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authorChet Ramey <chet.ramey@case.edu>2012-01-09 08:37:11 -0500
committerChet Ramey <chet.ramey@case.edu>2012-01-09 08:37:11 -0500
commit45c0f7f8e8a72ae10d16f54e9f1850e20592aed1 (patch)
tree908b26efaf4dff3e957891d093b7643824e77563 /doc/bash.0
parenteb4206df3650ed65ccfc8f83b7ebf7681e4ba3e7 (diff)
downloadbash-45c0f7f8e8a72ae10d16f54e9f1850e20592aed1.tar.gz
commit bash-20111229 snapshot
Diffstat (limited to 'doc/bash.0')
-rw-r--r--doc/bash.02692
1 files changed, 1366 insertions, 1326 deletions
diff --git a/doc/bash.0 b/doc/bash.0
index ceb581bf..2249cde7 100644
--- a/doc/bash.0
+++ b/doc/bash.0
@@ -6,7 +6,7 @@ NNAAMMEE
bash - GNU Bourne-Again SHell
SSYYNNOOPPSSIISS
- bbaasshh [options] [file]
+ bbaasshh [options] [command_string | file]
CCOOPPYYRRIIGGHHTT
Bash is Copyright (C) 1989-2011 by the Free Software Foundation, Inc.
@@ -26,76 +26,77 @@ OOPPTTIIOONNSS
is invoked. In addition, bbaasshh interprets the following options when it
is invoked:
- --cc _s_t_r_i_n_g If the --cc option is present, then commands are read from
- _s_t_r_i_n_g. If there are arguments after the _s_t_r_i_n_g, they are
- assigned to the positional parameters, starting with $$00.
+ --cc If the --cc option is present, then commands are read from the
+ first non-option argument _c_o_m_m_a_n_d___s_t_r_i_n_g. If there are argu-
+ ments after the _c_o_m_m_a_n_d___s_t_r_i_n_g, they are assigned to the
+ positional parameters, starting with $$00.
--ii If the --ii option is present, the shell is _i_n_t_e_r_a_c_t_i_v_e.
--ll Make bbaasshh act as if it had been invoked as a login shell (see
IINNVVOOCCAATTIIOONN below).
- --rr If the --rr option is present, the shell becomes _r_e_s_t_r_i_c_t_e_d
+ --rr If the --rr option is present, the shell becomes _r_e_s_t_r_i_c_t_e_d
(see RREESSTTRRIICCTTEEDD SSHHEELLLL below).
- --ss If the --ss 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
+ --ss If the --ss 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.
- --DD A list of all double-quoted strings preceded by $$ is printed
- on the standard output. These are the strings that are sub-
+ --DD A list of all double-quoted strings preceded by $$ is printed
+ on the standard output. These are the strings that are sub-
ject to language translation when the current locale is not CC
- or PPOOSSIIXX. This implies the --nn option; no commands will be
+ or PPOOSSIIXX. This implies the --nn option; no commands will be
executed.
[[--++]]OO [[_s_h_o_p_t___o_p_t_i_o_n]]
- _s_h_o_p_t___o_p_t_i_o_n is one of the shell options accepted by the
- sshhoopptt builtin (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). If
+ _s_h_o_p_t___o_p_t_i_o_n is one of the shell options accepted by the
+ sshhoopptt builtin (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). If
_s_h_o_p_t___o_p_t_i_o_n is present, --OO sets the value of that option; ++OO
- unsets it. If _s_h_o_p_t___o_p_t_i_o_n is not supplied, the names and
- values of the shell options accepted by sshhoopptt are printed on
- the standard output. If the invocation option is ++OO, the
- output is displayed in a format that may be reused as input.
- ---- A ---- signals the end of options and disables further option
- processing. Any arguments after the ---- are treated as file-
+ unsets it. If _s_h_o_p_t___o_p_t_i_o_n is not supplied, the names and
+ values of the shell options accepted by sshhoopptt are printed on
+ the standard output. If the invocation option is ++OO, the
+ output is displayed in a format that may be reused as input.
+ ---- A ---- signals the end of options and disables further option
+ processing. Any arguments after the ---- are treated as file-
names and arguments. An argument of -- is equivalent to ----.
- BBaasshh also interprets a number of multi-character options. These
- options must appear on the command line before the single-character
+ BBaasshh also interprets a number of multi-character options. These
+ options must appear on the command line before the single-character
options to be recognized.
----ddeebbuuggggeerr
Arrange for the debugger profile to be executed before the shell
- starts. Turns on extended debugging mode (see the description
+ starts. Turns on extended debugging mode (see the description
of the eexxttddeebbuugg option to the sshhoopptt builtin below).
----dduummpp--ppoo--ssttrriinnggss
- Equivalent to --DD, but the output is in the GNU _g_e_t_t_e_x_t ppoo (por-
+ Equivalent to --DD, but the output is in the GNU _g_e_t_t_e_x_t ppoo (por-
table object) file format.
----dduummpp--ssttrriinnggss
Equivalent to --DD.
- ----hheellpp Display a usage message on standard output and exit success-
+ ----hheellpp Display a usage message on standard output and exit success-
fully.
----iinniitt--ffiillee _f_i_l_e
----rrccffiillee _f_i_l_e
Execute commands from _f_i_l_e instead of the standard personal ini-
- tialization file _~_/_._b_a_s_h_r_c if the shell is interactive (see
+ tialization file _~_/_._b_a_s_h_r_c if the shell is interactive (see
IINNVVOOCCAATTIIOONN below).
----llooggiinn
Equivalent to --ll.
----nnooeeddiittiinngg
- Do not use the GNU rreeaaddlliinnee library to read command lines when
+ Do not use the GNU rreeaaddlliinnee library to read command lines when
the shell is interactive.
----nnoopprrooffiillee
- Do not read either the system-wide startup file _/_e_t_c_/_p_r_o_f_i_l_e or
- any of the personal initialization files _~_/_._b_a_s_h___p_r_o_f_i_l_e,
- _~_/_._b_a_s_h___l_o_g_i_n, or _~_/_._p_r_o_f_i_l_e. By default, bbaasshh reads these
- files when it is invoked as a login shell (see IINNVVOOCCAATTIIOONN
+ Do not read either the system-wide startup file _/_e_t_c_/_p_r_o_f_i_l_e or
+ any of the personal initialization files _~_/_._b_a_s_h___p_r_o_f_i_l_e,
+ _~_/_._b_a_s_h___l_o_g_i_n, or _~_/_._p_r_o_f_i_l_e. By default, bbaasshh reads these
+ files when it is invoked as a login shell (see IINNVVOOCCAATTIIOONN
below).
----nnoorrcc Do not read and execute the personal initialization file
- _~_/_._b_a_s_h_r_c if the shell is interactive. This option is on by
+ _~_/_._b_a_s_h_r_c if the shell is interactive. This option is on by
default if the shell is invoked as sshh.
----ppoossiixx
- Change the behavior of bbaasshh where the default operation differs
+ Change the behavior of bbaasshh where the default operation differs
from the POSIX standard to match the standard (_p_o_s_i_x _m_o_d_e).
----rreessttrriicctteedd
@@ -105,113 +106,113 @@ OOPPTTIIOONNSS
Equivalent to --vv.
----vveerrssiioonn
- Show version information for this instance of bbaasshh on the stan-
+ Show version information for this instance of bbaasshh on the stan-
dard output and exit successfully.
AARRGGUUMMEENNTTSS
If arguments remain after option processing, and neither the --cc nor the
- --ss option has been supplied, the first argument is assumed to be the
- name of a file containing shell commands. If bbaasshh is invoked in this
- fashion, $$00 is set to the name of the file, and the positional parame-
- ters are set to the remaining arguments. BBaasshh reads and executes com-
- mands from this file, then exits. BBaasshh's exit status is the exit sta-
- tus of the last command executed in the script. If no commands are
- executed, the exit status is 0. An attempt is first made to open the
+ --ss option has been supplied, the first argument is assumed to be the
+ name of a file containing shell commands. If bbaasshh is invoked in this
+ fashion, $$00 is set to the name of the file, and the positional parame-
+ ters are set to the remaining arguments. BBaasshh reads and executes com-
+ mands from this file, then exits. BBaasshh's exit status is the exit sta-
+ tus of the last command executed in the script. If no commands are
+ executed, the exit status is 0. An attempt is first made to open the
file in the current directory, and, if no file is found, then the shell
searches the directories in PPAATTHH for the script.
IINNVVOOCCAATTIIOONN
- A _l_o_g_i_n _s_h_e_l_l is one whose first character of argument zero is a --, or
+ A _l_o_g_i_n _s_h_e_l_l is one whose first character of argument zero is a --, or
one started with the ----llooggiinn option.
- An _i_n_t_e_r_a_c_t_i_v_e shell is one started without non-option arguments and
+ An _i_n_t_e_r_a_c_t_i_v_e shell is one started without non-option arguments and
without the --cc option whose standard input and error are both connected
- to terminals (as determined by _i_s_a_t_t_y(3)), or one started with the --ii
- option. PPSS11 is set and $$-- includes ii if bbaasshh is interactive, allowing
+ to terminals (as determined by _i_s_a_t_t_y(3)), or one started with the --ii
+ option. PPSS11 is set and $$-- includes ii if bbaasshh is interactive, allowing
a shell script or a startup file to test this state.
- The following paragraphs describe how bbaasshh executes its startup files.
- If any of the files exist but cannot be read, bbaasshh reports an error.
- Tildes are expanded in filenames as described below under TTiillddee EExxppaann--
+ The following paragraphs describe how bbaasshh executes its startup files.
+ If any of the files exist but cannot be read, bbaasshh reports an error.
+ Tildes are expanded in filenames as described below under TTiillddee EExxppaann--
ssiioonn in the EEXXPPAANNSSIIOONN section.
- When bbaasshh is invoked as an interactive login shell, or as a non-inter-
- active shell with the ----llooggiinn option, it first reads and executes com-
- mands from the file _/_e_t_c_/_p_r_o_f_i_l_e, if that file exists. After reading
+ When bbaasshh is invoked as an interactive login shell, or as a non-inter-
+ active shell with the ----llooggiinn option, it first reads and executes com-
+ mands from the file _/_e_t_c_/_p_r_o_f_i_l_e, if that file exists. After reading
that file, it looks for _~_/_._b_a_s_h___p_r_o_f_i_l_e, _~_/_._b_a_s_h___l_o_g_i_n, and _~_/_._p_r_o_f_i_l_e,
- in that order, and reads and executes commands from the first one that
- exists and is readable. The ----nnoopprrooffiillee option may be used when the
+ in that order, and reads and executes commands from the first one that
+ exists and is readable. The ----nnoopprrooffiillee option may be used when the
shell is started to inhibit this behavior.
- When a login shell exits, bbaasshh reads and executes commands from the
+ When a login shell exits, bbaasshh reads and executes commands from the
file _~_/_._b_a_s_h___l_o_g_o_u_t, if it exists.
- When an interactive shell that is not a login shell is started, bbaasshh
- reads and executes commands from _~_/_._b_a_s_h_r_c, if that file exists. This
- may be inhibited by using the ----nnoorrcc option. The ----rrccffiillee _f_i_l_e option
- will force bbaasshh to read and execute commands from _f_i_l_e instead of
+ When an interactive shell that is not a login shell is started, bbaasshh
+ reads and executes commands from _~_/_._b_a_s_h_r_c, if that file exists. This
+ may be inhibited by using the ----nnoorrcc option. The ----rrccffiillee _f_i_l_e option
+ will force bbaasshh to read and execute commands from _f_i_l_e instead of
_~_/_._b_a_s_h_r_c.
- When bbaasshh is started non-interactively, to run a shell script, for
+ When bbaasshh is started non-interactively, to run a shell script, for
example, it looks for the variable BBAASSHH__EENNVV 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. BBaasshh behaves as if the following com-
+ its value if it appears there, and uses the expanded value as the name
+ of a file to read and execute. BBaasshh behaves as if the following com-
mand were executed:
if [ -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi
- but the value of the PPAATTHH variable is not used to search for the file-
+ but the value of the PPAATTHH variable is not used to search for the file-
name.
- If bbaasshh is invoked with the name sshh, it tries to mimic the startup
- behavior of historical versions of sshh as closely as possible, while
- conforming to the POSIX standard as well. When invoked as an interac-
- tive login shell, or a non-interactive shell with the ----llooggiinn option,
- it first attempts to read and execute commands from _/_e_t_c_/_p_r_o_f_i_l_e and
- _~_/_._p_r_o_f_i_l_e, in that order. The ----nnoopprrooffiillee option may be used to
- inhibit this behavior. When invoked as an interactive shell with the
- name sshh, bbaasshh looks for the variable EENNVV, expands its value if it is
- defined, and uses the expanded value as the name of a file to read and
+ If bbaasshh is invoked with the name sshh, it tries to mimic the startup
+ behavior of historical versions of sshh as closely as possible, while
+ conforming to the POSIX standard as well. When invoked as an interac-
+ tive login shell, or a non-interactive shell with the ----llooggiinn option,
+ it first attempts to read and execute commands from _/_e_t_c_/_p_r_o_f_i_l_e and
+ _~_/_._p_r_o_f_i_l_e, in that order. The ----nnoopprrooffiillee option may be used to
+ inhibit this behavior. When invoked as an interactive shell with the
+ name sshh, bbaasshh looks for the variable EENNVV, 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 sshh does not attempt to read and exe-
- cute commands from any other startup files, the ----rrccffiillee option has no
- effect. A non-interactive shell invoked with the name sshh does not
- attempt to read any other startup files. When invoked as sshh, bbaasshh
+ cute commands from any other startup files, the ----rrccffiillee option has no
+ effect. A non-interactive shell invoked with the name sshh does not
+ attempt to read any other startup files. When invoked as sshh, bbaasshh
enters _p_o_s_i_x mode after the startup files are read.
- When bbaasshh is started in _p_o_s_i_x mode, as with the ----ppoossiixx command line
+ When bbaasshh is started in _p_o_s_i_x mode, as with the ----ppoossiixx command line
option, it follows the POSIX standard for startup files. In this mode,
- interactive shells expand the EENNVV variable and commands are read and
- executed from the file whose name is the expanded value. No other
+ interactive shells expand the EENNVV variable and commands are read and
+ executed from the file whose name is the expanded value. No other
startup files are read.
BBaasshh attempts to determine when it is being run with its standard input
connected to a network connection, as when executed by the remote shell
- daemon, usually _r_s_h_d, or the secure shell daemon _s_s_h_d. If bbaasshh deter-
- mines it is being run in this fashion, it reads and executes commands
- from _~_/_._b_a_s_h_r_c, if that file exists and is readable. It will not do
- this if invoked as sshh. The ----nnoorrcc option may be used to inhibit this
- behavior, and the ----rrccffiillee option may be used to force another file to
- be read, but _r_s_h_d does not generally invoke the shell with those
+ daemon, usually _r_s_h_d, or the secure shell daemon _s_s_h_d. If bbaasshh deter-
+ mines it is being run in this fashion, it reads and executes commands
+ from _~_/_._b_a_s_h_r_c, if that file exists and is readable. It will not do
+ this if invoked as sshh. The ----nnoorrcc option may be used to inhibit this
+ behavior, and the ----rrccffiillee option may be used to force another file to
+ be read, but _r_s_h_d does not generally invoke the shell with those
options or allow them to be specified.
If the shell is started with the effective user (group) id not equal to
the real user (group) id, and the --pp option is not supplied, no startup
files are read, shell functions are not inherited from the environment,
- the SSHHEELLLLOOPPTTSS, BBAASSHHOOPPTTSS, CCDDPPAATTHH, and GGLLOOBBIIGGNNOORREE variables, if they
- appear in the environment, are ignored, and the effective user id is
- set to the real user id. If the --pp option is supplied at invocation,
- the startup behavior is the same, but the effective user id is not
+ the SSHHEELLLLOOPPTTSS, BBAASSHHOOPPTTSS, CCDDPPAATTHH, and GGLLOOBBIIGGNNOORREE variables, if they
+ appear in the environment, are ignored, and the effective user id is
+ set to the real user id. If the --pp option is supplied at invocation,
+ the startup behavior is the same, but the effective user id is not
reset.
DDEEFFIINNIITTIIOONNSS
- The following definitions are used throughout the rest of this docu-
+ The following definitions are used throughout the rest of this docu-
ment.
bbllaannkk A space or tab.
- wwoorrdd A sequence of characters considered as a single unit by the
+ wwoorrdd A sequence of characters considered as a single unit by the
shell. Also known as a ttookkeenn.
- nnaammee A _w_o_r_d consisting only of alphanumeric characters and under-
- scores, and beginning with an alphabetic character or an under-
+ nnaammee A _w_o_r_d consisting only of alphanumeric characters and under-
+ scores, and beginning with an alphabetic character or an under-
score. Also referred to as an iiddeennttiiffiieerr.
mmeettaacchhaarraacctteerr
- A character that, when unquoted, separates words. One of the
+ A character that, when unquoted, separates words. One of the
following:
|| && ;; (( )) << >> ssppaaccee ttaabb
ccoonnttrrooll ooppeerraattoorr
@@ -222,88 +223,88 @@ DDEEFFIINNIITTIIOONNSS
RREESSEERRVVEEDD WWOORRDDSS
_R_e_s_e_r_v_e_d _w_o_r_d_s are words that have a special meaning to the shell. The
following words are recognized as reserved when unquoted and either the
- first word of a simple command (see SSHHEELLLL GGRRAAMMMMAARR below) or the third
+ first word of a simple command (see SSHHEELLLL GGRRAAMMMMAARR below) or the third
word of a ccaassee or ffoorr command:
- !! ccaassee ddoo ddoonnee eelliiff eellssee eessaacc ffii ffoorr ffuunnccttiioonn iiff iinn sseelleecctt tthheenn uunnttiill
+ !! ccaassee ddoo ddoonnee eelliiff eellssee eessaacc ffii ffoorr ffuunnccttiioonn iiff iinn sseelleecctt tthheenn uunnttiill
wwhhiillee {{ }} ttiimmee [[[[ ]]]]
SSHHEELLLL GGRRAAMMMMAARR
SSiimmppllee CCoommmmaannddss
- A _s_i_m_p_l_e _c_o_m_m_a_n_d is a sequence of optional variable assignments fol-
- lowed by bbllaannkk-separated words and redirections, and terminated by a
+ A _s_i_m_p_l_e _c_o_m_m_a_n_d is a sequence of optional variable assignments fol-
+ lowed by bbllaannkk-separated words and redirections, and terminated by a
_c_o_n_t_r_o_l _o_p_e_r_a_t_o_r. The first word specifies the command to be executed,
- and is passed as argument zero. The remaining words are passed as
+ and is passed as argument zero. The remaining words are passed as
arguments to the invoked command.
- The return value of a _s_i_m_p_l_e _c_o_m_m_a_n_d is its exit status, or 128+_n if
+ The return value of a _s_i_m_p_l_e _c_o_m_m_a_n_d is its exit status, or 128+_n if
the command is terminated by signal _n.
PPiippeelliinneess
- A _p_i_p_e_l_i_n_e is a sequence of one or more commands separated by one of
+ A _p_i_p_e_l_i_n_e is a sequence of one or more commands separated by one of
the control operators || or ||&&. The format for a pipeline is:
[ttiimmee [--pp]] [ ! ] _c_o_m_m_a_n_d [ [|||||&&] _c_o_m_m_a_n_d_2 ... ]
- The standard output of _c_o_m_m_a_n_d is connected via a pipe to the standard
- input of _c_o_m_m_a_n_d_2. This connection is performed before any redirec-
+ The standard output of _c_o_m_m_a_n_d is connected via a pipe to the standard
+ input of _c_o_m_m_a_n_d_2. This connection is performed before any redirec-
tions specified by the command (see RREEDDIIRREECCTTIIOONN below). If ||&& is used,
- _c_o_m_m_a_n_d's standard output and standard error are connected to _c_o_m_-
- _m_a_n_d_2's standard input through the pipe; it is shorthand for 22>>&&11 ||.
- This implicit redirection of the standard error is performed after any
+ _c_o_m_m_a_n_d's standard output and standard error are connected to _c_o_m_-
+ _m_a_n_d_2's standard input through the pipe; it is shorthand for 22>>&&11 ||.
+ This implicit redirection of the standard error is performed after any
redirections specified by the command.
The return status of a pipeline is the exit status of the last command,
- unless the ppiippeeffaaiill option is enabled. If ppiippeeffaaiill 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 success-
+ unless the ppiippeeffaaiill option is enabled. If ppiippeeffaaiill 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 success-
fully. If the reserved word !! precedes a pipeline, the exit status of
- that pipeline is the logical negation of the exit status as described
- above. The shell waits for all commands in the pipeline to terminate
+ that pipeline 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.
- If the ttiimmee reserved word precedes a pipeline, the elapsed as well as
- user and system time consumed by its execution are reported when the
- pipeline terminates. The --pp option changes the output format to that
- specified by POSIX. When the shell is in _p_o_s_i_x _m_o_d_e, it does not rec-
- ognize ttiimmee as a reserved word if the next token begins with a `-'.
- The TTIIMMEEFFOORRMMAATT variable may be set to a format string that specifies
- how the timing information should be displayed; see the description of
+ If the ttiimmee reserved word precedes a pipeline, the elapsed as well as
+ user and system time consumed by its execution are reported when the
+ pipeline terminates. The --pp option changes the output format to that
+ specified by POSIX. When the shell is in _p_o_s_i_x _m_o_d_e, it does not rec-
+ ognize ttiimmee as a reserved word if the next token begins with a `-'.
+ The TTIIMMEEFFOORRMMAATT variable may be set to a format string that specifies
+ how the timing information should be displayed; see the description of
TTIIMMEEFFOORRMMAATT under SShheellll VVaarriiaabblleess below.
When the shell is in _p_o_s_i_x _m_o_d_e, ttiimmee may be followed by a newline. In
- this case, the shell displays the total user and system time consumed
- by the shell and its children. The TTIIMMEEFFOORRMMAATT variable may be used to
+ this case, the shell displays the total user and system time consumed
+ by the shell and its children. The TTIIMMEEFFOORRMMAATT variable may be used to
specify the format of the time information.
- Each command in a pipeline is executed as a separate process (i.e., in
+ Each command in a pipeline is executed as a separate process (i.e., in
a subshell).
LLiissttss
- A _l_i_s_t is a sequence of one or more pipelines separated by one of the
+ A _l_i_s_t is a sequence of one or more pipelines separated by one of the
operators ;;, &&, &&&&, or ||||, and optionally terminated by one of ;;, &&, or
<<nneewwlliinnee>>.
Of these list operators, &&&& and |||| have equal precedence, followed by ;;
and &&, which have equal precedence.
- A sequence of one or more newlines may appear in a _l_i_s_t instead of a
+ A sequence of one or more newlines may appear in a _l_i_s_t instead of a
semicolon to delimit commands.
- If a command is terminated by the control operator &&, the shell exe-
- cutes the command in the _b_a_c_k_g_r_o_u_n_d in a subshell. The shell does not
- wait for the command to finish, and the return status is 0. Commands
- separated by a ;; are executed sequentially; the shell waits for each
- command to terminate in turn. The return status is the exit status of
+ If a command is terminated by the control operator &&, the shell exe-
+ cutes the command in the _b_a_c_k_g_r_o_u_n_d in a subshell. The shell does not
+ wait for the command to finish, and the return status is 0. Commands
+ separated by a ;; 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.
- AND and OR lists are sequences of one of more pipelines separated by
- the &&&& and |||| control operators, respectively. AND and OR lists are
+ AND and OR lists are sequences of one of more pipelines separated by
+ the &&&& and |||| control operators, respectively. AND and OR lists are
executed with left associativity. An AND list has the form
_c_o_m_m_a_n_d_1 &&&& _c_o_m_m_a_n_d_2
- _c_o_m_m_a_n_d_2 is executed if, and only if, _c_o_m_m_a_n_d_1 returns an exit status
+ _c_o_m_m_a_n_d_2 is executed if, and only if, _c_o_m_m_a_n_d_1 returns an exit status
of zero.
An OR list has the form
@@ -311,83 +312,87 @@ SSHHEELLLL GGRRAAMMMMAARR
_c_o_m_m_a_n_d_1 |||| _c_o_m_m_a_n_d_2
- _c_o_m_m_a_n_d_2 is executed if and only if _c_o_m_m_a_n_d_1 returns a non-zero exit
- status. The return status of AND and OR lists is the exit status of
+ _c_o_m_m_a_n_d_2 is executed if and only if _c_o_m_m_a_n_d_1 returns a non-zero exit
+ status. The return status of AND and OR lists is the exit status of
the last command executed in the list.
CCoommppoouunndd CCoommmmaannddss
- A _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d is one of the following. In most cases a _l_i_s_t in a
- command's description may be separated from the rest of the command by
- one or more newlines, and may be followed by a newline in place of a
+ A _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d is one of the following. In most cases a _l_i_s_t in a
+ command's description may be separated from the rest of the command by
+ one or more newlines, and may be followed by a newline in place of a
semicolon.
- (_l_i_s_t) _l_i_s_t is executed in a subshell environment (see CCOOMMMMAANNDD EEXXEECCUU--
- TTIIOONN EENNVVIIRROONNMMEENNTT below). Variable assignments and builtin com-
- mands that affect the shell's environment do not remain in
- effect after the command completes. The return status is the
+ (_l_i_s_t) _l_i_s_t is executed in a subshell environment (see CCOOMMMMAANNDD EEXXEECCUU--
+ TTIIOONN EENNVVIIRROONNMMEENNTT below). Variable assignments and builtin com-
+ mands that affect the shell's environment do not remain in
+ effect after the command completes. The return status is the
exit status of _l_i_s_t.
{ _l_i_s_t; }
- _l_i_s_t is simply executed in the current shell environment. _l_i_s_t
- must be terminated with a newline or semicolon. This is known
- as a _g_r_o_u_p _c_o_m_m_a_n_d. The return status is the exit status of
- _l_i_s_t. Note that unlike the metacharacters (( and )), {{ and }} are
+ _l_i_s_t is simply executed in the current shell environment. _l_i_s_t
+ must be terminated with a newline or semicolon. This is known
+ as a _g_r_o_u_p _c_o_m_m_a_n_d. The return status is the exit status of
+ _l_i_s_t. Note that unlike the metacharacters (( and )), {{ and }} are
_r_e_s_e_r_v_e_d _w_o_r_d_s and must occur where a reserved word is permitted
- to be recognized. Since they do not cause a word break, they
- must be separated from _l_i_s_t by whitespace or another shell
+ to be recognized. Since they do not cause a word break, they
+ must be separated from _l_i_s_t by whitespace or another shell
metacharacter.
((_e_x_p_r_e_s_s_i_o_n))
- The _e_x_p_r_e_s_s_i_o_n is evaluated according to the rules described
- below under AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. If the value of the expres-
- sion is non-zero, the return status is 0; otherwise the return
+ The _e_x_p_r_e_s_s_i_o_n is evaluated according to the rules described
+ below under AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. If the value of the expres-
+ sion is non-zero, the return status is 0; otherwise the return
status is 1. This is exactly equivalent to lleett ""_e_x_p_r_e_s_s_i_o_n"".
[[[[ _e_x_p_r_e_s_s_i_o_n ]]]]
- Return a status of 0 or 1 depending on the evaluation of the
- conditional expression _e_x_p_r_e_s_s_i_o_n. Expressions are composed of
- the primaries described below under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS.
- Word splitting and pathname expansion are not performed on the
- words between the [[[[ and ]]]]; tilde expansion, parameter and
- variable expansion, arithmetic expansion, command substitution,
- process substitution, and quote removal are performed. Condi-
+ Return a status of 0 or 1 depending on the evaluation of the
+ conditional expression _e_x_p_r_e_s_s_i_o_n. Expressions are composed of
+ the primaries described below under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS.
+ Word splitting and pathname expansion are not performed on the
+ words between the [[[[ and ]]]]; tilde expansion, parameter and
+ variable expansion, arithmetic expansion, command substitution,
+ process substitution, and quote removal are performed. Condi-
tional operators such as --ff must be unquoted to be recognized as
primaries.
- When used with [[[[, the << and >> operators sort lexicographically
+ When used with [[[[, the << and >> operators sort lexicographically
using the current locale.
