<VAR>suffix</VAR>'</SAMP>, leaving -the basename. -<P> - -<DT><CODE>e</CODE> -<DD>Remove all but the trailing suffix. -<P> - -<DT><CODE>p</CODE> -<DD>Print the new command but do not execute it. -<P> - -<DT><CODE>q</CODE> -<DD>Quote the substituted words, escaping further substitutions. -<P> - -<DT><CODE>x</CODE> -<DD>Quote the substituted words as with <SAMP>`q'</SAMP>, -but break into words at spaces, tabs, and newlines. -<P> - -<DT><CODE>s/<VAR>old</VAR>/<VAR>new</VAR>/</CODE> -<DD>Substitute <VAR>new</VAR> for the first occurrence of <VAR>old</VAR> in the -event line. Any delimiter may be used in place of <SAMP>`/'</SAMP>. -The delimiter may be quoted in <VAR>old</VAR> and <VAR>new</VAR> -with a single backslash. If <SAMP>`&'</SAMP> appears in <VAR>new</VAR>, -it is replaced by <VAR>old</VAR>. A single backslash will quote -the <SAMP>`&'</SAMP>. The final delimiter is optional if it is the last -character on the input line. -<P> - -<DT><CODE>&</CODE> -<DD>Repeat the previous substitution. -<P> - -<DT><CODE>g</CODE> -<DD><DT><CODE>a</CODE> -<DD>Cause changes to be applied over the entire event line. Used in -conjunction with <SAMP>`s'</SAMP>, as in <CODE>gs/<VAR>old</VAR>/<VAR>new</VAR>/</CODE>, -or with <SAMP>`&'</SAMP>. -<P> - -<DT><CODE>G</CODE> -<DD>Apply the following <SAMP>`s'</SAMP> modifier once to each word in the event. -<P> - -</DL> -<P> - -<A NAME="Installing Bash"></A> -<HR SIZE="6"> -<A NAME="SEC124"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC123"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC125"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC4"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> 10. Installing Bash </H1> -<!--docid::SEC124::--> -<P> - -This chapter provides basic instructions for installing Bash on -the various supported platforms. The distribution supports the -GNU operating systems, nearly every version of Unix, and several -non-Unix systems such as BeOS and Interix. -Other independent ports exist for -MS-DOS, OS/2, and Windows platforms. -</P><P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC125">10.1 Basic Installation</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Installation instructions.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC126">10.2 Compilers and Options</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to set special options for various - systems.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC127">10.3 Compiling For Multiple Architectures</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to compile Bash for more - than one kind of system from - the same source tree.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC128">10.4 Installation Names</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to set the various paths used by the installation.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC129">10.5 Specifying the System Type</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to configure Bash for a particular system.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC130">10.6 Sharing Defaults</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to share default configuration values among GNU - programs.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC131">10.7 Operation Controls</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Options recognized by the configuration program.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC132">10.8 Optional Features</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">How to enable and disable optional features when - building Bash.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Basic Installation"></A> -<HR SIZE="6"> -<A NAME="SEC125"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC126"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.1 Basic Installation </H2> -<!--docid::SEC125::--> -<P> - -These are installation instructions for Bash. -</P><P> - -The simplest way to compile Bash is: -</P><P> - -<OL> -<LI> -<CODE>cd</CODE> to the directory containing the source code and type -<SAMP>`./configure'</SAMP> to configure Bash for your system. If you're -using <CODE>csh</CODE> on an old version of System V, you might need to -type <SAMP>`sh ./configure'</SAMP> instead to prevent <CODE>csh</CODE> from trying -to execute <CODE>configure</CODE> itself. -<P> - -Running <CODE>configure</CODE> takes some time. -While running, it prints messages telling which features it is -checking for. -</P><P> - -<LI> -Type <SAMP>`make'</SAMP> to compile Bash and build the <CODE>bashbug</CODE> bug -reporting script. -<P> - -<LI> -Optionally, type <SAMP>`make tests'</SAMP> to run the Bash test suite. -<P> - -<LI> -Type <SAMP>`make install'</SAMP> to install <CODE>bash</CODE> and <CODE>bashbug</CODE>. -This will also install the manual pages and Info file. -<P> - -</OL> -<P> - -The <CODE>configure</CODE> shell script attempts to guess correct -values for various system-dependent variables used during -compilation. It uses those values to create a <TT>`Makefile'</TT> in -each directory of the package (the top directory, the -<TT>`builtins'</TT>, <TT>`doc'</TT>, and <TT>`support'</TT> directories, -each directory under <TT>`lib'</TT>, and several others). It also creates a -<TT>`config.h'</TT> file containing system-dependent definitions. -Finally, it creates a shell script named <CODE>config.status</CODE> that you -can run in the future to recreate the current configuration, a -file <TT>`config.cache'</TT> that saves the results of its tests to -speed up reconfiguring, and a file <TT>`config.log'</TT> containing -compiler output (useful mainly for debugging <CODE>configure</CODE>). -If at some point -<TT>`config.cache'</TT> contains results you don't want to keep, you -may remove or edit it. -</P><P> - -To find out more about the options and arguments that the -<CODE>configure</CODE> script understands, type -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>bash-2.04$ ./configure --help -</pre></td></tr></table></P><P> - -at the Bash prompt in your Bash source directory. -</P><P> - -If you need to do unusual things to compile Bash, please -try to figure out how <CODE>configure</CODE> could check whether or not -to do them, and mail diffs or instructions to -<A HREF="mailto:bash-maintainers@gnu.org">bash-maintainers@gnu.org</A> so they can be -considered for the next release. -</P><P> - -The file <TT>`configure.in'</TT> is used to create <CODE>configure</CODE> -by a program called Autoconf. You only need -<TT>`configure.in'</TT> if you want to change it or regenerate -<CODE>configure</CODE> using a newer version of Autoconf. If -you do this, make sure you are using Autoconf version 2.50 or -newer. -</P><P> - -You can remove the program binaries and object files from the -source code directory by typing <SAMP>`make clean'</SAMP>. To also remove the -files that <CODE>configure</CODE> created (so you can compile Bash for -a different kind of computer), type <SAMP>`make distclean'</SAMP>. -</P><P> - -<A NAME="Compilers and Options"></A> -<HR SIZE="6"> -<A NAME="SEC126"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC125"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC127"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC127"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.2 Compilers and Options </H2> -<!--docid::SEC126::--> -<P> - -Some systems require unusual options for compilation or linking -that the <CODE>configure</CODE> script does not know about. You can -give <CODE>configure</CODE> initial values for variables by setting -them in the environment. Using a Bourne-compatible shell, you -can do that on the command line like this: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>CC=c89 CFLAGS=-O2 LIBS=-lposix ./configure -</pre></td></tr></table></P><P> - -On systems that have the <CODE>env</CODE> program, you can do it like this: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>env CPPFLAGS=-I/usr/local/include LDFLAGS=-s ./configure -</pre></td></tr></table></P><P> - -The configuration process uses GCC to build Bash if it -is available. -</P><P> - -<A NAME="Compiling For Multiple Architectures"></A> -<HR SIZE="6"> -<A NAME="SEC127"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC126"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC128"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC128"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.3 Compiling For Multiple Architectures </H2> -<!--docid::SEC127::--> -<P> - -You can compile Bash for more than one kind of computer at the -same time, by placing the object files for each architecture in their -own directory. To do this, you must use a version of <CODE>make</CODE> that -supports the <CODE>VPATH</CODE> variable, such as GNU <CODE>make</CODE>. -<CODE>cd</CODE> to the -directory where you want the object files and executables to go and run -the <CODE>configure</CODE> script from the source directory. You may need to -supply the <SAMP>`--srcdir=PATH'</SAMP> argument to tell <CODE>configure</CODE> where the -source files are. <CODE>configure</CODE> automatically checks for the -source code in the directory that <CODE>configure</CODE> is in and in `..'. -</P><P> - -If you have to use a <CODE>make</CODE> that does not supports the <CODE>VPATH</CODE> -variable, you can compile Bash for one architecture at a -time in the source code directory. After you have installed -Bash for one architecture, use <SAMP>`make distclean'</SAMP> before -reconfiguring for another architecture. -</P><P> - -Alternatively, if your system supports symbolic links, you can use the -<TT>`support/mkclone'</TT> script to create a build tree which has -symbolic links back to each file in the source directory. Here's an -example that creates a build directory in the current directory from a -source directory <TT>`/usr/gnu/src/bash-2.0'</TT>: -</P><P> - -<TABLE><tr><td> </td><td class=example><pre>bash /usr/gnu/src/bash-2.0/support/mkclone -s /usr/gnu/src/bash-2.0 . -</pre></td></tr></table></P><P> - -The <CODE>mkclone</CODE> script requires Bash, so you must have already built -Bash for at least one architecture before you can create build -directories for other architectures. -</P><P> - -<A NAME="Installation Names"></A> -<HR SIZE="6"> -<A NAME="SEC128"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC127"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC129"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC129"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.4 Installation Names </H2> -<!--docid::SEC128::--> -<P> - -By default, <SAMP>`make install'</SAMP> will install into -<TT>`/usr/local/bin'</TT>, <TT>`/usr/local/man'</TT>, etc. You can -specify an installation prefix other than <TT>`/usr/local'</TT> by -giving <CODE>configure</CODE> the option <SAMP>`--prefix=<VAR>PATH</VAR>'</SAMP>, -or by specifying a value for the <CODE>DESTDIR</CODE> <SAMP>`make'</SAMP> -variable when running <SAMP>`make install'</SAMP>. -</P><P> - -You can specify separate installation prefixes for -architecture-specific files and architecture-independent files. -If you give <CODE>configure</CODE> the option -<SAMP>`--exec-prefix=<VAR>PATH</VAR>'</SAMP>, <SAMP>`make install'</SAMP> will use -<VAR>PATH</VAR> as the prefix for installing programs and libraries. -Documentation and other data files will still use the regular prefix. -</P><P> - -<A NAME="Specifying the System Type"></A> -<HR SIZE="6"> -<A NAME="SEC129"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC128"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC130"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC130"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.5 Specifying the System Type </H2> -<!--docid::SEC129::--> -<P> - -There may be some features <CODE>configure</CODE> can not figure out -automatically, but need to determine by the type of host Bash -will run on. Usually <CODE>configure</CODE> can figure that -out, but if it prints a message saying it can not guess the host -type, give it the <SAMP>`--host=TYPE'</SAMP> option. <SAMP>`TYPE'</SAMP> can -either be a short name for the system type, such as <SAMP>`sun4'</SAMP>, -or a canonical name with three fields: <SAMP>`CPU-COMPANY-SYSTEM'</SAMP> -(e.g., <SAMP>`i386-unknown-freebsd4.2'</SAMP>). -</P><P> - -See the file <TT>`support/config.sub'</TT> for the possible -values of each field. -</P><P> - -<A NAME="Sharing Defaults"></A> -<HR SIZE="6"> -<A NAME="SEC130"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC129"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC131"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC131"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.6 Sharing Defaults </H2> -<!--docid::SEC130::--> -<P> - -If you want to set default values for <CODE>configure</CODE> scripts to -share, you can create a site shell script called -<CODE>config.site</CODE> that gives default values for variables like -<CODE>CC</CODE>, <CODE>cache_file</CODE>, and <CODE>prefix</CODE>. <CODE>configure</CODE> -looks for <TT>`PREFIX/share/config.site'</TT> if it exists, then -<TT>`PREFIX/etc/config.site'</TT> if it exists. Or, you can set the -<CODE>CONFIG_SITE</CODE> environment variable to the location of the site -script. A warning: the Bash <CODE>configure</CODE> looks for a site script, -but not all <CODE>configure</CODE> scripts do. -</P><P> - -<A NAME="Operation Controls"></A> -<HR SIZE="6"> -<A NAME="SEC131"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC130"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC132"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC132"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.7 Operation Controls </H2> -<!--docid::SEC131::--> -<P> - -<CODE>configure</CODE> recognizes the following options to control how it -operates. -</P><P> - -<DL COMPACT> - -<DT><CODE>--cache-file=<VAR>file</VAR></CODE> -<DD>Use and save the results of the tests in -<VAR>file</VAR> instead of <TT>`./config.cache'</TT>. Set <VAR>file</VAR> to -<TT>`/dev/null'</TT> to disable caching, for debugging -<CODE>configure</CODE>. -<P> - -<DT><CODE>--help</CODE> -<DD>Print a summary of the options to <CODE>configure</CODE>, and exit. -<P> - -<DT><CODE>--quiet</CODE> -<DD><DT><CODE>--silent</CODE> -<DD><DT><CODE>-q</CODE> -<DD>Do not print messages saying which checks are being made. -<P> - -<DT><CODE>--srcdir=<VAR>dir</VAR></CODE> -<DD>Look for the Bash source code in directory <VAR>dir</VAR>. Usually -<CODE>configure</CODE> can determine that directory automatically. -<P> - -<DT><CODE>--version</CODE> -<DD>Print the version of Autoconf used to generate the <CODE>configure</CODE> -script, and exit. -</DL> -<P> - -<CODE>configure</CODE> also accepts some other, not widely used, boilerplate -options. <SAMP>`configure --help'</SAMP> prints the complete list. -</P><P> - -<A NAME="Optional Features"></A> -<HR SIZE="6"> -<A NAME="SEC132"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC131"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> 10.8 Optional Features </H2> -<!--docid::SEC132::--> -<P> - -The Bash <CODE>configure</CODE> has a number of <SAMP>`--enable-<VAR>feature</VAR>'</SAMP> -options, where <VAR>feature</VAR> indicates an optional part of Bash. -There are also several <SAMP>`--with-<VAR>package</VAR>'</SAMP> options, -where <VAR>package</VAR> is something like <SAMP>`bash-malloc'</SAMP> or <SAMP>`purify'</SAMP>. -To turn off the default use of a package, use -<SAMP>`--without-<VAR>package</VAR>'</SAMP>. To configure Bash without a feature -that is enabled by default, use <SAMP>`--disable-<VAR>feature</VAR>'</SAMP>. -</P><P> - -Here is a complete list of the <SAMP>`--enable-'</SAMP> and -<SAMP>`--with-'</SAMP> options that the Bash <CODE>configure</CODE> recognizes. -</P><P> - -<DL COMPACT> -<DT><CODE>--with-afs</CODE> -<DD>Define if you are using the Andrew File System from Transarc. -<P> - -<DT><CODE>--with-bash-malloc</CODE> -<DD>Use the Bash version of -<CODE>malloc</CODE> in the directory <TT>`lib/malloc'</TT>. This is not the same -<CODE>malloc</CODE> that appears in GNU libc, but an older version -originally derived from the 4.2 BSD <CODE>malloc</CODE>. This <CODE>malloc</CODE> -is very fast, but wastes some space on each allocation. -This option is enabled by default. -The <TT>`NOTES'</TT> file contains a list of systems for -which this should be turned off, and <CODE>configure</CODE> disables this -option automatically for a number of systems. -<P> - -<DT><CODE>--with-curses</CODE> -<DD>Use the curses library instead of the termcap library. This should -be supplied if your system has an inadequate or incomplete termcap -database. -<P> - -<DT><CODE>--with-gnu-malloc</CODE> -<DD>A synonym for <CODE>--with-bash-malloc</CODE>. -<P> - -<DT><CODE>--with-installed-readline[=<VAR>PREFIX</VAR>]</CODE> -<DD>Define this to make Bash link with a locally-installed version of Readline -rather than the version in <TT>`lib/readline'</TT>. This works only with -Readline 5.0 and later versions. If <VAR>PREFIX</VAR> is <CODE>yes</CODE> or not -supplied, <CODE>configure</CODE> uses the values of the make variables -<CODE>includedir</CODE> and <CODE>libdir</CODE>, which are subdirectories of <CODE>prefix</CODE> -by default, to find the installed version of Readline if it is not in -the standard system include and library directories. -If <VAR>PREFIX</VAR> is <CODE>no</CODE>, Bash links with the version in -<TT>`lib/readline'</TT>. -If <VAR>PREFIX</VAR> is set to any other value, <CODE>configure</CODE> treats it as -a directory pathname and looks for -the installed version of Readline in subdirectories of that directory -(include files in <VAR>PREFIX</VAR>/<CODE>include</CODE> and the library in -<VAR>PREFIX</VAR>/<CODE>lib</CODE>). -<P> - -<DT><CODE>--with-purify</CODE> -<DD>Define this to use the Purify memory allocation checker from Rational -Software. -<P> - -<DT><CODE>--enable-minimal-config</CODE> -<DD>This produces a shell with minimal features, close to the historical -Bourne shell. -</DL> -<P> - -There are several <SAMP>`--enable-'</SAMP> options that alter how Bash is -compiled and linked, rather than changing run-time features. -</P><P> - -<DL COMPACT> -<DT><CODE>--enable-largefile</CODE> -<DD>Enable support for <A