D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
B\bBa\bas\bsh\bh is an s\bsh\bh-compatible command language interpreter that executes
- commands read from the standard input or from a file. B\bBa\bas\bsh\bh also incor-
+ commands read from the standard input or from a file. B\bBa\bas\bsh\bh also incor-
porates useful features from the _\bK_\bo_\br_\bn and _\bC shells (k\bks\bsh\bh and c\bcs\bsh\bh).
B\bBa\bas\bsh\bh is intended to be a conformant implementation of the Shell and
Utilities portion of the IEEE POSIX specification (IEEE Standard
- 1003.1). B\bBa\bas\bsh\bh can be configured to be POSIX-conformant by default.
+ 1003.1). B\bBa\bas\bsh\bh can be configured to be POSIX-conformant by default.
O\bOP\bPT\bTI\bIO\bON\bNS\bS
All of the single-character shell options documented in the description
of the s\bse\bet\bt builtin command, including -\b-o\bo, can be used as options when
- the shell is invoked. In addition, b\bba\bas\bsh\bh interprets the following op-
+ the shell is invoked. In addition, b\bba\bas\bsh\bh interprets the following op-
tions when it is invoked:
-\b-c\bc If the -\b-c\bc option is present, then commands are read from the
- first non-option argument _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b__\bs_\bt_\br_\bi_\bn_\bg. If there are argu-
+ first non-option argument _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b__\bs_\bt_\br_\bi_\bn_\bg. If there are argu-
ments after the _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b__\bs_\bt_\br_\bi_\bn_\bg, the first argument is as-
signed to $\b$0\b0 and any remaining arguments are assigned to the
- positional parameters. The assignment to $\b$0\b0 sets the name of
+ positional parameters. The assignment to $\b$0\b0 sets the name of
the shell, which is used in warning and error messages.
-\b-i\bi If the -\b-i\bi option is present, the shell is _\bi_\bn_\bt_\be_\br_\ba_\bc_\bt_\bi_\bv_\be.
-\b-l\bl Make b\bba\bas\bsh\bh act as if it had been invoked as a login shell (see
(see R\bRE\bES\bST\bTR\bRI\bIC\bCT\bTE\bED\bD S\bSH\bHE\bEL\bLL\bL below).
-\b-s\bs If the -\b-s\bs 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 or when reading input
+ input. This option allows the positional parameters to be
+ set when invoking an interactive shell or when reading input
through a pipe.
-\b-D\bD A list of all double-quoted strings preceded by $\b$ is printed
- on the standard output. These are the strings that are sub-
+ on the standard output. These are the strings that are sub-
ject to language translation when the current locale is not C\bC
- or P\bPO\bOS\bSI\bIX\bX. This implies the -\b-n\bn option; no commands will be ex-
- ecuted.
+ or P\bPO\bOS\bSI\bIX\bX. This implies the -\b-n\bn option; no commands will be
+ executed.
[\b[-\b-+\b+]\b]O\bO [\b[_\bs_\bh_\bo_\bp_\bt_\b__\bo_\bp_\bt_\bi_\bo_\bn]\b]
_\bs_\bh_\bo_\bp_\bt_\b__\bo_\bp_\bt_\bi_\bo_\bn is one of the shell options accepted by the
- s\bsh\bho\bop\bpt\bt builtin (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). If
+ s\bsh\bho\bop\bpt\bt builtin (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). If
_\bs_\bh_\bo_\bp_\bt_\b__\bo_\bp_\bt_\bi_\bo_\bn is present, -\b-O\bO sets the value of that option; +\b+O\bO
- unsets it. If _\bs_\bh_\bo_\bp_\bt_\b__\bo_\bp_\bt_\bi_\bo_\bn is not supplied, the names and
+ unsets it. If _\bs_\bh_\bo_\bp_\bt_\b__\bo_\bp_\bt_\bi_\bo_\bn is not supplied, the names and
values of the shell options accepted by s\bsh\bho\bop\bpt\bt are printed on
- the standard output. If the invocation option is +\b+O\bO, the out-
- put is displayed in a format that may be reused as input.
+ the standard output. If the invocation option is +\b+O\bO, the
+ output is displayed in a format that may be reused as input.
-\b--\b- A -\b--\b- signals the end of options and disables further option
- processing. Any arguments after the -\b--\b- are treated as file-
- names and arguments. An argument of -\b- is equivalent to -\b--\b-.
+ processing. Any arguments after the -\b--\b- are treated as file-
+ names and arguments. An argument of -\b- is equivalent to -\b--\b-.
- B\bBa\bas\bsh\bh also interprets a number of multi-character options. These options
- must appear on the command line before the single-character options to
- be recognized.
+ B\bBa\bas\bsh\bh also interprets a number of multi-character options. These op-
+ tions must appear on the command line before the single-character op-
+ tions to be recognized.
-\b--\b-d\bde\beb\bbu\bug\bgg\bge\ber\br
Arrange for the debugger profile to be executed before the shell
- starts. Turns on extended debugging mode (see the description of
- the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the s\bsh\bho\bop\bpt\bt builtin below).
+ starts. Turns on extended debugging mode (see the description
+ of the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the s\bsh\bho\bop\bpt\bt builtin below).
-\b--\b-d\bdu\bum\bmp\bp-\b-p\bpo\bo-\b-s\bst\btr\bri\bin\bng\bgs\bs
Equivalent to -\b-D\bD, but the output is in the GNU _\bg_\be_\bt_\bt_\be_\bx_\bt p\bpo\bo (por-
table object) file format.
-\b--\b-n\bno\bop\bpr\bro\bof\bfi\bil\ble\be
Do not read either the system-wide startup file _\b/_\be_\bt_\bc_\b/_\bp_\br_\bo_\bf_\bi_\bl_\be or
any of the personal initialization files _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bp_\br_\bo_\bf_\bi_\bl_\be,
- _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bl_\bo_\bg_\bi_\bn, or _\b~_\b/_\b._\bp_\br_\bo_\bf_\bi_\bl_\be. By default, b\bba\bas\bsh\bh reads these files
- when it is invoked as a login shell (see I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN below).
+ _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bl_\bo_\bg_\bi_\bn, or _\b~_\b/_\b._\bp_\br_\bo_\bf_\bi_\bl_\be. By default, b\bba\bas\bsh\bh reads these
+ files when it is invoked as a login shell (see I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN be-
+ low).
-\b--\b-n\bno\bor\brc\bc Do not read and execute the personal initialization file
- _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc if the shell is interactive. This option is on by de-
+ _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc if the shell is interactive. This option is on by de-
fault if the shell is invoked as s\bsh\bh.
-\b--\b-p\bpo\bos\bsi\bix\bx
- Change the behavior of b\bba\bas\bsh\bh where the default operation differs
+ Change the behavior of b\bba\bas\bsh\bh where the default operation differs
from the POSIX standard to match the standard (_\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be). See
- S\bSE\bEE\bE A\bAL\bLS\bSO\bO below for a reference to a document that details how
+ S\bSE\bEE\bE A\bAL\bLS\bSO\bO below for a reference to a document that details how
posix mode affects bash's behavior.
-\b--\b-r\bre\bes\bst\btr\bri\bic\bct\bte\bed\bd
Equivalent to -\b-v\bv.
-\b--\b-v\bve\ber\brs\bsi\bio\bon\bn
- Show version information for this instance of b\bba\bas\bsh\bh on the stan-
+ Show version information for this instance of b\bba\bas\bsh\bh on the stan-
dard output and exit successfully.
A\bAR\bRG\bGU\bUM\bME\bEN\bNT\bTS\bS
If arguments remain after option processing, and neither the -\b-c\bc nor the
- -\b-s\bs option has been supplied, the first argument is assumed to be the
- name of a file containing shell commands. If b\bba\bas\bsh\bh is invoked in this
- fashion, $\b$0\b0 is set to the name of the file, and the positional parame-
- ters are set to the remaining arguments. B\bBa\bas\bsh\bh reads and executes com-
- mands from this file, then exits. B\bBa\bas\bsh\bh's exit status is the exit status
- of the last command executed in the script. If no commands are exe-
- cuted, 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
+ -\b-s\bs option has been supplied, the first argument is assumed to be the
+ name of a file containing shell commands. If b\bba\bas\bsh\bh is invoked in this
+ fashion, $\b$0\b0 is set to the name of the file, and the positional parame-
+ ters are set to the remaining arguments. B\bBa\bas\bsh\bh reads and executes com-
+ mands from this file, then exits. B\bBa\bas\bsh\bh's exit status is the exit sta-
+ tus of the last command executed in the script. If no commands are ex-
+ ecuted, 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 P\bPA\bAT\bTH\bH for the script.
I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN
- A _\bl_\bo_\bg_\bi_\bn _\bs_\bh_\be_\bl_\bl is one whose first character of argument zero is a -\b-, or
+ A _\bl_\bo_\bg_\bi_\bn _\bs_\bh_\be_\bl_\bl is one whose first character of argument zero is a -\b-, or
one started with the -\b--\b-l\blo\bog\bgi\bin\bn option.
- An _\bi_\bn_\bt_\be_\br_\ba_\bc_\bt_\bi_\bv_\be shell is one started without non-option arguments (un-
- less -\b-s\bs is specified) and without the -\b-c\bc option, whose standard input
+ An _\bi_\bn_\bt_\be_\br_\ba_\bc_\bt_\bi_\bv_\be shell is one started without non-option arguments (un-
+ less -\b-s\bs is specified) and without the -\b-c\bc option, whose standard input
and error are both connected to terminals (as determined by _\bi_\bs_\ba_\bt_\bt_\by(3)),
- or one started with the -\b-i\bi option. P\bPS\bS1\b1 is set and $\b$-\b- includes i\bi if b\bba\bas\bsh\bh
- is interactive, allowing a shell script or a startup file to test this
- state.
+ or one started with the -\b-i\bi option. P\bPS\bS1\b1 is set and $\b$-\b- includes i\bi if
+ b\bba\bas\bsh\bh is interactive, allowing a shell script or a startup file to test
+ this state.
- The following paragraphs describe how b\bba\bas\bsh\bh executes its startup files.
- If any of the files exist but cannot be read, b\bba\bas\bsh\bh reports an error.
- Tildes are expanded in filenames as described below under T\bTi\bil\bld\bde\be E\bEx\bxp\bpa\ban\bn-\b-
+ The following paragraphs describe how b\bba\bas\bsh\bh executes its startup files.
+ If any of the files exist but cannot be read, b\bba\bas\bsh\bh reports an error.
+ Tildes are expanded in filenames as described below under T\bTi\bil\bld\bde\be E\bEx\bxp\bpa\ban\bn-\b-
s\bsi\bio\bon\bn in the E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN section.
- When b\bba\bas\bsh\bh is invoked as an interactive login shell, or as a non-inter-
- active shell with the -\b--\b-l\blo\bog\bgi\bin\bn option, it first reads and executes com-
- mands from the file _\b/_\be_\bt_\bc_\b/_\bp_\br_\bo_\bf_\bi_\bl_\be, if that file exists. After reading
+ When b\bba\bas\bsh\bh is invoked as an interactive login shell, or as a non-inter-
+ active shell with the -\b--\b-l\blo\bog\bgi\bin\bn option, it first reads and executes com-
+ mands from the file _\b/_\be_\bt_\bc_\b/_\bp_\br_\bo_\bf_\bi_\bl_\be, if that file exists. After reading
that file, it looks for _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bp_\br_\bo_\bf_\bi_\bl_\be, _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bl_\bo_\bg_\bi_\bn, and _\b~_\b/_\b._\bp_\br_\bo_\bf_\bi_\bl_\be,
- in that order, and reads and executes commands from the first one that
- exists and is readable. The -\b--\b-n\bno\bop\bpr\bro\bof\bfi\bil\ble\be option may be used when the
+ in that order, and reads and executes commands from the first one that
+ exists and is readable. The -\b--\b-n\bno\bop\bpr\bro\bof\bfi\bil\ble\be option may be used when the
shell is started to inhibit this behavior.
When an interactive login shell exits, or a non-interactive login shell
- executes the e\bex\bxi\bit\bt builtin command, b\bba\bas\bsh\bh reads and executes commands
+ executes the e\bex\bxi\bit\bt builtin command, b\bba\bas\bsh\bh reads and executes commands
from the file _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bl_\bo_\bg_\bo_\bu_\bt, if it exists.
- When an interactive shell that is not a login shell is started, b\bba\bas\bsh\bh
- reads and executes commands from _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc, if that file exists. This
- may be inhibited by using the -\b--\b-n\bno\bor\brc\bc option. The -\b--\b-r\brc\bcf\bfi\bil\ble\be _\bf_\bi_\bl_\be option
- will force b\bba\bas\bsh\bh to read and execute commands from _\bf_\bi_\bl_\be instead of
+ When an interactive shell that is not a login shell is started, b\bba\bas\bsh\bh
+ reads and executes commands from _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc, if that file exists. This
+ may be inhibited by using the -\b--\b-n\bno\bor\brc\bc option. The -\b--\b-r\brc\bcf\bfi\bil\ble\be _\bf_\bi_\bl_\be option
+ will force b\bba\bas\bsh\bh to read and execute commands from _\bf_\bi_\bl_\be instead of
_\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc.
- When b\bba\bas\bsh\bh is started non-interactively, to run a shell script, for ex-
- ample, it looks for the variable B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV 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. B\bBa\bas\bsh\bh behaves as if the following command
- were executed:
+ When b\bba\bas\bsh\bh is started non-interactively, to run a shell script, for ex-
+ ample, it looks for the variable B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV 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. B\bBa\bas\bsh\bh behaves as if the following com-
+ mand were executed:
if [ -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi
- but the value of the P\bPA\bAT\bTH\bH variable is not used to search for the file-
+ but the value of the P\bPA\bAT\bTH\bH variable is not used to search for the file-
name.
- If b\bba\bas\bsh\bh is invoked with the name s\bsh\bh, it tries to mimic the startup be-
- havior of historical versions of s\bsh\bh as closely as possible, while con-
- forming to the POSIX standard as well. When invoked as an interactive
- login shell, or a non-interactive shell with the -\b--\b-l\blo\bog\bgi\bin\bn option, it
- first attempts to read and execute commands from _\b/_\be_\bt_\bc_\b/_\bp_\br_\bo_\bf_\bi_\bl_\be and
- _\b~_\b/_\b._\bp_\br_\bo_\bf_\bi_\bl_\be, in that order. The -\b--\b-n\bno\bop\bpr\bro\bof\bfi\bil\ble\be option may be used to in-
- hibit this behavior. When invoked as an interactive shell with the name
- s\bsh\bh, b\bba\bas\bsh\bh looks for the variable E\bEN\bNV\bV, expands its value if it is de-
- fined, and uses the expanded value as the name of a file to read and
+ If b\bba\bas\bsh\bh is invoked with the name s\bsh\bh, it tries to mimic the startup be-
+ havior of historical versions of s\bsh\bh as closely as possible, while con-
+ forming to the POSIX standard as well. When invoked as an interactive
+ login shell, or a non-interactive shell with the -\b--\b-l\blo\bog\bgi\bin\bn option, it
+ first attempts to read and execute commands from _\b/_\be_\bt_\bc_\b/_\bp_\br_\bo_\bf_\bi_\bl_\be and
+ _\b~_\b/_\b._\bp_\br_\bo_\bf_\bi_\bl_\be, in that order. The -\b--\b-n\bno\bop\bpr\bro\bof\bfi\bil\ble\be option may be used to in-
+ hibit this behavior. When invoked as an interactive shell with the
+ name s\bsh\bh, b\bba\bas\bsh\bh looks for the variable E\bEN\bNV\bV, 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 s\bsh\bh does not attempt to read and exe-
- cute commands from any other startup files, the -\b--\b-r\brc\bcf\bfi\bil\ble\be option has no
- effect. A non-interactive shell invoked with the name s\bsh\bh does not at-
- tempt to read any other startup files. When invoked as s\bsh\bh, b\bba\bas\bsh\bh enters
+ cute commands from any other startup files, the -\b--\b-r\brc\bcf\bfi\bil\ble\be option has no
+ effect. A non-interactive shell invoked with the name s\bsh\bh does not at-
+ tempt to read any other startup files. When invoked as s\bsh\bh, b\bba\bas\bsh\bh enters
_\bp_\bo_\bs_\bi_\bx mode after the startup files are read.
- When b\bba\bas\bsh\bh is started in _\bp_\bo_\bs_\bi_\bx mode, as with the -\b--\b-p\bpo\bos\bsi\bix\bx command line
- option, it follows the POSIX standard for startup files. In this mode,
- interactive shells expand the E\bEN\bNV\bV variable and commands are read and
- executed from the file whose name is the expanded value. No other
+ When b\bba\bas\bsh\bh is started in _\bp_\bo_\bs_\bi_\bx mode, as with the -\b--\b-p\bpo\bos\bsi\bix\bx command line
+ option, it follows the POSIX standard for startup files. In this mode,
+ interactive shells expand the E\bEN\bNV\bV variable and commands are read and
+ executed from the file whose name is the expanded value. No other
startup files are read.
B\bBa\bas\bsh\bh attempts to determine when it is being run with its standard input
- connected to a network connection, as when executed by the historical
- remote shell daemon, usually _\br_\bs_\bh_\bd, or the secure shell daemon _\bs_\bs_\bh_\bd. If
- b\bba\bas\bsh\bh determines it is being run non-interactively in this fashion, it
- reads and executes commands from _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc, if that file exists and is
- readable. It will not do this if invoked as s\bsh\bh. The -\b--\b-n\bno\bor\brc\bc option may
- be used to inhibit this behavior, and the -\b--\b-r\brc\bcf\bfi\bil\ble\be option may be used
- to force another file to be read, but neither _\br_\bs_\bh_\bd nor _\bs_\bs_\bh_\bd generally
+ connected to a network connection, as when executed by the historical
+ remote shell daemon, usually _\br_\bs_\bh_\bd, or the secure shell daemon _\bs_\bs_\bh_\bd. If
+ b\bba\bas\bsh\bh determines it is being run non-interactively in this fashion, it
+ reads and executes commands from _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc, if that file exists and is
+ readable. It will not do this if invoked as s\bsh\bh. The -\b--\b-n\bno\bor\brc\bc option may
+ be used to inhibit this behavior, and the -\b--\b-r\brc\bcf\bfi\bil\ble\be option may be used
+ to force another file to be read, but neither _\br_\bs_\bh_\bd nor _\bs_\bs_\bh_\bd 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 -\b-p\bp option is not supplied, no startup
files are read, shell functions are not inherited from the environment,
- the S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS, B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS, C\bCD\bDP\bPA\bAT\bTH\bH, and G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE variables, if they ap-
- pear in the environment, are ignored, and the effective user id is set
- to the real user id. If the -\b-p\bp option is supplied at invocation, the
+ the S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS, B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS, C\bCD\bDP\bPA\bAT\bTH\bH, and G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE variables, if they ap-
+ pear in the environment, are ignored, and the effective user id is set
+ to the real user id. If the -\b-p\bp option is supplied at invocation, the
startup behavior is the same, but the effective user id is not reset.
D\bDE\bEF\bFI\bIN\bNI\bIT\bTI\bIO\bON\bNS\bS
- The following definitions are used throughout the rest of this docu-
+ The following definitions are used throughout the rest of this docu-
ment.
b\bbl\bla\ban\bnk\bk A space or tab.
- w\bwo\bor\brd\bd A sequence of characters considered as a single unit by the
- shell. Also known as a t\bto\bok\bke\ben\bn.
- n\bna\bam\bme\be A _\bw_\bo_\br_\bd consisting only of alphanumeric characters and under-
- scores, and beginning with an alphabetic character or an under-
- score. Also referred to as an i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br.
+ w\bwo\bor\brd\bd A sequence of characters considered as a single unit by the
+ shell. Also known as a t\bto\bok\bke\ben\bn.
+ n\bna\bam\bme\be A _\bw_\bo_\br_\bd consisting only of alphanumeric characters and under-
+ scores, and beginning with an alphabetic character or an under-
+ score. Also referred to as an i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br.
m\bme\bet\bta\bac\bch\bha\bar\bra\bac\bct\bte\ber\br
- A character that, when unquoted, separates words. One of the
+ A character that, when unquoted, separates words. One of the
following:
|\b| &\b& ;\b; (\b( )\b) <\b< >\b> s\bsp\bpa\bac\bce\be t\bta\bab\bb n\bne\bew\bwl\bli\bin\bne\be
c\bco\bon\bnt\btr\bro\bol\bl o\bop\bpe\ber\bra\bat\bto\bor\br
- A _\bt_\bo_\bk_\be_\bn that performs a control function. It is one of the fol-
+ A _\bt_\bo_\bk_\be_\bn that performs a control function. It is one of the fol-
lowing symbols:
|\b||\b| &\b& &\b&&\b& ;\b; ;\b;;\b; ;\b;&\b& ;\b;;\b;&\b& (\b( )\b) |\b| |\b|&\b& <\b<n\bne\bew\bwl\bli\bin\bne\be>\b>
R\bRE\bES\bSE\bER\bRV\bVE\bED\bD W\bWO\bOR\bRD\bDS\bS
- _\bR_\be_\bs_\be_\br_\bv_\be_\bd _\bw_\bo_\br_\bd_\bs are words that have a special meaning to the shell. The
+ _\bR_\be_\bs_\be_\br_\bv_\be_\bd _\bw_\bo_\br_\bd_\bs 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 command (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR below), the third word of a
- c\bca\bas\bse\be or s\bse\bel\ble\bec\bct\bt command (only i\bin\bn is valid), or the third word of a f\bfo\bor\br
+ first word of a command (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR below), the third word of a
+ c\bca\bas\bse\be or s\bse\bel\ble\bec\bct\bt command (only i\bin\bn is valid), or the third word of a f\bfo\bor\br
command (only i\bin\bn and d\bdo\bo are valid):
- !\b! c\bca\bas\bse\be c\bco\bop\bpr\bro\boc\bc d\bdo\bo d\bdo\bon\bne\be e\bel\bli\bif\bf e\bel\bls\bse\be e\bes\bsa\bac\bc f\bfi\bi f\bfo\bor\br f\bfu\bun\bnc\bct\bti\bio\bon\bn i\bif\bf i\bin\bn s\bse\bel\ble\bec\bct\bt
+ !\b! c\bca\bas\bse\be c\bco\bop\bpr\bro\boc\bc d\bdo\bo d\bdo\bon\bne\be e\bel\bli\bif\bf e\bel\bls\bse\be e\bes\bsa\bac\bc f\bfi\bi f\bfo\bor\br f\bfu\bun\bnc\bct\bti\bio\bon\bn i\bif\bf i\bin\bn s\bse\bel\ble\bec\bct\bt
t\bth\bhe\ben\bn u\bun\bnt\bti\bil\bl w\bwh\bhi\bil\ble\be {\b{ }\b} t\bti\bim\bme\be [\b[[\b[ ]\b]]\b]
S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR
- This section describes the syntax of the various forms of shell com-
+ This section describes the syntax of the various forms of shell com-
mands.
S\bSi\bim\bmp\bpl\ble\be C\bCo\bom\bmm\bma\ban\bnd\bds\bs
- A _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a sequence of optional variable assignments fol-
- lowed by b\bbl\bla\ban\bnk\bk-separated words and redirections, and terminated by a
- _\bc_\bo_\bn_\bt_\br_\bo_\bl _\bo_\bp_\be_\br_\ba_\bt_\bo_\br. The first word specifies the command to be executed,
- and is passed as argument zero. The remaining words are passed as argu-
- ments to the invoked command.
+ A _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a sequence of optional variable assignments fol-
+ lowed by b\bbl\bla\ban\bnk\bk-separated words and redirections, and terminated by a
+ _\bc_\bo_\bn_\bt_\br_\bo_\bl _\bo_\bp_\be_\br_\ba_\bt_\bo_\br. The first word specifies the command to be executed,
+ and is passed as argument zero. The remaining words are passed as ar-
+ guments to the invoked command.
- The return value of a _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd is its exit status, or 128+_\bn if
+ The return value of a _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd is its exit status, or 128+_\bn if
the command is terminated by signal _\bn.
P\bPi\bip\bpe\bel\bli\bin\bne\bes\bs
- A _\bp_\bi_\bp_\be_\bl_\bi_\bn_\be is a sequence of one or more commands separated by one of
- the control operators |\b| or |\b|&\b&. The format for a pipeline is:
+ A _\bp_\bi_\bp_\be_\bl_\bi_\bn_\be is a sequence of one or more commands separated by one of
+ the control operators |\b| or |\b|&\b&. The format for a pipeline is:
[t\bti\bim\bme\be [-\b-p\bp]] [ ! ] _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 [ [|\b|||\b|&\b&] _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2 ... ]
The standard output of _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 is connected via a pipe to the standard
- input of _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2. This connection is performed before any redirections
- specified by the _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1(see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below). If |\b|&\b& is used, _\bc_\bo_\bm_\b-
- _\bm_\ba_\bn_\bd_\b1's standard error, in addition to its standard output, is con-
- nected to _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2's standard input through the pipe; it is shorthand
- for 2\b2>\b>&\b&1\b1 |\b|. This implicit redirection of the standard error to the
- standard output is performed after any redirections specified by _\bc_\bo_\bm_\b-
+ input of _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2. This connection is performed before any redirec-
+ tions specified by the _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1(see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below). If |\b|&\b& is used,
+ _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1's standard error, in addition to its standard output, is con-
+ nected to _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2's standard input through the pipe; it is shorthand
+ for 2\b2>\b>&\b&1\b1 |\b|. This implicit redirection of the standard error to the
+ standard output is performed after any redirections specified by _\bc_\bo_\bm_\b-
_\bm_\ba_\bn_\bd_\b1.
The return status of a pipeline is the exit status of the last command,
- unless the p\bpi\bip\bpe\bef\bfa\bai\bil\bl option is enabled. If p\bpi\bip\bpe\bef\bfa\bai\bil\bl 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 !\b! 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
+ unless the p\bpi\bip\bpe\bef\bfa\bai\bil\bl option is enabled. If p\bpi\bip\bpe\bef\bfa\bai\bil\bl 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 !\b! 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
before returning a value.
- If the t\bti\bim\bme\be 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 -\b-p\bp option changes the output format to that
- specified by POSIX. When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, it does not recog-
- nize t\bti\bim\bme\be as a reserved word if the next token begins with a `-'. The
- T\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable may be set to a format string that specifies how
- the timing information should be displayed; see the description of
+ If the t\bti\bim\bme\be 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 -\b-p\bp option changes the output format to that
+ specified by POSIX. When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, it does not rec-
+ ognize t\bti\bim\bme\be as a reserved word if the next token begins with a `-'.
+ The T\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable may be set to a format string that specifies
+ how the timing information should be displayed; see the description of
T\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT under S\bSh\bhe\bel\bll\bl V\bVa\bar\bri\bia\bab\bbl\ble\bes\bs below.
When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, t\bti\bim\bme\be 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 T\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable specifies the
+ this case, the shell displays the total user and system time consumed
+ by the shell and its children. The T\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable specifies the
format of the time information.
- Each command in a multi-command pipeline, where pipes are created, is
- executed in a _\bs_\bu_\bb_\bs_\bh_\be_\bl_\bl, which is a separate process. See C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bU-\b-
- T\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT for a description of subshells and a subshell environ-
- ment. If the l\bla\bas\bst\btp\bpi\bip\bpe\be option is enabled using the s\bsh\bho\bop\bpt\bt builtin (see
- the description of s\bsh\bho\bop\bpt\bt below), the last element of a pipeline may be
- run by the shell process when job control is not active.
+ Each command in a multi-command pipeline, where pipes are created, is
+ executed in a _\bs_\bu_\bb_\bs_\bh_\be_\bl_\bl, which is a separate process. See C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bE-\b-
+ C\bCU\bUT\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT for a description of subshells and a subshell envi-
+ ronment. If the l\bla\bas\bst\btp\bpi\bip\bpe\be option is enabled using the s\bsh\bho\bop\bpt\bt builtin
+ (see the description of s\bsh\bho\bop\bpt\bt below), the last element of a pipeline
+ may be run by the shell process when job control is not active.
L\bLi\bis\bst\bts\bs
- A _\bl_\bi_\bs_\bt is a sequence of one or more pipelines separated by one of the
+ A _\bl_\bi_\bs_\bt is a sequence of one or more pipelines separated by one of the
operators ;\b;, &\b&, &\b&&\b&, or |\b||\b|, and optionally terminated by one of ;\b;, &\b&, or
<\b<n\bne\bew\bwl\bli\bin\bne\be>\b>.
Of these list operators, &\b&&\b& and |\b||\b| have equal precedence, followed by ;\b;
and &\b&, which have equal precedence.
- A sequence of one or more newlines may appear in a _\bl_\bi_\bs_\bt instead of a
+ A sequence of one or more newlines may appear in a _\bl_\bi_\bs_\bt instead of a
semicolon to delimit commands.
- If a command is terminated by the control operator &\b&, the shell exe-
- cutes the command in the _\bb_\ba_\bc_\bk_\bg_\br_\bo_\bu_\bn_\bd in a subshell. The shell does not
- wait for the command to finish, and the return status is 0. These are
- referred to as _\ba_\bs_\by_\bn_\bc_\bh_\br_\bo_\bn_\bo_\bu_\bs commands. Commands separated by a ;\b; are ex-
- ecuted sequentially; the shell waits for each command to terminate in
- turn. The return status is the exit status of the last command exe-
+ If a command is terminated by the control operator &\b&, the shell exe-
+ cutes the command in the _\bb_\ba_\bc_\bk_\bg_\br_\bo_\bu_\bn_\bd in a subshell. The shell does not
+ wait for the command to finish, and the return status is 0. These are
+ referred to as _\ba_\bs_\by_\bn_\bc_\bh_\br_\bo_\bn_\bo_\bu_\bs commands. Commands separated by a ;\b; are
+ executed sequentially; the shell waits for each command to terminate in
+ turn. The return status is the exit status of the last command exe-
cuted.
- AND and OR lists are sequences of one or more pipelines separated by
- the &\b&&\b& and |\b||\b| control operators, respectively. AND and OR lists are ex-
- ecuted with left associativity. An AND list has the form
+ AND and OR lists are sequences of one or more pipelines separated by
+ the &\b&&\b& and |\b||\b| control operators, respectively. AND and OR lists are
+ executed with left associativity. An AND list has the form
_\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 &\b&&\b& _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2
- _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2 is executed if, and only if, _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 returns an exit status
+ _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2 is executed if, and only if, _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 returns an exit status
of zero (success).
An OR list has the form
_\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 |\b||\b| _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2
- _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2 is executed if, and only if, _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 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.
+ _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2 is executed if, and only if, _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b1 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.
C\bCo\bom\bmp\bpo\bou\bun\bnd\bd C\bCo\bom\bmm\bma\ban\bnd\bds\bs
- A _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd _\bc_\bo_\bm_\bm_\ba_\bn_\bd is one of the following. In most cases a _\bl_\bi_\bs_\bt 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 _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd _\bc_\bo_\bm_\bm_\ba_\bn_\bd is one of the following. In most cases a _\bl_\bi_\bs_\bt 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.
- (_\bl_\bi_\bs_\bt) _\bl_\bi_\bs_\bt is executed in a subshell (see C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bN-\b-
- M\bME\bEN\bNT\bT below for a description of a subshell environment). Vari-
- able assignments and builtin commands that affect the shell's
+ (_\bl_\bi_\bs_\bt) _\bl_\bi_\bs_\bt is executed in a subshell (see C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bN-\b-
+ M\bME\bEN\bNT\bT below for a description of a subshell environment). Vari-
+ able assignments and builtin commands that affect the shell's
environment do not remain in effect after the command completes.
The return status is the exit status of _\bl_\bi_\bs_\bt.
{ _\bl_\bi_\bs_\bt; }
- _\bl_\bi_\bs_\bt is simply executed in the current shell environment. _\bl_\bi_\bs_\bt
- must be terminated with a newline or semicolon. This is known as
- a _\bg_\br_\bo_\bu_\bp _\bc_\bo_\bm_\bm_\ba_\bn_\bd. The return status is the exit status of _\bl_\bi_\bs_\bt.
- Note that unlike the metacharacters (\b( and )\b), {\b{ and }\b} are _\br_\be_\b-
- _\bs_\be_\br_\bv_\be_\bd _\bw_\bo_\br_\bd_\bs 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 _\bl_\bi_\bs_\bt by whitespace or another shell
+ _\bl_\bi_\bs_\bt is simply executed in the current shell environment. _\bl_\bi_\bs_\bt
+ must be terminated with a newline or semicolon. This is known
+ as a _\bg_\br_\bo_\bu_\bp _\bc_\bo_\bm_\bm_\ba_\bn_\bd. The return status is the exit status of
+ _\bl_\bi_\bs_\bt. Note that unlike the metacharacters (\b( and )\b), {\b{ and }\b} are
+ _\br_\be_\bs_\be_\br_\bv_\be_\bd _\bw_\bo_\br_\bd_\bs 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 _\bl_\bi_\bs_\bt by whitespace or another shell
metacharacter.
((_\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn))
The _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn is evaluated according to the rules described be-
- low under A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN. If the value of the expression
+ low under A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN. If the value of the expression
is non-zero, the return status is 0; otherwise the return status
- is 1. The _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn undergoes the same expansions as if it were
- within double quotes, but double quote characters in _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn
- are not treated specially and are removed.
+ is 1. The _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn undergoes the same expansions as if it
+ were within double quotes, but double quote characters in _\be_\bx_\b-
+ _\bp_\br_\be_\bs_\bs_\bi_\bo_\bn are not treated specially and are removed.
[\b[[\b[ _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn ]\b]]\b]
- Return a status of 0 or 1 depending on the evaluation of the
- conditional expression _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn. Expressions are composed of
- the primaries described below under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS. The
- words between the [\b[[\b[ and ]\b]]\b] do not undergo word splitting and
- pathname expansion. The shell performs tilde expansion, parame-
- ter and variable expansion, arithmetic expansion, command sub-
- stitution, process substitution, and quote removal on those
- words (the expansions that would occur if the words were en-
- closed in double quotes). Conditional operators such as -\b-f\bf must
+ Return a status of 0 or 1 depending on the evaluation of the
+ conditional expression _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn. Expressions are composed of
+ the primaries described below under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS.
+ The words between the [\b[[\b[ and ]\b]]\b] do not undergo word splitting
+ and pathname expansion. The shell performs tilde expansion, pa-
+ rameter and variable expansion, arithmetic expansion, command
+ substitution, process substitution, and quote removal on those
+ words (the expansions that would occur if the words were en-
+ closed in double quotes). Conditional operators such as -\b-f\bf must
be unquoted to be recognized as primaries.
- When used with [\b[[\b[, the <\b< and >\b> operators sort lexicographically
+ When used with [\b[[\b[, the <\b< and >\b> operators sort lexicographically
using the current locale.
- When the =\b==\b= and !\b!=\b= operators are used, the string to the right
+ When the =\b==\b= and !\b!=\b= operators are used, the string to the right
of the operator is considered a pattern and matched according to
the rules described below under P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg, as if the e\bex\bxt\bt-\b-
- g\bgl\blo\bob\bb shell option were enabled. The =\b= operator is equivalent to
- =\b==\b=. If the n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh shell option is enabled, the match is
- performed without regard to the case of alphabetic characters.
- The return value is 0 if the string matches (=\b==\b=) or does not
- match (!\b!=\b=) the pattern, 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, =\b=~\b~, is available, with the same
- precedence as =\b==\b= and !\b!=\b=. When it is used, the string to the
+ g\bgl\blo\bob\bb shell option were enabled. The =\b= operator is equivalent to
+ =\b==\b=. If the n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh shell option is enabled, the match is
+ performed without regard to the case of alphabetic characters.
+ The return value is 0 if the string matches (=\b==\b=) or does not
+ match (!\b!=\b=) the pattern, and 1 otherwise. Any part of the pat-
+ tern may be quoted to force the quoted portion to be matched as
+ a string.
+
+ An additional binary operator, =\b=~\b~, is available, with the same
+ precedence as =\b==\b= and !\b!=\b=. When it is used, the string to the
right of the operator is considered a POSIX extended regular ex-
- pression and matched accordingly (using the POSIX _\br_\be_\bg_\bc_\bo_\bm_\bp and
- _\br_\be_\bg_\be_\bx_\be_\bc interfaces usually described in _\br_\be_\bg_\be_\bx(3)). The return
- value is 0 if the string matches the pattern, and 1 otherwise.
+ pression and matched accordingly (using the POSIX _\br_\be_\bg_\bc_\bo_\bm_\bp and
+ _\br_\be_\bg_\be_\bx_\be_\bc interfaces usually described in _\br_\be_\bg_\be_\bx(3)). The return
+ value is 0 if the string matches the pattern, and 1 otherwise.
If the regular expression is syntactically incorrect, the condi-
- tional expression's return value is 2. If the n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh shell
- option is enabled, the match is performed without regard to the
- case of alphabetic characters. If any part of the pattern is
- quoted, the quoted portion is matched literally. This means ev-
- ery character in the quoted portion matches itself, instead of
- having any special pattern matching meaning. If the pattern is
- stored in a shell variable, quoting the variable expansion
- forces the entire pattern to be matched literally. Treat bracket
- expressions in regular expressions carefully, since normal quot-
- ing and pattern characters lose their meanings between brackets.
-
- The pattern will match if it matches any part of the string. An-
- chor the pattern using the ^\b^ and $\b$ regular expression operators
- to force it to match the entire string. The array variable
+ tional expression's return value is 2. If the n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh shell
+ option is enabled, the match is performed without regard to the
+ case of alphabetic characters. If any part of the pattern is
+ quoted, the quoted portion is matched literally. This means ev-
+ ery character in the quoted portion matches itself, instead of
+ having any special pattern matching meaning. If the pattern is
+ stored in a shell variable, quoting the variable expansion
+ forces the entire pattern to be matched literally. Treat
+ bracket expressions in regular expressions carefully, since nor-
+ mal quoting and pattern characters lose their meanings between
+ brackets.
+
+ The pattern will match if it matches any part of the string.
+ Anchor the pattern using the ^\b^ and $\b$ regular expression opera-
+ tors to force it to match the entire string. The array variable
B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH records which parts of the string matched the pat-
- tern. The element of B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH with index 0 contains the por-
- tion of the string matching the entire regular expression. Sub-
- strings matched by parenthesized subexpressions within the regu-
- lar expression are saved in the remaining B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH indices.
- The element of B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH with index _\bn is the portion of the
- string matching the _\bnth parenthesized subexpression. B\bBa\bas\bsh\bh sets
- B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH in the global scope; declaring it as a local vari-
- able will lead to unexpected results.
+ tern. The element of B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH with index 0 contains the
+ portion of the string matching the entire regular expression.
+ Substrings matched by parenthesized subexpressions within the
+ regular expression are saved in the remaining B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH in-
+ dices. The element of B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH with index _\bn is the portion
+ of the string matching the _\bnth parenthesized subexpression.
+ B\bBa\bas\bsh\bh sets B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH in the global scope; declaring it as a
+ local variable will lead to unexpected results.
Expressions may be combined using the following operators,
listed in decreasing order of precedence:
f\bfo\bor\br _\bn_\ba_\bm_\be [ [ i\bin\bn [ _\bw_\bo_\br_\bd _\b._\b._\b. ] ] ; ] d\bdo\bo _\bl_\bi_\bs_\bt ; d\bdo\bon\bne\be
The list of words following i\bin\bn is expanded, generating a list of
items. The variable _\bn_\ba_\bm_\be is set to each element of this list in
- turn, and _\bl_\bi_\bs_\bt is executed each time. If the i\bin\bn _\bw_\bo_\br_\bd is omitted,
- the f\bfo\bor\br command executes _\bl_\bi_\bs_\bt once for each positional parameter
- that is set (see P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS below). The return status is the
- exit status of the last command that executes. If the expansion
- of the items following i\bin\bn results in an empty list, no commands
- are executed, and the return status is 0.