- When the ==== and !!== operators are used, the string to the right
+ When the ==== and !!== operators are used, the string to the right
of the operator is considered a pattern and matched according to
- the rules described below under PPaatttteerrnn MMaattcchhiinngg. If the shell
- option nnooccaasseemmaattcchh is enabled, the match is performed without
- regard to the case of alphabetic characters. The return value
- is 0 if the string matches (====) or does not match (!!==) the pat-
+ the rules described below under PPaatttteerrnn MMaattcchhiinngg. If the shell
+ option nnooccaasseemmaattcchh is enabled, the match is performed without
+ regard to the case of alphabetic characters. The return value
+ is 0 if the string matches (====) or does not match (!!==) the pat-
tern, and 1 otherwise. Any part of the pattern may be quoted to
force the quoted portion to be matched as a string.
- An additional binary operator, ==~~, is available, with the same
- precedence as ==== and !!==. When it is used, the string to the
- right of the operator is considered an extended regular expres-
+ An additional binary operator, ==~~, is available, with the same
+ precedence as ==== and !!==. When it is used, the string to the
+ right of the operator is considered an extended regular expres-
sion and matched accordingly (as in _r_e_g_e_x(3)). The return value
is 0 if the string matches the pattern, and 1 otherwise. If the
- regular expression is syntactically incorrect, the conditional
+ regular expression is syntactically incorrect, the conditional
expression's return value is 2. If the shell option nnooccaasseemmaattcchh
is enabled, the match is performed without regard to the case of
alphabetic characters. Any part of the pattern may be quoted to
- force the quoted portion to be matched as a string. Substrings
- matched by parenthesized subexpressions within the regular
- expression are saved in the array variable BBAASSHH__RREEMMAATTCCHH. The
- element of BBAASSHH__RREEMMAATTCCHH with index 0 is the portion of the
- string matching the entire regular expression. The element of
- BBAASSHH__RREEMMAATTCCHH with index _n is the portion of the string matching
- the _nth parenthesized subexpression.
-
- Expressions may be combined using the following operators,
+ force the quoted portion to be matched as a string. Bracket
+ expressions in regular expressions must be treated carefully,
+ since normal quoting characters lose their meanings between
+ brackets. If the pattern is stored in a shell variable, quoting
+ the variable expansion forces the entire pattern to be matched
+ as a string. Substrings matched by parenthesized subexpressions
+ within the regular expression are saved in the array variable
+ BBAASSHH__RREEMMAATTCCHH. The element of BBAASSHH__RREEMMAATTCCHH with index 0 is the
+ portion of the string matching the entire regular expression.
+ The element of BBAASSHH__RREEMMAATTCCHH with index _n is the portion of the
+ string matching the _nth parenthesized subexpression.
+
+ Expressions may be combined using the following operators,
listed in decreasing order of precedence:
(( _e_x_p_r_e_s_s_i_o_n ))
- Returns the value of _e_x_p_r_e_s_s_i_o_n. This may be used to
+ Returns the value of _e_x_p_r_e_s_s_i_o_n. This may be used to
override the normal precedence of operators.
!! _e_x_p_r_e_s_s_i_o_n
True if _e_x_p_r_e_s_s_i_o_n is false.
@@ -397,190 +402,190 @@ SSHHEELLLL GGRRAAMMMMAARR
True if either _e_x_p_r_e_s_s_i_o_n_1 or _e_x_p_r_e_s_s_i_o_n_2 is true.
The &&&& and |||| operators do not evaluate _e_x_p_r_e_s_s_i_o_n_2 if the value
- of _e_x_p_r_e_s_s_i_o_n_1 is sufficient to determine the return value of
+ of _e_x_p_r_e_s_s_i_o_n_1 is sufficient to determine the return value of
the entire conditional expression.
ffoorr _n_a_m_e [ [ iinn [ _w_o_r_d _._._. ] ] ; ] ddoo _l_i_s_t ; ddoonnee
The list of words following iinn is expanded, generating a list of
items. The variable _n_a_m_e is set to each element of this list in
- turn, and _l_i_s_t is executed each time. If the iinn _w_o_r_d is omit-
- ted, the ffoorr command executes _l_i_s_t once for each positional
+ turn, and _l_i_s_t is executed each time. If the iinn _w_o_r_d is omit-
+ ted, the ffoorr command executes _l_i_s_t once for each positional
parameter that is set (see PPAARRAAMMEETTEERRSS below). The return status
- is the exit status of the last command that executes. If the
+ is the exit status of the last command that executes. If the
expansion of the items following iinn results in an empty list, no
commands are executed, and the return status is 0.
ffoorr (( _e_x_p_r_1 ; _e_x_p_r_2 ; _e_x_p_r_3 )) ; ddoo _l_i_s_t ; ddoonnee
First, the arithmetic expression _e_x_p_r_1 is evaluated according to
- the rules described below under AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. The
- arithmetic expression _e_x_p_r_2 is then evaluated repeatedly until
- it evaluates to zero. Each time _e_x_p_r_2 evaluates to a non-zero
- value, _l_i_s_t is executed and the arithmetic expression _e_x_p_r_3 is
- evaluated. If any expression is omitted, it behaves as if it
+ the rules described below under AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. The
+ arithmetic expression _e_x_p_r_2 is then evaluated repeatedly until
+ it evaluates to zero. Each time _e_x_p_r_2 evaluates to a non-zero
+ value, _l_i_s_t is executed and the arithmetic expression _e_x_p_r_3 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 _l_i_s_t that is executed, or false if any of the expres-
sions is invalid.
sseelleecctt _n_a_m_e [ iinn _w_o_r_d ] ; ddoo _l_i_s_t ; ddoonnee
The list of words following iinn is expanded, generating a list of
- items. The set of expanded words is printed on the standard
- error, each preceded by a number. If the iinn _w_o_r_d is omitted,
- the positional parameters are printed (see PPAARRAAMMEETTEERRSS below).
- The PPSS33 prompt is then displayed and a line read from the stan-
- dard input. If the line consists of a number corresponding to
- one of the displayed words, then the value of _n_a_m_e is set to
- that word. If the line is empty, the words and prompt are dis-
+ items. The set of expanded words is printed on the standard
+ error, each preceded by a number. If the iinn _w_o_r_d is omitted,
+ the positional parameters are printed (see PPAARRAAMMEETTEERRSS below).
+ The PPSS33 prompt is then displayed and a line read from the stan-
+ dard input. If the line consists of a number corresponding to
+ one of the displayed words, then the value of _n_a_m_e is set to
+ that word. If the line is empty, the words and prompt are dis-
played again. If EOF is read, the command completes. Any other
- value read causes _n_a_m_e to be set to null. The line read is
- saved in the variable RREEPPLLYY. The _l_i_s_t is executed after each
+ value read causes _n_a_m_e to be set to null. The line read is
+ saved in the variable RREEPPLLYY. The _l_i_s_t is executed after each
selection until a bbrreeaakk command is executed. The exit status of
- sseelleecctt is the exit status of the last command executed in _l_i_s_t,
+ sseelleecctt is the exit status of the last command executed in _l_i_s_t,
or zero if no commands were executed.
ccaassee _w_o_r_d iinn [ [(] _p_a_t_t_e_r_n [ || _p_a_t_t_e_r_n ] ... ) _l_i_s_t ;; ] ... eessaacc
A ccaassee command first expands _w_o_r_d, and tries to match it against
each _p_a_t_t_e_r_n in turn, using the same matching rules as for path-
- name expansion (see PPaatthhnnaammee EExxppaannssiioonn below). The _w_o_r_d is
- expanded using tilde expansion, parameter and variable expan-
- sion, arithmetic substitution, command substitution, process
- substitution and quote removal. Each _p_a_t_t_e_r_n examined is
+ name expansion (see PPaatthhnnaammee EExxppaannssiioonn below). The _w_o_r_d is
expanded using tilde expansion, parameter and variable expan-
+ sion, arithmetic substitution, command substitution, process
+ substitution and quote removal. Each _p_a_t_t_e_r_n examined is
+ expanded using tilde expansion, parameter and variable expan-
sion, arithmetic substitution, command substitution, and process
- substitution. If the shell option nnooccaasseemmaattcchh is enabled, the
- match is performed without regard to the case of alphabetic
- characters. When a match is found, the corresponding _l_i_s_t is
+ substitution. If the shell option nnooccaasseemmaattcchh is enabled, the
+ match is performed without regard to the case of alphabetic
+ characters. When a match is found, the corresponding _l_i_s_t is
executed. If the ;;;; operator is used, no subsequent matches are
- attempted after the first pattern match. Using ;;&& in place of
- ;;;; causes execution to continue with the _l_i_s_t associated with
- the next set of patterns. Using ;;;;&& in place of ;;;; causes the
- shell to test the next pattern list in the statement, if any,
+ attempted after the first pattern match. Using ;;&& in place of
+ ;;;; causes execution to continue with the _l_i_s_t associated with
+ the next set of patterns. Using ;;;;&& in place of ;;;; causes the
+ shell to test the next pattern list in the statement, if any,
and execute any associated _l_i_s_t on a successful match. The exit
status is zero if no pattern matches. Otherwise, it is the exit
status of the last command executed in _l_i_s_t.
iiff _l_i_s_t; tthheenn _l_i_s_t_; [ eelliiff _l_i_s_t; tthheenn _l_i_s_t; ] ... [ eellssee _l_i_s_t; ] ffii
- The iiff _l_i_s_t is executed. If its exit status is zero, the tthheenn
- _l_i_s_t is executed. Otherwise, each eelliiff _l_i_s_t is executed in
- turn, and if its exit status is zero, the corresponding tthheenn
+ The iiff _l_i_s_t is executed. If its exit status is zero, the tthheenn
+ _l_i_s_t is executed. Otherwise, each eelliiff _l_i_s_t is executed in
+ turn, and if its exit status is zero, the corresponding tthheenn
_l_i_s_t is executed and the command completes. Otherwise, the eellssee
- _l_i_s_t is executed, if present. The exit status is the exit sta-
+ _l_i_s_t is executed, if present. The exit status is the exit sta-
tus of the last command executed, or zero if no condition tested
true.
wwhhiillee _l_i_s_t_-_1; ddoo _l_i_s_t_-_2; ddoonnee
uunnttiill _l_i_s_t_-_1; ddoo _l_i_s_t_-_2; ddoonnee
- The wwhhiillee command continuously executes the list _l_i_s_t_-_2 as long
+ The wwhhiillee command continuously executes the list _l_i_s_t_-_2 as long
as the last command in the list _l_i_s_t_-_1 returns an exit status of
- zero. The uunnttiill command is identical to the wwhhiillee command,
- except that the test is negated; _l_i_s_t_-_2 is executed as long as
- the last command in _l_i_s_t_-_1 returns a non-zero exit status. The
- exit status of the wwhhiillee and uunnttiill commands is the exit status
+ zero. The uunnttiill command is identical to the wwhhiillee command,
+ except that the test is negated; _l_i_s_t_-_2 is executed as long as
+ the last command in _l_i_s_t_-_1 returns a non-zero exit status. The
+ exit status of the wwhhiillee and uunnttiill commands is the exit status
of the last command executed in _l_i_s_t_-_2, or zero if none was exe-
cuted.
CCoopprroocceesssseess
A _c_o_p_r_o_c_e_s_s is a shell command preceded by the ccoopprroocc reserved word. A
- coprocess is executed asynchronously in a subshell, as if the command
- had been terminated with the && control operator, with a two-way pipe
+ coprocess is executed asynchronously in a subshell, as if the command
+ had been terminated with the && control operator, with a two-way pipe
established between the executing shell and the coprocess.
The format for a coprocess is:
ccoopprroocc [_N_A_M_E] _c_o_m_m_a_n_d [_r_e_d_i_r_e_c_t_i_o_n_s]
- This creates a coprocess named _N_A_M_E. If _N_A_M_E is not supplied, the
+ This creates a coprocess named _N_A_M_E. If _N_A_M_E is not supplied, the
default name is CCOOPPRROOCC. _N_A_M_E must not be supplied if _c_o_m_m_a_n_d is a _s_i_m_-
_p_l_e _c_o_m_m_a_n_d (see above); otherwise, it is interpreted as the first word
- of the simple command. When the coprocess is executed, the shell cre-
- ates an array variable (see AArrrraayyss below) named _N_A_M_E in the context of
+ of the simple command. When the coprocess is executed, the shell cre-
+ ates an array variable (see AArrrraayyss below) named _N_A_M_E in the context of
the executing shell. The standard output of _c_o_m_m_a_n_d is connected via a
- pipe to a file descriptor in the executing shell, and that file
- descriptor is assigned to _N_A_M_E[0]. The standard input of _c_o_m_m_a_n_d is
- connected via a pipe to a file descriptor in the executing shell, and
- that file descriptor is assigned to _N_A_M_E[1]. This pipe is established
- before any redirections specified by the command (see RREEDDIIRREECCTTIIOONN
- below). The file descriptors can be utilized as arguments to shell
- commands and redirections using standard word expansions. The process
- ID of the shell spawned to execute the coprocess is available as the
- value of the variable _N_A_M_E_PID. The wwaaiitt builtin command may be used
+ pipe to a file descriptor in the executing shell, and that file
+ descriptor is assigned to _N_A_M_E[0]. The standard input of _c_o_m_m_a_n_d is
+ connected via a pipe to a file descriptor in the executing shell, and
+ that file descriptor is assigned to _N_A_M_E[1]. This pipe is established
+ before any redirections specified by the command (see RREEDDIIRREECCTTIIOONN
+ below). The file descriptors can be utilized as arguments to shell
+ commands and redirections using standard word expansions. The process
+ ID of the shell spawned to execute the coprocess is available as the
+ value of the variable _N_A_M_E_PID. The wwaaiitt builtin command may be used
to wait for the coprocess to terminate.
The return status of a coprocess is the exit status of _c_o_m_m_a_n_d.
SShheellll FFuunnccttiioonn DDeeffiinniittiioonnss
- A shell function is an object that is called like a simple command and
- executes a compound command with a new set of positional parameters.
+ A shell function is an object that is called like a simple command and
+ executes a compound command with a new set of positional parameters.
Shell functions are declared as follows:
_n_a_m_e () _c_o_m_p_o_u_n_d_-_c_o_m_m_a_n_d [_r_e_d_i_r_e_c_t_i_o_n]
ffuunnccttiioonn _n_a_m_e [()] _c_o_m_p_o_u_n_d_-_c_o_m_m_a_n_d [_r_e_d_i_r_e_c_t_i_o_n]
- This defines a function named _n_a_m_e. The reserved word ffuunnccttiioonn
- is optional. If the ffuunnccttiioonn reserved word is supplied, the
- parentheses are optional. The _b_o_d_y of the function is the com-
- pound command _c_o_m_p_o_u_n_d_-_c_o_m_m_a_n_d (see CCoommppoouunndd CCoommmmaannddss above).
- That command is usually a _l_i_s_t of commands between { and }, but
- may be any command listed under CCoommppoouunndd CCoommmmaannddss above. _c_o_m_-
+ This defines a function named _n_a_m_e. The reserved word ffuunnccttiioonn
+ is optional. If the ffuunnccttiioonn reserved word is supplied, the
+ parentheses are optional. The _b_o_d_y of the function is the com-
+ pound command _c_o_m_p_o_u_n_d_-_c_o_m_m_a_n_d (see CCoommppoouunndd CCoommmmaannddss above).
+ That command is usually a _l_i_s_t of commands between { and }, but
+ may be any command listed under CCoommppoouunndd CCoommmmaannddss above. _c_o_m_-
_p_o_u_n_d_-_c_o_m_m_a_n_d is executed whenever _n_a_m_e is specified as the name
- of a simple command. When in _p_o_s_i_x _m_o_d_e, _n_a_m_e may not be the
- name of one of the POSIX _s_p_e_c_i_a_l _b_u_i_l_t_i_n_s. Any redirections
+ of a simple command. When in _p_o_s_i_x _m_o_d_e, _n_a_m_e may not be the
+ name of one of the POSIX _s_p_e_c_i_a_l _b_u_i_l_t_i_n_s. Any redirections
(see RREEDDIIRREECCTTIIOONN below) specified when a function is defined are
- performed when the function is executed. 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 exe-
- cuted, the exit status of a function is the exit status of the
+ performed when the function is executed. 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 exe-
+ cuted, the exit status of a function is the exit status of the
last command executed in the body. (See FFUUNNCCTTIIOONNSS below.)
CCOOMMMMEENNTTSS
In a non-interactive shell, or an interactive shell in which the iinntteerr--
- aaccttiivvee__ccoommmmeennttss option to the sshhoopptt builtin is enabled (see SSHHEELLLL
- BBUUIILLTTIINN CCOOMMMMAANNDDSS below), a word beginning with ## causes that word and
- all remaining characters on that line to be ignored. An interactive
- shell without the iinntteerraaccttiivvee__ccoommmmeennttss option enabled does not allow
+ aaccttiivvee__ccoommmmeennttss option to the sshhoopptt builtin is enabled (see SSHHEELLLL
+ BBUUIILLTTIINN CCOOMMMMAANNDDSS below), a word beginning with ## causes that word and
+ all remaining characters on that line to be ignored. An interactive
+ shell without the iinntteerraaccttiivvee__ccoommmmeennttss option enabled does not allow
comments. The iinntteerraaccttiivvee__ccoommmmeennttss option is on by default in interac-
tive shells.
QQUUOOTTIINNGG
- _Q_u_o_t_i_n_g is used to remove the special meaning of certain characters or
- words to the shell. Quoting can be used to disable special treatment
+ _Q_u_o_t_i_n_g 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.
- Each of the _m_e_t_a_c_h_a_r_a_c_t_e_r_s listed above under DDEEFFIINNIITTIIOONNSS has special
+ Each of the _m_e_t_a_c_h_a_r_a_c_t_e_r_s listed above under DDEEFFIINNIITTIIOONNSS 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 HHIISS--
+ When the command history expansion facilities are being used (see HHIISS--
TTOORRYY EEXXPPAANNSSIIOONN below), the _h_i_s_t_o_r_y _e_x_p_a_n_s_i_o_n character, usually !!, must
be quoted to prevent history expansion.
- There are three quoting mechanisms: the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r, single
+ There are three quoting mechanisms: the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r, single
quotes, and double quotes.
- A non-quoted backslash (\\) is the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r. It preserves the
+ A non-quoted backslash (\\) is the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r. It preserves the
literal value of the next character that follows, with the exception of
- <newline>. If a \\<newline> pair appears, and the backslash is not
- itself quoted, the \\<newline> is treated as a line continuation (that
+ <newline>. If a \\<newline> pair appears, and the backslash is not
+ itself quoted, the \\<newline> is treated as a line continuation (that
is, it is removed from the input stream and effectively ignored).
- Enclosing characters in single quotes preserves the literal value of
+ Enclosing characters in single quotes 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.
- Enclosing characters in double quotes preserves the literal value of
- all characters within the quotes, with the exception of $$, ``, \\, and,
- when history expansion is enabled, !!. The characters $$ and `` retain
- their special meaning within double quotes. The backslash retains its
- special meaning only when followed by one of the following characters:
- $$, ``, "", \\, or <<nneewwlliinnee>>. A double quote may be quoted within double
+ Enclosing characters in double quotes preserves the literal value of
+ all characters within the quotes, with the exception of $$, ``, \\, and,
+ when history expansion is enabled, !!. The characters $$ and `` retain
+ their special meaning within double quotes. The backslash retains its
+ special meaning only when followed by one of the following characters:
+ $$, ``, "", \\, or <<nneewwlliinnee>>. A double quote may be quoted within double
quotes by preceding it with a backslash. If enabled, history expansion
- will be performed unless an !! appearing in double quotes is escaped
+ will be performed unless an !! appearing in double quotes is escaped
using a backslash. The backslash preceding the !! is not removed.
- The special parameters ** and @@ have special meaning when in double
+ The special parameters ** and @@ have special meaning when in double
quotes (see PPAARRAAMMEETTEERRSS below).
Words of the form $$'_s_t_r_i_n_g' are treated specially. The word expands to
- _s_t_r_i_n_g, with backslash-escaped characters replaced as specified by the
- ANSI C standard. Backslash escape sequences, if present, are decoded
+ _s_t_r_i_n_g, with backslash-escaped characters replaced as specified by the
+ ANSI C standard. Backslash escape sequences, if present, are decoded
as follows:
\\aa alert (bell)
\\bb backspace
@@ -594,335 +599,335 @@ QQUUOOTTIINNGG
\\\\ backslash
\\'' single quote
\\"" double quote
- \\_n_n_n the eight-bit character whose value is the octal value
+ \\_n_n_n the eight-bit character whose value is the octal value
_n_n_n (one to three digits)
- \\xx_H_H the eight-bit character whose value is the hexadecimal
+ \\xx_H_H the eight-bit character whose value is the hexadecimal
value _H_H (one or two hex digits)
- \\uu_H_H_H_H the Unicode (ISO/IEC 10646) character whose value is the
+ \\uu_H_H_H_H the Unicode (ISO/IEC 10646) character whose value is the
hexadecimal value _H_H_H_H (one to four hex digits)
\\UU_H_H_H_H_H_H_H_H
- the Unicode (ISO/IEC 10646) character whose value is the
+ the Unicode (ISO/IEC 10646) character whose value is the
hexadecimal value _H_H_H_H_H_H_H_H (one to eight hex digits)
\\cc_x a control-_x character
- The expanded result is single-quoted, as if the dollar sign had not
+ The expanded result is single-quoted, as if the dollar sign had not
been present.
A double-quoted string preceded by a dollar sign ($$"_s_t_r_i_n_g") will cause
- the string to be translated according to the current locale. If the
- current locale is CC or PPOOSSIIXX, the dollar sign is ignored. If the
+ the string to be translated according to the current locale. If the
+ current locale is CC or PPOOSSIIXX, the dollar sign is ignored. If the
string is translated and replaced, the replacement is double-quoted.
PPAARRAAMMEETTEERRSS
- A _p_a_r_a_m_e_t_e_r is an entity that stores values. It can be a _n_a_m_e, a num-
+ A _p_a_r_a_m_e_t_e_r is an entity that stores values. It can be a _n_a_m_e, a num-
ber, or one of the special characters listed below under SSppeecciiaall PPaarraamm--
- eetteerrss. A _v_a_r_i_a_b_l_e is a parameter denoted by a _n_a_m_e. A variable has a
- _v_a_l_u_e and zero or more _a_t_t_r_i_b_u_t_e_s. Attributes are assigned using the
- ddeeccllaarree builtin command (see ddeeccllaarree below in SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS).
+ eetteerrss. A _v_a_r_i_a_b_l_e is a parameter denoted by a _n_a_m_e. A variable has a
+ _v_a_l_u_e and zero or more _a_t_t_r_i_b_u_t_e_s. Attributes are assigned using the
+ ddeeccllaarree builtin command (see ddeeccllaarree below in SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS).
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
+ a valid value. Once a variable is set, it may be unset only by using
the uunnsseett builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
A _v_a_r_i_a_b_l_e may be assigned to by a statement of the form
_n_a_m_e=[_v_a_l_u_e]
- If _v_a_l_u_e is not given, the variable is assigned the null string. All
- _v_a_l_u_e_s undergo tilde expansion, parameter and variable expansion, com-
- mand substitution, arithmetic expansion, and quote removal (see EEXXPPAANN--
+ If _v_a_l_u_e is not given, the variable is assigned the null string. All
+ _v_a_l_u_e_s undergo tilde expansion, parameter and variable expansion, com-
+ mand substitution, arithmetic expansion, and quote removal (see EEXXPPAANN--
SSIIOONN below). If the variable has its iinntteeggeerr attribute set, then _v_a_l_u_e
is evaluated as an arithmetic expression even if the $((...)) expansion
- is not used (see AArriitthhmmeettiicc EExxppaannssiioonn below). Word splitting is not
- performed, with the exception of ""$$@@"" as explained below under SSppeecciiaall
- PPaarraammeetteerrss. Pathname expansion is not performed. Assignment state-
- ments may also appear as arguments to the aalliiaass, ddeeccllaarree, ttyyppeesseett,
- eexxppoorrtt, rreeaaddoonnllyy, and llooccaall builtin commands. When in _p_o_s_i_x _m_o_d_e,
- these builtins may appear in a command after one or more instances of
+ is not used (see AArriitthhmmeettiicc EExxppaannssiioonn below). Word splitting is not
+ performed, with the exception of ""$$@@"" as explained below under SSppeecciiaall
+ PPaarraammeetteerrss. Pathname expansion is not performed. Assignment state-
+ ments may also appear as arguments to the aalliiaass, ddeeccllaarree, ttyyppeesseett,
+ eexxppoorrtt, rreeaaddoonnllyy, and llooccaall builtin commands. When in _p_o_s_i_x _m_o_d_e,
+ these builtins may appear in a command after one or more instances of
the ccoommmmaanndd builtin and retain these assignment statement properties.
- In the context where an assignment statement is assigning a value to a
+ In the context where an assignment statement is assigning a value to a
shell variable or array index, the += operator can be used to append to
or add to the variable's previous value. When += is applied to a vari-
- able for which the _i_n_t_e_g_e_r attribute has been set, _v_a_l_u_e is evaluated
- as an arithmetic expression and added to the variable's current value,
+ able for which the _i_n_t_e_g_e_r attribute has been set, _v_a_l_u_e is evaluated
+ as an arithmetic expression and added to the variable's current value,
which is also evaluated. When += is applied to an array variable using
- compound assignment (see AArrrraayyss below), the variable's value is not
+ compound assignment (see AArrrraayyss below), the variable's value is not
unset (as it is when using =), and new values are appended to the array
- beginning at one greater than the array's maximum index (for indexed
+ beginning at one greater than the array's maximum index (for indexed
arrays) or added as additional key-value pairs in an associative array.
- When applied to a string-valued variable, _v_a_l_u_e is expanded and
+ When applied to a string-valued variable, _v_a_l_u_e is expanded and
appended to the variable's value.
PPoossiittiioonnaall PPaarraammeetteerrss
- A _p_o_s_i_t_i_o_n_a_l _p_a_r_a_m_e_t_e_r is a parameter denoted by one or more digits,
+ A _p_o_s_i_t_i_o_n_a_l _p_a_r_a_m_e_t_e_r is a parameter denoted by one or more digits,
other than the single digit 0. Positional parameters are assigned from
- the shell's arguments when it is invoked, and may be reassigned using
- the sseett builtin command. Positional parameters may not be assigned to
- with assignment statements. The positional parameters are temporarily
+ the shell's arguments when it is invoked, and may be reassigned using
+ the sseett builtin command. Positional parameters may not be assigned to
+ with assignment statements. The positional parameters are temporarily
replaced when a shell function is executed (see FFUUNNCCTTIIOONNSS below).
- When a positional parameter consisting of more than a single digit is
+ When a positional parameter consisting of more than a single digit is
expanded, it must be enclosed in braces (see EEXXPPAANNSSIIOONN below).
SSppeecciiaall PPaarraammeetteerrss
- The shell treats several parameters specially. These parameters may
+ The shell treats several parameters specially. These parameters may
only be referenced; assignment to them is not allowed.
- ** Expands to the positional parameters, starting from one. When
- the expansion occurs within double quotes, it expands to a sin-
+ ** Expands to the positional parameters, starting from one. When
+ the expansion occurs within double quotes, it expands to a sin-
gle word with the value of each parameter separated by the first
character of the IIFFSS special variable. That is, "$$**" is equiva-
lent to "$$11_c$$22_c......", where _c is the first character of the value
- of the IIFFSS variable. If IIFFSS is unset, the parameters are sepa-
- rated by spaces. If IIFFSS is null, the parameters are joined
+ of the IIFFSS variable. If IIFFSS is unset, the parameters are sepa-
+ rated by spaces. If IIFFSS is null, the parameters are joined
without intervening separators.
- @@ Expands to the positional parameters, starting from one. When
+ @@ Expands to the positional parameters, starting from one. When
the expansion occurs within double quotes, each parameter
expands to a separate word. That is, "$$@@" is equivalent to "$$11"
- "$$22" ... If the double-quoted expansion occurs within a word,
- the expansion of the first parameter is joined with the begin-
- ning 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, "$$@@" and $$@@ expand to
+ "$$22" ... If the double-quoted expansion occurs within a word,
+ the expansion of the first parameter is joined with the begin-
+ ning part of the original word, and the expansion of the last
+ parameter is joined with the last part of the original word.
+ When there are no positional parameters, "$$@@" and $$@@ expand to
nothing (i.e., they are removed).
## Expands to the number of positional parameters in decimal.
- ?? Expands to the exit status of the most recently executed fore-
+ ?? Expands to the exit status of the most recently executed fore-
ground pipeline.
- -- Expands to the current option flags as specified upon invoca-
- tion, by the sseett builtin command, or those set by the shell
+ -- Expands to the current option flags as specified upon invoca-
+ tion, by the sseett builtin command, or those set by the shell
itself (such as the --ii option).