HREF="http://www.sas.com/standards/large_file/x_open.20Mar96.html">large files</A> if the operating system requires special compiler options -to build programs which can access large files. This is enabled by -default, if the operating system provides large file support. -<P> - -<DT><CODE>--enable-profiling</CODE> -<DD>This builds a Bash binary that produces profiling information to be -processed by <CODE>gprof</CODE> each time it is executed. -<P> - -<DT><CODE>--enable-static-link</CODE> -<DD>This causes Bash to be linked statically, if <CODE>gcc</CODE> is being used. -This could be used to build a version to use as root's shell. -</DL> -<P> - -The <SAMP>`minimal-config'</SAMP> option can be used to disable all of -the following options, but it is processed first, so individual -options may be enabled using <SAMP>`enable-<VAR>feature</VAR>'</SAMP>. -</P><P> - -All of the following options except for <SAMP>`disabled-builtins'</SAMP> and -<SAMP>`xpg-echo-default'</SAMP> are -enabled by default, unless the operating system does not provide the -necessary support. -</P><P> - -<DL COMPACT> -<DT><CODE>--enable-alias</CODE> -<DD>Allow alias expansion and include the <CODE>alias</CODE> and <CODE>unalias</CODE> -builtins (see section <A HREF="b.html#SEC82">6.6 Aliases</A>). -<P> - -<DT><CODE>--enable-arith-for-command</CODE> -<DD>Include support for the alternate form of the <CODE>for</CODE> command -that behaves like the C language <CODE>for</CODE> statement -(see section <A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A>). -<P> - -<DT><CODE>--enable-array-variables</CODE> -<DD>Include support for one-dimensional array shell variables -(see section <A HREF="b.html#SEC83">6.7 Arrays</A>). -<P> - -<DT><CODE>--enable-bang-history</CODE> -<DD>Include support for <CODE>csh</CODE>-like history substitution -(see section <A HREF="b.html#SEC120">9.3 History Expansion</A>). -<P> - -<DT><CODE>--enable-brace-expansion</CODE> -<DD>Include <CODE>csh</CODE>-like brace expansion -( <CODE>b{a,b}c</CODE> ==> <CODE>bac bbc</CODE> ). -See <A HREF="b.html#SEC28">3.5.1 Brace Expansion</A>, for a complete description. -<P> - -<DT><CODE>--enable-command-timing</CODE> -<DD>Include support for recognizing <CODE>time</CODE> as a reserved word and for -displaying timing statistics for the pipeline following <CODE>time</CODE> -(see section <A HREF="b.html#SEC17">3.2.2 Pipelines</A>). -This allows pipelines as well as shell builtins and functions to be timed. -<P> - -<DT><CODE>--enable-cond-command</CODE> -<DD>Include support for the <CODE>[[</CODE> conditional command. -(see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>). -<P> - -<DT><CODE>--enable-cond-regexp</CODE> -<DD>Include support for matching POSIX regular expressions using the -<SAMP>`=~'</SAMP> binary operator in the <CODE>[[</CODE> conditional command. -(see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>). -<P> - -<DT><CODE>--enable-debugger</CODE> -<DD>Include support for the bash debugger (distributed separately). -<P> - -<DT><CODE>--enable-directory-stack</CODE> -<DD>Include support for a <CODE>csh</CODE>-like directory stack and the -<CODE>pushd</CODE>, <CODE>popd</CODE>, and <CODE>dirs</CODE> builtins -(see section <A HREF="b.html#SEC84">6.8 The Directory Stack</A>). -<P> - -<DT><CODE>--enable-disabled-builtins</CODE> -<DD>Allow builtin commands to be invoked via <SAMP>`builtin xxx'</SAMP> -even after <CODE>xxx</CODE> has been disabled using <SAMP>`enable -n xxx'</SAMP>. -See <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>, for details of the <CODE>builtin</CODE> and -<CODE>enable</CODE> builtin commands. -<P> - -<DT><CODE>--enable-dparen-arithmetic</CODE> -<DD>Include support for the <CODE>((<small>...</small>))</CODE> command -(see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>). -<P> - -<DT><CODE>--enable-extended-glob</CODE> -<DD>Include support for the extended pattern matching features described -above under <A HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A>. -<P> - -<DT><CODE>--enable-help-builtin</CODE> -<DD>Include the <CODE>help</CODE> builtin, which displays help on shell builtins and -variables (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<DT><CODE>--enable-history</CODE> -<DD>Include command history and the <CODE>fc</CODE> and <CODE>history</CODE> -builtin commands (see section <A HREF="b.html#SEC118">9.1 Bash History Facilities</A>). -<P> - -<DT><CODE>--enable-job-control</CODE> -<DD>This enables the job control features (see section <A HREF="b.html#SEC89">7. Job Control</A>), -if the operating system supports them. -<P> - -<DT><CODE>--enable-multibyte</CODE> -<DD>This enables support for multibyte characters if the operating -system provides the necessary support. -<P> - -<DT><CODE>--enable-net-redirections</CODE> -<DD>This enables the special handling of filenames of the form -<CODE>/dev/tcp/<VAR>host</VAR>/<VAR>port</VAR></CODE> and -<CODE>/dev/udp/<VAR>host</VAR>/<VAR>port</VAR></CODE> -when used in redirections (see section <A HREF="b.html#SEC38">3.6 Redirections</A>). -<P> - -<DT><CODE>--enable-process-substitution</CODE> -<DD>This enables process substitution (see section <A HREF="b.html#SEC33">3.5.6 Process Substitution</A>) if -the operating system provides the necessary support. -<P> - -<DT><CODE>--enable-progcomp</CODE> -<DD>Enable the programmable completion facilities -(see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>). -If Readline is not enabled, this option has no effect. -<P> - -<DT><CODE>--enable-prompt-string-decoding</CODE> -<DD>Turn on the interpretation of a number of backslash-escaped characters -in the <CODE>$PS1</CODE>, <CODE>$PS2</CODE>, <CODE>$PS3</CODE>, and <CODE>$PS4</CODE> prompt -strings. See <A HREF="b.html#SEC86">6.9 Controlling the Prompt</A>, for a complete list of prompt -string escape sequences. -<P> - -<DT><CODE>--enable-readline</CODE> -<DD>Include support for command-line editing and history with the Bash -version of the Readline library (see section <A HREF="b.html#SEC93">8. Command Line Editing</A>). -<P> - -<DT><CODE>--enable-restricted</CODE> -<DD>Include support for a <EM>restricted shell</EM>. If this is enabled, Bash, -when called as <CODE>rbash</CODE>, enters a restricted mode. See -<A HREF="b.html#SEC87">6.10 The Restricted Shell</A>, for a description of restricted mode. -<P> - -<DT><CODE>--enable-select</CODE> -<DD>Include the <CODE>select</CODE> builtin, which allows the generation of simple -menus (see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>). -<P> - -<DT><CODE>--enable-separate-helpfiles</CODE> -<DD>Use external files for the documentation displayed by the <CODE>help</CODE> builtin -instead of storing the text internally. -<P> - -<DT><CODE>--enable-single-help-strings</CODE> -<DD>Store the text displayed by the <CODE>help</CODE> builtin as a single string for -each help topic. This aids in translating the text to different languages. -You may need to disable this if your compiler cannot handle very long string -literals. -<P> - -<DT><CODE>--enable-strict-posix-default</CODE> -<DD>Make Bash POSIX-conformant by default (see section <A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A>). -<P> - -<DT><CODE>--enable-usg-echo-default</CODE> -<DD>A synonym for <CODE>--enable-xpg-echo-default</CODE>. -<P> - -<DT><CODE>--enable-xpg-echo-default</CODE> -<DD>Make the <CODE>echo</CODE> builtin expand backslash-escaped characters by default, -without requiring the <SAMP>`-e'</SAMP> option. -This sets the default value of the <CODE>xpg_echo</CODE> shell option to <CODE>on</CODE>, -which makes the Bash <CODE>echo</CODE> behave more like the version specified in -the Single Unix Specification, version 3. -See section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>, for a description of the escape sequences that -<CODE>echo</CODE> recognizes. -<P> - -</DL> -<P> - -The file <TT>`config-top.h'</TT> contains C Preprocessor -<SAMP>`#define'</SAMP> statements for options which are not settable from -<CODE>configure</CODE>. -Some of these are not meant to be changed; beware of the consequences if -you do. -Read the comments associated with each definition for more -information about its effect. -</P><P> - -<A NAME="Reporting Bugs"></A> -<HR SIZE="6"> -<A NAME="SEC133"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC132"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC134"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC124"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC134"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> A. Reporting Bugs </H1> -<!--docid::SEC133::--> -<P> - -Please report all bugs you find in Bash. -But first, you should -make sure that it really is a bug, and that it appears in the latest -version of Bash. -The latest version of Bash is always available for FTP from -<A HREF="ftp://ftp.gnu.org/pub/bash/">ftp://ftp.gnu.org/pub/bash/</A>. -</P><P> - -Once you have determined that a bug actually exists, use the -<CODE>bashbug</CODE> command to submit a bug report. -If you have a fix, you are encouraged to mail that as well! -Suggestions and `philosophical' bug reports may be mailed -to <A HREF="mailto:bug-bash@gnu.org">bug-bash@gnu.org</A> or posted to the Usenet -newsgroup <CODE>gnu.bash.bug</CODE>. -</P><P> - -All bug reports should include: -<UL> -<LI> -The version number of Bash. -<LI> -The hardware and operating system. -<LI> -The compiler used to compile Bash. -<LI> -A description of the bug behaviour. -<LI> -A short script or `recipe' which exercises the bug and may be used -to reproduce it. -</UL> -<P> - -<CODE>bashbug</CODE> inserts the first three items automatically into -the template it provides for filing a bug report. -</P><P> - -Please send all reports concerning this manual to -<A HREF="mailto:chet@po.CWRU.Edu">chet@po.CWRU.Edu</A>. -</P><P> - -<A NAME="Major Differences From The Bourne Shell"></A> -<HR SIZE="6"> -<A NAME="SEC134"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC133"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC135"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC136"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC136"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> B. Major Differences From The Bourne Shell </H1> -<!--docid::SEC134::--> -<P> - -Bash implements essentially the same grammar, parameter and -variable expansion, redirection, and quoting as the Bourne Shell. -Bash uses the POSIX standard as the specification of -how these features are to be implemented. There are some -differences between the traditional Bourne shell and Bash; this -section quickly details the differences of significance. A -number of these differences are explained in greater depth in -previous sections. -This section uses the version of <CODE>sh</CODE> included in SVR4.2 (the -last version of the historical Bourne shell) as the baseline reference. -</P><P> - -<UL> - -<LI> -Bash is POSIX-conformant, even where the POSIX specification -differs from traditional <CODE>sh</CODE> behavior (see section <A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A>). -<P> - -<LI> -Bash has multi-character invocation options (see section <A HREF="b.html#SEC67">6.1 Invoking Bash</A>). -<P> - -<LI> -Bash has command-line editing (see section <A HREF="b.html#SEC93">8. Command Line Editing</A>) and -the <CODE>bind</CODE> builtin. -<P> - -<LI> -Bash provides a programmable word completion mechanism -(see section <A HREF="b.html#SEC115">8.6 Programmable Completion</A>), and two builtin commands, -<CODE>complete</CODE> and <CODE>compgen</CODE>, to manipulate it. -<P> - -<LI> -Bash has command history (see section <A HREF="b.html#SEC118">9.1 Bash History Facilities</A>) and the -<CODE>history</CODE> and <CODE>fc</CODE> builtins to manipulate it. -The Bash history list maintains timestamp information and uses the -value of the <CODE>HISTTIMEFORMAT</CODE> variable to display it. -<P> - -<LI> -Bash implements <CODE>csh</CODE>-like history expansion -(see section <A HREF="b.html#SEC120">9.3 History Expansion</A>). -<P> - -<LI> -Bash has one-dimensional array variables (see section <A HREF="b.html#SEC83">6.7 Arrays</A>), and the -appropriate variable expansions and assignment syntax to use them. -Several of the Bash builtins take options to act on arrays. -Bash provides a number of built-in array variables. -<P> - -<LI> -The <CODE>$'<small>...</small>'</CODE> quoting syntax, which expands ANSI-C -backslash-escaped characters in the text between the single quotes, -is supported (see section <A HREF="b.html#SEC12">3.1.2.4 ANSI-C Quoting</A>). -<P> - -<LI> -Bash supports the <CODE>$"<small>...</small>"</CODE> quoting syntax to do -locale-specific translation of the characters between the double -quotes. The <SAMP>`-D'</SAMP>, <SAMP>`--dump-strings'</SAMP>, and <SAMP>`--dump-po-strings'</SAMP> -invocation options list the translatable strings found in a script -(see section <A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A>). -<P> - -<LI> -Bash implements the <CODE>!</CODE> keyword to negate the return value of -a pipeline (see section <A HREF="b.html#SEC17">3.2.2 Pipelines</A>). -Very useful when an <CODE>if</CODE> statement needs to act only if a test fails. -The Bash <SAMP>`-o pipefail'</SAMP> option to <CODE>set</CODE> will cause a pipeline to -return a failure status if any command fails. -<P> - -<LI> -Bash has the <CODE>time</CODE> reserved word and command timing (see section <A HREF="b.html#SEC17">3.2.2 Pipelines</A>). -The display of the timing statistics may be controlled with the -<CODE>TIMEFORMAT</CODE> variable. -<P> - -<LI> -Bash implements the <CODE>for (( <VAR>expr1</VAR> ; <VAR>expr2</VAR> ; <VAR>expr3</VAR> ))</CODE> -arithmetic for command, similar to the C language (see section <A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A>). -<P> - -<LI> -Bash includes the <CODE>select</CODE> compound command, which allows the -generation of simple menus (see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>). -<P> - -<LI> -Bash includes the <CODE>[[</CODE> compound command, which makes conditional -testing part of the shell grammar (see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>), including -optional regular expression matching. -<P> - -<LI> -Bash provides optional case-insensitive matching for the <CODE>case</CODE> and -<CODE>[[</CODE> constructs. -<P> - -<LI> -Bash includes brace expansion (see section <A HREF="b.html#SEC28">3.5.1 Brace Expansion</A>) and tilde -expansion (see section <A HREF="b.html#SEC29">3.5.2 Tilde Expansion</A>). -<P> - -<LI> -Bash implements command aliases and the <CODE>alias</CODE> and <CODE>unalias</CODE> -builtins (see section <A HREF="b.html#SEC82">6.6 Aliases</A>). -<P> - -<LI> -Bash provides shell arithmetic, the <CODE>((</CODE> compound command -(see section <A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A>), -and arithmetic expansion (see section <A HREF="b.html#SEC81">6.5 Shell Arithmetic</A>). -<P> - -<LI> -Variables present in the shell's initial environment are automatically -exported to child processes. The Bourne shell does not normally do -this unless the variables are explicitly marked using the <CODE>export</CODE> -command. -<P> - -<LI> -Bash supports the <SAMP>`+='</SAMP> assignment operator, which appends to the value -of the variable named on the left hand side. -<P> - -<LI> -Bash includes the POSIX pattern removal <SAMP>`%'</SAMP>, <SAMP>`#'</SAMP>, <SAMP>`%%'</SAMP> -and <SAMP>`##'</SAMP> expansions to remove leading or trailing substrings from -variable values (see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -<P> - -<LI> -The expansion <CODE>${#xx}</CODE>, which returns the length of <CODE>${xx}</CODE>, -is supported (see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -<P> - -<LI> -The expansion <CODE>${var:</CODE><VAR>offset</VAR><CODE>[:</CODE><VAR>length</VAR><CODE>]}</CODE>, -which expands to the substring of <CODE>var</CODE>'s value of length -<VAR>length</VAR>, beginning at <VAR>offset</VAR>, is present -(see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -<P> - -<LI> -The expansion -<CODE>${var/[/]</CODE><VAR>pattern</VAR><CODE>[/</CODE><VAR>replacement</VAR><CODE>]}</CODE>, -which matches <VAR>pattern</VAR> and replaces it with <VAR>replacement</VAR> in -the value of <CODE>var</CODE>, is available (see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -<P> - -<LI> -The expansion <CODE>${!