+ turn, and _\bl_\bi_\bs_\bt is executed each time. If the i\bin\bn _\bw_\bo_\br_\bd is omit-
+ ted, the f\bfo\bor\br command executes _\bl_\bi_\bs_\bt once for each positional pa-
+ rameter that is set (see P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS below). The return status
+ is the exit status of the last command that executes. If the
+ expansion of the items following i\bin\bn results in an empty list, no
+ commands are executed, and the return status is 0.
f\bfo\bor\br (( _\be_\bx_\bp_\br_\b1 ; _\be_\bx_\bp_\br_\b2 ; _\be_\bx_\bp_\br_\b3 )) ; d\bdo\bo _\bl_\bi_\bs_\bt ; d\bdo\bon\bne\be
First, the arithmetic expression _\be_\bx_\bp_\br_\b1 is evaluated according to
- the rules described below under A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN. The
+ the rules described below under A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN. The
arithmetic expression _\be_\bx_\bp_\br_\b2 is then evaluated repeatedly until
- it evaluates to zero. Each time _\be_\bx_\bp_\br_\b2 evaluates to a non-zero
+ it evaluates to zero. Each time _\be_\bx_\bp_\br_\b2 evaluates to a non-zero
value, _\bl_\bi_\bs_\bt is executed and the arithmetic expression _\be_\bx_\bp_\br_\b3 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
+ 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 _\bl_\bi_\bs_\bt that is executed, or false if any of the expres-
sions is invalid.
s\bse\bel\ble\bec\bct\bt _\bn_\ba_\bm_\be [ i\bin\bn _\bw_\bo_\br_\bd ] ; d\bdo\bo _\bl_\bi_\bs_\bt ; d\bdo\bon\bne\be
The list of words following i\bin\bn is expanded, generating a list of
items, and the set of expanded words is printed on the standard
- error, each preceded by a number. If the i\bin\bn _\bw_\bo_\br_\bd is omitted, the
- positional parameters are printed (see P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS below). s\bse\bel\ble\bec\bct\bt
- then displays the P\bPS\bS3\b3 prompt and reads a line from the standard
- input. If the line consists of a number corresponding to one of
- the displayed words, then the value of _\bn_\ba_\bm_\be is set to that word.
- If the line is empty, the words and prompt are displayed again.
- If EOF is read, the s\bse\bel\ble\bec\bct\bt command completes and returns 1. Any
- other value read causes _\bn_\ba_\bm_\be to be set to null. The line read is
- saved in the variable R\bRE\bEP\bPL\bLY\bY. The _\bl_\bi_\bs_\bt is executed after each se-
- lection until a b\bbr\bre\bea\bak\bk command is executed. The exit status of
- s\bse\bel\ble\bec\bct\bt is the exit status of the last command executed in _\bl_\bi_\bs_\bt,
- or zero if no commands were executed.
+ error, each preceded by a number. If the i\bin\bn _\bw_\bo_\br_\bd is omitted,
+ the positional parameters are printed (see P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS below).
+ s\bse\bel\ble\bec\bct\bt then displays the P\bPS\bS3\b3 prompt and reads a line from the
+ standard input. If the line consists of a number corresponding
+ to one of the displayed words, then the value of _\bn_\ba_\bm_\be is set to
+ that word. If the line is empty, the words and prompt are dis-
+ played again. If EOF is read, the s\bse\bel\ble\bec\bct\bt command completes and
+ returns 1. Any other value read causes _\bn_\ba_\bm_\be to be set to null.
+ The line read is saved in the variable R\bRE\bEP\bPL\bLY\bY. The _\bl_\bi_\bs_\bt is exe-
+ cuted after each selection until a b\bbr\bre\bea\bak\bk command is executed.
+ The exit status of s\bse\bel\ble\bec\bct\bt is the exit status of the last command
+ executed in _\bl_\bi_\bs_\bt, or zero if no commands were executed.
c\bca\bas\bse\be _\bw_\bo_\br_\bd i\bin\bn [ [(] _\bp_\ba_\bt_\bt_\be_\br_\bn [ |\b| _\bp_\ba_\bt_\bt_\be_\br_\bn ] ... ) _\bl_\bi_\bs_\bt ;; ] ... e\bes\bsa\bac\bc
A c\bca\bas\bse\be command first expands _\bw_\bo_\br_\bd, and tries to match it against
each _\bp_\ba_\bt_\bt_\be_\br_\bn in turn, using the matching rules described under
- P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. The _\bw_\bo_\br_\bd is expanded using tilde expan-
+ P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. The _\bw_\bo_\br_\bd is expanded using tilde expan-
sion, parameter and variable expansion, arithmetic expansion,
command substitution, process substitution and quote removal.
Each _\bp_\ba_\bt_\bt_\be_\br_\bn examined is expanded using tilde expansion, parame-
ter and variable expansion, arithmetic expansion, command sub-
- stitution, process substitution, and quote removal. If the n\bno\bo-\b-
+ stitution, process substitution, and quote removal. If the n\bno\bo-\b-
c\bca\bas\bse\bem\bma\bat\btc\bch\bh shell option is enabled, the match is performed with-
- out regard to the case of alphabetic characters. When a match is
- found, the corresponding _\bl_\bi_\bs_\bt is executed. If the ;\b;;\b; operator is
- used, no subsequent matches are attempted after the first pat-
- tern match. Using ;\b;&\b& in place of ;\b;;\b; causes execution to continue
- with the _\bl_\bi_\bs_\bt associated with the next set of patterns. Using
- ;\b;;\b;&\b& in place of ;\b;;\b; causes the shell to test the next pattern
- list in the statement, if any, and execute any associated _\bl_\bi_\bs_\bt
- on a successful match, continuing the case statement execution
- as if the pattern list had not matched. The exit status is zero
- if no pattern matches. Otherwise, it is the exit status of the
- last command executed in _\bl_\bi_\bs_\bt.
+ out regard to the case of alphabetic characters. When a match
+ is found, the corresponding _\bl_\bi_\bs_\bt is executed. If the ;\b;;\b; opera-
+ tor is used, no subsequent matches are attempted after the first
+ pattern match. Using ;\b;&\b& in place of ;\b;;\b; causes execution to con-
+ tinue with the _\bl_\bi_\bs_\bt associated with the next set of patterns.
+ Using ;\b;;\b;&\b& in place of ;\b;;\b; causes the shell to test the next pat-
+ tern list in the statement, if any, and execute any associated
+ _\bl_\bi_\bs_\bt on a successful match, continuing the case statement execu-
+ tion as if the pattern list had not matched. The exit status is
+ zero if no pattern matches. Otherwise, it is the exit status of
+ the last command executed in _\bl_\bi_\bs_\bt.
i\bif\bf _\bl_\bi_\bs_\bt; t\bth\bhe\ben\bn _\bl_\bi_\bs_\bt; [ e\bel\bli\bif\bf _\bl_\bi_\bs_\bt; t\bth\bhe\ben\bn _\bl_\bi_\bs_\bt; ] ... [ e\bel\bls\bse\be _\bl_\bi_\bs_\bt; ] f\bfi\bi
- The i\bif\bf _\bl_\bi_\bs_\bt is executed. If its exit status is zero, the t\bth\bhe\ben\bn
- _\bl_\bi_\bs_\bt is executed. Otherwise, each e\bel\bli\bif\bf _\bl_\bi_\bs_\bt is executed in turn,
- and if its exit status is zero, the corresponding t\bth\bhe\ben\bn _\bl_\bi_\bs_\bt is
- executed and the command completes. Otherwise, the e\bel\bls\bse\be _\bl_\bi_\bs_\bt is
- executed, if present. The exit status is the exit status of the
- last command executed, or zero if no condition tested true.
+ The i\bif\bf _\bl_\bi_\bs_\bt is executed. If its exit status is zero, the t\bth\bhe\ben\bn
+ _\bl_\bi_\bs_\bt is executed. Otherwise, each e\bel\bli\bif\bf _\bl_\bi_\bs_\bt is executed in
+ turn, and if its exit status is zero, the corresponding t\bth\bhe\ben\bn
+ _\bl_\bi_\bs_\bt is executed and the command completes. Otherwise, the e\bel\bls\bse\be
+ _\bl_\bi_\bs_\bt is executed, if present. The exit status is the exit sta-
+ tus of the last command executed, or zero if no condition tested
+ true.
w\bwh\bhi\bil\ble\be _\bl_\bi_\bs_\bt_\b-_\b1; d\bdo\bo _\bl_\bi_\bs_\bt_\b-_\b2; d\bdo\bon\bne\be
u\bun\bnt\bti\bil\bl _\bl_\bi_\bs_\bt_\b-_\b1; d\bdo\bo _\bl_\bi_\bs_\bt_\b-_\b2; d\bdo\bon\bne\be
- The w\bwh\bhi\bil\ble\be command continuously executes the list _\bl_\bi_\bs_\bt_\b-_\b2 as long
+ The w\bwh\bhi\bil\ble\be command continuously executes the list _\bl_\bi_\bs_\bt_\b-_\b2 as long
as the last command in the list _\bl_\bi_\bs_\bt_\b-_\b1 returns an exit status of
- zero. The u\bun\bnt\bti\bil\bl command is identical to the w\bwh\bhi\bil\ble\be command, ex-
+ zero. The u\bun\bnt\bti\bil\bl command is identical to the w\bwh\bhi\bil\ble\be command, ex-
cept that the test is negated: _\bl_\bi_\bs_\bt_\b-_\b2 is executed as long as the
- last command in _\bl_\bi_\bs_\bt_\b-_\b1 returns a non-zero exit status. The exit
+ last command in _\bl_\bi_\bs_\bt_\b-_\b1 returns a non-zero exit status. The exit
status of the w\bwh\bhi\bil\ble\be and u\bun\bnt\bti\bil\bl commands is the exit status of the
last command executed in _\bl_\bi_\bs_\bt_\b-_\b2, or zero if none was executed.
C\bCo\bop\bpr\bro\boc\bce\bes\bss\bse\bes\bs
A _\bc_\bo_\bp_\br_\bo_\bc_\be_\bs_\bs is a shell command preceded by the c\bco\bop\bpr\bro\boc\bc reserved word. A
- coprocess is executed asynchronously in a subshell, as if the command
- had been terminated with the &\b& control operator, with a two-way pipe
+ coprocess is executed asynchronously in a subshell, as if the command
+ had been terminated with the &\b& control operator, with a two-way pipe
established between the executing shell and the coprocess.
The syntax for a coprocess is:
c\bco\bop\bpr\bro\boc\bc [_\bN_\bA_\bM_\bE] _\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\br_\be_\bd_\bi_\br_\be_\bc_\bt_\bi_\bo_\bn_\bs]
- This creates a coprocess named _\bN_\bA_\bM_\bE. _\bc_\bo_\bm_\bm_\ba_\bn_\bd may be either a simple
- command or a compound command (see above). _\bN_\bA_\bM_\bE is a shell variable
- name. If _\bN_\bA_\bM_\bE is not supplied, the default name is C\bCO\bOP\bPR\bRO\bOC\bC.
+ This creates a coprocess named _\bN_\bA_\bM_\bE. _\bc_\bo_\bm_\bm_\ba_\bn_\bd may be either a simple
+ command or a compound command (see above). _\bN_\bA_\bM_\bE is a shell variable
+ name. If _\bN_\bA_\bM_\bE is not supplied, the default name is C\bCO\bOP\bPR\bRO\bOC\bC.
The recommended form to use for a coprocess is
c\bco\bop\bpr\bro\boc\bc _\bN_\bA_\bM_\bE { _\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\br_\be_\bd_\bi_\br_\be_\bc_\bt_\bi_\bo_\bn_\bs]; }
- This form is recommended because simple commands result in the copro-
- cess always being named C\bCO\bOP\bPR\bRO\bOC\bC, and it is simpler to use and more com-
+ This form is recommended because simple commands result in the copro-
+ cess always being named C\bCO\bOP\bPR\bRO\bOC\bC, and it is simpler to use and more com-
plete than the other compound commands.
- If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a compound command, _\bN_\bA_\bM_\bE is optional. The word following
- c\bco\bop\bpr\bro\boc\bc determines whether that word is interpreted as a variable name:
- it is interpreted as _\bN_\bA_\bM_\bE if it is not a reserved word that introduces
- a compound command. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a simple command, _\bN_\bA_\bM_\bE is not al-
- lowed; this is to avoid confusion between _\bN_\bA_\bM_\bE and the first word of
+ If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a compound command, _\bN_\bA_\bM_\bE is optional. The word following
+ c\bco\bop\bpr\bro\boc\bc determines whether that word is interpreted as a variable name:
+ it is interpreted as _\bN_\bA_\bM_\bE if it is not a reserved word that introduces
+ a compound command. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a simple command, _\bN_\bA_\bM_\bE is not al-
+ lowed; this is to avoid confusion between _\bN_\bA_\bM_\bE and the first word of
the simple command.
- When the coprocess is executed, the shell creates an array variable
- (see A\bAr\brr\bra\bay\bys\bs below) named _\bN_\bA_\bM_\bE in the context of the executing shell.
- The standard output of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is connected via a pipe to a file de-
- scriptor in the executing shell, and that file descriptor is assigned
- to _\bN_\bA_\bM_\bE[0]. The standard input of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is connected via a pipe to a
+ When the coprocess is executed, the shell creates an array variable
+ (see A\bAr\brr\bra\bay\bys\bs below) named _\bN_\bA_\bM_\bE in the context of the executing shell.
+ The standard output of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is connected via a pipe to a file de-
+ scriptor in the executing shell, and that file descriptor is assigned
+ to _\bN_\bA_\bM_\bE[0]. The standard input of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is connected via a pipe to a
file descriptor in the executing shell, and that file descriptor is as-
- signed to _\bN_\bA_\bM_\bE[1]. This pipe is established before any redirections
- specified by the command (see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below). The file descriptors
- can be utilized as arguments to shell commands and redirections using
- standard word expansions. Other than those created to execute command
- and process substitutions, the file descriptors are not available in
+ signed to _\bN_\bA_\bM_\bE[1]. This pipe is established before any redirections
+ specified by the command (see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below). The file descriptors
+ can be utilized as arguments to shell commands and redirections using
+ standard word expansions. Other than those created to execute command
+ and process substitutions, the file descriptors are not available in
subshells.
- The process ID of the shell spawned to execute the coprocess is avail-
- able as the value of the variable _\bN_\bA_\bM_\bE_PID. The w\bwa\bai\bit\bt builtin command
+ The process ID of the shell spawned to execute the coprocess is avail-
+ able as the value of the variable _\bN_\bA_\bM_\bE_PID. The w\bwa\bai\bit\bt builtin command
may be used to wait for the coprocess to terminate.
- Since the coprocess is created as an asynchronous command, the c\bco\bop\bpr\bro\boc\bc
- command always returns success. The return status of a coprocess is the
- exit status of _\bc_\bo_\bm_\bm_\ba_\bn_\bd.
+ Since the coprocess is created as an asynchronous command, the c\bco\bop\bpr\bro\boc\bc
+ command always returns success. The return status of a coprocess is
+ the exit status of _\bc_\bo_\bm_\bm_\ba_\bn_\bd.
S\bSh\bhe\bel\bll\bl F\bFu\bun\bnc\bct\bti\bio\bon\bn D\bDe\bef\bfi\bin\bni\bit\bti\bio\bon\bns\bs
- 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:
_\bf_\bn_\ba_\bm_\be () _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\br_\be_\bd_\bi_\br_\be_\bc_\bt_\bi_\bo_\bn]
f\bfu\bun\bnc\bct\bti\bio\bon\bn _\bf_\bn_\ba_\bm_\be [()] _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\br_\be_\bd_\bi_\br_\be_\bc_\bt_\bi_\bo_\bn]
- This defines a function named _\bf_\bn_\ba_\bm_\be. The reserved word f\bfu\bun\bnc\bct\bti\bio\bon\bn
- is optional. If the f\bfu\bun\bnc\bct\bti\bio\bon\bn reserved word is supplied, the
- parentheses are optional. The _\bb_\bo_\bd_\by of the function is the com-
- pound command _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd (see C\bCo\bom\bmp\bpo\bou\bun\bnd\bd C\bCo\bom\bmm\bma\ban\bnd\bds\bs above).
- That command is usually a _\bl_\bi_\bs_\bt of commands between { and }, but
- may be any command listed under C\bCo\bom\bmp\bpo\bou\bun\bnd\bd C\bCo\bom\bmm\bma\ban\bnd\bds\bs above. If the
+ This defines a function named _\bf_\bn_\ba_\bm_\be. The reserved word f\bfu\bun\bnc\bct\bti\bio\bon\bn
+ is optional. If the f\bfu\bun\bnc\bct\bti\bio\bon\bn reserved word is supplied, the
+ parentheses are optional. The _\bb_\bo_\bd_\by of the function is the com-
+ pound command _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd (see C\bCo\bom\bmp\bpo\bou\bun\bnd\bd C\bCo\bom\bmm\bma\ban\bnd\bds\bs above).
+ That command is usually a _\bl_\bi_\bs_\bt of commands between { and }, but
+ may be any command listed under C\bCo\bom\bmp\bpo\bou\bun\bnd\bd C\bCo\bom\bmm\bma\ban\bnd\bds\bs above. If the
f\bfu\bun\bnc\bct\bti\bio\bon\bn reserved word is used, but the parentheses are not sup-
- plied, the braces are recommended. _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd is executed
- whenever _\bf_\bn_\ba_\bm_\be is specified as the name of a simple command.
+ plied, the braces are recommended. _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd is executed
+ whenever _\bf_\bn_\ba_\bm_\be is specified as the name of a simple command.
When in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, _\bf_\bn_\ba_\bm_\be must be a valid shell _\bn_\ba_\bm_\be and may not
- be the name of one of the POSIX _\bs_\bp_\be_\bc_\bi_\ba_\bl _\bb_\bu_\bi_\bl_\bt_\bi_\bn_\bs. In default
- mode, a function name can be any unquoted shell word that does
- not contain $\b$. Any redirections (see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below) speci-
- fied 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 executed, the exit status of a
- function is the exit status of the last command executed in the
- body. (See F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS below.)
+ be the name of one of the POSIX _\bs_\bp_\be_\bc_\bi_\ba_\bl _\bb_\bu_\bi_\bl_\bt_\bi_\bn_\bs. In default
+ mode, a function name can be any unquoted shell word that does
+ not contain $\b$. Any redirections (see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below) speci-
+ fied 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 executed, the exit status of a
+ function is the exit status of the last command executed in the
+ body. (See F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS below.)
C\bCO\bOM\bMM\bME\bEN\bNT\bTS\bS
In a non-interactive shell, or an interactive shell in which the i\bin\bnt\bte\ber\br-\b-
- a\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs option to the s\bsh\bho\bop\bpt\bt builtin is enabled (see S\bSH\bHE\bEL\bLL\bL
- B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below), a word beginning with #\b# causes that word and
- all remaining characters on that line to be ignored. An interactive
- shell without the i\bin\bnt\bte\ber\bra\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs option enabled does not allow
- comments. The i\bin\bnt\bte\ber\bra\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs option is on by default in interac-
+ a\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs option to the s\bsh\bho\bop\bpt\bt builtin is enabled (see S\bSH\bHE\bEL\bLL\bL
+ B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below), a word beginning with #\b# causes that word and
+ all remaining characters on that line to be ignored. An interactive
+ shell without the i\bin\bnt\bte\ber\bra\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs option enabled does not allow
+ comments. The i\bin\bnt\bte\ber\bra\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs option is on by default in interac-
tive shells.
Q\bQU\bUO\bOT\bTI\bIN\bNG\bG
- _\bQ_\bu_\bo_\bt_\bi_\bn_\bg is used to remove the special meaning of certain characters or
- words to the shell. Quoting can be used to disable special treatment
+ _\bQ_\bu_\bo_\bt_\bi_\bn_\bg 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 _\bm_\be_\bt_\ba_\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br_\bs listed above under D\bDE\bEF\bFI\bIN\bNI\bIT\bTI\bIO\bON\bNS\bS has special
+ Each of the _\bm_\be_\bt_\ba_\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br_\bs listed above under D\bDE\bEF\bFI\bIN\bNI\bIT\bTI\bIO\bON\bNS\bS 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 H\bHI\bIS\bS-\b-
+ When the command history expansion facilities are being used (see H\bHI\bIS\bS-\b-
T\bTO\bOR\bRY\bY E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN below), the _\bh_\bi_\bs_\bt_\bo_\br_\by _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn character, usually !\b!, must
be quoted to prevent history expansion.
- There are three quoting mechanisms: the _\be_\bs_\bc_\ba_\bp_\be _\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br, single
+ There are three quoting mechanisms: the _\be_\bs_\bc_\ba_\bp_\be _\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br, single
quotes, and double quotes.
- A non-quoted backslash (\\b\) is the _\be_\bs_\bc_\ba_\bp_\be _\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br. It preserves the
+ A non-quoted backslash (\\b\) is the _\be_\bs_\bc_\ba_\bp_\be _\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br. It preserves the
literal value of the next character that follows, with the exception of
- <newline>. If a \\b\<newline> pair appears, and the backslash is not it-
+ <newline>. If a \\b\<newline> pair appears, and the backslash is not it-
self quoted, the \\b\<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
- each character within the quotes. A single quote may not occur between
+ 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 $\b$, `\b`, \\b\, and,
- when history expansion is enabled, !\b!. When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be,
- the !\b! has no special meaning within double quotes, even when history
- expansion is enabled. The characters $\b$ and `\b` retain their special mean-
- ing within double quotes. The backslash retains its special meaning
- only when followed by one of the following characters: $\b$, `\b`, "\b", \\b\, or
- <\b<n\bne\bew\bwl\bli\bin\bne\be>\b>. A double quote may be quoted within double quotes by preced-
- ing it with a backslash. If enabled, history expansion will be per-
- formed unless an !\b! appearing in double quotes is escaped using a back-
- slash. The backslash preceding the !\b! is not removed.
-
- The special parameters *\b* and @\b@ have special meaning when in double
+ Enclosing characters in double quotes preserves the literal value of
+ all characters within the quotes, with the exception of $\b$, `\b`, \\b\, and,
+ when history expansion is enabled, !\b!. When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be,
+ the !\b! has no special meaning within double quotes, even when history
+ expansion is enabled. The characters $\b$ and `\b` retain their special
+ meaning within double quotes. The backslash retains its special mean-
+ ing only when followed by one of the following characters: $\b$, `\b`, "\b", \\b\,
+ or <\b<n\bne\bew\bwl\bli\bin\bne\be>\b>. A double quote may be quoted within double quotes by
+ preceding it with a backslash. If enabled, history expansion will be
+ performed unless an !\b! appearing in double quotes is escaped using a
+ backslash. The backslash preceding the !\b! is not removed.
+
+ The special parameters *\b* and @\b@ have special meaning when in double
quotes (see P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS below).
- Character sequences of the form $\b$'_\bs_\bt_\br_\bi_\bn_\bg' are treated as a special
- variant of single quotes. The sequence expands to _\bs_\bt_\br_\bi_\bn_\bg, with back-
- slash-escaped characters in _\bs_\bt_\br_\bi_\bn_\bg replaced as specified by the ANSI C
- standard. Backslash escape sequences, if present, are decoded as fol-
+ Character sequences of the form $\b$'_\bs_\bt_\br_\bi_\bn_\bg' are treated as a special
+ variant of single quotes. The sequence expands to _\bs_\bt_\br_\bi_\bn_\bg, with back-
+ slash-escaped characters in _\bs_\bt_\br_\bi_\bn_\bg replaced as specified by the ANSI C
+ standard. Backslash escape sequences, if present, are decoded as fol-
lows:
\\b\a\ba alert (bell)
\\b\b\bb backspace
\\b\'\b' single quote
\\b\"\b" double quote
\\b\?\b? question mark
- \\b\_\bn_\bn_\bn the eight-bit character whose value is the octal value
+ \\b\_\bn_\bn_\bn the eight-bit character whose value is the octal value
_\bn_\bn_\bn (one to three octal digits)
- \\b\x\bx_\bH_\bH the eight-bit character whose value is the hexadecimal
+ \\b\x\bx_\bH_\bH the eight-bit character whose value is the hexadecimal
value _\bH_\bH (one or two hex digits)
- \\b\u\bu_\bH_\bH_\bH_\bH the Unicode (ISO/IEC 10646) character whose value is the
+ \\b\u\bu_\bH_\bH_\bH_\bH the Unicode (ISO/IEC 10646) character whose value is the
hexadecimal value _\bH_\bH_\bH_\bH (one to four hex digits)
\\b\U\bU_\bH_\bH_\bH_\bH_\bH_\bH_\bH_\bH
- the Unicode (ISO/IEC 10646) character whose value is the
+ the Unicode (ISO/IEC 10646) character whose value is the
hexadecimal value _\bH_\bH_\bH_\bH_\bH_\bH_\bH_\bH (one to eight hex digits)
\\b\c\bc_\bx a control-_\bx 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 ($\b$"_\bs_\bt_\br_\bi_\bn_\bg") will cause
- the string to be translated according to the current locale. The _\bg_\be_\bt_\b-
- _\bt_\be_\bx_\bt infrastructure performs the lookup and translation, using the
- L\bLC\bC_\b_M\bME\bES\bSS\bSA\bAG\bGE\bES\bS, T\bTE\bEX\bXT\bTD\bDO\bOM\bMA\bAI\bIN\bND\bDI\bIR\bR, and T\bTE\bEX\bXT\bTD\bDO\bOM\bMA\bAI\bIN\bN shell variables. If the cur-
- rent locale is C\bC or P\bPO\bOS\bSI\bIX\bX, if there are no translations available, or
- if the string is not translated, the dollar sign is ignored. This is a
- form of double quoting, so the string remains double-quoted by default,
- whether or not it is translated and replaced. If the n\bno\boe\bex\bxp\bpa\ban\bnd\bd_\b_t\btr\bra\ban\bns\bsl\bla\ba-\b-
- t\bti\bio\bon\bn option is enabled using the s\bsh\bho\bop\bpt\bt builtin, translated strings are
- single-quoted instead of double-quoted. See the description of s\bsh\bho\bop\bpt\bt
- below under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS.
+ the string to be translated according to the current locale. The _\bg_\be_\bt_\b-
+ _\bt_\be_\bx_\bt infrastructure performs the lookup and translation, using the
+ L\bLC\bC_\b_M\bME\bES\bSS\bSA\bAG\bGE\bES\bS, T\bTE\bEX\bXT\bTD\bDO\bOM\bMA\bAI\bIN\bND\bDI\bIR\bR, and T\bTE\bEX\bXT\bTD\bDO\bOM\bMA\bAI\bIN\bN shell variables. If the
+ current locale is C\bC or P\bPO\bOS\bSI\bIX\bX, if there are no translations available,
+ or if the string is not translated, the dollar sign is ignored. This
+ is a form of double quoting, so the string remains double-quoted by de-
+ fault, whether or not it is translated and replaced. If the n\bno\boe\bex\bx-\b-
+ p\bpa\ban\bnd\bd_\b_t\btr\bra\ban\bns\bsl\bla\bat\bti\bio\bon\bn option is enabled using the s\bsh\bho\bop\bpt\bt builtin, translated
+ strings are single-quoted instead of double-quoted. See the descrip-
+ tion of s\bsh\bho\bop\bpt\bt below under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS.
P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS
- A _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an entity that stores values. It can be a _\bn_\ba_\bm_\be, a num-
+ A _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an entity that stores values. It can be a _\bn_\ba_\bm_\be, a num-
ber, or one of the special characters listed below under S\bSp\bpe\bec\bci\bia\bal\bl P\bPa\bar\bra\bam\bm-\b-
- e\bet\bte\ber\brs\bs. A _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be is a parameter denoted by a _\bn_\ba_\bm_\be. A variable has a
- _\bv_\ba_\bl_\bu_\be and zero or more _\ba_\bt_\bt_\br_\bi_\bb_\bu_\bt_\be_\bs. Attributes are assigned using the
+ e\bet\bte\ber\brs\bs. A _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be is a parameter denoted by a _\bn_\ba_\bm_\be. A variable has a
+ _\bv_\ba_\bl_\bu_\be and zero or more _\ba_\bt_\bt_\br_\bi_\bb_\bu_\bt_\be_\bs. Attributes are assigned using the
d\bde\bec\bcl\bla\bar\bre\be builtin command (see d\bde\bec\bcl\bla\bar\bre\be below in S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS).
- 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 parameter is set if it has been assigned a value. The null string is
+ a valid value. Once a variable is set, it may be unset only by using
the u\bun\bns\bse\bet\bt builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
A _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be may be assigned to by a statement of the form
_\bn_\ba_\bm_\be=[_\bv_\ba_\bl_\bu_\be]
- If _\bv_\ba_\bl_\bu_\be is not given, the variable is assigned the null string. All
- _\bv_\ba_\bl_\bu_\be_\bs undergo tilde expansion, parameter and variable expansion, com-
- mand substitution, arithmetic expansion, and quote removal (see E\bEX\bXP\bPA\bAN\bN-\b-
- S\bSI\bIO\bON\bN below). If the variable has its i\bin\bnt\bte\beg\bge\ber\br attribute set, then _\bv_\ba_\bl_\bu_\be
+ If _\bv_\ba_\bl_\bu_\be is not given, the variable is assigned the null string. All
+ _\bv_\ba_\bl_\bu_\be_\bs undergo tilde expansion, parameter and variable expansion, com-
+ mand substitution, arithmetic expansion, and quote removal (see E\bEX\bXP\bPA\bAN\bN-\b-
+ S\bSI\bIO\bON\bN below). If the variable has its i\bin\bnt\bte\beg\bge\ber\br attribute set, then _\bv_\ba_\bl_\bu_\be
is evaluated as an arithmetic expression even if the $((...)) expansion
- is not used (see A\bAr\bri\bit\bth\bhm\bme\bet\bti\bic\bc E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn below). Word splitting and path-
- name expansion are not performed. Assignment statements may also appear
- as arguments to the a\bal\bli\bia\bas\bs, d\bde\bec\bcl\bla\bar\bre\be, t\bty\byp\bpe\bes\bse\bet\bt, e\bex\bxp\bpo\bor\brt\bt, r\bre\bea\bad\bdo\bon\bnl\bly\by, and l\blo\bo-\b-
- c\bca\bal\bl builtin commands (_\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn commands). When in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, these
- builtins may appear in a command after one or more instances of the
- c\bco\bom\bmm\bma\ban\bnd\bd builtin and retain these assignment statement properties.
-
- In the context where an assignment statement is assigning a value to a
+ is not used (see A\bAr\bri\bit\bth\bhm\bme\bet\bti\bic\bc E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn below). Word splitting and path-
+ name expansion are not performed. Assignment statements may also ap-
+ pear as arguments to the a\bal\bli\bia\bas\bs, d\bde\bec\bcl\bla\bar\bre\be, t\bty\byp\bpe\bes\bse\bet\bt, e\bex\bxp\bpo\bor\brt\bt, r\bre\bea\bad\bdo\bon\bnl\bly\by, and
+ l\blo\boc\bca\bal\bl builtin commands (_\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn commands). When in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be,
+ these builtins may appear in a command after one or more instances of
+ the c\bco\bom\bmm\bma\ban\bnd\bd builtin and retain these assignment statement properties.
+
+ 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. This includes arguments to
- builtin commands such as d\bde\bec\bcl\bla\bar\bre\be that accept assignment statements
- (_\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn commands). When += is applied to a variable for which the
+ or add to the variable's previous value. This includes arguments to
+ builtin commands such as d\bde\bec\bcl\bla\bar\bre\be that accept assignment statements
+ (_\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn commands). When += is applied to a variable for which the
i\bin\bnt\bte\beg\bge\ber\br attribute has been set, _\bv_\ba_\bl_\bu_\be is evaluated as an arithmetic ex-
pression and added to the variable's current value, which is also eval-
- uated. When += is applied to an array variable using compound assign-
- ment (see A\bAr\brr\bra\bay\bys\bs 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 arrays) or
- added as additional key-value pairs in an associative array. When ap-
- plied to a string-valued variable, _\bv_\ba_\bl_\bu_\be is expanded and appended to
+ uated. When += is applied to an array variable using compound assign-
+ ment (see A\bAr\brr\bra\bay\bys\bs 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 arrays) or
+ added as additional key-value pairs in an associative array. When ap-
+ plied to a string-valued variable, _\bv_\ba_\bl_\bu_\be is expanded and appended to
the variable's value.
A variable can be assigned the _\bn_\ba_\bm_\be_\br_\be_\bf attribute using the -\b-n\bn option to
- the d\bde\bec\bcl\bla\bar\bre\be or l\blo\boc\bca\bal\bl builtin commands (see the descriptions of d\bde\bec\bcl\bla\bar\bre\be
- and l\blo\boc\bca\bal\bl below) to create a _\bn_\ba_\bm_\be_\br_\be_\bf, or a reference to another vari-
- able. This allows variables to be manipulated indirectly. Whenever the
- nameref variable is referenced, assigned to, unset, or has its at-
- tributes modified (other than using or changing the _\bn_\ba_\bm_\be_\br_\be_\bf attribute
- itself), the operation is actually performed on the variable specified
- by the nameref variable's value. A nameref is commonly used within
+ the d\bde\bec\bcl\bla\bar\bre\be or l\blo\boc\bca\bal\bl builtin commands (see the descriptions of d\bde\bec\bcl\bla\bar\bre\be
+ and l\blo\boc\bca\bal\bl below) to create a _\bn_\ba_\bm_\be_\br_\be_\bf, or a reference to another vari-
+ able. This allows variables to be manipulated indirectly. Whenever
+ the nameref variable is referenced, assigned to, unset, or has its at-
+ tributes modified (other than using or changing the _\bn_\ba_\bm_\be_\br_\be_\bf attribute
+ itself), the operation is actually performed on the variable specified
+ by the nameref variable's value. A nameref is commonly used within
shell functions to refer to a variable whose name is passed as an argu-
- ment to the function. For instance, if a variable name is passed to a
+ ment to the function. For instance, if a variable name is passed to a
shell function as its first argument, running
declare -n ref=$1
- inside the function creates a nameref variable r\bre\bef\bf whose value is the
- variable name passed as the first argument. References and assignments
- to r\bre\bef\bf, and changes to its attributes, are treated as references, as-
- signments, and attribute modifications to the variable whose name was
- passed as $\b$1\b1. If the control variable in a f\bfo\bor\br loop has the nameref at-
- tribute, the list of words can be a list of shell variables, and a name
- reference will be established for each word in the list, in turn, when
- the loop is executed. Array variables cannot be given the n\bna\bam\bme\ber\bre\bef\bf at-
- tribute. However, nameref variables can reference array variables and
- subscripted array variables. Namerefs can be unset using the -\b-n\bn option
- to the u\bun\bns\bse\bet\bt builtin. Otherwise, if u\bun\bns\bse\bet\bt is executed with the name of
- a nameref variable as an argument, the variable referenced by the
- nameref variable will be unset.
+ inside the function creates a nameref variable r\bre\bef\bf whose value is the
+ variable name passed as the first argument. References and assignments
+ to r\bre\bef\bf, and changes to its attributes, are treated as references, as-
+ signments, and attribute modifications to the variable whose name was
+ passed as $\b$1\b1. If the control variable in a f\bfo\bor\br loop has the nameref
+ attribute, the list of words can be a list of shell variables, and a
+ name reference will be established for each word in the list, in turn,
+ when the loop is executed. Array variables cannot be given the n\bna\bam\bme\ber\bre\bef\bf
+ attribute. However, nameref variables can reference array variables
+ and subscripted array variables. Namerefs can be unset using the -\b-n\bn
+ option to the u\bun\bns\bse\bet\bt builtin. Otherwise, if u\bun\bns\bse\bet\bt is executed with the
+ name of a nameref variable as an argument, the variable referenced by
+ the nameref variable will be unset.
P\bPo\bos\bsi\bit\bti\bio\bon\bna\bal\bl P\bPa\bar\bra\bam\bme\bet\bte\ber\brs\bs
- A _\bp_\bo_\bs_\bi_\bt_\bi_\bo_\bn_\ba_\bl _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br 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 s\bse\bet\bt builtin command. Positional parameters may not be assigned to
- with assignment statements. The positional parameters are temporarily
+ A _\bp_\bo_\bs_\bi_\bt_\bi_\bo_\bn_\ba_\bl _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br 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 s\bse\bet\bt 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 F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS 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 E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN below).
S\bSp\bpe\bec\bci\bia\bal\bl P\bPa\bar\bra\bam\bme\bet\bte\ber\brs\bs
- 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.
- *\b* Expands to the positional parameters, starting from one. When
- the expansion is not within double quotes, each positional pa-
- rameter expands to a separate word. In contexts where it is per-
- formed, those words are subject to further word splitting and
- pathname expansion. When the expansion occurs within double
- quotes, it expands to a single word with the value of each pa-
- rameter separated by the first character of the I\bIF\bFS\bS special
- variable. That is, "$\b$*\b*" is equivalent to "$\b$1\b1_\bc$\b$2\b2_\bc.\b..\b..\b.", where _\bc is
- the first character of the value of the I\bIF\bFS\bS variable. If I\bIF\bFS\bS is
- unset, the parameters are separated by spaces. If I\bIF\bFS\bS is null,
- the parameters are joined without intervening separators.
- @\b@ Expands to the positional parameters, starting from one. In con-
- texts where word splitting is performed, this expands each posi-
- tional parameter to a separate word; if not within double
- quotes, these words are subject to word splitting. In contexts
- where word splitting is not performed, this expands to a single
- word with each positional parameter separated by a space. When
- the expansion occurs within double quotes, each parameter ex-
- pands to a separate word. That is, "$\b$@\b@" is equivalent to "$\b$1\b1"
- "$\b$2\b2" ... If the double-quoted expansion occurs within a word,
- the expansion of the first parameter is joined with the begin-
- ning part of the original word, and the expansion of the last
- parameter is joined with the last part of the original word.
- When there are no positional parameters, "$\b$@\b@" and $\b$@\b@ expand to
+ *\b* Expands to the positional parameters, starting from one. When
+ the expansion is not within double quotes, each positional pa-
+ rameter expands to a separate word. In contexts where it is
+ performed, those words are subject to further word splitting and
+ pathname expansion. When the expansion occurs within double
+ quotes, it expands to a single word with the value of each pa-
+ rameter separated by the first character of the I\bIF\bFS\bS special
+ variable. That is, "$\b$*\b*" is equivalent to "$\b$1\b1_\bc$\b$2\b2_\bc.\b..\b..\b.", where _\bc
+ is the first character of the value of the I\bIF\bFS\bS variable. If I\bIF\bFS\bS
+ is unset, the parameters are separated by spaces. If I\bIF\bFS\bS is
+ null, the parameters are joined without intervening separators.
+ @\b@ Expands to the positional parameters, starting from one. In
+ contexts where word splitting is performed, this expands each
+ positional parameter to a separate word; if not within double
+ quotes, these words are subject to word splitting. In contexts
+ where word splitting is not performed, this expands to a single
+ word with each positional parameter separated by a space. When
+ the expansion occurs within double quotes, each parameter ex-
+ pands to a separate word. That is, "$\b$@\b@" is equivalent to "$\b$1\b1"
+ "$\b$2\b2" ... If the double-quoted expansion occurs within a word,
+ the expansion of the first parameter is joined with the begin-
+ ning part of the original word, and the expansion of the last
+ parameter is joined with the last part of the original word.
+ When there are no positional parameters, "$\b$@\b@" and $\b$@\b@ expand to
nothing (i.e., they are removed).
#\b# Expands to the number of positional parameters in decimal.
- ?\b? Expands to the exit status of the most recently executed fore-
+ ?\b? Expands to the exit status of the most recently executed fore-
ground pipeline.
- -\b- Expands to the current option flags as specified upon invoca-
- tion, by the s\bse\bet\bt builtin command, or those set by the shell it-
+ -\b- Expands to the current option flags as specified upon invoca-
+ tion, by the s\bse\bet\bt builtin command, or those set by the shell it-
self (such as the -\b-i\bi option).
- $\b$ Expands to the process ID of the shell. In a subshell, it ex-
+ $\b$ Expands to the process ID of the shell. In a subshell, it ex-
pands to the process ID of the current shell, not the subshell.
- !\b! Expands to the process ID of the job most recently placed into
- the background, whether executed as an asynchronous command or
+ !\b! Expands to the process ID of the job most recently placed into
+ the background, whether executed as an asynchronous command or
using the b\bbg\bg builtin (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL below).
- 0\b0 Expands to the name of the shell or shell script. This is set at
- shell initialization. If b\bba\bas\bsh\bh is invoked with a file of com-
- mands, $\b$0\b0 is set to the name of that file. If b\bba\bas\bsh\bh is started
- with the -\b-c\bc option, then $\b$0\b0 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 b\bba\bas\bsh\bh, as given by argument
+ 0\b0 Expands to the name of the shell or shell script. This is set
+ at shell initialization. If b\bba\bas\bsh\bh is invoked with a file of com-
+ mands, $\b$0\b0 is set to the name of that file. If b\bba\bas\bsh\bh is started
+ with the -\b-c\bc option, then $\b$0\b0 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 b\bba\bas\bsh\bh, as given by argument
zero.
S\bSh\bhe\bel\bll\bl V\bVa\bar\bri\bia\bab\bbl\ble\bes\bs
The following variables are set by the shell:
- _\b_ At shell startup, set to the pathname used to invoke the shell
- or shell script being executed as passed in the environment or
- argument list. Subsequently, expands to the last argument to the
- previous simple command executed in the foreground, after expan-
- sion. Also set to the full pathname used to invoke each command
- executed and placed in the environment exported to that command.
- When checking mail, this parameter holds the name of the mail
- file currently being checked.