- $$ Expands to the process ID of the shell. In a () subshell, it
- expands to the process ID of the current shell, not the sub-
+ $$ Expands to the process ID of the shell. In a () subshell, it
+ expands to the process ID of the current shell, not the sub-
shell.
- !! Expands to the process ID of the most recently executed back-
+ !! Expands to the process ID of the most recently executed back-
ground (asynchronous) command.
- 00 Expands to the name of the shell or shell script. This is set
+ 00 Expands to the name of the shell or shell script. This is set
at shell initialization. If bbaasshh is invoked with a file of com-
- mands, $$00 is set to the name of that file. If bbaasshh is started
- with the --cc option, then $$00 is set to the first argument after
- the string to be executed, if one is present. Otherwise, it is
- set to the filename used to invoke bbaasshh, as given by argument
+ mands, $$00 is set to the name of that file. If bbaasshh is started
+ with the --cc option, then $$00 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 bbaasshh, as given by argument
zero.
- __ At shell startup, set to the absolute pathname used to invoke
- the shell or shell script being executed as passed in the envi-
- ronment 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
+ __ At shell startup, set to the absolute pathname used to invoke
+ the shell or shell script being executed as passed in the envi-
+ ronment 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 check-
- ing mail, this parameter holds the name of the mail file cur-
+ ing mail, this parameter holds the name of the mail file cur-
rently being checked.
SShheellll VVaarriiaabblleess
The following variables are set by the shell:
- BBAASSHH Expands to the full filename used to invoke this instance of
+ BBAASSHH Expands to the full filename used to invoke this instance of
bbaasshh.
BBAASSHHOOPPTTSS
- A colon-separated list of enabled shell options. Each word in
- the list is a valid argument for the --ss option to the sshhoopptt
+ A colon-separated list of enabled shell options. Each word in
+ the list is a valid argument for the --ss option to the sshhoopptt
builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). The options
- appearing in BBAASSHHOOPPTTSS are those reported as _o_n by sshhoopptt. If
- this variable is in the environment when bbaasshh starts up, each
- shell option in the list will be enabled before reading any
+ appearing in BBAASSHHOOPPTTSS are those reported as _o_n by sshhoopptt. If
+ this variable is in the environment when bbaasshh starts up, each
+ shell option in the list will be enabled before reading any
startup files. This variable is read-only.
BBAASSHHPPIIDD
- Expands to the process ID of the current bbaasshh process. This
- differs from $$$$ under certain circumstances, such as subshells
+ Expands to the process ID of the current bbaasshh process. This
+ differs from $$$$ under certain circumstances, such as subshells
that do not require bbaasshh to be re-initialized.
BBAASSHH__AALLIIAASSEESS
- An associative array variable whose members correspond to the
- internal list of aliases as maintained by the aalliiaass builtin.
+ An associative array variable whose members correspond to the
+ internal list of aliases as maintained by the aalliiaass builtin.
Elements added to this array appear in the alias list; unsetting
- array elements cause aliases to be removed from the alias list.
+ array elements cause aliases to be removed from the alias list.
BBAASSHH__AARRGGCC
- An array variable whose values are the number of parameters in
+ An array variable whose values are the number of parameters in
each frame of the current bbaasshh execution call stack. The number
- of parameters to the current subroutine (shell function or
- script executed with .. or ssoouurrccee) is at the top of the stack.
- When a subroutine is executed, the number of parameters passed
+ of parameters to the current subroutine (shell function or
+ script executed with .. or ssoouurrccee) is at the top of the stack.
+ When a subroutine is executed, the number of parameters passed
is pushed onto BBAASSHH__AARRGGCC. The shell sets BBAASSHH__AARRGGCC only when in
- extended debugging mode (see the description of the eexxttddeebbuugg
+ extended debugging mode (see the description of the eexxttddeebbuugg
option to the sshhoopptt builtin below)
BBAASSHH__AARRGGVV
- An array variable containing all of the parameters in the cur-
+ An array variable containing all of the parameters in the cur-
rent bbaasshh execution call stack. The final parameter of the last
- subroutine call is at the top of the stack; the first parameter
+ subroutine call is at the top of the stack; the first parameter
of the initial call is at the bottom. When a subroutine is exe-
- cuted, the parameters supplied are pushed onto BBAASSHH__AARRGGVV. The
- shell sets BBAASSHH__AARRGGVV only when in extended debugging mode (see
- the description of the eexxttddeebbuugg option to the sshhoopptt builtin
+ cuted, the parameters supplied are pushed onto BBAASSHH__AARRGGVV. The
+ shell sets BBAASSHH__AARRGGVV only when in extended debugging mode (see
+ the description of the eexxttddeebbuugg option to the sshhoopptt builtin
below)
BBAASSHH__CCMMDDSS
- An associative array variable whose members correspond to the
- internal hash table of commands as maintained by the hhaasshh
+ An associative array variable whose members correspond to the
+ internal hash table of commands as maintained by the hhaasshh
builtin. Elements added to this array appear in the hash table;
- unsetting array elements cause commands to be removed from the
+ unsetting array elements cause commands to be removed from the
hash table.
BBAASSHH__CCOOMMMMAANNDD
- The command currently being executed or about to be executed,
+ 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
+ in which case it is the command executing at the time of the
trap.
BBAASSHH__EEXXEECCUUTTIIOONN__SSTTRRIINNGG
The command argument to the --cc invocation option.
BBAASSHH__LLIINNEENNOO
- An array variable whose members are the line numbers in source
- files where each corresponding member of FFUUNNCCNNAAMMEE was invoked.
+ An array variable whose members are the line numbers in source
+ files where each corresponding member of FFUUNNCCNNAAMMEE was invoked.
$${{BBAASSHH__LLIINNEENNOO[[_$_i]]}} is the line number in the source file
($${{BBAASSHH__SSOOUURRCCEE[[_$_i_+_1]]}}) where $${{FFUUNNCCNNAAMMEE[[_$_i]]}} was called (or
- $${{BBAASSHH__LLIINNEENNOO[[_$_i_-_1]]}} if referenced within another shell func-
+ $${{BBAASSHH__LLIINNEENNOO[[_$_i_-_1]]}} if referenced within another shell func-
tion). Use LLIINNEENNOO to obtain the current line number.
BBAASSHH__RREEMMAATTCCHH
- An array variable whose members are assigned by the ==~~ binary
- operator to the [[[[ conditional command. The element with index
- 0 is the portion of the string matching the entire regular
- expression. The element with index _n is the portion of the
+ An array variable whose members are assigned by the ==~~ binary
+ operator to the [[[[ conditional command. The element with index
+ 0 is the portion of the string matching the entire regular
+ expression. The element with index _n is the portion of the
string matching the _nth parenthesized subexpression. This vari-
able is read-only.
BBAASSHH__SSOOUURRCCEE
- An array variable whose members are the source filenames where
- the corresponding shell function names in the FFUUNNCCNNAAMMEE array
- variable are defined. The shell function $${{FFUUNNCCNNAAMMEE[[_$_i]]}} is
- defined in the file $${{BBAASSHH__SSOOUURRCCEE[[_$_i]]}} and called from
+ An array variable whose members are the source filenames where
+ the corresponding shell function names in the FFUUNNCCNNAAMMEE array
+ variable are defined. The shell function $${{FFUUNNCCNNAAMMEE[[_$_i]]}} is
+ defined in the file $${{BBAASSHH__SSOOUURRCCEE[[_$_i]]}} and called from
$${{BBAASSHH__SSOOUURRCCEE[[_$_i_+_1]]}}.
BBAASSHH__SSUUBBSSHHEELLLL
- Incremented by one within each subshell or subshell environment
- when the shell begins executing in that environment. The ini-
+ Incremented by one within each subshell or subshell environment
+ when the shell begins executing in that environment. The ini-
tial value is 0.
BBAASSHH__VVEERRSSIINNFFOO
A readonly array variable whose members hold version information
- for this instance of bbaasshh. The values assigned to the array
+ for this instance of bbaasshh. The values assigned to the array
members are as follows:
- BBAASSHH__VVEERRSSIINNFFOO[[0]] The major version number (the _r_e_l_e_a_s_e).
- BBAASSHH__VVEERRSSIINNFFOO[[1]] The minor version number (the _v_e_r_s_i_o_n).
+ BBAASSHH__VVEERRSSIINNFFOO[[0]] The major version number (the _r_e_l_e_a_s_e).
+ BBAASSHH__VVEERRSSIINNFFOO[[1]] The minor version number (the _v_e_r_s_i_o_n).
BBAASSHH__VVEERRSSIINNFFOO[[2]] The patch level.
BBAASSHH__VVEERRSSIINNFFOO[[3]] The build version.
BBAASSHH__VVEERRSSIINNFFOO[[4]] The release status (e.g., _b_e_t_a_1).
BBAASSHH__VVEERRSSIINNFFOO[[5]] The value of MMAACCHHTTYYPPEE.
BBAASSHH__VVEERRSSIIOONN
- Expands to a string describing the version of this instance of
+ Expands to a string describing the version of this instance of
bbaasshh.
CCOOMMPP__CCWWOORRDD
- An index into $${{CCOOMMPP__WWOORRDDSS}} of the word containing the current
+ An index into $${{CCOOMMPP__WWOORRDDSS}} of the word containing the current
cursor position. This variable is available only in shell func-
- tions invoked by the programmable completion facilities (see
+ tions invoked by the programmable completion facilities (see
PPrrooggrraammmmaabbllee CCoommpplleettiioonn below).
CCOOMMPP__KKEEYY
The key (or final key of a key sequence) used to invoke the cur-
rent completion function.
CCOOMMPP__LLIINNEE
- The current command line. This variable is available only in
- shell functions and external commands invoked by the pro-
- grammable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn
+ The current command line. This variable is available only in
+ shell functions and external commands invoked by the pro-
+ grammable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn
below).
CCOOMMPP__PPOOIINNTT
- The index of the current cursor position relative to the begin-
- ning of the current command. If the current cursor position is
+ The index of the current cursor position relative to the begin-
+ ning of the current command. If the current cursor position is
at the end of the current command, the value of this variable is
- equal to $${{##CCOOMMPP__LLIINNEE}}. This variable is available only in
- shell functions and external commands invoked by the pro-
- grammable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn
+ equal to $${{##CCOOMMPP__LLIINNEE}}. This variable is available only in
+ shell functions and external commands invoked by the pro-
+ grammable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn
below).
CCOOMMPP__TTYYPPEE
- Set to an integer value corresponding to the type of completion
- attempted that caused a completion function to be called: _T_A_B,
- for normal completion, _?, for listing completions after succes-
- sive tabs, _!, for listing alternatives on partial word comple-
- tion, _@, to list completions if the word is not unmodified, or
- _%, for menu completion. This variable is available only in
- shell functions and external commands invoked by the pro-
- grammable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn
+ Set to an integer value corresponding to the type of completion
+ attempted that caused a completion function to be called: _T_A_B,
+ for normal completion, _?, for listing completions after succes-
+ sive tabs, _!, for listing alternatives on partial word comple-
+ tion, _@, to list completions if the word is not unmodified, or
+ _%, for menu completion. This variable is available only in
+ shell functions and external commands invoked by the pro-
+ grammable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn
below).
CCOOMMPP__WWOORRDDBBRREEAAKKSS
- The set of characters that the rreeaaddlliinnee library treats as word
- separators when performing word completion. If CCOOMMPP__WWOORRDDBBRREEAAKKSS
- is unset, it loses its special properties, even if it is subse-
+ The set of characters that the rreeaaddlliinnee library treats as word
+ separators when performing word completion. If CCOOMMPP__WWOORRDDBBRREEAAKKSS
+ is unset, it loses its special properties, even if it is subse-
quently reset.
CCOOMMPP__WWOORRDDSS
- An array variable (see AArrrraayyss below) consisting of the individ-
- ual words in the current command line. The line is split into
- words as rreeaaddlliinnee would split it, using CCOOMMPP__WWOORRDDBBRREEAAKKSS as
+ An array variable (see AArrrraayyss below) consisting of the individ-
+ ual words in the current command line. The line is split into
+ words as rreeaaddlliinnee would split it, using CCOOMMPP__WWOORRDDBBRREEAAKKSS as
described above. This variable is available only in shell func-
- tions invoked by the programmable completion facilities (see
+ tions invoked by the programmable completion facilities (see
PPrrooggrraammmmaabbllee CCoommpplleettiioonn below).
- CCOOPPRROOCC An array variable (see AArrrraayyss below) created to hold the file
- descriptors for output from and input to an unnamed coprocess
+ CCOOPPRROOCC An array variable (see AArrrraayyss below) created to hold the file
+ descriptors for output from and input to an unnamed coprocess
(see CCoopprroocceesssseess above).
DDIIRRSSTTAACCKK
An array variable (see AArrrraayyss below) containing the current con-
- tents of the directory stack. Directories appear in the stack
- in the order they are displayed by the ddiirrss builtin. Assigning
+ tents of the directory stack. Directories appear in the stack
+ in the order they are displayed by the ddiirrss builtin. Assigning
to members of this array variable may be used to modify directo-
- ries already in the stack, but the ppuusshhdd and ppooppdd builtins must
+ ries already in the stack, but the ppuusshhdd and ppooppdd builtins must
be used to add and remove directories. Assignment to this vari-
- able will not change the current directory. If DDIIRRSSTTAACCKK is
- unset, it loses its special properties, even if it is subse-
+ able will not change the current directory. If DDIIRRSSTTAACCKK is
+ unset, it loses its special properties, even if it is subse-
quently reset.
- EEUUIIDD Expands to the effective user ID of the current user, initial-
+ EEUUIIDD Expands to the effective user ID of the current user, initial-
ized at shell startup. This variable is readonly.
FFUUNNCCNNAAMMEE
- An array variable containing the names of all shell functions
+ 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 bot-
- tom-most element (the one with the highest index) is "main".
- This variable exists only when a shell function is executing.
- Assignments to FFUUNNCCNNAAMMEE have no effect and return an error sta-
- tus. If FFUUNNCCNNAAMMEE is unset, it loses its special properties,
+ tom-most element (the one with the highest index) is "main".
+ This variable exists only when a shell function is executing.
+ Assignments to FFUUNNCCNNAAMMEE have no effect and return an error sta-
+ tus. If FFUUNNCCNNAAMMEE is unset, it loses its special properties,
even if it is subsequently reset.
- This variable can be used with BBAASSHH__LLIINNEENNOO and BBAASSHH__SSOOUURRCCEE.
- Each element of FFUUNNCCNNAAMMEE has corresponding elements in
- BBAASSHH__LLIINNEENNOO and BBAASSHH__SSOOUURRCCEE to describe the call stack. For
- instance, $${{FFUUNNCCNNAAMMEE[[_$_i]]}} was called from the file
- $${{BBAASSHH__SSOOUURRCCEE[[_$_i_+_1]]}} at line number $${{BBAASSHH__LLIINNEENNOO[[_$_i]]}}. The
+ This variable can be used with BBAASSHH__LLIINNEENNOO and BBAASSHH__SSOOUURRCCEE.
+ Each element of FFUUNNCCNNAAMMEE has corresponding elements in
+ BBAASSHH__LLIINNEENNOO and BBAASSHH__SSOOUURRCCEE to describe the call stack. For
+ instance, $${{FFUUNNCCNNAAMMEE[[_$_i]]}} was called from the file
+ $${{BBAASSHH__SSOOUURRCCEE[[_$_i_+_1]]}} at line number $${{BBAASSHH__LLIINNEENNOO[[_$_i]]}}. The
ccaalllleerr builtin displays the current call stack using this infor-
mation.
- GGRROOUUPPSS An array variable containing the list of groups of which the
- current user is a member. Assignments to GGRROOUUPPSS have no effect
- and return an error status. If GGRROOUUPPSS is unset, it loses its
+ GGRROOUUPPSS An array variable containing the list of groups of which the
+ current user is a member. Assignments to GGRROOUUPPSS have no effect
+ and return an error status. If GGRROOUUPPSS is unset, it loses its
special properties, even if it is subsequently reset.
HHIISSTTCCMMDD
The history number, or index in the history list, of the current
- command. If HHIISSTTCCMMDD is unset, it loses its special properties,
+ command. If HHIISSTTCCMMDD is unset, it loses its special properties,
even if it is subsequently reset.
HHOOSSTTNNAAMMEE
Automatically set to the name of the current host.
HHOOSSTTTTYYPPEE
- Automatically set to a string that uniquely describes the type
- of machine on which bbaasshh is executing. The default is system-
+ Automatically set to a string that uniquely describes the type
+ of machine on which bbaasshh is executing. The default is system-
dependent.
- LLIINNEENNOO Each time this parameter is referenced, the shell substitutes a
- decimal number representing the current sequential line number
- (starting with 1) within a script or function. When not in a
- script or function, the value substituted is not guaranteed to
+ LLIINNEENNOO Each time this parameter is referenced, the shell substitutes a
+ decimal number representing the current sequential line number
+ (starting with 1) within a script or function. When not in a
+ script or function, the value substituted is not guaranteed to
be meaningful. If LLIINNEENNOO is unset, it loses its special proper-
ties, even if it is subsequently reset.
MMAACCHHTTYYPPEE
- Automatically set to a string that fully describes the system
- type on which bbaasshh is executing, in the standard GNU _c_p_u_-_c_o_m_-
+ Automatically set to a string that fully describes the system
+ type on which bbaasshh is executing, in the standard GNU _c_p_u_-_c_o_m_-
_p_a_n_y_-_s_y_s_t_e_m format. The default is system-dependent.
MMAAPPFFIILLEE
- An array variable (see AArrrraayyss below) created to hold the text
+ An array variable (see AArrrraayyss below) created to hold the text
read by the mmaappffiillee builtin when no variable name is supplied.
OOLLDDPPWWDD The previous working directory as set by the ccdd command.
- OOPPTTAARRGG The value of the last option argument processed by the ggeettooppttss
+ OOPPTTAARRGG The value of the last option argument processed by the ggeettooppttss
builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
- OOPPTTIINNDD The index of the next argument to be processed by the ggeettooppttss
+ OOPPTTIINNDD The index of the next argument to be processed by the ggeettooppttss
builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
- OOSSTTYYPPEE Automatically set to a string that describes the operating sys-
- tem on which bbaasshh is executing. The default is system-depen-
+ OOSSTTYYPPEE Automatically set to a string that describes the operating sys-
+ tem on which bbaasshh is executing. The default is system-depen-
dent.
PPIIPPEESSTTAATTUUSS
- An array variable (see AArrrraayyss below) containing a list of exit
- status values from the processes in the most-recently-executed
+ An array variable (see AArrrraayyss below) containing a list of exit
+ status values from the processes in the most-recently-executed
foreground pipeline (which may contain only a single command).
- PPPPIIDD The process ID of the shell's parent. This variable is read-
+ PPPPIIDD The process ID of the shell's parent. This variable is read-
only.
PPWWDD The current working directory as set by the ccdd command.
RRAANNDDOOMM Each time this parameter is referenced, a random integer between
0 and 32767 is generated. The sequence of random numbers may be
initialized by assigning a value to RRAANNDDOOMM. If RRAANNDDOOMM is unset,
- it loses its special properties, even if it is subsequently
+ it loses its special properties, even if it is subsequently
reset.
RREEAADDLLIINNEE__LLIINNEE
The contents of the rreeaaddlliinnee line buffer, for use with "bind -x"
@@ -930,58 +935,59 @@ PPAARRAAMMEETTEERRSS
RREEAADDLLIINNEE__PPOOIINNTT
The position of the insertion point in the rreeaaddlliinnee line buffer,
for use with "bind -x" (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
- RREEPPLLYY Set to the line of input read by the rreeaadd builtin command when
+ RREEPPLLYY Set to the line of input read by the rreeaadd builtin command when
no arguments are supplied.
SSEECCOONNDDSS
- Each time this parameter is referenced, the number of seconds
- since shell invocation is returned. If a value is assigned to
- SSEECCOONNDDSS, the value returned upon subsequent references is the
- number of seconds since the assignment plus the value assigned.
+ Each time this parameter is referenced, the number of seconds
+ since shell invocation is returned. If a value is assigned to
+ SSEECCOONNDDSS, the value returned upon subsequent references is the
+ number of seconds since the assignment plus the value assigned.
If SSEECCOONNDDSS is unset, it loses its special properties, even if it
is subsequently reset.
SSHHEELLLLOOPPTTSS
- A colon-separated list of enabled shell options. Each word in
- the list is a valid argument for the --oo option to the sseett
+ A colon-separated list of enabled shell options. Each word in
+ the list is a valid argument for the --oo option to the sseett
builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). The options
- appearing in SSHHEELLLLOOPPTTSS are those reported as _o_n by sseett --oo. If
- this variable is in the environment when bbaasshh starts up, each
- shell option in the list will be enabled before reading any
+ appearing in SSHHEELLLLOOPPTTSS are those reported as _o_n by sseett --oo. If
+ this variable is in the environment when bbaasshh starts up, each
+ shell option in the list will be enabled before reading any
startup files. This variable is read-only.
SSHHLLVVLL Incremented by one each time an instance of bbaasshh is started.
UUIIDD Expands to the user ID of the current user, initialized at shell
startup. This variable is readonly.
- The following variables are used by the shell. In some cases, bbaasshh
+ The following variables are used by the shell. In some cases, bbaasshh
assigns a default value to a variable; these cases are noted below.
BBAASSHH__EENNVV
- If this parameter is set when bbaasshh is executing a shell script,
- its value is interpreted as a filename containing commands to
+ If this parameter is set when bbaasshh is executing a shell script,
+ its value is interpreted as a filename containing commands to
initialize the shell, as in _~_/_._b_a_s_h_r_c. The value of BBAASSHH__EENNVV is
- subjected to parameter expansion, command substitution, and
- arithmetic expansion before being interpreted as a filename.
+ subjected to parameter expansion, command substitution, and
+ arithmetic expansion before being interpreted as a filename.
PPAATTHH is not used to search for the resultant filename.
BBAASSHH__XXTTRRAACCEEFFDD
- If set to an integer corresponding to a valid file descriptor,
- bbaasshh will write the trace output generated when _s_e_t _-_x is
- enabled to that file descriptor. The file descriptor is closed
- when BBAASSHH__XXTTRRAACCEEFFDD is unset or assigned a new value. Unsetting
- BBAASSHH__XXTTRRAACCEEFFDD or assigning it the empty string causes the trace
- output to be sent to the standard error. Note that setting
+ If set to an integer corresponding to a valid file descriptor,
+ bbaasshh will write the trace output generated when _s_e_t _-_x is
+ enabled to that file descriptor. The file descriptor is closed
+ when BBAASSHH__XXTTRRAACCEEFFDD is unset or assigned a new value. Unsetting
+ BBAASSHH__XXTTRRAACCEEFFDD or assigning it the empty string causes the trace
+ output to be sent to the standard error. Note that setting
BBAASSHH__XXTTRRAACCEEFFDD to 2 (the standard error file descriptor) and then
unsetting it will result in the standard error being closed.
- CCDDPPAATTHH The search path for the ccdd command. This is a colon-separated
- list of directories in which the shell looks for destination
- directories specified by the ccdd command. A sample value is
+ CCDDPPAATTHH The search path for the ccdd command. This is a colon-separated
+ list of directories in which the shell looks for destination
+ directories specified by the ccdd command. A sample value is
".:~:/usr".
CCOOLLUUMMNNSS
- Used by the sseelleecctt compound command to determine the terminal
- width when printing selection lists. Automatically set in an
+ Used by the sseelleecctt compound command to determine the terminal
+ width when printing selection lists. Automatically set in an
interactive shell upon receipt of a SSIIGGWWIINNCCHH.
CCOOMMPPRREEPPLLYY
An array variable from which bbaasshh reads the possible completions
- generated by a shell function invoked by the programmable com-
- pletion facility (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn below).
+ generated by a shell function invoked by the programmable com-
+ pletion facility (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn below). Each
+ array element contains one possible completion.
EEMMAACCSS If bbaasshh finds this variable in the environment when the shell
starts with value "t", it assumes that the shell is running in
an Emacs shell buffer and disables line editing.
@@ -1025,151 +1031,158 @@ PPAARRAAMMEETTEERRSS
HHIISSTTFFIILLEESSIIZZEE
The maximum number of lines contained in the history file. When
this variable is assigned a value, the history file is trun-
- cated, if necessary, by removing the oldest entries, to contain
- no more than that number of lines. The default value is 500.
- The history file is also truncated to this size after writing it
- when an interactive shell exits.
+ cated, if necessary, to contain no more than that number of
+ lines by removing the oldest entries. The history file is also
+ truncated to this size after writing it when an interactive
+ shell exits. If the value is 0, the history file is truncated
+ to zero size. Non-numeric values and numeric values less than
+ zero inhibit truncation. The shell sets the default value to
+ the value of HHIISSTTSSIIZZEE after reading any startup files.
HHIISSTTIIGGNNOORREE
- 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 com-
- plete line (no implicit `**' is appended). Each pattern is
- tested against the line after the checks specified by HHIISSTTCCOONN--
- TTRROOLL are applied. In addition to the normal shell pattern
+ 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 com-
+ plete line (no implicit `**' is appended). Each pattern is
+ tested against the line after the checks specified by HHIISSTTCCOONN--
+ TTRROOLL are applied. In addition to the normal shell pattern
matching characters, `&&' matches the previous history line. `&&'
- may be escaped using a backslash; the backslash is removed
+ 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 HHIISSTTIIGGNNOORREE.
HHIISSTTSSIIZZEE
- The number of commands to remember in the command history (see
- HHIISSTTOORRYY below). The default value is 500.
+ The number of commands to remember in the command history (see
+ HHIISSTTOORRYY below). If the value is 0, commands are not saved in
+ the history list. Numeric values less than zero result in every
+ command being saved on the history list (there is no limit).
+ The shell sets the default value to 500 after reading any
+ startup files.
HHIISSTTTTIIMMEEFFOORRMMAATT
- If this variable is set and not null, its value is used as a
+ If this variable is set and not null, its value is used as a
format string for _s_t_r_f_t_i_m_e(3) to print the time stamp associated
- with each history entry displayed by the hhiissttoorryy builtin. If
- this variable is set, time stamps are written to the history
- file so they may be preserved across shell sessions. This uses
- the history comment character to distinguish timestamps from
+ with each history entry displayed by the hhiissttoorryy builtin. If
+ this variable is set, time stamps are written to the history
+ file so they may be preserved across shell sessions. This uses
+ the history comment character to distinguish timestamps from
other history lines.
HHOOMMEE The home directory of the current user; the default argument for
the ccdd builtin command. The value of this variable is also used
when performing tilde expansion.
HHOOSSTTFFIILLEE
- Contains the name of a file in the same format as _/_e_t_c_/_h_o_s_t_s
+ Contains the name of a file in the same format as _/_e_t_c_/_h_o_s_t_s
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, bbaasshh adds the contents of
- the new file to the existing list. If HHOOSSTTFFIILLEE is set, but has
- no value, or does not name a readable file, bbaasshh attempts to
- read _/_e_t_c_/_h_o_s_t_s to obtain the list of possible hostname comple-
+ 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, bbaasshh adds the contents of
+ the new file to the existing list. If HHOOSSTTFFIILLEE is set, but has
+ no value, or does not name a readable file, bbaasshh attempts to
+ read _/_e_t_c_/_h_o_s_t_s to obtain the list of possible hostname comple-
tions. When HHOOSSTTFFIILLEE is unset, the hostname list is cleared.
- IIFFSS The _I_n_t_e_r_n_a_l _F_i_e_l_d _S_e_p_a_r_a_t_o_r that is used for word splitting
- after expansion and to split lines into words with the rreeaadd
+ IIFFSS The _I_n_t_e_r_n_a_l _F_i_e_l_d _S_e_p_a_r_a_t_o_r that is used for word splitting
+ after expansion and to split lines into words with the rreeaadd
builtin command. The default value is ``<space><tab><new-
line>''.
IIGGNNOORREEEEOOFF
Controls the action of an interactive shell on receipt of an EEOOFF
character as the sole input. If set, the value is the number of
- consecutive EEOOFF characters which must be typed as the first
- characters on an input line before bbaasshh exits. If the variable
- exists but does not have a numeric value, or has no value, the
- default value is 10. If it does not exist, EEOOFF signifies the
+ consecutive EEOOFF characters which must be typed as the first
+ characters on an input line before bbaasshh exits. If the variable
+ exists but does not have a numeric value, or has no value, the
+ default value is 10. If it does not exist, EEOOFF signifies the
end of input to the shell.