<VAR>prefix}*</VAR></CODE> expansion, which expands to -the names of all shell variables whose names begin with <VAR>prefix</VAR>, -is available (see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -<P> - -<LI> -Bash has <VAR>indirect</VAR> variable expansion using <CODE>${!word}</CODE> -(see section <A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A>). -<P> - -<LI> -Bash can expand positional parameters beyond <CODE>$9</CODE> using -<CODE>${<VAR>num</VAR>}</CODE>. -<P> - -<LI> -The POSIX <CODE>$()</CODE> form of command substitution -is implemented (see section <A HREF="b.html#SEC31">3.5.4 Command Substitution</A>), -and preferred to the Bourne shell's <CODE>"</CODE> (which -is also implemented for backwards compatibility). -<P> - -<LI> -Bash has process substitution (see section <A HREF="b.html#SEC33">3.5.6 Process Substitution</A>). -<P> - -<LI> -Bash automatically assigns variables that provide information about the -current user (<CODE>UID</CODE>, <CODE>EUID</CODE>, and <CODE>GROUPS</CODE>), the current host -(<CODE>HOSTTYPE</CODE>, <CODE>OSTYPE</CODE>, <CODE>MACHTYPE</CODE>, and <CODE>HOSTNAME</CODE>), -and the instance of Bash that is running (<CODE>BASH</CODE>, -<CODE>BASH_VERSION</CODE>, and <CODE>BASH_VERSINFO</CODE>). See section <A HREF="b.html#SEC65">5.2 Bash Variables</A>, -for details. -<P> - -<LI> -The <CODE>IFS</CODE> variable is used to split only the results of expansion, -not all words (see section <A HREF="b.html#SEC34">3.5.7 Word Splitting</A>). -This closes a longstanding shell security hole. -<P> - -<LI> -Bash implements the full set of POSIX filename expansion operators, -including <VAR>character classes</VAR>, <VAR>equivalence classes</VAR>, and -<VAR>collating symbols</VAR> (see section <A HREF="b.html#SEC35">3.5.8 Filename Expansion</A>). -<P> - -<LI> -Bash implements extended pattern matching features when the <CODE>extglob</CODE> -shell option is enabled (see section <A HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A>). -<P> - -<LI> -It is possible to have a variable and a function with the same name; -<CODE>sh</CODE> does not separate the two name spaces. -<P> - -<LI> -Bash functions are permitted to have local variables using the -<CODE>local</CODE> builtin, and thus useful recursive functions may be written -(see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<LI> -Variable assignments preceding commands affect only that command, even -builtins and functions (see section <A HREF="b.html#SEC52">3.7.4 Environment</A>). -In <CODE>sh</CODE>, all variable assignments -preceding commands are global unless the command is executed from the -file system. -<P> - -<LI> -Bash performs filename expansion on filenames specified as operands -to input and output redirection operators (see section <A HREF="b.html#SEC38">3.6 Redirections</A>). -<P> - -<LI> -Bash contains the <SAMP>`<>'</SAMP> redirection operator, allowing a file to be -opened for both reading and writing, and the <SAMP>`&>'</SAMP> redirection -operator, for directing standard output and standard error to the same -file (see section <A HREF="b.html#SEC38">3.6 Redirections</A>). -<P> - -<LI> -Bash includes the <SAMP>`<<<'</SAMP> redirection operator, allowing a string to -be used as the standard input to a command. -<P> - -<LI> -Bash implements the <SAMP>`[n]<&<VAR>word</VAR>'</SAMP> and <SAMP>`[n]>&<VAR>word</VAR>'</SAMP> -redirection operators, which move one file descriptor to another. -<P> - -<LI> -Bash treats a number of filenames specially when they are -used in redirection operators (see section <A HREF="b.html#SEC38">3.6 Redirections</A>). -<P> - -<LI> -Bash can open network connections to arbitrary machines and services -with the redirection operators (see section <A HREF="b.html#SEC38">3.6 Redirections</A>). -<P> - -<LI> -The <CODE>noclobber</CODE> option is available to avoid overwriting existing -files with output redirection (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -The <SAMP>`>|'</SAMP> redirection operator may be used to override <CODE>noclobber</CODE>. -<P> - -<LI> -The Bash <CODE>cd</CODE> and <CODE>pwd</CODE> builtins (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>) -each take <SAMP>`-L'</SAMP> and <SAMP>`-P'</SAMP> options to switch between logical and -physical modes. -<P> - -<LI> -Bash allows a function to override a builtin with the same name, and provides -access to that builtin's functionality within the function via the -<CODE>builtin</CODE> and <CODE>command</CODE> builtins (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<LI> -The <CODE>command</CODE> builtin allows selective disabling of functions -when command lookup is performed (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<LI> -Individual builtins may be enabled or disabled using the <CODE>enable</CODE> -builtin (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<LI> -The Bash <CODE>exec</CODE> builtin takes additional options that allow users -to control the contents of the environment passed to the executed -command, and what the zeroth argument to the command is to be -(see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -<P> - -<LI> -Shell functions may be exported to children via the environment -using <CODE>export -f</CODE> (see section <A HREF="b.html#SEC23">3.3 Shell Functions</A>). -<P> - -<LI> -The Bash <CODE>export</CODE>, <CODE>readonly</CODE>, and <CODE>declare</CODE> builtins can -take a <SAMP>`-f'</SAMP> option to act on shell functions, a <SAMP>`-p'</SAMP> option to -display variables with various attributes set in a format that can be -used as shell input, a <SAMP>`-n'</SAMP> option to remove various variable -attributes, and <SAMP>`name=value'</SAMP> arguments to set variable attributes -and values simultaneously. -<P> - -<LI> -The Bash <CODE>hash</CODE> builtin allows a name to be associated with -an arbitrary filename, even when that filename cannot be found by -searching the <CODE>$PATH</CODE>, using <SAMP>`hash -p'</SAMP> -(see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -<P> - -<LI> -Bash includes a <CODE>help</CODE> builtin for quick reference to shell -facilities (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<LI> -The <CODE>printf</CODE> builtin is available to display formatted output -(see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<LI> -The Bash <CODE>read</CODE> builtin (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>) -will read a line ending in <SAMP>`\'</SAMP> with -the <SAMP>`-r'</SAMP> option, and will use the <CODE>REPLY</CODE> variable as a -default if no non-option arguments are supplied. -The Bash <CODE>read</CODE> builtin -also accepts a prompt string with the <SAMP>`-p'</SAMP> option and will use -Readline to obtain the line when given the <SAMP>`-e'</SAMP> option. -The <CODE>read</CODE> builtin also has additional options to control input: -the <SAMP>`-s'</SAMP> option will turn off echoing of input characters as -they are read, the <SAMP>`-t'</SAMP> option will allow <CODE>read</CODE> to time out -if input does not arrive within a specified number of seconds, the -<SAMP>`-n'</SAMP> option will allow reading only a specified number of -characters rather than a full line, and the <SAMP>`-d'</SAMP> option will read -until a particular character rather than newline. -<P> - -<LI> -The <CODE>return</CODE> builtin may be used to abort execution of scripts -executed with the <CODE>.</CODE> or <CODE>source</CODE> builtins -(see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -<P> - -<LI> -Bash includes the <CODE>shopt</CODE> builtin, for finer control of shell -optional capabilities (see section <A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A>), and allows these options -to be set and unset at shell invocation (see section <A HREF="b.html#SEC67">6.1 Invoking Bash</A>). -<P> - -<LI> -Bash has much more optional behavior controllable with the <CODE>set</CODE> -builtin (see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -<P> - -<LI> -The <SAMP>`-x'</SAMP> (<CODE>xtrace</CODE>) option displays commands other than -simple commands when performing an execution trace -(see section <A HREF="b.html#SEC60">4.3.1 The Set Builtin</A>). -<P> - -<LI> -The <CODE>test</CODE> builtin (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>) -is slightly different, as it implements the POSIX algorithm, -which specifies the behavior based on the number of arguments. -<P> - -<LI> -Bash includes the <CODE>caller</CODE> builtin, which displays the context of -any active subroutine call (a shell function or a script executed with -the <CODE>.</CODE> or <CODE>source</CODE> builtins). This supports the bash -debugger. -<P> - -<LI> -The <CODE>trap</CODE> builtin (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>) allows a -<CODE>DEBUG</CODE> pseudo-signal specification, similar to <CODE>EXIT</CODE>. -Commands specified with a <CODE>DEBUG</CODE> trap are executed before every -simple command, <CODE>for</CODE> command, <CODE>case</CODE> command, -<CODE>select</CODE> command, every arithmetic <CODE>for</CODE> command, and before -the first command executes in a shell function. -The <CODE>DEBUG</CODE> trap is not inherited by shell functions unless the -function has been given the <CODE>trace</CODE> attribute or the -<CODE>functrace</CODE> option has been enabled using the <CODE>shopt</CODE> builtin. -The <CODE>extdebug</CODE> shell option has additional effects on the -<CODE>DEBUG</CODE> trap. -<P> - -The <CODE>trap</CODE> builtin (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>) allows an -<CODE>ERR</CODE> pseudo-signal specification, similar to <CODE>EXIT</CODE> and <CODE>DEBUG</CODE>. -Commands specified with an <CODE>ERR</CODE> trap are executed after a simple -command fails, with a few exceptions. -The <CODE>ERR</CODE> trap is not inherited by shell functions unless the -<CODE>-o errtrace</CODE> option to the <CODE>set</CODE> builtin is enabled. -</P><P> - -The <CODE>trap</CODE> builtin (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>) allows a -<CODE>RETURN</CODE> pseudo-signal specification, similar to -<CODE>EXIT</CODE> and <CODE>DEBUG</CODE>. -Commands specified with an <CODE>RETURN</CODE> trap are executed before -execution resumes after a shell function or a shell script executed with -<CODE>.</CODE> or <CODE>source</CODE> returns. -The <CODE>RETURN</CODE> trap is not inherited by shell functions unless the -function has been given the <CODE>trace</CODE> attribute or the -<CODE>functrace</CODE> option has been enabled using the <CODE>shopt</CODE> builtin. -</P><P> - -<LI> -The Bash <CODE>type</CODE> builtin is more extensive and gives more information -about the names it finds (see section <A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A>). -<P> - -<LI> -The Bash <CODE>umask</CODE> builtin permits a <SAMP>`-p'</SAMP> option to cause -the output to be displayed in the form of a <CODE>umask</CODE> command -that may be reused as input (see section <A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A>). -<P> - -<LI> -Bash implements a <CODE>csh</CODE>-like directory stack, and provides the -<CODE>pushd</CODE>, <CODE>popd</CODE>, and <CODE>dirs</CODE> builtins to manipulate it -(see section <A HREF="b.html#SEC84">6.8 The Directory Stack</A>). -Bash also makes the directory stack visible as the value of the -<CODE>DIRSTACK</CODE> shell variable. -<P> - -<LI> -Bash interprets special backslash-escaped characters in the prompt -strings when interactive (see section <A HREF="b.html#SEC86">6.9 Controlling the Prompt</A>). -<P> - -<LI> -The Bash restricted mode is more useful (see section <A HREF="b.html#SEC87">6.10 The Restricted Shell</A>); -the SVR4.2 shell restricted mode is too limited. -<P> - -<LI> -The <CODE>disown</CODE> builtin can remove a job from the internal shell -job table (see section <A HREF="b.html#SEC91">7.2 Job Control Builtins</A>) or suppress the sending -of <CODE>SIGHUP</CODE> to a job when the shell exits as the result of a -<CODE>SIGHUP</CODE>. -<P> - -<LI> -Bash includes a number of features to support a separate debugger for -shell scripts. -<P> - -<LI> -The SVR4.2 shell has two privilege-related builtins -(<CODE>mldmode</CODE> and <CODE>priv</CODE>) not present in Bash. -<P> - -<LI> -Bash does not have the <CODE>stop</CODE> or <CODE>newgrp</CODE> builtins. -<P> - -<LI> -Bash does not use the <CODE>SHACCT</CODE> variable or perform shell accounting. -<P> - -<LI> -The SVR4.2 <CODE>sh</CODE> uses a <CODE>TIMEOUT</CODE> variable like Bash uses -<CODE>TMOUT</CODE>. -<P> - -</UL> -<P> - -More features unique to Bash may be found in <A HREF="b.html#SEC66">6. Bash Features</A>. -</P><P> - -<HR SIZE="6"> -<A NAME="SEC135"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC134"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC136"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC134"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC134"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC136"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> B.1 Implementation Differences From The SVR4.2 Shell </H2> -<!--docid::SEC135::--> -<P> - -Since Bash is a completely new implementation, it does not suffer from -many of the limitations of the SVR4.2 shell. For instance: -</P><P> - -<UL> - -<LI> -Bash does not fork a subshell when redirecting into or out of -a shell control structure such as an <CODE>if</CODE> or <CODE>while</CODE> -statement. -<P> - -<LI> -Bash does not allow unbalanced quotes. The SVR4.2 shell will silently -insert a needed closing quote at <CODE>EOF</CODE> under certain circumstances. -This can be the cause of some hard-to-find errors. -<P> - -<LI> -The SVR4.2 shell uses a baroque memory management scheme based on -trapping <CODE>SIGSEGV</CODE>. If the shell is started from a process with -<CODE>SIGSEGV</CODE> blocked (e.g., by using the <CODE>system()</CODE> C library -function call), it misbehaves badly. -<P> - -<LI> -In a questionable attempt at security, the SVR4.2 shell, -when invoked without the <SAMP>`-p'</SAMP> option, will alter its real -and effective UID and GID if they are less than some -magic threshold value, commonly 100. -This can lead to unexpected results. -<P> - -<LI> -The SVR4.2 shell does not allow users to trap <CODE>SIGSEGV</CODE>, -<CODE>SIGALRM</CODE>, or <CODE>SIGCHLD</CODE>. -<P> - -<LI> -The SVR4.2 shell does not allow the <CODE>IFS</CODE>, <CODE>MAILCHECK</CODE>, -<CODE>PATH</CODE>, <CODE>PS1</CODE>, or <CODE>PS2</CODE> variables to be unset. -<P> - -<LI> -The SVR4.2 shell treats <SAMP>`^'</SAMP> as the undocumented equivalent of -<SAMP>`|'</SAMP>. -<P> - -<LI> -Bash allows multiple option arguments when it is invoked (<CODE>-x -v</CODE>); -the SVR4.2 shell allows only one option argument (<CODE>-xv</CODE>). In -fact, some versions of the shell dump core if the second argument begins -with a <SAMP>`-'</SAMP>. -<P> - -<LI> -The SVR4.2 shell exits a script if any builtin fails; Bash exits -a script only if one of the POSIX special builtins fails, and -only for certain failures, as enumerated in the POSIX standard. -<P> - -<LI> -The SVR4.2 shell behaves differently when invoked as <CODE>jsh</CODE> -(it turns on job control). -</UL> -<P> - -<A NAME="Copying This Manual"></A> -<HR SIZE="6"> -<A NAME="SEC136"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC135"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC137"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1> C. Copying This Manual </H1> -<!--docid::SEC136::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC137">C.1 GNU Free Documentation License</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">License for copying this manual.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="GNU Free Documentation License"></A> -<HR SIZE="6"> -<A NAME="SEC137"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC136"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC138"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC136"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC136"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> >> </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> C.1 GNU Free Documentation License </H2> -<!--docid::SEC137::--> -<P> - -<A NAME="IDX516"></A> -<center> - Version 1.2, November 2002 -</center> -</P><P> - -<TABLE><tr><td> </td><td class=display><pre style="font-family: serif">Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. -59 Temple Place, Suite 330, Boston, MA 02111-1307, USA - -Everyone is permitted to copy and distribute verbatim copies -of this license document, but changing it is not allowed. -</pre></td></tr></table></P><P> - -<OL> -<LI> -PREAMBLE -<P> - -The purpose of this License is to make a manual, textbook, or other -functional and useful document <EM>free</EM> in the sense of freedom: to -assure everyone the effective freedom to copy and redistribute it, -with or without modifying it, either commercially or noncommercially. -Secondarily, this License preserves for the author and publisher a way -to get credit for their work, while not being considered responsible -for modifications made by others. -</P><P> - -This License is a kind of "copyleft", which means that derivative -works of the document must themselves be free in the same sense. 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Indexes </H1> -<!--docid::SEC139::--> -<P> - -<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC140">D.1 Index of Shell Builtin Commands</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Index of Bash builtin commands.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC141">D.2 Index of Shell Reserved Words</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Index of Bash reserved words.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC142">D.3 Parameter and Variable Index</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Quick reference helps you find the - variable you want.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC143">D.4 Function Index</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Index of bindable Readline functions.</TD></TR> -<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="b.html#SEC144">D.5 Concept Index</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">General index for concepts described in - this manual.</TD></TR> -</TABLE></BLOCKQUOTE> -<P> - -<A NAME="Builtin Index"></A> -<HR SIZE="6"> -<A NAME="SEC140"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC141"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[ >> ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> D.1 Index of Shell Builtin Commands </H2> -<!--docid::SEC140::--> -<table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#bt_." style="text-decoration:none"><b>.</b></A> - -<A HREF="b.html#bt_:" style="text-decoration:none"><b>:</b></A> - -<A HREF="b.html#bt_[" style="text-decoration:none"><b>[</b></A> - -<BR> -<A HREF="b.html#bt_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#bt_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#bt_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#bt_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#bt_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#bt_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#bt_G" style="text-decoration:none"><b>G</b></A> - -<A HREF="b.html#bt_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#bt_J" style="text-decoration:none"><b>J</b></A> - -<A HREF="b.html#bt_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#bt_L" style="text-decoration:none"><b>L</b></A> - -<A HREF="b.html#bt_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#bt_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#bt_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#bt_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#bt_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#bt_W" style="text-decoration:none"><b>W</b></A> - -</td></tr></table><br><P></P> -<TABLE border=0> -<TR><TD></TD><TH ALIGN=LEFT>Index Entry</TH><TH ALIGN=LEFT> Section</TH></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_."></A>.</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX69"><CODE>.