- B\bBA\bAS\bSH\bH Expands to the full filename used to invoke this instance of
+ _\b_ At shell startup, set to the pathname used to invoke the shell
+ or shell script being executed as passed in the environment or
+ argument list. Subsequently, expands to the last argument to
+ the previous simple command executed in the foreground, after
+ expansion. Also set to the full pathname used to invoke each
+ command executed and placed in the environment exported to that
+ command. When checking mail, this parameter holds the name of
+ the mail file currently being checked.
+ B\bBA\bAS\bSH\bH Expands to the full filename used to invoke this instance of
b\bba\bas\bsh\bh.
B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS
- A colon-separated list of enabled shell options. Each word in
- the list is a valid argument for the -\b-s\bs option to the s\bsh\bho\bop\bpt\bt
- builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). The options
- appearing in B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS are those reported as _\bo_\bn by s\bsh\bho\bop\bpt\bt. If this
- variable is in the environment when b\bba\bas\bsh\bh starts up, each shell
- option in the list will be enabled before reading any startup
- files. This variable is read-only.
+ A colon-separated list of enabled shell options. Each word in
+ the list is a valid argument for the -\b-s\bs option to the s\bsh\bho\bop\bpt\bt
+ builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). The options
+ appearing in B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS are those reported as _\bo_\bn by s\bsh\bho\bop\bpt\bt. If
+ this variable is in the environment when b\bba\bas\bsh\bh starts up, each
+ shell option in the list will be enabled before reading any
+ startup files. This variable is read-only.
B\bBA\bAS\bSH\bHP\bPI\bID\bD
- Expands to the process ID of the current b\bba\bas\bsh\bh process. This dif-
- fers from $\b$$\b$ under certain circumstances, such as subshells that
- do not require b\bba\bas\bsh\bh to be re-initialized. Assignments to B\bBA\bAS\bSH\bHP\bPI\bID\bD
- have no effect. If B\bBA\bAS\bSH\bHP\bPI\bID\bD is unset, it loses its special prop-
- erties, even if it is subsequently reset.
+ Expands to the process ID of the current b\bba\bas\bsh\bh process. This
+ differs from $\b$$\b$ under certain circumstances, such as subshells
+ that do not require b\bba\bas\bsh\bh to be re-initialized. Assignments to
+ B\bBA\bAS\bSH\bHP\bPI\bID\bD have no effect. If B\bBA\bAS\bSH\bHP\bPI\bID\bD is unset, it loses its spe-
+ cial properties, even if it is subsequently reset.
B\bBA\bAS\bSH\bH_\b_A\bAL\bLI\bIA\bAS\bSE\bES\bS
- An associative array variable whose members correspond to the
- internal list of aliases as maintained by the a\bal\bli\bia\bas\bs builtin. El-
- ements added to this array appear in the alias list; however,
- unsetting array elements currently does not cause aliases to be
- removed from the alias list. If B\bBA\bAS\bSH\bH_\b_A\bAL\bLI\bIA\bAS\bSE\bES\bS is unset, it loses
+ An associative array variable whose members correspond to the
+ internal list of aliases as maintained by the a\bal\bli\bia\bas\bs builtin.
+ Elements added to this array appear in the alias list; however,
+ unsetting array elements currently does not cause aliases to be
+ removed from the alias list. If B\bBA\bAS\bSH\bH_\b_A\bAL\bLI\bIA\bAS\bSE\bES\bS is unset, it loses
its special properties, even if it is subsequently reset.
B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC
- An array variable whose values are the number of parameters in
- each frame of the current b\bba\bas\bsh\bh execution call stack. The number
- of parameters to the current subroutine (shell function or
- script executed with .\b. or s\bso\bou\bur\brc\bce\be) is at the top of the stack.
- When a subroutine is executed, the number of parameters passed
- is pushed onto B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC. The shell sets B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC only when in
+ An array variable whose values are the number of parameters in
+ each frame of the current b\bba\bas\bsh\bh execution call stack. The number
+ of parameters to the current subroutine (shell function or
+ script executed with .\b. or s\bso\bou\bur\brc\bce\be) is at the top of the stack.
+ When a subroutine is executed, the number of parameters passed
+ is pushed onto B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC. The shell sets B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC only when in
extended debugging mode (see the description of the e\bex\bxt\btd\bde\beb\bbu\bug\bg op-
- tion to the s\bsh\bho\bop\bpt\bt builtin below). Setting e\bex\bxt\btd\bde\beb\bbu\bug\bg after the
+ tion to the s\bsh\bho\bop\bpt\bt builtin below). Setting e\bex\bxt\btd\bde\beb\bbu\bug\bg after the
shell has started to execute a script, or referencing this vari-
- able when e\bex\bxt\btd\bde\beb\bbu\bug\bg is not set, may result in inconsistent val-
- ues. Assignments to B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC have no effect, and it may not be
+ able when e\bex\bxt\btd\bde\beb\bbu\bug\bg is not set, may result in inconsistent val-
+ ues. Assignments to B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC have no effect, and it may not be
unset.
B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV
- An array variable containing all of the parameters in the cur-
- rent b\bba\bas\bsh\bh execution call stack. The final parameter of the last
- subroutine call is at the top of the stack; the first parameter
- of the initial call is at the bottom. When a subroutine is exe-
- cuted, the parameters supplied are pushed onto B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV. The
- shell sets B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV only when in extended debugging mode (see
- the description of the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the s\bsh\bho\bop\bpt\bt builtin be-
- low). Setting e\bex\bxt\btd\bde\beb\bbu\bug\bg after the shell has started to execute a
- script, or referencing this variable when e\bex\bxt\btd\bde\beb\bbu\bug\bg is not set,
- may result in inconsistent values. Assignments to B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV have
- no effect, and it may not be unset.
+ An array variable containing all of the parameters in the cur-
+ rent b\bba\bas\bsh\bh execution call stack. The final parameter of the last
+ subroutine call is at the top of the stack; the first parameter
+ of the initial call is at the bottom. When a subroutine is exe-
+ cuted, the parameters supplied are pushed onto B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV. The
+ shell sets B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV only when in extended debugging mode (see
+ the description of the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the s\bsh\bho\bop\bpt\bt builtin be-
+ low). Setting e\bex\bxt\btd\bde\beb\bbu\bug\bg after the shell has started to execute a
+ script, or referencing this variable when e\bex\bxt\btd\bde\beb\bbu\bug\bg is not set,
+ may result in inconsistent values. Assignments to B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV
+ have no effect, and it may not be unset.
B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0
- When referenced, this variable expands to the name of the shell
+ When referenced, this variable expands to the name of the shell
or shell script (identical to $\b$0\b0; see the description of special
- parameter 0 above). Assignment to B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0 causes the value
- assigned to also be assigned to $\b$0\b0. If B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0 is unset, it
+ parameter 0 above). Assignment to B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0 causes the value
+ assigned to also be assigned to $\b$0\b0. If B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0 is unset, it
loses its special properties, even if it is subsequently reset.
B\bBA\bAS\bSH\bH_\b_C\bCM\bMD\bDS\bS
- An associative array variable whose members correspond to the
- internal hash table of commands as maintained by the h\bha\bas\bsh\bh
+ An associative array variable whose members correspond to the
+ internal hash table of commands as maintained by the h\bha\bas\bsh\bh
builtin. Elements added to this array appear in the hash table;
- however, unsetting array elements currently does not cause com-
- mand names to be removed from the hash table. If B\bBA\bAS\bSH\bH_\b_C\bCM\bMD\bDS\bS is
- unset, it loses its special properties, even if it is subse-
+ however, unsetting array elements currently does not cause com-
+ mand names to be removed from the hash table. If B\bBA\bAS\bSH\bH_\b_C\bCM\bMD\bDS\bS is
+ unset, it loses its special properties, even if it is subse-
quently reset.
B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD
- 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
- trap. If B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD is unset, it loses its special properties,
- even if it is subsequently reset.
+ in which case it is the command executing at the time of the
+ trap. If B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD is unset, it loses its special proper-
+ ties, even if it is subsequently reset.
B\bBA\bAS\bSH\bH_\b_E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN_\b_S\bST\bTR\bRI\bIN\bNG\bG
The command argument to the -\b-c\bc invocation option.
B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO
- An array variable whose members are the line numbers in source
- files where each corresponding member of F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE was invoked.
+ An array variable whose members are the line numbers in source
+ files where each corresponding member of F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE was invoked.
$\b${\b{B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO[\b[_\b$_\bi]\b]}\b} is the line number in the source file
($\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi_\b+_\b1]\b]}\b}) where $\b${\b{F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE[\b[_\b$_\bi]\b]}\b} was called (or
- $\b${\b{B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO[\b[_\b$_\bi_\b-_\b1]\b]}\b} if referenced within another shell func-
- tion). Use L\bLI\bIN\bNE\bEN\bNO\bO to obtain the current line number. Assignments
- to B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO have no effect, and it may not be unset.
+ $\b${\b{B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO[\b[_\b$_\bi_\b-_\b1]\b]}\b} if referenced within another shell func-
+ tion). Use L\bLI\bIN\bNE\bEN\bNO\bO to obtain the current line number. Assign-
+ ments to B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO have no effect, and it may not be unset.
B\bBA\bAS\bSH\bH_\b_L\bLO\bOA\bAD\bDA\bAB\bBL\bLE\bES\bS_\b_P\bPA\bAT\bTH\bH
- A colon-separated list of directories in which the shell looks
- for dynamically loadable builtins specified by the e\ben\bna\bab\bbl\ble\be com-
+ A colon-separated list of directories in which the shell looks
+ for dynamically loadable builtins specified by the e\ben\bna\bab\bbl\ble\be com-
mand.
B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH
- An array variable whose members are assigned by the =\b=~\b~ binary
- operator to the [\b[[\b[ conditional command. The element with index 0
- is the portion of the string matching the entire regular expres-
- sion. The element with index _\bn is the portion of the string
+ An array variable whose members are assigned by the =\b=~\b~ binary
+ operator to the [\b[[\b[ conditional command. The element with index
+ 0 is the portion of the string matching the entire regular ex-
+ pression. The element with index _\bn is the portion of the string
matching the _\bnth parenthesized subexpression.
B\bBA\bAS\bSH\bH_\b_M\bMO\bON\bNO\bOS\bSE\bEC\bCO\bON\bND\bDS\bS
- Each time this variable is referenced, it expands to the value
- returned by the system's monotonic clock, if one is available.
- If there is no monotonic clock, this is equivalent to E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bC-\b-
- O\bON\bND\bDS\bS. If B\bBA\bAS\bSH\bH_\b_M\bMO\bON\bNO\bOS\bSE\bEC\bCO\bON\bND\bDS\bS is unset, it loses its special proper-
- ties, even if it is subsequently reset.
+ Each time this variable is referenced, it expands to the value
+ returned by the system's monotonic clock, if one is available.
+ If there is no monotonic clock, this is equivalent to E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bC-\b-
+ O\bON\bND\bDS\bS. If B\bBA\bAS\bSH\bH_\b_M\bMO\bON\bNO\bOS\bSE\bEC\bCO\bON\bND\bDS\bS is unset, it loses its special prop-
+ erties, even if it is subsequently reset.
B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE
- An array variable whose members are the source filenames where
- the corresponding shell function names in the F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE array
- variable are defined. The shell function $\b${\b{F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE[\b[_\b$_\bi]\b]}\b} is de-
- fined in the file $\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi]\b]}\b} and called from
- $\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi_\b+_\b1]\b]}\b}. Assignments to B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE have no effect,
- and it may not be unset.
+ An array variable whose members are the source filenames where
+ the corresponding shell function names in the F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE array
+ variable are defined. The shell function $\b${\b{F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE[\b[_\b$_\bi]\b]}\b} is de-
+ fined in the file $\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi]\b]}\b} and called from
+ $\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi_\b+_\b1]\b]}\b}. Assignments to B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE have no ef-
+ fect, and it may not be unset.
B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL
- Incremented by one within each subshell or subshell environment
- when the shell begins executing in that environment. The initial
- value is 0. If B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL is unset, it loses its special
- properties, even if it is subsequently reset.
+ Incremented by one within each subshell or subshell environment
+ when the shell begins executing in that environment. The ini-
+ tial value is 0. If B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL is unset, it loses its spe-
+ cial properties, even if it is subsequently reset.
B\bBA\bAS\bSH\bH_\b_T\bTR\bRA\bAP\bPS\bSI\bIG\bG
- Set to the signal number corresponding to the trap action being
- executed during its execution. See the description of t\btr\bra\bap\bp under
- S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below for information about signal num-
- bers and trap execution.
+ Set to the signal number corresponding to the trap action being
+ executed during its execution. See the description of t\btr\bra\bap\bp un-
+ der S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below for information about signal
+ numbers and trap execution.
B\bBA\bAS\bSH\bH_\b_V\bVE\bER\bRS\bSI\bIN\bNF\bFO\bO
A readonly array variable whose members hold version information
- for this instance of b\bba\bas\bsh\bh. The values assigned to the array mem-
- bers are as follows:
+ for this instance of b\bba\bas\bsh\bh. The values assigned to the array
+ members are as follows:
B\bBA\bAS\bSH\bH_\b_V\bVE\bER\bRS\bSI\bIN\bNF\bFO\bO[\b[0]\b] The major version number (the _\br_\be_\bl_\be_\ba_\bs_\be).
B\bBA\bAS\bSH\bH_\b_V\bVE\bER\bRS\bSI\bIN\bNF\bFO\bO[\b[1]\b] The minor version number (the _\bv_\be_\br_\bs_\bi_\bo_\bn).
B\bBA\bAS\bSH\bH_\b_V\bVE\bER\bRS\bSI\bIN\bNF\bFO\bO[\b[2]\b] The patch level.
B\bBA\bAS\bSH\bH_\b_V\bVE\bER\bRS\bSI\bIN\bNF\bFO\bO[\b[4]\b] The release status (e.g., _\bb_\be_\bt_\ba_\b1).
B\bBA\bAS\bSH\bH_\b_V\bVE\bER\bRS\bSI\bIN\bNF\bFO\bO[\b[5]\b] The value of M\bMA\bAC\bCH\bHT\bTY\bYP\bPE\bE.
B\bBA\bAS\bSH\bH_\b_V\bVE\bER\bRS\bSI\bIO\bON\bN
- Expands to a string describing the version of this instance of
+ Expands to a string describing the version of this instance of
b\bba\bas\bsh\bh.
C\bCO\bOM\bMP\bP_\b_C\bCW\bWO\bOR\bRD\bD
- An index into $\b${\b{C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDS\bS}\b} of the word containing the current
- cursor position. This variable is available only in shell func-
- tions invoked by the programmable completion facilities (see
+ An index into $\b${\b{C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDS\bS}\b} of the word containing the current
+ cursor position. This variable is available only in shell func-
+ tions invoked by the programmable completion facilities (see
P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below).
C\bCO\bOM\bMP\bP_\b_K\bKE\bEY\bY
The key (or final key of a key sequence) used to invoke the cur-
rent completion function.
C\bCO\bOM\bMP\bP_\b_L\bLI\bIN\bNE\bE
- The current command line. This variable is available only in
- shell functions and external commands invoked by the program-
+ The current command line. This variable is available only in
+ shell functions and external commands invoked by the program-
mable completion facilities (see P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below).
C\bCO\bOM\bMP\bP_\b_P\bPO\bOI\bIN\bNT\bT
- 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 $\b${\b{#\b#C\bCO\bOM\bMP\bP_\b_L\bLI\bIN\bNE\bE}\b}. This variable is available only in shell
- functions and external commands invoked by the programmable com-
- pletion facilities (see P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below).
+ equal to $\b${\b{#\b#C\bCO\bOM\bMP\bP_\b_L\bLI\bIN\bNE\bE}\b}. This variable is available only in
+ shell functions and external commands invoked by the program-
+ mable completion facilities (see P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below).
C\bCO\bOM\bMP\bP_\b_T\bTY\bYP\bPE\bE
- Set to an integer value corresponding to the type of completion
- attempted that caused a completion function to be called: _\bT_\bA_\bB,
- for normal completion, _\b?, for listing completions after succes-
- sive tabs, _\b!, for listing alternatives on partial word comple-
- tion, _\b@, to list completions if the word is not unmodified, or
- _\b%, for menu completion. This variable is available only in shell
- functions and external commands invoked by the programmable com-
- pletion facilities (see P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below).
+ Set to an integer value corresponding to the type of completion
+ attempted that caused a completion function to be called: _\bT_\bA_\bB,
+ for normal completion, _\b?, for listing completions after succes-
+ sive tabs, _\b!, for listing alternatives on partial word comple-
+ tion, _\b@, to list completions if the word is not unmodified, or
+ _\b%, for menu completion. This variable is available only in
+ shell functions and external commands invoked by the program-
+ mable completion facilities (see P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below).
C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS
- The set of characters that the r\bre\bea\bad\bdl\bli\bin\bne\be library treats as word
- separators when performing word completion. If C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS
- is unset, it loses its special properties, even if it is subse-
+ The set of characters that the r\bre\bea\bad\bdl\bli\bin\bne\be library treats as word
+ separators when performing word completion. If C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS
+ is unset, it loses its special properties, even if it is subse-
quently reset.
C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDS\bS
- An array variable (see A\bAr\brr\bra\bay\bys\bs below) consisting of the individ-
- ual words in the current command line. The line is split into
- words as r\bre\bea\bad\bdl\bli\bin\bne\be would split it, using C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS as de-
- scribed above. This variable is available only in shell func-
- tions invoked by the programmable completion facilities (see
+ An array variable (see A\bAr\brr\bra\bay\bys\bs below) consisting of the individ-
+ ual words in the current command line. The line is split into
+ words as r\bre\bea\bad\bdl\bli\bin\bne\be would split it, using C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS as de-
+ scribed above. This variable is available only in shell func-
+ tions invoked by the programmable completion facilities (see
P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below).
- C\bCO\bOP\bPR\bRO\bOC\bC An array variable (see A\bAr\brr\bra\bay\bys\bs below) created to hold the file
- descriptors for output from and input to an unnamed coprocess
+ C\bCO\bOP\bPR\bRO\bOC\bC An array variable (see A\bAr\brr\bra\bay\bys\bs below) created to hold the file
+ descriptors for output from and input to an unnamed coprocess
(see C\bCo\bop\bpr\bro\boc\bce\bes\bss\bse\bes\bs above).
D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK
An array variable (see A\bAr\brr\bra\bay\bys\bs below) containing the current con-
- tents of the directory stack. Directories appear in the stack in
- the order they are displayed by the d\bdi\bir\brs\bs builtin. Assigning to
- members of this array variable may be used to modify directories
- already in the stack, but the p\bpu\bus\bsh\bhd\bd and p\bpo\bop\bpd\bd builtins must be
- used to add and remove directories. Assignment to this variable
- will not change the current directory. If D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK is unset, it
- loses its special properties, even if it is subsequently reset.
+ tents of the directory stack. Directories appear in the stack
+ in the order they are displayed by the d\bdi\bir\brs\bs builtin. Assigning
+ to members of this array variable may be used to modify directo-
+ ries already in the stack, but the p\bpu\bus\bsh\bhd\bd and p\bpo\bop\bpd\bd builtins must
+ be used to add and remove directories. Assignment to this vari-
+ able will not change the current directory. If D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK is un-
+ set, it loses its special properties, even if it is subsequently
+ reset.
E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE
Each time this parameter is referenced, it expands to the number
of seconds since the Unix Epoch (see _\bt_\bi_\bm_\be(3)) as a floating
- point value with micro-second granularity. Assignments to
- E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE are ignored. If E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE is unset, it loses
+ point value with micro-second granularity. Assignments to
+ E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE are ignored. If E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE is unset, it loses
its special properties, even if it is subsequently reset.
E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS
Each time this parameter is referenced, it expands to the number
- of seconds since the Unix Epoch (see _\bt_\bi_\bm_\be(3)). Assignments to
- E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS are ignored. If E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS is unset, it loses its
- special properties, even if it is subsequently reset.
+ of seconds since the Unix Epoch (see _\bt_\bi_\bm_\be(3)). Assignments to
+ E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS are ignored. If E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS is unset, it loses
+ its special properties, even if it is subsequently reset.
E\bEU\bUI\bID\bD Expands to the effective user ID of the current user, initial-
- ized at shell startup. This variable is readonly.
+ ized at shell startup. This variable is readonly.
F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE
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-
+ 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 F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE have no effect. If F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE is unset, it
- loses its special properties, even if it is subsequently reset.
-
- This variable can be used with B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO and B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE. Each
- element of F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE has corresponding elements in B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO
- and B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE to describe the call stack. For instance,
- $\b${\b{F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE[\b[_\b$_\bi]\b]}\b} was called from the file $\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi_\b+_\b1]\b]}\b} at
- line number $\b${\b{B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO[\b[_\b$_\bi]\b]}\b}. The c\bca\bal\bll\ble\ber\br builtin displays the
- current call stack using this information.
+ Assignments to F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE have no effect. If F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE is unset,
+ it loses its special properties, even if it is subsequently re-
+ set.
+
+ This variable can be used with B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO and B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE.
+ Each element of F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE has corresponding elements in
+ B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO and B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE to describe the call stack. For in-
+ stance, $\b${\b{F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE[\b[_\b$_\bi]\b]}\b} was called from the file
+ $\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi_\b+_\b1]\b]}\b} at line number $\b${\b{B\bBA\bAS\bSH\bH_\b_L\bLI\bIN\bNE\bEN\bNO\bO[\b[_\b$_\bi]\b]}\b}. The
+ c\bca\bal\bll\ble\ber\br builtin displays the current call stack using this infor-
+ mation.
G\bGR\bRO\bOU\bUP\bPS\bS An array variable containing the list of groups of which the
- current user is a member. Assignments to G\bGR\bRO\bOU\bUP\bPS\bS have no effect.
+ current user is a member. Assignments to G\bGR\bRO\bOU\bUP\bPS\bS have no effect.
If G\bGR\bRO\bOU\bUP\bPS\bS is unset, it loses its special properties, even if it
is subsequently reset.
H\bHI\bIS\bST\bTC\bCM\bMD\bD
The history number, or index in the history list, of the current
- command. Assignments to H\bHI\bIS\bST\bTC\bCM\bMD\bD are ignored. If H\bHI\bIS\bST\bTC\bCM\bMD\bD is un-
+ command. Assignments to H\bHI\bIS\bST\bTC\bCM\bMD\bD are ignored. If H\bHI\bIS\bST\bTC\bCM\bMD\bD is un-
set, it loses its special properties, even if it is subsequently
reset.
H\bHO\bOS\bST\bTN\bNA\bAM\bME\bE
Automatically set to the name of the current host.
H\bHO\bOS\bST\bTT\bTY\bYP\bPE\bE
Automatically set to a string that uniquely describes the type
- of machine on which b\bba\bas\bsh\bh is executing. The default is system-de-
- pendent.
+ of machine on which b\bba\bas\bsh\bh is executing. The default is system-
+ dependent.
L\bLI\bIN\bNE\bEN\bNO\bO 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
+ (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 L\bLI\bIN\bNE\bEN\bNO\bO is unset, it loses its special proper-
+ be meaningful. If L\bLI\bIN\bNE\bEN\bNO\bO is unset, it loses its special proper-
ties, even if it is subsequently reset.
M\bMA\bAC\bCH\bHT\bTY\bYP\bPE\bE
Automatically set to a string that fully describes the system
type on which b\bba\bas\bsh\bh is executing, in the standard GNU _\bc_\bp_\bu_\b-_\bc_\bo_\bm_\b-
- _\bp_\ba_\bn_\by_\b-_\bs_\by_\bs_\bt_\be_\bm format. The default is system-dependent.
+ _\bp_\ba_\bn_\by_\b-_\bs_\by_\bs_\bt_\be_\bm format. The default is system-dependent.
M\bMA\bAP\bPF\bFI\bIL\bLE\bE
An array variable (see A\bAr\brr\bra\bay\bys\bs below) created to hold the text
read by the m\bma\bap\bpf\bfi\bil\ble\be builtin when no variable name is supplied.
O\bOP\bPT\bTI\bIN\bND\bD The index of the next argument to be processed by the g\bge\bet\bto\bop\bpt\bts\bs
builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
O\bOS\bST\bTY\bYP\bPE\bE Automatically set to a string that describes the operating sys-
- tem on which b\bba\bas\bsh\bh is executing. The default is system-dependent.
+ tem on which b\bba\bas\bsh\bh is executing. The default is system-depen-
+ dent.
P\bPI\bIP\bPE\bES\bST\bTA\bAT\bTU\bUS\bS
- An array variable (see A\bAr\brr\bra\bay\bys\bs below) containing a list of exit
- status values from the processes in the most-recently-executed
+ An array variable (see A\bAr\brr\bra\bay\bys\bs 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).
- P\bPP\bPI\bID\bD The process ID of the shell's parent. This variable is readonly.
+ P\bPP\bPI\bID\bD The process ID of the shell's parent. This variable is read-
+ only.
P\bPW\bWD\bD The current working directory as set by the c\bcd\bd command.
R\bRA\bAN\bND\bDO\bOM\bM Each time this parameter is referenced, it expands to a random
- integer between 0 and 32767. Assigning a value to R\bRA\bAN\bND\bDO\bOM\bM ini-
+ integer between 0 and 32767. Assigning a value to R\bRA\bAN\bND\bDO\bOM\bM ini-
tializes (seeds) the sequence of random numbers. If R\bRA\bAN\bND\bDO\bOM\bM is
unset, it loses its special properties, even if it is subse-
quently reset.
no arguments are supplied.
S\bSE\bEC\bCO\bON\bND\bDS\bS
Each time this parameter is referenced, it expands to the number
- of seconds since shell invocation. If a value is assigned to
+ of seconds since shell invocation. If a value is assigned to
S\bSE\bEC\bCO\bON\bND\bDS\bS, the value returned upon subsequent references is the
number of seconds since the assignment plus the value assigned.
The number of seconds at shell invocation and the current time
- are always determined by querying the system clock. If S\bSE\bEC\bCO\bON\bND\bDS\bS
+ are always determined by querying the system clock. If S\bSE\bEC\bCO\bON\bND\bDS\bS
is unset, it loses its special properties, even if it is subse-
quently reset.
S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS
- A colon-separated list of enabled shell options. Each word in
+ A colon-separated list of enabled shell options. Each word in
the list is a valid argument for the -\b-o\bo option to the s\bse\bet\bt
- builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). The options
- appearing in S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS are those reported as _\bo_\bn by s\bse\bet\bt -\b-o\bo. If
+ builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). The options
+ appearing in S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS are those reported as _\bo_\bn by s\bse\bet\bt -\b-o\bo. If
this variable is in the environment when b\bba\bas\bsh\bh starts up, each
shell option in the list will be enabled before reading any
- startup files. This variable is read-only.
+ startup files. This variable is read-only.
S\bSH\bHL\bLV\bVL\bL Incremented by one each time an instance of b\bba\bas\bsh\bh is started.
S\bSR\bRA\bAN\bND\bDO\bOM\bM
This variable expands to a 32-bit pseudo-random number each time
systems that support /dev/urandom or _\ba_\br_\bc_\b4_\br_\ba_\bn_\bd_\bo_\bm, so each re-
turned number has no relationship to the numbers preceding it.
The random number generator cannot be seeded, so assignments to
- this variable have no effect. If S\bSR\bRA\bAN\bND\bDO\bOM\bM is unset, it loses its
+ this variable have no effect. If S\bSR\bRA\bAN\bND\bDO\bOM\bM is unset, it loses its
special properties, even if it is subsequently reset.
U\bUI\bID\bD Expands to the user ID of the current user, initialized at shell
- startup. This variable is readonly.
+ startup. This variable is readonly.
- The following variables are used by the shell. In some cases, b\bba\bas\bsh\bh as-
+ The following variables are used by the shell. In some cases, b\bba\bas\bsh\bh as-
signs a default value to a variable; these cases are noted below.
B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT
- The value is used to set the shell's compatibility level. See
+ The value is used to set the shell's compatibility level. See
S\bSH\bHE\bEL\bLL\bL C\bCO\bOM\bMP\bPA\bAT\bTI\bIB\bBI\bIL\bLI\bIT\bTY\bY M\bMO\bOD\bDE\bE below for a description of the various
- compatibility levels and their effects. The value may be a deci-
- mal number (e.g., 4.2) or an integer (e.g., 42) corresponding to
- the desired compatibility level. If B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT is unset or set
- to the empty string, the compatibility level is set to the de-
- fault for the current version. If B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT is set to a value
- that is not one of the valid compatibility levels, the shell
- prints an error message and sets the compatibility level to the
- default for the current version. The valid values correspond to
- the compatibility levels described below under S\bSH\bHE\bEL\bLL\bL C\bCO\bOM\bMP\bPA\bAT\bTI\bIB\bBI\bIL\bL-\b-
- I\bIT\bTY\bY M\bMO\bOD\bDE\bE. For example, 4.2 and 42 are valid values that corre-
- spond to the c\bco\bom\bmp\bpa\bat\bt4\b42\b2 s\bsh\bho\bop\bpt\bt option and set the compatibility
- level to 42. The current version is also a valid value.
+ compatibility levels and their effects. The value may be a dec-
+ imal number (e.g., 4.2) or an integer (e.g., 42) corresponding
+ to the desired compatibility level. If B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT is unset or
+ set to the empty string, the compatibility level is set to the
+ default for the current version. If B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT is set to a
+ value that is not one of the valid compatibility levels, the
+ shell prints an error message and sets the compatibility level
+ to the default for the current version. The valid values corre-
+ spond to the compatibility levels described below under S\bSH\bHE\bEL\bLL\bL
+ C\bCO\bOM\bMP\bPA\bAT\bTI\bIB\bBI\bIL\bLI\bIT\bTY\bY M\bMO\bOD\bDE\bE. For example, 4.2 and 42 are valid values
+ that correspond to the c\bco\bom\bmp\bpa\bat\bt4\b42\b2 s\bsh\bho\bop\bpt\bt option and set the compat-
+ ibility level to 42. The current version is also a valid value.
B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV
If this parameter is set when b\bba\bas\bsh\bh is executing a shell script,
its value is interpreted as a filename containing commands to
- initialize the shell, as in _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc. The value of B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV is
+ initialize the shell, as in _\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc. The value of B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV is
subjected to parameter expansion, command substitution, and
arithmetic expansion before being interpreted as a filename.
P\bPA\bAT\bTH\bH is not used to search for the resultant filename.
B\bBA\bAS\bSH\bH_\b_X\bXT\bTR\bRA\bAC\bCE\bEF\bFD\bD
If set to an integer corresponding to a valid file descriptor,
b\bba\bas\bsh\bh will write the trace output generated when _\bs_\be_\bt _\b-_\bx is en-
- abled to that file descriptor. The file descriptor is closed
- when B\bBA\bAS\bSH\bH_\b_X\bXT\bTR\bRA\bAC\bCE\bEF\bFD\bD is unset or assigned a new value. Unsetting
+ abled to that file descriptor. The file descriptor is closed
+ when B\bBA\bAS\bSH\bH_\b_X\bXT\bTR\bRA\bAC\bCE\bEF\bFD\bD is unset or assigned a new value. Unsetting
B\bBA\bAS\bSH\bH_\b_X\bXT\bTR\bRA\bAC\bCE\bEF\bFD\bD or assigning it the empty string causes the trace
- output to be sent to the standard error. Note that setting
+ output to be sent to the standard error. Note that setting
B\bBA\bAS\bSH\bH_\b_X\bXT\bTR\bRA\bAC\bCE\bEF\bFD\bD to 2 (the standard error file descriptor) and then
unsetting it will result in the standard error being closed.
- C\bCD\bDP\bPA\bAT\bTH\bH The search path for the c\bcd\bd command. This is a colon-separated
+ C\bCD\bDP\bPA\bAT\bTH\bH The search path for the c\bcd\bd command. This is a colon-separated
list of directories in which the shell looks for destination di-
- rectories specified by the c\bcd\bd command. A sample value is
+ rectories specified by the c\bcd\bd command. A sample value is
".:~:/usr".
C\bCH\bHI\bIL\bLD\bD_\b_M\bMA\bAX\bX
Set the number of exited child status values for the shell to
- remember. B\bBa\bas\bsh\bh will not allow this value to be decreased below a
- POSIX-mandated minimum, and there is a maximum value (currently
- 8192) that this may not exceed. The minimum value is system-de-
- pendent.
+ remember. B\bBa\bas\bsh\bh will not allow this value to be decreased below
+ a POSIX-mandated minimum, and there is a maximum value (cur-
+ rently 8192) that this may not exceed. The minimum value is
+ system-dependent.
C\bCO\bOL\bLU\bUM\bMN\bNS\bS
Used by the s\bse\bel\ble\bec\bct\bt compound command to determine the terminal
- width when printing selection lists. Automatically set if the
+ width when printing selection lists. Automatically set if the
c\bch\bhe\bec\bck\bkw\bwi\bin\bns\bsi\biz\bze\be option is enabled or in an interactive shell upon
receipt of a S\bSI\bIG\bGW\bWI\bIN\bNC\bCH\bH.
C\bCO\bOM\bMP\bPR\bRE\bEP\bPL\bLY\bY
An array variable from which b\bba\bas\bsh\bh reads the possible completions
generated by a shell function invoked by the programmable com-
- pletion facility (see P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below). Each array
- element contains one possible completion.
+ pletion facility (see P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn below). Each ar-
+ ray element contains one possible completion.
E\bEM\bMA\bAC\bCS\bS If b\bba\bas\bsh\bh 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.
E\bEX\bXE\bEC\bCI\bIG\bGN\bNO\bOR\bRE\bE
A colon-separated list of shell patterns (see P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg)
defining the list of filenames to be ignored by command search
- using P\bPA\bAT\bTH\bH. Files whose full pathnames match one of these pat-
+ using P\bPA\bAT\bTH\bH. Files whose full pathnames match one of these pat-
terns are not considered executable files for the purposes of
- completion and command execution via P\bPA\bAT\bTH\bH lookup. This does not
- affect the behavior of the [\b[, t\bte\bes\bst\bt, and [\b[[\b[ commands. Full path-
+ completion and command execution via P\bPA\bAT\bTH\bH lookup. This does not
+ affect the behavior of the [\b[, t\bte\bes\bst\bt, and [\b[[\b[ commands. Full path-
names in the command hash table are not subject to E\bEX\bXE\bEC\bCI\bIG\bGN\bNO\bOR\bRE\bE.
Use this variable to ignore shared library files that have the
- executable bit set, but are not executable files. The pattern
+ executable bit set, but are not executable files. The pattern
matching honors the setting of the e\bex\bxt\btg\bgl\blo\bob\bb shell option.
F\bFC\bCE\bED\bDI\bIT\bT The default editor for the f\bfc\bc builtin command.
F\bFI\bIG\bGN\bNO\bOR\bRE\bE
A colon-separated list of suffixes to ignore when performing
- filename completion (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE below). A filename whose suf-
+ filename completion (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE below). A filename whose suf-
fix matches one of the entries in F\bFI\bIG\bGN\bNO\bOR\bRE\bE is excluded from the
- list of matched filenames. A sample value is ".o:~".
+ list of matched filenames. A sample value is ".o:~".
F\bFU\bUN\bNC\bCN\bNE\bES\bST\bT
If set to a numeric value greater than 0, defines a maximum
function nesting level. Function invocations that exceed this
matched by a pathname expansion pattern also matches one of the
patterns in G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE, it is removed from the list of matches.
G\bGL\bLO\bOB\bBS\bSO\bOR\bRT\bT
- Control how the results of pathname expansion are sorted. The
+ Control how the results of pathname expansion are sorted. The
value of this variable specifies the sort criteria and sort or-
- der for the results of pathname expansion. If this variable is
+ der for the results of pathname expansion. If this variable is
unset or set to the null string, pathname expansion uses the
- historial behavior of sorting by name. If set, a valid value be-
- gins with an optional _\b+, which is ignored, or _\b-, which reverses
- the sort order from ascending to descending, followed by a sort
- specifier. The valid sort specifiers are _\bn_\ba_\bm_\be, _\bs_\bi_\bz_\be, _\bm_\bt_\bi_\bm_\be,
- _\ba_\bt_\bi_\bm_\be, _\bc_\bt_\bi_\bm_\be, and _\bb_\bl_\bo_\bc_\bk_\bs, which sort the files on name, file
- size, modification time, access time, inode change time, and
- number of blocks, respectively. For example, a value of _\b-_\bm_\bt_\bi_\bm_\be
- sorts the results in descending order by modification time (new-
- est first). A sort specifier of _\bn_\bo_\bs_\bo_\br_\bt disables sorting com-
- pletely; the results are returned in the order they are read
- from the file system,. If the sort specifier is missing, it de-
- faults to _\bn_\ba_\bm_\be, so a value of _\b+ is equivalent to the null
- string, and a value of _\b- sorts by name in descending order. Any
+ historial behavior of sorting by name. If set, a valid value
+ begins with an optional _\b+, which is ignored, or _\b-, which re-
+ verses the sort order from ascending to descending, followed by
+ a sort specifier. The valid sort specifiers are _\bn_\ba_\bm_\be, _\bs_\bi_\bz_\be,
+ _\bm_\bt_\bi_\bm_\be, _\ba_\bt_\bi_\bm_\be, _\bc_\bt_\bi_\bm_\be, and _\bb_\bl_\bo_\bc_\bk_\bs, which sort the files on name,
+ file size, modification time, access time, inode change time,
+ and number of blocks, respectively. For example, a value of
+ _\b-_\bm_\bt_\bi_\bm_\be sorts the results in descending order by modification
+ time (newest first). A sort specifier of _\bn_\bo_\bs_\bo_\br_\bt disables sort-
+ ing completely; the results are returned in the order they are
+ read from the file system,. If the sort specifier is missing,
+ it defaults to _\bn_\ba_\bm_\be, so a value of _\b+ is equivalent to the null
+ string, and a value of _\b- sorts by name in descending order. Any
invalid value restores the historical sorting behavior.
H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL
A colon-separated list of values controlling how commands are
- saved on the history list. If the list of values includes _\bi_\bg_\b-
+ saved on the history list. If the list of values includes _\bi_\bg_\b-
_\bn_\bo_\br_\be_\bs_\bp_\ba_\bc_\be, lines which begin with a s\bsp\bpa\bac\bce\be character are not
- saved in the history list. A value of _\bi_\bg_\bn_\bo_\br_\be_\bd_\bu_\bp_\bs causes lines
- matching the previous history entry to not be saved. A value of
- _\bi_\bg_\bn_\bo_\br_\be_\bb_\bo_\bt_\bh is shorthand for _\bi_\bg_\bn_\bo_\br_\be_\bs_\bp_\ba_\bc_\be and _\bi_\bg_\bn_\bo_\br_\be_\bd_\bu_\bp_\bs. A value
+ saved in the history list. A value of _\bi_\bg_\bn_\bo_\br_\be_\bd_\bu_\bp_\bs causes lines
+ matching the previous history entry to not be saved. A value of
+ _\bi_\bg_\bn_\bo_\br_\be_\bb_\bo_\bt_\bh is shorthand for _\bi_\bg_\bn_\bo_\br_\be_\bs_\bp_\ba_\bc_\be and _\bi_\bg_\bn_\bo_\br_\be_\bd_\bu_\bp_\bs. A value
of _\be_\br_\ba_\bs_\be_\bd_\bu_\bp_\bs causes all previous lines matching the current line
to be removed from the history list before that line is saved.
Any value not in the above list is ignored. If H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL is
regardless of the value of H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL.
H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE
The name of the file in which command history is saved (see H\bHI\bIS\bS-\b-
- T\bTO\bOR\bRY\bY below). B\bBa\bas\bsh\bh assigns a default value of _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bh_\bi_\bs_\bt_\bo_\br_\by. If
- H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is unset or null, the command history is not saved when
- a shell exits.
+ T\bTO\bOR\bRY\bY below). B\bBa\bas\bsh\bh assigns a default value of _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bh_\bi_\bs_\bt_\bo_\br_\by.
+ If H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is unset or null, the command history is not saved
+ when a shell exits.
H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE
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, 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 a 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 trunca-
- tion. The shell sets the default value to the value of H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE
- after reading any startup files.
+ lines by removing the oldest entries. The history file is also
+ truncated to this size after writing it when a 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
+ H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE after reading any startup files.
H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE
A colon-separated list of patterns used to decide which command
- lines should be saved on the history list. Each pattern is an-
+ lines should be saved on the history list. Each pattern is an-
chored at the beginning of the line and must match the complete
line (no implicit `*\b*' is appended). Each pattern is tested
against the line after the checks specified by H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL are
applied. In addition to the normal shell pattern matching char-
- acters, `&\b&' matches the previous history line. `&\b&' may be es-
+ acters, `&\b&' matches the previous history line. `&\b&' may be es-
caped using a backslash; the backslash is removed before at-
- tempting a match. The second and subsequent lines of a multi-
+ tempting a match. The second and subsequent lines of a multi-
line compound command are not tested, and are added to the his-
- tory regardless of the value of H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE. The pattern matching
- honors the setting of the e\bex\bxt\btg\bgl\blo\bob\bb shell option.