IINNPPUUTTRRCC
- The filename for the rreeaaddlliinnee startup file, overriding the
+ The filename for the rreeaaddlliinnee startup file, overriding the
default of _~_/_._i_n_p_u_t_r_c (see RREEAADDLLIINNEE below).
- LLAANNGG Used to determine the locale category for any category not
+ LLAANNGG Used to determine the locale category for any category not
specifically selected with a variable starting with LLCC__.
- LLCC__AALLLL This variable overrides the value of LLAANNGG and any other LLCC__
+ LLCC__AALLLL This variable overrides the value of LLAANNGG and any other LLCC__
variable specifying a locale category.
LLCC__CCOOLLLLAATTEE
- This variable determines the collation order used when sorting
- the results of pathname expansion, and determines the behavior
- of range expressions, equivalence classes, and collating
+ This variable determines the collation order used when sorting
+ the results of pathname expansion, and determines the behavior
+ of range expressions, equivalence classes, and collating
sequences within pathname expansion and pattern matching.
LLCC__CCTTYYPPEE
- This variable determines the interpretation of characters and
- the behavior of character classes within pathname expansion and
+ This variable determines the interpretation of characters and
+ the behavior of character classes within pathname expansion and
pattern matching.
LLCC__MMEESSSSAAGGEESS
- This variable determines the locale used to translate double-
+ This variable determines the locale used to translate double-
quoted strings preceded by a $$.
LLCC__NNUUMMEERRIICC
- This variable determines the locale category used for number
+ This variable determines the locale category used for number
formatting.
- LLIINNEESS Used by the sseelleecctt compound command to determine the column
- length for printing selection lists. Automatically set by an
+ LLIINNEESS Used by the sseelleecctt compound command to determine the column
+ length for printing selection lists. Automatically set by an
interactive shell upon receipt of a SSIIGGWWIINNCCHH.
- MMAAIILL If this parameter is set to a file or directory name and the
- MMAAIILLPPAATTHH variable is not set, bbaasshh informs the user of the
- arrival of mail in the specified file or Maildir-format direc-
+ MMAAIILL If this parameter is set to a file or directory name and the
+ MMAAIILLPPAATTHH variable is not set, bbaasshh informs the user of the
+ arrival of mail in the specified file or Maildir-format direc-
tory.
MMAAIILLCCHHEECCKK
- Specifies how often (in seconds) bbaasshh checks for mail. 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
+ Specifies how often (in seconds) bbaasshh checks for mail. 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.
MMAAIILLPPAATTHH
A colon-separated list of filenames to be checked for mail. The
message to be printed when mail arrives in a particular file may
- be specified by separating the filename from the message with a
- `?'. When used in the text of the message, $$__ expands to the
+ be specified by separating the filename from the message with a
+ `?'. When used in the text of the message, $$__ expands to the
name of the current mailfile. Example:
MMAAIILLPPAATTHH='/var/mail/bfox?"You have mail":~/shell-mail?"$_ has
mail!"'
- BBaasshh supplies a default value for this variable, but the loca-
- tion of the user mail files that it uses is system dependent
+ BBaasshh supplies a default value for this variable, but the loca-
+ tion of the user mail files that it uses is system dependent
(e.g., /var/mail/$$UUSSEERR).
OOPPTTEERRRR If set to the value 1, bbaasshh displays error messages generated by
- the ggeettooppttss builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
- OOPPTTEERRRR is initialized to 1 each time the shell is invoked or a
+ the ggeettooppttss builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
+ OOPPTTEERRRR is initialized to 1 each time the shell is invoked or a
shell script is executed.
- PPAATTHH The search path for commands. It is a colon-separated list of
- directories in which the shell looks for commands (see CCOOMMMMAANNDD
- EEXXEECCUUTTIIOONN below). A zero-length (null) directory name in the
+ PPAATTHH The search path for commands. It is a colon-separated list of
+ directories in which the shell looks for commands (see CCOOMMMMAANNDD
+ EEXXEECCUUTTIIOONN below). A zero-length (null) directory name in the
value of PPAATTHH indicates the current directory. A null directory
- name may appear as two adjacent colons, or as an initial or
- trailing colon. The default path is system-dependent, and is
- set by the administrator who installs bbaasshh. A common value is
+ name may appear as two adjacent colons, or as an initial or
+ trailing colon. The default path is system-dependent, and is
+ set by the administrator who installs bbaasshh. A common value is
``/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin''.
PPOOSSIIXXLLYY__CCOORRRREECCTT
- If this variable is in the environment when bbaasshh starts, the
- shell enters _p_o_s_i_x _m_o_d_e before reading the startup files, as if
- the ----ppoossiixx invocation option had been supplied. If it is set
- while the shell is running, bbaasshh enables _p_o_s_i_x _m_o_d_e, as if the
+ If this variable is in the environment when bbaasshh starts, the
+ shell enters _p_o_s_i_x _m_o_d_e before reading the startup files, as if
+ the ----ppoossiixx invocation option had been supplied. If it is set
+ while the shell is running, bbaasshh enables _p_o_s_i_x _m_o_d_e, as if the
command _s_e_t _-_o _p_o_s_i_x had been executed.
PPRROOMMPPTT__CCOOMMMMAANNDD
If set, the value is executed as a command prior to issuing each
primary prompt.
PPRROOMMPPTT__DDIIRRTTRRIIMM
- If set to a number greater than zero, the value is used as the
+ If set to a number greater than zero, the value is used as the
number of trailing directory components to retain when expanding
- the \\ww and \\WW prompt string escapes (see PPRROOMMPPTTIINNGG below).
+ the \\ww and \\WW prompt string escapes (see PPRROOMMPPTTIINNGG below).
Characters removed are replaced with an ellipsis.
- PPSS11 The value of this parameter is expanded (see PPRROOMMPPTTIINNGG below)
- and used as the primary prompt string. The default value is
+ PPSS11 The value of this parameter is expanded (see PPRROOMMPPTTIINNGG below)
+ and used as the primary prompt string. The default value is
``\\ss--\\vv\\$$ ''.
- PPSS22 The value of this parameter is expanded as with PPSS11 and used as
+ PPSS22 The value of this parameter is expanded as with PPSS11 and used as
the secondary prompt string. The default is ``>> ''.
PPSS33 The value of this parameter is used as the prompt for the sseelleecctt
command (see SSHHEELLLL GGRRAAMMMMAARR above).
- PPSS44 The value of this parameter is expanded as with PPSS11 and the
- value is printed before each command bbaasshh displays during an
- execution trace. The first character of PPSS44 is replicated mul-
- tiple times, as necessary, to indicate multiple levels of indi-
+ PPSS44 The value of this parameter is expanded as with PPSS11 and the
+ value is printed before each command bbaasshh displays during an
+ execution trace. The first character of PPSS44 is replicated mul-
+ tiple times, as necessary, to indicate multiple levels of indi-
rection. The default is ``++ ''.
SSHHEELLLL The full pathname to the shell is kept in this environment vari-
- able. If it is not set when the shell starts, bbaasshh assigns to
+ able. If it is not set when the shell starts, bbaasshh assigns to
it the full pathname of the current user's login shell.
TTIIMMEEFFOORRMMAATT
- The value of this parameter is used as a format string specify-
- ing how the timing information for pipelines prefixed with the
- ttiimmee reserved word should be displayed. The %% character intro-
- duces an escape sequence that is expanded to a time value or
- other information. The escape sequences and their meanings are
+ The value of this parameter is used as a format string specify-
+ ing how the timing information for pipelines prefixed with the
+ ttiimmee reserved word should be displayed. The %% character intro-
+ duces 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.
%%%% A literal %%.
%%[[_p]][[ll]]RR The elapsed time in seconds.
@@ -1177,189 +1190,189 @@ PPAARRAAMMEETTEERRSS
%%[[_p]][[ll]]SS The number of CPU seconds spent in system mode.
%%PP The CPU percentage, computed as (%U + %S) / %R.
- The optional _p is a digit specifying the _p_r_e_c_i_s_i_o_n, the number
+ The optional _p is a digit specifying the _p_r_e_c_i_s_i_o_n, 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 _p greater
- than 3 are changed to 3. If _p is not specified, the value 3 is
+ after the decimal point may be specified; values of _p greater
+ than 3 are changed to 3. If _p is not specified, the value 3 is
used.
- The optional ll specifies a longer format, including minutes, of
- the form _M_Mm_S_S._F_Fs. The value of _p determines whether or not
+ The optional ll specifies a longer format, including minutes, of
+ the form _M_Mm_S_S._F_Fs. The value of _p determines whether or not
the fraction is included.
- If this variable is not set, bbaasshh acts as if it had the value
- $$''\\nnrreeaall\\tt%%33llRR\\nnuusseerr\\tt%%33llUU\\nnssyyss%%33llSS''. If the value is null, no
- timing information is displayed. A trailing newline is added
+ If this variable is not set, bbaasshh acts as if it had the value
+ $$''\\nnrreeaall\\tt%%33llRR\\nnuusseerr\\tt%%33llUU\\nnssyyss%%33llSS''. If the value is null, no
+ timing information is displayed. A trailing newline is added
when the format string is displayed.
- TTMMOOUUTT If set to a value greater than zero, TTMMOOUUTT is treated as the
+ TTMMOOUUTT If set to a value greater than zero, TTMMOOUUTT is treated as the
default timeout for the rreeaadd builtin. The sseelleecctt command termi-
nates if input does not arrive after TTMMOOUUTT seconds when input is
- coming from a terminal. In an interactive shell, the value is
- interpreted as the number of seconds to wait for input after
- issuing the primary prompt. BBaasshh terminates after waiting for
+ coming from a terminal. In an interactive shell, the value is
+ interpreted as the number of seconds to wait for input after
+ issuing the primary prompt. BBaasshh terminates after waiting for
that number of seconds if input does not arrive.
- TTMMPPDDIIRR If set, bbaasshh uses its value as the name of a directory in which
+ TTMMPPDDIIRR If set, bbaasshh uses its value as the name of a directory in which
bbaasshh creates temporary files for the shell's use.
aauuttoo__rreessuummee
This variable controls how the shell interacts with the user and
- job control. If this variable is set, single word simple com-
+ job control. If this variable is set, single word simple com-
mands without redirections are treated as candidates for resump-
tion of an existing stopped job. There is no ambiguity allowed;
- if there is more than one job beginning with the string typed,
- the job most recently accessed is selected. The _n_a_m_e of a
- stopped job, in this context, is the command line used to start
- it. If set to the value _e_x_a_c_t, the string supplied must match
- the name of a stopped job exactly; if set to _s_u_b_s_t_r_i_n_g, the
- string supplied needs to match a substring of the name of a
- stopped job. The _s_u_b_s_t_r_i_n_g value provides functionality analo-
- gous to the %%?? job identifier (see JJOOBB CCOONNTTRROOLL below). If set
- to any other value, the supplied string must be a prefix of a
+ if there is more than one job beginning with the string typed,
+ the job most recently accessed is selected. The _n_a_m_e of a
+ stopped job, in this context, is the command line used to start
+ it. If set to the value _e_x_a_c_t, the string supplied must match
+ the name of a stopped job exactly; if set to _s_u_b_s_t_r_i_n_g, the
+ string supplied needs to match a substring of the name of a
+ stopped job. The _s_u_b_s_t_r_i_n_g value provides functionality analo-
+ gous to the %%?? job identifier (see JJOOBB CCOONNTTRROOLL below). 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
%%_s_t_r_i_n_g job identifier.
hhiissttcchhaarrss
- The two or three characters which control history expansion and
+ The two or three characters which control history expansion and
tokenization (see HHIISSTTOORRYY EEXXPPAANNSSIIOONN below). The first character
- is the _h_i_s_t_o_r_y _e_x_p_a_n_s_i_o_n character, the character which signals
- the start of a history expansion, normally `!!'. The second
- character is the _q_u_i_c_k _s_u_b_s_t_i_t_u_t_i_o_n character, which is used as
- shorthand for re-running the previous command entered, substi-
- tuting one string for another in the command. The default is
- `^^'. The optional third character is the character which indi-
- cates that the remainder of the line is a comment when found as
- the first character of a word, normally `##'. The history com-
+ is the _h_i_s_t_o_r_y _e_x_p_a_n_s_i_o_n character, the character which signals
+ the start of a history expansion, normally `!!'. The second
+ character is the _q_u_i_c_k _s_u_b_s_t_i_t_u_t_i_o_n character, which is used as
+ shorthand for re-running the previous command entered, substi-
+ tuting one string for another in the command. The default is
+ `^^'. The optional third character is the character which indi-
+ cates that the remainder of the line is a comment when found as
+ the first character of a word, normally `##'. The history com-
ment character causes history substitution to be skipped for the
- remaining words on the line. It does not necessarily cause the
+ remaining words on the line. It does not necessarily cause the
shell parser to treat the rest of the line as a comment.
AArrrraayyss
- BBaasshh provides one-dimensional indexed and associative array variables.
- Any variable may be used as an indexed array; the ddeeccllaarree 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 con-
- tiguously. Indexed arrays are referenced using integers (including
- arithmetic expressions) and are zero-based; associative arrays are
+ BBaasshh provides one-dimensional indexed and associative array variables.
+ Any variable may be used as an indexed array; the ddeeccllaarree 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 con-
+ tiguously. Indexed arrays are referenced using integers (including
+ arithmetic expressions) and are zero-based; associative arrays are
referenced using arbitrary strings.
- An indexed array is created automatically if any variable is assigned
+ An indexed array is created automatically if any variable is assigned
to using the syntax _n_a_m_e[_s_u_b_s_c_r_i_p_t]=_v_a_l_u_e. The _s_u_b_s_c_r_i_p_t is treated as
an arithmetic expression that must evaluate to a number. To explicitly
- declare an indexed array, use ddeeccllaarree --aa _n_a_m_e (see SSHHEELLLL BBUUIILLTTIINN CCOOMM--
- MMAANNDDSS below). ddeeccllaarree --aa _n_a_m_e[[_s_u_b_s_c_r_i_p_t]] is also accepted; the _s_u_b_-
+ declare an indexed array, use ddeeccllaarree --aa _n_a_m_e (see SSHHEELLLL BBUUIILLTTIINN CCOOMM--
+ MMAANNDDSS below). ddeeccllaarree --aa _n_a_m_e[[_s_u_b_s_c_r_i_p_t]] is also accepted; the _s_u_b_-
_s_c_r_i_p_t is ignored.
Associative arrays are created using ddeeccllaarree --AA _n_a_m_e.
Attributes may be specified for an array variable using the ddeeccllaarree and
- rreeaaddoonnllyy builtins. Each attribute applies to all members of an array.
+ rreeaaddoonnllyy builtins. Each attribute applies to all members of an array.
- Arrays are assigned to using compound assignments of the form
- _n_a_m_e=((value_1 ... value_n)), where each _v_a_l_u_e is of the form [_s_u_b_-
- _s_c_r_i_p_t]=_s_t_r_i_n_g. Indexed array assignments do not require anything but
+ Arrays are assigned to using compound assignments of the form
+ _n_a_m_e=((value_1 ... value_n)), where each _v_a_l_u_e is of the form [_s_u_b_-
+ _s_c_r_i_p_t]=_s_t_r_i_n_g. Indexed array assignments do not require anything but
_s_t_r_i_n_g. When assigning to indexed arrays, if the optional brackets and
- subscript are supplied, that index is assigned to; otherwise the index
- of the element assigned is the last index assigned to by the statement
+ subscript are 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.
When assigning to an associative array, the subscript is required.
- This syntax is also accepted by the ddeeccllaarree builtin. Individual array
- elements may be assigned to using the _n_a_m_e[_s_u_b_s_c_r_i_p_t]=_v_a_l_u_e syntax
+ This syntax is also accepted by the ddeeccllaarree builtin. Individual array
+ elements may be assigned to using the _n_a_m_e[_s_u_b_s_c_r_i_p_t]=_v_a_l_u_e syntax
introduced above.
- Any element of an array may be referenced using ${_n_a_m_e[_s_u_b_s_c_r_i_p_t]}.
+ Any element of an array may be referenced using ${_n_a_m_e[_s_u_b_s_c_r_i_p_t]}.
The braces are required to avoid conflicts with pathname expansion. If
- _s_u_b_s_c_r_i_p_t is @@ or **, the word expands to all members of _n_a_m_e. These
- subscripts differ only when the word appears within double quotes. If
+ _s_u_b_s_c_r_i_p_t is @@ or **, the word expands to all members of _n_a_m_e. These
+ subscripts differ only when the word appears within double quotes. If
the word is double-quoted, ${_n_a_m_e[*]} expands to a single word with the
- value of each array member separated by the first character of the IIFFSS
+ value of each array member separated by the first character of the IIFFSS
special variable, and ${_n_a_m_e[@]} expands each element of _n_a_m_e to a sep-
- arate word. When there are no array members, ${_n_a_m_e[@]} 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 ** and @@ (see SSppeecciiaall PPaarraammeetteerrss
- above). ${#_n_a_m_e[_s_u_b_s_c_r_i_p_t]} expands to the length of ${_n_a_m_e[_s_u_b_-
- _s_c_r_i_p_t]}. If _s_u_b_s_c_r_i_p_t is ** or @@, the expansion is the number of ele-
- ments in the array. Referencing an array variable without a subscript
- is equivalent to referencing the array with a subscript of 0. If the
+ arate word. When there are no array members, ${_n_a_m_e[@]} 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 ** and @@ (see SSppeecciiaall PPaarraammeetteerrss
+ above). ${#_n_a_m_e[_s_u_b_s_c_r_i_p_t]} expands to the length of ${_n_a_m_e[_s_u_b_-
+ _s_c_r_i_p_t]}. If _s_u_b_s_c_r_i_p_t is ** or @@, the expansion is the number of ele-
+ ments in the array. Referencing an array variable without a subscript
+ is equivalent to referencing the array with a subscript of 0. If the
_s_u_b_s_c_r_i_p_t used to reference an element of an indexed array evaluates to
- a number less than zero, it is used as an offset from one greater than
- the array's maximum index (so a subcript of -1 refers to the last ele-
+ a number less than zero, it is used as an offset from one greater than
+ the array's maximum index (so a subcript of -1 refers to the last ele-
ment of the array).
- An array variable is considered set if a subscript has been assigned a
+ An array variable is considered set if a subscript has been assigned a
value. The null string is a valid value.
- The uunnsseett builtin is used to destroy arrays. uunnsseett _n_a_m_e[_s_u_b_s_c_r_i_p_t]
- destroys the array element at index _s_u_b_s_c_r_i_p_t. Care must be taken to
- avoid unwanted side effects caused by pathname expansion. uunnsseett _n_a_m_e,
- where _n_a_m_e is an array, or uunnsseett _n_a_m_e[_s_u_b_s_c_r_i_p_t], where _s_u_b_s_c_r_i_p_t is **
+ The uunnsseett builtin is used to destroy arrays. uunnsseett _n_a_m_e[_s_u_b_s_c_r_i_p_t]
+ destroys the array element at index _s_u_b_s_c_r_i_p_t. Care must be taken to
+ avoid unwanted side effects caused by pathname expansion. uunnsseett _n_a_m_e,
+ where _n_a_m_e is an array, or uunnsseett _n_a_m_e[_s_u_b_s_c_r_i_p_t], where _s_u_b_s_c_r_i_p_t is **
or @@, removes the entire array.
- The ddeeccllaarree, llooccaall, and rreeaaddoonnllyy builtins each accept a --aa option to
- specify an indexed array and a --AA option to specify an associative
- array. If both options are supplied, --AA takes precedence. The rreeaadd
- builtin accepts a --aa option to assign a list of words read from the
+ The ddeeccllaarree, llooccaall, and rreeaaddoonnllyy builtins each accept a --aa option to
+ specify an indexed array and a --AA option to specify an associative
+ array. If both options are supplied, --AA takes precedence. The rreeaadd
+ builtin accepts a --aa option to assign a list of words read from the
standard input to an array. The sseett and ddeeccllaarree builtins display array
values in a way that allows them to be reused as assignments.
EEXXPPAANNSSIIOONN
Expansion is performed on the command line after it has been split into
- words. There are seven kinds of expansion performed: _b_r_a_c_e _e_x_p_a_n_s_i_o_n,
- _t_i_l_d_e _e_x_p_a_n_s_i_o_n, _p_a_r_a_m_e_t_e_r _a_n_d _v_a_r_i_a_b_l_e _e_x_p_a_n_s_i_o_n, _c_o_m_m_a_n_d _s_u_b_s_t_i_t_u_-
+ words. There are seven kinds of expansion performed: _b_r_a_c_e _e_x_p_a_n_s_i_o_n,
+ _t_i_l_d_e _e_x_p_a_n_s_i_o_n, _p_a_r_a_m_e_t_e_r _a_n_d _v_a_r_i_a_b_l_e _e_x_p_a_n_s_i_o_n, _c_o_m_m_a_n_d _s_u_b_s_t_i_t_u_-
_t_i_o_n, _a_r_i_t_h_m_e_t_i_c _e_x_p_a_n_s_i_o_n, _w_o_r_d _s_p_l_i_t_t_i_n_g, and _p_a_t_h_n_a_m_e _e_x_p_a_n_s_i_o_n.
- The order of expansions is: brace expansion, tilde expansion, parame-
- ter, variable and arithmetic expansion and command substitution (done
+ The order of expansions is: brace expansion, tilde expansion, parame-
+ ter, variable and arithmetic expansion and command substitution (done
in a left-to-right fashion), word splitting, and pathname expansion.
On systems that can support it, there is an additional expansion avail-
able: _p_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n.
Only brace expansion, word splitting, and pathname 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
+ 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 "$$@@" and "$${{_n_a_m_e[[@@]]}}" as explained above (see PPAARRAAMMEETTEERRSS).
BBrraaccee EExxppaannssiioonn
_B_r_a_c_e _e_x_p_a_n_s_i_o_n is a mechanism by which arbitrary strings may be gener-
- ated. This mechanism is similar to _p_a_t_h_n_a_m_e _e_x_p_a_n_s_i_o_n, but the file-
+ ated. This mechanism is similar to _p_a_t_h_n_a_m_e _e_x_p_a_n_s_i_o_n, but the file-
names generated need not exist. Patterns to be brace expanded take the
form of an optional _p_r_e_a_m_b_l_e, followed by either a series of comma-sep-
- arated strings or a sequence expression between a pair of braces, fol-
- lowed by an optional _p_o_s_t_s_c_r_i_p_t. The preamble is prefixed to each
+ arated strings or a sequence expression between a pair of braces, fol-
+ lowed by an optional _p_o_s_t_s_c_r_i_p_t. 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.
- Brace expansions may be nested. The results of each expanded string
- are not sorted; left to right order is preserved. For example,
+ Brace expansions may be nested. The results of each expanded string
+ are not sorted; left to right order is preserved. For example,
a{{d,c,b}}e expands into `ade ace abe'.
- A sequence expression takes the form {{_x...._y[[...._i_n_c_r]]}}, where _x and _y are
- either integers or single characters, and _i_n_c_r, an optional increment,
- is an integer. When integers are supplied, the expression expands to
- each number between _x and _y, inclusive. Supplied integers may be pre-
- fixed with _0 to force each term to have the same width. When either _x
- or _y begins with a zero, the shell attempts to force all generated
- terms to contain the same number of digits, zero-padding where neces-
- sary. When characters are supplied, the expression expands to each
+ A sequence expression takes the form {{_x...._y[[...._i_n_c_r]]}}, where _x and _y are
+ either integers or single characters, and _i_n_c_r, an optional increment,
+ is an integer. When integers are supplied, the expression expands to
+ each number between _x and _y, inclusive. Supplied integers may be pre-
+ fixed with _0 to force each term to have the same width. When either _x
+ or _y begins with a zero, the shell attempts to force all generated
+ terms to contain the same number of digits, zero-padding where neces-
+ sary. When characters are supplied, the expression expands to each
character lexicographically between _x and _y, inclusive. Note that both
- _x and _y must be of the same type. When the increment is supplied, it
- is used as the difference between each term. The default increment is
+ _x and _y must be of the same type. When the increment is supplied, it
+ is used as the difference between each term. The default increment is
1 or -1 as appropriate.
Brace expansion is performed before any other expansions, and any char-
- acters special to other expansions are preserved in the result. It is
- strictly textual. BBaasshh does not apply any syntactic interpretation to
+ acters special to other expansions are preserved in the result. It is
+ strictly textual. BBaasshh does not apply any syntactic interpretation to
the context of the expansion or the text between the braces.
- 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.
+ 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.
A {{ or ,, may be quoted with a backslash to prevent its being considered
- part of a brace expression. To avoid conflicts with parameter expan-
+ part of a brace expression. To avoid conflicts with parameter expan-
sion, the string $${{ is not considered eligible for brace expansion.
This construct is typically used as shorthand when the common prefix of
@@ -1369,36 +1382,36 @@ EEXXPPAANNSSIIOONN
or
chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}}
- Brace expansion introduces a slight incompatibility with historical
- versions of sshh. sshh does not treat opening or closing braces specially
- when they appear as part of a word, and preserves them in the output.
- BBaasshh removes braces from words as a consequence of brace expansion.
- For example, a word entered to sshh as _f_i_l_e_{_1_,_2_} appears identically in
- the output. The same word is output as _f_i_l_e_1 _f_i_l_e_2 after expansion by
- bbaasshh. If strict compatibility with sshh is desired, start bbaasshh with the
+ Brace expansion introduces a slight incompatibility with historical
+ versions of sshh. sshh does not treat opening or closing braces specially
+ when they appear as part of a word, and preserves them in the output.
+ BBaasshh removes braces from words as a consequence of brace expansion.
+ For example, a word entered to sshh as _f_i_l_e_{_1_,_2_} appears identically in
+ the output. The same word is output as _f_i_l_e_1 _f_i_l_e_2 after expansion by
+ bbaasshh. If strict compatibility with sshh is desired, start bbaasshh with the
++BB option or disable brace expansion with the ++BB option to the sseett com-
mand (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
TTiillddee EExxppaannssiioonn
- If a word begins with an unquoted tilde character (`~~'), all of the
- characters preceding the first unquoted slash (or all characters, if
- there is no unquoted slash) are considered a _t_i_l_d_e_-_p_r_e_f_i_x. 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 _l_o_g_i_n _n_a_m_e.
- If this login name is the null string, the tilde is replaced with the
- value of the shell parameter HHOOMMEE. If HHOOMMEE is unset, the home direc-
- tory of the user executing the shell is substituted instead. Other-
- wise, the tilde-prefix is replaced with the home directory associated
+ If a word begins with an unquoted tilde character (`~~'), all of the
+ characters preceding the first unquoted slash (or all characters, if
+ there is no unquoted slash) are considered a _t_i_l_d_e_-_p_r_e_f_i_x. 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 _l_o_g_i_n _n_a_m_e.
+ If this login name is the null string, the tilde is replaced with the
+ value of the shell parameter HHOOMMEE. If HHOOMMEE is unset, the home direc-
+ tory of the user executing the shell is substituted instead. Other-
+ wise, the tilde-prefix is replaced with the home directory associated
with the specified login name.
- If the tilde-prefix is a `~+', the value of the shell variable PPWWDD
+ If the tilde-prefix is a `~+', the value of the shell variable PPWWDD
replaces the tilde-prefix. If the tilde-prefix is a `~-', the value of
- the shell variable OOLLDDPPWWDD, if it is set, is substituted. If the char-
- acters following the tilde in the tilde-prefix consist of a number _N,
- optionally prefixed by a `+' or a `-', the tilde-prefix is replaced
+ the shell variable OOLLDDPPWWDD, if it is set, is substituted. If the char-
+ acters following the tilde in the tilde-prefix consist of a number _N,
+ optionally prefixed by a `+' or a `-', the tilde-prefix is replaced
with the corresponding element from the directory stack, as it would be
displayed by the ddiirrss builtin invoked with the tilde-prefix as an argu-
- ment. If the characters following the tilde in the tilde-prefix con-
+ ment. If the characters following the tilde in the tilde-prefix con-
sist of a number without a leading `+' or `-', `+' is assumed.
If the login name is invalid, or the tilde expansion fails, the word is
@@ -1406,177 +1419,180 @@ EEXXPPAANNSSIIOONN
Each variable assignment is checked for unquoted tilde-prefixes immedi-
ately following a :: or the first ==. In these cases, tilde expansion is
- also performed. Consequently, one may use filenames with tildes in
- assignments to PPAATTHH, MMAAIILLPPAATTHH, and CCDDPPAATTHH, and the shell assigns the
+ also performed. Consequently, one may use filenames with tildes in
+ assignments to PPAATTHH, MMAAIILLPPAATTHH, and CCDDPPAATTHH, and the shell assigns the
expanded value.