</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_:"></A>:</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX68"><CODE>:</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_["></A>[</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX84"><CODE>[</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_A"></A>A</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX89"><CODE>alias</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_B"></A>B</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX281"><CODE>bg</CODE></A></TD><TD valign=top><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX90"><CODE>bind</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX70"><CODE>break</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX91"><CODE>builtin</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_C"></A>C</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX92"><CODE>caller</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX71"><CODE>cd</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX93"><CODE>command</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX510"><CODE>compgen</CODE></A></TD><TD valign=top><A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX511"><CODE>complete</CODE></A></TD><TD valign=top><A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX72"><CODE>continue</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_D"></A>D</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX94"><CODE>declare</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX278"><CODE>dirs</CODE></A></TD><TD valign=top><A HREF="b.html#SEC85">6.8.1 Directory Stack Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX286"><CODE>disown</CODE></A></TD><TD valign=top><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_E"></A>E</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX95"><CODE>echo</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX96"><CODE>enable</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX73"><CODE>eval</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX74"><CODE>exec</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX75"><CODE>exit</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX76"><CODE>export</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_F"></A>F</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX513"><CODE>fc</CODE></A></TD><TD valign=top><A HREF="b.html#SEC119">9.2 Bash History Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX282"><CODE>fg</CODE></A></TD><TD valign=top><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_G"></A>G</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX77"><CODE>getopts</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_H"></A>H</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX78"><CODE>hash</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX97"><CODE>help</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX514"><CODE>history</CODE></A></TD><TD valign=top><A HREF="b.html#SEC119">9.2 Bash History Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_J"></A>J</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX283"><CODE>jobs</CODE></A></TD><TD valign=top><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_K"></A>K</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX284"><CODE>kill</CODE></A></TD><TD valign=top><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_L"></A>L</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX98"><CODE>let</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX99"><CODE>local</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX100"><CODE>logout</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_P"></A>P</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX279"><CODE>popd</CODE></A></TD><TD valign=top><A HREF="b.html#SEC85">6.8.1 Directory Stack Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX101"><CODE>printf</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX280"><CODE>pushd</CODE></A></TD><TD valign=top><A HREF="b.html#SEC85">6.8.1 Directory Stack Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX79"><CODE>pwd</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_R"></A>R</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX102"><CODE>read</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX80"><CODE>readonly</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX81"><CODE>return</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_S"></A>S</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX108"><CODE>set</CODE></A></TD><TD valign=top><A HREF="b.html#SEC60">4.3.1 The Set Builtin</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX82"><CODE>shift</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX109"><CODE>shopt</CODE></A></TD><TD valign=top><A HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX103"><CODE>source</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX287"><CODE>suspend</CODE></A></TD><TD valign=top><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_T"></A>T</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX83"><CODE>test</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX85"><CODE>times</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX86"><CODE>trap</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX104"><CODE>type</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX105"><CODE>typeset</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_U"></A>U</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX106"><CODE>ulimit</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX87"><CODE>umask</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX107"><CODE>unalias</CODE></A></TD><TD valign=top><A HREF="b.html#SEC58">4.2 Bash Builtin Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX88"><CODE>unset</CODE></A></TD><TD valign=top><A HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="bt_W"></A>W</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX285"><CODE>wait</CODE></A></TD><TD valign=top><A HREF="b.html#SEC91">7.2 Job Control Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -</TABLE><P></P><table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#bt_." style="text-decoration:none"><b>.</b></A> - -<A HREF="b.html#bt_:" style="text-decoration:none"><b>:</b></A> - -<A HREF="b.html#bt_[" style="text-decoration:none"><b>[</b></A> - -<BR> -<A HREF="b.html#bt_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#bt_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#bt_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#bt_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#bt_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#bt_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#bt_G" style="text-decoration:none"><b>G</b></A> - -<A HREF="b.html#bt_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#bt_J" style="text-decoration:none"><b>J</b></A> - -<A HREF="b.html#bt_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#bt_L" style="text-decoration:none"><b>L</b></A> - -<A HREF="b.html#bt_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#bt_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#bt_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#bt_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#bt_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#bt_W" style="text-decoration:none"><b>W</b></A> - -</td></tr></table><br><P> - -<A NAME="Reserved Word Index"></A> -<HR SIZE="6"> -<A NAME="SEC141"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC140"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC142"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC142"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[ >> ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> D.2 Index of Shell Reserved Words </H2> -<!--docid::SEC141::--> -<table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#rw_!" style="text-decoration:none"><b>!</b></A> - -<A HREF="b.html#rw_[" style="text-decoration:none"><b>[</b></A> - -<A HREF="b.html#rw_]" style="text-decoration:none"><b>]</b></A> - -<A HREF="b.html#rw_{" style="text-decoration:none"><b>{</b></A> - -<A HREF="b.html#rw_}" style="text-decoration:none"><b>}</b></A> - -<BR> -<A HREF="b.html#rw_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#rw_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#rw_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#rw_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#rw_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#rw_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#rw_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#rw_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#rw_W" style="text-decoration:none"><b>W</b></A> - -</td></tr></table><br><P></P> -<TABLE border=0> -<TR><TD></TD><TH ALIGN=LEFT>Index Entry</TH><TH ALIGN=LEFT> Section</TH></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_!"></A>!</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX25"><CODE>!</CODE></A></TD><TD valign=top><A HREF="b.html#SEC17">3.2.2 Pipelines</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_["></A>[</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX41"><CODE>[[</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_]"></A>]</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX42"><CODE>]]</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_{"></A>{</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX43"><CODE>{</CODE></A></TD><TD valign=top><A HREF="b.html#SEC22">3.2.4.3 Grouping Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_}"></A>}</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX44"><CODE>}</CODE></A></TD><TD valign=top><A HREF="b.html#SEC22">3.2.4.3 Grouping Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_C"></A>C</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX37"><CODE>case</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_D"></A>D</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX28"><CODE>do</CODE></A></TD><TD valign=top><A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX29"><CODE>done</CODE></A></TD><TD valign=top><A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_E"></A>E</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX35"><CODE>elif</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX34"><CODE>else</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX39"><CODE>esac</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_F"></A>F</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX36"><CODE>fi</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX31"><CODE>for</CODE></A></TD><TD valign=top><A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX45"><CODE>function</CODE></A></TD><TD valign=top><A HREF="b.html#SEC23">3.3 Shell Functions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_I"></A>I</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX32"><CODE>if</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX38"><CODE>in</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_S"></A>S</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX40"><CODE>select</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_T"></A>T</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX33"><CODE>then</CODE></A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX24"><CODE>time</CODE></A></TD><TD valign=top><A HREF="b.html#SEC17">3.2.2 Pipelines</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_U"></A>U</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX27"><CODE>until</CODE></A></TD><TD valign=top><A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="rw_W"></A>W</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX30"><CODE>while</CODE></A></TD><TD valign=top><A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -</TABLE><P></P><table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#rw_!" style="text-decoration:none"><b>!</b></A> - -<A HREF="b.html#rw_[" style="text-decoration:none"><b>[</b></A> - -<A HREF="b.html#rw_]" style="text-decoration:none"><b>]</b></A> - -<A HREF="b.html#rw_{" style="text-decoration:none"><b>{</b></A> - -<A HREF="b.html#rw_}" style="text-decoration:none"><b>}</b></A> - -<BR> -<A HREF="b.html#rw_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#rw_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#rw_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#rw_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#rw_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#rw_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#rw_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#rw_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#rw_W" style="text-decoration:none"><b>W</b></A> - -</td></tr></table><br><P> - -<A NAME="Variable Index"></A> -<HR SIZE="6"> -<A NAME="SEC142"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC141"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC143"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC143"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[ >> ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> D.3 Parameter and Variable Index </H2> -<!--docid::SEC142::--> -<table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#vr_!" style="text-decoration:none"><b>!</b></A> - -<A HREF="b.html#vr_#" style="text-decoration:none"><b>#</b></A> - -<A HREF="b.html#vr_$" style="text-decoration:none"><b>$</b></A> - -<A HREF="b.html#vr_*" style="text-decoration:none"><b>*</b></A> - -<A HREF="b.html#vr_-" style="text-decoration:none"><b>-</b></A> - -<A HREF="b.html#vr_0" style="text-decoration:none"><b>0</b></A> - -<A HREF="b.html#vr_?" style="text-decoration:none"><b>?</b></A> - -<A HREF="b.html#vr_@" style="text-decoration:none"><b>@</b></A> - -<A HREF="b.html#vr__" style="text-decoration:none"><b>_</b></A> - -<BR> -<A HREF="b.html#vr_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#vr_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#vr_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#vr_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#vr_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#vr_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#vr_G" style="text-decoration:none"><b>G</b></A> - -<A HREF="b.html#vr_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#vr_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#vr_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#vr_L" style="text-decoration:none"><b>L</b></A> - -<A HREF="b.html#vr_M" style="text-decoration:none"><b>M</b></A> - -<A HREF="b.html#vr_O" style="text-decoration:none"><b>O</b></A> - -<A HREF="b.html#vr_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#vr_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#vr_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#vr_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#vr_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#vr_V" style="text-decoration:none"><b>V</b></A> - -</td></tr></table><br><P></P> -<TABLE border=0> -<TR><TD></TD><TH ALIGN=LEFT>Index Entry</TH><TH ALIGN=LEFT> Section</TH></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_!"></A>!</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX58"><CODE>!</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX59"><CODE>!</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_#"></A>#</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX50"><CODE>#</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX51"><CODE>#</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_$"></A>$</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX56"><CODE>$</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX57"><CODE>$</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_*"></A>*</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX46"><CODE>*</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX47"><CODE>*</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_-"></A>-</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX54"><CODE>-</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX55"><CODE>-</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_0"></A>0</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX60"><CODE>0</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX61"><CODE>0</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_?"></A>?</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX52"><CODE>?</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX53"><CODE>?