+ tory regardless of the value of H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE. The pattern match-
+ ing honors the setting of the e\bex\bxt\btg\bgl\blo\bob\bb shell option.
H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE
The number of commands to remember in the command history (see
- H\bHI\bIS\bST\bTO\bOR\bRY\bY below). If the value is 0, commands are not saved in the
- history list. Numeric values less than zero result in every com-
- mand being saved on the history list (there is no limit). The
- shell sets the default value to 500 after reading any startup
- files.
+ H\bHI\bIS\bST\bTO\bOR\bRY\bY 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.
H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT
If this variable is set and not null, its value is used as a
format string for _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3) to print the time stamp associated
- with each history entry displayed by the h\bhi\bis\bst\bto\bor\bry\by builtin. If
+ with each history entry displayed by the h\bhi\bis\bst\bto\bor\bry\by 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.
H\bHO\bOM\bME\bE The home directory of the current user; the default argument for
- the c\bcd\bd builtin command. The value of this variable is also used
+ the c\bcd\bd builtin command. The value of this variable is also used
when performing tilde expansion.
H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE
Contains the name of a file in the same format as _\b/_\be_\bt_\bc_\b/_\bh_\bo_\bs_\bt_\bs
The list of possible hostname completions may be changed while
the shell is running; the next time hostname completion is at-
tempted after the value is changed, b\bba\bas\bsh\bh adds the contents of
- the new file to the existing list. If H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE is set, but has
+ the new file to the existing list. If H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE is set, but has
no value, or does not name a readable file, b\bba\bas\bsh\bh attempts to
read _\b/_\be_\bt_\bc_\b/_\bh_\bo_\bs_\bt_\bs to obtain the list of possible hostname comple-
- tions. When H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE is unset, the hostname list is cleared.
+ tions. When H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE is unset, the hostname list is cleared.
I\bIF\bFS\bS The _\bI_\bn_\bt_\be_\br_\bn_\ba_\bl _\bF_\bi_\be_\bl_\bd _\bS_\be_\bp_\ba_\br_\ba_\bt_\bo_\br that is used for word splitting af-
ter expansion and to split lines into words with the r\bre\bea\bad\bd
- builtin command. The default value is ``<space><tab><newline>''.
+ builtin command. The default value is ``<space><tab><new-
+ line>''.
I\bIG\bGN\bNO\bOR\bRE\bEE\bEO\bOF\bF
Controls the action of an interactive shell on receipt of an E\bEO\bOF\bF
- character as the sole input. If set, the value is the number of
- consecutive E\bEO\bOF\bF characters which must be typed as the first
- characters on an input line before b\bba\bas\bsh\bh 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, E\bEO\bOF\bF signifies the end
- of input to the shell.
+ character as the sole input. If set, the value is the number of
+ consecutive E\bEO\bOF\bF characters which must be typed as the first
+ characters on an input line before b\bba\bas\bsh\bh 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, E\bEO\bOF\bF signifies the
+ end of input to the shell.
I\bIN\bNP\bPU\bUT\bTR\bRC\bC
- The filename for the r\bre\bea\bad\bdl\bli\bin\bne\be startup file, overriding the de-
+ The filename for the r\bre\bea\bad\bdl\bli\bin\bne\be startup file, overriding the de-
fault of _\b~_\b/_\b._\bi_\bn_\bp_\bu_\bt_\br_\bc (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE below).
I\bIN\bNS\bSI\bID\bDE\bE_\b_E\bEM\bMA\bAC\bCS\bS
- If this variable appears in the environment when the shell
- starts, b\bba\bas\bsh\bh assumes that it is running inside an Emacs shell
- buffer and may disable line editing, depending on the value of
+ If this variable appears in the environment when the shell
+ starts, b\bba\bas\bsh\bh assumes that it is running inside an Emacs shell
+ buffer and may disable line editing, depending on the value of
T\bTE\bER\bRM\bM.
- L\bLA\bAN\bNG\bG Used to determine the locale category for any category not
+ L\bLA\bAN\bNG\bG Used to determine the locale category for any category not
specifically selected with a variable starting with L\bLC\bC_\b_.
- L\bLC\bC_\b_A\bAL\bLL\bL This variable overrides the value of L\bLA\bAN\bNG\bG and any other L\bLC\bC_\b_
+ L\bLC\bC_\b_A\bAL\bLL\bL This variable overrides the value of L\bLA\bAN\bNG\bG and any other L\bLC\bC_\b_
variable specifying a locale category.
L\bLC\bC_\b_C\bCO\bOL\bLL\bLA\bAT\bTE\bE
- 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 se-
+ 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 se-
quences within pathname expansion and pattern matching.
L\bLC\bC_\b_C\bCT\bTY\bYP\bPE\bE
- 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.
L\bLC\bC_\b_M\bME\bES\bSS\bSA\bAG\bGE\bES\bS
- This variable determines the locale used to translate double-
+ This variable determines the locale used to translate double-
quoted strings preceded by a $\b$.
L\bLC\bC_\b_N\bNU\bUM\bME\bER\bRI\bIC\bC
- This variable determines the locale category used for number
+ This variable determines the locale category used for number
formatting.
L\bLC\bC_\b_T\bTI\bIM\bME\bE
- This variable determines the locale category used for data and
+ This variable determines the locale category used for data and
time formatting.
- L\bLI\bIN\bNE\bES\bS Used by the s\bse\bel\ble\bec\bct\bt compound command to determine the column
- length for printing selection lists. Automatically set if the
- c\bch\bhe\bec\bck\bkw\bwi\bin\bns\bsi\biz\bze\be option is enabled or in an interactive shell upon
+ L\bLI\bIN\bNE\bES\bS Used by the s\bse\bel\ble\bec\bct\bt compound command to determine the column
+ length for printing selection lists. Automatically set if the
+ c\bch\bhe\bec\bck\bkw\bwi\bin\bns\bsi\biz\bze\be option is enabled or in an interactive shell upon
receipt of a S\bSI\bIG\bGW\bWI\bIN\bNC\bCH\bH.
- M\bMA\bAI\bIL\bL If this parameter is set to a file or directory name and the
- M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH variable is not set, b\bba\bas\bsh\bh informs the user of the ar-
+ M\bMA\bAI\bIL\bL If this parameter is set to a file or directory name and the
+ M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH variable is not set, b\bba\bas\bsh\bh informs the user of the ar-
rival of mail in the specified file or Maildir-format directory.
M\bMA\bAI\bIL\bLC\bCH\bHE\bEC\bCK\bK
- Specifies how often (in seconds) b\bba\bas\bsh\bh checks for mail. The de-
- fault 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) b\bba\bas\bsh\bh checks for mail. The de-
+ fault 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.
M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH
- A colon-separated list of filenames to be checked for mail. The
+ 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, $\b$_\b_ expands to the
- name of the current mailfile. Example:
+ be specified by separating the filename from the message with a
+ `?'. When used in the text of the message, $\b$_\b_ expands to the
+ name of the current mailfile. Example:
M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH='/var/mail/bfox?"You have mail":~/shell-mail?"$_ has
mail!"'
- B\bBa\bas\bsh\bh can be configured to supply a default value for this vari-
- able (there is no value by default), but the location of the
+ B\bBa\bas\bsh\bh can be configured to supply a default value for this vari-
+ able (there is no value by default), but the location of the
user mail files that it uses is system dependent (e.g.,
/var/mail/$\b$U\bUS\bSE\bER\bR).
O\bOP\bPT\bTE\bER\bRR\bR If set to the value 1, b\bba\bas\bsh\bh displays error messages generated by
- the g\bge\bet\bto\bop\bpt\bts\bs builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
- O\bOP\bPT\bTE\bER\bRR\bR is initialized to 1 each time the shell is invoked or a
+ the g\bge\bet\bto\bop\bpt\bts\bs builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
+ O\bOP\bPT\bTE\bER\bRR\bR is initialized to 1 each time the shell is invoked or a
shell script is executed.
- P\bPA\bAT\bTH\bH The search path for commands. It is a colon-separated list of
- directories in which the shell looks for commands (see C\bCO\bOM\bMM\bMA\bAN\bND\bD
- E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN below). A zero-length (null) directory name in the
- value of P\bPA\bAT\bTH\bH 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 b\bba\bas\bsh\bh. A common value is
+ P\bPA\bAT\bTH\bH The search path for commands. It is a colon-separated list of
+ directories in which the shell looks for commands (see C\bCO\bOM\bMM\bMA\bAN\bND\bD
+ E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN below). A zero-length (null) directory name in the
+ value of P\bPA\bAT\bTH\bH 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 b\bba\bas\bsh\bh. A common value is
``/usr/local/bin:/usr/lo-
cal/sbin:/usr/bin:/usr/sbin:/bin:/sbin''.
P\bPO\bOS\bSI\bIX\bXL\bLY\bY_\b_C\bCO\bOR\bRR\bRE\bEC\bCT\bT
- If this variable is in the environment when b\bba\bas\bsh\bh starts, the
- shell enters _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be before reading the startup files, as if
- the -\b--\b-p\bpo\bos\bsi\bix\bx invocation option had been supplied. If it is set
- while the shell is running, b\bba\bas\bsh\bh enables _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, as if the
- command _\bs_\be_\bt _\b-_\bo _\bp_\bo_\bs_\bi_\bx had been executed. When the shell enters
+ If this variable is in the environment when b\bba\bas\bsh\bh starts, the
+ shell enters _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be before reading the startup files, as if
+ the -\b--\b-p\bpo\bos\bsi\bix\bx invocation option had been supplied. If it is set
+ while the shell is running, b\bba\bas\bsh\bh enables _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, as if the
+ command _\bs_\be_\bt _\b-_\bo _\bp_\bo_\bs_\bi_\bx had been executed. When the shell enters
_\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, it sets this variable if it was not already set.
P\bPR\bRO\bOM\bMP\bPT\bT_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD
- If this variable is set, and is an array, the value of each set
- element is executed as a command prior to issuing each primary
- prompt. If this is set but not an array variable, its value is
+ If this variable is set, and is an array, the value of each set
+ element is executed as a command prior to issuing each primary
+ prompt. If this is set but not an array variable, its value is
used as a command to execute instead.
P\bPR\bRO\bOM\bMP\bPT\bT_\b_D\bDI\bIR\bRT\bTR\bRI\bIM\bM
- 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 \\b\w\bw and \\b\W\bW prompt string escapes (see P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below). Char-
- acters removed are replaced with an ellipsis.
- P\bPS\bS0\b0 The value of this parameter is expanded (see P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below)
- and displayed by interactive shells after reading a command and
+ the \\b\w\bw and \\b\W\bW prompt string escapes (see P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below).
+ Characters removed are replaced with an ellipsis.
+ P\bPS\bS0\b0 The value of this parameter is expanded (see P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below)
+ and displayed by interactive shells after reading a command and
before the command is executed.
- P\bPS\bS1\b1 The value of this parameter is expanded (see P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below)
- and used as the primary prompt string. The default value is
+ P\bPS\bS1\b1 The value of this parameter is expanded (see P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below)
+ and used as the primary prompt string. The default value is
``\\b\s\bs-\b-\\b\v\bv\\b\$\b$ ''.
- P\bPS\bS2\b2 The value of this parameter is expanded as with P\bPS\bS1\b1 and used as
- the secondary prompt string. The default is ``>\b> ''.
+ P\bPS\bS2\b2 The value of this parameter is expanded as with P\bPS\bS1\b1 and used as
+ the secondary prompt string. The default is ``>\b> ''.
P\bPS\bS3\b3 The value of this parameter is used as the prompt for the s\bse\bel\ble\bec\bct\bt
command (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR above).
- P\bPS\bS4\b4 The value of this parameter is expanded as with P\bPS\bS1\b1 and the
+ P\bPS\bS4\b4 The value of this parameter is expanded as with P\bPS\bS1\b1 and the
value is printed before each command b\bba\bas\bsh\bh displays during an ex-
- ecution trace. The first character of the expanded value of P\bPS\bS4\b4
+ ecution trace. The first character of the expanded value of P\bPS\bS4\b4
is replicated multiple times, as necessary, to indicate multiple
- levels of indirection. The default is ``+\b+ ''.
- S\bSH\bHE\bEL\bLL\bL This variable expands to the full pathname to the shell. If it
- is not set when the shell starts, b\bba\bas\bsh\bh assigns to it the full
+ levels of indirection. The default is ``+\b+ ''.
+ S\bSH\bHE\bEL\bLL\bL This variable expands to the full pathname to the shell. If it
+ is not set when the shell starts, b\bba\bas\bsh\bh assigns to it the full
pathname of the current user's login shell.
T\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT
- The value of this parameter is used as a format string specify-
- ing how the timing information for pipelines prefixed with the
- t\bti\bim\bme\be reserved word should be displayed. The %\b% 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
+ t\bti\bim\bme\be reserved word should be displayed. The %\b% 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.
%\b%%\b% A literal %\b%.
%\b%[\b[_\bp]\b][\b[l\bl]\b]R\bR The elapsed time in seconds.
%\b%[\b[_\bp]\b][\b[l\bl]\b]S\bS The number of CPU seconds spent in system mode.
%\b%P\bP The CPU percentage, computed as (%U + %S) / %R.
- The optional _\bp is a digit specifying the _\bp_\br_\be_\bc_\bi_\bs_\bi_\bo_\bn, the number
- of fractional digits after a decimal point. A value of 0 causes
- no decimal point or fraction to be output. At most six places
- after the decimal point may be specified; values of _\bp greater
- than 6 are changed to 6. If _\bp is not specified, the value 3 is
+ The optional _\bp is a digit specifying the _\bp_\br_\be_\bc_\bi_\bs_\bi_\bo_\bn, the number
+ of fractional digits after a decimal point. A value of 0 causes
+ no decimal point or fraction to be output. At most six places
+ after the decimal point may be specified; values of _\bp greater
+ than 6 are changed to 6. If _\bp is not specified, the value 3 is
used.
- The optional l\bl specifies a longer format, including minutes, of
- the form _\bM_\bMm_\bS_\bS._\bF_\bFs. The value of _\bp determines whether or not the
- fraction is included.
+ The optional l\bl specifies a longer format, including minutes, of
+ the form _\bM_\bMm_\bS_\bS._\bF_\bFs. The value of _\bp determines whether or not
+ the fraction is included.
- If this variable is not set, b\bba\bas\bsh\bh acts as if it had the value
- $\b$'\b'\\b\n\bnr\bre\bea\bal\bl\\b\t\bt%\b%3\b3l\blR\bR\\b\n\bnu\bus\bse\ber\br\\b\t\bt%\b%3\b3l\blU\bU\\b\n\bns\bsy\bys\bs\\b\t\bt%\b%3\b3l\blS\bS'\b'. If the value is null,
- b\bba\bas\bsh\bh does not display any timing information. A trailing newline
- is added when the format string is displayed.
+ If this variable is not set, b\bba\bas\bsh\bh acts as if it had the value
+ $\b$'\b'\\b\n\bnr\bre\bea\bal\bl\\b\t\bt%\b%3\b3l\blR\bR\\b\n\bnu\bus\bse\ber\br\\b\t\bt%\b%3\b3l\blU\bU\\b\n\bns\bsy\bys\bs\\b\t\bt%\b%3\b3l\blS\bS'\b'. If the value is null,
+ b\bba\bas\bsh\bh does not display any timing information. A trailing new-
+ line is added when the format string is displayed.
T\bTM\bMO\bOU\bUT\bT If set to a value greater than zero, T\bTM\bMO\bOU\bUT\bT is treated as the de-
- fault timeout for the r\bre\bea\bad\bd builtin. The s\bse\bel\ble\bec\bct\bt command termi-
+ fault timeout for the r\bre\bea\bad\bd builtin. The s\bse\bel\ble\bec\bct\bt command termi-
nates if input does not arrive after T\bTM\bMO\bOU\bUT\bT seconds when input is
- coming from a terminal. In an interactive shell, the value is
+ coming from a terminal. In an interactive shell, the value is
interpreted as the number of seconds to wait for a line of input
- after issuing the primary prompt. B\bBa\bas\bsh\bh terminates after waiting
- for that number of seconds if a complete line of input does not
+ after issuing the primary prompt. B\bBa\bas\bsh\bh terminates after waiting
+ for that number of seconds if a complete line of input does not
arrive.
- T\bTM\bMP\bPD\bDI\bIR\bR If set, b\bba\bas\bsh\bh uses its value as the name of a directory in which
+ T\bTM\bMP\bPD\bDI\bIR\bR If set, b\bba\bas\bsh\bh uses its value as the name of a directory in which
b\bba\bas\bsh\bh creates temporary files for the shell's use.
a\bau\but\bto\bo_\b_r\bre\bes\bsu\bum\bme\be
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 _\bn_\ba_\bm_\be of a
- stopped job, in this context, is the command line used to start
- it. If set to the value _\be_\bx_\ba_\bc_\bt, the string supplied must match
- the name of a stopped job exactly; if set to _\bs_\bu_\bb_\bs_\bt_\br_\bi_\bn_\bg, the
- string supplied needs to match a substring of the name of a
- stopped job. The _\bs_\bu_\bb_\bs_\bt_\br_\bi_\bn_\bg value provides functionality analo-
- gous to the %\b%?\b? job identifier (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL below). If set to
- any other value, the supplied string must be a prefix of a
+ 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 _\bn_\ba_\bm_\be of a
+ stopped job, in this context, is the command line used to start
+ it. If set to the value _\be_\bx_\ba_\bc_\bt, the string supplied must match
+ the name of a stopped job exactly; if set to _\bs_\bu_\bb_\bs_\bt_\br_\bi_\bn_\bg, the
+ string supplied needs to match a substring of the name of a
+ stopped job. The _\bs_\bu_\bb_\bs_\bt_\br_\bi_\bn_\bg value provides functionality analo-
+ gous to the %\b%?\b? job identifier (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL 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
%\b%_\bs_\bt_\br_\bi_\bn_\bg job identifier.
h\bhi\bis\bst\btc\bch\bha\bar\brs\bs
- The two or three characters which control history expansion and
- tokenization (see H\bHI\bIS\bST\bTO\bOR\bRY\bY E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN below). The first character
- is the _\bh_\bi_\bs_\bt_\bo_\br_\by _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn character, the character which signals
- the start of a history expansion, normally `!\b!'. The second char-
- acter is the _\bq_\bu_\bi_\bc_\bk _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\bt_\bi_\bo_\bn 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
- `^\b^'. 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 `#\b#'. The history comment
- character causes history substitution to be skipped for the re-
- maining words on the line. It does not necessarily cause the
+ The two or three characters which control history expansion and
+ tokenization (see H\bHI\bIS\bST\bTO\bOR\bRY\bY E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN below). The first character
+ is the _\bh_\bi_\bs_\bt_\bo_\br_\by _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn character, the character which signals
+ the start of a history expansion, normally `!\b!'. The second
+ character is the _\bq_\bu_\bi_\bc_\bk _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\bt_\bi_\bo_\bn 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
+ `^\b^'. 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 `#\b#'. The history com-
+ ment character causes history substitution to be skipped for the
+ remaining words on the line. It does not necessarily cause the
shell parser to treat the rest of the line as a comment.
A\bAr\brr\bra\bay\bys\bs
- B\bBa\bas\bsh\bh provides one-dimensional indexed and associative array variables.
- Any variable may be used as an indexed array; the d\bde\bec\bcl\bla\bar\bre\be 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
+ B\bBa\bas\bsh\bh provides one-dimensional indexed and associative array variables.
+ Any variable may be used as an indexed array; the d\bde\bec\bcl\bla\bar\bre\be 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 ref-
- erenced using arbitrary strings. Unless otherwise noted, indexed array
+ erenced using arbitrary strings. Unless otherwise noted, indexed array
indices must be non-negative integers.
- An indexed array is created automatically if any variable is assigned
- to using the syntax _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]=_\bv_\ba_\bl_\bu_\be. The _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt is treated as
- an arithmetic expression that must evaluate to a number. To explicitly
- declare an indexed array, use d\bde\bec\bcl\bla\bar\bre\be -\b-a\ba _\bn_\ba_\bm_\be (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bM-\b-
- M\bMA\bAN\bND\bDS\bS below). d\bde\bec\bcl\bla\bar\bre\be -\b-a\ba _\bn_\ba_\bm_\be[\b[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]\b] is also accepted; the _\bs_\bu_\bb_\b-
+ An indexed array is created automatically if any variable is assigned
+ to using the syntax _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]=_\bv_\ba_\bl_\bu_\be. The _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt is treated as
+ an arithmetic expression that must evaluate to a number. To explicitly
+ declare an indexed array, use d\bde\bec\bcl\bla\bar\bre\be -\b-a\ba _\bn_\ba_\bm_\be (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bM-\b-
+ M\bMA\bAN\bND\bDS\bS below). d\bde\bec\bcl\bla\bar\bre\be -\b-a\ba _\bn_\ba_\bm_\be[\b[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]\b] is also accepted; the _\bs_\bu_\bb_\b-
_\bs_\bc_\br_\bi_\bp_\bt is ignored.
Associative arrays are created using d\bde\bec\bcl\bla\bar\bre\be -\b-A\bA _\bn_\ba_\bm_\be.
Attributes may be specified for an array variable using the d\bde\bec\bcl\bla\bar\bre\be and
- r\bre\bea\bad\bdo\bon\bnl\bly\by builtins. Each attribute applies to all members of an array.
+ r\bre\bea\bad\bdo\bon\bnl\bly\by builtins. Each attribute applies to all members of an array.
- Arrays are assigned to using compound assignments of the form
- _\bn_\ba_\bm_\be=(\b(value_\b1 ... value_\bn)\b), where each _\bv_\ba_\bl_\bu_\be may be of the form [_\bs_\bu_\bb_\b-
- _\bs_\bc_\br_\bi_\bp_\bt]=_\bs_\bt_\br_\bi_\bn_\bg. Indexed array assignments do not require anything but
- _\bs_\bt_\br_\bi_\bn_\bg. Each _\bv_\ba_\bl_\bu_\be in the list is expanded using the shell expansions
+ Arrays are assigned to using compound assignments of the form
+ _\bn_\ba_\bm_\be=(\b(value_\b1 ... value_\bn)\b), where each _\bv_\ba_\bl_\bu_\be may be of the form [_\bs_\bu_\bb_\b-
+ _\bs_\bc_\br_\bi_\bp_\bt]=_\bs_\bt_\br_\bi_\bn_\bg. Indexed array assignments do not require anything but
+ _\bs_\bt_\br_\bi_\bn_\bg. Each _\bv_\ba_\bl_\bu_\be in the list is expanded using the shell expansions
described below under E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN, but _\bv_\ba_\bl_\bu_\bes that are valid variable as-
signments including the brackets and subscript do not undergo brace ex-
- pansion and word splitting, as with individual variable assignments.
- When assigning to indexed arrays, if the optional brackets and sub-
- script 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.
+ pansion and word splitting, as with individual variable assignments.
+ When assigning to indexed arrays, if the optional brackets and sub-
+ script 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 words in a compound assign-
- ment may be either assignment statements, for which the subscript is
- required, or a list of words that is interpreted as a sequence of al-
- ternating keys and values: _\bn_\ba_\bm_\be=(\b( _\bk_\be_\by_\b1 _\bv_\ba_\bl_\bu_\be_\b1 _\bk_\be_\by_\b2 _\bv_\ba_\bl_\bu_\be_\b2 ...)\b). These
- are treated identically to _\bn_\ba_\bm_\be=(\b( [_\bk_\be_\by_\b1]=_\bv_\ba_\bl_\bu_\be_\b1 [_\bk_\be_\by_\b2]=_\bv_\ba_\bl_\bu_\be_\b2 ...)\b). The
- first word in the list determines how the remaining words are inter-
- preted; all assignments in a list must be of the same type. When using
- key/value pairs, the keys may not be missing or empty; a final missing
- value is treated like the empty string.
-
- This syntax is also accepted by the d\bde\bec\bcl\bla\bar\bre\be builtin. Individual array
- elements may be assigned to using the _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]=_\bv_\ba_\bl_\bu_\be syntax in-
- troduced above. When assigning to an indexed array, if _\bn_\ba_\bm_\be is sub-
- scripted by a negative number, that number is interpreted as relative
- to one greater than the maximum index of _\bn_\ba_\bm_\be, so negative indices
+ ment may be either assignment statements, for which the subscript is
+ required, or a list of words that is interpreted as a sequence of al-
+ ternating keys and values: _\bn_\ba_\bm_\be=(\b( _\bk_\be_\by_\b1 _\bv_\ba_\bl_\bu_\be_\b1 _\bk_\be_\by_\b2 _\bv_\ba_\bl_\bu_\be_\b2 ...)\b). These
+ are treated identically to _\bn_\ba_\bm_\be=(\b( [_\bk_\be_\by_\b1]=_\bv_\ba_\bl_\bu_\be_\b1 [_\bk_\be_\by_\b2]=_\bv_\ba_\bl_\bu_\be_\b2 ...)\b).
+ The first word in the list determines how the remaining words are in-
+ terpreted; all assignments in a list must be of the same type. When
+ using key/value pairs, the keys may not be missing or empty; a final
+ missing value is treated like the empty string.
+
+ This syntax is also accepted by the d\bde\bec\bcl\bla\bar\bre\be builtin. Individual array
+ elements may be assigned to using the _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]=_\bv_\ba_\bl_\bu_\be syntax in-
+ troduced above. When assigning to an indexed array, if _\bn_\ba_\bm_\be is sub-
+ scripted by a negative number, that number is interpreted as relative
+ to one greater than the maximum index of _\bn_\ba_\bm_\be, so negative indices
count back from the end of the array, and an index of -1 references the
last element.
- The += operator will append to an array variable when assigning using
+ The += operator will append to an array variable when assigning using
the compound assignment syntax; see P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS above.
- Any element of an array may be referenced using ${_\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]}. The
- braces are required to avoid conflicts with pathname expansion. If _\bs_\bu_\bb_\b-
- _\bs_\bc_\br_\bi_\bp_\bt is @\b@ or *\b*, the word expands to all members of _\bn_\ba_\bm_\be, unless noted
- in the description of a builtin or word expansion. These subscripts
- differ only when the word appears within double quotes. If the word is
- double-quoted, ${_\bn_\ba_\bm_\be[*]} expands to a single word with the value of
- each array member separated by the first character of the I\bIF\bFS\bS special
- variable, and ${_\bn_\ba_\bm_\be[@]} expands each element of _\bn_\ba_\bm_\be to a separate
- word. When there are no array members, ${_\bn_\ba_\bm_\be[@]} 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 *\b* and @\b@ (see S\bSp\bpe\bec\bci\bia\bal\bl P\bPa\bar\bra\bam\bme\bet\bte\ber\brs\bs above). ${#_\bn_\ba_\bm_\be[_\bs_\bu_\bb_\b-
- _\bs_\bc_\br_\bi_\bp_\bt]} expands to the length of ${_\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]}. If _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt is *\b*
- or @\b@, the expansion is the number of elements in the array. If the _\bs_\bu_\bb_\b-
- _\bs_\bc_\br_\bi_\bp_\bt used to reference an element of an indexed array evaluates to a
- number less than zero, it is interpreted as relative to one greater
- than the maximum index of the array, so negative indices count back
- from the end of the array, and an index of -1 references the last ele-
- ment.
+ Any element of an array may be referenced using ${_\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]}.
+ The braces are required to avoid conflicts with pathname expansion. If
+ _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt is @\b@ or *\b*, the word expands to all members of _\bn_\ba_\bm_\be, unless
+ noted in the description of a builtin or word expansion. These sub-
+ scripts differ only when the word appears within double quotes. If the
+ word is double-quoted, ${_\bn_\ba_\bm_\be[*]} expands to a single word with the
+ value of each array member separated by the first character of the I\bIF\bFS\bS
+ special variable, and ${_\bn_\ba_\bm_\be[@]} expands each element of _\bn_\ba_\bm_\be to a sep-
+ arate word. When there are no array members, ${_\bn_\ba_\bm_\be[@]} expands to
+ nothing. If the double-quoted expansion occurs within a word, the ex-
+ pansion 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 *\b* and @\b@ (see S\bSp\bpe\bec\bci\bia\bal\bl P\bPa\bar\bra\bam\bme\bet\bte\ber\brs\bs above).
+ ${#_\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]} expands to the length of ${_\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt]}. If
+ _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt is *\b* or @\b@, the expansion is the number of elements in the ar-
+ ray. If the _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt used to reference an element of an indexed array
+ evaluates to a number less than zero, it is interpreted as relative to
+ one greater than the maximum index of the array, so negative indices
+ count back from the end of the array, and an index of -1 references the
+ last element.
Referencing an array variable without a subscript is equivalent to ref-
- erencing the array with a subscript of 0. Any reference to a variable
+ erencing the array with a subscript of 0. Any reference to a variable
using a valid subscript is valid, and b\bba\bas\bsh\bh will create an array if nec-
essary.
- An array variable is considered set if a subscript has been assigned a
- value. The null string is a valid value.
+ An array variable is considered set if a subscript has been assigned a
+ value. The null string is a valid value.
- It is possible to obtain the keys (indices) of an array as well as the
- values. ${!\b!_\bn_\ba_\bm_\be[_\b@]} and ${!\b!_\bn_\ba_\bm_\be[_\b*]} expand to the indices assigned in
- array variable _\bn_\ba_\bm_\be. The treatment when in double quotes is similar to
+ It is possible to obtain the keys (indices) of an array as well as the
+ values. ${!\b!_\bn_\ba_\bm_\be[_\b@]} and ${!\b!_\bn_\ba_\bm_\be[_\b*]} expand to the indices assigned in
+ array variable _\bn_\ba_\bm_\be. The treatment when in double quotes is similar to
the expansion of the special parameters _\b@ and _\b* within double quotes.
- The u\bun\bns\bse\bet\bt builtin is used to destroy arrays. u\bun\bns\bse\bet\bt _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt] de-
+ The u\bun\bns\bse\bet\bt builtin is used to destroy arrays. u\bun\bns\bse\bet\bt _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt] de-
stroys the array element at index _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt, for both indexed and asso-
- ciative arrays. Negative subscripts to indexed arrays are interpreted
- as described above. Unsetting the last element of an array variable
- does not unset the variable. u\bun\bns\bse\bet\bt _\bn_\ba_\bm_\be, where _\bn_\ba_\bm_\be is an array, re-
- moves the entire array. u\bun\bns\bse\bet\bt _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt], where _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt is *\b* or
+ ciative arrays. Negative subscripts to indexed arrays are interpreted
+ as described above. Unsetting the last element of an array variable
+ does not unset the variable. u\bun\bns\bse\bet\bt _\bn_\ba_\bm_\be, where _\bn_\ba_\bm_\be is an array, re-
+ moves the entire array. u\bun\bns\bse\bet\bt _\bn_\ba_\bm_\be[_\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt], where _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt is *\b* or
@\b@, behaves differently depending on whether _\bn_\ba_\bm_\be is an indexed or asso-
- ciative array. If _\bn_\ba_\bm_\be is an associative array, this unsets the element
- with subscript *\b* or @\b@. If _\bn_\ba_\bm_\be is an indexed array, unset removes all
- of the elements but does not remove the array itself.
+ ciative array. If _\bn_\ba_\bm_\be is an associative array, this unsets the ele-
+ ment with subscript *\b* or @\b@. If _\bn_\ba_\bm_\be is an indexed array, unset removes
+ all of the elements but does not remove the array itself.
- When using a variable name with a subscript as an argument to a com-
- mand, such as with u\bun\bns\bse\bet\bt, without using the word expansion syntax de-
- scribed above, the argument is subject to pathname expansion. If path-
+ When using a variable name with a subscript as an argument to a com-
+ mand, such as with u\bun\bns\bse\bet\bt, without using the word expansion syntax de-
+ scribed above, the argument is subject to pathname expansion. If path-
name expansion is not desired, the argument should be quoted.
- The d\bde\bec\bcl\bla\bar\bre\be, l\blo\boc\bca\bal\bl, and r\bre\bea\bad\bdo\bon\bnl\bly\by builtins each accept a -\b-a\ba option to
- specify an indexed array and a -\b-A\bA option to specify an associative ar-
- ray. If both options are supplied, -\b-A\bA takes precedence. The r\bre\bea\bad\bd
- builtin accepts a -\b-a\ba option to assign a list of words read from the
- standard input to an array. The s\bse\bet\bt and d\bde\bec\bcl\bla\bar\bre\be builtins display array
+ The d\bde\bec\bcl\bla\bar\bre\be, l\blo\boc\bca\bal\bl, and r\bre\bea\bad\bdo\bon\bnl\bly\by builtins each accept a -\b-a\ba option to
+ specify an indexed array and a -\b-A\bA option to specify an associative ar-
+ ray. If both options are supplied, -\b-A\bA takes precedence. The r\bre\bea\bad\bd
+ builtin accepts a -\b-a\ba option to assign a list of words read from the
+ standard input to an array. The s\bse\bet\bt and d\bde\bec\bcl\bla\bar\bre\be builtins display array
values in a way that allows them to be reused as assignments.
E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN
Expansion is performed on the command line after it has been split into
- words. There are seven kinds of expansion performed: _\bb_\br_\ba_\bc_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn,
- _\bt_\bi_\bl_\bd_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn, _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br _\ba_\bn_\bd _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn, _\bc_\bo_\bm_\bm_\ba_\bn_\bd _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\b-
+ words. There are seven kinds of expansion performed: _\bb_\br_\ba_\bc_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn,
+ _\bt_\bi_\bl_\bd_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn, _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br _\ba_\bn_\bd _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn, _\bc_\bo_\bm_\bm_\ba_\bn_\bd _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\b-
_\bt_\bi_\bo_\bn, _\ba_\br_\bi_\bt_\bh_\bm_\be_\bt_\bi_\bc _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn, _\bw_\bo_\br_\bd _\bs_\bp_\bl_\bi_\bt_\bt_\bi_\bn_\bg, and _\bp_\ba_\bt_\bh_\bn_\ba_\bm_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn.
The order of expansions is: brace expansion; tilde expansion, parameter
- and variable expansion, arithmetic expansion, and command substitution
- (done in a left-to-right fashion); word splitting; and pathname expan-
+ and variable expansion, arithmetic expansion, and command substitution
+ (done in a left-to-right fashion); word splitting; and pathname expan-
sion.
On systems that can support it, there is an additional expansion avail-
- able: _\bp_\br_\bo_\bc_\be_\bs_\bs _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\bt_\bi_\bo_\bn. This is performed at the same time as
- tilde, parameter, variable, and arithmetic expansion and command sub-
+ able: _\bp_\br_\bo_\bc_\be_\bs_\bs _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\bt_\bi_\bo_\bn. This is performed at the same time as
+ tilde, parameter, variable, and arithmetic expansion and command sub-
stitution.
- After these expansions are performed, quote characters present in the
- original word are removed unless they have been quoted themselves
+ After these expansions are performed, quote characters present in the
+ original word are removed unless they have been quoted themselves
(_\bq_\bu_\bo_\bt_\be _\br_\be_\bm_\bo_\bv_\ba_\bl).
- Only brace expansion, word splitting, and pathname expansion can in-
- crease the number of words of the expansion; other expansions expand a
- single word to a single word. The only exceptions to this are the ex-
+ Only brace expansion, word splitting, and pathname expansion can in-
+ crease the number of words of the expansion; other expansions expand a
+ single word to a single word. The only exceptions to this are the ex-
pansions of "$\b$@\b@" and "$\b${\b{_\bn_\ba_\bm_\be[\b[@\b@]\b]}\b}", and, in most cases, $\b$*\b* and
$\b${\b{_\bn_\ba_\bm_\be[\b[*\b*]\b]}\b} as explained above (see P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS).
B\bBr\bra\bac\bce\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
_\bB_\br_\ba_\bc_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn is a mechanism by which arbitrary strings may be gener-
- ated. This mechanism is similar to _\bp_\ba_\bt_\bh_\bn_\ba_\bm_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn, but the file-
- names generated need not exist. Patterns to be brace expanded take the
+ ated. This mechanism is similar to _\bp_\ba_\bt_\bh_\bn_\ba_\bm_\be _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn, but the file-
+ names generated need not exist. Patterns to be brace expanded take the
form of an optional _\bp_\br_\be_\ba_\bm_\bb_\bl_\be, followed by either a series of comma-sep-
- arated strings or a sequence expression between a pair of braces, fol-
- lowed by an optional _\bp_\bo_\bs_\bt_\bs_\bc_\br_\bi_\bp_\bt. The preamble is prefixed to each
+ arated strings or a sequence expression between a pair of braces, fol-
+ lowed by an optional _\bp_\bo_\bs_\bt_\bs_\bc_\br_\bi_\bp_\bt. 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, a{\b{d,c,b}\b}e
- expands into `ade ace abe'.
-
- A sequence expression takes the form {\b{_\bx.\b..\b._\by[\b[.\b..\b._\bi_\bn_\bc_\br]\b]}\b}, where _\bx and _\by are
- either integers or single letters, and _\bi_\bn_\bc_\br, an optional increment, is
- an integer. When integers are supplied, the expression expands to each
- number between _\bx and _\by, inclusive. Supplied integers may be prefixed
- with _\b0 to force each term to have the same width. When either _\bx or _\by
- begins with a zero, the shell attempts to force all generated terms to
- contain the same number of digits, zero-padding where necessary. When
- letters are supplied, the expression expands to each character lexico-
- graphically between _\bx and _\by, inclusive, using the default C locale.
- Note that both _\bx and _\by must be of the same type (integer or letter).
- When the increment is supplied, it is used as the difference between
- each term. The default increment is 1 or -1 as appropriate.
+ Brace expansions may be nested. The results of each expanded string
+ are not sorted; left to right order is preserved. For example,
+ a{\b{d,c,b}\b}e expands into `ade ace abe'.
+
+ A sequence expression takes the form {\b{_\bx.\b..\b._\by[\b[.\b..\b._\bi_\bn_\bc_\br]\b]}\b}, where _\bx and _\by are
+ either integers or single letters, and _\bi_\bn_\bc_\br, an optional increment, is
+ an integer. When integers are supplied, the expression expands to each
+ number between _\bx and _\by, inclusive. Supplied integers may be prefixed
+ with _\b0 to force each term to have the same width. When either _\bx or _\by
+ begins with a zero, the shell attempts to force all generated terms to
+ contain the same number of digits, zero-padding where necessary. When
+ letters are supplied, the expression expands to each character lexico-
+ graphically between _\bx and _\by, inclusive, using the default C locale.
+ Note that both _\bx and _\by must be of the same type (integer or letter).
+ 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. B\bBa\bas\bsh\bh does not apply any syntactic interpretation to
+ acters special to other expansions are preserved in the result. It is
+ strictly textual. B\bBa\bas\bsh\bh 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
+ A correctly-formed brace expansion must contain unquoted opening and
closing braces, and at least one unquoted comma or a valid sequence ex-
- pression. Any incorrectly formed brace expansion is left unchanged. A {\b{
- or ,\b, may be quoted with a backslash to prevent its being considered
- part of a brace expression. To avoid conflicts with parameter expan-
+ pression. Any incorrectly formed brace expansion is left unchanged. A
+ {\b{ or ,\b, may be quoted with a backslash to prevent its being considered
+ part of a brace expression. To avoid conflicts with parameter expan-
sion, the string $\b${\b{ is not considered eligible for brace expansion, and
inhibits brace expansion until the closing }\b}.
or
chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}}
- Brace expansion introduces a slight incompatibility with historical
- versions of s\bsh\bh. s\bsh\bh does not treat opening or closing braces specially
- when they appear as part of a word, and preserves them in the output.
- B\bBa\bas\bsh\bh removes braces from words as a consequence of brace expansion. For
- example, a word entered to s\bsh\bh as _\bf_\bi_\bl_\be_\b{_\b1_\b,_\b2_\b} appears identically in the
- output. The same word is output as _\bf_\bi_\bl_\be_\b1 _\bf_\bi_\bl_\be_\b2 after expansion by b\bba\bas\bsh\bh.
- If strict compatibility with s\bsh\bh is desired, start b\bba\bas\bsh\bh with the +\b+B\bB op-
- tion or disable brace expansion with the +\b+B\bB option to the s\bse\bet\bt command
- (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
+ Brace expansion introduces a slight incompatibility with historical
+ versions of s\bsh\bh. s\bsh\bh does not treat opening or closing braces specially
+ when they appear as part of a word, and preserves them in the output.
+ B\bBa\bas\bsh\bh removes braces from words as a consequence of brace expansion.
