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Diffstat (limited to 'doc/bash.html')
| -rw-r--r-- | doc/bash.html | 75 |
1 files changed, 63 insertions, 12 deletions
diff --git a/doc/bash.html b/doc/bash.html index b3738b57..287ac3a3 100644 --- a/doc/bash.html +++ b/doc/bash.html @@ -3,7 +3,7 @@ </HEAD> <BODY><TABLE WIDTH=100%> <TR> -<TH ALIGN=LEFT width=33%>BASH(1)<TH ALIGN=CENTER width=33%>2023 April 17<TH ALIGN=RIGHT width=33%>BASH(1) +<TH ALIGN=LEFT width=33%>BASH(1)<TH ALIGN=CENTER width=33%>2023 May 14<TH ALIGN=RIGHT width=33%>BASH(1) </TR> </TABLE> <BR><A HREF="#index">Index</A> @@ -2869,8 +2869,10 @@ and which sort the files on name, file size, modification time, access time, inode change time, and number of blocks, respectively. -For example, a value of <B>-mtime</B> sorts the results in descending +For example, a value of <I>-mtime</I> sorts the results in descending order by modification time (newest first). +A sort specifier of <I>nosort</I> disables sorting completely; the results +are returned in the order they are read from the file system,. If the sort specifier is missing, it defaults to <I>name</I>, so a value of <I>+</I> is equivalent to the null string, and a value of <I>-</I> sorts by name in descending order. @@ -4463,16 +4465,17 @@ expansion as described below. <H4>Command Substitution</H4> <I>Command substitution</I> allows the output of a command to replace -the command name. There are two forms: +the command itself. +There are two standard forms: <DL COMPACT><DT><DD> <P> <B>$(</B><I>command</I><B>)</B> </DL> -or +or (deprecated) <DL COMPACT><DT><DD> -<B>`</B><I>command</I><B>`</B> +<B>`</B><I>command</I><B>`</B>. </DL> <P> @@ -4488,7 +4491,7 @@ The command substitution <B>$(cat </B><I>file</I>) can be replaced by the equivalent but faster <B>$(< </B><I>file</I>). <P> -When the old-style backquote form of substitution is used, +With the old-style backquote form of substitution, backslash retains its literal meaning except when followed by <B>$</B>, @@ -4503,12 +4506,60 @@ When using the $(<I>command</I>) form, all characters between the parentheses make up the command; none are treated specially. <P> +There is an alternate form of command substitution: +<DL COMPACT><DT><DD> +<P> + +<B>${</B><I>C</I> <I>command</I><B>;</B><B>}</B> +</DL> + +<P> + +which executes <I>command</I> in the current execution environment. +This means that side effects of <I>command</I> take effect immediately +in the current execution environment and persist in the current +environment after the command completes (e.g., the <B>exit</B> builtin +will exit the shell). +<P> + +The character <I>C</I> following the open brace must be a space, tab, +newline, <B>(</B>, or <B>|</B>, and the close brace must be in a position +where a reserved word may appear (i.e., preceded by a command terminator +such as semicolon). +<B>Bash</B> allows the close brace to be joined to the remaining characters in +the word without being followed by a shell metacharacter as a reserved +word would usually require. +<P> + +This type of command substitution superficially resembles executing an +unnamed shell function: local variables are created as when a shell +function is executing, and the <B>return</B> builtin forces +<I>command</I> to complete; +however, the rest of the execution environment, +including the positional parameters, is shared with the caller. +<P> + +If the first character following the open brace is a <B>(</B>, +<I>command</I> is executed in a subshell, and <I>command</I> must be +terminated by a <B>)</B>. This is similar to the <B>(</B> compound +command (see <B>Compound Commands</B> above). +If the first character is a <B>|</B>, the construct expands to the +value of the <B>REPLY</B> shell variable after <I>command</I> executes, +without removing any trailing newlines, +and the standard output of <I>command</I> remains the same as in the +calling shell. +<B>Bash</B> creates <B>REPLY</B> as an initially-unset local variable when +<I>command</I> executes, and restores <B>REPLY</B> to the value it had +before the command substitution after <I>command</I> completes, +as with any local variable. +<P> + Command substitutions may be nested. To nest when using the backquoted form, escape the inner backquotes with backslashes. <P> -If the substitution appears within double quotes, word splitting and -pathname expansion are not performed on the results. +If the substitution appears within double quotes, <B>bash</B> does not perform +word splitting and pathname expansion on the results. <A NAME="lbBD"> </A> <H4>Arithmetic Expansion</H4> @@ -11999,7 +12050,7 @@ in the same way as <B>echo -e</B>. <DD> causes <B>printf</B> to output the corresponding <I>argument</I> in a format that can be reused as shell input. -<B>%q</B> and <B>%Q</B> use the <B>$''</B> quoting style if any characters +<B>%q</B> and <B>%Q</B> use the <B>$aqaq</B> quoting style if any characters in the argument string require it, and backslash quoting otherwise. If the format string uses the <I>printf</I> alternate form, these two formats quote the argument string using single quotes. @@ -14944,7 +14995,7 @@ There may be only one active coprocess at a time. <HR> <TABLE WIDTH=100%> <TR> -<TH ALIGN=LEFT width=33%>GNU Bash 5.2<TH ALIGN=CENTER width=33%>2023 April 17<TH ALIGN=RIGHT width=33%>BASH(1) +<TH ALIGN=LEFT width=33%>GNU Bash 5.2<TH ALIGN=CENTER width=33%>2023 May 14<TH ALIGN=RIGHT width=33%>BASH(1) </TR> </TABLE> <HR> @@ -15050,7 +15101,7 @@ There may be only one active coprocess at a time. <DT><A HREF="#lbDI">BUGS</A><DD> </DL> <HR> -This document was created by man2html from bash.1.<BR> -Time: 18 April 2023 10:26:09 EDT +This document was created by man2html from /usr/local/src/bash/bash-20230509/doc/bash.1.<BR> +Time: 14 May 2023 15:37:14 EDT </BODY> </HTML> |