</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_@"></A>@</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX48"><CODE>@</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX49"><CODE>@</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr__"></A>_</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX62"><CODE>_</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX63"><CODE>_</CODE></A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_A"></A>A</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX288"><CODE>auto_resume</CODE></A></TD><TD valign=top><A HREF="b.html#SEC92">7.3 Job Control Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX289"><CODE>auto_resume</CODE></A></TD><TD valign=top><A HREF="b.html#SEC92">7.3 Job Control Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_B"></A>B</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX130"><CODE>BASH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX131"><CODE>BASH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX134"><CODE>BASH_ARGC</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX135"><CODE>BASH_ARGC</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX136"><CODE>BASH_ARGV</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX137"><CODE>BASH_ARGV</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX138"><CODE>BASH_COMMAND</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX139"><CODE>BASH_COMMAND</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX140"><CODE>BASH_ENV</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX141"><CODE>BASH_ENV</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX142"><CODE>BASH_EXECUTION_STRING</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX143"><CODE>BASH_EXECUTION_STRING</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX144"><CODE>BASH_LINENO</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX145"><CODE>BASH_LINENO</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX146"><CODE>BASH_REMATCH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX147"><CODE>BASH_REMATCH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX148"><CODE>BASH_SOURCE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX149"><CODE>BASH_SOURCE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX150"><CODE>BASH_SUBSHELL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX151"><CODE>BASH_SUBSHELL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX152"><CODE>BASH_VERSINFO</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX153"><CODE>BASH_VERSINFO</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX154"><CODE>BASH_VERSION</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX155"><CODE>BASH_VERSION</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX132"><CODE>BASHPID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX133"><CODE>BASHPID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX295"><CODE>bell-style</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX296"><CODE>bind-tty-special-chars</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_C"></A>C</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX110"><CODE>CDPATH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX111"><CODE>CDPATH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX156"><CODE>COLUMNS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX157"><CODE>COLUMNS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX297"><CODE>comment-begin</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX158"><CODE>COMP_CWORD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX159"><CODE>COMP_CWORD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX166"><CODE>COMP_KEY</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX167"><CODE>COMP_KEY</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX160"><CODE>COMP_LINE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX161"><CODE>COMP_LINE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX162"><CODE>COMP_POINT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX163"><CODE>COMP_POINT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX164"><CODE>COMP_TYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX165"><CODE>COMP_TYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX168"><CODE>COMP_WORDBREAKS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX169"><CODE>COMP_WORDBREAKS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX170"><CODE>COMP_WORDS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX171"><CODE>COMP_WORDS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX298"><CODE>completion-query-items</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX172"><CODE>COMPREPLY</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX173"><CODE>COMPREPLY</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX299"><CODE>convert-meta</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_D"></A>D</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX174"><CODE>DIRSTACK</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX175"><CODE>DIRSTACK</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX300"><CODE>disable-completion</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_E"></A>E</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX301"><CODE>editing-mode</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX176"><CODE>EMACS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX177"><CODE>EMACS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX302"><CODE>enable-keypad</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX178"><CODE>EUID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX179"><CODE>EUID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX303"><CODE>expand-tilde</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_F"></A>F</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX180"><CODE>FCEDIT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX181"><CODE>FCEDIT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX182"><CODE>FIGNORE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX183"><CODE>FIGNORE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX184"><CODE>FUNCNAME</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX185"><CODE>FUNCNAME</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_G"></A>G</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX186"><CODE>GLOBIGNORE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX187"><CODE>GLOBIGNORE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX188"><CODE>GROUPS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX189"><CODE>GROUPS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_H"></A>H</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX190"><CODE>histchars</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX191"><CODE>histchars</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX192"><CODE>HISTCMD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX193"><CODE>HISTCMD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX194"><CODE>HISTCONTROL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX195"><CODE>HISTCONTROL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX196"><CODE>HISTFILE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX197"><CODE>HISTFILE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX198"><CODE>HISTFILESIZE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX199"><CODE>HISTFILESIZE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX200"><CODE>HISTIGNORE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX201"><CODE>HISTIGNORE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX304"><CODE>history-preserve-point</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX202"><CODE>HISTSIZE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX203"><CODE>HISTSIZE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX204"><CODE>HISTTIMEFORMAT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX205"><CODE>HISTTIMEFORMAT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX112"><CODE>HOME</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX113"><CODE>HOME</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX305"><CODE>horizontal-scroll-mode</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX206"><CODE>HOSTFILE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX207"><CODE>HOSTFILE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX208"><CODE>HOSTNAME</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX209"><CODE>HOSTNAME</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX210"><CODE>HOSTTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX211"><CODE>HOSTTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_I"></A>I</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX114"><CODE>IFS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX115"><CODE>IFS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX212"><CODE>IGNOREEOF</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX213"><CODE>IGNOREEOF</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX306"><CODE>input-meta</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX214"><CODE>INPUTRC</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX215"><CODE>INPUTRC</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX308"><CODE>isearch-terminators</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_K"></A>K</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX309"><CODE>keymap</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_L"></A>L</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX216"><CODE>LANG</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX217"><CODE>LANG</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX218"><CODE>LC_ALL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX219"><CODE>LC_ALL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX220"><CODE>LC_COLLATE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX221"><CODE>LC_COLLATE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX222"><CODE>LC_CTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX223"><CODE>LC_CTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX21"><CODE>LC_MESSAGES</CODE></A></TD><TD valign=top><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX224"><CODE>LC_MESSAGES</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX225"><CODE>LC_MESSAGES</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX226"><CODE>LC_NUMERIC</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX227"><CODE>LC_NUMERIC</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX228"><CODE>LINENO</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX229"><CODE>LINENO</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX230"><CODE>LINES</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX231"><CODE>LINES</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_M"></A>M</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX232"><CODE>MACHTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX233"><CODE>MACHTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX116"><CODE>MAIL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX117"><CODE>MAIL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX234"><CODE>MAILCHECK</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX235"><CODE>MAILCHECK</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX118"><CODE>MAILPATH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX119"><CODE>MAILPATH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX310"><CODE>mark-modified-lines</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX311"><CODE>mark-symlinked-directories</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX312"><CODE>match-hidden-files</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX307"><CODE>meta-flag</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_O"></A>O</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX236"><CODE>OLDPWD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX237"><CODE>OLDPWD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX120"><CODE>OPTARG</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX121"><CODE>OPTARG</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX238"><CODE>OPTERR</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX239"><CODE>OPTERR</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX122"><CODE>OPTIND</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX123"><CODE>OPTIND</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX240"><CODE>OSTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX241"><CODE>OSTYPE</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX313"><CODE>output-meta</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_P"></A>P</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX314"><CODE>page-completions</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX124"><CODE>PATH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX125"><CODE>PATH</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX242"><CODE>PIPESTATUS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX243"><CODE>PIPESTATUS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX244"><CODE>POSIXLY_CORRECT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX245"><CODE>POSIXLY_CORRECT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX246"><CODE>PPID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX247"><CODE>PPID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX248"><CODE>PROMPT_COMMAND</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX249"><CODE>PROMPT_COMMAND</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX126"><CODE>PS1</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX127"><CODE>PS1</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX128"><CODE>PS2</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX129"><CODE>PS2</CODE></A></TD><TD valign=top><A HREF="b.html#SEC64">5.1 Bourne Shell Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX250"><CODE>PS3</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX251"><CODE>PS3</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX252"><CODE>PS4</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX253"><CODE>PS4</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX254"><CODE>PWD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX255"><CODE>PWD</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_R"></A>R</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX256"><CODE>RANDOM</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX257"><CODE>RANDOM</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX258"><CODE>REPLY</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX259"><CODE>REPLY</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_S"></A>S</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX260"><CODE>SECONDS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX261"><CODE>SECONDS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX262"><CODE>SHELL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX263"><CODE>SHELL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX264"><CODE>SHELLOPTS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX265"><CODE>SHELLOPTS</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX266"><CODE>SHLVL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX267"><CODE>SHLVL</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX315"><CODE>show-all-if-ambiguous</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX316"><CODE>show-all-if-unmodified</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_T"></A>T</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX22"><CODE>TEXTDOMAIN</CODE></A></TD><TD valign=top><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX23"><CODE>TEXTDOMAINDIR</CODE></A></TD><TD valign=top><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX268"><CODE>TIMEFORMAT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX269"><CODE>TIMEFORMAT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX270"><CODE>TMOUT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX271"><CODE>TMOUT</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX272"><CODE>TMPDIR</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX273"><CODE>TMPDIR</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_U"></A>U</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX274"><CODE>UID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX275"><CODE>UID</CODE></A></TD><TD valign=top><A HREF="b.html#SEC65">5.2 Bash Variables</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="vr_V"></A>V</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX317"><CODE>visible-stats</CODE></A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -</TABLE><P></P><table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#vr_!" style="text-decoration:none"><b>!</b></A> - -<A HREF="b.html#vr_#" style="text-decoration:none"><b>#</b></A> - -<A HREF="b.html#vr_$" style="text-decoration:none"><b>$</b></A> - -<A HREF="b.html#vr_*" style="text-decoration:none"><b>*</b></A> - -<A HREF="b.html#vr_-" style="text-decoration:none"><b>-</b></A> - -<A HREF="b.html#vr_0" style="text-decoration:none"><b>0</b></A> - -<A HREF="b.html#vr_?" style="text-decoration:none"><b>?</b></A> - -<A HREF="b.html#vr_@" style="text-decoration:none"><b>@</b></A> - -<A HREF="b.html#vr__" style="text-decoration:none"><b>_</b></A> - -<BR> -<A HREF="b.html#vr_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#vr_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#vr_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#vr_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#vr_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#vr_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#vr_G" style="text-decoration:none"><b>G</b></A> - -<A HREF="b.html#vr_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#vr_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#vr_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#vr_L" style="text-decoration:none"><b>L</b></A> - -<A HREF="b.html#vr_M" style="text-decoration:none"><b>M</b></A> - -<A HREF="b.html#vr_O" style="text-decoration:none"><b>O</b></A> - -<A HREF="b.html#vr_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#vr_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#vr_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#vr_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#vr_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#vr_V" style="text-decoration:none"><b>V</b></A> - -</td></tr></table><br><P> - -<A NAME="Function Index"></A> -<HR SIZE="6"> -<A NAME="SEC143"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC142"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC144"> > </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC144"> << </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[ >> ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> D.4 Function Index </H2> -<!