+ For example, a word entered to s\bsh\bh as _\bf_\bi_\bl_\be_\b{_\b1_\b,_\b2_\b} appears identically in
+ the output. The same word is output as _\bf_\bi_\bl_\be_\b1 _\bf_\bi_\bl_\be_\b2 after expansion by
+ b\bba\bas\bsh\bh. If strict compatibility with s\bsh\bh is desired, start b\bba\bas\bsh\bh with the
+ +\b+B\bB option or disable brace expansion with the +\b+B\bB option to the s\bse\bet\bt com-
+ mand (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
T\bTi\bil\bld\bde\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
- If a word begins with an unquoted tilde character (`~\b~'), all of the
- characters preceding the first unquoted slash (or all characters, if
- there is no unquoted slash) are considered a _\bt_\bi_\bl_\bd_\be_\b-_\bp_\br_\be_\bf_\bi_\bx. 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 _\bl_\bo_\bg_\bi_\bn _\bn_\ba_\bm_\be.
- If this login name is the null string, the tilde is replaced with the
- value of the shell parameter H\bHO\bOM\bME\bE. If H\bHO\bOM\bME\bE is unset, the home directory
- of the user executing the shell is substituted instead. Otherwise, the
- tilde-prefix is replaced with the home directory associated with the
- specified login name.
-
- If the tilde-prefix is a `~+', the value of the shell variable P\bPW\bWD\bD re-
- places the tilde-prefix. If the tilde-prefix is a `~-', the value of
- the shell variable O\bOL\bLD\bDP\bPW\bWD\bD, if it is set, is substituted. If the charac-
- ters following the tilde in the tilde-prefix consist of a number _\bN, op-
- tionally prefixed by a `+' or a `-', the tilde-prefix is replaced with
- the corresponding element from the directory stack, as it would be dis-
- played by the d\bdi\bir\brs\bs builtin invoked with the tilde-prefix as an argu-
- ment. If the characters following the tilde in the tilde-prefix consist
- of a number without a leading `+' or `-', `+' is assumed.
+ If a word begins with an unquoted tilde character (`~\b~'), all of the
+ characters preceding the first unquoted slash (or all characters, if
+ there is no unquoted slash) are considered a _\bt_\bi_\bl_\bd_\be_\b-_\bp_\br_\be_\bf_\bi_\bx. 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 _\bl_\bo_\bg_\bi_\bn _\bn_\ba_\bm_\be.
+ If this login name is the null string, the tilde is replaced with the
+ value of the shell parameter H\bHO\bOM\bME\bE. If H\bHO\bOM\bME\bE 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 P\bPW\bWD\bD re-
+ places the tilde-prefix. If the tilde-prefix is a `~-', the value of
+ the shell variable O\bOL\bLD\bDP\bPW\bWD\bD, if it is set, is substituted. If the char-
+ acters following the tilde in the tilde-prefix consist of a number _\bN,
+ 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 d\bdi\bir\brs\bs builtin invoked with the tilde-prefix as an argu-
+ 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
unchanged.
Each variable assignment is checked for unquoted tilde-prefixes immedi-
- ately following a :\b: or the first =\b=. In these cases, tilde expansion is
- also performed. Consequently, one may use filenames with tildes in as-
- signments to P\bPA\bAT\bTH\bH, M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH, and C\bCD\bDP\bPA\bAT\bTH\bH, and the shell assigns the ex-
+ ately following a :\b: or the first =\b=. In these cases, tilde expansion is
+ also performed. Consequently, one may use filenames with tildes in as-
+ signments to P\bPA\bAT\bTH\bH, M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH, and C\bCD\bDP\bPA\bAT\bTH\bH, and the shell assigns the ex-
panded value.
- B\bBa\bas\bsh\bh also performs tilde expansion on words satisfying the conditions
+ B\bBa\bas\bsh\bh also performs tilde expansion on words satisfying the conditions
of variable assignments (as described above under P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS) when they
- appear as arguments to simple commands. B\bBa\bas\bsh\bh does not do this, except
+ appear as arguments to simple commands. B\bBa\bas\bsh\bh does not do this, except
for the _\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn commands listed above, when in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be.
P\bPa\bar\bra\bam\bme\bet\bte\ber\br E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
The `$\b$' 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 `}\b}' not
+ When braces are used, the matching ending brace is the first `}\b}' not
escaped by a backslash or within a quoted string, and not within an em-
- bedded arithmetic expansion, command substitution, or parameter expan-
+ bedded arithmetic expansion, command substitution, or parameter expan-
sion.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br}
- The value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is substituted. The braces are required
- when _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a positional parameter with more than one
+ The value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is substituted. The braces are required
+ when _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a positional parameter with more than one
digit, or when _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is followed by a character which is not
- to be interpreted as part of its name. The _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a shell
- parameter as described above P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS) or an array reference
+ to be interpreted as part of its name. The _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a shell
+ parameter as described above P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS) or an array reference
(A\bAr\brr\bra\bay\bys\bs).
- If the first character of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an exclamation point (!\b!), and
- _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is not a _\bn_\ba_\bm_\be_\br_\be_\bf, it introduces a level of indirection. B\bBa\bas\bsh\bh
+ If the first character of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an exclamation point (!\b!), and
+ _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is not a _\bn_\ba_\bm_\be_\br_\be_\bf, it introduces a level of indirection. B\bBa\bas\bsh\bh
uses the value formed by expanding the rest of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br as the new _\bp_\ba_\b-
- _\br_\ba_\bm_\be_\bt_\be_\br; this is then expanded and that value is used in the rest of
- the expansion, rather than the expansion of the original _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br.
- This is known as _\bi_\bn_\bd_\bi_\br_\be_\bc_\bt _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn. The value is subject to tilde ex-
- pansion, parameter expansion, command substitution, and arithmetic ex-
- pansion. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a nameref, this expands to the name of the pa-
- rameter referenced by _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br instead of performing the complete in-
- direct expansion. The exceptions to this are the expansions of ${!\b!_\bp_\br_\be_\b-
- _\bf_\bi_\bx*\b*} and ${!\b!_\bn_\ba_\bm_\be[_\b@]} described below. The exclamation point must imme-
- diately follow the left brace in order to introduce indirection.
+ _\br_\ba_\bm_\be_\bt_\be_\br; this is then expanded and that value is used in the rest of
+ the expansion, rather than the expansion of the original _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br.
+ This is known as _\bi_\bn_\bd_\bi_\br_\be_\bc_\bt _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn. The value is subject to tilde ex-
+ pansion, parameter expansion, command substitution, and arithmetic ex-
+ pansion. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a nameref, this expands to the name of the
+ parameter referenced by _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br instead of performing the complete
+ indirect expansion. The exceptions to this are the expansions of
+ ${!\b!_\bp_\br_\be_\bf_\bi_\bx*\b*} and ${!\b!_\bn_\ba_\bm_\be[_\b@]} described below. The exclamation point
+ must immediately follow the left brace in order to introduce indirec-
+ tion.
In each of the cases below, _\bw_\bo_\br_\bd is subject to tilde expansion, parame-
ter expansion, command substitution, and arithmetic expansion.
When not performing substring expansion, using the forms documented be-
- low (e.g., :\b:-\b-), b\bba\bas\bsh\bh tests for a parameter that is unset or null. Omit-
- ting the colon results in a test only for a parameter that is unset.
+ low (e.g., :\b:-\b-), b\bba\bas\bsh\bh tests for a parameter that is unset or null.
+ Omitting the colon results in a test only for a parameter that is un-
+ set.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br:\b:-\b-_\bw_\bo_\br_\bd}
- U\bUs\bse\be D\bDe\bef\bfa\bau\bul\blt\bt V\bVa\bal\blu\bue\bes\bs. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is unset or null, the expansion
- of _\bw_\bo_\br_\bd is substituted. Otherwise, the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is
- substituted.
+ U\bUs\bse\be D\bDe\bef\bfa\bau\bul\blt\bt V\bVa\bal\blu\bue\bes\bs. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is unset or null, the expan-
+ sion of _\bw_\bo_\br_\bd is substituted. Otherwise, the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ is substituted.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br:\b:=\b=_\bw_\bo_\br_\bd}
- A\bAs\bss\bsi\big\bgn\bn D\bDe\bef\bfa\bau\bul\blt\bt V\bVa\bal\blu\bue\bes\bs. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is unset or null, the expan-
- sion of _\bw_\bo_\br_\bd is assigned to _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. The value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is
- then substituted. Positional parameters and special parameters
- may not be assigned to in this way.
+ A\bAs\bss\bsi\big\bgn\bn D\bDe\bef\bfa\bau\bul\blt\bt V\bVa\bal\blu\bue\bes\bs. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is unset or null, the ex-
+ pansion of _\bw_\bo_\br_\bd is assigned to _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. The value of _\bp_\ba_\br_\ba_\bm_\be_\b-
+ _\bt_\be_\br is then substituted. Positional parameters and special pa-
+ rameters may not be assigned to in this way.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br:\b:?\b?_\bw_\bo_\br_\bd}
- D\bDi\bis\bsp\bpl\bla\bay\by E\bEr\brr\bro\bor\br i\bif\bf N\bNu\bul\bll\bl o\bor\br U\bUn\bns\bse\bet\bt. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is null or unset,
- the expansion of _\bw_\bo_\br_\bd (or a message to that effect if _\bw_\bo_\br_\bd is
- not present) is written to the standard error and the shell, if
- it is not interactive, exits. Otherwise, the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ D\bDi\bis\bsp\bpl\bla\bay\by E\bEr\brr\bro\bor\br i\bif\bf N\bNu\bul\bll\bl o\bor\br U\bUn\bns\bse\bet\bt. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is null or unset,
+ the expansion of _\bw_\bo_\br_\bd (or a message to that effect if _\bw_\bo_\br_\bd is
+ not present) is written to the standard error and the shell, if
+ it is not interactive, exits. Otherwise, the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
is substituted.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br:\b:+\b+_\bw_\bo_\br_\bd}
- U\bUs\bse\be A\bAl\blt\bte\ber\brn\bna\bat\bte\be V\bVa\bal\blu\bue\be. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is null or unset, nothing is
+ U\bUs\bse\be A\bAl\blt\bte\ber\brn\bna\bat\bte\be V\bVa\bal\blu\bue\be. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is null or unset, nothing is
substituted, otherwise the expansion of _\bw_\bo_\br_\bd is substituted.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br:\b:_\bo_\bf_\bf_\bs_\be_\bt}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br:\b:_\bo_\bf_\bf_\bs_\be_\bt:\b:_\bl_\be_\bn_\bg_\bt_\bh}
- S\bSu\bub\bbs\bst\btr\bri\bin\bng\bg E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn. Expands to up to _\bl_\be_\bn_\bg_\bt_\bh characters of the
- value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br starting at the character specified by _\bo_\bf_\bf_\b-
- _\bs_\be_\bt. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, an indexed array subscripted by @\b@
- or *\b*, or an associative array name, the results differ as de-
- scribed below. If _\bl_\be_\bn_\bg_\bt_\bh is omitted, expands to the substring of
- the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br starting at the character specified by
- _\bo_\bf_\bf_\bs_\be_\bt and extending to the end of the value. _\bl_\be_\bn_\bg_\bt_\bh and _\bo_\bf_\bf_\bs_\be_\bt
+ S\bSu\bub\bbs\bst\btr\bri\bin\bng\bg E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn. Expands to up to _\bl_\be_\bn_\bg_\bt_\bh characters of the
+ value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br starting at the character specified by _\bo_\bf_\bf_\b-
+ _\bs_\be_\bt. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, an indexed array subscripted by @\b@
+ or *\b*, or an associative array name, the results differ as de-
+ scribed below. If _\bl_\be_\bn_\bg_\bt_\bh is omitted, expands to the substring
+ of the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br starting at the character specified by
+ _\bo_\bf_\bf_\bs_\be_\bt and extending to the end of the value. _\bl_\be_\bn_\bg_\bt_\bh and _\bo_\bf_\bf_\bs_\be_\bt
are arithmetic expressions (see A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN below).
- If _\bo_\bf_\bf_\bs_\be_\bt evaluates to a number less than zero, the value is
+ If _\bo_\bf_\bf_\bs_\be_\bt evaluates to a number less than zero, the value is
used as an offset in characters from the end of the value of _\bp_\ba_\b-
- _\br_\ba_\bm_\be_\bt_\be_\br. If _\bl_\be_\bn_\bg_\bt_\bh evaluates to a number less than zero, it is
+ _\br_\ba_\bm_\be_\bt_\be_\br. If _\bl_\be_\bn_\bg_\bt_\bh evaluates to a number less than zero, it is
interpreted as an offset in characters from the end of the value
- of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br rather than a number of characters, and the expan-
- sion is the characters between _\bo_\bf_\bf_\bs_\be_\bt and that result. Note that
- a negative offset must be separated from the colon by at least
- one space to avoid being confused with the :\b:-\b- expansion.
-
- If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the result is _\bl_\be_\bn_\bg_\bt_\bh positional parame-
- ters beginning at _\bo_\bf_\bf_\bs_\be_\bt. A negative _\bo_\bf_\bf_\bs_\be_\bt is taken relative to
- one greater than the greatest positional parameter, so an offset
- of -1 evaluates to the last positional parameter (or 0 if there
- are no positional parameters). It is an expansion error if
- _\bl_\be_\bn_\bg_\bt_\bh evaluates to a number less than zero.
+ of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br rather than a number of characters, and the expan-
+ sion is the characters between _\bo_\bf_\bf_\bs_\be_\bt and that result. Note
+ that a negative offset must be separated from the colon by at
+ least one space to avoid being confused with the :\b:-\b- expansion.
+
+ If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the result is _\bl_\be_\bn_\bg_\bt_\bh positional parame-
+ ters beginning at _\bo_\bf_\bf_\bs_\be_\bt. A negative _\bo_\bf_\bf_\bs_\be_\bt is taken relative
+ to one greater than the greatest positional parameter, so an
+ offset of -1 evaluates to the last positional parameter (or 0 if
+ there are no positional parameters). It is an expansion error
+ if _\bl_\be_\bn_\bg_\bt_\bh evaluates to a number less than zero.
If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an indexed array name subscripted by @ or *, the
- result is the _\bl_\be_\bn_\bg_\bt_\bh members of the array beginning with ${_\bp_\ba_\b-
- _\br_\ba_\bm_\be_\bt_\be_\br[_\bo_\bf_\bf_\bs_\be_\bt]}. A negative _\bo_\bf_\bf_\bs_\be_\bt is taken relative to one
- greater than the maximum index of the specified array. It is an
+ result is the _\bl_\be_\bn_\bg_\bt_\bh members of the array beginning with ${_\bp_\ba_\b-
+ _\br_\ba_\bm_\be_\bt_\be_\br[_\bo_\bf_\bf_\bs_\be_\bt]}. A negative _\bo_\bf_\bf_\bs_\be_\bt is taken relative to one
+ greater than the maximum index of the specified array. It is an
expansion error if _\bl_\be_\bn_\bg_\bt_\bh evaluates to a number less than zero.
Substring expansion applied to an associative array produces un-
defined results.
- Substring indexing is zero-based unless the positional parame-
- ters are used, in which case the indexing starts at 1 by de-
- fault. If _\bo_\bf_\bf_\bs_\be_\bt is 0, and the positional parameters are used,
+ Substring indexing is zero-based unless the positional parame-
+ ters are used, in which case the indexing starts at 1 by de-
+ fault. If _\bo_\bf_\bf_\bs_\be_\bt is 0, and the positional parameters are used,
$\b$0\b0 is prefixed to the list.
${!\b!_\bp_\br_\be_\bf_\bi_\bx*\b*}
${!\b!_\bp_\br_\be_\bf_\bi_\bx@\b@}
- N\bNa\bam\bme\bes\bs m\bma\bat\btc\bch\bhi\bin\bng\bg p\bpr\bre\bef\bfi\bix\bx. Expands to the names of variables whose
+ N\bNa\bam\bme\bes\bs m\bma\bat\btc\bch\bhi\bin\bng\bg p\bpr\bre\bef\bfi\bix\bx. Expands to the names of variables whose
names begin with _\bp_\br_\be_\bf_\bi_\bx, separated by the first character of the
- I\bIF\bFS\bS special variable. When _\b@ is used and the expansion appears
- within double quotes, each variable name expands to a separate
+ I\bIF\bFS\bS special variable. When _\b@ is used and the expansion appears
+ within double quotes, each variable name expands to a separate
word.
${!\b!_\bn_\ba_\bm_\be[_\b@]}
${!\b!_\bn_\ba_\bm_\be[_\b*]}
- L\bLi\bis\bst\bt o\bof\bf a\bar\brr\bra\bay\by k\bke\bey\bys\bs. If _\bn_\ba_\bm_\be is an array variable, expands to the
- list of array indices (keys) assigned in _\bn_\ba_\bm_\be. If _\bn_\ba_\bm_\be is not an
- array, expands to 0 if _\bn_\ba_\bm_\be is set and null otherwise. When _\b@ is
- used and the expansion appears within double quotes, each key
- expands to a separate word.
+ L\bLi\bis\bst\bt o\bof\bf a\bar\brr\bra\bay\by k\bke\bey\bys\bs. If _\bn_\ba_\bm_\be is an array variable, expands to
+ the list of array indices (keys) assigned in _\bn_\ba_\bm_\be. If _\bn_\ba_\bm_\be is
+ not an array, expands to 0 if _\bn_\ba_\bm_\be is set and null otherwise.
+ When _\b@ is used and the expansion appears within double quotes,
+ each key expands to a separate word.
${#\b#_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br}
- P\bPa\bar\bra\bam\bme\bet\bte\ber\br l\ble\ben\bng\bgt\bth\bh. The length in characters of the value of _\bp_\ba_\b-
- _\br_\ba_\bm_\be_\bt_\be_\br is substituted. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is *\b* or @\b@, the value sub-
- stituted is the number of positional parameters. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is
- an array name subscripted by *\b* or @\b@, the value substituted is
- the number of elements in the array. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an indexed
- array name subscripted by a negative number, that number is in-
- terpreted as relative to one greater than the maximum index of
- _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br, so negative indices count back from the end of the
+ P\bPa\bar\bra\bam\bme\bet\bte\ber\br l\ble\ben\bng\bgt\bth\bh. The length in characters of the value of _\bp_\ba_\b-
+ _\br_\ba_\bm_\be_\bt_\be_\br is substituted. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is *\b* or @\b@, the value sub-
+ stituted is the number of positional parameters. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ is an array name subscripted by *\b* or @\b@, the value substituted is
+ the number of elements in the array. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an indexed
+ array name subscripted by a negative number, that number is in-
+ terpreted as relative to one greater than the maximum index of
+ _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br, so negative indices count back from the end of the
array, and an index of -1 references the last element.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br#\b#_\bw_\bo_\br_\bd}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br#\b##\b#_\bw_\bo_\br_\bd}
- R\bRe\bem\bmo\bov\bve\be m\bma\bat\btc\bch\bhi\bin\bng\bg p\bpr\bre\bef\bfi\bix\bx p\bpa\bat\btt\bte\ber\brn\bn. The _\bw_\bo_\br_\bd is expanded to produce
+ R\bRe\bem\bmo\bov\bve\be m\bma\bat\btc\bch\bhi\bin\bng\bg p\bpr\bre\bef\bfi\bix\bx p\bpa\bat\btt\bte\ber\brn\bn. The _\bw_\bo_\br_\bd is expanded to produce
a pattern just as in pathname expansion, and matched against the
expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br using the rules described under P\bPa\bat\bt-\b-
- t\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. If the pattern matches the beginning of the
- value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br, then the result of the expansion is the ex-
- panded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br with the shortest matching pattern
- (the ``#\b#'' case) or the longest matching pattern (the ``#\b##\b#''
- case) deleted. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the pattern removal oper-
- ation is applied to each positional parameter in turn, and the
- expansion is the resultant list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array vari-
- able subscripted with @\b@ or *\b*, the pattern removal operation is
- applied to each member of the array in turn, and the expansion
+ t\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. If the pattern matches the beginning of
+ the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br, then the result of the expansion is the
+ expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br with the shortest matching pattern
+ (the ``#\b#'' case) or the longest matching pattern (the ``#\b##\b#''
+ case) deleted. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the pattern removal op-
+ eration is applied to each positional parameter in turn, and the
+ expansion is the resultant list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array vari-
+ able subscripted with @\b@ or *\b*, the pattern removal operation is
+ applied to each member of the array in turn, and the expansion
is the resultant list.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br%\b%_\bw_\bo_\br_\bd}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br%\b%%\b%_\bw_\bo_\br_\bd}
- R\bRe\bem\bmo\bov\bve\be m\bma\bat\btc\bch\bhi\bin\bng\bg s\bsu\buf\bff\bfi\bix\bx p\bpa\bat\btt\bte\ber\brn\bn. The _\bw_\bo_\br_\bd is expanded to produce
+ R\bRe\bem\bmo\bov\bve\be m\bma\bat\btc\bch\bhi\bin\bng\bg s\bsu\buf\bff\bfi\bix\bx p\bpa\bat\btt\bte\ber\brn\bn. The _\bw_\bo_\br_\bd is expanded to produce
a pattern just as in pathname expansion, and matched against the
expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br using the rules described under P\bPa\bat\bt-\b-
- t\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. If the pattern matches a trailing portion
- of the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br, then the result of the ex-
- pansion is the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br with the shortest
- matching pattern (the ``%\b%'' case) or the longest matching pat-
- tern (the ``%\b%%\b%'' case) deleted. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the pat-
- tern removal operation is applied to each positional parameter
- in turn, and the expansion is the resultant list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
- is an array variable subscripted with @\b@ or *\b*, the pattern re-
- moval operation is applied to each member of the array in turn,
- and the expansion is the resultant list.
+ t\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. If the pattern matches a trailing portion
+ of the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br, then the result of the ex-
+ pansion is the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br with the shortest
+ matching pattern (the ``%\b%'' case) or the longest matching pat-
+ tern (the ``%\b%%\b%'' case) deleted. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the
+ pattern removal operation is applied to each positional parame-
+ ter in turn, and the expansion is the resultant list. If _\bp_\ba_\br_\ba_\bm_\b-
+ _\be_\bt_\be_\br is an array variable subscripted with @\b@ or *\b*, the pattern
+ removal operation is applied to each member of the array in
+ turn, and the expansion is the resultant list.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br/\b/_\bp_\ba_\bt_\bt_\be_\br_\bn/\b/_\bs_\bt_\br_\bi_\bn_\bg}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br/\b//\b/_\bp_\ba_\bt_\bt_\be_\br_\bn/\b/_\bs_\bt_\br_\bi_\bn_\bg}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br/\b/#\b#_\bp_\ba_\bt_\bt_\be_\br_\bn/\b/_\bs_\bt_\br_\bi_\bn_\bg}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br/\b/%\b%_\bp_\ba_\bt_\bt_\be_\br_\bn/\b/_\bs_\bt_\br_\bi_\bn_\bg}
- P\bPa\bat\btt\bte\ber\brn\bn s\bsu\bub\bbs\bst\bti\bit\btu\but\bti\bio\bon\bn. The _\bp_\ba_\bt_\bt_\be_\br_\bn is expanded to produce a pat-
- tern just as in pathname expansion. _\bP_\ba_\br_\ba_\bm_\be_\bt_\be_\br is expanded and
- the longest match of _\bp_\ba_\bt_\bt_\be_\br_\bn against its value is replaced with
- _\bs_\bt_\br_\bi_\bn_\bg. _\bs_\bt_\br_\bi_\bn_\bg undergoes tilde expansion, parameter and variable
- expansion, arithmetic expansion, command and process substitu-
- tion, and quote removal. The match is performed using the rules
- described under P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. In the first form above,
- only the first match is replaced. If there are two slashes sepa-
- rating _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br and _\bp_\ba_\bt_\bt_\be_\br_\bn (the second form above), all
- matches of _\bp_\ba_\bt_\bt_\be_\br_\bn are replaced with _\bs_\bt_\br_\bi_\bn_\bg. If _\bp_\ba_\bt_\bt_\be_\br_\bn is pre-
- ceded by #\b# (the third form above), it must match at the begin-
- ning of the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. If _\bp_\ba_\bt_\bt_\be_\br_\bn is preceded
- by %\b% (the fourth form above), it must match at the end of the
- expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. If the expansion of _\bs_\bt_\br_\bi_\bn_\bg is null,
- matches of _\bp_\ba_\bt_\bt_\be_\br_\bn are deleted. If _\bs_\bt_\br_\bi_\bn_\bg is null, matches of
- _\bp_\ba_\bt_\bt_\be_\br_\bn are deleted and the /\b/ following _\bp_\ba_\bt_\bt_\be_\br_\bn may be omitted.
+ P\bPa\bat\btt\bte\ber\brn\bn s\bsu\bub\bbs\bst\bti\bit\btu\but\bti\bio\bon\bn. The _\bp_\ba_\bt_\bt_\be_\br_\bn is expanded to produce a pat-
+ tern just as in pathname expansion. _\bP_\ba_\br_\ba_\bm_\be_\bt_\be_\br is expanded and
+ the longest match of _\bp_\ba_\bt_\bt_\be_\br_\bn against its value is replaced with
+ _\bs_\bt_\br_\bi_\bn_\bg. _\bs_\bt_\br_\bi_\bn_\bg undergoes tilde expansion, parameter and vari-
+ able expansion, arithmetic expansion, command and process sub-
+ stitution, and quote removal. The match is performed using the
+ rules described under P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below. In the first form
+ above, only the first match is replaced. If there are two
+ slashes separating _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br and _\bp_\ba_\bt_\bt_\be_\br_\bn (the second form
+ above), all matches of _\bp_\ba_\bt_\bt_\be_\br_\bn are replaced with _\bs_\bt_\br_\bi_\bn_\bg. If
+ _\bp_\ba_\bt_\bt_\be_\br_\bn is preceded by #\b# (the third form above), it must match
+ at the beginning of the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. If _\bp_\ba_\bt_\bt_\be_\br_\bn
+ is preceded by %\b% (the fourth form above), it must match at the
+ end of the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. If the expansion of
+ _\bs_\bt_\br_\bi_\bn_\bg is null, matches of _\bp_\ba_\bt_\bt_\be_\br_\bn are deleted. If _\bs_\bt_\br_\bi_\bn_\bg is
+ null, matches of _\bp_\ba_\bt_\bt_\be_\br_\bn are deleted and the /\b/ following _\bp_\ba_\bt_\bt_\be_\br_\bn
+ may be omitted.
If the p\bpa\bat\bts\bsu\bub\bb_\b_r\bre\bep\bpl\bla\bac\bce\bem\bme\ben\bnt\bt shell option is enabled using s\bsh\bho\bop\bpt\bt,
any unquoted instances of &\b& in _\bs_\bt_\br_\bi_\bn_\bg are replaced with the
Quoting any part of _\bs_\bt_\br_\bi_\bn_\bg inhibits replacement in the expansion
of the quoted portion, including replacement strings stored in
- shell variables. Backslash will escape &\b& in _\bs_\bt_\br_\bi_\bn_\bg; the back-
+ shell variables. Backslash will escape &\b& in _\bs_\bt_\br_\bi_\bn_\bg; the back-
slash is removed in order to permit a literal &\b& in the replace-
- ment string. Backslash can also be used to escape a backslash;
- \\b\\\b\ results in a literal backslash in the replacement. Users
+ ment string. Backslash can also be used to escape a backslash;
+ \\b\\\b\ results in a literal backslash in the replacement. Users
should take care if _\bs_\bt_\br_\bi_\bn_\bg is double-quoted to avoid unwanted
interactions between the backslash and double-quoting, since
- backslash has special meaning within double quotes. Pattern sub-
- stitution performs the check for unquoted &\b& after expanding
+ backslash has special meaning within double quotes. Pattern
+ substitution performs the check for unquoted &\b& after expanding
_\bs_\bt_\br_\bi_\bn_\bg; shell programmers should quote any occurrences of &\b& they
want to be taken literally in the replacement and ensure any in-
stances of &\b& they want to be replaced are unquoted.
If the n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh shell option is enabled, the match is per-
- formed without regard to the case of alphabetic characters. If
+ formed without regard to the case of alphabetic characters. If
_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the substitution operation is applied to
each positional parameter in turn, and the expansion is the re-
- sultant list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array variable subscripted with
- @\b@ or *\b*, the substitution operation is applied to each member of
- the array in turn, and the expansion is the resultant list.
+ sultant list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array variable subscripted
+ with @\b@ or *\b*, the substitution operation is applied to each mem-
+ ber of the array in turn, and the expansion is the resultant
+ list.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br^\b^_\bp_\ba_\bt_\bt_\be_\br_\bn}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br^\b^^\b^_\bp_\ba_\bt_\bt_\be_\br_\bn}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br,\b,_\bp_\ba_\bt_\bt_\be_\br_\bn}
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br,\b,,\b,_\bp_\ba_\bt_\bt_\be_\br_\bn}
- C\bCa\bas\bse\be m\bmo\bod\bdi\bif\bfi\bic\bca\bat\bti\bio\bon\bn. This expansion modifies the case of alpha-
- betic characters in _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. The _\bp_\ba_\bt_\bt_\be_\br_\bn is expanded to pro-
- duce a pattern just as in pathname expansion. Each character in
- the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is tested against _\bp_\ba_\bt_\bt_\be_\br_\bn, and,
- if it matches the pattern, its case is converted. The pattern
- should not attempt to match more than one character. The ^\b^ oper-
- ator converts lowercase letters matching _\bp_\ba_\bt_\bt_\be_\br_\bn to uppercase;
+ C\bCa\bas\bse\be m\bmo\bod\bdi\bif\bfi\bic\bca\bat\bti\bio\bon\bn. This expansion modifies the case of alpha-
+ betic characters in _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. The _\bp_\ba_\bt_\bt_\be_\br_\bn is expanded to pro-
+ duce a pattern just as in pathname expansion. Each character in
+ the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is tested against _\bp_\ba_\bt_\bt_\be_\br_\bn, and,
+ if it matches the pattern, its case is converted. The pattern
+ should not attempt to match more than one character. The ^\b^ op-
+ erator converts lowercase letters matching _\bp_\ba_\bt_\bt_\be_\br_\bn to uppercase;
the ,\b, operator converts matching uppercase letters to lowercase.
- The ^\b^^\b^ and ,\b,,\b, expansions convert each matched character in the
- expanded value; the ^\b^ and ,\b, expansions match and convert only
- the first character in the expanded value. If _\bp_\ba_\bt_\bt_\be_\br_\bn is omit-
- ted, it is treated like a ?\b?, which matches every character. If
- _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the case modification operation is applied
- to each positional parameter in turn, and the expansion is the
- resultant list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array variable subscripted
- with @\b@ or *\b*, the case modification operation is applied to each
- member of the array in turn, and the expansion is the resultant
+ The ^\b^^\b^ and ,\b,,\b, expansions convert each matched character in the
+ expanded value; the ^\b^ and ,\b, expansions match and convert only
+ the first character in the expanded value. If _\bp_\ba_\bt_\bt_\be_\br_\bn is omit-
+ ted, it is treated like a ?\b?, which matches every character. If
+ _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the case modification operation is applied
+ to each positional parameter in turn, and the expansion is the
+ resultant list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array variable subscripted
+ with @\b@ or *\b*, the case modification operation is applied to each
+ member of the array in turn, and the expansion is the resultant
list.
${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br@\b@_\bo_\bp_\be_\br_\ba_\bt_\bo_\br}
- P\bPa\bar\bra\bam\bme\bet\bte\ber\br t\btr\bra\ban\bns\bsf\bfo\bor\brm\bma\bat\bti\bio\bon\bn. The expansion is either a transforma-
- tion of the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br or information about _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
- itself, depending on the value of _\bo_\bp_\be_\br_\ba_\bt_\bo_\br. Each _\bo_\bp_\be_\br_\ba_\bt_\bo_\br is a
+ P\bPa\bar\bra\bam\bme\bet\bte\ber\br t\btr\bra\ban\bns\bsf\bfo\bor\brm\bma\bat\bti\bio\bon\bn. The expansion is either a transforma-
+ tion of the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br or information about _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ itself, depending on the value of _\bo_\bp_\be_\br_\ba_\bt_\bo_\br. Each _\bo_\bp_\be_\br_\ba_\bt_\bo_\br is a
single letter:
- U\bU The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
- with lowercase alphabetic characters converted to upper-
+ U\bU The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ with lowercase alphabetic characters converted to upper-
case.
- u\bu The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ u\bu The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
with the first character converted to uppercase, if it is
alphabetic.
- L\bL The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
- with uppercase alphabetic characters converted to lower-
+ L\bL The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ with uppercase alphabetic characters converted to lower-
case.
- Q\bQ The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ Q\bQ The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
quoted in a format that can be reused as input.
- E\bE The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
- with backslash escape sequences expanded as with the
+ E\bE The expansion is a string that is the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ with backslash escape sequences expanded as with the
$\b$'\b'.\b..\b..\b.'\b' quoting mechanism.
P\bP The expansion is a string that is the result of expanding
the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br as if it were a prompt string (see
P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below).
- A\bA The expansion is a string in the form of an assignment
- statement or d\bde\bec\bcl\bla\bar\bre\be command that, if evaluated, will
+ A\bA The expansion is a string in the form of an assignment
+ statement or d\bde\bec\bcl\bla\bar\bre\be command that, if evaluated, will
recreate _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br with its attributes and value.
K\bK Produces a possibly-quoted version of the value of _\bp_\ba_\br_\ba_\bm_\b-
_\be_\bt_\be_\br, except that it prints the values of indexed and as-
- sociative arrays as a sequence of quoted key-value pairs
+ sociative arrays as a sequence of quoted key-value pairs
(see A\bAr\brr\bra\bay\bys\bs above).
- a\ba The expansion is a string consisting of flag values rep-
+ a\ba The expansion is a string consisting of flag values rep-
resenting _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br's attributes.
- k\bk Like the K transformation, but expands the keys and val-
- ues of indexed and associative arrays to separate words
+ k\bk Like the K transformation, but expands the keys and val-
+ ues of indexed and associative arrays to separate words
after word splitting.
- If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the operation is applied to each posi-
- tional parameter in turn, and the expansion is the resultant
- list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array variable subscripted with @\b@ or *\b*,
- the operation is applied to each member of the array in turn,
+ If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the operation is applied to each posi-
+ tional parameter in turn, and the expansion is the resultant
+ list. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an array variable subscripted with @\b@ or
+ *\b*, the operation is applied to each member of the array in turn,
and the expansion is the resultant list.
- The result of the expansion is subject to word splitting and
+ The result of the expansion is subject to word splitting and
pathname expansion as described below.
C\bCo\bom\bmm\bma\ban\bnd\bd S\bSu\bub\bbs\bst\bti\bit\btu\but\bti\bio\bon\bn
_\bC_\bo_\bm_\bm_\ba_\bn_\bd _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\bt_\bi_\bo_\bn allows the output of a command to replace the com-
- mand itself. There are two standard forms:
+ mand itself. There are two standard forms:
$\b$(\b(_\bc_\bo_\bm_\bm_\ba_\bn_\bd)\b)
or (deprecated)
B\bBa\bas\bsh\bh performs the expansion by executing _\bc_\bo_\bm_\bm_\ba_\bn_\bd in a subshell environ-
ment and replacing the command substitution with the standard output of
- the command, with any trailing newlines deleted. Embedded newlines are
- not deleted, but they may be removed during word splitting. The command
- substitution $\b$(\b(c\bca\bat\bt _\bf_\bi_\bl_\be)\b) can be replaced by the equivalent but faster
- $\b$(\b(<\b< _\bf_\bi_\bl_\be)\b).
+ the command, with any trailing newlines deleted. Embedded newlines are
+ not deleted, but they may be removed during word splitting. The com-
+ mand substitution $\b$(\b(c\bca\bat\bt _\bf_\bi_\bl_\be)\b) can be replaced by the equivalent but
+ faster $\b$(\b(<\b< _\bf_\bi_\bl_\be)\b).
- With the old-style backquote form of substitution, backslash retains
- its literal meaning except when followed by $\b$, `\b`, or \\b\. The first back-
- quote not preceded by a backslash terminates the command substitution.
- When using the $(_\bc_\bo_\bm_\bm_\ba_\bn_\bd) form, all characters between the parentheses
- make up the command; none are treated specially.
+ With the old-style backquote form of substitution, backslash retains
+ its literal meaning except when followed by $\b$, `\b`, or \\b\. The first
+ backquote not preceded by a backslash terminates the command substitu-
+ tion. When using the $(_\bc_\bo_\bm_\bm_\ba_\bn_\bd) form, all characters between the
+ parentheses make up the command; none are treated specially.
There is an alternate form of command substitution:
$\b${\b{_\bc _\bc_\bo_\bm_\bm_\ba_\bn_\bd;\b;}\b}
- which executes _\bc_\bo_\bm_\bm_\ba_\bn_\bd in the current execution environment and cap-
+ which executes _\bc_\bo_\bm_\bm_\ba_\bn_\bd in the current execution environment and cap-
tures its output, again with trailing newlines removed.
The character _\bc following the open brace must be a space, tab, newline,
- or |\b|, and the close brace must be in a position where a reserved word
- may appear (i.e., preceded by a command terminator such as semicolon).
+ or |\b|, and the close brace must be in a position where a reserved word
+ may appear (i.e., preceded by a command terminator such as semicolon).
B\bBa\bas\bsh\bh allows the close brace to be joined to the remaining characters in
- the word without being followed by a shell metacharacter as a reserved
+ the word without being followed by a shell metacharacter as a reserved
word would usually require.
Any side effects of _\bc_\bo_\bm_\bm_\ba_\bn_\bd take effect immediately in the current exe-
- cution environment and persist in the current environment after the
+ cution environment and persist in the current environment after the
command completes (e.g., the e\bex\bxi\bit\bt builtin will exit the shell).
- This type of command substitution superficially resembles executing an
- unnamed shell function: local variables are created as when a shell
- function is executing, and the r\bre\bet\btu\bur\brn\bn builtin forces _\bc_\bo_\bm_\bm_\ba_\bn_\bd to com-
- plete; however, the rest of the execution environment, including the
+ This type of command substitution superficially resembles executing an
+ unnamed shell function: local variables are created as when a shell
+ function is executing, and the r\bre\bet\btu\bur\brn\bn builtin forces _\bc_\bo_\bm_\bm_\ba_\bn_\bd to com-
+ plete; however, the rest of the execution environment, including the
positional parameters, is shared with the caller.
- If the first character following the open brace is a |\b|, the construct
- expands to the value of the R\bRE\bEP\bPL\bLY\bY shell variable after _\bc_\bo_\bm_\bm_\ba_\bn_\bd exe-
- cutes, without removing any trailing newlines, and the standard output
- of _\bc_\bo_\bm_\bm_\ba_\bn_\bd remains the same as in the calling shell. B\bBa\bas\bsh\bh creates R\bRE\bEP\bPL\bLY\bY
- as an initially-unset local variable when _\bc_\bo_\bm_\bm_\ba_\bn_\bd executes, and re-
- stores R\bRE\bEP\bPL\bLY\bY to the value it had before the command substitution after
+ If the first character following the open brace is a |\b|, the construct
+ expands to the value of the R\bRE\bEP\bPL\bLY\bY shell variable after _\bc_\bo_\bm_\bm_\ba_\bn_\bd exe-
+ cutes, without removing any trailing newlines, and the standard output
+ of _\bc_\bo_\bm_\bm_\ba_\bn_\bd remains the same as in the calling shell. B\bBa\bas\bsh\bh creates R\bRE\bE-\b-
+ P\bPL\bLY\bY as an initially-unset local variable when _\bc_\bo_\bm_\bm_\ba_\bn_\bd executes, and re-
+ stores R\bRE\bEP\bPL\bLY\bY to the value it had before the command substitution after
_\bc_\bo_\bm_\bm_\ba_\bn_\bd completes, as with any local variable.
- Command substitutions may be nested. To nest when using the backquoted
+ Command substitutions may be nested. To nest when using the backquoted
form, escape the inner backquotes with backslashes.
If the substitution appears within double quotes, b\bba\bas\bsh\bh does not perform
word splitting and pathname expansion on the results.
A\bAr\bri\bit\bth\bhm\bme\bet\bti\bic\bc E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
- Arithmetic expansion allows the evaluation of an arithmetic expression
- and the substitution of the result. The format for arithmetic expansion
- is:
+ Arithmetic expansion allows the evaluation of an arithmetic expression
+ and the substitution of the result. The format for arithmetic expan-
+ sion is:
$\b$(\b((\b(_\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn)\b))\b)
- The _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn undergoes the same expansions as if it were within dou-
- ble quotes, but double quote characters in _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn are not treated
- specially and are removed. All tokens in the expression undergo parame-
- ter and variable expansion, command substitution, and quote removal.
- The result is treated as the arithmetic expression to be evaluated.