PPaarraammeetteerr EExxppaannssiioonn
The `$$' 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
+ 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.
- When braces are used, the matching ending brace is the first `}}' not
- escaped by a backslash or within a quoted string, and not within an
+ When braces are used, the matching ending brace is the first `}}' not
+ escaped by a backslash or within a quoted string, and not within an
embedded arithmetic expansion, command substitution, or parameter
expansion.
${_p_a_r_a_m_e_t_e_r}
- The value of _p_a_r_a_m_e_t_e_r is substituted. The braces are required
- when _p_a_r_a_m_e_t_e_r is a positional parameter with more than one
+ The value of _p_a_r_a_m_e_t_e_r is substituted. The braces are required
+ when _p_a_r_a_m_e_t_e_r is a positional parameter with more than one
digit, or when _p_a_r_a_m_e_t_e_r is followed by a character which is not
to be interpreted as part of its name.
- If the first character of _p_a_r_a_m_e_t_e_r is an exclamation point (!!), a
- level of variable indirection is introduced. BBaasshh uses the value of
+ If the first character of _p_a_r_a_m_e_t_e_r is an exclamation point (!!), a
+ level of variable indirection is introduced. BBaasshh uses the value of
the variable formed from the rest of _p_a_r_a_m_e_t_e_r as the name of the vari-
able; this variable is then expanded and that value is used in the rest
- of the substitution, rather than the value of _p_a_r_a_m_e_t_e_r itself. This
- is known as _i_n_d_i_r_e_c_t _e_x_p_a_n_s_i_o_n. The exceptions to this are the expan-
- sions of ${!!_p_r_e_f_i_x**} and ${!!_n_a_m_e[_@]} described below. The exclamation
- point must immediately follow the left brace in order to introduce
+ of the substitution, rather than the value of _p_a_r_a_m_e_t_e_r itself. This
+ is known as _i_n_d_i_r_e_c_t _e_x_p_a_n_s_i_o_n. The exceptions to this are the expan-
+ sions of ${!!_p_r_e_f_i_x**} and ${!!_n_a_m_e[_@]} described below. The exclamation
+ point must immediately follow the left brace in order to introduce
indirection.
In each of the cases below, _w_o_r_d is subject to tilde expansion, parame-
ter expansion, command substitution, and arithmetic expansion.
- When not performing substring expansion, using the forms documented
- below, bbaasshh tests for a parameter that is unset or null. Omitting the
+ When not performing substring expansion, using the forms documented
+ below, bbaasshh tests for a parameter that is unset or null. Omitting the
colon results in a test only for a parameter that is unset.
${_p_a_r_a_m_e_t_e_r::--_w_o_r_d}
- UUssee DDeeffaauulltt VVaalluueess. If _p_a_r_a_m_e_t_e_r is unset or null, the expan-
- sion of _w_o_r_d is substituted. Otherwise, the value of _p_a_r_a_m_e_t_e_r
+ UUssee DDeeffaauulltt VVaalluueess. If _p_a_r_a_m_e_t_e_r is unset or null, the expan-
+ sion of _w_o_r_d is substituted. Otherwise, the value of _p_a_r_a_m_e_t_e_r
is substituted.
${_p_a_r_a_m_e_t_e_r::==_w_o_r_d}
- AAssssiiggnn DDeeffaauulltt VVaalluueess. If _p_a_r_a_m_e_t_e_r is unset or null, the
+ AAssssiiggnn DDeeffaauulltt VVaalluueess. If _p_a_r_a_m_e_t_e_r is unset or null, the
expansion of _w_o_r_d is assigned to _p_a_r_a_m_e_t_e_r. The value of _p_a_r_a_m_-
- _e_t_e_r is then substituted. Positional parameters and special
+ _e_t_e_r is then substituted. Positional parameters and special
parameters may not be assigned to in this way.
${_p_a_r_a_m_e_t_e_r::??_w_o_r_d}
- DDiissppllaayy EErrrroorr iiff NNuullll oorr UUnnsseett. If _p_a_r_a_m_e_t_e_r is null or unset,
- the expansion of _w_o_r_d (or a message to that effect if _w_o_r_d is
- not present) is written to the standard error and the shell, if
+ DDiissppllaayy EErrrroorr iiff NNuullll oorr UUnnsseett. If _p_a_r_a_m_e_t_e_r is null or unset,
+ the expansion of _w_o_r_d (or a message to that effect if _w_o_r_d is
+ not present) is written to the standard error and the shell, if
it is not interactive, exits. Otherwise, the value of _p_a_r_a_m_e_t_e_r
is substituted.
${_p_a_r_a_m_e_t_e_r::++_w_o_r_d}
- UUssee AAlltteerrnnaattee VVaalluuee. If _p_a_r_a_m_e_t_e_r is null or unset, nothing is
+ UUssee AAlltteerrnnaattee VVaalluuee. If _p_a_r_a_m_e_t_e_r is null or unset, nothing is
substituted, otherwise the expansion of _w_o_r_d is substituted.
${_p_a_r_a_m_e_t_e_r::_o_f_f_s_e_t}
${_p_a_r_a_m_e_t_e_r::_o_f_f_s_e_t::_l_e_n_g_t_h}
- SSuubbssttrriinngg EExxppaannssiioonn. Expands to up to _l_e_n_g_t_h characters of
- _p_a_r_a_m_e_t_e_r starting at the character specified by _o_f_f_s_e_t. If
- _l_e_n_g_t_h is omitted, expands to the substring of _p_a_r_a_m_e_t_e_r start-
+ SSuubbssttrriinngg EExxppaannssiioonn. Expands to up to _l_e_n_g_t_h characters of
+ _p_a_r_a_m_e_t_e_r starting at the character specified by _o_f_f_s_e_t. If
+ _l_e_n_g_t_h is omitted, expands to the substring of _p_a_r_a_m_e_t_e_r start-
ing at the character specified by _o_f_f_s_e_t. _l_e_n_g_t_h and _o_f_f_s_e_t are
- arithmetic expressions (see AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN below). If
- _o_f_f_s_e_t evaluates to a number less than zero, the value is used
- as an offset from the end of the value of _p_a_r_a_m_e_t_e_r. If _l_e_n_g_t_h
+ arithmetic expressions (see AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN below). If
+ _o_f_f_s_e_t evaluates to a number less than zero, the value is used
+ as an offset from the end of the value of _p_a_r_a_m_e_t_e_r. If _l_e_n_g_t_h
evaluates to a number less than zero, and _p_a_r_a_m_e_t_e_r is not @@ and
- not an indexed or associative array, it is interpreted as an
+ not an indexed or associative array, it is interpreted as an
offset from the end of the value of _p_a_r_a_m_e_t_e_r rather than a num-
- ber of characters, and the expansion is the characters between
- the two offsets. If _p_a_r_a_m_e_t_e_r is @@, the result is _l_e_n_g_t_h posi-
- tional parameters beginning at _o_f_f_s_e_t. If _p_a_r_a_m_e_t_e_r is an
- indexed array name subscripted by @ or *, the result is the
+ ber of characters, and the expansion is the characters between
+ the two offsets. If _p_a_r_a_m_e_t_e_r is @@, the result is _l_e_n_g_t_h posi-
+ tional parameters beginning at _o_f_f_s_e_t. If _p_a_r_a_m_e_t_e_r is an
+ indexed array name subscripted by @ or *, the result is the
_l_e_n_g_t_h members of the array beginning with ${_p_a_r_a_m_e_t_e_r[_o_f_f_s_e_t]}.
A negative _o_f_f_s_e_t is taken relative to one greater than the max-
- imum index of the specified array. Substring expansion applied
+ imum index of the specified array. Substring expansion applied
to an associative array produces undefined results. Note that a
negative offset must be separated from the colon by at least one
- space to avoid being confused with the :- expansion. Substring
- indexing is zero-based unless the positional parameters are
- used, in which case the indexing starts at 1 by default. If
- _o_f_f_s_e_t is 0, and the positional parameters are used, $$00 is pre-
+ space to avoid being confused with the :- expansion. Substring
+ indexing is zero-based unless the positional parameters are
+ used, in which case the indexing starts at 1 by default. If
+ _o_f_f_s_e_t is 0, and the positional parameters are used, $$00 is pre-
fixed to the list.
${!!_p_r_e_f_i_x**}
${!!_p_r_e_f_i_x@@}
- NNaammeess mmaattcchhiinngg pprreeffiixx. Expands to the names of variables whose
+ NNaammeess mmaattcchhiinngg pprreeffiixx. Expands to the names of variables whose
names begin with _p_r_e_f_i_x, separated by the first character of the
- IIFFSS special variable. When _@ is used and the expansion appears
- within double quotes, each variable name expands to a separate
+ IIFFSS special variable. When _@ is used and the expansion appears
+ within double quotes, each variable name expands to a separate
word.
${!!_n_a_m_e[_@]}
${!!_n_a_m_e[_*]}
- LLiisstt ooff aarrrraayy kkeeyyss. If _n_a_m_e is an array variable, expands to
- the list of array indices (keys) assigned in _n_a_m_e. If _n_a_m_e is
- not an array, expands to 0 if _n_a_m_e is set and null otherwise.
- When _@ is used and the expansion appears within double quotes,
+ LLiisstt ooff aarrrraayy kkeeyyss. If _n_a_m_e is an array variable, expands to
+ the list of array indices (keys) assigned in _n_a_m_e. If _n_a_m_e is
+ not an array, expands to 0 if _n_a_m_e is set and null otherwise.
+ When _@ is used and the expansion appears within double quotes,
each key expands to a separate word.
${##_p_a_r_a_m_e_t_e_r}
- PPaarraammeetteerr lleennggtthh. The length in characters of the value of
- _p_a_r_a_m_e_t_e_r is substituted. If _p_a_r_a_m_e_t_e_r is ** or @@, the value
- substituted is the number of positional parameters. If _p_a_r_a_m_e_-
- _t_e_r is an array name subscripted by ** or @@, the value substi-
+ PPaarraammeetteerr lleennggtthh. The length in characters of the value of
+ _p_a_r_a_m_e_t_e_r is substituted. If _p_a_r_a_m_e_t_e_r is ** or @@, the value
+ substituted is the number of positional parameters. If _p_a_r_a_m_e_-
+ _t_e_r is an array name subscripted by ** or @@, the value substi-
tuted is the number of elements in the array.
${_p_a_r_a_m_e_t_e_r##_w_o_r_d}
${_p_a_r_a_m_e_t_e_r####_w_o_r_d}
RReemmoovvee mmaattcchhiinngg pprreeffiixx ppaatttteerrnn. The _w_o_r_d is expanded to produce
a pattern just as in pathname expansion. If the pattern matches
- the beginning of the value of _p_a_r_a_m_e_t_e_r, then the result of the
- expansion is the expanded value of _p_a_r_a_m_e_t_e_r with the shortest
- matching pattern (the ``##'' case) or the longest matching pat-
- tern (the ``####'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@ or **, the
- pattern removal operation is applied to each positional parame-
+ the beginning of the value of _p_a_r_a_m_e_t_e_r, then the result of the
+ expansion is the expanded value of _p_a_r_a_m_e_t_e_r with the shortest
+ matching pattern (the ``##'' case) or the longest matching pat-
+ tern (the ``####'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@ or **, the
+ pattern removal operation is applied to each positional parame-
ter in turn, and the expansion is the resultant list. If _p_a_r_a_m_-
- _e_t_e_r is an array variable subscripted with @@ or **, the pattern
- removal operation is applied to each member of the array in
+ _e_t_e_r is an array variable subscripted with @@ or **, the pattern
+ removal operation is applied to each member of the array in
turn, and the expansion is the resultant list.
${_p_a_r_a_m_e_t_e_r%%_w_o_r_d}
${_p_a_r_a_m_e_t_e_r%%%%_w_o_r_d}
RReemmoovvee mmaattcchhiinngg ssuuffffiixx ppaatttteerrnn. The _w_o_r_d is expanded to produce
a pattern just as in pathname expansion. If the pattern matches
- a trailing portion of the expanded value of _p_a_r_a_m_e_t_e_r, then the
- result of the expansion is the expanded value of _p_a_r_a_m_e_t_e_r with
- the shortest matching pattern (the ``%%'' case) or the longest
- matching pattern (the ``%%%%'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@
- or **, the pattern removal operation is applied to each posi-
- tional parameter in turn, and the expansion is the resultant
- list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted with @@ or
- **, the pattern removal operation is applied to each member of
+ a trailing portion of the expanded value of _p_a_r_a_m_e_t_e_r, then the
+ result of the expansion is the expanded value of _p_a_r_a_m_e_t_e_r with
+ the shortest matching pattern (the ``%%'' case) or the longest
+ matching pattern (the ``%%%%'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@
+ or **, the pattern removal operation is applied to each posi-
+ tional parameter in turn, and the expansion is the resultant
+ list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted with @@ or
+ **, the pattern removal operation is applied to each member of
the array in turn, and the expansion is the resultant list.
${_p_a_r_a_m_e_t_e_r//_p_a_t_t_e_r_n//_s_t_r_i_n_g}
PPaatttteerrnn ssuubbssttiittuuttiioonn. The _p_a_t_t_e_r_n is expanded to produce a pat-
- tern just as in pathname expansion. _P_a_r_a_m_e_t_e_r is expanded and
- the longest match of _p_a_t_t_e_r_n against its value is replaced with
- _s_t_r_i_n_g. If _p_a_t_t_e_r_n begins with //, all matches of _p_a_t_t_e_r_n are
- replaced with _s_t_r_i_n_g. Normally only the first match is
+ tern just as in pathname expansion. _P_a_r_a_m_e_t_e_r is expanded and
+ the longest match of _p_a_t_t_e_r_n against its value is replaced with
+ _s_t_r_i_n_g. If _p_a_t_t_e_r_n begins with //, all matches of _p_a_t_t_e_r_n are
+ replaced with _s_t_r_i_n_g. Normally only the first match is
replaced. If _p_a_t_t_e_r_n begins with ##, it must match at the begin-
ning of the expanded value of _p_a_r_a_m_e_t_e_r. If _p_a_t_t_e_r_n begins with
- %%, it must match at the end of the expanded value of _p_a_r_a_m_e_t_e_r.
+ %%, it must match at the end of the expanded value of _p_a_r_a_m_e_t_e_r.
If _s_t_r_i_n_g is null, matches of _p_a_t_t_e_r_n are deleted and the // fol-
lowing _p_a_t_t_e_r_n may be omitted. If _p_a_r_a_m_e_t_e_r is @@ or **, the sub-
- stitution operation is applied to each positional parameter in
- turn, and the expansion is the resultant list. If _p_a_r_a_m_e_t_e_r is
- an array variable subscripted with @@ or **, the substitution
- operation is applied to each member of the array in turn, and
+ stitution operation is applied to each positional parameter in
+ turn, and the expansion is the resultant list. If _p_a_r_a_m_e_t_e_r is
+ an array variable subscripted with @@ or **, the substitution
+ operation is applied to each member of the array in turn, and
the expansion is the resultant list.
${_p_a_r_a_m_e_t_e_r^^_p_a_t_t_e_r_n}
${_p_a_r_a_m_e_t_e_r^^^^_p_a_t_t_e_r_n}
${_p_a_r_a_m_e_t_e_r,,_p_a_t_t_e_r_n}
${_p_a_r_a_m_e_t_e_r,,,,_p_a_t_t_e_r_n}
- CCaassee mmooddiiffiiccaattiioonn. This expansion modifies the case of alpha-
- betic characters in _p_a_r_a_m_e_t_e_r. The _p_a_t_t_e_r_n is expanded to pro-
- duce a pattern just as in pathname expansion. The ^^ operator
- converts lowercase letters matching _p_a_t_t_e_r_n to uppercase; the ,,
- operator converts matching uppercase letters to lowercase. The
- ^^^^ and ,,,, expansions convert each matched character in the
- expanded value; the ^^ and ,, expansions match and convert only
- the first character in the expanded value. If _p_a_t_t_e_r_n is omit-
- ted, it is treated like a ??, which matches every character. If
- _p_a_r_a_m_e_t_e_r is @@ or **, the case modification operation is applied
- to each positional parameter in turn, and the expansion is the
- resultant list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted
- with @@ or **, the case modification operation is applied to each
- member of the array in turn, and the expansion is the resultant
- list.
+ CCaassee mmooddiiffiiccaattiioonn. This expansion modifies the case of alpha-
+ betic characters in _p_a_r_a_m_e_t_e_r. The _p_a_t_t_e_r_n is expanded to pro-
+ duce a pattern just as in pathname expansion. Each character in
+ the expanded value of _p_a_r_a_m_e_t_e_r is tested against _p_a_t_t_e_r_n, and,
+ if it matches the pattern, its case is converted. The pattern
+ should not attempt to match more than one character. The ^^
+ operator converts lowercase letters matching _p_a_t_t_e_r_n to upper-
+ case; the ,, operator converts matching uppercase letters to low-
+ ercase. The ^^^^ and ,,,, expansions convert each matched character
+ in the expanded value; the ^^ and ,, expansions match and convert
+ only the first character in the expanded value. If _p_a_t_t_e_r_n is
+ omitted, it is treated like a ??, which matches every character.
+ If _p_a_r_a_m_e_t_e_r is @@ or **, the case modification operation is
+ applied to each positional parameter in turn, and the expansion
+ is the resultant list. If _p_a_r_a_m_e_t_e_r is an array variable sub-
+ scripted with @@ or **, the case modification operation is applied
+ to each member of the array in turn, and the expansion is the
+ resultant list.
CCoommmmaanndd SSuubbssttiittuuttiioonn
_C_o_m_m_a_n_d _s_u_b_s_t_i_t_u_t_i_o_n allows the output of a command to replace the com-
@@ -3332,7 +3348,9 @@ RREEAADDLLIINNEE
and store the definition.
ccaallll--llaasstt--kkbbdd--mmaaccrroo ((CC--xx ee))
Re-execute the last keyboard macro defined, by making the char-
- acters in the macro appear as if typed at the keyboard.
+ acters in the macro appear as if typed at the keyboard.
+ pprriinntt--llaasstt--kkbbdd--mmaaccrroo (()) Print the last keyboard macro defined in
+ a format suitable for the _i_n_p_u_t_r_c file.
MMiisscceellllaanneeoouuss
rree--rreeaadd--iinniitt--ffiillee ((CC--xx CC--rr))
@@ -3469,17 +3487,17 @@ RREEAADDLLIINNEE
variables are assigned values as described above under SShheellll VVaarriiaabblleess.
If a shell function is being invoked, the CCOOMMPP__WWOORRDDSS and CCOOMMPP__CCWWOORRDD
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.
+ first argument ($$11) is the name of the command whose arguments are
+ being completed, the second argument ($$22) is the word being completed,
+ and the third argument ($$33) is the word preceding the word being com-
+ pleted on the current command line. No filtering of the generated com-
+ pletions against the word being completed is performed; the function or
+ command has complete freedom in generating the matches.
Any function specified with --FF is invoked first. The function may use
any of the shell facilities, including the ccoommppggeenn builtin described
below, to generate the matches. It must put the possible completions
- in the CCOOMMPPRREEPPLLYY array variable.
+ in the CCOOMMPPRREEPPLLYY array variable, one per array element.
Next, any command specified with the --CC option is invoked in an envi-
ronment equivalent to command substitution. It should print a list of
@@ -3559,123 +3577,126 @@ HHIISSTTOORRYY
On startup, the history is initialized from the file named by the vari-
able HHIISSTTFFIILLEE (default _~_/_._b_a_s_h___h_i_s_t_o_r_y). The file named by the value
of HHIISSTTFFIILLEE is truncated, if necessary, to contain no more than the
- number of lines specified by the value of HHIISSTTFFIILLEESSIIZZEE. When the his-
- tory file is read, lines beginning with the history comment character
- followed immediately by a digit are interpreted as timestamps for the
- preceding history line. These timestamps are optionally displayed
- depending on the value of the HHIISSTTTTIIMMEEFFOORRMMAATT variable. When an inter-
- active shell exits, the last $$HHIISSTTSSIIZZEE lines are copied from the his-
- tory list to $$HHIISSTTFFIILLEE. If the hhiissttaappppeenndd shell option is enabled (see
- the description of sshhoopptt under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below), the lines
- are appended to the history file, otherwise the history file is over-
- written. If HHIISSTTFFIILLEE is unset, or if the history file is unwritable,
- the history is not saved. If the HHIISSTTTTIIMMEEFFOORRMMAATT variable is set, time
+ number of lines specified by the value of HHIISSTTFFIILLEESSIIZZEE. If HHIISSTTFFIILLEE--
+ SSIIZZEE is unset, or set to null, a non-numeric value, or a numeric value
+ less than zero, the history file is not truncated. When the history
+ file is read, lines beginning with the history comment character fol-
+ lowed immediately by a digit are interpreted as timestamps for the pre-
+ ceding history line. These timestamps are optionally displayed depend-
+ ing on the value of the HHIISSTTTTIIMMEEFFOORRMMAATT variable. When an interactive
+ shell exits, the last $$HHIISSTTSSIIZZEE lines are copied from the history list
+ to $$HHIISSTTFFIILLEE. If the hhiissttaappppeenndd shell option is enabled (see the
+ description of sshhoopptt under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below), the lines are
+ appended to the history file, otherwise the history file is overwrit-
+ ten. If HHIISSTTFFIILLEE is unset, or if the history file is unwritable, the
+ history is not saved. If the HHIISSTTTTIIMMEEFFOORRMMAATT variable is set, time
stamps are written to the history file, marked with the history comment
character, so they may be preserved across shell sessions. This uses
the history comment character to distinguish timestamps from other his-
tory lines. After saving the history, the history file is truncated to
- contain no more than HHIISSTTFFIILLEESSIIZZEE lines. If HHIISSTTFFIILLEESSIIZZEE is not set,
- no truncation is performed.
+ contain no more than HHIISSTTFFIILLEESSIIZZEE lines. If HHIISSTTFFIILLEESSIIZZEE is unset, or
+ set to null, a non-numeric value, or a numeric value less than zero,
+ the history file is not truncated.
- The builtin command ffcc (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below) may be used
+ The builtin command ffcc (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below) may be used
to list or edit and re-execute a portion of the history list. The hhiiss--
- ttoorryy 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
+ ttoorryy 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.
- The shell allows control over which commands are saved on the history
+ The shell allows control over which commands are saved on the history
list. The HHIISSTTCCOONNTTRROOLL and HHIISSTTIIGGNNOORREE variables may be set to cause the
shell to save only a subset of the commands entered. The ccmmddhhiisstt 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 lliitthhiisstt shell option
- causes the shell to save the command with embedded newlines instead of
+ 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 lliitthhiisstt shell option
+ causes the shell to save the command with embedded newlines instead of
semicolons. See the description of the sshhoopptt builtin below under SSHHEELLLL
BBUUIILLTTIINN CCOOMMMMAANNDDSS for information on setting and unsetting shell
options.
HHIISSTTOORRYY EEXXPPAANNSSIIOONN
- The shell supports a history expansion feature that is similar to the
- history expansion in ccsshh.. This section describes what syntax features
- are available. This feature is enabled by default for interactive
+ The shell supports a history expansion feature that is similar to the
+ history expansion in ccsshh.. This section describes what syntax features
+ are available. This feature is enabled by default for interactive
shells, and can be disabled using the ++HH option to the sseett builtin com-
mand (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). Non-interactive shells do not
perform history expansion by default.
History expansions introduce words from the history list into the input
- stream, making it easy to repeat commands, insert the arguments to a
+ 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.
- History expansion is performed immediately after a complete line is
- read, before the shell breaks it into words. It takes place in two
- parts. The first is to determine which line from the history list to
+ History expansion is performed immediately after a complete line is
+ read, before the shell breaks it into words. It takes place in two
+ parts. The first is to determine which line from the history list to
use during substitution. The second is to select portions of that line
for inclusion into the current one. The line selected from the history
- is the _e_v_e_n_t, and the portions of that line that are acted upon are
- _w_o_r_d_s. Various _m_o_d_i_f_i_e_r_s are available to manipulate the selected
+ is the _e_v_e_n_t, and the portions of that line that are acted upon are
+ _w_o_r_d_s. Various _m_o_d_i_f_i_e_r_s are available to manipulate the selected
words. The line is broken into words in the same fashion as when read-
- ing input, so that several _m_e_t_a_c_h_a_r_a_c_t_e_r-separated words surrounded by
- quotes are considered one word. History expansions are introduced by
- the appearance of the history expansion character, which is !! by
- default. Only backslash (\\) and single quotes can quote the history
+ ing input, so that several _m_e_t_a_c_h_a_r_a_c_t_e_r-separated words surrounded by
+ quotes are considered one word. History expansions are introduced by
+ the appearance of the history expansion character, which is !! by
+ default. Only backslash (\\) and single quotes can quote the history
expansion character.
- Several characters inhibit history expansion if found immediately fol-
- lowing the history expansion character, even if it is unquoted: space,
- tab, newline, carriage return, and ==. If the eexxttgglloobb shell option is
+ Several characters inhibit history expansion if found immediately fol-
+ lowing the history expansion character, even if it is unquoted: space,
+ tab, newline, carriage return, and ==. If the eexxttgglloobb shell option is
enabled, (( will also inhibit expansion.
- Several shell options settable with the sshhoopptt builtin may be used to
- tailor the behavior of history expansion. If the hhiissttvveerriiffyy shell
+ Several shell options settable with the sshhoopptt builtin may be used to
+ tailor the behavior of history expansion. If the hhiissttvveerriiffyy shell
option is enabled (see the description of the sshhoopptt builtin below), and
- rreeaaddlliinnee is being used, history substitutions are not immediately
- passed to the shell parser. Instead, the expanded line is reloaded
+ rreeaaddlliinnee is being used, history substitutions are not immediately
+ passed to the shell parser. Instead, the expanded line is reloaded
into the rreeaaddlliinnee editing buffer for further modification. If rreeaaddlliinnee
- is being used, and the hhiissttrreeeeddiitt shell option is enabled, a failed
- history substitution will be reloaded into the rreeaaddlliinnee editing buffer
- for correction. The --pp option to the hhiissttoorryy builtin command may be
- used to see what a history expansion will do before using it. The --ss
+ is being used, and the hhiissttrreeeeddiitt shell option is enabled, a failed
+ history substitution will be reloaded into the rreeaaddlliinnee editing buffer
+ for correction. The --pp option to the hhiissttoorryy builtin command may be
+ used to see what a history expansion will do before using it. The --ss
option to the hhiissttoorryy builtin may be used to add commands to the end of
- the history list without actually executing them, so that they are
+ the history list without actually executing them, so that they are
available for subsequent recall.
- The shell allows control of the various characters used by the history
+ The shell allows control of the various characters used by the history
expansion mechanism (see the description of hhiissttcchhaarrss above under SShheellll
- VVaarriiaabblleess). The shell uses the history comment character to mark his-
+ VVaarriiaabblleess). The shell uses the history comment character to mark his-
tory timestamps when writing the history file.
EEvveenntt DDeessiiggnnaattoorrss
- An event designator is a reference to a command line entry in the his-
- tory list. Unless the reference is absolute, events are relative to
+ An event designator is a reference to a command line entry in the his-
+ tory list. Unless the reference is absolute, events are relative to
the current position in the history list.
- !! Start a history substitution, except when followed by a bbllaannkk,
- newline, carriage return, = or ( (when the eexxttgglloobb shell option
+ !! Start a history substitution, except when followed by a bbllaannkk,
+ newline, carriage return, = or ( (when the eexxttgglloobb shell option
is enabled using the sshhoopptt builtin).
!!_n Refer to command line _n.
!!--_n Refer to the current command minus _n.
!!!! Refer to the previous command. This is a synonym for `!-1'.
!!_s_t_r_i_n_g
- Refer to the most recent command preceding the current position
+ Refer to the most recent command preceding the current position
in the history list starting with _s_t_r_i_n_g.
!!??_s_t_r_i_n_g[[??]]
- Refer to the most recent command preceding the current postition
- in the history list containing _s_t_r_i_n_g. The trailing ?? may be
+ Refer to the most recent command preceding the current position
+ in the history list containing _s_t_r_i_n_g. The trailing ?? may be
omitted if _s_t_r_i_n_g is followed immediately by a newline.