--docid::SEC143::--> -<table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#fn_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#fn_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#fn_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#fn_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#fn_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#fn_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#fn_G" style="text-decoration:none"><b>G</b></A> - -<A HREF="b.html#fn_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#fn_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#fn_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#fn_M" style="text-decoration:none"><b>M</b></A> - -<A HREF="b.html#fn_N" style="text-decoration:none"><b>N</b></A> - -<A HREF="b.html#fn_O" style="text-decoration:none"><b>O</b></A> - -<A HREF="b.html#fn_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#fn_Q" style="text-decoration:none"><b>Q</b></A> - -<A HREF="b.html#fn_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#fn_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#fn_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#fn_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#fn_Y" style="text-decoration:none"><b>Y</b></A> - -</td></tr></table><br><P></P> -<TABLE border=0> -<TR><TD></TD><TH ALIGN=LEFT>Index Entry</TH><TH ALIGN=LEFT> Section</TH></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_A"></A>A</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX458"><CODE>abort (C-g)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX459"><CODE>abort (C-g)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX334"><CODE>accept-line (Newline or Return)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX335"><CODE>accept-line (Newline or Return)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX500"><CODE>alias-expand-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX501"><CODE>alias-expand-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_B"></A>B</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX324"><CODE>backward-char (C-b)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX325"><CODE>backward-char (C-b)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX362"><CODE>backward-delete-char (Rubout)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX363"><CODE>backward-delete-char (Rubout)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX384"><CODE>backward-kill-line (C-x Rubout)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX385"><CODE>backward-kill-line (C-x Rubout)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX392"><CODE>backward-kill-word (M-<KBD>DEL</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX393"><CODE>backward-kill-word (M-<KBD>DEL</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX328"><CODE>backward-word (M-b)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX329"><CODE>backward-word (M-b)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX340"><CODE>beginning-of-history (M-&#60;)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX341"><CODE>beginning-of-history (M-&#60;)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX318"><CODE>beginning-of-line (C-a)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX319"><CODE>beginning-of-line (C-a)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_C"></A>C</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX454"><CODE>call-last-kbd-macro (C-x e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC112">8.4.7 Keyboard Macros</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX455"><CODE>call-last-kbd-macro (C-x e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC112">8.4.7 Keyboard Macros</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX378"><CODE>capitalize-word (M-c)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX379"><CODE>capitalize-word (M-c)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX474"><CODE>character-search (C-])</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX475"><CODE>character-search (C-])</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX476"><CODE>character-search-backward (M-C-])</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX477"><CODE>character-search-backward (M-C-])</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX330"><CODE>clear-screen (C-l)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX331"><CODE>clear-screen (C-l)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX416"><CODE>complete (<KBD>TAB</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX417"><CODE>complete (<KBD>TAB</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX442"><CODE>complete-command (M-!)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX443"><CODE>complete-command (M-!)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX426"><CODE>complete-filename (M-/)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX427"><CODE>complete-filename (M-/)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX438"><CODE>complete-hostname (M-@)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX439"><CODE>complete-hostname (M-@)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX448"><CODE>complete-into-braces (M-{)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX449"><CODE>complete-into-braces (M-{)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX430"><CODE>complete-username (M-~)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX431"><CODE>complete-username (M-~)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX434"><CODE>complete-variable (M-$)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX435"><CODE>complete-variable (M-$)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX404"><CODE>copy-backward-word ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX405"><CODE>copy-backward-word ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX406"><CODE>copy-forward-word ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX407"><CODE>copy-forward-word ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX402"><CODE>copy-region-as-kill ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX403"><CODE>copy-region-as-kill ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_D"></A>D</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX360"><CODE>delete-char (C-d)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX361"><CODE>delete-char (C-d)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX424"><CODE>delete-char-or-list ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX425"><CODE>delete-char-or-list ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX398"><CODE>delete-horizontal-space ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX399"><CODE>delete-horizontal-space ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX412"><CODE>digit-argument (<KBD>M-0</KBD>, <KBD>M-1</KBD>, <small>...</small> <KBD>M--</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC110">8.4.5 Specifying Numeric Arguments</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX413"><CODE>digit-argument (<KBD>M-0</KBD>, <KBD>M-1</KBD>, <small>...</small> <KBD>M--</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC110">8.4.5 Specifying Numeric Arguments</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX492"><CODE>display-shell-version (C-x C-v)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX493"><CODE>display-shell-version (C-x C-v)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX460"><CODE>do-uppercase-version (M-a, M-b, M-<VAR>x</VAR>, <small>...</small>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX461"><CODE>do-uppercase-version (M-a, M-b, M-<VAR>x</VAR>, <small>...</small>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX376"><CODE>downcase-word (M-l)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX377"><CODE>downcase-word (M-l)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX480"><CODE>dump-functions ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX481"><CODE>dump-functions ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX484"><CODE>dump-macros ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX485"><CODE>dump-macros ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX482"><CODE>dump-variables ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX483"><CODE>dump-variables ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX446"><CODE>dynamic-complete-history (M-<KBD>TAB</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX447"><CODE>dynamic-complete-history (M-<KBD>TAB</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_E"></A>E</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX508"><CODE>edit-and-execute-command (C-xC-e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX509"><CODE>edit-and-execute-command (C-xC-e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX452"><CODE>end-kbd-macro (C-x ))</CODE></A></TD><TD valign=top><A HREF="b.html#SEC112">8.4.7 Keyboard Macros</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX453"><CODE>end-kbd-macro (C-x ))</CODE></A></TD><TD valign=top><A HREF="b.html#SEC112">8.4.7 Keyboard Macros</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX342"><CODE>end-of-history (M-&#62;)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX343"><CODE>end-of-history (M-&#62;)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX320"><CODE>end-of-line (C-e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX321"><CODE>end-of-line (C-e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX472"><CODE>exchange-point-and-mark (C-x C-x)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX473"><CODE>exchange-point-and-mark (C-x C-x)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_F"></A>F</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX364"><CODE>forward-backward-delete-char ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX365"><CODE>forward-backward-delete-char ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX322"><CODE>forward-char (C-f)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX323"><CODE>forward-char (C-f)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX346"><CODE>forward-search-history (C-s)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX347"><CODE>forward-search-history (C-s)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX326"><CODE>forward-word (M-f)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX327"><CODE>forward-word (M-f)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_G"></A>G</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX486"><CODE>glob-complete-word (M-g)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX487"><CODE>glob-complete-word (M-g)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX488"><CODE>glob-expand-word (C-x *)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX489"><CODE>glob-expand-word (C-x *)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX490"><CODE>glob-list-expansions (C-x g)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX491"><CODE>glob-list-expansions (C-x g)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_H"></A>H</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX502"><CODE>history-and-alias-expand-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX503"><CODE>history-and-alias-expand-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX496"><CODE>history-expand-line (M-^)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX497"><CODE>history-expand-line (M-^)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX354"><CODE>history-search-backward ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX355"><CODE>history-search-backward ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX352"><CODE>history-search-forward ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX353"><CODE>history-search-forward ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_I"></A>I</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX478"><CODE>insert-comment (M-#)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX479"><CODE>insert-comment (M-#)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX420"><CODE>insert-completions (M-*)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX421"><CODE>insert-completions (M-*)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX504"><CODE>insert-last-argument (M-. or M-_)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX505"><CODE>insert-last-argument (M-. or M-_)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_K"></A>K</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX382"><CODE>kill-line (C-k)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX383"><CODE>kill-line (C-k)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX400"><CODE>kill-region ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX401"><CODE>kill-region ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX388"><CODE>kill-whole-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX389"><CODE>kill-whole-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX390"><CODE>kill-word (M-d)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX391"><CODE>kill-word (M-d)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_M"></A>M</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX498"><CODE>magic-space ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX499"><CODE>magic-space ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX422"><CODE>menu-complete ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX423"><CODE>menu-complete ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_N"></A>N</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX338"><CODE>next-history (C-n)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX339"><CODE>next-history (C-n)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX350"><CODE>non-incremental-forward-search-history (M-n)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX351"><CODE>non-incremental-forward-search-history (M-n)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX348"><CODE>non-incremental-reverse-search-history (M-p)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX349"><CODE>non-incremental-reverse-search-history (M-p)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_O"></A>O</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX506"><CODE>operate-and-get-next (C-o)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX507"><CODE>operate-and-get-next (C-o)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX380"><CODE>overwrite-mode ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX381"><CODE>overwrite-mode ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_P"></A>P</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX444"><CODE>possible-command-completions (C-x !)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX445"><CODE>possible-command-completions (C-x !)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX418"><CODE>possible-completions (M-?)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX419"><CODE>possible-completions (M-?)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX428"><CODE>possible-filename-completions (C-x /)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX429"><CODE>possible-filename-completions (C-x /)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX440"><CODE>possible-hostname-completions (C-x @)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX441"><CODE>possible-hostname-completions (C-x @)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX432"><CODE>possible-username-completions (C-x ~)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX433"><CODE>possible-username-completions (C-x ~)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX436"><CODE>possible-variable-completions (C-x $)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX437"><CODE>possible-variable-completions (C-x $)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX462"><CODE>prefix-meta (<KBD>ESC</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX463"><CODE>prefix-meta (<KBD>ESC</KBD>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX336"><CODE>previous-history (C-p)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX337"><CODE>previous-history (C-p)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_Q"></A>Q</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX366"><CODE>quoted-insert (C-q or C-v)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX367"><CODE>quoted-insert (C-q or C-v)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_R"></A>R</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX456"><CODE>re-read-init-file (C-x C-r)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX457"><CODE>re-read-init-file (C-x C-r)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX332"><CODE>redraw-current-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX333"><CODE>redraw-current-line ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC106">8.4.1 Commands For Moving</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX344"><CODE>reverse-search-history (C-r)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX345"><CODE>reverse-search-history (C-r)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX466"><CODE>revert-line (M-r)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX467"><CODE>revert-line (M-r)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_S"></A>S</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX368"><CODE>self-insert (a, b, A, 1, !, <small>...</small>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX369"><CODE>self-insert (a, b, A, 1, !, <small>...