+ The _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn undergoes the same expansions as if it were within dou-
+ ble quotes, but double quote characters in _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn are not treated
+ specially and are removed. All tokens in the expression undergo param-
+ eter and variable expansion, command substitution, and quote removal.
+ The result is treated as the arithmetic expression to be evaluated.
Arithmetic expansions may be nested.
- The evaluation is performed according to the rules listed below under
- A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN. If _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn is invalid, b\bba\bas\bsh\bh prints a message
+ The evaluation is performed according to the rules listed below under
+ A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN. If _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn is invalid, b\bba\bas\bsh\bh prints a message
indicating failure and no substitution occurs.
P\bPr\bro\boc\bce\bes\bss\bs S\bSu\bub\bbs\bst\bti\bit\btu\but\bti\bio\bon\bn
- _\bP_\br_\bo_\bc_\be_\bs_\bs _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\bt_\bi_\bo_\bn allows a process's input or output to be referred
- to using a filename. It takes the form of <\b<(\b(_\bl_\bi_\bs_\bt)\b) or >\b>(\b(_\bl_\bi_\bs_\bt)\b). The
- process _\bl_\bi_\bs_\bt is run asynchronously, and its input or output appears as
- a filename. This filename is passed as an argument to the current com-
- mand as the result of the expansion. If the >\b>(\b(_\bl_\bi_\bs_\bt)\b) form is used, writ-
- ing to the file will provide input for _\bl_\bi_\bs_\bt. If the <\b<(\b(_\bl_\bi_\bs_\bt)\b) form is
- used, the file passed as an argument should be read to obtain the out-
- put of _\bl_\bi_\bs_\bt. Process substitution is supported on systems that support
- named pipes (_\bF_\bI_\bF_\bO_\bs) or the /\b/d\bde\bev\bv/\b/f\bfd\bd method of naming open files.
-
- When available, process substitution is performed simultaneously with
- parameter and variable expansion, command substitution, and arithmetic
+ _\bP_\br_\bo_\bc_\be_\bs_\bs _\bs_\bu_\bb_\bs_\bt_\bi_\bt_\bu_\bt_\bi_\bo_\bn allows a process's input or output to be referred
+ to using a filename. It takes the form of <\b<(\b(_\bl_\bi_\bs_\bt)\b) or >\b>(\b(_\bl_\bi_\bs_\bt)\b). The
+ process _\bl_\bi_\bs_\bt is run asynchronously, and its input or output appears as
+ a filename. This filename is passed as an argument to the current com-
+ mand as the result of the expansion. If the >\b>(\b(_\bl_\bi_\bs_\bt)\b) form is used,
+ writing to the file will provide input for _\bl_\bi_\bs_\bt. If the <\b<(\b(_\bl_\bi_\bs_\bt)\b) form
+ is used, the file passed as an argument should be read to obtain the
+ output of _\bl_\bi_\bs_\bt. Process substitution is supported on systems that sup-
+ port named pipes (_\bF_\bI_\bF_\bO_\bs) or the /\b/d\bde\bev\bv/\b/f\bfd\bd method of naming open files.
+
+ When available, process substitution is performed simultaneously with
+ parameter and variable expansion, command substitution, and arithmetic
expansion.
W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg
- The shell scans the results of parameter expansion, command substitu-
- tion, and arithmetic expansion that did not occur within double quotes
+ The shell scans the results of parameter expansion, command substitu-
+ tion, and arithmetic expansion that did not occur within double quotes
for _\bw_\bo_\br_\bd _\bs_\bp_\bl_\bi_\bt_\bt_\bi_\bn_\bg.
- The shell treats each character of I\bIF\bFS\bS as a delimiter, and splits the
- results of the other expansions into words using these characters as
+ The shell treats each character of I\bIF\bFS\bS as a delimiter, and splits the
+ results of the other expansions into words using these characters as
field terminators.
If I\bIF\bFS\bS is unset, or its value is exactly <\b<s\bsp\bpa\bac\bce\be>\b><\b<t\bta\bab\bb>\b><\b<n\bne\bew\bwl\bli\bin\bne\be>\b>, the de-
- fault, then sequences of s\bsp\bpa\bac\bce\be, t\bta\bab\bb, and n\bne\bew\bwl\bli\bin\bne\be at the beginning and
- end of the results of the previous expansions are ignored, and any se-
- quence of I\bIF\bFS\bS characters not at the beginning or end serves to delimit
- words. If I\bIF\bFS\bS has a value other than the default, then sequences of the
- whitespace characters s\bsp\bpa\bac\bce\be, t\bta\bab\bb, and n\bne\bew\bwl\bli\bin\bne\be are ignored at the begin-
- ning and end of the word, as long as the whitespace character is in the
- value of I\bIF\bFS\bS (an I\bIF\bFS\bS whitespace character). Any character in I\bIF\bFS\bS that
- is not I\bIF\bFS\bS whitespace, along with any adjacent I\bIF\bFS\bS whitespace charac-
- ters, delimits a field. A sequence of I\bIF\bFS\bS whitespace characters is also
- treated as a delimiter.
-
- If the value of I\bIF\bFS\bS is null, no word splitting occurs. If I\bIF\bFS\bS is unset,
- word splitting behaves as if it contained the default value of
+ fault, then sequences of s\bsp\bpa\bac\bce\be, t\bta\bab\bb, and n\bne\bew\bwl\bli\bin\bne\be at the beginning and
+ end of the results of the previous expansions are ignored, and any se-
+ quence of I\bIF\bFS\bS characters not at the beginning or end serves to delimit
+ words. If I\bIF\bFS\bS has a value other than the default, then sequences of
+ the whitespace characters s\bsp\bpa\bac\bce\be, t\bta\bab\bb, and n\bne\bew\bwl\bli\bin\bne\be are ignored at the
+ beginning and end of the word, as long as the whitespace character is
+ in the value of I\bIF\bFS\bS (an I\bIF\bFS\bS whitespace character). Any character in
+ I\bIF\bFS\bS that is not I\bIF\bFS\bS whitespace, along with any adjacent I\bIF\bFS\bS whitespace
+ characters, delimits a field. A sequence of I\bIF\bFS\bS whitespace characters
+ is also treated as a delimiter.
+
+ If the value of I\bIF\bFS\bS is null, no word splitting occurs. If I\bIF\bFS\bS is un-
+ set, word splitting behaves as if it contained the default value of
<\b<s\bsp\bpa\bac\bce\be>\b><\b<t\bta\bab\bb>\b><\b<n\bne\bew\bwl\bli\bin\bne\be>\b>.
- Explicit null arguments ("\b""\b" or '\b''\b') are retained and passed to commands
- as empty strings. Unquoted implicit null arguments, resulting from the
- expansion of parameters that have no values, are removed. If a parame-
+ Explicit null arguments ("\b""\b" or '\b''\b') are retained and passed to commands
+ as empty strings. Unquoted implicit null arguments, resulting from the
+ expansion of parameters that have no values, are removed. If a parame-
ter with no value is expanded within double quotes, a null argument re-
- sults and is retained and passed to a command as an empty string. When
- a quoted null argument appears as part of a word whose expansion is
- non-null, the null argument is removed. That is, the word -d'' becomes
+ sults and is retained and passed to a command as an empty string. When
+ a quoted null argument appears as part of a word whose expansion is
+ non-null, the null argument is removed. That is, the word -d'' becomes
-d after word splitting and null argument removal.
Note that if no expansion occurs, no splitting is performed.
P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
- After word splitting, unless the -\b-f\bf option has been set, b\bba\bas\bsh\bh scans
- each word for the characters *\b*, ?\b?, and [\b[. If one of these characters
+ After word splitting, unless the -\b-f\bf option has been set, b\bba\bas\bsh\bh scans
+ each word for the characters *\b*, ?\b?, and [\b[. If one of these characters
appears, and is not quoted, then the word is regarded as a _\bp_\ba_\bt_\bt_\be_\br_\bn, and
- replaced with an alphabetically sorted list of filenames matching the
- pattern (see P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below). If no matching filenames are
- found, and the shell option n\bnu\bul\bll\blg\bgl\blo\bob\bb is not enabled, the word is left
- unchanged. If the n\bnu\bul\bll\blg\bgl\blo\bob\bb option is set, and no matches are found, the
- word is removed. If the f\bfa\bai\bil\blg\bgl\blo\bob\bb shell option is set, and no matches
- are found, an error message is printed and the command is not executed.
- If the shell option n\bno\boc\bca\bas\bse\beg\bgl\blo\bob\bb is enabled, the match is performed with-
- out regard to the case of alphabetic characters. When a pattern is used
- for pathname expansion, the character `\b``\b`.\b.'\b''\b' at the start of a name or
- immediately following a slash must be matched explicitly, unless the
- shell option d\bdo\bot\btg\bgl\blo\bob\bb is set. In order to match the filenames `\b``\b`.\b.'\b''\b' and
- `\b``\b`.\b..\b.'\b''\b', the pattern must begin with ``.'' (for example, ``.?''), even
- if d\bdo\bot\btg\bgl\blo\bob\bb is set. If the g\bgl\blo\bob\bbs\bsk\bki\bip\bpd\bdo\bot\bts\bs shell option is enabled, the
- filenames `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b' are never matched, even if the pattern be-
- gins with a `\b``\b`.\b.'\b''\b'. When not matching pathnames, the `\b``\b`.\b.'\b''\b' character is
- not treated specially. When matching a pathname, the slash character
- must always be matched explicitly by a slash in the pattern, but in
- other matching contexts it can be matched by a special pattern charac-
- ter as described below under P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg. See the description of
- s\bsh\bho\bop\bpt\bt below under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS for a description of the n\bno\bo-\b-
- c\bca\bas\bse\beg\bgl\blo\bob\bb, n\bnu\bul\bll\blg\bgl\blo\bob\bb, g\bgl\blo\bob\bbs\bsk\bki\bip\bpd\bdo\bot\bts\bs, f\bfa\bai\bil\blg\bgl\blo\bob\bb, and d\bdo\bot\btg\bgl\blo\bob\bb shell options.
+ replaced with an alphabetically sorted list of filenames matching the
+ pattern (see P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg below). If no matching filenames are
+ found, and the shell option n\bnu\bul\bll\blg\bgl\blo\bob\bb is not enabled, the word is left
+ unchanged. If the n\bnu\bul\bll\blg\bgl\blo\bob\bb option is set, and no matches are found,
+ the word is removed. If the f\bfa\bai\bil\blg\bgl\blo\bob\bb shell option is set, and no
+ matches are found, an error message is printed and the command is not
+ executed. If the shell option n\bno\boc\bca\bas\bse\beg\bgl\blo\bob\bb is enabled, the match is per-
+ formed without regard to the case of alphabetic characters. When a
+ pattern is used for pathname expansion, the character `\b``\b`.\b.'\b''\b' at the
+ start of a name or immediately following a slash must be matched ex-
+ plicitly, unless the shell option d\bdo\bot\btg\bgl\blo\bob\bb is set. In order to match
+ the filenames `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b', the pattern must begin with ``.'' (for
+ example, ``.?''), even if d\bdo\bot\btg\bgl\blo\bob\bb is set. If the g\bgl\blo\bob\bbs\bsk\bki\bip\bpd\bdo\bot\bts\bs shell
+ option is enabled, the filenames `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b' are never matched,
+ even if the pattern begins with a `\b``\b`.\b.'\b''\b'. When not matching pathnames,
+ the `\b``\b`.\b.'\b''\b' character is not treated specially. When matching a path-
+ name, the slash character must always be matched explicitly by a slash
+ in the pattern, but in other matching contexts it can be matched by a
+ special pattern character as described below under P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg.
+ See the description of s\bsh\bho\bop\bpt\bt below under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS for a
+ description of the n\bno\boc\bca\bas\bse\beg\bgl\blo\bob\bb, n\bnu\bul\bll\blg\bgl\blo\bob\bb, g\bgl\blo\bob\bbs\bsk\bki\bip\bpd\bdo\bot\bts\bs, f\bfa\bai\bil\blg\bgl\blo\bob\bb, and
+ d\bdo\bot\btg\bgl\blo\bob\bb shell options.
The G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE shell variable may be used to restrict the set of file
- names matching a _\bp_\ba_\bt_\bt_\be_\br_\bn. If G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is set, each matching file name
- that also matches one of the patterns in G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is removed from the
- list of matches. If the n\bno\boc\bca\bas\bse\beg\bgl\blo\bob\bb option is set, the matching against
- the patterns in G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is performed without regard to case. The
- filenames `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b' are always ignored when G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is set
- and not null. However, setting G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE to a non-null value has the
- effect of enabling the d\bdo\bot\btg\bgl\blo\bob\bb shell option, so all other filenames be-
- ginning with a `\b``\b`.\b.'\b''\b' will match. To get the old behavior of ignoring
- filenames beginning with a `\b``\b`.\b.'\b''\b', make `\b``\b`.\b.*\b*'\b''\b' one of the patterns in
- G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE. The d\bdo\bot\btg\bgl\blo\bob\bb option is disabled when G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is unset.
- The pattern matching honors the setting of the e\bex\bxt\btg\bgl\blo\bob\bb shell option.
-
- The G\bGL\bLO\bOB\bBS\bSO\bOR\bRT\bT variable controls how the results of pathname expansion
+ names matching a _\bp_\ba_\bt_\bt_\be_\br_\bn. If G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is set, each matching file
+ name that also matches one of the patterns in G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is removed
+ from the list of matches. If the n\bno\boc\bca\bas\bse\beg\bgl\blo\bob\bb option is set, the match-
+ ing against the patterns in G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE is performed without regard to
+ case. The filenames `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b' are always ignored when G\bGL\bLO\bOB\bBI\bIG\bG-\b-
+ N\bNO\bOR\bRE\bE is set and not null. However, setting G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE to a non-null
+ value has the effect of enabling the d\bdo\bot\btg\bgl\blo\bob\bb shell option, so all other
+ filenames beginning with a `\b``\b`.\b.'\b''\b' will match. To get the old behavior
+ of ignoring filenames beginning with a `\b``\b`.\b.'\b''\b', make `\b``\b`.\b.*\b*'\b''\b' one of the
+ patterns in G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE. The d\bdo\bot\btg\bgl\blo\bob\bb option is disabled when G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE
+ is unset. The pattern matching honors the setting of the e\bex\bxt\btg\bgl\blo\bob\bb shell
+ option.
+
+ The G\bGL\bLO\bOB\bBS\bSO\bOR\bRT\bT variable controls how the results of pathname expansion
are sorted, as described above.
P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg
Any character that appears in a pattern, other than the special pattern
- characters described below, matches itself. The NUL character may not
- occur in a pattern. A backslash escapes the following character; the
- escaping backslash is discarded when matching. The special pattern
+ characters described below, matches itself. The NUL character may not
+ occur in a pattern. A backslash escapes the following character; the
+ escaping backslash is discarded when matching. The special pattern
characters must be quoted if they are to be matched literally.
The special pattern characters have the following meanings:
- *\b* Matches any string, including the null string. When the
- g\bgl\blo\bob\bbs\bst\bta\bar\br shell option is enabled, and *\b* is used in a
- pathname expansion context, two adjacent *\b*s used as a
- single pattern will match all files and zero or more di-
- rectories and subdirectories. If followed by a /\b/, two ad-
- jacent *\b*s will match only directories and subdirectories.
+ *\b* Matches any string, including the null string. When the
+ g\bgl\blo\bob\bbs\bst\bta\bar\br shell option is enabled, and *\b* is used in a
+ pathname expansion context, two adjacent *\b*s used as a
+ single pattern will match all files and zero or more di-
+ rectories and subdirectories. If followed by a /\b/, two
+ adjacent *\b*s will match only directories and subdirecto-
+ ries.
?\b? Matches any single character.
- [\b[.\b..\b..\b.]\b] Matches any one of the enclosed characters. A pair of
+ [\b[.\b..\b..\b.]\b] Matches any one of the enclosed characters. A pair of
characters separated by a hyphen denotes a _\br_\ba_\bn_\bg_\be _\be_\bx_\bp_\br_\be_\bs_\b-
_\bs_\bi_\bo_\bn; any character that falls between those two charac-
ters, inclusive, using the current locale's collating se-
- quence and character set, is matched. If the first char-
- acter following the [\b[ is a !\b! or a ^\b^ then any character
- not enclosed is matched. The sorting order of characters
+ quence and character set, is matched. If the first char-
+ acter following the [\b[ is a !\b! or a ^\b^ then any character
+ not enclosed is matched. The sorting order of characters
in range expressions, and the characters included in the
range, are determined by the current locale and the val-
ues of the L\bLC\bC_\b_C\bCO\bOL\bLL\bLA\bAT\bTE\bE or L\bLC\bC_\b_A\bAL\bLL\bL shell variables, if set.
To obtain the traditional interpretation of range expres-
sions, where [\b[a\ba-\b-d\bd]\b] is equivalent to [\b[a\bab\bbc\bcd\bd]\b], set value of
the L\bLC\bC_\b_A\bAL\bLL\bL shell variable to C\bC, or enable the g\bgl\blo\bob\bba\bas\bsc\bci\bi-\b-
- i\bir\bra\ban\bng\bge\bes\bs shell option. A -\b- may be matched by including it
+ i\bir\bra\ban\bng\bge\bes\bs shell option. A -\b- may be matched by including it
as the first or last character in the set. A ]\b] may be
matched by including it as the first character in the
set.
a\bal\bln\bnu\bum\bm a\bal\blp\bph\bha\ba a\bas\bsc\bci\bii\bi b\bbl\bla\ban\bnk\bk c\bcn\bnt\btr\brl\bl d\bdi\big\bgi\bit\bt g\bgr\bra\bap\bph\bh l\blo\bow\bwe\ber\br p\bpr\bri\bin\bnt\bt
p\bpu\bun\bnc\bct\bt s\bsp\bpa\bac\bce\be u\bup\bpp\bpe\ber\br w\bwo\bor\brd\bd x\bxd\bdi\big\bgi\bit\bt
A character class matches any character belonging to that
- class. The w\bwo\bor\brd\bd character class matches letters, digits,
+ class. The w\bwo\bor\brd\bd character class matches letters, digits,
and the character _.
Within [\b[ and ]\b], an _\be_\bq_\bu_\bi_\bv_\ba_\bl_\be_\bn_\bc_\be _\bc_\bl_\ba_\bs_\bs can be specified us-
ing symbol _\bs_\by_\bm_\bb_\bo_\bl.
If the e\bex\bxt\btg\bgl\blo\bob\bb shell option is enabled using the s\bsh\bho\bop\bpt\bt builtin, the
- shell recognizes several extended pattern matching operators. In the
+ shell recognizes several extended pattern matching operators. In the
following description, a _\bp_\ba_\bt_\bt_\be_\br_\bn_\b-_\bl_\bi_\bs_\bt is a list of one or more patterns
- separated by a |\b|. Composite patterns may be formed using one or more of
- the following sub-patterns:
+ separated by a |\b|. Composite patterns may be formed using one or more
+ of the following sub-patterns:
?\b?(\b(_\bp_\ba_\bt_\bt_\be_\br_\bn_\b-_\bl_\bi_\bs_\bt)\b)
Matches zero or one occurrence of the given patterns
Matches anything except one of the given patterns
The e\bex\bxt\btg\bgl\blo\bob\bb option changes the behavior of the parser, since the paren-
- theses are normally treated as operators with syntactic meaning. To en-
- sure that extended matching patterns are parsed correctly, make sure
+ theses are normally treated as operators with syntactic meaning. To
+ ensure that extended matching patterns are parsed correctly, make sure
that e\bex\bxt\btg\bgl\blo\bob\bb is enabled before parsing constructs containing the pat-
terns, including shell functions and command substitutions.
names includes all files beginning with ``.'', but ``.'' and ``..''
must be matched by a pattern or sub-pattern that begins with a dot;
when it is disabled, the set does not include any filenames beginning
- with ``.'' unless the pattern or sub-pattern begins with a ``.''. As
+ with ``.'' unless the pattern or sub-pattern begins with a ``.''. As
above, ``.'' only has a special meaning when matching filenames.
Complicated extended pattern matching against long strings is slow, es-
pecially when the patterns contain alternations and the strings contain
- multiple matches. Using separate matches against shorter strings, or
+ multiple matches. Using separate matches against shorter strings, or
using arrays of strings instead of a single long string, may be faster.
Q\bQu\buo\bot\bte\be R\bRe\bem\bmo\bov\bva\bal\bl
R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN
Before a command is executed, its input and output may be _\br_\be_\bd_\bi_\br_\be_\bc_\bt_\be_\bd
- using a special notation interpreted by the shell. _\bR_\be_\bd_\bi_\br_\be_\bc_\bt_\bi_\bo_\bn allows
+ using a special notation interpreted by the shell. _\bR_\be_\bd_\bi_\br_\be_\bc_\bt_\bi_\bo_\bn allows
commands' file handles to be duplicated, opened, closed, made to refer
to different files, and can change the files the command reads from and
- writes to. Redirection may also be used to modify file handles in the
- current shell execution environment. The following redirection opera-
+ writes to. Redirection may also be used to modify file handles in the
+ current shell execution environment. The following redirection opera-
tors may precede or appear anywhere within a _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd or may fol-
- low a _\bc_\bo_\bm_\bm_\ba_\bn_\bd. Redirections are processed in the order they appear,
+ low a _\bc_\bo_\bm_\bm_\ba_\bn_\bd. Redirections are processed in the order they appear,
from left to right.
Each redirection that may be preceded by a file descriptor number may
- instead be preceded by a word of the form {_\bv_\ba_\br_\bn_\ba_\bm_\be}. In this case, for
+ instead be preceded by a word of the form {_\bv_\ba_\br_\bn_\ba_\bm_\be}. In this case, for
each redirection operator except >&- and <&-, the shell will allocate a
file descriptor greater than or equal to 10 and assign it to _\bv_\ba_\br_\bn_\ba_\bm_\be.
If >&- or <&- is preceded by {_\bv_\ba_\br_\bn_\ba_\bm_\be}, the value of _\bv_\ba_\br_\bn_\ba_\bm_\be defines
- the file descriptor to close. If {_\bv_\ba_\br_\bn_\ba_\bm_\be} is supplied, the redirection
- persists beyond the scope of the command, allowing the shell programmer
- to manage the file descriptor's lifetime manually. The v\bva\bar\brr\bre\bed\bdi\bir\br_\b_c\bcl\blo\bos\bse\be
- shell option manages this behavior.
+ the file descriptor to close. If {_\bv_\ba_\br_\bn_\ba_\bm_\be} is supplied, the redirect-
+ ion persists beyond the scope of the command, allowing the shell pro-
+ grammer to manage the file descriptor's lifetime manually. The
+ v\bva\bar\brr\bre\bed\bdi\bir\br_\b_c\bcl\blo\bos\bse\be shell option manages this behavior.
In the following descriptions, if the file descriptor number is omit-
ted, and the first character of the redirection operator is <\b<, the re-
- direction refers to the standard input (file descriptor 0). If the
+ direction refers to the standard input (file descriptor 0). If the
first character of the redirection operator is >\b>, the redirection
refers to the standard output (file descriptor 1).
tions, unless otherwise noted, is subjected to brace expansion, tilde
expansion, parameter and variable expansion, command substitution,
arithmetic expansion, quote removal, pathname expansion, and word
- splitting. If it expands to more than one word, b\bba\bas\bsh\bh reports an error.
+ splitting. If it expands to more than one word, b\bba\bas\bsh\bh reports an error.
Note that the order of redirections is significant. For example, the
command
put was redirected to _\bd_\bi_\br_\bl_\bi_\bs_\bt.
B\bBa\bas\bsh\bh handles several filenames specially when they are used in redirec-
- tions, as described in the following table. If the operating system on
+ tions, as described in the following table. If the operating system on
which b\bba\bas\bsh\bh is running provides these special files, bash will use them;
otherwise it will emulate them internally with the behavior described
below.
R\bRe\bed\bdi\bir\bre\bec\bct\bti\bin\bng\bg O\bOu\but\btp\bpu\but\bt
Redirection of output causes the file whose name results from the ex-
pansion of _\bw_\bo_\br_\bd to be opened for writing on file descriptor _\bn, or the
- standard output (file descriptor 1) if _\bn is not specified. If the file
+ standard output (file descriptor 1) if _\bn is not specified. If the file
does not exist it is created; if it does exist it is truncated to zero
size.
Redirection of output in this fashion causes the file whose name re-
sults from the expansion of _\bw_\bo_\br_\bd to be opened for appending on file de-
scriptor _\bn, or the standard output (file descriptor 1) if _\bn is not
- specified. If the file does not exist it is created.
+ specified. If the file does not exist it is created.
The general format for appending output is:
and
>\b>&\b&_\bw_\bo_\br_\bd
- Of the two forms, the first is preferred. This is semantically equiva-
+ Of the two forms, the first is preferred. This is semantically equiva-
lent to
>\b>_\bw_\bo_\br_\bd 2>\b>&\b&1
- When using the second form, _\bw_\bo_\br_\bd may not expand to a number or -\b-. If it
- does, other redirection operators apply (see D\bDu\bup\bpl\bli\bic\bca\bat\bti\bin\bng\bg F\bFi\bil\ble\be D\bDe\bes\bsc\bcr\bri\bip\bp-\b-
- t\bto\bor\brs\bs below) for compatibility reasons.
+ When using the second form, _\bw_\bo_\br_\bd may not expand to a number or -\b-. If
+ it does, other redirection operators apply (see D\bDu\bup\bpl\bli\bic\bca\bat\bti\bin\bng\bg F\bFi\bil\ble\be D\bDe\be-\b-
+ s\bsc\bcr\bri\bip\bpt\bto\bor\brs\bs below) for compatibility reasons.
A\bAp\bpp\bpe\ben\bnd\bdi\bin\bng\bg S\bSt\bta\ban\bnd\bda\bar\brd\bd O\bOu\but\btp\bpu\but\bt a\ban\bnd\bd S\bSt\bta\ban\bnd\bda\bar\brd\bd E\bEr\brr\bro\bor\br
This construct allows both the standard output (file descriptor 1) and
H\bHe\ber\bre\be D\bDo\boc\bcu\bum\bme\ben\bnt\bts\bs
This type of redirection instructs the shell to read input from the
- current source until a line containing only _\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br (with no trailing
- blanks) is seen. All of the lines read up to that point are then used
+ current source until it reads a line containing only _\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br (with no
+ trailing blanks). All of the lines read up to that point are then used
as the standard input (or file descriptor _\bn if _\bn is specified) for a
command.
expansion, or pathname expansion is performed on _\bw_\bo_\br_\bd.
If any part of _\bw_\bo_\br_\bd is quoted, the _\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br is the result of quote re-
- moval on _\bw_\bo_\br_\bd, and the lines in the here-document are not expanded. If
+ moval on _\bw_\bo_\br_\bd, and the lines in the here-document are not expanded. If
_\bw_\bo_\br_\bd is unquoted, the _\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br is _\bw_\bo_\br_\bd itself, all lines of the here-
document are subjected to parameter expansion, command substitution,
and arithmetic expansion, the character sequence \\b\<\b<n\bne\bew\bwl\bli\bin\bne\be>\b> is ignored,
[_\bn]<\b<<\b<<\b<_\bw_\bo_\br_\bd
The _\bw_\bo_\br_\bd undergoes tilde expansion, parameter and variable expansion,
- command substitution, arithmetic expansion, and quote removal. Pathname
- expansion and word splitting are not performed. The result is supplied
- as a single string, with a newline appended, to the command on its
- standard input (or file descriptor _\bn if _\bn is specified).
+ command substitution, arithmetic expansion, and quote removal. Path-
+ name expansion and word splitting are not performed. The result is
+ supplied as a single string, with a newline appended, to the command on
+ its standard input (or file descriptor _\bn if _\bn is specified).
D\bDu\bup\bpl\bli\bic\bca\bat\bti\bin\bng\bg F\bFi\bil\ble\be D\bDe\bes\bsc\bcr\bri\bip\bpt\bto\bor\brs\bs
The redirection operator
[_\bn]<\b<&\b&_\bw_\bo_\br_\bd
- is used to duplicate input file descriptors. If _\bw_\bo_\br_\bd expands to one or
+ is used to duplicate input file descriptors. If _\bw_\bo_\br_\bd expands to one or
more digits, the file descriptor denoted by _\bn is made to be a copy of
- that file descriptor. If the digits in _\bw_\bo_\br_\bd do not specify a file de-
- scriptor open for input, a redirection error occurs. If _\bw_\bo_\br_\bd evaluates
- to -\b-, file descriptor _\bn is closed. If _\bn is not specified, the standard
+ that file descriptor. If the digits in _\bw_\bo_\br_\bd do not specify a file de-
+ scriptor open for input, a redirection error occurs. If _\bw_\bo_\br_\bd evaluates
+ to -\b-, file descriptor _\bn is closed. If _\bn is not specified, the standard
input (file descriptor 0) is used.
The operator
[_\bn]>\b>&\b&_\bw_\bo_\br_\bd
- is used similarly to duplicate output file descriptors. If _\bn is not
- specified, the standard output (file descriptor 1) is used. If the dig-
- its in _\bw_\bo_\br_\bd do not specify a file descriptor open for output, a redi-
- rection error occurs. If _\bw_\bo_\br_\bd evaluates to -\b-, file descriptor _\bn is
- closed. As a special case, if _\bn is omitted, and _\bw_\bo_\br_\bd does not expand to
- one or more digits or -\b-, the standard output and standard error are
+ is used similarly to duplicate output file descriptors. If _\bn is not
+ specified, the standard output (file descriptor 1) is used. If the
+ digits in _\bw_\bo_\br_\bd do not specify a file descriptor open for output, a re-
+ direction error occurs. If _\bw_\bo_\br_\bd evaluates to -\b-, file descriptor _\bn is
+ closed. As a special case, if _\bn is omitted, and _\bw_\bo_\br_\bd does not expand
+ to one or more digits or -\b-, the standard output and standard error are
redirected as described previously.
M\bMo\bov\bvi\bin\bng\bg F\bFi\bil\ble\be D\bDe\bes\bsc\bcr\bri\bip\bpt\bto\bor\brs\bs
[_\bn]<\b<&\b&_\bd_\bi_\bg_\bi_\bt-\b-
moves the file descriptor _\bd_\bi_\bg_\bi_\bt to file descriptor _\bn, or the standard
- input (file descriptor 0) if _\bn is not specified. _\bd_\bi_\bg_\bi_\bt is closed after
+ input (file descriptor 0) if _\bn is not specified. _\bd_\bi_\bg_\bi_\bt is closed after
being duplicated to _\bn.
Similarly, the redirection operator
causes the file whose name is the expansion of _\bw_\bo_\br_\bd to be opened for
both reading and writing on file descriptor _\bn, or on file descriptor 0
- if _\bn is not specified. If the file does not exist, it is created.
+ if _\bn is not specified. If the file does not exist, it is created.
A\bAL\bLI\bIA\bAS\bSE\bES\bS
_\bA_\bl_\bi_\ba_\bs_\be_\bs allow a string to be substituted for a word that is in a posi-
If the shell reads an unquoted word in the right position, it checks
the word to see if it matches an alias name. If it matches, the shell
replaces the word with the alias value, and reads that value as if it
- had been read instead of the word. The shell doesn't look at any char-
+ had been read instead of the word. The shell doesn't look at any char-
acters following the word before attempting alias substitution.
The characters /\b/, $\b$, `\b`, and =\b= and any of the shell _\bm_\be_\bt_\ba_\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br_\bs or
- quoting characters listed above may not appear in an alias name. The
+ quoting characters listed above may not appear in an alias name. The
replacement text may contain any valid shell input, including shell
- metacharacters. The first word of the replacement text is tested for
+ metacharacters. The first word of the replacement text is tested for
aliases, but a word that is identical to an alias being expanded is not
- expanded a second time. This means that one may alias l\bls\bs to l\bls\bs -\b-F\bF, for
+ expanded a second time. This means that one may alias l\bls\bs to l\bls\bs -\b-F\bF, for
instance, and b\bba\bas\bsh\bh does not try to recursively expand the replacement
text.
Aliases are created and listed with the a\bal\bli\bia\bas\bs command, and removed with
the u\bun\bna\bal\bli\bia\bas\bs command.
- There is no mechanism for using arguments in the replacement text. If
+ There is no mechanism for using arguments in the replacement text. If
arguments are needed, use a shell function (see F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS below).
Aliases are not expanded when the shell is not interactive, unless the
s\bsh\bho\bop\bpt\bt under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
The rules concerning the definition and use of aliases are somewhat
- confusing. B\bBa\bas\bsh\bh always reads at least one complete line of input, and
+ confusing. B\bBa\bas\bsh\bh always reads at least one complete line of input, and
all lines that make up a compound command, before executing any of the
- commands on that line or the compound command. Aliases are expanded
+ commands on that line or the compound command. Aliases are expanded
when a command is read, not when it is executed. Therefore, an alias
definition appearing on the same line as another command does not take
- effect until the next line of input is read. The commands following the
- alias definition on that line are not affected by the new alias. This
- behavior is also an issue when functions are executed. Aliases are ex-
- panded when a function definition is read, not when the function is ex-
- ecuted, because a function definition is itself a command. As a conse-
- quence, aliases defined in a function are not available until after
- that function is executed. To be safe, always put alias definitions on
- a separate line, and do not use a\bal\bli\bia\bas\bs in compound commands.
+ effect until the next line of input is read. The commands following
+ the alias definition on that line are not affected by the new alias.
+ This behavior is also an issue when functions are executed. Aliases
+ are expanded when a function definition is read, not when the function
+ is executed, because a function definition is itself a command. As a
+ consequence, aliases defined in a function are not available until af-
+ ter that function is executed. To be safe, always put alias defini-
+ tions on a separate line, and do not use a\bal\bli\bia\bas\bs in compound commands.
For almost every purpose, aliases are superseded by shell functions.
F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS
A shell function, defined as described above under S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR,
- stores a series of commands for later execution. When the name of a
+ stores a series of commands for later execution. When the name of a
shell function is used as a simple command name, the list of commands
- associated with that function name is executed. Functions are executed
+ associated with that function name is executed. Functions are executed
in the context of the current shell; no new process is created to in-
- terpret them (contrast this with the execution of a shell script). When
- a function is executed, the arguments to the function become the posi-
- tional parameters during its execution. The special parameter #\b# is up-
- dated to reflect the change. Special parameter 0\b0 is unchanged. The
+ terpret them (contrast this with the execution of a shell script).
+ When a function is executed, the arguments to the function become the
+ positional parameters during its execution. The special parameter #\b# is
+ updated to reflect the change. Special parameter 0\b0 is unchanged. The
first element of the F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE variable is set to the name of the func-
tion while the function is executing.
option has been enabled.
Variables local to the function may be declared with the l\blo\boc\bca\bal\bl builtin
- command (_\bl_\bo_\bc_\ba_\bl _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be_\bs). Ordinarily, variables and their values are
- shared between the function and its caller. If a variable is declared
+ command (_\bl_\bo_\bc_\ba_\bl _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be_\bs). Ordinarily, variables and their values are
+ shared between the function and its caller. If a variable is declared
l\blo\boc\bca\bal\bl, the variable's visible scope is restricted to that function and
its children (including the functions it calls).
In the following description, the _\bc_\bu_\br_\br_\be_\bn_\bt _\bs_\bc_\bo_\bp_\be is a currently- execut-
- ing function. Previous scopes consist of that function's caller and so
+ ing function. Previous scopes consist of that function's caller and so
on, back to the "global" scope, where the shell is not executing any
- shell function. Consequently, a local variable at the current scope is
+ shell function. Consequently, a local variable at the current scope is
a variable declared using the l\blo\boc\bca\bal\bl or d\bde\bec\bcl\bla\bar\bre\be builtins in the function
that is currently executing.
Local variables "shadow" variables with the same name declared at pre-
- vious scopes. For instance, a local variable declared in a function
+ vious scopes. For instance, a local variable declared in a function
hides a global variable of the same name: references and assignments
refer to the local variable, leaving the global variable unmodified.
When the function returns, the global variable is once again visible.
The shell uses _\bd_\by_\bn_\ba_\bm_\bi_\bc _\bs_\bc_\bo_\bp_\bi_\bn_\bg to control a variable's visibility
- within functions. With dynamic scoping, visible variables and their
+ within functions. With dynamic scoping, visible variables and their
values are a result of the sequence of function calls that caused exe-
- cution to reach the current function. The value of a variable that a
+ cution to reach the current function. The value of a variable that a
function sees depends on its value within its caller, if any, whether
- that caller is the "global" scope or another shell function. This is
+ that caller is the "global" scope or another shell function. This is
also the value that a local variable declaration "shadows", and the
value that is restored when the function returns.
The u\bun\bns\bse\bet\bt builtin also acts using the same dynamic scope: if a variable
is local to the current scope, u\bun\bns\bse\bet\bt will unset it; otherwise the unset
will refer to the variable found in any calling scope as described
- above. If a variable at the current local scope is unset, it will re-
+ above. If a variable at the current local scope is unset, it will re-
main so (appearing as unset) until it is reset in that scope or until
the function returns. Once the function returns, any instance of the
- variable at a previous scope will become visible. If the unset acts on
+ variable at a previous scope will become visible. If the unset acts on
a variable at a previous scope, any instance of a variable with that
name that had been shadowed will become visible (see below how the l\blo\bo-\b-
c\bca\bal\blv\bva\bar\br_\b_u\bun\bns\bse\bet\bt shell option changes this behavior).
The F\bFU\bUN\bNC\bCN\bNE\bES\bST\bT variable, if set to a numeric value greater than 0, de-
- fines a maximum function nesting level. Function invocations that ex-
+ fines a maximum function nesting level. Function invocations that ex-
ceed the limit cause the entire command to abort.
If the builtin command r\bre\bet\btu\bur\brn\bn is executed in a function, the function
completes and execution resumes with the next command after the func-
- tion call. Any command associated with the R\bRE\bET\bTU\bUR\bRN\bN trap is executed be-
- fore execution resumes. When a function completes, the values of the
+ tion call. Any command associated with the R\bRE\bET\bTU\bUR\bRN\bN trap is executed be-
+ fore execution resumes. When a function completes, the values of the
positional parameters and the special parameter #\b# are restored to the
values they had prior to the function's execution.
Function names and definitions may be listed with the -\b-f\bf option to the
- d\bde\bec\bcl\bla\bar\bre\be or t\bty\byp\bpe\bes\bse\bet\bt builtin commands. The -\b-F\bF option to d\bde\bec\bcl\bla\bar\bre\be or t\bty\byp\bpe\be-\b-
+ d\bde\bec\bcl\bla\bar\bre\be or t\bty\byp\bpe\bes\bse\bet\bt builtin commands. The -\b-F\bF option to d\bde\bec\bcl\bla\bar\bre\be or t\bty\byp\bpe\be-\b-
s\bse\bet\bt will list the function names only (and optionally the source file
- and line number, if the e\bex\bxt\btd\bde\beb\bbu\bug\bg shell option is enabled). Functions
+ and line number, if the e\bex\bxt\btd\bde\beb\bbu\bug\bg shell option is enabled). Functions
may be exported so that child shell processes (those created when exe-
cuting a separate shell invocation) automatically have them defined
- with the -\b-f\bf option to the e\bex\bxp\bpo\bor\brt\bt builtin. A function definition may be
+ with the -\b-f\bf option to the e\bex\bxp\bpo\bor\brt\bt builtin. A function definition may be
deleted using the -\b-f\bf option to the u\bun\bns\bse\bet\bt builtin.
- Functions may be recursive. The F\bFU\bUN\bNC\bCN\bNE\bES\bST\bT variable may be used to limit
+ Functions may be recursive. The F\bFU\bUN\bNC\bCN\bNE\bES\bST\bT variable may be used to limit
the depth of the function call stack and restrict the number of func-
- tion invocations. By default, no limit is imposed on the number of re-
+ tion invocations. By default, no limit is imposed on the number of re-
cursive calls.
A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN
The shell allows arithmetic expressions to be evaluated, under certain
circumstances (see the l\ble\bet\bt and d\bde\bec\bcl\bla\bar\bre\be builtin commands, the (\b((\b( com-
- pound command, and A\bAr\bri\bit\bth\bhm\bme\bet\bti\bic\bc E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn). Evaluation is done in fixed-
+ pound command, and A\bAr\bri\bit\bth\bhm\bme\bet\bti\bic\bc E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn). Evaluation is done in fixed-
width integers with no check for overflow, though division by 0 is
- trapped and flagged as an error. The operators and their precedence,
- associativity, and values are the same as in the C language. The fol-
+ trapped and flagged as an error. The operators and their precedence,
+ associativity, and values are the same as in the C language. The fol-
lowing list of operators is grouped into levels of equal-precedence op-
- erators. The levels are listed in order of decreasing precedence.
+ erators. The levels are listed in order of decreasing precedence.