^^_s_t_r_i_n_g_1^^_s_t_r_i_n_g_2^^
- Quick substitution. Repeat the previous command, replacing
- _s_t_r_i_n_g_1 with _s_t_r_i_n_g_2. Equivalent to ``!!:s/_s_t_r_i_n_g_1/_s_t_r_i_n_g_2/''
+ Quick substitution. Repeat the previous command, replacing
+ _s_t_r_i_n_g_1 with _s_t_r_i_n_g_2. Equivalent to ``!!:s/_s_t_r_i_n_g_1/_s_t_r_i_n_g_2/''
(see MMooddiiffiieerrss below).
!!## The entire command line typed so far.
WWoorrdd DDeessiiggnnaattoorrss
- Word designators are used to select desired words from the event. A ::
- separates the event specification from the word designator. It may be
- omitted if the word designator begins with a ^^, $$, **, --, or %%. 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 sepa-
+ Word designators are used to select desired words from the event. A ::
+ separates the event specification from the word designator. It may be
+ omitted if the word designator begins with a ^^, $$, **, --, or %%. Words
+ are numbered from the beginning of the line, with the first word being
+ denoted by 0 (zero). Words are inserted into the current line sepa-
rated by single spaces.
00 ((zzeerroo))
@@ -3685,17 +3706,17 @@ HHIISSTTOORRYY EEXXPPAANNSSIIOONN
$$ The last argument.
%% The word matched by the most recent `?_s_t_r_i_n_g?' search.
_x--_y A range of words; `-_y' abbreviates `0-_y'.
- ** All of the words but the zeroth. This is a synonym for `_1_-_$'.
- It is not an error to use ** if there is just one word in the
+ ** All of the words but the zeroth. This is a synonym for `_1_-_$'.
+ It is not an error to use ** if there is just one word in the
event; the empty string is returned in that case.
xx** Abbreviates _x_-_$.
xx-- Abbreviates _x_-_$ like xx**, but omits the last word.
- If a word designator is supplied without an event specification, the
+ If a word designator is supplied without an event specification, the
previous command is used as the event.
MMooddiiffiieerrss
- After the optional word designator, there may appear a sequence of one
+ After the optional word designator, there may appear a sequence of one
or more of the following modifiers, each preceded by a `:'.
hh Remove a trailing filename component, leaving only the head.
@@ -3704,104 +3725,104 @@ HHIISSTTOORRYY EEXXPPAANNSSIIOONN
ee Remove all but the trailing suffix.
pp Print the new command but do not execute it.
qq Quote the substituted words, escaping further substitutions.
- xx Quote the substituted words as with qq, but break into words at
+ xx Quote the substituted words as with qq, but break into words at
bbllaannkkss and newlines.
ss//_o_l_d//_n_e_w//
- Substitute _n_e_w for the first occurrence of _o_l_d in the event
- line. Any delimiter can be used in place of /. The final
- delimiter is optional if it is the last character of the event
- line. The delimiter may be quoted in _o_l_d and _n_e_w with a single
- backslash. If & appears in _n_e_w, it is replaced by _o_l_d. A sin-
- gle backslash will quote the &. If _o_l_d is null, it is set to
- the last _o_l_d substituted, or, if no previous history substitu-
+ Substitute _n_e_w for the first occurrence of _o_l_d in the event
+ line. Any delimiter can be used in place of /. The final
+ delimiter is optional if it is the last character of the event
+ line. The delimiter may be quoted in _o_l_d and _n_e_w with a single
+ backslash. If & appears in _n_e_w, it is replaced by _o_l_d. A sin-
+ gle backslash will quote the &. If _o_l_d is null, it is set to
+ the last _o_l_d substituted, or, if no previous history substitu-
tions took place, the last _s_t_r_i_n_g in a !!??_s_t_r_i_n_g[[??]] search.
&& Repeat the previous substitution.
gg Cause changes to be applied over the entire event line. This is
- used in conjunction with `::ss' (e.g., `::ggss//_o_l_d//_n_e_w//') or `::&&'.
- If used with `::ss', any delimiter can be used in place of /, and
- the final delimiter is optional if it is the last character of
+ used in conjunction with `::ss' (e.g., `::ggss//_o_l_d//_n_e_w//') or `::&&'.
+ If used with `::ss', any delimiter can be used in place of /, and
+ the final delimiter is optional if it is the last character of
the event line. An aa may be used as a synonym for gg.
- GG Apply the following `ss' modifier once to each word in the event
+ GG Apply the following `ss' modifier once to each word in the event
line.
SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
Unless otherwise noted, each builtin command documented in this section
as accepting options preceded by -- accepts ---- to signify the end of the
- options. The ::, ttrruuee, ffaallssee, and tteesstt builtins do not accept options
+ options. The ::, ttrruuee, ffaallssee, and tteesstt builtins do not accept options
and do not treat ---- specially. The eexxiitt, llooggoouutt, bbrreeaakk, ccoonnttiinnuuee, lleett,
- and sshhiifftt builtins accept and process arguments beginning with -- with-
- out requiring ----. Other builtins that accept arguments but are not
- specified as accepting options interpret arguments beginning with -- as
+ and sshhiifftt builtins accept and process arguments beginning with -- with-
+ out requiring ----. Other builtins that accept arguments but are not
+ specified as accepting options interpret arguments beginning with -- as
invalid options and require ---- to prevent this interpretation.
:: [_a_r_g_u_m_e_n_t_s]
- No effect; the command does nothing beyond expanding _a_r_g_u_m_e_n_t_s
- and performing any specified redirections. A zero exit code is
+ No effect; the command does nothing beyond expanding _a_r_g_u_m_e_n_t_s
+ and performing any specified redirections. A zero exit code is
returned.
.. _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s]
ssoouurrccee _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s]
- Read and execute commands from _f_i_l_e_n_a_m_e in the current shell
- environment and return the exit status of the last command exe-
- cuted from _f_i_l_e_n_a_m_e. If _f_i_l_e_n_a_m_e does not contain a slash,
- filenames in PPAATTHH are used to find the directory containing
+ Read and execute commands from _f_i_l_e_n_a_m_e in the current shell
+ environment and return the exit status of the last command exe-
+ cuted from _f_i_l_e_n_a_m_e. If _f_i_l_e_n_a_m_e does not contain a slash,
+ filenames in PPAATTHH are used to find the directory containing
_f_i_l_e_n_a_m_e. The file searched for in PPAATTHH need not be executable.
- When bbaasshh is not in _p_o_s_i_x _m_o_d_e, the current directory is
- searched if no file is found in PPAATTHH. If the ssoouurrcceeppaatthh option
- to the sshhoopptt builtin command is turned off, the PPAATTHH is not
- searched. If any _a_r_g_u_m_e_n_t_s are supplied, they become the posi-
- tional parameters when _f_i_l_e_n_a_m_e is executed. Otherwise the
- positional parameters are unchanged. The return status is the
- status of the last command exited within the script (0 if no
- commands are executed), and false if _f_i_l_e_n_a_m_e is not found or
+ When bbaasshh is not in _p_o_s_i_x _m_o_d_e, the current directory is
+ searched if no file is found in PPAATTHH. If the ssoouurrcceeppaatthh option
+ to the sshhoopptt builtin command is turned off, the PPAATTHH is not
+ searched. If any _a_r_g_u_m_e_n_t_s are supplied, they become the posi-
+ tional parameters when _f_i_l_e_n_a_m_e is executed. Otherwise the
+ positional parameters are unchanged. The return status is the
+ status of the last command exited within the script (0 if no
+ commands are executed), and false if _f_i_l_e_n_a_m_e is not found or
cannot be read.
aalliiaass [--pp] [_n_a_m_e[=_v_a_l_u_e] ...]
AAlliiaass with no arguments or with the --pp option prints the list of
- aliases in the form aalliiaass _n_a_m_e=_v_a_l_u_e on standard output. When
- arguments are supplied, an alias is defined for each _n_a_m_e whose
+ aliases in the form aalliiaass _n_a_m_e=_v_a_l_u_e on standard output. When
+ arguments are supplied, an alias is defined for each _n_a_m_e whose
_v_a_l_u_e is given. A trailing space in _v_a_l_u_e causes the next word
to be checked for alias substitution when the alias is expanded.
- For each _n_a_m_e in the argument list for which no _v_a_l_u_e is sup-
- plied, the name and value of the alias is printed. AAlliiaass
- returns true unless a _n_a_m_e is given for which no alias has been
+ For each _n_a_m_e in the argument list for which no _v_a_l_u_e is sup-
+ plied, the name and value of the alias is printed. AAlliiaass
+ returns true unless a _n_a_m_e is given for which no alias has been
defined.
bbgg [_j_o_b_s_p_e_c ...]
- Resume each suspended job _j_o_b_s_p_e_c in the background, as if it
+ Resume each suspended job _j_o_b_s_p_e_c in the background, as if it
had been started with &&. If _j_o_b_s_p_e_c is not present, the shell's
- notion of the _c_u_r_r_e_n_t _j_o_b is used. bbgg _j_o_b_s_p_e_c returns 0 unless
- run when job control is disabled or, when run with job control
- enabled, any specified _j_o_b_s_p_e_c was not found or was started
+ notion of the _c_u_r_r_e_n_t _j_o_b is used. bbgg _j_o_b_s_p_e_c returns 0 unless
+ run when job control is disabled or, when run with job control
+ enabled, any specified _j_o_b_s_p_e_c was not found or was started
without job control.
- bbiinndd [--mm _k_e_y_m_a_p] [--llppssvvPPSSVV]
+ bbiinndd [--mm _k_e_y_m_a_p] [--llppssvvPPSSVVXX]
bbiinndd [--mm _k_e_y_m_a_p] [--qq _f_u_n_c_t_i_o_n] [--uu _f_u_n_c_t_i_o_n] [--rr _k_e_y_s_e_q]
bbiinndd [--mm _k_e_y_m_a_p] --ff _f_i_l_e_n_a_m_e
bbiinndd [--mm _k_e_y_m_a_p] --xx _k_e_y_s_e_q:_s_h_e_l_l_-_c_o_m_m_a_n_d
bbiinndd [--mm _k_e_y_m_a_p] _k_e_y_s_e_q:_f_u_n_c_t_i_o_n_-_n_a_m_e
bbiinndd _r_e_a_d_l_i_n_e_-_c_o_m_m_a_n_d
- Display current rreeaaddlliinnee key and function bindings, bind a key
- sequence to a rreeaaddlliinnee function or macro, or set a rreeaaddlliinnee
- variable. Each non-option argument is a command as it would
- appear in _._i_n_p_u_t_r_c, but each binding or command must be passed
- as a separate argument; e.g., '"\C-x\C-r": re-read-init-file'.
+ Display current rreeaaddlliinnee key and function bindings, bind a key
+ sequence to a rreeaaddlliinnee function or macro, or set a rreeaaddlliinnee
+ variable. Each non-option argument is a command as it would
+ appear in _._i_n_p_u_t_r_c, but each binding or command must be passed
+ as a separate argument; e.g., '"\C-x\C-r": re-read-init-file'.
Options, if supplied, have the following meanings:
--mm _k_e_y_m_a_p
Use _k_e_y_m_a_p as the keymap to be affected by the subsequent
bindings. Acceptable _k_e_y_m_a_p names are _e_m_a_c_s_, _e_m_a_c_s_-_s_t_a_n_-
- _d_a_r_d_, _e_m_a_c_s_-_m_e_t_a_, _e_m_a_c_s_-_c_t_l_x_, _v_i_, _v_i_-_m_o_v_e_, _v_i_-_c_o_m_m_a_n_d,
- and _v_i_-_i_n_s_e_r_t. _v_i is equivalent to _v_i_-_c_o_m_m_a_n_d; _e_m_a_c_s is
+ _d_a_r_d_, _e_m_a_c_s_-_m_e_t_a_, _e_m_a_c_s_-_c_t_l_x_, _v_i_, _v_i_-_m_o_v_e_, _v_i_-_c_o_m_m_a_n_d,
+ and _v_i_-_i_n_s_e_r_t. _v_i is equivalent to _v_i_-_c_o_m_m_a_n_d; _e_m_a_c_s is
equivalent to _e_m_a_c_s_-_s_t_a_n_d_a_r_d.
--ll List the names of all rreeaaddlliinnee functions.
- --pp Display rreeaaddlliinnee function names and bindings in such a
+ --pp Display rreeaaddlliinnee function names and bindings in such a
way that they can be re-read.
--PP List current rreeaaddlliinnee function names and bindings.
- --ss Display rreeaaddlliinnee key sequences bound to macros and the
- strings they output in such a way that they can be re-
+ --ss Display rreeaaddlliinnee key sequences bound to macros and the
+ strings they output in such a way that they can be re-
read.
- --SS Display rreeaaddlliinnee key sequences bound to macros and the
+ --SS Display rreeaaddlliinnee key sequences bound to macros and the
strings they output.
- --vv Display rreeaaddlliinnee variable names and values in such a way
+ --vv Display rreeaaddlliinnee variable names and values in such a way
that they can be re-read.
--VV List current rreeaaddlliinnee variable names and values.
--ff _f_i_l_e_n_a_m_e
@@ -3813,157 +3834,170 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
--rr _k_e_y_s_e_q
Remove any current binding for _k_e_y_s_e_q.
--xx _k_e_y_s_e_q::_s_h_e_l_l_-_c_o_m_m_a_n_d
- Cause _s_h_e_l_l_-_c_o_m_m_a_n_d to be executed whenever _k_e_y_s_e_q is
- entered. When _s_h_e_l_l_-_c_o_m_m_a_n_d is executed, the shell sets
- the RREEAADDLLIINNEE__LLIINNEE variable to the contents of the rreeaadd--
- lliinnee line buffer and the RREEAADDLLIINNEE__PPOOIINNTT variable to the
+ Cause _s_h_e_l_l_-_c_o_m_m_a_n_d to be executed whenever _k_e_y_s_e_q is
+ entered. When _s_h_e_l_l_-_c_o_m_m_a_n_d is executed, the shell sets
+ the RREEAADDLLIINNEE__LLIINNEE variable to the contents of the rreeaadd--
+ lliinnee line buffer and the RREEAADDLLIINNEE__PPOOIINNTT variable to the
current location of the insertion point. If the executed
- command changes the value of RREEAADDLLIINNEE__LLIINNEE or RREEAADD--
- LLIINNEE__PPOOIINNTT, those new values will be reflected in the
+ command changes the value of RREEAADDLLIINNEE__LLIINNEE or RREEAADD--
+ LLIINNEE__PPOOIINNTT, those new values will be reflected in the
editing state.
+ --XX List all key sequences bound to shell commands and the
+ associated commands in a format that can be reused as
+ input.
- The return value is 0 unless an unrecognized option is given or
+ The return value is 0 unless an unrecognized option is given or
an error occurred.
bbrreeaakk [_n]
- Exit from within a ffoorr, wwhhiillee, uunnttiill, or sseelleecctt loop. If _n is
- specified, break _n levels. _n must be >= 1. If _n is greater
- than the number of enclosing loops, all enclosing loops are
- exited. The return value is 0 unless _n is not greater than or
+ Exit from within a ffoorr, wwhhiillee, uunnttiill, or sseelleecctt loop. If _n is
+ specified, break _n levels. _n must be >= 1. If _n is greater
+ than the number of enclosing loops, all enclosing loops are
+ exited. The return value is 0 unless _n is not greater than or
equal to 1.
bbuuiillttiinn _s_h_e_l_l_-_b_u_i_l_t_i_n [_a_r_g_u_m_e_n_t_s]
- Execute the specified shell builtin, passing it _a_r_g_u_m_e_n_t_s, and
+ Execute the specified shell builtin, passing it _a_r_g_u_m_e_n_t_s, and
return its exit status. This is useful when defining a function
- whose name is the same as a shell builtin, retaining the func-
+ whose name is the same as a shell builtin, retaining the func-
tionality of the builtin within the function. The ccdd builtin is
- commonly redefined this way. The return status is false if
+ commonly redefined this way. The return status is false if
_s_h_e_l_l_-_b_u_i_l_t_i_n is not a shell builtin command.
ccaalllleerr [_e_x_p_r]
Returns the context of any active subroutine call (a shell func-
tion or a script executed with the .. or ssoouurrccee builtins). With-
out _e_x_p_r, ccaalllleerr displays the line number and source filename of
- the current subroutine call. If a non-negative integer is sup-
+ the current subroutine call. If a non-negative integer is sup-
plied as _e_x_p_r, ccaalllleerr 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.
- The return value is 0 unless the shell is not executing a sub-
- routine call or _e_x_p_r does not correspond to a valid position in
+ 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.
+ The return value is 0 unless the shell is not executing a sub-
+ routine call or _e_x_p_r does not correspond to a valid position in
the call stack.
ccdd [--LL|[--PP [--ee]]] [_d_i_r]
- Change the current directory to _d_i_r. The variable HHOOMMEE is the
- default _d_i_r. The variable CCDDPPAATTHH defines the search path for
- the directory containing _d_i_r. Alternative directory names in
- CCDDPPAATTHH are separated by a colon (:). A null directory name in
- CCDDPPAATTHH is the same as the current directory, i.e., ``..''. If
- _d_i_r begins with a slash (/), then CCDDPPAATTHH is not used. The --PP
- option says to use the physical directory structure instead of
- following symbolic links (see also the --PP option to the sseett
- builtin command); the --LL option forces symbolic links to be fol-
- lowed. If the --ee option is supplied with --PP, and the current
- working directory cannot be successfully determined after a suc-
- cessful directory change, ccdd will return an unsuccessful status.
- An argument of -- is converted to $$OOLLDDPPWWDD before the directory
- change is attempted. If a non-empty directory name from CCDDPPAATTHH
- is used, or if -- is the first argument, and the directory change
- is successful, the absolute pathname of the new working direc-
- tory is written to the standard output. The return value is
- true if the directory was successfully changed; false otherwise.
+ Change the current directory to _d_i_r. if _d_i_r is not supplied,
+ the value of the HHOOMMEE shell variable is the default. Any addi-
+ tional arguments following _d_i_r are ignored. The variable CCDDPPAATTHH
+ defines the search path for the directory containing _d_i_r: each
+ directory name in CCDDPPAATTHH is searched for _d_i_r. Alternative
+ directory names in CCDDPPAATTHH are separated by a colon (:). A null
+ directory name in CCDDPPAATTHH is the same as the current directory,
+ i.e., ``..''. If _d_i_r begins with a slash (/), then CCDDPPAATTHH is not
+ used. The --PP option causes ccdd to use the physical directory
+ structure by resolving symbolic links while traversing _d_i_r and
+ before processing instances of _._. in _d_i_r (see also the --PP option
+ to the sseett builtin command); the --LL option forces symbolic links
+ to be followed by resolving the link after processing instances
+ of _._. in _d_i_r. If _._. appears in _d_i_r, it is processed by removing
+ the immediately previous pathname component from _d_i_r, back to a
+ slash or the beginning of _d_i_r. If the --ee option is supplied
+ with --PP, and the current working directory cannot be success-
+ fully determined after a successful directory change, ccdd will
+ return an unsuccessful status. An argument of -- is converted to
+ $$OOLLDDPPWWDD before the directory change is attempted. If a non-
+ empty directory name from CCDDPPAATTHH is used, or if -- is the first
+ argument, and the directory change is successful, the absolute
+ pathname of the new working directory is written to the standard
+ output. The return value is true if the directory was success-
+ fully changed; false otherwise.
ccoommmmaanndd [--ppVVvv] _c_o_m_m_a_n_d [_a_r_g ...]
- Run _c_o_m_m_a_n_d with _a_r_g_s suppressing the normal shell function
- lookup. Only builtin commands or commands found in the PPAATTHH are
- executed. If the --pp option is given, the search for _c_o_m_m_a_n_d is
- performed using a default value for PPAATTHH that is guaranteed to
- find all of the standard utilities. If either the --VV or --vv
+ Run _c_o_m_m_a_n_d with _a_r_g_s suppressing the normal shell function
+ lookup. Only builtin commands or commands found in the PPAATTHH are
+ executed. If the --pp option is given, the search for _c_o_m_m_a_n_d is
+ performed using a default value for PPAATTHH that is guaranteed to
+ find all of the standard utilities. If either the --VV or --vv
option is supplied, a description of _c_o_m_m_a_n_d is printed. The --vv
- option causes a single word indicating the command or filename
+ option causes a single word indicating the command or filename
used to invoke _c_o_m_m_a_n_d to be displayed; the --VV option produces a
- more verbose description. If the --VV or --vv option is supplied,
- the exit status is 0 if _c_o_m_m_a_n_d was found, and 1 if not. If
+ more verbose description. If the --VV or --vv option is supplied,
+ the exit status is 0 if _c_o_m_m_a_n_d was found, and 1 if not. If
neither option is supplied and an error occurred or _c_o_m_m_a_n_d can-
- not be found, the exit status is 127. Otherwise, the exit sta-
+ not be found, the exit status is 127. Otherwise, the exit sta-
tus of the ccoommmmaanndd builtin is the exit status of _c_o_m_m_a_n_d.
ccoommppggeenn [_o_p_t_i_o_n] [_w_o_r_d]
- Generate possible completion matches for _w_o_r_d according to the
- _o_p_t_i_o_ns, which may be any option accepted by the ccoommpplleettee
- builtin with the exception of --pp and --rr, and write the matches
- to the standard output. When using the --FF or --CC options, the
- various shell variables set by the programmable completion
+ Generate possible completion matches for _w_o_r_d according to the
+ _o_p_t_i_o_ns, which may be any option accepted by the ccoommpplleettee
+ builtin with the exception of --pp and --rr, and write the matches
+ to the standard output. When using the --FF or --CC options, the
+ various shell variables set by the programmable completion
facilities, while available, will not have useful values.
- The matches will be generated in the same way as if the pro-
- grammable completion code had generated them directly from a
+ The matches will be generated in the same way as if the pro-
+ grammable completion code had generated them directly from a
completion specification with the same flags. If _w_o_r_d is speci-
fied, only those completions matching _w_o_r_d will be displayed.
- The return value is true unless an invalid option is supplied,
+ The return value is true unless an invalid option is supplied,
or no matches were generated.
- ccoommpplleettee [--aabbccddeeffggjjkkssuuvv] [--oo _c_o_m_p_-_o_p_t_i_o_n] [--DDEE] [--AA _a_c_t_i_o_n] [--GG _g_l_o_b_-
+ ccoommpplleettee [--aabbccddeeffggjjkkssuuvv] [--oo _c_o_m_p_-_o_p_t_i_o_n] [--DDEE] [--AA _a_c_t_i_o_n] [--GG _g_l_o_b_-
_p_a_t] [--WW _w_o_r_d_l_i_s_t] [--FF _f_u_n_c_t_i_o_n] [--CC _c_o_m_m_a_n_d]
[--XX _f_i_l_t_e_r_p_a_t] [--PP _p_r_e_f_i_x] [--SS _s_u_f_f_i_x] _n_a_m_e [_n_a_m_e _._._.]
ccoommpplleettee --pprr [--DDEE] [_n_a_m_e ...]
- Specify how arguments to each _n_a_m_e should be completed. If the
- --pp option is supplied, or if no options are supplied, existing
- completion specifications are printed in a way that allows them
+ Specify how arguments to each _n_a_m_e should be completed. If the
+ --pp 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 --rr option removes a completion spec-
- ification for each _n_a_m_e, or, if no _n_a_m_es are supplied, all com-
+ ification for each _n_a_m_e, or, if no _n_a_m_es are supplied, all com-
pletion specifications. The --DD option indicates that the
- remaining options and actions should apply to the ``default''
- command completion; that is, completion attempted on a command
- for which no completion has previously been defined. The --EE
- option indicates that the remaining options and actions should
- apply to ``empty'' command completion; that is, completion
+ remaining options and actions should apply to the ``default''
+ command completion; that is, completion attempted on a command
+ for which no completion has previously been defined. The --EE
+ option indicates that the remaining options and actions should
+ apply to ``empty'' command completion; that is, completion
attempted on a blank line.
- The process of applying these completion specifications when
- word completion is attempted is described above under PPrroo--
+ The process of applying these completion specifications when
+ word completion is attempted is described above under PPrroo--
ggrraammmmaabbllee CCoommpplleettiioonn.
- Other options, if specified, have the following meanings. The
- arguments to the --GG, --WW, and --XX options (and, if necessary, the
- --PP and --SS options) should be quoted to protect them from expan-
+ Other options, if specified, have the following meanings. The
+ arguments to the --GG, --WW, and --XX options (and, if necessary, the
+ --PP and --SS options) should be quoted to protect them from expan-
sion before the ccoommpplleettee builtin is invoked.
--oo _c_o_m_p_-_o_p_t_i_o_n
- The _c_o_m_p_-_o_p_t_i_o_n controls several aspects of the comp-
- spec's behavior beyond the simple generation of comple-
+ The _c_o_m_p_-_o_p_t_i_o_n controls several aspects of the comp-
+ spec's behavior beyond the simple generation of comple-
tions. _c_o_m_p_-_o_p_t_i_o_n may be one of:
bbaasshhddeeffaauulltt
Perform the rest of the default bbaasshh completions
if the compspec generates no matches.
- ddeeffaauulltt Use readline's default filename completion if
+ ddeeffaauulltt Use readline's default filename completion if
the compspec generates no matches.
ddiirrnnaammeess
- Perform directory name completion if the comp-
+ Perform directory name completion if the comp-
spec generates no matches.
ffiilleennaammeess
- Tell readline that the compspec generates file-
- names, so it can perform any filename-specific
- processing (like adding a slash to directory
- names, quoting special characters, or suppress-
- ing trailing spaces). Intended to be used with
+ Tell readline that the compspec generates file-
+ names, so it can perform any filename-specific
+ processing (like adding a slash to directory
+ names, quoting special characters, or suppress-
+ ing trailing spaces). Intended to be used with
shell functions.
- nnoossppaaccee Tell readline not to append a space (the
- default) to words completed at the end of the
+ nnooqquuoottee Tell readline not to quote the completed words
+ if they are filenames (quoting filenames is the
+ default).
+ nnoossppaaccee Tell readline not to append a space (the
+ default) to words completed at the end of the
line.
pplluussddiirrss
- After any matches defined by the compspec are
- generated, directory name completion is
- attempted and any matches are added to the
+ 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.
--AA _a_c_t_i_o_n
- The _a_c_t_i_o_n may be one of the following to generate a
+ The _a_c_t_i_o_n may be one of the following to generate a
list of possible completions:
aalliiaass Alias names. May also be specified as --aa.
aarrrraayyvvaarr
Array variable names.
bbiinnddiinngg RReeaaddlliinnee key binding names.
- bbuuiillttiinn Names of shell builtin commands. May also be
+ bbuuiillttiinn Names of shell builtin commands. May also be
specified as --bb.
ccoommmmaanndd Command names. May also be specified as --cc.
ddiirreeccttoorryy
@@ -3971,7 +4005,7 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
ddiissaabblleedd
Names of disabled shell builtins.
eennaabblleedd Names of enabled shell builtins.
- eexxppoorrtt Names of exported shell variables. May also be
+ eexxppoorrtt Names of exported shell variables. May also be
specified as --ee.
ffiillee File names. May also be specified as --ff.
ffuunnccttiioonn
@@ -3980,17 +4014,17 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
hheellppttooppiicc
Help topics as accepted by the hheellpp builtin.
hhoossttnnaammee
- Hostnames, as taken from the file specified by
+ Hostnames, as taken from the file specified by
the HHOOSSTTFFIILLEE shell variable.
- jjoobb Job names, if job control is active. May also
+ jjoobb Job names, if job control is active. May also
be specified as --jj.
- kkeeyywwoorrdd Shell reserved words. May also be specified as
+ kkeeyywwoorrdd Shell reserved words. May also be specified as
--kk.
rruunnnniinngg Names of running jobs, if job control is active.
sseerrvviiccee Service names. May also be specified as --ss.
- sseettoopptt Valid arguments for the --oo option to the sseett
+ sseettoopptt Valid arguments for the --oo option to the sseett
builtin.
- sshhoopptt Shell option names as accepted by the sshhoopptt
+ sshhoopptt Shell option names as accepted by the sshhoopptt
builtin.
ssiiggnnaall Signal names.
ssttooppppeedd Names of stopped jobs, if job control is active.
@@ -3999,13 +4033,18 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
Names of all shell variables. May also be spec-
ified as --vv.
--CC _c_o_m_m_a_n_d
- _c_o_m_m_a_n_d is executed in a subshell environment, and its
+ _c_o_m_m_a_n_d is executed in a subshell environment, and its
output is used as the possible completions.
--FF _f_u_n_c_t_i_o_n
- The shell function _f_u_n_c_t_i_o_n is executed in the current
- shell environment. When it finishes, the possible com-
- pletions are retrieved from the value of the CCOOMMPPRREEPPLLYY
- array variable.