</small>)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX470"><CODE>set-mark (C-@)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX471"><CODE>set-mark (C-@)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX494"><CODE>shell-expand-line (M-C-e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX495"><CODE>shell-expand-line (M-C-e)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX450"><CODE>start-kbd-macro (C-x ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC112">8.4.7 Keyboard Macros</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX451"><CODE>start-kbd-macro (C-x ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC112">8.4.7 Keyboard Macros</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_T"></A>T</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX468"><CODE>tilde-expand (M-&#38;)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX469"><CODE>tilde-expand (M-&#38;)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX370"><CODE>transpose-chars (C-t)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX371"><CODE>transpose-chars (C-t)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX372"><CODE>transpose-words (M-t)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX373"><CODE>transpose-words (M-t)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_U"></A>U</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX464"><CODE>undo (C-_ or C-x C-u)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX465"><CODE>undo (C-_ or C-x C-u)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX414"><CODE>universal-argument ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC110">8.4.5 Specifying Numeric Arguments</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX415"><CODE>universal-argument ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC110">8.4.5 Specifying Numeric Arguments</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX396"><CODE>unix-filename-rubout ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX397"><CODE>unix-filename-rubout ()</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX386"><CODE>unix-line-discard (C-u)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX387"><CODE>unix-line-discard (C-u)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX394"><CODE>unix-word-rubout (C-w)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX395"><CODE>unix-word-rubout (C-w)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX374"><CODE>upcase-word (M-u)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX375"><CODE>upcase-word (M-u)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="fn_Y"></A>Y</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX408"><CODE>yank (C-y)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX409"><CODE>yank (C-y)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX358"><CODE>yank-last-arg (M-. or M-_)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX359"><CODE>yank-last-arg (M-. or M-_)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX356"><CODE>yank-nth-arg (M-C-y)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX357"><CODE>yank-nth-arg (M-C-y)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX410"><CODE>yank-pop (M-y)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX411"><CODE>yank-pop (M-y)</CODE></A></TD><TD valign=top><A HREF="b.html#SEC109">8.4.4 Killing And Yanking</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -</TABLE><P></P><table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#fn_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#fn_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#fn_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#fn_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#fn_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#fn_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#fn_G" style="text-decoration:none"><b>G</b></A> - -<A HREF="b.html#fn_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#fn_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#fn_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#fn_M" style="text-decoration:none"><b>M</b></A> - -<A HREF="b.html#fn_N" style="text-decoration:none"><b>N</b></A> - -<A HREF="b.html#fn_O" style="text-decoration:none"><b>O</b></A> - -<A HREF="b.html#fn_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#fn_Q" style="text-decoration:none"><b>Q</b></A> - -<A HREF="b.html#fn_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#fn_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#fn_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#fn_U" style="text-decoration:none"><b>U</b></A> - -<A HREF="b.html#fn_Y" style="text-decoration:none"><b>Y</b></A> - -</td></tr></table><br><P> - -<A NAME="Concept Index"></A> -<HR SIZE="6"> -<A NAME="SEC144"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC143"> < </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[ > ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[ << ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139"> Up </A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[ >> ]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H2> D.5 Concept Index </H2> -<!--docid::SEC144::--> -<table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#cp_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#cp_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#cp_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#cp_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#cp_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#cp_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#cp_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#cp_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#cp_J" style="text-decoration:none"><b>J</b></A> - -<A HREF="b.html#cp_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#cp_L" style="text-decoration:none"><b>L</b></A> - -<A HREF="b.html#cp_M" style="text-decoration:none"><b>M</b></A> - -<A HREF="b.html#cp_N" style="text-decoration:none"><b>N</b></A> - -<A HREF="b.html#cp_O" style="text-decoration:none"><b>O</b></A> - -<A HREF="b.html#cp_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#cp_Q" style="text-decoration:none"><b>Q</b></A> - -<A HREF="b.html#cp_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#cp_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#cp_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#cp_V" style="text-decoration:none"><b>V</b></A> - -<A HREF="b.html#cp_W" style="text-decoration:none"><b>W</b></A> - -<A HREF="b.html#cp_Y" style="text-decoration:none"><b>Y</b></A> - -</td></tr></table><br><P></P> -<TABLE border=0> -<TR><TD></TD><TH ALIGN=LEFT>Index Entry</TH><TH ALIGN=LEFT> Section</TH></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_A"></A>A</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC82">alias expansion</A></TD><TD valign=top><A HREF="b.html#SEC82">6.6 Aliases</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC81">arithmetic evaluation</A></TD><TD valign=top><A HREF="b.html#SEC81">6.5 Shell Arithmetic</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC32">arithmetic expansion</A></TD><TD valign=top><A HREF="b.html#SEC32">3.5.5 Arithmetic Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC81">arithmetic, shell</A></TD><TD valign=top><A HREF="b.html#SEC81">6.5 Shell Arithmetic</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC83">arrays</A></TD><TD valign=top><A HREF="b.html#SEC83">6.7 Arrays</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_B"></A>B</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC90">background</A></TD><TD valign=top><A HREF="b.html#SEC90">7.1 Job Control Basics</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC125">Bash configuration</A></TD><TD valign=top><A HREF="b.html#SEC125">10.1 Basic Installation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC125">Bash installation</A></TD><TD valign=top><A HREF="b.html#SEC125">10.1 Basic Installation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC5">Bourne shell</A></TD><TD valign=top><A HREF="b.html#SEC5">3. Basic Shell Features</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC28">brace expansion</A></TD><TD valign=top><A HREF="b.html#SEC28">3.5.1 Brace Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX2">builtin</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_C"></A>C</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC96">command editing</A></TD><TD valign=top><A HREF="b.html#SEC96">8.2.1 Readline Bare Essentials</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC50">command execution</A></TD><TD valign=top><A HREF="b.html#SEC50">3.7.2 Command Search and Execution</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC49">command expansion</A></TD><TD valign=top><A HREF="b.html#SEC49">3.7.1 Simple Command Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC118">command history</A></TD><TD valign=top><A HREF="b.html#SEC118">9.1 Bash History Facilities</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC50">command search</A></TD><TD valign=top><A HREF="b.html#SEC50">3.7.2 Command Search and Execution</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC31">command substitution</A></TD><TD valign=top><A HREF="b.html#SEC31">3.5.4 Command Substitution</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX26">command timing</A></TD><TD valign=top><A HREF="b.html#SEC17">3.2.2 Pipelines</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC19">commands, compound</A></TD><TD valign=top><A HREF="b.html#SEC19">3.2.4 Compound Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC21">commands, conditional</A></TD><TD valign=top><A HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC22">commands, grouping</A></TD><TD valign=top><A HREF="b.html#SEC22">3.2.4.3 Grouping Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC18">commands, lists</A></TD><TD valign=top><A HREF="b.html#SEC18">3.2.3 Lists of Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC20">commands, looping</A></TD><TD valign=top><A HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC17">commands, pipelines</A></TD><TD valign=top><A HREF="b.html#SEC17">3.2.2 Pipelines</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC15">commands, shell</A></TD><TD valign=top><A HREF="b.html#SEC15">3.2 Shell Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC16">commands, simple</A></TD><TD valign=top><A HREF="b.html#SEC16">3.2.1 Simple Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC14">comments, shell</A></TD><TD valign=top><A HREF="b.html#SEC14">3.1.3 Comments</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC116">completion builtins</A></TD><TD valign=top><A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC125">configuration</A></TD><TD valign=top><A HREF="b.html#SEC125">10.1 Basic Installation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX3">control operator</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_D"></A>D</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC84">directory stack</A></TD><TD valign=top><A HREF="b.html#SEC84">6.8 The Directory Stack</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_E"></A>E</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC96">editing command lines</A></TD><TD valign=top><A HREF="b.html#SEC96">8.2.1 Readline Bare Essentials</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC52">environment</A></TD><TD valign=top><A HREF="b.html#SEC52">3.7.4 Environment</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC81">evaluation, arithmetic</A></TD><TD valign=top><A HREF="b.html#SEC81">6.5 Shell Arithmetic</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC121">event designators</A></TD><TD valign=top><A HREF="b.html#SEC121">9.3.1 Event Designators</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC51">execution environment</A></TD><TD valign=top><A HREF="b.html#SEC51">3.7.3 Command Execution Environment</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX4">exit status</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC53">exit status</A></TD><TD valign=top><A HREF="b.html#SEC53">3.7.5 Exit Status</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC27">expansion</A></TD><TD valign=top><A HREF="b.html#SEC27">3.5 Shell Expansions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC32">expansion, arithmetic</A></TD><TD valign=top><A HREF="b.html#SEC32">3.5.5 Arithmetic Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC28">expansion, brace</A></TD><TD valign=top><A HREF="b.html#SEC28">3.5.1 Brace Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX64">expansion, filename</A></TD><TD valign=top><A HREF="b.html#SEC35">3.5.8 Filename Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC30">expansion, parameter</A></TD><TD valign=top><A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX65">expansion, pathname</A></TD><TD valign=top><A HREF="b.html#SEC35">3.5.8 Filename Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC29">expansion, tilde</A></TD><TD valign=top><A HREF="b.html#SEC29">3.5.2 Tilde Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC81">expressions, arithmetic</A></TD><TD valign=top><A HREF="b.html#SEC81">6.5 Shell Arithmetic</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC80">expressions, conditional</A></TD><TD valign=top><A HREF="b.html#SEC80">6.4 Bash Conditional Expressions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_F"></A>F</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX516">FDL, GNU Free Documentation License</A></TD><TD valign=top><A HREF="b.html#SEC137">C.1 GNU Free Documentation License</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX5">field</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX6">filename</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX66">filename expansion</A></TD><TD valign=top><A HREF="b.html#SEC35">3.5.8 Filename Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC90">foreground</A></TD><TD valign=top><A HREF="b.html#SEC90">7.1 Job Control Basics</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC23">functions, shell</A></TD><TD valign=top><A HREF="b.html#SEC23">3.3 Shell Functions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_H"></A>H</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC119">history builtins</A></TD><TD valign=top><A HREF="b.html#SEC119">9.2 Bash History Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX515">history events</A></TD><TD valign=top><A HREF="b.html#SEC121">9.3.1 Event Designators</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC120">history expansion</A></TD><TD valign=top><A HREF="b.html#SEC120">9.3 History Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC118">history list</A></TD><TD valign=top><A HREF="b.html#SEC118">9.1 Bash History Facilities</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX512">History, how to use</A></TD><TD valign=top><A HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_I"></A>I</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX11">identifier</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC101">initialization file, readline</A></TD><TD valign=top><A HREF="b.html#SEC101">8.3 Readline Init File</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC125">installation</A></TD><TD valign=top><A HREF="b.html#SEC125">10.1 Basic Installation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC95">interaction, readline</A></TD><TD valign=top><A HREF="b.html#SEC95">8.2 Readline Interaction</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX277">interactive shell</A></TD><TD valign=top><A HREF="b.html#SEC67">6.1 Invoking Bash</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC76">interactive shell</A></TD><TD valign=top><A HREF="b.html#SEC76">6.3 Interactive Shells</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC13">internationalization</A></TD><TD valign=top><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_J"></A>J</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX7">job</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX8">job control</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC90">job control</A></TD><TD valign=top><A HREF="b.html#SEC90">7.1 Job Control Basics</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_K"></A>K</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX293">kill ring</A></TD><TD valign=top><A HREF="b.html#SEC98">8.2.3 Readline Killing Commands</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX291">killing text</A></TD><TD valign=top><A HREF="b.html#SEC98">8.2.3 Readline Killing Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_L"></A>L</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC13">localization</A></TD><TD valign=top><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX276">login shell</A></TD><TD valign=top><A HREF="b.html#SEC67">6.1 Invoking Bash</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_M"></A>M</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC36">matching, pattern</A></TD><TD valign=top><A HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX9">metacharacter</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_N"></A>N</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX10">name</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC13">native languages</A></TD><TD valign=top><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC96">notation, readline</A></TD><TD valign=top><A HREF="b.html#SEC96">8.2.1 Readline Bare Essentials</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_O"></A>O</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX12">operator, shell</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_P"></A>P</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC30">parameter expansion</A></TD><TD valign=top><A HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC24">parameters</A></TD><TD valign=top><A HREF="b.html#SEC24">3.4 Shell Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC25">parameters, positional</A></TD><TD valign=top><A HREF="b.html#SEC25">3.4.1 Positional Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC26">parameters, special</A></TD><TD valign=top><A HREF="b.html#SEC26">3.4.2 Special Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX67">pathname expansion</A></TD><TD valign=top><A HREF="b.html#SEC35">3.5.8 Filename Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC36">pattern matching</A></TD><TD valign=top><A HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC17">pipeline</A></TD><TD valign=top><A HREF="b.html#SEC17">3.2.2 Pipelines</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX1">POSIX</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC88">POSIX Mode</A></TD><TD valign=top><A HREF="b.html#SEC88">6.11 Bash POSIX Mode</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX13">process group</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX14">process group ID</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC33">process substitution</A></TD><TD valign=top><A HREF="b.html#SEC33">3.5.6 Process Substitution</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC115">programmable completion</A></TD><TD valign=top><A HREF="b.html#SEC115">8.6 Programmable Completion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC86">prompting</A></TD><TD valign=top><A HREF="b.html#SEC86">6.9 Controlling the Prompt</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_Q"></A>Q</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC8">quoting</A></TD><TD valign=top><A HREF="b.html#SEC8">3.1.2 Quoting</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC12">quoting, ANSI</A></TD><TD valign=top><A HREF="b.html#SEC12">3.1.2.4 ANSI-C Quoting</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_R"></A>R</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX290">Readline, how to use</A></TD><TD valign=top><A HREF="b.html#SEC92">7.3 Job Control Variables</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC38">redirection</A></TD><TD valign=top><A HREF="b.html#SEC38">3.6 Redirections</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX15">reserved word</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC87">restricted shell</A></TD><TD valign=top><A HREF="b.html#SEC87">6.10 The Restricted Shell</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX16">return status</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_S"></A>S</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC81">shell arithmetic</A></TD><TD valign=top><A HREF="b.html#SEC81">6.5 