_\bi_\bd+\b++\b+ _\bi_\bd-\b--\b-
variable post-increment and post-decrement
comma
Shell variables are allowed as operands; parameter expansion is per-
- formed before the expression is evaluated. Within an expression, shell
+ formed before the expression is evaluated. Within an expression, shell
variables may also be referenced by name without using the parameter
- expansion syntax. A shell variable that is null or unset evaluates to 0
- when referenced by name without using the parameter expansion syntax.
+ expansion syntax. A shell variable that is null or unset evaluates to
+ 0 when referenced by name without using the parameter expansion syntax.
The value of a variable is evaluated as an arithmetic expression when
it is referenced, or when a variable which has been given the _\bi_\bn_\bt_\be_\bg_\be_\br
- attribute using d\bde\bec\bcl\bla\bar\bre\be -\b-i\bi is assigned a value. A null value evaluates
- to 0. A shell variable need not have its _\bi_\bn_\bt_\be_\bg_\be_\br attribute turned on to
- be used in an expression.
+ attribute using d\bde\bec\bcl\bla\bar\bre\be -\b-i\bi is assigned a value. A null value evaluates
+ to 0. A shell variable need not have its _\bi_\bn_\bt_\be_\bg_\be_\br attribute turned on
+ to be used in an expression.
Integer constants follow the C language definition, without suffixes or
- character constants. Constants with a leading 0 are interpreted as oc-
- tal numbers. A leading 0x or 0X denotes hexadecimal. Otherwise, numbers
- take the form [_\bb_\ba_\bs_\be_\b#]n, where the optional _\bb_\ba_\bs_\be is a decimal number be-
- tween 2 and 64 representing the arithmetic base, and _\bn is a number in
- that base. If _\bb_\ba_\bs_\be_\b# is omitted, then base 10 is used. When specifying
- _\bn, if a non-digit is required, the digits greater than 9 are repre-
- sented by the lowercase letters, the uppercase letters, @, and _, in
- that order. If _\bb_\ba_\bs_\be is less than or equal to 36, lowercase and upper-
- case letters may be used interchangeably to represent numbers between
- 10 and 35.
-
- Operators are evaluated in order of precedence. Sub-expressions in
+ character constants. Constants with a leading 0 are interpreted as oc-
+ tal numbers. A leading 0x or 0X denotes hexadecimal. Otherwise, num-
+ bers take the form [_\bb_\ba_\bs_\be_\b#]n, where the optional _\bb_\ba_\bs_\be is a decimal num-
+ ber between 2 and 64 representing the arithmetic base, and _\bn is a num-
+ ber in that base. If _\bb_\ba_\bs_\be_\b# is omitted, then base 10 is used. When
+ specifying _\bn, if a non-digit is required, the digits greater than 9 are
+ represented by the lowercase letters, the uppercase letters, @, and _,
+ in that order. If _\bb_\ba_\bs_\be is less than or equal to 36, lowercase and up-
+ percase letters may be used interchangeably to represent numbers be-
+ tween 10 and 35.
+
+ Operators are evaluated in order of precedence. Sub-expressions in
parentheses are evaluated first and may override the precedence rules
above.
C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS
Conditional expressions are used by the [\b[[\b[ compound command and the
t\bte\bes\bst\bt and [\b[ builtin commands to test file attributes and perform string
- and arithmetic comparisons. The t\bte\bes\bst\bt and [\b[ commands determine their be-
- havior based on the number of arguments; see the descriptions of those
- commands for any other command-specific actions.
+ and arithmetic comparisons. The t\bte\bes\bst\bt and [\b[ commands determine their
+ behavior based on the number of arguments; see the descriptions of
+ those commands for any other command-specific actions.
Expressions are formed from the following unary or binary primaries.
B\bBa\bas\bsh\bh handles several filenames specially when they are used in expres-
- sions. If the operating system on which b\bba\bas\bsh\bh is running provides these
+ sions. If the operating system on which b\bba\bas\bsh\bh is running provides these
special files, bash will use them; otherwise it will emulate them in-
ternally with this behavior: If any _\bf_\bi_\bl_\be argument to one of the pri-
- maries is of the form _\b/_\bd_\be_\bv_\b/_\bf_\bd_\b/_\bn, then file descriptor _\bn is checked. If
+ maries is of the form _\b/_\bd_\be_\bv_\b/_\bf_\bd_\b/_\bn, then file descriptor _\bn is checked. If
the _\bf_\bi_\bl_\be argument to one of the primaries is one of _\b/_\bd_\be_\bv_\b/_\bs_\bt_\bd_\bi_\bn,
_\b/_\bd_\be_\bv_\b/_\bs_\bt_\bd_\bo_\bu_\bt, or _\b/_\bd_\be_\bv_\b/_\bs_\bt_\bd_\be_\br_\br, file descriptor 0, 1, or 2, respectively,
is checked.
itself.
When used with [\b[[\b[, or when the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, the <\b< and >\b> op-
- erators sort lexicographically using the current locale. When the shell
- is not in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, the t\bte\bes\bst\bt command sorts using ASCII ordering.
+ erators sort lexicographically using the current locale. When the
+ shell is not in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, the t\bte\bes\bst\bt command sorts using ASCII order-
+ ing.
-\b-a\ba _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists.
-\b-L\bL _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists and is a symbolic link.
-\b-N\bN _\bf_\bi_\bl_\be
- True if _\bf_\bi_\bl_\be exists and has been modified since it was last
+ True if _\bf_\bi_\bl_\be exists and has been modified since it was last
read.
-\b-O\bO _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists and is owned by the effective user id.
-\b-S\bS _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists and is a socket.
_\bf_\bi_\bl_\be_\b1 -\b-e\bef\bf _\bf_\bi_\bl_\be_\b2
- True if _\bf_\bi_\bl_\be_\b1 and _\bf_\bi_\bl_\be_\b2 refer to the same device and inode num-
+ True if _\bf_\bi_\bl_\be_\b1 and _\bf_\bi_\bl_\be_\b2 refer to the same device and inode num-
bers.
_\bf_\bi_\bl_\be_\b1 -n\bnt\bt _\bf_\bi_\bl_\be_\b2
- True if _\bf_\bi_\bl_\be_\b1 is newer (according to modification date) than
+ True if _\bf_\bi_\bl_\be_\b1 is newer (according to modification date) than
_\bf_\bi_\bl_\be_\b2, or if _\bf_\bi_\bl_\be_\b1 exists and _\bf_\bi_\bl_\be_\b2 does not.
_\bf_\bi_\bl_\be_\b1 -o\bot\bt _\bf_\bi_\bl_\be_\b2
- True if _\bf_\bi_\bl_\be_\b1 is older than _\bf_\bi_\bl_\be_\b2, or if _\bf_\bi_\bl_\be_\b2 exists and _\bf_\bi_\bl_\be_\b1
+ True if _\bf_\bi_\bl_\be_\b1 is older than _\bf_\bi_\bl_\be_\b2, or if _\bf_\bi_\bl_\be_\b2 exists and _\bf_\bi_\bl_\be_\b1
does not.
-\b-o\bo _\bo_\bp_\bt_\bn_\ba_\bm_\be
- True if the shell option _\bo_\bp_\bt_\bn_\ba_\bm_\be is enabled. See the list of op-
- tions under the description of the -\b-o\bo option to the s\bse\bet\bt builtin
- below.
+ True if the shell option _\bo_\bp_\bt_\bn_\ba_\bm_\be is enabled. See the list of
+ options under the description of the -\b-o\bo option to the s\bse\bet\bt
+ builtin below.
-\b-v\bv _\bv_\ba_\br_\bn_\ba_\bm_\be
- True if the shell variable _\bv_\ba_\br_\bn_\ba_\bm_\be is set (has been assigned a
- value). If _\bv_\ba_\br_\bn_\ba_\bm_\be is an indexed array variable name subscripted
- by _\b@ or _\b*, this returns true if the array has any set elements.
- If _\bv_\ba_\br_\bn_\ba_\bm_\be is an associative array variable name subscripted by
- _\b@ or _\b*, this returns true if an element with that key is set.
+ True if the shell variable _\bv_\ba_\br_\bn_\ba_\bm_\be is set (has been assigned a
+ value). If _\bv_\ba_\br_\bn_\ba_\bm_\be is an indexed array variable name sub-
+ scripted by _\b@ or _\b*, this returns true if the array has any set
+ elements. If _\bv_\ba_\br_\bn_\ba_\bm_\be is an associative array variable name sub-
+ scripted by _\b@ or _\b*, this returns true if an element with that
+ key is set.
-\b-R\bR _\bv_\ba_\br_\bn_\ba_\bm_\be
True if the shell variable _\bv_\ba_\br_\bn_\ba_\bm_\be is set and is a name refer-
ence.
_\bs_\bt_\br_\bi_\bn_\bg_\b1 =\b==\b= _\bs_\bt_\br_\bi_\bn_\bg_\b2
_\bs_\bt_\br_\bi_\bn_\bg_\b1 =\b= _\bs_\bt_\br_\bi_\bn_\bg_\b2
- True if the strings are equal. =\b= should be used with the t\bte\bes\bst\bt
- command for POSIX conformance. When used with the [\b[[\b[ command,
+ True if the strings are equal. =\b= should be used with the t\bte\bes\bst\bt
+ command for POSIX conformance. When used with the [\b[[\b[ command,
this performs pattern matching as described above (C\bCo\bom\bmp\bpo\bou\bun\bnd\bd C\bCo\bom\bm-\b-
m\bma\ban\bnd\bds\bs).
O\bOP\bP is one of -\b-e\beq\bq, -\b-n\bne\be, -\b-l\blt\bt, -\b-l\ble\be, -\b-g\bgt\bt, or -\b-g\bge\be. These arithmetic
binary operators return true if _\ba_\br_\bg_\b1 is equal to, not equal to,
less than, less than or equal to, greater than, or greater than
- or equal to _\ba_\br_\bg_\b2, respectively. _\bA_\br_\bg_\b1 and _\ba_\br_\bg_\b2 may be positive or
- negative integers. When used with the [\b[[\b[ command, _\bA_\br_\bg_\b1 and _\bA_\br_\bg_\b2
- are evaluated as arithmetic expressions (see A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bA-\b-
- T\bTI\bIO\bON\bN above).
+ or equal to _\ba_\br_\bg_\b2, respectively. _\bA_\br_\bg_\b1 and _\ba_\br_\bg_\b2 may be positive
+ or negative integers. When used with the [\b[[\b[ command, _\bA_\br_\bg_\b1 and
+ _\bA_\br_\bg_\b2 are evaluated as arithmetic expressions (see A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC
+ E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN above).
S\bSI\bIM\bMP\bPL\bLE\bE C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN
When a simple command is executed, the shell performs the following ex-
for later processing.
2. The words that are not variable assignments or redirections are
- expanded. If any words remain after expansion, the first word is
- taken to be the name of the command and the remaining words are
- the arguments.
+ expanded. If any words remain after expansion, the first word
+ is taken to be the name of the command and the remaining words
+ are the arguments.
3. Redirections are performed as described above under R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN.
able.
If no command name results, the variable assignments affect the current
- shell environment. In the case of such a command (one that consists
+ shell environment. In the case of such a command (one that consists
only of assignment statements and redirections), assignment statements
- are performed before redirections. Otherwise, the variables are added
+ are performed before redirections. Otherwise, the variables are added
to the environment of the executed command and do not affect the cur-
- rent shell environment. If any of the assignments attempts to assign a
+ rent shell environment. If any of the assignments attempts to assign a
value to a readonly variable, an error occurs, and the command exits
with a non-zero status.
If no command name results, redirections are performed, but do not af-
- fect the current shell environment. A redirection error causes the com-
- mand to exit with a non-zero status.
+ fect the current shell environment. A redirection error causes the
+ command to exit with a non-zero status.
If there is a command name left after expansion, execution proceeds as
- described below. Otherwise, the command exits. If one of the expansions
- contained a command substitution, the exit status of the command is the
- exit status of the last command substitution performed. If there were
- no command substitutions, the command exits with a status of zero.
+ described below. Otherwise, the command exits. If one of the expan-
+ sions contained a command substitution, the exit status of the command
+ is the exit status of the last command substitution performed. If
+ there were no command substitutions, the command exits with a status of
+ zero.
C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN
- After a command has been split into words, if it results in a simple
- command and an optional list of arguments, the shell performs the fol-
+ After a command has been split into words, if it results in a simple
+ command and an optional list of arguments, the shell performs the fol-
lowing actions.
- If the command name contains no slashes, the shell attempts to locate
- it. If there exists a shell function by that name, that function is in-
- voked as described above in F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS. If the name does not match a
- function, the shell searches for it in the list of shell builtins. If a
- match is found, that builtin is invoked.
-
- If the name is neither a shell function nor a builtin, and contains no
- slashes, b\bba\bas\bsh\bh searches each element of the P\bPA\bAT\bTH\bH for a directory con-
- taining an executable file by that name. B\bBa\bas\bsh\bh uses a hash table to re-
- member the full pathnames of executable files (see h\bha\bas\bsh\bh under S\bSH\bHE\bEL\bLL\bL
- B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). A full search of the directories in P\bPA\bAT\bTH\bH is
- performed only if the command is not found in the hash table. If the
+ If the command name contains no slashes, the shell attempts to locate
+ it. If there exists a shell function by that name, that function is
+ invoked as described above in F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS. If the name does not match a
+ function, the shell searches for it in the list of shell builtins. If
+ a match is found, that builtin is invoked.
+
+ If the name is neither a shell function nor a builtin, and contains no
+ slashes, b\bba\bas\bsh\bh searches each element of the P\bPA\bAT\bTH\bH for a directory con-
+ taining an executable file by that name. B\bBa\bas\bsh\bh uses a hash table to re-
+ member the full pathnames of executable files (see h\bha\bas\bsh\bh under S\bSH\bHE\bEL\bLL\bL
+ B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). A full search of the directories in P\bPA\bAT\bTH\bH is
+ performed only if the command is not found in the hash table. If the
search is unsuccessful, the shell searches for a defined shell function
- named c\bco\bom\bmm\bma\ban\bnd\bd_\b_n\bno\bot\bt_\b_f\bfo\bou\bun\bnd\bd_\b_h\bha\ban\bnd\bdl\ble\be. If that function exists, it is invoked
- in a separate execution environment with the original command and the
- original command's arguments as its arguments, and the function's exit
- status becomes the exit status of that subshell. If that function is
+ named c\bco\bom\bmm\bma\ban\bnd\bd_\b_n\bno\bot\bt_\b_f\bfo\bou\bun\bnd\bd_\b_h\bha\ban\bnd\bdl\ble\be. If that function exists, it is invoked
+ in a separate execution environment with the original command and the
+ original command's arguments as its arguments, and the function's exit
+ status becomes the exit status of that subshell. If that function is
not defined, the shell prints an error message and returns an exit sta-
tus of 127.
- If the search is successful, or if the command name contains one or
+ If the search is successful, or if the command name contains one or
more slashes, the shell executes the named program in a separate execu-
- tion environment. Argument 0 is set to the name given, and the remain-
+ tion environment. Argument 0 is set to the name given, and the remain-
ing arguments to the command are set to the arguments given, if any.
- If this execution fails because the file is not in executable format,
- and the file is not a directory, it is assumed to be a _\bs_\bh_\be_\bl_\bl _\bs_\bc_\br_\bi_\bp_\bt, a
+ If this execution fails because the file is not in executable format,
+ and the file is not a directory, it is assumed to be a _\bs_\bh_\be_\bl_\bl _\bs_\bc_\br_\bi_\bp_\bt, a
file containing shell commands, and the shell creates a new instance of
- itself to execute it. This subshell reinitializes itself, so that the
+ itself to execute it. This subshell reinitializes itself, so that the
effect is as if a new shell had been invoked to handle the script, with
- the exception that the locations of commands remembered by the parent
- (see h\bha\bas\bsh\bh below under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS) are retained by the
+ the exception that the locations of commands remembered by the parent
+ (see h\bha\bas\bsh\bh below under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS) are retained by the
child.
- If the program is a file beginning with #\b#!\b!, the remainder of the first
- line specifies an interpreter for the program. The shell executes the
+ If the program is a file beginning with #\b#!\b!, the remainder of the first
+ line specifies an interpreter for the program. The shell executes the
specified interpreter on operating systems that do not handle this exe-
- cutable format themselves. The arguments to the interpreter consist of
- a single optional argument following the interpreter name on the first
- line of the program, followed by the name of the program, followed by
+ cutable format themselves. The arguments to the interpreter consist of
+ a single optional argument following the interpreter name on the first
+ line of the program, followed by the name of the program, followed by
the command arguments, if any.
C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT
- The shell has an _\be_\bx_\be_\bc_\bu_\bt_\bi_\bo_\bn _\be_\bn_\bv_\bi_\br_\bo_\bn_\bm_\be_\bn_\bt, which consists of the follow-
+ The shell has an _\be_\bx_\be_\bc_\bu_\bt_\bi_\bo_\bn _\be_\bn_\bv_\bi_\br_\bo_\bn_\bm_\be_\bn_\bt, which consists of the follow-
ing:
- +\bo open files inherited by the shell at invocation, as modified by
+ +\bo open files inherited by the shell at invocation, as modified by
redirections supplied to the e\bex\bxe\bec\bc builtin
- +\bo the current working directory as set by c\bcd\bd, p\bpu\bus\bsh\bhd\bd, or p\bpo\bop\bpd\bd, or
+ +\bo the current working directory as set by c\bcd\bd, p\bpu\bus\bsh\bhd\bd, or p\bpo\bop\bpd\bd, or
inherited by the shell at invocation
- +\bo the file creation mode mask as set by u\bum\bma\bas\bsk\bk or inherited from
+ +\bo the file creation mode mask as set by u\bum\bma\bas\bsk\bk or inherited from
the shell's parent
+\bo current traps set by t\btr\bra\bap\bp
+\bo shell parameters that are set by variable assignment or with s\bse\bet\bt
or inherited from the shell's parent in the environment
- +\bo shell functions defined during execution or inherited from the
+ +\bo shell functions defined during execution or inherited from the
shell's parent in the environment
- +\bo options enabled at invocation (either by default or with com-
+ +\bo options enabled at invocation (either by default or with com-
mand-line arguments) or by s\bse\bet\bt
+\bo options enabled by s\bsh\bho\bop\bpt\bt
+\bo shell aliases defined with a\bal\bli\bia\bas\bs
- +\bo various process IDs, including those of background jobs, the
+ +\bo various process IDs, including those of background jobs, the
value of $\b$$\b$, and the value of P\bPP\bPI\bID\bD
- When a simple command other than a builtin or shell function is to be
- executed, it is invoked in a separate execution environment that con-
- sists of the following. Unless otherwise noted, the values are inher-
+ When a simple command other than a builtin or shell function is to be
+ executed, it is invoked in a separate execution environment that con-
+ sists of the following. Unless otherwise noted, the values are inher-
ited from the shell.
- +\bo the shell's open files, plus any modifications and additions
+ +\bo the shell's open files, plus any modifications and additions
specified by redirections to the command
+\bo the current working directory
+\bo the file creation mode mask
- +\bo shell variables and functions marked for export, along with
+ +\bo shell variables and functions marked for export, along with
variables exported for the command, passed in the environment
+\bo traps caught by the shell are reset to the values inherited from
the shell's parent, and traps ignored by the shell are ignored
- A command invoked in this separate environment cannot affect the
+ A command invoked in this separate environment cannot affect the
shell's execution environment.
A _\bs_\bu_\bb_\bs_\bh_\be_\bl_\bl is a copy of the shell process.
- Command substitution, commands grouped with parentheses, and asynchro-
+ Command substitution, commands grouped with parentheses, and asynchro-
nous commands are invoked in a subshell environment that is a duplicate
of the shell environment, except that traps caught by the shell are re-
- set to the values that the shell inherited from its parent at invoca-
- tion. Builtin commands that are invoked as part of a pipeline are also
- executed in a subshell environment. Changes made to the subshell envi-
+ set to the values that the shell inherited from its parent at invoca-
+ tion. Builtin commands that are invoked as part of a pipeline are also
+ executed in a subshell environment. Changes made to the subshell envi-
ronment cannot affect the shell's execution environment.
Subshells spawned to execute command substitutions inherit the value of
- the -\b-e\be option from the parent shell. When not in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, b\bba\bas\bsh\bh
+ the -\b-e\be option from the parent shell. When not in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, b\bba\bas\bsh\bh
clears the -\b-e\be option in such subshells.
- If a command is followed by a &\b& and job control is not active, the de-
- fault standard input for the command is the empty file _\b/_\bd_\be_\bv_\b/_\bn_\bu_\bl_\bl. Oth-
- erwise, the invoked command inherits the file descriptors of the call-
+ If a command is followed by a &\b& and job control is not active, the de-
+ fault standard input for the command is the empty file _\b/_\bd_\be_\bv_\b/_\bn_\bu_\bl_\bl. Oth-
+ erwise, the invoked command inherits the file descriptors of the call-
ing shell as modified by redirections.
E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT
- When a program is invoked it is given an array of strings called the
- _\be_\bn_\bv_\bi_\br_\bo_\bn_\bm_\be_\bn_\bt. This is a list of _\bn_\ba_\bm_\be-_\bv_\ba_\bl_\bu_\be pairs, of the form
+ When a program is invoked it is given an array of strings called the
+ _\be_\bn_\bv_\bi_\br_\bo_\bn_\bm_\be_\bn_\bt. This is a list of _\bn_\ba_\bm_\be-_\bv_\ba_\bl_\bu_\be pairs, of the form
_\bn_\ba_\bm_\be=_\bv_\ba_\bl_\bu_\be.
- The shell provides several ways to manipulate the environment. On invo-
- cation, the shell scans its own environment and creates a parameter for
- each name found, automatically marking it for _\be_\bx_\bp_\bo_\br_\bt to child pro-
- cesses. Executed commands inherit the environment. The e\bex\bxp\bpo\bor\brt\bt and d\bde\be-\b-
- c\bcl\bla\bar\bre\be -\b-x\bx commands allow parameters and functions to be added to and
- deleted from the environment. If the value of a parameter in the envi-
+ The shell provides several ways to manipulate the environment. On in-
+ vocation, the shell scans its own environment and creates a parameter
+ for each name found, automatically marking it for _\be_\bx_\bp_\bo_\br_\bt to child pro-
+ cesses. Executed commands inherit the environment. The e\bex\bxp\bpo\bor\brt\bt and d\bde\be-\b-
+ c\bcl\bla\bar\bre\be -\b-x\bx commands allow parameters and functions to be added to and
+ deleted from the environment. If the value of a parameter in the envi-
ronment is modified, the new value becomes part of the environment, re-
- placing the old. The environment inherited by any executed command con-
- sists of the shell's initial environment, whose values may be modified
- in the shell, less any pairs removed by the u\bun\bns\bse\bet\bt command, plus any ad-
- ditions via the e\bex\bxp\bpo\bor\brt\bt and d\bde\bec\bcl\bla\bar\bre\be -\b-x\bx commands.
-
- The environment for any _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd or function may be augmented
- temporarily by prefixing it with parameter assignments, as described
- above in P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS. These assignment statements affect only the envi-
+ placing the old. The environment inherited by any executed command
+ consists of the shell's initial environment, whose values may be modi-
+ fied in the shell, less any pairs removed by the u\bun\bns\bse\bet\bt command, plus
+ any additions via the e\bex\bxp\bpo\bor\brt\bt and d\bde\bec\bcl\bla\bar\bre\be -\b-x\bx commands.
+
+ The environment for any _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd or function may be augmented
+ temporarily by prefixing it with parameter assignments, as described
+ above in P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS. These assignment statements affect only the envi-
ronment seen by that command.
- If the -\b-k\bk option is set (see the s\bse\bet\bt builtin command below), then _\ba_\bl_\bl
- parameter assignments are placed in the environment for a command, not
+ If the -\b-k\bk option is set (see the s\bse\bet\bt builtin command below), then _\ba_\bl_\bl
+ parameter assignments are placed in the environment for a command, not
just those that precede the command name.
- When b\bba\bas\bsh\bh invokes an external command, the variable _\b_ is set to the
+ When b\bba\bas\bsh\bh invokes an external command, the variable _\b_ is set to the
full filename of the command and passed to that command in its environ-
ment.
E\bEX\bXI\bIT\bT S\bST\bTA\bAT\bTU\bUS\bS
- The exit status of an executed command is the value returned by the
- _\bw_\ba_\bi_\bt_\bp_\bi_\bd system call or equivalent function. Exit statuses fall between
- 0 and 255, though, as explained below, the shell may use values above
- 125 specially. Exit statuses from shell builtins and compound commands
- are also limited to this range. Under certain circumstances, the shell
+ The exit status of an executed command is the value returned by the
+ _\bw_\ba_\bi_\bt_\bp_\bi_\bd system call or equivalent function. Exit statuses fall between
+ 0 and 255, though, as explained below, the shell may use values above
+ 125 specially. Exit statuses from shell builtins and compound commands
+ are also limited to this range. Under certain circumstances, the shell
will use special values to indicate specific failure modes.
For the shell's purposes, a command which exits with a zero exit status
- has succeeded. An exit status of zero indicates success. A non-zero
- exit status indicates failure. When a command terminates on a fatal
+ has succeeded. An exit status of zero indicates success. A non-zero
+ exit status indicates failure. When a command terminates on a fatal
signal _\bN, b\bba\bas\bsh\bh uses the value of 128+_\bN as the exit status.
- If a command is not found, the child process created to execute it re-
- turns a status of 127. If a command is found but is not executable, the
- return status is 126.
+ If a command is not found, the child process created to execute it re-
+ turns a status of 127. If a command is found but is not executable,
+ the return status is 126.
If a command fails because of an error during expansion or redirection,
the exit status is greater than zero.
- Shell builtin commands return a status of 0 (_\bt_\br_\bu_\be) if successful, and
- non-zero (_\bf_\ba_\bl_\bs_\be) if an error occurs while they execute. All builtins
- return an exit status of 2 to indicate incorrect usage, generally in-
+ Shell builtin commands return a status of 0 (_\bt_\br_\bu_\be) if successful, and
+ non-zero (_\bf_\ba_\bl_\bs_\be) if an error occurs while they execute. All builtins
+ return an exit status of 2 to indicate incorrect usage, generally in-
valid options or missing arguments.
The exit status of the last command is available in the special parame-
ter $?.
- B\bBa\bas\bsh\bh itself returns the exit status of the last command executed, un-
- less a syntax error occurs, in which case it exits with a non-zero
- value. See also the e\bex\bxi\bit\bt builtin command below.
+ B\bBa\bas\bsh\bh itself returns the exit status of the last command executed, un-
+ less a syntax error occurs, in which case it exits with a non-zero
+ value. See also the e\bex\bxi\bit\bt builtin command below.
S\bSI\bIG\bGN\bNA\bAL\bLS\bS
- When b\bba\bas\bsh\bh is interactive, in the absence of any traps, it ignores
+ When b\bba\bas\bsh\bh is interactive, in the absence of any traps, it ignores
S\bSI\bIG\bGT\bTE\bER\bRM\bM (so that k\bki\bil\bll\bl 0\b0 does not kill an interactive shell), and S\bSI\bIG\bGI\bIN\bNT\bT
- is caught and handled (so that the w\bwa\bai\bit\bt builtin is interruptible). In
- all cases, b\bba\bas\bsh\bh ignores S\bSI\bIG\bGQ\bQU\bUI\bIT\bT. If job control is in effect, b\bba\bas\bsh\bh ig-
+ is caught and handled (so that the w\bwa\bai\bit\bt builtin is interruptible). In
+ all cases, b\bba\bas\bsh\bh ignores S\bSI\bIG\bGQ\bQU\bUI\bIT\bT. If job control is in effect, b\bba\bas\bsh\bh ig-
nores S\bSI\bIG\bGT\bTT\bTI\bIN\bN, S\bSI\bIG\bGT\bTT\bTO\bOU\bU, and S\bSI\bIG\bGT\bTS\bST\bTP\bP.
Non-builtin commands run by b\bba\bas\bsh\bh have signal handlers set to the values
- inherited by the shell from its parent. When job control is not in ef-
- fect, asynchronous commands ignore S\bSI\bIG\bGI\bIN\bNT\bT and S\bSI\bIG\bGQ\bQU\bUI\bIT\bT in addition to
- these inherited handlers. Commands run as a result of command substitu-
- tion ignore the keyboard-generated job control signals S\bSI\bIG\bGT\bTT\bTI\bIN\bN, S\bSI\bIG\bGT\bT-\b-
+ inherited by the shell from its parent. When job control is not in ef-
+ fect, asynchronous commands ignore S\bSI\bIG\bGI\bIN\bNT\bT and S\bSI\bIG\bGQ\bQU\bUI\bIT\bT in addition to
+ these inherited handlers. Commands run as a result of command substi-
+ tution ignore the keyboard-generated job control signals S\bSI\bIG\bGT\bTT\bTI\bIN\bN, S\bSI\bIG\bGT\bT-\b-
T\bTO\bOU\bU, and S\bSI\bIG\bGT\bTS\bST\bTP\bP.
- The shell exits by default upon receipt of a S\bSI\bIG\bGH\bHU\bUP\bP. Before exiting, an
- interactive shell resends the S\bSI\bIG\bGH\bHU\bUP\bP to all jobs, running or stopped.
- Stopped jobs are sent S\bSI\bIG\bGC\bCO\bON\bNT\bT to ensure that they receive the S\bSI\bIG\bGH\bHU\bUP\bP.
- To prevent the shell from sending the signal to a particular job, it
- should be removed from the jobs table with the d\bdi\bis\bso\bow\bwn\bn builtin (see
- S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below) or marked to not receive S\bSI\bIG\bGH\bHU\bUP\bP using
- d\bdi\bis\bso\bow\bwn\bn -\b-h\bh.
+ The shell exits by default upon receipt of a S\bSI\bIG\bGH\bHU\bUP\bP. Before exiting,
+ an interactive shell resends the S\bSI\bIG\bGH\bHU\bUP\bP to all jobs, running or
+ stopped. Stopped jobs are sent S\bSI\bIG\bGC\bCO\bON\bNT\bT to ensure that they receive the
+ S\bSI\bIG\bGH\bHU\bUP\bP. To prevent the shell from sending the signal to a particular
+ job, it should be removed from the jobs table with the d\bdi\bis\bso\bow\bwn\bn builtin
+ (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below) or marked to not receive S\bSI\bIG\bGH\bHU\bUP\bP us-
+ ing d\bdi\bis\bso\bow\bwn\bn -\b-h\bh.
- If the h\bhu\bup\bpo\bon\bne\bex\bxi\bit\bt shell option has been set with s\bsh\bho\bop\bpt\bt, b\bba\bas\bsh\bh sends a
+ If the h\bhu\bup\bpo\bon\bne\bex\bxi\bit\bt shell option has been set with s\bsh\bho\bop\bpt\bt, b\bba\bas\bsh\bh sends a
S\bSI\bIG\bGH\bHU\bUP\bP to all jobs when an interactive login shell exits.
- If b\bba\bas\bsh\bh is waiting for a command to complete and receives a signal for
+ If b\bba\bas\bsh\bh is waiting for a command to complete and receives a signal for
which a trap has been set, the trap will not be executed until the com-
- mand completes. When b\bba\bas\bsh\bh is waiting for an asynchronous command via
- the w\bwa\bai\bit\bt builtin, the reception of a signal for which a trap has been
+ mand completes. When b\bba\bas\bsh\bh is waiting for an asynchronous command via
+ the w\bwa\bai\bit\bt builtin, the reception of a signal for which a trap has been
set will cause the w\bwa\bai\bit\bt builtin to return immediately with an exit sta-
tus greater than 128, immediately after which the trap is executed.
- When job control is not enabled, and b\bba\bas\bsh\bh is waiting for a foreground
+ When job control is not enabled, and b\bba\bas\bsh\bh is waiting for a foreground
command to complete, the shell receives keyboard-generated signals such
- as S\bSI\bIG\bGI\bIN\bNT\bT (usually generated by ^\b^C\bC) that users commonly intend to send
- to that command. This happens because the shell and the command are in
+ as S\bSI\bIG\bGI\bIN\bNT\bT (usually generated by ^\b^C\bC) that users commonly intend to send
+ to that command. This happens because the shell and the command are in
the same process group as the terminal, and ^\b^C\bC sends S\bSI\bIG\bGI\bIN\bNT\bT to all pro-
cesses in that process group.
- When b\bba\bas\bsh\bh is running without job control enabled and receives S\bSI\bIG\bGI\bIN\bNT\bT
- while waiting for a foreground command, it waits until that foreground
+ When b\bba\bas\bsh\bh is running without job control enabled and receives S\bSI\bIG\bGI\bIN\bNT\bT
+ while waiting for a foreground command, it waits until that foreground
command terminates and then decides what to do about the S\bSI\bIG\bGI\bIN\bNT\bT:
1. If the command terminates due to the S\bSI\bIG\bGI\bIN\bNT\bT, b\bba\bas\bsh\bh concludes that
- the user meant to end the entire script, and acts on the S\bSI\bIG\bGI\bIN\bNT\bT
+ the user meant to end the entire script, and acts on the S\bSI\bIG\bGI\bIN\bNT\bT
(e.g., by running a S\bSI\bIG\bGI\bIN\bNT\bT trap or exiting itself);
- 2. If the command does not terminate due to S\bSI\bIG\bGI\bIN\bNT\bT, the program
- handled the S\bSI\bIG\bGI\bIN\bNT\bT itself and did not treat it as a fatal sig-
- nal. In that case, b\bba\bas\bsh\bh does not treat S\bSI\bIG\bGI\bIN\bNT\bT as a fatal signal,
- either, instead assuming that the S\bSI\bIG\bGI\bIN\bNT\bT was used as part of the
- program's normal operation (e.g., emacs uses it to abort editing
- commands) or deliberately discarded. However, b\bba\bas\bsh\bh will run any
- trap set on S\bSI\bIG\bGI\bIN\bNT\bT, as it does with any other trapped signal it
- receives while it is waiting for the foreground command to com-
- plete, for compatibility.
+ 2. If the command does not terminate due to S\bSI\bIG\bGI\bIN\bNT\bT, the program
+ handled the S\bSI\bIG\bGI\bIN\bNT\bT itself and did not treat it as a fatal sig-
+ nal. In that case, b\bba\bas\bsh\bh does not treat S\bSI\bIG\bGI\bIN\bNT\bT as a fatal sig-
+ nal, either, instead assuming that the S\bSI\bIG\bGI\bIN\bNT\bT was used as part
+ of the program's normal operation (e.g., emacs uses it to abort
+ editing commands) or deliberately discarded. However, b\bba\bas\bsh\bh will
+ run any trap set on S\bSI\bIG\bGI\bIN\bNT\bT, as it does with any other trapped
+ signal it receives while it is waiting for the foreground com-
+ mand to complete, for compatibility.
J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL
_\bJ_\bo_\bb _\bc_\bo_\bn_\bt_\br_\bo_\bl refers to the ability to selectively stop (_\bs_\bu_\bs_\bp_\be_\bn_\bd) the ex-
- ecution of processes and continue (_\br_\be_\bs_\bu_\bm_\be) their execution at a later
- point. A user typically employs this facility via an interactive inter-
- face supplied jointly by the operating system kernel's terminal driver
- and b\bba\bas\bsh\bh.
+ ecution of processes and continue (_\br_\be_\bs_\bu_\bm_\be) their execution at a later
+ point. A user typically employs this facility via an interactive in-
+ terface supplied jointly by the operating system kernel's terminal
+ driver and b\bba\bas\bsh\bh.
- The shell associates a _\bj_\bo_\bb with each pipeline. It keeps a table of cur-
- rently executing jobs, which may be listed with the j\bjo\bob\bbs\bs command. When
- b\bba\bas\bsh\bh starts a job asynchronously (in the _\bb_\ba_\bc_\bk_\bg_\br_\bo_\bu_\bn_\bd), it prints a line
- that looks like:
+ The shell associates a _\bj_\bo_\bb with each pipeline. It keeps a table of
+ currently executing jobs, which may be listed with the j\bjo\bob\bbs\bs command.
+ When b\bba\bas\bsh\bh starts a job asynchronously (in the _\bb_\ba_\bc_\bk_\bg_\br_\bo_\bu_\bn_\bd), it prints a
+ line that looks like:
[1] 25647
indicating that this job is job number 1 and that the process ID of the
- last process in the pipeline associated with this job is 25647. All of
- the processes in a single pipeline are members of the same job. B\bBa\bas\bsh\bh
+ last process in the pipeline associated with this job is 25647. All of
+ the processes in a single pipeline are members of the same job. B\bBa\bas\bsh\bh
uses the _\bj_\bo_\bb abstraction as the basis for job control.
- To facilitate the implementation of the user interface to job control,
+ To facilitate the implementation of the user interface to job control,
the operating system maintains the notion of a _\bc_\bu_\br_\br_\be_\bn_\bt _\bt_\be_\br_\bm_\bi_\bn_\ba_\bl _\bp_\br_\bo_\bc_\be_\bs_\bs
- _\bg_\br_\bo_\bu_\bp _\bI_\bD. Members of this process group (processes whose process group
+ _\bg_\br_\bo_\bu_\bp _\bI_\bD. Members of this process group (processes whose process group
ID is equal to the current terminal process group ID) receive keyboard-
- generated signals such as S\bSI\bIG\bGI\bIN\bNT\bT. These processes are said to be in the
- _\bf_\bo_\br_\be_\bg_\br_\bo_\bu_\bn_\bd. _\bB_\ba_\bc_\bk_\bg_\br_\bo_\bu_\bn_\bd processes are those whose process group ID dif-
- fers from the terminal's; such processes are immune to keyboard-gener-
- ated signals. Only foreground processes are allowed to read from or, if
- the user so specifies with stty tostop, write to the terminal. Back-
- ground processes which attempt to read from (write to when stty tostop
- is in effect) the terminal are sent a S\bSI\bIG\bGT\bTT\bTI\bIN\bN (\b(S\bSI\bIG\bGT\bTT\bTO\bOU\bU)\b) signal by the
- kernel's terminal driver, which, unless caught, suspends the process.
+ generated signals such as S\bSI\bIG\bGI\bIN\bNT\bT. These processes are said to be in
+ the _\bf_\bo_\br_\be_\bg_\br_\bo_\bu_\bn_\bd. _\bB_\ba_\bc_\bk_\bg_\br_\bo_\bu_\bn_\bd processes are those whose process group ID
+ differs from the terminal's; such processes are immune to keyboard-gen-
+ erated signals. Only foreground processes are allowed to read from or,
+ if the user so specifies with stty tostop, write to the terminal.
+ Background processes which attempt to read from (write to when stty
+ tostop is in effect) the terminal are sent a S\bSI\bIG\bGT\bTT\bTI\bIN\bN (\b(S\bSI\bIG\bGT\bTT\bTO\bOU\bU)\b) signal
+ by the kernel's terminal driver, which, unless caught, suspends the
+ process.
If the operating system on which b\bba\bas\bsh\bh is running supports job control,
- b\bba\bas\bsh\bh contains facilities to use it. Typing the _\bs_\bu_\bs_\bp_\be_\bn_\bd character (typi-
- cally ^\b^Z\bZ, Control-Z) while a process is running causes that process to
- be stopped and returns control to b\bba\bas\bsh\bh. Typing the _\bd_\be_\bl_\ba_\by_\be_\bd _\bs_\bu_\bs_\bp_\be_\bn_\bd
+ b\bba\bas\bsh\bh contains facilities to use it. Typing the _\bs_\bu_\bs_\bp_\be_\bn_\bd character (typ-
+ ically ^\b^Z\bZ, Control-Z) while a process is running causes that process to
+ be stopped and returns control to b\bba\bas\bsh\bh. Typing the _\bd_\be_\bl_\ba_\by_\be_\bd _\bs_\bu_\bs_\bp_\be_\bn_\bd
character (typically ^\b^Y\bY, Control-Y) causes the process to be stopped
when it attempts to read input from the terminal, and control to be re-
- turned to b\bba\bas\bsh\bh. The user may then manipulate the state of this job, us-
- ing the b\bbg\bg command to continue it in the background, the f\bfg\bg command to
- continue it in the foreground, or the k\bki\bil\bll\bl command to kill it. A ^\b^Z\bZ
+ turned to b\bba\bas\bsh\bh. The user may then manipulate the state of this job,
+ using the b\bbg\bg command to continue it in the background, the f\bfg\bg command
+ to continue it in the foreground, or the k\bki\bil\bll\bl command to kill it. A ^\b^Z\bZ
takes effect immediately, and has the additional side effect of causing
pending output and typeahead to be discarded.