+ The shell function _f_u_n_c_t_i_o_n is executed in the current
+ shell environment. When the function is executed, the
+ first argument ($$11) is the name of the command whose
+ arguments are being completed, the second argument ($$22)
+ is the word being completed, and the third argument ($$33)
+ is the word preceding the word being completed on the
+ current command line. When it finishes, the possible
+ completions are retrieved from the value of the CCOOMMPPRREE--
+ PPLLYY array variable.
--GG _g_l_o_b_p_a_t
The pathname expansion pattern _g_l_o_b_p_a_t is expanded to
generate the possible completions.
@@ -4670,91 +4709,92 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
If no _n_a_m_e_s are supplied, the line read is assigned to the vari-
able RREEPPLLYY. The return code is zero, unless end-of-file is
encountered, rreeaadd times out (in which case the return code is
- greater than 128), or an invalid file descriptor is supplied as
- the argument to --uu.
+ greater than 128), a variable assignment error (such as assign-
+ ing to a readonly variable) occurs, or an invalid file descrip-
+ tor is supplied as the argument to --uu.
rreeaaddoonnllyy [--aaAAff] [--pp] [_n_a_m_e[=_w_o_r_d] ...]
- The given _n_a_m_e_s are marked readonly; the values of these _n_a_m_e_s
- may not be changed by subsequent assignment. If the --ff option
- is supplied, the functions corresponding to the _n_a_m_e_s are so
- marked. The --aa option restricts the variables to indexed
- arrays; the --AA option restricts the variables to associative
- arrays. If both options are supplied, --AA takes precedence. If
- no _n_a_m_e arguments are given, or if the --pp option is supplied, a
+ The given _n_a_m_e_s are marked readonly; the values of these _n_a_m_e_s
+ may not be changed by subsequent assignment. If the --ff option
+ is supplied, the functions corresponding to the _n_a_m_e_s are so
+ marked. The --aa option restricts the variables to indexed
+ arrays; the --AA option restricts the variables to associative
+ arrays. If both options are supplied, --AA takes precedence. If
+ no _n_a_m_e arguments are given, or if the --pp option is supplied, a
list of all readonly names is printed. The other options may be
- used to restrict the output to a subset of the set of readonly
- names. The --pp option causes output to be displayed in a format
- that may be reused as input. If a variable name is followed by
- =_w_o_r_d, the value of the variable is set to _w_o_r_d. The return
- status is 0 unless an invalid option is encountered, one of the
+ used to restrict the output to a subset of the set of readonly
+ names. The --pp option causes output to be displayed in a format
+ that may be reused as input. If a variable name is followed by
+ =_w_o_r_d, the value of the variable is set to _w_o_r_d. The return
+ status is 0 unless an invalid option is encountered, one of the
_n_a_m_e_s is not a valid shell variable name, or --ff is supplied with
a _n_a_m_e that is not a function.
rreettuurrnn [_n]
- Causes a function to stop executing and return the value speci-
- fied by _n to its caller. If _n is omitted, the return status is
- that of the last command executed in the function body. If
- rreettuurrnn is used outside a function, but during execution of a
- script by the .. (ssoouurrccee) command, it causes the shell to stop
- executing that script and return either _n or the exit status of
- the last command executed within the script as the exit status
- of the script. If _n is supplied, the return value is its least
- significant 8 bits. The return status is non-zero if rreettuurrnn is
- supplied a non-numeric argument, or is used outside a function
- and not during execution of a script by .. or ssoouurrccee. Any com-
- mand associated with the RREETTUURRNN trap is executed before execu-
+ Causes a function to stop executing and return the value speci-
+ fied by _n to its caller. If _n is omitted, the return status is
+ that of the last command executed in the function body. If
+ rreettuurrnn is used outside a function, but during execution of a
+ script by the .. (ssoouurrccee) command, it causes the shell to stop
+ executing that script and return either _n or the exit status of
+ the last command executed within the script as the exit status
+ of the script. If _n is supplied, the return value is its least
+ significant 8 bits. The return status is non-zero if rreettuurrnn is
+ supplied a non-numeric argument, or is used outside a function
+ and not during execution of a script by .. or ssoouurrccee. Any com-
+ mand associated with the RREETTUURRNN trap is executed before execu-
tion resumes after the function or script.
sseett [----aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [--oo _o_p_t_i_o_n_-_n_a_m_e] [_a_r_g ...]
sseett [++aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [++oo _o_p_t_i_o_n_-_n_a_m_e] [_a_r_g ...]
- Without options, the name and value of each shell variable are
+ Without options, the name and value of each shell variable are
displayed in a format that can be reused as input for setting or
resetting the currently-set variables. Read-only variables can-
- not be reset. In _p_o_s_i_x _m_o_d_e, only shell variables are listed.
- The output is sorted according to the current locale. When
- options are specified, they set or unset shell attributes. Any
- arguments remaining after option processing are treated as val-
+ not be reset. In _p_o_s_i_x _m_o_d_e, only shell variables are listed.
+ The output is sorted according to the current locale. When
+ options are specified, they set or unset shell attributes. Any
+ arguments remaining after option processing are treated as val-
ues for the positional parameters and are assigned, in order, to
- $$11, $$22, ...... $$_n. Options, if specified, have the following
+ $$11, $$22, ...... $$_n. Options, if specified, have the following
meanings:
- --aa Automatically mark variables and functions which are
- modified or created for export to the environment of
+ --aa Automatically mark variables and functions which are
+ modified or created for export to the environment of
subsequent commands.
- --bb Report the status of terminated background jobs immedi-
+ --bb Report the status of terminated background jobs immedi-
ately, rather than before the next primary prompt. This
is effective only when job control is enabled.
- --ee Exit immediately if a _p_i_p_e_l_i_n_e (which may consist of a
- single _s_i_m_p_l_e _c_o_m_m_a_n_d), a _l_i_s_t, or a _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d
- (see SSHHEELLLL GGRRAAMMMMAARR above), exits with a non-zero sta-
- tus. The shell does not exit if the command that fails
- is part of the command list immediately following a
- wwhhiillee or uunnttiill keyword, part of the test following the
- iiff or eelliiff reserved words, part of any command executed
- in a &&&& or |||| list except the command following the
- final &&&& or ||||, any command in a pipeline but the last,
- or if the command's return value is being inverted with
- !!. If a compound command other than a subshell returns
- a non-zero status because a command failed while --ee was
- being ignored, the shell does not exit. A trap on EERRRR,
+ --ee Exit immediately if a _p_i_p_e_l_i_n_e (which may consist of a
+ single _s_i_m_p_l_e _c_o_m_m_a_n_d), a _l_i_s_t, or a _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d
+ (see SSHHEELLLL GGRRAAMMMMAARR above), exits with a non-zero sta-
+ tus. The shell does not exit if the command that fails
+ is part of the command list immediately following a
+ wwhhiillee or uunnttiill keyword, part of the test following the
+ iiff or eelliiff reserved words, part of any command executed
+ in a &&&& or |||| list except the command following the
+ final &&&& or ||||, any command in a pipeline but the last,
+ or if the command's return value is being inverted with
+ !!. If a compound command other than a subshell returns
+ a non-zero status because a command failed while --ee was
+ being ignored, the shell does not exit. A trap on EERRRR,
if set, is executed before the shell exits. This option
applies to the shell environment and each subshell envi-
- ronment separately (see CCOOMMMMAANNDD EEXXEECCUUTTIIOONN EENNVVIIRROONNMMEENNTT
+ ronment separately (see CCOOMMMMAANNDD EEXXEECCUUTTIIOONN EENNVVIIRROONNMMEENNTT
above), and may cause subshells to exit before executing
all the commands in the subshell.
--ff Disable pathname expansion.
- --hh Remember the location of commands as they are looked up
+ --hh Remember the location of commands as they are looked up
for execution. This is enabled by default.
- --kk All arguments in the form of assignment statements are
- placed in the environment for a command, not just those
+ --kk All arguments in the form of assignment statements are
+ placed in the environment for a command, not just those
that precede the command name.
- --mm Monitor mode. Job control is enabled. This option is
- on by default for interactive shells on systems that
- support it (see JJOOBB CCOONNTTRROOLL above). All processes run
+ --mm Monitor mode. Job control is enabled. This option is
+ on by default for interactive shells on systems that
+ support it (see JJOOBB CCOONNTTRROOLL above). All processes run
in a separate process group. When a background job com-
pletes, the shell prints a line containing its exit sta-
tus.
--nn Read commands but do not execute them. This may be used
- to check a shell script for syntax errors. This is
+ to check a shell script for syntax errors. This is
ignored by interactive shells.
--oo _o_p_t_i_o_n_-_n_a_m_e
The _o_p_t_i_o_n_-_n_a_m_e can be one of the following:
@@ -4762,10 +4802,10 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
Same as --aa.
bbrraacceeeexxppaanndd
Same as --BB.
- eemmaaccss Use an emacs-style command line editing inter-
+ eemmaaccss Use an emacs-style command line editing inter-
face. This is enabled by default when the shell
is interactive, unless the shell is started with
- the ----nnooeeddiittiinngg option. This also affects the
+ the ----nnooeeddiittiinngg option. This also affects the
editing interface used for rreeaadd --ee.
eerrrreexxiitt Same as --ee.
eerrrrttrraaccee
@@ -4779,8 +4819,8 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
HHIISSTTOORRYY. This option is on by default in inter-
active shells.
iiggnnoorreeeeooff
- The effect is as if the shell command
- ``IGNOREEOF=10'' had been executed (see SShheellll
+ The effect is as if the shell command
+ ``IGNOREEOF=10'' had been executed (see SShheellll
VVaarriiaabblleess above).
kkeeyywwoorrdd Same as --kk.
mmoonniittoorr Same as --mm.
@@ -4795,330 +4835,330 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
pphhyyssiiccaall
Same as --PP.
ppiippeeffaaiill
- 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
+ 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.
- ppoossiixx Change the behavior of bbaasshh where the default
- operation differs from the POSIX standard to
+ ppoossiixx Change the behavior of bbaasshh where the default
+ operation differs from the POSIX standard to
match the standard (_p_o_s_i_x _m_o_d_e).
pprriivviilleeggeedd
Same as --pp.
vveerrbboossee Same as --vv.
- vvii Use a vi-style command line editing interface.
+ vvii Use a vi-style command line editing interface.
This also affects the editing interface used for
rreeaadd --ee.
xxttrraaccee Same as --xx.
If --oo is supplied with no _o_p_t_i_o_n_-_n_a_m_e, the values of the
- current options are printed. If ++oo is supplied with no
- _o_p_t_i_o_n_-_n_a_m_e, a series of sseett commands to recreate the
- current option settings is displayed on the standard
+ current options are printed. If ++oo is supplied with no
+ _o_p_t_i_o_n_-_n_a_m_e, a series of sseett commands to recreate the
+ current option settings is displayed on the standard
output.
- --pp Turn on _p_r_i_v_i_l_e_g_e_d mode. In this mode, the $$EENNVV and
- $$BBAASSHH__EENNVV files are not processed, shell functions are
- not inherited from the environment, and the SSHHEELLLLOOPPTTSS,
- BBAASSHHOOPPTTSS, CCDDPPAATTHH, and GGLLOOBBIIGGNNOORREE variables, if they
+ --pp Turn on _p_r_i_v_i_l_e_g_e_d mode. In this mode, the $$EENNVV and
+ $$BBAASSHH__EENNVV files are not processed, shell functions are
+ not inherited from the environment, and the SSHHEELLLLOOPPTTSS,
+ BBAASSHHOOPPTTSS, CCDDPPAATTHH, and GGLLOOBBIIGGNNOORREE variables, if they
appear in the environment, are ignored. If the shell is
- started with the effective user (group) id not equal to
- the real user (group) id, and the --pp option is not sup-
+ started with the effective user (group) id not equal to
+ the real user (group) id, and the --pp option is not sup-
plied, these actions are taken and the effective user id
- is set to the real user id. If the --pp option is sup-
- plied at startup, the effective user id is not reset.
- Turning this option off causes the effective user and
+ is set to the real user id. If the --pp option is sup-
+ plied 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.
--tt Exit after reading and executing one command.
--uu Treat unset variables and parameters other than the spe-
- cial parameters "@" and "*" as an error when performing
- parameter expansion. If expansion is attempted on an
- unset variable or parameter, the shell prints an error
- message, and, if not interactive, exits with a non-zero
+ cial parameters "@" and "*" as an error when performing
+ parameter expansion. If expansion is attempted on an
+ unset variable or parameter, the shell prints an error
+ message, and, if not interactive, exits with a non-zero
status.
--vv Print shell input lines as they are read.
- --xx After expanding each _s_i_m_p_l_e _c_o_m_m_a_n_d, ffoorr command, ccaassee
+ --xx After expanding each _s_i_m_p_l_e _c_o_m_m_a_n_d, ffoorr command, ccaassee
command, sseelleecctt command, or arithmetic ffoorr command, dis-
- play the expanded value of PPSS44, followed by the command
+ play the expanded value of PPSS44, followed by the command
and its expanded arguments or associated word list.
- --BB The shell performs brace expansion (see BBrraaccee EExxppaannssiioonn
+ --BB The shell performs brace expansion (see BBrraaccee EExxppaannssiioonn
above). This is on by default.
- --CC If set, bbaasshh does not overwrite an existing file with
- the >>, >>&&, and <<>> redirection operators. This may be
+ --CC If set, bbaasshh does not overwrite an existing file with
+ the >>, >>&&, and <<>> redirection operators. This may be
overridden when creating output files by using the redi-
rection operator >>|| instead of >>.
--EE If set, any trap on EERRRR is inherited by shell functions,
- command substitutions, and commands executed in a sub-
- shell environment. The EERRRR trap is normally not inher-
+ command substitutions, and commands executed in a sub-
+ shell environment. The EERRRR trap is normally not inher-
ited in such cases.
--HH Enable !! style history substitution. This option is on
by default when the shell is interactive.
- --PP If set, the shell does not follow symbolic links when
- executing commands such as ccdd that change the current
+ --PP If set, the shell does not resolve symbolic links when
+ executing commands such as ccdd that change the current
working directory. It uses the physical directory
structure instead. By default, bbaasshh follows the logical
- chain of directories when performing commands which
+ chain of directories when performing commands which
change the current directory.
- --TT If set, any traps on DDEEBBUUGG and RREETTUURRNN are inherited by
- shell functions, command substitutions, and commands
- executed in a subshell environment. The DDEEBBUUGG and
+ --TT If set, any traps on DDEEBBUUGG and RREETTUURRNN are inherited by
+ shell functions, command substitutions, and commands
+ executed in a subshell environment. The DDEEBBUUGG and
RREETTUURRNN traps are normally not inherited in such cases.
- ---- If no arguments follow this option, then the positional
+ ---- If no arguments follow this option, then the positional
parameters are unset. Otherwise, the positional parame-
- ters are set to the _a_r_gs, even if some of them begin
+ ters are set to the _a_r_gs, even if some of them begin
with a --.
- -- Signal the end of options, cause all remaining _a_r_gs to
+ -- Signal the end of options, cause all remaining _a_r_gs to
be assigned to the positional parameters. The --xx and --vv
options are turned off. If there are no _a_r_gs, the posi-
tional parameters remain unchanged.
- The options are off by default unless otherwise noted. Using +
- rather than - causes these options to be turned off. The
- options can also be specified as arguments to an invocation of
- the shell. The current set of options may be found in $$--. The
+ The options are off by default unless otherwise noted. Using +
+ rather than - causes these options to be turned off. The
+ options can also be specified as arguments to an invocation of
+ the shell. The current set of options may be found in $$--. The
return status is always true unless an invalid option is encoun-
tered.
sshhiifftt [_n]
- The positional parameters from _n+1 ... are renamed to $$11 ........
- Parameters represented by the numbers $$## down to $$##-_n+1 are
- unset. _n must be a non-negative number less than or equal to
- $$##. If _n is 0, no parameters are changed. If _n is not given,
- it is assumed to be 1. If _n is greater than $$##, the positional
- parameters are not changed. The return status is greater than
+ The positional parameters from _n+1 ... are renamed to $$11 ........
+ Parameters represented by the numbers $$## down to $$##-_n+1 are
+ unset. _n must be a non-negative number less than or equal to
+ $$##. If _n is 0, no parameters are changed. If _n is not given,
+ it is assumed to be 1. If _n is greater than $$##, the positional
+ parameters are not changed. The return status is greater than
zero if _n is greater than $$## or less than zero; otherwise 0.
sshhoopptt [--ppqqssuu] [--oo] [_o_p_t_n_a_m_e ...]
Toggle the values of variables controlling optional shell behav-
ior. With no options, or with the --pp option, a list of all set-
table options is displayed, with an indication of whether or not
- each is set. The --pp option causes output to be displayed in a
- form that may be reused as input. Other options have the fol-
+ each is set. The --pp option causes output to be displayed in a
+ form that may be reused as input. Other options have the fol-
lowing meanings:
--ss Enable (set) each _o_p_t_n_a_m_e.
--uu Disable (unset) each _o_p_t_n_a_m_e.
- --qq Suppresses normal output (quiet mode); the return status
+ --qq Suppresses normal output (quiet mode); the return status
indicates whether the _o_p_t_n_a_m_e is set or unset. If multi-
- ple _o_p_t_n_a_m_e arguments are given with --qq, the return sta-
- tus is zero if all _o_p_t_n_a_m_e_s are enabled; non-zero other-
+ ple _o_p_t_n_a_m_e arguments are given with --qq, the return sta-
+ tus is zero if all _o_p_t_n_a_m_e_s are enabled; non-zero other-
wise.
- --oo Restricts the values of _o_p_t_n_a_m_e to be those defined for
+ --oo Restricts the values of _o_p_t_n_a_m_e to be those defined for
the --oo option to the sseett builtin.
- If either --ss or --uu is used with no _o_p_t_n_a_m_e arguments, sshhoopptt
- shows only those options which are set or unset, respectively.
- Unless otherwise noted, the sshhoopptt options are disabled (unset)
+ If either --ss or --uu is used with no _o_p_t_n_a_m_e arguments, sshhoopptt
+ shows only those options which are set or unset, respectively.
+ Unless otherwise noted, the sshhoopptt options are disabled (unset)
by default.
- The return status when listing options is zero if all _o_p_t_n_a_m_e_s
- are enabled, non-zero otherwise. When setting or unsetting
- options, the return status is zero unless an _o_p_t_n_a_m_e is not a
+ The return status when listing options is zero if all _o_p_t_n_a_m_e_s
+ are enabled, non-zero otherwise. When setting or unsetting
+ options, the return status is zero unless an _o_p_t_n_a_m_e is not a
valid shell option.
The list of sshhoopptt options is:
- aauuttooccdd If set, a command name that is the name of a directory
- is executed as if it were the argument to the ccdd com-
+ aauuttooccdd If set, a command name that is the name of a directory
+ is executed as if it were the argument to the ccdd com-
mand. This option is only used by interactive shells.
ccddaabbllee__vvaarrss
- If set, an argument to the ccdd builtin command that is
- not a directory is assumed to be the name of a variable
+ If set, an argument to the ccdd builtin command that is
+ not a directory is assumed to be the name of a variable
whose value is the directory to change to.
ccddssppeellll If set, minor errors in the spelling of a directory com-
- ponent in a ccdd command will be corrected. The errors
+ ponent in a ccdd command will be corrected. The errors
checked for are transposed characters, a missing charac-
- ter, and one character too many. If a correction is
- found, the corrected filename is printed, and the com-
- mand proceeds. This option is only used by interactive
+ ter, and one character too many. If a correction is
+ found, the corrected filename is printed, and the com-
+ mand proceeds. This option is only used by interactive
shells.
cchheecckkhhaasshh
If set, bbaasshh checks that a command found in the hash ta-
- ble exists before trying to execute it. If a hashed
- command no longer exists, a normal path search is per-
+ ble exists before trying to execute it. If a hashed
+ command no longer exists, a normal path search is per-
formed.
cchheecckkjjoobbss
If set, bbaasshh lists the status of any stopped and running
- jobs before exiting an interactive shell. If any jobs
+ 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 JJOOBB CCOONNTTRROOLL above). The shell always postpones
+ second exit is attempted without an intervening command
+ (see JJOOBB CCOONNTTRROOLL above). The shell always postpones
exiting if any jobs are stopped.
cchheecckkwwiinnssiizzee
- If set, bbaasshh checks the window size after each command
- and, if necessary, updates the values of LLIINNEESS and CCOOLL--
+ If set, bbaasshh checks the window size after each command
+ and, if necessary, updates the values of LLIINNEESS and CCOOLL--
UUMMNNSS.
- ccmmddhhiisstt If set, bbaasshh attempts to save all lines of a multiple-
- line command in the same history entry. This allows
+ ccmmddhhiisstt If set, bbaasshh attempts to save all lines of a multiple-
+ line command in the same history entry. This allows
easy re-editing of multi-line commands.
ccoommppaatt3311
If set, bbaasshh changes its behavior to that of version 3.1
- with respect to quoted arguments to the [[[[ conditional
+ with respect to quoted arguments to the [[[[ conditional
command's ==~~ operator.
ccoommppaatt3322
If set, bbaasshh changes its behavior to that of version 3.2
- with respect to locale-specific string comparison when
- using the [[[[ conditional command's << and >> operators.
- Bash versions prior to bash-4.1 use ASCII collation and
- _s_t_r_c_m_p(3); bash-4.1 and later use the current locale's
+ with respect to locale-specific string comparison when
+ using the [[[[ conditional command's << and >> operators.
+ Bash versions prior to bash-4.1 use ASCII collation and
+ _s_t_r_c_m_p(3); bash-4.1 and later use the current locale's
collation sequence and _s_t_r_c_o_l_l(3).
ccoommppaatt4400
If set, bbaasshh changes its behavior to that of version 4.0
- with respect to locale-specific string comparison when
- using the [[[[ conditional command's << and >> operators
- (see previous item) and the effect of interrupting a
+ with respect to locale-specific string comparison when
+ using the [[[[ conditional command's << and >> operators
+ (see previous item) and the effect of interrupting a
command list.
ccoommppaatt4411
- If set, bbaasshh, when in posix mode, treats a single quote
- in a double-quoted parameter expansion as a special
- character. The single quotes must match (an even num-
- ber) and the characters between the single quotes are
- considered quoted. This is the behavior of posix mode
- through version 4.1. The default bash behavior remains
+ If set, bbaasshh, when in posix mode, treats a single quote
+ in a double-quoted parameter expansion as a special
+ character. The single quotes must match (an even num-
+ ber) and the characters between the single quotes are
+ considered quoted. This is the behavior of posix mode
+ through version 4.1. The default bash behavior remains
as in previous versions.
ccoommpplleettee__ffuullllqquuoottee
- If set, bbaasshh quotes all shell metacharacters in file-
- names and directory names when performing completion.
+ If set, bbaasshh quotes all shell metacharacters in file-
+ names and directory names when performing completion.
If not set, bbaasshh removes metacharacters such as the dol-
- lar sign from the set of characters that will be quoted
- in completed filenames when these metacharacters appear
- in shell variable references in words to be completed.
- This means that dollar signs in variable names that
- expand to directories will not be quoted; however, any
- dollar signs appearing in filenames will not be quoted,
- either. This is active only when bash is using back-
- slashes to quote completed filenames. This variable is
- set by default, which is the default bash behavior in
+ lar sign from the set of characters that will be quoted
+ in completed filenames when these metacharacters appear
+ in shell variable references in words to be completed.
+ This means that dollar signs in variable names that
+ expand to directories will not be quoted; however, any
+ dollar signs appearing in filenames will not be quoted,
+ either. This is active only when bash is using back-
+ slashes to quote completed filenames. This variable is
+ set by default, which is the default bash behavior in
versions through 4.2.
ddiirreexxppaanndd
- If set, bbaasshh replaces directory names with the results
- of word expansion when performing filename completion.
+ If set, bbaasshh replaces directory names with the results
+ of word expansion when performing filename completion.
This changes the contents of the readline editing
- buffer. If not set, bbaasshh attempts to preserve what the
+ buffer. If not set, bbaasshh attempts to preserve what the
user typed.
ddiirrssppeellll
- If set, bbaasshh attempts spelling correction on directory
- names during word completion if the directory name ini-
+ If set, bbaasshh attempts spelling correction on directory
+ names during word completion if the directory name ini-
tially supplied does not exist.
- ddoottgglloobb If set, bbaasshh includes filenames beginning with a `.' in
+ ddoottgglloobb If set, bbaasshh includes filenames beginning with a `.' in
the results of pathname expansion.
eexxeeccffaaiill
If set, a non-interactive shell will not exit if it can-
- not execute the file specified as an argument to the
- eexxeecc builtin command. An interactive shell does not
+ not execute the file specified as an argument to the
+ eexxeecc builtin command. An interactive shell does not
exit if eexxeecc fails.
eexxppaanndd__aalliiaasseess
- If set, aliases are expanded as described above under
+ If set, aliases are expanded as described above under
AALLIIAASSEESS. This option is enabled by default for interac-
tive shells.
eexxttddeebbuugg
- If set, behavior intended for use by debuggers is
+ If set, behavior intended for use by debuggers is
enabled:
11.. The --FF option to the ddeeccllaarree builtin displays the
source file name and line number corresponding to
each function name supplied as an argument.
- 22.. If the command run by the DDEEBBUUGG trap returns a
- non-zero value, the next command is skipped and
+ 22.. If the command run by the DDEEBBUUGG trap returns a
+ non-zero value, the next command is skipped and
not executed.
- 33.. If the command run by the DDEEBBUUGG trap returns a
- value of 2, and the shell is executing in a sub-
- routine (a shell function or a shell script exe-
- cuted by the .. or ssoouurrccee builtins), a call to
+ 33.. If the command run by the DDEEBBUUGG trap returns a
+ value of 2, and the shell is executing in a sub-
+ routine (a shell function or a shell script exe-
+ cuted by the .. or ssoouurrccee builtins), a call to
rreettuurrnn is simulated.
- 44.. BBAASSHH__AARRGGCC and BBAASSHH__AARRGGVV are updated as described
+ 44.. BBAASSHH__AARRGGCC and BBAASSHH__AARRGGVV are updated as described
in their descriptions above.
- 55.. Function tracing is enabled: command substitu-
+ 55.. Function tracing is enabled: command substitu-
tion, shell functions, and subshells invoked with
(( _c_o_m_m_a_n_d )) inherit the DDEEBBUUGG and RREETTUURRNN traps.