Shell Arithmetic</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC23">shell function</A></TD><TD valign=top><A HREF="b.html#SEC23">3.3 Shell Functions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC55">shell script</A></TD><TD valign=top><A HREF="b.html#SEC55">3.8 Shell Scripts</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC24">shell variable</A></TD><TD valign=top><A HREF="b.html#SEC24">3.4 Shell Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC76">shell, interactive</A></TD><TD valign=top><A HREF="b.html#SEC76">6.3 Interactive Shells</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX17">signal</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC54">signal handling</A></TD><TD valign=top><A HREF="b.html#SEC54">3.7.6 Signals</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX18">special builtin</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC62">special builtin</A></TD><TD valign=top><A HREF="b.html#SEC62">4.4 Special Builtins</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC68">startup files</A></TD><TD valign=top><A HREF="b.html#SEC68">6.2 Bash Startup Files</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC90">suspending jobs</A></TD><TD valign=top><A HREF="b.html#SEC90">7.1 Job Control Basics</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_T"></A>T</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC29">tilde expansion</A></TD><TD valign=top><A HREF="b.html#SEC29">3.5.2 Tilde Expansion</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX19">token</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC13">translation, native languages</A></TD><TD valign=top><A HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_V"></A>V</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC24">variable, shell</A></TD><TD valign=top><A HREF="b.html#SEC24">3.4 Shell Parameters</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX294">variables, readline</A></TD><TD valign=top><A HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_W"></A>W</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX20">word</A></TD><TD valign=top><A HREF="b.html#SEC4">2. Definitions</A></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#SEC34">word splitting</A></TD><TD valign=top><A HREF="b.html#SEC34">3.5.7 Word Splitting</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -<TR><TH><A NAME="cp_Y"></A>Y</TH><TD></TD><TD></TD></TR> -<TR><TD></TD><TD valign=top><A HREF="b.html#IDX292">yanking text</A></TD><TD valign=top><A HREF="b.html#SEC98">8.2.3 Readline Killing Commands</A></TD></TR> -<TR><TD COLSPAN=3> <HR></TD></TR> -</TABLE><P></P><table><tr><th valign=top>Jump to: </th><td><A HREF="b.html#cp_A" style="text-decoration:none"><b>A</b></A> - -<A HREF="b.html#cp_B" style="text-decoration:none"><b>B</b></A> - -<A HREF="b.html#cp_C" style="text-decoration:none"><b>C</b></A> - -<A HREF="b.html#cp_D" style="text-decoration:none"><b>D</b></A> - -<A HREF="b.html#cp_E" style="text-decoration:none"><b>E</b></A> - -<A HREF="b.html#cp_F" style="text-decoration:none"><b>F</b></A> - -<A HREF="b.html#cp_H" style="text-decoration:none"><b>H</b></A> - -<A HREF="b.html#cp_I" style="text-decoration:none"><b>I</b></A> - -<A HREF="b.html#cp_J" style="text-decoration:none"><b>J</b></A> - -<A HREF="b.html#cp_K" style="text-decoration:none"><b>K</b></A> - -<A HREF="b.html#cp_L" style="text-decoration:none"><b>L</b></A> - -<A HREF="b.html#cp_M" style="text-decoration:none"><b>M</b></A> - -<A HREF="b.html#cp_N" style="text-decoration:none"><b>N</b></A> - -<A HREF="b.html#cp_O" style="text-decoration:none"><b>O</b></A> - -<A HREF="b.html#cp_P" style="text-decoration:none"><b>P</b></A> - -<A HREF="b.html#cp_Q" style="text-decoration:none"><b>Q</b></A> - -<A HREF="b.html#cp_R" style="text-decoration:none"><b>R</b></A> - -<A HREF="b.html#cp_S" style="text-decoration:none"><b>S</b></A> - -<A HREF="b.html#cp_T" style="text-decoration:none"><b>T</b></A> - -<A HREF="b.html#cp_V" style="text-decoration:none"><b>V</b></A> - -<A HREF="b.html#cp_W" style="text-decoration:none"><b>W</b></A> - -<A HREF="b.html#cp_Y" style="text-decoration:none"><b>Y</b></A> - -</td></tr></table><br><P> - -<HR SIZE="6"> -<A NAME="SEC_Contents"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1>Table of Contents</H1> -<UL> -<A NAME="TOC1" HREF="b.html#SEC1">1. Introduction</A> -<BR> -<UL> -<A NAME="TOC2" HREF="b.html#SEC2">1.1 What is Bash?</A> -<BR> -<A NAME="TOC3" HREF="b.html#SEC3">1.2 What is a shell?</A> -<BR> -</UL> -<A NAME="TOC4" HREF="b.html#SEC4">2. Definitions</A> -<BR> -<A NAME="TOC5" HREF="b.html#SEC5">3. Basic Shell Features</A> -<BR> -<UL> -<A NAME="TOC6" HREF="b.html#SEC6">3.1 Shell Syntax</A> -<BR> -<UL> -<A NAME="TOC7" HREF="b.html#SEC7">3.1.1 Shell Operation</A> -<BR> -<A NAME="TOC8" HREF="b.html#SEC8">3.1.2 Quoting</A> -<BR> -<UL> -<A NAME="TOC9" HREF="b.html#SEC9">3.1.2.1 Escape Character</A> -<BR> -<A NAME="TOC10" HREF="b.html#SEC10">3.1.2.2 Single Quotes</A> -<BR> -<A NAME="TOC11" HREF="b.html#SEC11">3.1.2.3 Double Quotes</A> -<BR> -<A NAME="TOC12" HREF="b.html#SEC12">3.1.2.4 ANSI-C Quoting</A> -<BR> -<A NAME="TOC13" HREF="b.html#SEC13">3.1.2.5 Locale-Specific Translation</A> -<BR> -</UL> -<A NAME="TOC14" HREF="b.html#SEC14">3.1.3 Comments</A> -<BR> -</UL> -<A NAME="TOC15" HREF="b.html#SEC15">3.2 Shell Commands</A> -<BR> -<UL> -<A NAME="TOC16" HREF="b.html#SEC16">3.2.1 Simple Commands</A> -<BR> -<A NAME="TOC17" HREF="b.html#SEC17">3.2.2 Pipelines</A> -<BR> -<A NAME="TOC18" HREF="b.html#SEC18">3.2.3 Lists of Commands</A> -<BR> -<A NAME="TOC19" HREF="b.html#SEC19">3.2.4 Compound Commands</A> -<BR> -<UL> -<A NAME="TOC20" HREF="b.html#SEC20">3.2.4.1 Looping Constructs</A> -<BR> -<A NAME="TOC21" HREF="b.html#SEC21">3.2.4.2 Conditional Constructs</A> -<BR> -<A NAME="TOC22" HREF="b.html#SEC22">3.2.4.3 Grouping Commands</A> -<BR> -</UL> -</UL> -<A NAME="TOC23" HREF="b.html#SEC23">3.3 Shell Functions</A> -<BR> -<A NAME="TOC24" HREF="b.html#SEC24">3.4 Shell Parameters</A> -<BR> -<UL> -<A NAME="TOC25" HREF="b.html#SEC25">3.4.1 Positional Parameters</A> -<BR> -<A NAME="TOC26" HREF="b.html#SEC26">3.4.2 Special Parameters</A> -<BR> -</UL> -<A NAME="TOC27" HREF="b.html#SEC27">3.5 Shell Expansions</A> -<BR> -<UL> -<A NAME="TOC28" HREF="b.html#SEC28">3.5.1 Brace Expansion</A> -<BR> -<A NAME="TOC29" HREF="b.html#SEC29">3.5.2 Tilde Expansion</A> -<BR> -<A NAME="TOC30" HREF="b.html#SEC30">3.5.3 Shell Parameter Expansion</A> -<BR> -<A NAME="TOC31" HREF="b.html#SEC31">3.5.4 Command Substitution</A> -<BR> -<A NAME="TOC32" HREF="b.html#SEC32">3.5.5 Arithmetic Expansion</A> -<BR> -<A NAME="TOC33" HREF="b.html#SEC33">3.5.6 Process Substitution</A> -<BR> -<A NAME="TOC34" HREF="b.html#SEC34">3.5.7 Word Splitting</A> -<BR> -<A NAME="TOC35" HREF="b.html#SEC35">3.5.8 Filename Expansion</A> -<BR> -<UL> -<A NAME="TOC36" HREF="b.html#SEC36">3.5.8.1 Pattern Matching</A> -<BR> -</UL> -<A NAME="TOC37" HREF="b.html#SEC37">3.5.9 Quote Removal</A> -<BR> -</UL> -<A NAME="TOC38" HREF="b.html#SEC38">3.6 Redirections</A> -<BR> -<UL> -<A NAME="TOC39" HREF="b.html#SEC39">3.6.1 Redirecting Input</A> -<BR> -<A NAME="TOC40" HREF="b.html#SEC40">3.6.2 Redirecting Output</A> -<BR> -<A NAME="TOC41" HREF="b.html#SEC41">3.6.3 Appending Redirected Output</A> -<BR> -<A NAME="TOC42" HREF="b.html#SEC42">3.6.4 Redirecting Standard Output and Standard Error</A> -<BR> -<A NAME="TOC43" HREF="b.html#SEC43">3.6.5 Here Documents</A> -<BR> -<A NAME="TOC44" HREF="b.html#SEC44">3.6.6 Here Strings</A> -<BR> -<A NAME="TOC45" HREF="b.html#SEC45">3.6.7 Duplicating File Descriptors</A> -<BR> -<A NAME="TOC46" HREF="b.html#SEC46">3.6.8 Moving File Descriptors</A> -<BR> -<A NAME="TOC47" HREF="b.html#SEC47">3.6.9 Opening File Descriptors for Reading and Writing</A> -<BR> -</UL> -<A NAME="TOC48" HREF="b.html#SEC48">3.7 Executing Commands</A> -<BR> -<UL> -<A NAME="TOC49" HREF="b.html#SEC49">3.7.1 Simple Command Expansion</A> -<BR> -<A NAME="TOC50" HREF="b.html#SEC50">3.7.2 Command Search and Execution</A> -<BR> -<A NAME="TOC51" HREF="b.html#SEC51">3.7.3 Command Execution Environment</A> -<BR> -<A NAME="TOC52" HREF="b.html#SEC52">3.7.4 Environment</A> -<BR> -<A NAME="TOC53" HREF="b.html#SEC53">3.7.5 Exit Status</A> -<BR> -<A NAME="TOC54" HREF="b.html#SEC54">3.7.6 Signals</A> -<BR> -</UL> -<A NAME="TOC55" HREF="b.html#SEC55">3.8 Shell Scripts</A> -<BR> -</UL> -<A NAME="TOC56" HREF="b.html#SEC56">4. Shell Builtin Commands</A> -<BR> -<UL> -<A NAME="TOC57" HREF="b.html#SEC57">4.1 Bourne Shell Builtins</A> -<BR> -<A NAME="TOC58" HREF="b.html#SEC58">4.2 Bash Builtin Commands</A> -<BR> -<A NAME="TOC59" HREF="b.html#SEC59">4.3 Modifying Shell Behavior</A> -<BR> -<UL> -<A NAME="TOC60" HREF="b.html#SEC60">4.3.1 The Set Builtin</A> -<BR> -<A NAME="TOC61" HREF="b.html#SEC61">4.3.2 The Shopt Builtin</A> -<BR> -</UL> -<A NAME="TOC62" HREF="b.html#SEC62">4.4 Special Builtins</A> -<BR> -</UL> -<A NAME="TOC63" HREF="b.html#SEC63">5. Shell Variables</A> -<BR> -<UL> -<A NAME="TOC64" HREF="b.html#SEC64">5.1 Bourne Shell Variables</A> -<BR> -<A NAME="TOC65" HREF="b.html#SEC65">5.2 Bash Variables</A> -<BR> -</UL> -<A NAME="TOC66" HREF="b.html#SEC66">6. Bash Features</A> -<BR> -<UL> -<A NAME="TOC67" HREF="b.html#SEC67">6.1 Invoking Bash</A> -<BR> -<A NAME="TOC68" HREF="b.html#SEC68">6.2 Bash Startup Files</A> -<BR> -<A NAME="TOC76" HREF="b.html#SEC76">6.3 Interactive Shells</A> -<BR> -<UL> -<A NAME="TOC77" HREF="b.html#SEC77">6.3.1 What is an Interactive Shell?</A> -<BR> -<A NAME="TOC78" HREF="b.html#SEC78">6.3.2 Is this Shell Interactive?</A> -<BR> -<A NAME="TOC79" HREF="b.html#SEC79">6.3.3 Interactive Shell Behavior</A> -<BR> -</UL> -<A NAME="TOC80" HREF="b.html#SEC80">6.4 Bash Conditional Expressions</A> -<BR> -<A NAME="TOC81" HREF="b.html#SEC81">6.5 Shell Arithmetic</A> -<BR> -<A NAME="TOC82" HREF="b.html#SEC82">6.6 Aliases</A> -<BR> -<A NAME="TOC83" HREF="b.html#SEC83">6.7 Arrays</A> -<BR> -<A NAME="TOC84" HREF="b.html#SEC84">6.8 The Directory Stack</A> -<BR> -<UL> -<A NAME="TOC85" HREF="b.html#SEC85">6.8.1 Directory Stack Builtins</A> -<BR> -</UL> -<A NAME="TOC86" HREF="b.html#SEC86">6.9 Controlling the Prompt</A> -<BR> -<A NAME="TOC87" HREF="b.html#SEC87">6.10 The Restricted Shell</A> -<BR> -<A NAME="TOC88" HREF="b.html#SEC88">6.11 Bash POSIX Mode</A> -<BR> -</UL> -<A NAME="TOC89" HREF="b.html#SEC89">7. Job Control</A> -<BR> -<UL> -<A NAME="TOC90" HREF="b.html#SEC90">7.1 Job Control Basics</A> -<BR> -<A NAME="TOC91" HREF="b.html#SEC91">7.2 Job Control Builtins</A> -<BR> -<A NAME="TOC92" HREF="b.html#SEC92">7.3 Job Control Variables</A> -<BR> -</UL> -<A NAME="TOC93" HREF="b.html#SEC93">8. Command Line Editing</A> -<BR> -<UL> -<A NAME="TOC94" HREF="b.html#SEC94">8.1 Introduction to Line Editing</A> -<BR> -<A NAME="TOC95" HREF="b.html#SEC95">8.2 Readline Interaction</A> -<BR> -<UL> -<A NAME="TOC96" HREF="b.html#SEC96">8.2.1 Readline Bare Essentials</A> -<BR> -<A NAME="TOC97" HREF="b.html#SEC97">8.2.2 Readline Movement Commands</A> -<BR> -<A NAME="TOC98" HREF="b.html#SEC98">8.2.3 Readline Killing Commands</A> -<BR> -<A NAME="TOC99" HREF="b.html#SEC99">8.2.4 Readline Arguments</A> -<BR> -<A NAME="TOC100" HREF="b.html#SEC100">8.2.5 Searching for Commands in the History</A> -<BR> -</UL> -<A NAME="TOC101" HREF="b.html#SEC101">8.3 Readline Init File</A> -<BR> -<UL> -<A NAME="TOC102" HREF="b.html#SEC102">8.3.1 Readline Init File Syntax</A> -<BR> -<A NAME="TOC103" HREF="b.html#SEC103">8.3.2 Conditional Init Constructs</A> -<BR> -<A NAME="TOC104" HREF="b.html#SEC104">8.3.3 Sample Init File</A> -<BR> -</UL> -<A NAME="TOC105" HREF="b.html#SEC105">8.4 Bindable Readline Commands</A> -<BR> -<UL> -<A NAME="TOC106" HREF="b.html#SEC106">8.4.1 Commands For Moving</A> -<BR> -<A NAME="TOC107" HREF="b.html#SEC107">8.4.2 Commands For Manipulating The History</A> -<BR> -<A NAME="TOC108" HREF="b.html#SEC108">8.4.3 Commands For Changing Text</A> -<BR> -<A NAME="TOC109" HREF="b.html#SEC109">8.4.4 Killing And Yanking</A> -<BR> -<A NAME="TOC110" HREF="b.html#SEC110">8.4.5 Specifying Numeric Arguments</A> -<BR> -<A NAME="TOC111" HREF="b.html#SEC111">8.4.6 Letting Readline Type For You</A> -<BR> -<A NAME="TOC112" HREF="b.html#SEC112">8.4.7 Keyboard Macros</A> -<BR> -<A NAME="TOC113" HREF="b.html#SEC113">8.4.8 Some Miscellaneous Commands</A> -<BR> -</UL> -<A NAME="TOC114" HREF="b.html#SEC114">8.5 Readline vi Mode</A> -<BR> -<A NAME="TOC115" HREF="b.html#SEC115">8.6 Programmable Completion</A> -<BR> -<A NAME="TOC116" HREF="b.html#SEC116">8.7 Programmable Completion Builtins</A> -<BR> -</UL> -<A NAME="TOC117" HREF="b.html#SEC117">9. Using History Interactively</A> -<BR> -<UL> -<A NAME="TOC118" HREF="b.html#SEC118">9.1 Bash History Facilities</A> -<BR> -<A NAME="TOC119" HREF="b.html#SEC119">9.2 Bash History Builtins</A> -<BR> -<A NAME="TOC120" HREF="b.html#SEC120">9.3 History Expansion</A> -<BR> -<UL> -<A NAME="TOC121" HREF="b.html#SEC121">9.3.1 Event Designators</A> -<BR> -<A NAME="TOC122" HREF="b.html#SEC122">9.3.2 Word Designators</A> -<BR> -<A NAME="TOC123" HREF="b.html#SEC123">9.3.3 Modifiers</A> -<BR> -</UL> -</UL> -<A NAME="TOC124" HREF="b.html#SEC124">10. Installing Bash</A> -<BR> -<UL> -<A NAME="TOC125" HREF="b.html#SEC125">10.1 Basic Installation</A> -<BR> -<A NAME="TOC126" HREF="b.html#SEC126">10.2 Compilers and Options</A> -<BR> -<A NAME="TOC127" HREF="b.html#SEC127">10.3 Compiling For Multiple Architectures</A> -<BR> -<A NAME="TOC128" HREF="b.html#SEC128">10.4 Installation Names</A> -<BR> -<A NAME="TOC129" HREF="b.html#SEC129">10.5 Specifying the System Type</A> -<BR> -<A NAME="TOC130" HREF="b.html#SEC130">10.6 Sharing Defaults</A> -<BR> -<A NAME="TOC131" HREF="b.html#SEC131">10.7 Operation Controls</A> -<BR> -<A NAME="TOC132" HREF="b.html#SEC132">10.8 Optional Features</A> -<BR> -</UL> -<A NAME="TOC133" HREF="b.html#SEC133">A. Reporting Bugs</A> -<BR> -<A NAME="TOC134" HREF="b.html#SEC134">B. Major Differences From The Bourne Shell</A> -<BR> -<UL> -<A NAME="TOC135" HREF="b.html#SEC135">B.1 Implementation Differences From The SVR4.2 Shell</A> -<BR> -</UL> -<A NAME="TOC136" HREF="b.html#SEC136">C. Copying This Manual</A> -<BR> -<UL> -<A NAME="TOC137" HREF="b.html#SEC137">C.1 GNU Free Documentation License</A> -<BR> -<UL> -<A NAME="TOC138" HREF="b.html#SEC138">C.1.1 ADDENDUM: How to use this License for your documents</A> -<BR> -</UL> -</UL> -<A NAME="TOC139" HREF="b.html#SEC139">D. Indexes</A> -<BR> -<UL> -<A NAME="TOC140" HREF="b.html#SEC140">D.1 Index of Shell Builtin Commands</A> -<BR> -<A NAME="TOC141" HREF="b.html#SEC141">D.2 Index of Shell Reserved Words</A> -<BR> -<A NAME="TOC142" HREF="b.html#SEC142">D.3 Parameter and Variable Index</A> -<BR> -<A NAME="TOC143" HREF="b.html#SEC143">D.4 Function Index</A> -<BR> -<A NAME="TOC144" HREF="b.html#SEC144">D.5 Concept Index</A> -<BR> -</UL> -</UL> -<HR SIZE=1> -<A NAME="SEC_OVERVIEW"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1>Short Table of Contents</H1> -<BLOCKQUOTE> -<A NAME="TOC1" HREF="b.html#SEC1">1. Introduction</A> -<BR> -<A NAME="TOC4" HREF="b.html#SEC4">2. Definitions</A> -<BR> -<A NAME="TOC5" HREF="b.html#SEC5">3. Basic Shell Features</A> -<BR> -<A NAME="TOC56" HREF="b.html#SEC56">4. Shell Builtin Commands</A> -<BR> -<A NAME="TOC63" HREF="b.html#SEC63">5. Shell Variables</A> -<BR> -<A NAME="TOC66" HREF="b.html#SEC66">6. Bash Features</A> -<BR> -<A NAME="TOC89" HREF="b.html#SEC89">7. Job Control</A> -<BR> -<A NAME="TOC93" HREF="b.html#SEC93">8. Command Line Editing</A> -<BR> -<A NAME="TOC117" HREF="b.html#SEC117">9. Using History Interactively</A> -<BR> -<A NAME="TOC124" HREF="b.html#SEC124">10. Installing Bash</A> -<BR> -<A NAME="TOC133" HREF="b.html#SEC133">A. Reporting Bugs</A> -<BR> -<A NAME="TOC134" HREF="b.html#SEC134">B. Major Differences From The Bourne Shell</A> -<BR> -<A NAME="TOC136" HREF="b.html#SEC136">C. Copying This Manual</A> -<BR> -<A NAME="TOC139" HREF="b.html#SEC139">D. Indexes</A> -<BR> - -</BLOCKQUOTE> -<HR SIZE=1> -<A NAME="SEC_About"></A> -<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0> -<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Top">Top</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_Contents">Contents</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC139">Index</A>]</TD> -<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="b.html#SEC_About"> ? </A>]</TD> -</TR></TABLE> -<H1>About this document</H1> -This document was generated by <I>Chet Ramey</I> on <I>January, 11 2007</I> -using <A HREF="http://www.mathematik.uni-kl.de/~obachman/Texi2html -"><I>texi2html</I></A> -<P></P> -The buttons in the navigation panels have the following meaning: -<P></P> -<table border = "1"> -<TR> -<TH> Button </TH> -<TH> Name </TH> -<TH> Go to </TH> -<TH> From 1.2.3 go to</TH> -</TR> -<TR> -<TD ALIGN="CENTER"> - [ < ] </TD> -<TD ALIGN="CENTER"> -Back -</TD> -<TD> -previous section in reading order -</TD> -<TD> -1.2.2 -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [ > ] </TD> -<TD ALIGN="CENTER"> -Forward -</TD> -<TD> -next section in reading order -</TD> -<TD> -1.2.4 -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [ << ] </TD> -<TD ALIGN="CENTER"> -FastBack -</TD> -<TD> -previous or up-and-previous section -</TD> -<TD> -1.1 -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [ Up ] </TD> -<TD ALIGN="CENTER"> -Up -</TD> -<TD> -up section -</TD> -<TD> -1.2 -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [ >> ] </TD> -<TD ALIGN="CENTER"> -FastForward -</TD> -<TD> -next or up-and-next section -</TD> -<TD> -1.3 -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [Top] </TD> -<TD ALIGN="CENTER"> -Top -</TD> -<TD> -cover (top) of document -</TD> -<TD> - -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [Contents] </TD> -<TD ALIGN="CENTER"> -Contents -</TD> -<TD> -table of contents -</TD> -<TD> - -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [Index] </TD> -<TD ALIGN="CENTER"> -Index -</TD> -<TD> -concept index -</TD> -<TD> - -</TD> -</TR> -<TR> -<TD ALIGN="CENTER"> - [ ? ] </TD> -<TD ALIGN="CENTER"> -About -</TD> -<TD> -this page -</TD> -<TD> - -</TD> -</TR> -</TABLE> -<P></P> -where the <STRONG> Example </STRONG> assumes that the current position -is at <STRONG> Subsubsection One-Two-Three </STRONG> of a document of -the following structure: -<UL> -<LI> 1. 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