- 66.. Error tracing is enabled: command substitution,
- shell functions, and subshells invoked with ((
+ 66.. Error tracing is enabled: command substitution,
+ shell functions, and subshells invoked with ((
_c_o_m_m_a_n_d )) inherit the EERRRR trap.
eexxttgglloobb If set, the extended pattern matching features described
above under PPaatthhnnaammee EExxppaannssiioonn are enabled.
eexxttqquuoottee
- If set, $$'_s_t_r_i_n_g' and $$"_s_t_r_i_n_g" quoting is performed
- within $${{_p_a_r_a_m_e_t_e_r}} expansions enclosed in double
+ If set, $$'_s_t_r_i_n_g' and $$"_s_t_r_i_n_g" quoting is performed
+ within $${{_p_a_r_a_m_e_t_e_r}} expansions enclosed in double
quotes. This option is enabled by default.
ffaaiillgglloobb
- If set, patterns which fail to match filenames during
+ If set, patterns which fail to match filenames during
pathname expansion result in an expansion error.
ffoorrccee__ffiiggnnoorree
- If set, the suffixes specified by the FFIIGGNNOORREE shell
- variable cause words to be ignored when performing word
+ If set, the suffixes specified by the FFIIGGNNOORREE shell
+ variable cause words to be ignored when performing word
completion even if the ignored words are the only possi-
ble completions. See SSHHEELLLL VVAARRIIAABBLLEESS above for a
- description of FFIIGGNNOORREE. This option is enabled by
+ description of FFIIGGNNOORREE. This option is enabled by
default.
gglloobbaasscciiiirraannggeess
- If set, range expressions used in pattern matching (see
- PPaatttteerrnn MMaattcchhiinngg above) behave as if in the traditional
+ If set, range expressions used in pattern matching (see
+ PPaatttteerrnn MMaattcchhiinngg above) behave as if in the traditional
C locale when performing comparisons. That is, the cur-
- rent locale's collating sequence is not taken into
- account, so bb will not collate between AA and BB, and
- upper-case and lower-case ASCII characters will collate
+ rent locale's collating sequence is not taken into
+ account, so bb will not collate between AA and BB, and
+ upper-case and lower-case ASCII characters will collate
together.
gglloobbssttaarr
If set, the pattern **** used in a pathname expansion con-
- text will match all files and zero or more directories
- and subdirectories. If the pattern is followed by a //,
+ text will match all files and zero or more directories
+ and subdirectories. If the pattern is followed by a //,
only directories and subdirectories match.
ggnnuu__eerrrrffmmtt
If set, shell error messages are written in the standard
GNU error message format.
hhiissttaappppeenndd
- If set, the history list is appended to the file named
- by the value of the HHIISSTTFFIILLEE variable when the shell
+ If set, the history list is appended to the file named
+ by the value of the HHIISSTTFFIILLEE variable when the shell
exits, rather than overwriting the file.
hhiissttrreeeeddiitt
- If set, and rreeaaddlliinnee is being used, a user is given the
+ If set, and rreeaaddlliinnee is being used, a user is given the
opportunity to re-edit a failed history substitution.
hhiissttvveerriiffyy
- If set, and rreeaaddlliinnee is being used, the results of his-
- tory substitution are not immediately passed to the
- shell parser. Instead, the resulting line is loaded
+ If set, and rreeaaddlliinnee is being used, the results of his-
+ tory substitution are not immediately passed to the
+ shell parser. Instead, the resulting line is loaded
into the rreeaaddlliinnee editing buffer, allowing further modi-
fication.
hhoossttccoommpplleettee
If set, and rreeaaddlliinnee is being used, bbaasshh will attempt to
- perform hostname completion when a word containing a @@
- is being completed (see CCoommpplleettiinngg under RREEAADDLLIINNEE
+ perform hostname completion when a word containing a @@
+ is being completed (see CCoommpplleettiinngg under RREEAADDLLIINNEE
above). This is enabled by default.
hhuuppoonneexxiitt
If set, bbaasshh will send SSIIGGHHUUPP to all jobs when an inter-
active login shell exits.
iinntteerraaccttiivvee__ccoommmmeennttss
If set, allow a word beginning with ## to cause that word
- and all remaining characters on that line to be ignored
- in an interactive shell (see CCOOMMMMEENNTTSS above). This
+ and all remaining characters on that line to be ignored
+ in an interactive shell (see CCOOMMMMEENNTTSS above). This
option is enabled by default.
llaassttppiippee
- If set, and job control is not active, the shell runs
+ If set, and job control is not active, the shell runs
the last command of a pipeline not executed in the back-
ground in the current shell environment.
- lliitthhiisstt If set, and the ccmmddhhiisstt option is enabled, multi-line
+ lliitthhiisstt If set, and the ccmmddhhiisstt option is enabled, multi-line
commands are saved to the history with embedded newlines
rather than using semicolon separators where possible.
llooggiinn__sshheellll
- The shell sets this option if it is started as a login
- shell (see IINNVVOOCCAATTIIOONN above). The value may not be
+ The shell sets this option if it is started as a login
+ shell (see IINNVVOOCCAATTIIOONN above). The value may not be
changed.
mmaaiillwwaarrnn
- If set, and a file that bbaasshh is checking for mail has
- been accessed since the last time it was checked, the
- message ``The mail in _m_a_i_l_f_i_l_e has been read'' is dis-
+ If set, and a file that bbaasshh is checking for mail has
+ been accessed since the last time it was checked, the
+ message ``The mail in _m_a_i_l_f_i_l_e has been read'' is dis-
played.
nnoo__eemmppttyy__ccmmdd__ccoommpplleettiioonn
- If set, and rreeaaddlliinnee is being used, bbaasshh will not
+ If set, and rreeaaddlliinnee is being used, bbaasshh will not
attempt to search the PPAATTHH for possible completions when
completion is attempted on an empty line.
nnooccaasseegglloobb
- If set, bbaasshh matches filenames in a case-insensitive
+ If set, bbaasshh matches filenames in a case-insensitive
fashion when performing pathname expansion (see PPaatthhnnaammee
EExxppaannssiioonn above).
nnooccaasseemmaattcchh
- If set, bbaasshh matches patterns in a case-insensitive
+ If set, bbaasshh matches patterns in a case-insensitive
fashion when performing matching while executing ccaassee or
[[[[ conditional commands.
nnuullllgglloobb
- If set, bbaasshh allows patterns which match no files (see
- PPaatthhnnaammee EExxppaannssiioonn above) to expand to a null string,
+ If set, bbaasshh allows patterns which match no files (see
+ PPaatthhnnaammee EExxppaannssiioonn above) to expand to a null string,
rather than themselves.
pprrooggccoommpp
If set, the programmable completion facilities (see PPrroo--
@@ -5126,50 +5166,50 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
enabled by default.
pprroommppttvvaarrss
If set, prompt strings undergo parameter expansion, com-
- mand substitution, arithmetic expansion, and quote
- removal after being expanded as described in PPRROOMMPPTTIINNGG
+ mand substitution, arithmetic expansion, and quote
+ removal after being expanded as described in PPRROOMMPPTTIINNGG
above. This option is enabled by default.
rreessttrriicctteedd__sshheellll
- The shell sets this option if it is started in
+ The shell sets this option if it is started in
restricted mode (see RREESSTTRRIICCTTEEDD SSHHEELLLL below). The value
- may not be changed. This is not reset when the startup
- files are executed, allowing the startup files to dis-
+ may not be changed. This is not reset when the startup
+ files are executed, allowing the startup files to dis-
cover whether or not a shell is restricted.
sshhiifftt__vveerrbboossee
- If set, the sshhiifftt builtin prints an error message when
+ If set, the sshhiifftt builtin prints an error message when
the shift count exceeds the number of positional parame-
ters.
ssoouurrcceeppaatthh
If set, the ssoouurrccee (..) builtin uses the value of PPAATTHH to
- find the directory containing the file supplied as an
+ find the directory containing the file supplied as an
argument. This option is enabled by default.
xxppgg__eecchhoo
- If set, the eecchhoo builtin expands backslash-escape
+ If set, the eecchhoo builtin expands backslash-escape
sequences by default.
ssuussppeenndd [--ff]
- Suspend the execution of this shell until it receives a SSIIGGCCOONNTT
+ Suspend the execution of this shell until it receives a SSIIGGCCOONNTT
signal. A login shell cannot be suspended; the --ff option can be
used to override this and force the suspension. The return sta-
- tus is 0 unless the shell is a login shell and --ff is not sup-
+ tus is 0 unless the shell is a login shell and --ff is not sup-
plied, or if job control is not enabled.
tteesstt _e_x_p_r
[[ _e_x_p_r ]]
Return a status of 0 (true) or 1 (false) depending on the evalu-
ation of the conditional expression _e_x_p_r. Each operator and op-
- erand must be a separate argument. Expressions are composed of
- the primaries described above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS.
- tteesstt does not accept any options, nor does it accept and ignore
+ erand must be a separate argument. Expressions are composed of
+ the primaries described above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS.
+ tteesstt does not accept any options, nor does it accept and ignore
an argument of ---- as signifying the end of options.
- Expressions may be combined using the following operators,
+ Expressions may be combined using the following operators,
listed in decreasing order of precedence. The evaluation
- depends on the number of arguments; see below. Operator prece-
+ depends on the number of arguments; see below. Operator prece-
dence is used when there are five or more arguments.
!! _e_x_p_r True if _e_x_p_r is false.
(( _e_x_p_r ))
- Returns the value of _e_x_p_r. This may be used to override
+ Returns the value of _e_x_p_r. This may be used to override
the normal precedence of operators.
_e_x_p_r_1 -aa _e_x_p_r_2
True if both _e_x_p_r_1 and _e_x_p_r_2 are true.
@@ -5186,63 +5226,63 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
null.
2 arguments
If the first argument is !!, the expression is true if and
- only if the second argument is null. If the first argu-
- ment is one of the unary conditional operators listed
- above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the expression is
+ only if the second argument is null. If the first argu-
+ ment is one of the unary conditional operators listed
+ above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the expression is
true if the unary test is true. If the first argument is
not a valid unary conditional operator, the expression is
false.
3 arguments
The following conditions are applied in the order listed.
- If the second argument is one of the binary conditional
+ If the second argument is one of the binary conditional
operators listed above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the
result of the expression is the result of the binary test
- using the first and third arguments as operands. The --aa
- and --oo operators are considered binary operators when
- there are three arguments. If the first argument is !!,
- the value is the negation of the two-argument test using
+ using the first and third arguments as operands. The --aa
+ and --oo operators are considered binary operators when
+ there are three arguments. If the first argument is !!,
+ the value is the negation of the two-argument test using
the second and third arguments. If the first argument is
exactly (( and the third argument is exactly )), the result
- is the one-argument test of the second argument. Other-
+ is the one-argument test of the second argument. Other-
wise, the expression is false.
4 arguments
If the first argument is !!, the result is the negation of
- the three-argument expression composed of the remaining
+ the three-argument expression composed of the remaining
arguments. Otherwise, the expression is parsed and eval-
- uated according to precedence using the rules listed
+ uated according to precedence using the rules listed
above.
5 or more arguments
- The expression is parsed and evaluated according to
+ The expression is parsed and evaluated according to
precedence using the rules listed above.
- When used with tteesstt or [[, the << and >> operators sort lexico-
+ When used with tteesstt or [[, the << and >> operators sort lexico-
graphically using ASCII ordering.
- ttiimmeess Print the accumulated user and system times for the shell and
+ ttiimmeess Print the accumulated user and system times for the shell and
for processes run from the shell. The return status is 0.
ttrraapp [--llpp] [[_a_r_g] _s_i_g_s_p_e_c ...]
- The command _a_r_g is to be read and executed when the shell
- receives signal(s) _s_i_g_s_p_e_c. If _a_r_g is absent (and there is a
- single _s_i_g_s_p_e_c) or --, each specified signal is reset to its
- original disposition (the value it had upon entrance to the
- shell). If _a_r_g is the null string the signal specified by each
- _s_i_g_s_p_e_c is ignored by the shell and by the commands it invokes.
- If _a_r_g is not present and --pp has been supplied, then the trap
- commands associated with each _s_i_g_s_p_e_c are displayed. If no
- arguments are supplied or if only --pp is given, ttrraapp prints the
- list of commands associated with each signal. The --ll option
- causes the shell to print a list of signal names and their cor-
- responding numbers. Each _s_i_g_s_p_e_c is either a signal name
- defined in <_s_i_g_n_a_l_._h>, or a signal number. Signal names are
+ The command _a_r_g is to be read and executed when the shell
+ receives signal(s) _s_i_g_s_p_e_c. If _a_r_g is absent (and there is a
+ single _s_i_g_s_p_e_c) or --, each specified signal is reset to its
+ original disposition (the value it had upon entrance to the
+ shell). If _a_r_g is the null string the signal specified by each
+ _s_i_g_s_p_e_c is ignored by the shell and by the commands it invokes.
+ If _a_r_g is not present and --pp has been supplied, then the trap
+ commands associated with each _s_i_g_s_p_e_c are displayed. If no
+ arguments are supplied or if only --pp is given, ttrraapp prints the
+ list of commands associated with each signal. The --ll option
+ causes the shell to print a list of signal names and their cor-
+ responding numbers. Each _s_i_g_s_p_e_c is either a signal name
+ defined in <_s_i_g_n_a_l_._h>, or a signal number. Signal names are
case insensitive and the SSIIGG prefix is optional.
- If a _s_i_g_s_p_e_c is EEXXIITT (0) the command _a_r_g is executed on exit
- from the shell. If a _s_i_g_s_p_e_c is DDEEBBUUGG, the command _a_r_g is exe-
- cuted before every _s_i_m_p_l_e _c_o_m_m_a_n_d, _f_o_r command, _c_a_s_e command,
- _s_e_l_e_c_t command, every arithmetic _f_o_r command, and before the
- first command executes in a shell function (see SSHHEELLLL GGRRAAMMMMAARR
- above). Refer to the description of the eexxttddeebbuugg option to the
+ If a _s_i_g_s_p_e_c is EEXXIITT (0) the command _a_r_g is executed on exit
+ from the shell. If a _s_i_g_s_p_e_c is DDEEBBUUGG, the command _a_r_g is exe-
+ cuted before every _s_i_m_p_l_e _c_o_m_m_a_n_d, _f_o_r command, _c_a_s_e command,
+ _s_e_l_e_c_t command, every arithmetic _f_o_r command, and before the
+ first command executes in a shell function (see SSHHEELLLL GGRRAAMMMMAARR
+ above). Refer to the description of the eexxttddeebbuugg option to the
sshhoopptt builtin for details of its effect on the DDEEBBUUGG trap. If a
_s_i_g_s_p_e_c is RREETTUURRNN, the command _a_r_g is executed each time a shell
function or a script executed with the .. or ssoouurrccee builtins fin-
@@ -5250,53 +5290,53 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
If a _s_i_g_s_p_e_c is EERRRR, the command _a_r_g is executed whenever a sim-
ple command has a non-zero exit status, subject to the following
- conditions. The EERRRR trap is not executed if the failed command
- is part of the command list immediately following a wwhhiillee or
- uunnttiill keyword, part of the test in an _i_f statement, part of a
- command executed in a &&&& or |||| list, or if the command's return
- value is being inverted via !!. These are the same conditions
+ conditions. The EERRRR trap is not executed if the failed command
+ is part of the command list immediately following a wwhhiillee or
+ uunnttiill keyword, part of the test in an _i_f statement, part of a
+ command executed in a &&&& or |||| list, or if the command's return
+ value is being inverted via !!. These are the same conditions
obeyed by the eerrrreexxiitt option.
- Signals ignored upon entry to the shell cannot be trapped or
- reset. Trapped signals that are not being ignored are reset to
+ 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 subshell or subshell environment when
- one is created. The return status is false if any _s_i_g_s_p_e_c is
+ one is created. The return status is false if any _s_i_g_s_p_e_c is
invalid; otherwise ttrraapp returns true.
ttyyppee [--aaffttppPP] _n_a_m_e [_n_a_m_e ...]
- With no options, indicate how each _n_a_m_e would be interpreted if
+ With no options, indicate how each _n_a_m_e would be interpreted if
used as a command name. If the --tt option is used, ttyyppee prints a
- string which is one of _a_l_i_a_s, _k_e_y_w_o_r_d, _f_u_n_c_t_i_o_n, _b_u_i_l_t_i_n, or
- _f_i_l_e if _n_a_m_e is an alias, shell reserved word, function,
- builtin, or disk file, respectively. If the _n_a_m_e is not found,
- then nothing is printed, and an exit status of false is
- returned. If the --pp option is used, ttyyppee either returns the
+ string which is one of _a_l_i_a_s, _k_e_y_w_o_r_d, _f_u_n_c_t_i_o_n, _b_u_i_l_t_i_n, or
+ _f_i_l_e if _n_a_m_e is an alias, shell reserved word, function,
+ builtin, or disk file, respectively. If the _n_a_m_e is not found,
+ then nothing is printed, and an exit status of false is
+ returned. If the --pp option is used, ttyyppee either returns the
name of the disk file that would be executed if _n_a_m_e were speci-
fied as a command name, or nothing if ``type -t name'' would not
- return _f_i_l_e. The --PP option forces a PPAATTHH search for each _n_a_m_e,
+ return _f_i_l_e. The --PP option forces a PPAATTHH search for each _n_a_m_e,
even if ``type -t name'' would not return _f_i_l_e. If a command is
hashed, --pp and --PP print the hashed value, which is not necessar-
- ily the file that appears first in PPAATTHH. If the --aa option is
- used, ttyyppee prints all of the places that contain an executable
+ ily the file that appears first in PPAATTHH. If the --aa option is
+ used, ttyyppee prints all of the places that contain an executable
named _n_a_m_e. This includes aliases and functions, if and only if
the --pp option is not also used. The table of hashed commands is
- not consulted when using --aa. The --ff option suppresses shell
+ not consulted when using --aa. The --ff option suppresses shell
function lookup, as with the ccoommmmaanndd builtin. ttyyppee returns true
if all of the arguments are found, false if any are not found.
uulliimmiitt [--HHSSTTaabbccddeeffiillmmnnppqqrrssttuuvvxx [_l_i_m_i_t]]
- Provides control over the resources available to the shell and
- to processes started by it, on systems that allow such control.
+ Provides control over the resources available to the shell and
+ to processes started by it, on systems that allow such control.
The --HH and --SS options specify that the hard or soft limit is set
- for the given resource. A hard limit cannot be increased by a
- non-root user once it is set; a soft limit may be increased up
- to the value of the hard limit. If neither --HH nor --SS is speci-
+ for the given resource. A hard limit cannot be increased by a
+ non-root user once it is set; a soft limit may be increased up
+ to the value of the hard limit. If neither --HH nor --SS is speci-
fied, both the soft and hard limits are set. The value of _l_i_m_i_t
can be a number in the unit specified for the resource or one of
the special values hhaarrdd, ssoofftt, or uunnlliimmiitteedd, which stand for the
- current hard limit, the current soft limit, and no limit,
- respectively. If _l_i_m_i_t is omitted, the current value of the
- soft limit of the resource is printed, unless the --HH option is
+ current hard limit, the current soft limit, and no limit,
+ respectively. If _l_i_m_i_t is omitted, the current value of the
+ soft limit of the resource is printed, unless the --HH option is
given. When more than one resource is specified, the limit name
and unit are printed before the value. Other options are inter-
preted as follows:
@@ -5305,11 +5345,11 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
--cc The maximum size of core files created
--dd The maximum size of a process's data segment
--ee The maximum scheduling priority ("nice")
- --ff The maximum size of files written by the shell and its
+ --ff The maximum size of files written by the shell and its
children
--ii The maximum number of pending signals
--ll The maximum size that may be locked into memory
- --mm The maximum resident set size (many systems do not honor
+ --mm The maximum resident set size (many systems do not honor
this limit)
--nn The maximum number of open file descriptors (most systems
do not allow this value to be set)
@@ -5318,68 +5358,68 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
--rr The maximum real-time scheduling priority
--ss The maximum stack size
--tt The maximum amount of cpu time in seconds
- --uu The maximum number of processes available to a single
+ --uu The maximum number of processes available to a single
user
- --vv The maximum amount of virtual memory available to the
+ --vv The maximum amount of virtual memory available to the
shell and, on some systems, to its children
--xx The maximum number of file locks
--TT The maximum number of threads
- If _l_i_m_i_t is given, and the --aa option is not used, _l_i_m_i_t is the
- new value of the specified resource. If no option is given,
- then --ff is assumed. Values are in 1024-byte increments, except
- for --tt, which is in seconds; --pp, which is in units of 512-byte
- blocks; and --TT, --bb, --nn, and --uu, which are unscaled values. The
- return status is 0 unless an invalid option or argument is sup-
+ If _l_i_m_i_t is given, and the --aa option is not used, _l_i_m_i_t is the
+ new value of the specified resource. If no option is given,
+ then --ff is assumed. Values are in 1024-byte increments, except
+ for --tt, which is in seconds; --pp, which is in units of 512-byte
+ blocks; and --TT, --bb, --nn, and --uu, which are unscaled values. The
+ return status is 0 unless an invalid option or argument is sup-
plied, or an error occurs while setting a new limit.
uummaasskk [--pp] [--SS] [_m_o_d_e]
The user file-creation mask is set to _m_o_d_e. If _m_o_d_e begins with
- a digit, it is interpreted as an octal number; otherwise it is
- interpreted as a symbolic mode mask similar to that accepted by
- _c_h_m_o_d(1). If _m_o_d_e is omitted, the current value of the mask is
- printed. The --SS option causes the mask to be printed in sym-
- bolic form; the default output is an octal number. If the --pp
+ a digit, it is interpreted as an octal number; otherwise it is
+ interpreted as a symbolic mode mask similar to that accepted by
+ _c_h_m_o_d(1). If _m_o_d_e is omitted, the current value of the mask is
+ printed. The --SS option causes the mask to be printed in sym-
+ bolic form; the default output is an octal number. If the --pp
option is supplied, and _m_o_d_e is omitted, the output is in a form
that may be reused as input. The return status is 0 if the mode
- was successfully changed or if no _m_o_d_e argument was supplied,
+ was successfully changed or if no _m_o_d_e argument was supplied,
and false otherwise.
uunnaalliiaass [-aa] [_n_a_m_e ...]
- Remove each _n_a_m_e from the list of defined aliases. If --aa is
- supplied, all alias definitions are removed. The return value
+ Remove each _n_a_m_e from the list of defined aliases. If --aa is
+ supplied, all alias definitions are removed. The return value
is true unless a supplied _n_a_m_e is not a defined alias.
uunnsseett [-ffvv] [_n_a_m_e ...]
- For each _n_a_m_e, remove the corresponding variable or function.
+ For each _n_a_m_e, remove the corresponding variable or function.
If the --vv option is given, each _n_a_m_e refers to a shell variable,
- and that variable is removed. Read-only variables may not be
- unset. If --ff is specified, each _n_a_m_e refers to a shell func-
+ and that variable is removed. Read-only variables may not be
+ unset. If --ff is specified, each _n_a_m_e refers to a shell func-
tion, and the function definition is removed. If no options are
- supplied, each _n_a_m_e refers to a variable; if there is no vari-
- able by that name, any function with that name is unset. Each
- unset variable or function is removed from the environment
- passed to subsequent commands. If any of CCOOMMPP__WWOORRDDBBRREEAAKKSS, RRAANN--
+ supplied, each _n_a_m_e refers to a variable; if there is no vari-
+ able by that name, any function with that name is unset. Each
+ unset variable or function is removed from the environment
+ passed to subsequent commands. If any of CCOOMMPP__WWOORRDDBBRREEAAKKSS, RRAANN--
DDOOMM, SSEECCOONNDDSS, LLIINNEENNOO, HHIISSTTCCMMDD, FFUUNNCCNNAAMMEE, GGRROOUUPPSS, or DDIIRRSSTTAACCKK are
unset, they lose their special properties, even if they are sub-
sequently reset. The exit status is true unless a _n_a_m_e is read-
only.
wwaaiitt [_n _._._.]
- Wait for each specified process and return its termination sta-
- tus. Each _n may be a process ID or a job specification; if a
- job spec is given, all processes in that job's pipeline are
- waited for. If _n is not given, all currently active child pro-
- cesses are waited for, and the return status is zero. If _n
- specifies a non-existent process or job, the return status is
- 127. Otherwise, the return status is the exit status of the
+ Wait for each specified process and return its termination sta-
+ tus. Each _n may be a process ID or a job specification; if a
+ job spec is given, all processes in that job's pipeline are
+ waited for. If _n is not given, all currently active child pro-
+ cesses are waited for, and the return status is zero. If _n
+ specifies a non-existent process or job, the return status is
+ 127. Otherwise, the return status is the exit status of the
last process or job waited for.
RREESSTTRRIICCTTEEDD SSHHEELLLL
If bbaasshh is started with the name rrbbaasshh, or the --rr 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. It
- behaves identically to bbaasshh with the exception that the following are
+ invocation, the shell becomes restricted. A restricted shell is used
+ to set up an environment more controlled than the standard shell. It
+ behaves identically to bbaasshh with the exception that the following are
disallowed or not performed:
+o changing directories with ccdd
@@ -5388,16 +5428,16 @@ RREESSTTRRIICCTTEEDD SSHHEELLLL
+o specifying command names containing //
- +o specifying a filename containing a // as an argument to the ..
+ +o specifying a filename containing a // as an argument to the ..
builtin command
- +o specifying a filename containing a slash as an argument to the
+ +o specifying a filename containing a slash as an argument to the
--pp option to the hhaasshh builtin command
- +o importing function definitions from the shell environment at
+ +o importing function definitions from the shell environment at
startup
- +o parsing the value of SSHHEELLLLOOPPTTSS from the shell environment at
+ +o parsing the value of SSHHEELLLLOOPPTTSS from the shell environment at
startup
+o redirecting output using the >, >|, <>, >&, &>, and >> redirect-
@@ -5406,10 +5446,10 @@ RREESSTTRRIICCTTEEDD SSHHEELLLL
+o using the eexxeecc builtin command to replace the shell with another
command
- +o adding or deleting builtin commands with the --ff and --dd options
+ +o adding or deleting builtin commands with the --ff and --dd options
to the eennaabbllee builtin command
- +o using the eennaabbllee builtin command to enable disabled shell
+ +o using the eennaabbllee builtin command to enable disabled shell
builtins
+o specifying the --pp option to the ccoommmmaanndd builtin command
@@ -5419,14 +5459,14 @@ RREESSTTRRIICCTTEEDD SSHHEELLLL
These restrictions are enforced after any startup files are read.
When a command that is found to be a shell script is executed (see CCOOMM--
- MMAANNDD EEXXEECCUUTTIIOONN above), rrbbaasshh turns off any restrictions in the shell
+ MMAANNDD EEXXEECCUUTTIIOONN above), rrbbaasshh turns off any restrictions in the shell
spawned to execute the script.
SSEEEE AALLSSOO
_B_a_s_h _R_e_f_e_r_e_n_c_e _M_a_n_u_a_l, Brian Fox and Chet Ramey
_T_h_e _G_n_u _R_e_a_d_l_i_n_e _L_i_b_r_a_r_y, Brian Fox and Chet Ramey
_T_h_e _G_n_u _H_i_s_t_o_r_y _L_i_b_r_a_r_y, Brian Fox and Chet Ramey
- _P_o_r_t_a_b_l_e _O_p_e_r_a_t_i_n_g _S_y_s_t_e_m _I_n_t_e_r_f_a_c_e _(_P_O_S_I_X_) _P_a_r_t _2_: _S_h_e_l_l _a_n_d _U_t_i_l_i_-
+ _P_o_r_t_a_b_l_e _O_p_e_r_a_t_i_n_g _S_y_s_t_e_m _I_n_t_e_r_f_a_c_e _(_P_O_S_I_X_) _P_a_r_t _2_: _S_h_e_l_l _a_n_d _U_t_i_l_i_-
_t_i_e_s, IEEE
_s_h(1), _k_s_h(1), _c_s_h(1)
_e_m_a_c_s(1), _v_i(1)
@@ -5442,7 +5482,7 @@ FFIILLEESS
_~_/_._b_a_s_h_r_c
The individual per-interactive-shell startup file
_~_/_._b_a_s_h___l_o_g_o_u_t
- The individual login shell cleanup file, executed when a login
+ The individual login shell cleanup file, executed when a login
shell exits
_~_/_._i_n_p_u_t_r_c
Individual _r_e_a_d_l_i_n_e initialization file
@@ -5456,14 +5496,14 @@ AAUUTTHHOORRSS
BBUUGG RREEPPOORRTTSS
If you find a bug in bbaasshh,, you should report it. But first, you should
- make sure that it really is a bug, and that it appears in the latest
- version of bbaasshh. The latest version is always available from
+ make sure that it really is a bug, and that it appears in the latest
+ version of bbaasshh. The latest version is always available from
_f_t_p_:_/_/_f_t_p_._g_n_u_._o_r_g_/_p_u_b_/_g_n_u_/_b_a_s_h_/.
- Once you have determined that a bug actually exists, use the _b_a_s_h_b_u_g
- 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 _b_u_g_-_b_a_s_h_@_g_n_u_._o_r_g or posted to the Usenet newsgroup
+ Once you have determined that a bug actually exists, use the _b_a_s_h_b_u_g
+ 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 _b_u_g_-_b_a_s_h_@_g_n_u_._o_r_g or posted to the Usenet newsgroup
ggnnuu..bbaasshh..bbuugg.
ALL bug reports should include:
@@ -5474,7 +5514,7 @@ BBUUGG RREEPPOORRTTSS
A description of the bug behaviour
A short script or `recipe' which exercises the bug
- _b_a_s_h_b_u_g inserts the first three items automatically into the template
+ _b_a_s_h_b_u_g inserts the first three items automatically into the template
it provides for filing a bug report.
Comments and bug reports concerning this manual page should be directed
@@ -5491,10 +5531,10 @@ BBUUGGSS
Shell builtin commands and functions are not stoppable/restartable.
Compound commands and command sequences of the form `a ; b ; c' are not
- handled gracefully when process suspension is attempted. When a
- process is stopped, the shell immediately executes the next command in
- the sequence. It suffices to place the sequence of commands between
- parentheses to force it into a subshell, which may be stopped as a
+ handled gracefully when process suspension is attempted. When a
+ process is stopped, the shell immediately executes the next command in
+ the sequence. It suffices to place the sequence of commands between
+ parentheses to force it into a subshell, which may be stopped as a
unit.
Array variables may not (yet) be exported.
@@ -5503,4 +5543,4 @@ BBUUGGSS
-GNU Bash 4.2 2011 September 25 BASH(1)
+GNU Bash 4.2 2011 December 24 BASH(1)