- There are a number of ways to refer to a job in the shell. The charac-
- ter %\b% introduces a job specification (_\bj_\bo_\bb_\bs_\bp_\be_\bc). Job number _\bn may be re-
- ferred to as %\b%n\bn. A job may also be referred to using a prefix of the
+ There are a number of ways to refer to a job in the shell. The charac-
+ ter %\b% introduces a job specification (_\bj_\bo_\bb_\bs_\bp_\be_\bc). Job number _\bn may be
+ referred to as %\b%n\bn. A job may also be referred to using a prefix of the
name used to start it, or using a substring that appears in its command
- line. For example, %\b%c\bce\be refers to a stopped job whose command name be-
+ line. For example, %\b%c\bce\be refers to a stopped job whose command name be-
gins with c\bce\be. If a prefix matches more than one job, b\bba\bas\bsh\bh reports an
- error. Using %\b%?\b?c\bce\be, on the other hand, refers to any job containing the
- string c\bce\be in its command line. If the substring matches more than one
- job, b\bba\bas\bsh\bh reports an error. The symbols %\b%%\b% and %\b%+\b+ refer to the shell's
+ error. Using %\b%?\b?c\bce\be, on the other hand, refers to any job containing the
+ string c\bce\be in its command line. If the substring matches more than one
+ job, b\bba\bas\bsh\bh reports an error. The symbols %\b%%\b% and %\b%+\b+ refer to the shell's
notion of the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb, which is the last job stopped while it was
- in the foreground or started in the background. The _\bp_\br_\be_\bv_\bi_\bo_\bu_\bs _\bj_\bo_\bb may be
- referenced using %\b%-\b-. If there is only a single job, %\b%+\b+ and %\b%-\b- can both
- be used to refer to that job. In output pertaining to jobs (e.g., the
- output of the j\bjo\bob\bbs\bs command), the current job is always flagged with a
- +\b+, and the previous job with a -\b-. A single % (with no accompanying job
- specification) also refers to the current job.
+ in the foreground or started in the background. The _\bp_\br_\be_\bv_\bi_\bo_\bu_\bs _\bj_\bo_\bb may
+ be referenced using %\b%-\b-. If there is only a single job, %\b%+\b+ and %\b%-\b- can
+ both be used to refer to that job. In output pertaining to jobs (e.g.,
+ the output of the j\bjo\bob\bbs\bs command), the current job is always flagged with
+ a +\b+, and the previous job with a -\b-. A single % (with no accompanying
+ job specification) also refers to the current job.
Simply naming a job can be used to bring it into the foreground: %\b%1\b1 is
a synonym for `\b``\b`f\bfg\bg %\b%1\b1'\b''\b', bringing job 1 from the background into the
- foreground. Similarly, `\b``\b`%\b%1\b1 &\b&'\b''\b' resumes job 1 in the background, equiv-
- alent to `\b``\b`b\bbg\bg %\b%1\b1'\b''\b'.
+ foreground. Similarly, `\b``\b`%\b%1\b1 &\b&'\b''\b' resumes job 1 in the background,
+ equivalent to `\b``\b`b\bbg\bg %\b%1\b1'\b''\b'.
- The shell learns immediately whenever a job changes state. Normally,
+ The shell learns immediately whenever a job changes state. Normally,
b\bba\bas\bsh\bh waits until it is about to print a prompt before reporting changes
in a job's status so as to not interrupt any other output. If the -\b-b\bb
option to the s\bse\bet\bt builtin command is enabled, b\bba\bas\bsh\bh reports such changes
- immediately. Any trap on S\bSI\bIG\bGC\bCH\bHL\bLD\bD is executed for each child that exits.
+ immediately. Any trap on S\bSI\bIG\bGC\bCH\bHL\bLD\bD is executed for each child that ex-
+ its.
- If an attempt to exit b\bba\bas\bsh\bh is made while jobs are stopped (or, if the
- c\bch\bhe\bec\bck\bkj\bjo\bob\bbs\bs shell option has been enabled using the s\bsh\bho\bop\bpt\bt builtin, run-
+ If an attempt to exit b\bba\bas\bsh\bh is made while jobs are stopped (or, if the
+ c\bch\bhe\bec\bck\bkj\bjo\bob\bbs\bs shell option has been enabled using the s\bsh\bho\bop\bpt\bt builtin, run-
ning), the shell prints a warning message, and, if the c\bch\bhe\bec\bck\bkj\bjo\bob\bbs\bs option
- is enabled, lists the jobs and their statuses. The j\bjo\bob\bbs\bs command may
- then be used to inspect their status. If a second attempt to exit is
- made without an intervening command, the shell does not print another
+ is enabled, lists the jobs and their statuses. The j\bjo\bob\bbs\bs command may
+ then be used to inspect their status. If a second attempt to exit is
+ made without an intervening command, the shell does not print another
warning, and any stopped jobs are terminated.
- When the shell is waiting for a job or process using the w\bwa\bai\bit\bt builtin,
- and job control is enabled, w\bwa\bai\bit\bt will return when the job changes
- state. The -\b-f\bf option causes w\bwa\bai\bit\bt to wait until the job or process ter-
+ When the shell is waiting for a job or process using the w\bwa\bai\bit\bt builtin,
+ and job control is enabled, w\bwa\bai\bit\bt will return when the job changes
+ state. The -\b-f\bf option causes w\bwa\bai\bit\bt to wait until the job or process ter-
minates before returning.
P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG
When executing interactively, b\bba\bas\bsh\bh displays the primary prompt P\bPS\bS1\b1 when
- it is ready to read a command, and the secondary prompt P\bPS\bS2\b2 when it
- needs more input to complete a command. B\bBa\bas\bsh\bh displays P\bPS\bS0\b0 after it
- reads a command but before executing it. B\bBa\bas\bsh\bh displays P\bPS\bS4\b4 as described
- above before tracing each command when the -\b-x\bx option is enabled. B\bBa\bas\bsh\bh
- allows these prompt strings to be customized by inserting a number of
- backslash-escaped special characters that are decoded as follows:
+ it is ready to read a command, and the secondary prompt P\bPS\bS2\b2 when it
+ needs more input to complete a command. B\bBa\bas\bsh\bh displays P\bPS\bS0\b0 after it
+ reads a command but before executing it. B\bBa\bas\bsh\bh displays P\bPS\bS4\b4 as de-
+ scribed above before tracing each command when the -\b-x\bx option is en-
+ abled. B\bBa\bas\bsh\bh allows these prompt strings to be customized by inserting
+ a number of backslash-escaped special characters that are decoded as
+ follows:
\\b\a\ba an ASCII bell character (07)
\\b\d\bd the date in "Weekday Month Date" format (e.g., "Tue May
26")
\\b\D\bD{\b{_\bf_\bo_\br_\bm_\ba_\bt}\b}
the _\bf_\bo_\br_\bm_\ba_\bt is passed to _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3) and the result is in-
serted into the prompt string; an empty _\bf_\bo_\br_\bm_\ba_\bt results in
- a locale-specific time representation. The braces are re-
- quired
+ a locale-specific time representation. The braces are
+ required
\\b\e\be an ASCII escape character (033)
\\b\h\bh the hostname up to the first `.'
\\b\H\bH the hostname
history number of a command is its position in the history list, which
may include commands restored from the history file (see H\bHI\bIS\bST\bTO\bOR\bRY\bY be-
low), while the command number is the position in the sequence of com-
- mands executed during the current shell session. After the string is
+ mands executed during the current shell session. After the string is
decoded, it is expanded via parameter expansion, command substitution,
arithmetic expansion, and quote removal, subject to the value of the
p\bpr\bro\bom\bmp\bpt\btv\bva\bar\brs\bs shell option (see the description of the s\bsh\bho\bop\bpt\bt command under
- S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). This can have unwanted side effects if
+ S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). This can have unwanted side effects if
escaped portions of the string appear within command substitution or
contain characters special to word expansion.
This is the library that handles reading input when using an interac-
tive shell, unless the -\b--\b-n\bno\boe\bed\bdi\bit\bti\bin\bng\bg option is given at shell invocation.
Line editing is also used when using the -\b-e\be option to the r\bre\bea\bad\bd builtin.
- By default, the line editing commands are similar to those of Emacs. A
- vi-style line editing interface is also available. Line editing can be
+ By default, the line editing commands are similar to those of Emacs. A
+ vi-style line editing interface is also available. Line editing can be
enabled at any time using the -\b-o\bo e\bem\bma\bac\bcs\bs or -\b-o\bo v\bvi\bi options to the s\bse\bet\bt
- builtin (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). To turn off line editing
+ builtin (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). To turn off line editing
after the shell is running, use the +\b+o\bo e\bem\bma\bac\bcs\bs or +\b+o\bo v\bvi\bi options to the
s\bse\bet\bt builtin.
R\bRe\bea\bad\bdl\bli\bin\bne\be N\bNo\bot\bta\bat\bti\bio\bon\bn
In this section, the Emacs-style notation is used to denote keystrokes.
- Control keys are denoted by C-_\bk_\be_\by, e.g., C-n means Control-N. Simi-
- larly, _\bm_\be_\bt_\ba keys are denoted by M-_\bk_\be_\by, so M-x means Meta-X. (On key-
+ Control keys are denoted by C-_\bk_\be_\by, e.g., C-n means Control-N. Simi-
+ larly, _\bm_\be_\bt_\ba keys are denoted by M-_\bk_\be_\by, so M-x means Meta-X. (On key-
boards without a _\bm_\be_\bt_\ba key, M-_\bx means ESC _\bx, i.e., press the Escape key
- then the _\bx key. This makes ESC the _\bm_\be_\bt_\ba _\bp_\br_\be_\bf_\bi_\bx. The combination M-C-_\bx
+ then the _\bx key. This makes ESC the _\bm_\be_\bt_\ba _\bp_\br_\be_\bf_\bi_\bx. The combination M-C-_\bx
means ESC-Control-_\bx, or press the Escape key then hold the Control key
while pressing the _\bx key.)
Readline commands may be given numeric _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs, which normally act as
- a repeat count. Sometimes, however, it is the sign of the argument that
- is significant. Passing a negative argument to a command that acts in
- the forward direction (e.g., k\bki\bil\bll\bl-\b-l\bli\bin\bne\be) causes that command to act in a
- backward direction. Commands whose behavior with arguments deviates
- from this are noted below.
+ a repeat count. Sometimes, however, it is the sign of the argument
+ that is significant. Passing a negative argument to a command that
+ acts in the forward direction (e.g., k\bki\bil\bll\bl-\b-l\bli\bin\bne\be) causes that command to
+ act in a backward direction. Commands whose behavior with arguments
+ deviates from this are noted below.
When a command is described as _\bk_\bi_\bl_\bl_\bi_\bn_\bg text, the text deleted is saved
- for possible future retrieval (_\by_\ba_\bn_\bk_\bi_\bn_\bg). The killed text is saved in a
- _\bk_\bi_\bl_\bl _\br_\bi_\bn_\bg. Consecutive kills cause the text to be accumulated into one
- unit, which can be yanked all at once. Commands which do not kill text
+ for possible future retrieval (_\by_\ba_\bn_\bk_\bi_\bn_\bg). The killed text is saved in a
+ _\bk_\bi_\bl_\bl _\br_\bi_\bn_\bg. Consecutive kills cause the text to be accumulated into one
+ unit, which can be yanked all at once. Commands which do not kill text
separate the chunks of text on the kill ring.
R\bRe\bea\bad\bdl\bli\bin\bne\be I\bIn\bni\bit\bti\bia\bal\bli\biz\bza\bat\bti\bio\bon\bn
Readline is customized by putting commands in an initialization file
- (the _\bi_\bn_\bp_\bu_\bt_\br_\bc file). The name of this file is taken from the value of
- the I\bIN\bNP\bPU\bUT\bTR\bRC\bC variable. If that variable is unset, the default is _\b~_\b/_\b._\bi_\bn_\b-
- _\bp_\bu_\bt_\br_\bc. If that file does not exist or cannot be read, the ultimate de-
- fault is _\b/_\be_\bt_\bc_\b/_\bi_\bn_\bp_\bu_\bt_\br_\bc. When a program which uses the readline library
- starts up, the initialization file is read, and the key bindings and
- variables are set. There are only a few basic constructs allowed in the
- readline initialization file. Blank lines are ignored. Lines beginning
- with a #\b# are comments. Lines beginning with a $\b$ indicate conditional
- constructs. Other lines denote key bindings and variable settings.
-
- The default key-bindings may be changed with an _\bi_\bn_\bp_\bu_\bt_\br_\bc file. Other
+ (the _\bi_\bn_\bp_\bu_\bt_\br_\bc file). The name of this file is taken from the value of
+ the I\bIN\bNP\bPU\bUT\bTR\bRC\bC variable. If that variable is unset, the default is _\b~_\b/_\b._\bi_\bn_\b-
+ _\bp_\bu_\bt_\br_\bc. If that file does not exist or cannot be read, the ultimate
+ default is _\b/_\be_\bt_\bc_\b/_\bi_\bn_\bp_\bu_\bt_\br_\bc. When a program which uses the readline li-
+ brary starts up, the initialization file is read, and the key bindings
+ and variables are set. There are only a few basic constructs allowed
+ in the readline initialization file. Blank lines are ignored. Lines
+ beginning with a #\b# are comments. Lines beginning with a $\b$ indicate
+ conditional constructs. Other lines denote key bindings and variable
+ settings.
+
+ The default key-bindings may be changed with an _\bi_\bn_\bp_\bu_\bt_\br_\bc file. Other
programs that use this library may add their own commands and bindings.
For example, placing
M-Control-u: universal-argument
or
C-Meta-u: universal-argument
- into the _\bi_\bn_\bp_\bu_\bt_\br_\bc would make M-C-u execute the readline command _\bu_\bn_\bi_\bv_\be_\br_\b-
+ into the _\bi_\bn_\bp_\bu_\bt_\br_\bc would make M-C-u execute the readline command _\bu_\bn_\bi_\bv_\be_\br_\b-
_\bs_\ba_\bl_\b-_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt.
- The following symbolic character names are recognized: _\bR_\bU_\bB_\bO_\bU_\bT, _\bD_\bE_\bL,
+ The following symbolic character names are recognized: _\bR_\bU_\bB_\bO_\bU_\bT, _\bD_\bE_\bL,
_\bE_\bS_\bC, _\bL_\bF_\bD, _\bN_\bE_\bW_\bL_\bI_\bN_\bE, _\bR_\bE_\bT, _\bR_\bE_\bT_\bU_\bR_\bN, _\bS_\bP_\bC, _\bS_\bP_\bA_\bC_\bE, and _\bT_\bA_\bB.
- In addition to command names, readline allows keys to be bound to a
+ In addition to command names, readline allows keys to be bound to a
string that is inserted when the key is pressed (a _\bm_\ba_\bc_\br_\bo).
R\bRe\bea\bad\bdl\bli\bin\bne\be K\bKe\bey\by B\bBi\bin\bnd\bdi\bin\bng\bgs\bs
- The syntax for controlling key bindings in the _\bi_\bn_\bp_\bu_\bt_\br_\bc file is simple.
- All that is required is the name of the command or the text of a macro
- and a key sequence to which it should be bound. The name may be speci-
+ The syntax for controlling key bindings in the _\bi_\bn_\bp_\bu_\bt_\br_\bc file is simple.
+ All that is required is the name of the command or the text of a macro
+ and a key sequence to which it should be bound. The name may be speci-
fied in one of two ways: as a symbolic key name, possibly with _\bM_\be_\bt_\ba_\b- or
_\bC_\bo_\bn_\bt_\br_\bo_\bl_\b- prefixes, or as a key sequence.
When using the form k\bke\bey\byn\bna\bam\bme\be:_\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be or _\bm_\ba_\bc_\br_\bo, _\bk_\be_\by_\bn_\ba_\bm_\be is the name
- of a key spelled out in English. For example:
+ of a key spelled out in English. For example:
Control-u: universal-argument
Meta-Rubout: backward-kill-word
Control-o: "> output"
- In the above example, _\bC_\b-_\bu is bound to the function u\bun\bni\biv\bve\ber\brs\bsa\bal\bl-\b-a\bar\brg\bgu\bum\bme\ben\bnt\bt,
- _\bM_\b-_\bD_\bE_\bL is bound to the function b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-k\bki\bil\bll\bl-\b-w\bwo\bor\brd\bd, and _\bC_\b-_\bo is bound to
- run the macro expressed on the right hand side (that is, to insert the
+ In the above example, _\bC_\b-_\bu is bound to the function u\bun\bni\biv\bve\ber\brs\bsa\bal\bl-\b-a\bar\brg\bgu\bum\bme\ben\bnt\bt,
+ _\bM_\b-_\bD_\bE_\bL is bound to the function b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-k\bki\bil\bll\bl-\b-w\bwo\bor\brd\bd, and _\bC_\b-_\bo is bound to
+ run the macro expressed on the right hand side (that is, to insert the
text ``> output'' into the line).
- In the second form, "\b"k\bke\bey\bys\bse\beq\bq"\b":_\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be or _\bm_\ba_\bc_\br_\bo, k\bke\bey\bys\bse\beq\bq differs
- from k\bke\bey\byn\bna\bam\bme\be above in that strings denoting an entire key sequence may
- be specified by placing the sequence within double quotes. Some GNU
- Emacs style key escapes can be used, as in the following example, but
+ In the second form, "\b"k\bke\bey\bys\bse\beq\bq"\b":_\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be or _\bm_\ba_\bc_\br_\bo, k\bke\bey\bys\bse\beq\bq differs
+ from k\bke\bey\byn\bna\bam\bme\be above in that strings denoting an entire key sequence may
+ be specified by placing the sequence within double quotes. Some GNU
+ Emacs style key escapes can be used, as in the following example, but
the symbolic character names are not recognized.
"\C-u": universal-argument
"\e[11~": "Function Key 1"
In this example, _\bC_\b-_\bu is again bound to the function u\bun\bni\biv\bve\ber\brs\bsa\bal\bl-\b-a\bar\brg\bgu\bum\bme\ben\bnt\bt.
- _\bC_\b-_\bx _\bC_\b-_\br is bound to the function r\bre\be-\b-r\bre\bea\bad\bd-\b-i\bin\bni\bit\bt-\b-f\bfi\bil\ble\be, and _\bE_\bS_\bC _\b[ _\b1 _\b1 _\b~ is
+ _\bC_\b-_\bx _\bC_\b-_\br is bound to the function r\bre\be-\b-r\bre\bea\bad\bd-\b-i\bin\bni\bit\bt-\b-f\bfi\bil\ble\be, and _\bE_\bS_\bC _\b[ _\b1 _\b1 _\b~ is
bound to insert the text ``Function Key 1''.
The full set of GNU Emacs style escape sequences is
\\b\"\b" literal "
\\b\'\b' literal '
- In addition to the GNU Emacs style escape sequences, a second set of
+ In addition to the GNU Emacs style escape sequences, a second set of
backslash escapes is available:
\\b\a\ba alert (bell)
\\b\b\bb backspace
\\b\r\br carriage return
\\b\t\bt horizontal tab
\\b\v\bv vertical tab
- \\b\_\bn_\bn_\bn the eight-bit character whose value is the octal value
+ \\b\_\bn_\bn_\bn the eight-bit character whose value is the octal value
_\bn_\bn_\bn (one to three digits)
- \\b\x\bx_\bH_\bH the eight-bit character whose value is the hexadecimal
+ \\b\x\bx_\bH_\bH the eight-bit character whose value is the hexadecimal
value _\bH_\bH (one or two hex digits)
When entering the text of a macro, single or double quotes must be used
- to indicate a macro definition. Unquoted text is assumed to be a func-
- tion name. In the macro body, the backslash escapes described above are
- expanded. Backslash will quote any other character in the macro text,
- including " and '.
-
- B\bBa\bas\bsh\bh allows the current readline key bindings to be displayed or modi-
- fied with the b\bbi\bin\bnd\bd builtin command. The editing mode may be switched
- during interactive use by using the -\b-o\bo option to the s\bse\bet\bt builtin com-
+ to indicate a macro definition. Unquoted text is assumed to be a func-
+ tion name. In the macro body, the backslash escapes described above
+ are expanded. Backslash will quote any other character in the macro
+ text, including " and '.
+
+ B\bBa\bas\bsh\bh allows the current readline key bindings to be displayed or modi-
+ fied with the b\bbi\bin\bnd\bd builtin command. The editing mode may be switched
+ during interactive use by using the -\b-o\bo option to the s\bse\bet\bt builtin com-
mand (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
R\bRe\bea\bad\bdl\bli\bin\bne\be V\bVa\bar\bri\bia\bab\bbl\ble\bes\bs
s\bse\bet\bt _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be_\b-_\bn_\ba_\bm_\be _\bv_\ba_\bl_\bu_\be
or using the b\bbi\bin\bnd\bd builtin command (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below).
- Except where noted, readline variables can take the values O\bOn\bn or O\bOf\bff\bf
- (without regard to case). Unrecognized variable names are ignored. When
- a variable value is read, empty or null values, "on" (case-insensi-
- tive), and "1" are equivalent to O\bOn\bn. All other values are equivalent to
- O\bOf\bff\bf. The variables and their default values are:
+ Except where noted, readline variables can take the values O\bOn\bn or O\bOf\bff\bf
+ (without regard to case). Unrecognized variable names are ignored.
+ When a variable value is read, empty or null values, "on" (case-insen-
+ sitive), and "1" are equivalent to O\bOn\bn. All other values are equivalent
+ to O\bOf\bff\bf. The variables and their default values are:
a\bac\bct\bti\biv\bve\be-\b-r\bre\beg\bgi\bio\bon\bn-\b-s\bst\bta\bar\brt\bt-\b-c\bco\bol\blo\bor\br
- A string variable that controls the text color and background
- when displaying the text in the active region (see the descrip-
- tion of e\ben\bna\bab\bbl\ble\be-\b-a\bac\bct\bti\biv\bve\be-\b-r\bre\beg\bgi\bio\bon\bn below). This string must not take
+ A string variable that controls the text color and background
+ when displaying the text in the active region (see the descrip-
+ tion of e\ben\bna\bab\bbl\ble\be-\b-a\bac\bct\bti\biv\bve\be-\b-r\bre\beg\bgi\bio\bon\bn below). This string must not take
up any physical character positions on the display, so it should
- consist only of terminal escape sequences. It is output to the
- terminal before displaying the text in the active region. This
- variable is reset to the default value whenever the terminal
- type changes. The default value is the string that puts the ter-
- minal in standout mode, as obtained from the terminal's terminfo
- description. A sample value might be "\e[01;33m".
+ consist only of terminal escape sequences. It is output to the
+ terminal before displaying the text in the active region. This
+ variable is reset to the default value whenever the terminal
+ type changes. The default value is the string that puts the
+ terminal in standout mode, as obtained from the terminal's ter-
+ minfo description. A sample value might be "\e[01;33m".
a\bac\bct\bti\biv\bve\be-\b-r\bre\beg\bgi\bio\bon\bn-\b-e\ben\bnd\bd-\b-c\bco\bol\blo\bor\br
- A string variable that "undoes" the effects of a\bac\bct\bti\biv\bve\be-\b-r\bre\be-\b-
- g\bgi\bio\bon\bn-\b-s\bst\bta\bar\brt\bt-\b-c\bco\bol\blo\bor\br and restores "normal" terminal display appear-
- ance after displaying text in the active region. This string
- must not take up any physical character positions on the dis-
- play, so it should consist only of terminal escape sequences. It
- is output to the terminal after displaying the text in the ac-
- tive region. This variable is reset to the default value when-
- ever the terminal type changes. The default value is the string
- that restores the terminal from standout mode, as obtained from
- the terminal's terminfo description. A sample value might be
- "\e[0m".
+ A string variable that "undoes" the effects of a\bac\bct\bti\biv\bve\be-\b-r\bre\be-\b-
+ g\bgi\bio\bon\bn-\b-s\bst\bta\bar\brt\bt-\b-c\bco\bol\blo\bor\br and restores "normal" terminal display appear-
+ ance after displaying text in the active region. This string
+ must not take up any physical character positions on the dis-
+ play, so it should consist only of terminal escape sequences.
+ It is output to the terminal after displaying the text in the
+ active region. This variable is reset to the default value
+ whenever the terminal type changes. The default value is the
+ string that restores the terminal from standout mode, as ob-
+ tained from the terminal's terminfo description. A sample value
+ might be "\e[0m".
b\bbe\bel\bll\bl-\b-s\bst\bty\byl\ble\be (\b(a\bau\bud\bdi\bib\bbl\ble\be)\b)
- Controls what happens when readline wants to ring the terminal
- bell. If set to n\bno\bon\bne\be, readline never rings the bell. If set to
- v\bvi\bis\bsi\bib\bbl\ble\be, readline uses a visible bell if one is available. If
+ Controls what happens when readline wants to ring the terminal
+ bell. If set to n\bno\bon\bne\be, readline never rings the bell. If set to
+ v\bvi\bis\bsi\bib\bbl\ble\be, readline uses a visible bell if one is available. If
set to a\bau\bud\bdi\bib\bbl\ble\be, readline attempts to ring the terminal's bell.
b\bbi\bin\bnd\bd-\b-t\btt\bty\by-\b-s\bsp\bpe\bec\bci\bia\bal\bl-\b-c\bch\bha\bar\brs\bs (\b(O\bOn\bn)\b)
- If set to O\bOn\bn (the default), readline attempts to bind the con-
- trol characters that are treated specially by the kernel's ter-
- minal driver to their readline equivalents. These override the
- default readline bindings described here. Type stty -a at a bash
- prompt to see your current terminal settings, including the spe-
- cial control characters (usually c\bcc\bch\bha\bar\brs\bs).
+ If set to O\bOn\bn (the default), readline attempts to bind the con-
+ trol characters that are treated specially by the kernel's ter-
+ minal driver to their readline equivalents. These override the
+ default readline bindings described here. Type stty -a at a
+ bash prompt to see your current terminal settings, including the
+ special control characters (usually c\bcc\bch\bha\bar\brs\bs).
b\bbl\bli\bin\bnk\bk-\b-m\bma\bat\btc\bch\bhi\bin\bng\bg-\b-p\bpa\bar\bre\ben\bn (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, readline attempts to briefly move the cursor to an
opening parenthesis when a closing parenthesis is inserted.
c\bco\bol\blo\bor\bre\bed\bd-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bn-\b-p\bpr\bre\bef\bfi\bix\bx (\b(O\bOf\bff\bf)\b)
- If set to O\bOn\bn, when listing completions, readline displays the
+ If set to O\bOn\bn, when listing completions, readline displays the
common prefix of the set of possible completions using a differ-
- ent color. The color definitions are taken from the value of the
- L\bLS\bS_\b_C\bCO\bOL\bLO\bOR\bRS\bS environment variable. If there is a color definition
- in $\b$L\bLS\bS_\b_C\bCO\bOL\bLO\bOR\bRS\bS for the custom suffix "readline-colored-comple-
- tion-prefix", readline uses this color for the common prefix in-
- stead of its default.
+ ent color. The color definitions are taken from the value of
+ the L\bLS\bS_\b_C\bCO\bOL\bLO\bOR\bRS\bS environment variable. If there is a color defini-
+ tion in $\b$L\bLS\bS_\b_C\bCO\bOL\bLO\bOR\bRS\bS for the custom suffix "readline-colored-com-
+ pletion-prefix", readline uses this color for the common prefix
+ instead of its default.
c\bco\bol\blo\bor\bre\bed\bd-\b-s\bst\bta\bat\bts\bs (\b(O\bOf\bff\bf)\b)
- If set to O\bOn\bn, readline displays possible completions using dif-
- ferent colors to indicate their file type. The color definitions
- are taken from the value of the L\bLS\bS_\b_C\bCO\bOL\bLO\bOR\bRS\bS environment variable.
+ If set to O\bOn\bn, readline displays possible completions using dif-
+ ferent colors to indicate their file type. The color defini-
+ tions are taken from the value of the L\bLS\bS_\b_C\bCO\bOL\bLO\bOR\bRS\bS environment
+ variable.
c\bco\bom\bmm\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn (\b(`\b``\b`#\b#'\b''\b')\b)
The string that is inserted when the readline i\bin\bns\bse\ber\brt\bt-\b-c\bco\bom\bmm\bme\ben\bnt\bt
- command is executed. This command is bound to M\bM-\b-#\b# in emacs mode
+ command is executed. This command is bound to M\bM-\b-#\b# in emacs mode
and to #\b# in vi command mode.
c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bn-\b-d\bdi\bis\bsp\bpl\bla\bay\by-\b-w\bwi\bid\bdt\bth\bh (\b(-\b-1\b1)\b)
The number of screen columns used to display possible matches
- when performing completion. The value is ignored if it is less
- than 0 or greater than the terminal screen width. A value of 0
- will cause matches to be displayed one per line. The default
+ when performing completion. The value is ignored if it is less
+ than 0 or greater than the terminal screen width. A value of 0
+ will cause matches to be displayed one per line. The default
value is -1.
c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bn-\b-i\big\bgn\bno\bor\bre\be-\b-c\bca\bas\bse\be (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, readline performs filename matching and completion
forming case-insensitive filename matching and completion.
c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bn-\b-p\bpr\bre\bef\bfi\bix\bx-\b-d\bdi\bis\bsp\bpl\bla\bay\by-\b-l\ble\ben\bng\bgt\bth\bh (\b(0\b0)\b)
The length in characters of the common prefix of a list of pos-
- sible completions that is displayed without modification. When
+ sible completions that is displayed without modification. When
set to a value greater than zero, common prefixes longer than
this value are replaced with an ellipsis when displaying possi-
ble completions.
This determines when the user is queried about viewing the num-
ber of possible completions generated by the p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-c\bco\bom\bmp\bpl\ble\be-\b-
t\bti\bio\bon\bns\bs command. It may be set to any integer value greater than
- or equal to zero. If the number of possible completions is
+ or equal to zero. If the number of possible completions is
greater than or equal to the value of this variable, readline
will ask whether or not the user wishes to view them; otherwise
- they are simply listed on the terminal. A zero value means read-
- line should never ask; negative values are treated as zero.
+ they are simply listed on the terminal. A zero value means
+ readline should never ask; negative values are treated as zero.
c\bco\bon\bnv\bve\ber\brt\bt-\b-m\bme\bet\bta\ba (\b(O\bOn\bn)\b)
If set to O\bOn\bn, readline will convert characters with the eighth
bit set to an ASCII key sequence by stripping the eighth bit and
prefixing an escape character (in effect, using escape as the
- _\bm_\be_\bt_\ba _\bp_\br_\be_\bf_\bi_\bx). The default is _\bO_\bn, but readline will set it to _\bO_\bf_\bf
- if the locale contains eight-bit characters. This variable is
- dependent on the L\bLC\bC_\b_C\bCT\bTY\bYP\bPE\bE locale category, and may change if the
- locale is changed.
+ _\bm_\be_\bt_\ba _\bp_\br_\be_\bf_\bi_\bx). The default is _\bO_\bn, but readline will set it to
+ _\bO_\bf_\bf if the locale contains eight-bit characters. This variable
+ is dependent on the L\bLC\bC_\b_C\bCT\bTY\bYP\bPE\bE locale category, and may change if
+ the locale is changed.
d\bdi\bis\bsa\bab\bbl\ble\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bn (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, readline will inhibit word completion. Completion
characters will be inserted into the line as if they had been
ated from the keyboard.
e\bed\bdi\bit\bti\bin\bng\bg-\b-m\bmo\bod\bde\be (\b(e\bem\bma\bac\bcs\bs)\b)
Controls whether readline begins with a set of key bindings sim-
- ilar to _\bE_\bm_\ba_\bc_\bs or _\bv_\bi. e\bed\bdi\bit\bti\bin\bng\bg-\b-m\bmo\bod\bde\be can be set to either e\bem\bma\bac\bcs\bs or
+ ilar to _\bE_\bm_\ba_\bc_\bs or _\bv_\bi. e\bed\bdi\bit\bti\bin\bng\bg-\b-m\bmo\bod\bde\be can be set to either e\bem\bma\bac\bcs\bs or
v\bvi\bi.
e\bem\bma\bac\bcs\bs-\b-m\bmo\bod\bde\be-\b-s\bst\btr\bri\bin\bng\bg (\b(@\b@)\b)
If the _\bs_\bh_\bo_\bw_\b-_\bm_\bo_\bd_\be_\b-_\bi_\bn_\b-_\bp_\br_\bo_\bm_\bp_\bt variable is enabled, this string is
displayed immediately before the last line of the primary prompt
- when emacs editing mode is active. The value is expanded like a
+ when emacs editing mode is active. The value is expanded like a
key binding, so the standard set of meta- and control prefixes
- and backslash escape sequences is available. Use the \1 and \2
+ and backslash escape sequences is available. Use the \1 and \2
escapes to begin and end sequences of non-printing characters,
which can be used to embed a terminal control sequence into the
mode string.
e\ben\bna\bab\bbl\ble\be-\b-a\bac\bct\bti\biv\bve\be-\b-r\bre\beg\bgi\bio\bon\bn (\b(O\bOn\bn)\b)
The _\bp_\bo_\bi_\bn_\bt is the current cursor position, and _\bm_\ba_\br_\bk refers to a
- saved cursor position. The text between the point and mark is
+ saved cursor position. The text between the point and mark is
referred to as the _\br_\be_\bg_\bi_\bo_\bn. When this variable is set to _\bO_\bn,
readline allows certain commands to designate the region as _\ba_\bc_\b-
- _\bt_\bi_\bv_\be. When the region is active, readline highlights the text in
- the region using the value of the a\bac\bct\bti\biv\bve\be-\b-r\bre\beg\bgi\bio\bon\bn-\b-s\bst\bta\bar\brt\bt-\b-c\bco\bol\blo\bor\br,
+ _\bt_\bi_\bv_\be. When the region is active, readline highlights the text
+ in the region using the value of the a\bac\bct\bti\biv\bve\be-\b-r\bre\beg\bgi\bio\bon\bn-\b-s\bst\bta\bar\brt\bt-\b-c\bco\bol\blo\bor\br,
which defaults to the string that enables the terminal's stand-
- out mode. The active region shows the text inserted by brack-
+ out mode. The active region shows the text inserted by brack-
eted-paste and any matching text found by incremental and non-
incremental history searches.
e\ben\bna\bab\bbl\ble\be-\b-b\bbr\bra\bac\bck\bke\bet\bte\bed\bd-\b-p\bpa\bas\bst\bte\be (\b(O\bOn\bn)\b)
When set to O\bOn\bn, readline configures the terminal to insert each
paste into the editing buffer as a single string of characters,
instead of treating each character as if it had been read from
- the keyboard. This prevents readline from executing any editing
+ the keyboard. This prevents readline from executing any editing
commands bound to key sequences appearing in the pasted text.
e\ben\bna\bab\bbl\ble\be-\b-k\bke\bey\byp\bpa\bad\bd (\b(O\bOf\bff\bf)\b)
When set to O\bOn\bn, readline will try to enable the application key-
- pad when it is called. Some systems need this to enable the ar-
+ pad when it is called. Some systems need this to enable the ar-
row keys.
e\ben\bna\bab\bbl\ble\be-\b-m\bme\bet\bta\ba-\b-k\bke\bey\by (\b(O\bOn\bn)\b)
When set to O\bOn\bn, readline will try to enable any meta modifier
- key the terminal claims to support when it is called. On many
+ key the terminal claims to support when it is called. On many
terminals, the meta key is used to send eight-bit characters.
e\bex\bxp\bpa\ban\bnd\bd-\b-t\bti\bil\bld\bde\be (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, tilde expansion is performed when readline at-
t\bto\bor\bry\by or n\bne\bex\bxt\bt-\b-h\bhi\bis\bst\bto\bor\bry\by.
h\bhi\bis\bst\bto\bor\bry\by-\b-s\bsi\biz\bze\be (\b(u\bun\bns\bse\bet\bt)\b)
Set the maximum number of history entries saved in the history
- list. If set to zero, any existing history entries are deleted
- and no new entries are saved. If set to a value less than zero,
+ list. If set to zero, any existing history entries are deleted
+ and no new entries are saved. If set to a value less than zero,
the number of history entries is not limited. By default, the
number of history entries is set to the value of the H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE
- shell variable. If an attempt is made to set _\bh_\bi_\bs_\bt_\bo_\br_\by_\b-_\bs_\bi_\bz_\be to a
+ shell variable. If an attempt is made to set _\bh_\bi_\bs_\bt_\bo_\br_\by_\b-_\bs_\bi_\bz_\be to a
non-numeric value, the maximum number of history entries will be
set to 500.
h\bho\bor\bri\biz\bzo\bon\bnt\bta\bal\bl-\b-s\bsc\bcr\bro\bol\bll\bl-\b-m\bmo\bod\bde\be (\b(O\bOf\bff\bf)\b)
When set to O\bOn\bn, makes readline use a single line for display,
scrolling the input horizontally on a single screen line when it
becomes longer than the screen width rather than wrapping to a
- new line. This setting is automatically enabled for terminals of
- height 1.
+ new line. This setting is automatically enabled for terminals
+ of height 1.
i\bin\bnp\bpu\but\bt-\b-m\bme\bet\bta\ba (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, readline will enable eight-bit input (that is, it
will not strip the eighth bit from the characters it reads), re-
- gardless of what the terminal claims it can support. The name
- m\bme\bet\bta\ba-\b-f\bfl\bla\bag\bg is a synonym for this variable. The default is _\bO_\bf_\bf,
+ gardless of what the terminal claims it can support. The name
+ m\bme\bet\bta\ba-\b-f\bfl\bla\bag\bg is a synonym for this variable. The default is _\bO_\bf_\bf,
but readline will set it to _\bO_\bn if the locale contains eight-bit
- characters. This variable is dependent on the L\bLC\bC_\b_C\bCT\bTY\bYP\bPE\bE locale
+ characters. This variable is dependent on the L\bLC\bC_\b_C\bCT\bTY\bYP\bPE\bE locale
category, and may change if the locale is changed.
i\bis\bse\bea\bar\brc\bch\bh-\b-t\bte\ber\brm\bmi\bin\bna\bat\bto\bor\brs\bs (\b(`\b``\b`C\bC-\b-[\b[C\bC-\b-J\bJ'\b''\b')\b)
The string of characters that should terminate an incremental
search without subsequently executing the character as a com-
- mand. If this variable has not been given a value, the charac-
+ mand. If this variable has not been given a value, the charac-
ters _\bE_\bS_\bC and _\bC_\b-_\bJ will terminate an incremental search.
k\bke\bey\bym\bma\bap\bp (\b(e\bem\bma\bac\bcs\bs)\b)
- Set the current readline keymap. The set of valid keymap names
+ Set the current readline keymap. The set of valid keymap names
is _\be_\bm_\ba_\bc_\bs_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bm_\be_\bt_\ba_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bc_\bt_\bl_\bx_\b, _\bv_\bi_\b, _\bv_\bi_\b-_\bc_\bo_\bm_\b-
_\bm_\ba_\bn_\bd, and _\bv_\bi_\b-_\bi_\bn_\bs_\be_\br_\bt. _\bv_\bi is equivalent to _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd; _\be_\bm_\ba_\bc_\bs is
- equivalent to _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd. The default value is _\be_\bm_\ba_\bc_\bs; the
+ equivalent to _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd. The default value is _\be_\bm_\ba_\bc_\bs; the
value of e\bed\bdi\bit\bti\bin\bng\bg-\b-m\bmo\bod\bde\be also affects the default keymap.
k\bke\bey\bys\bse\beq\bq-\b-t\bti\bim\bme\beo\bou\but\bt (\b(5\b50\b00\b0)\b)
Specifies the duration _\br_\be_\ba_\bd_\bl_\bi_\bn_\be will wait for a character when
reading an ambiguous key sequence (one that can form a complete
key sequence using the input read so far, or can take additional
- input to complete a longer key sequence). If no input is re-
+ input to complete a longer key sequence). If no input is re-
ceived within the timeout, _\br_\be_\ba_\bd_\bl_\bi_\bn_\be will use the shorter but
- complete key sequence. The value is specified in milliseconds,
+ complete key sequence. The value is specified in milliseconds,
so a value of 1000 means that _\br_\be_\ba_\bd_\bl_\bi_\bn_\be will wait one second for
- additional input. If this variable is set to a value less than
+ additional input. If this variable is set to a value less than
or equal to zero, or to a non-numeric value, _\br_\be_\ba_\bd_\bl_\bi_\bn_\be will wait
until another key is pressed to decide which key sequence to
complete.
m\bma\bat\btc\bch\bh-\b-h\bhi\bid\bdd\bde\ben\bn-\b-f\bfi\bil\ble\bes\bs (\b(O\bOn\bn)\b)
This variable, when set to O\bOn\bn, causes readline to match files
whose names begin with a `.' (hidden files) when performing
- filename completion. If set to O\bOf\bff\bf, the leading `.' must be sup-
- plied by the user in the filename to be completed.
+ filename completion. If set to O\bOf\bff\bf, the leading `.' must be
+ supplied by the user in the filename to be completed.
m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-d\bdi\bis\bsp\bpl\bla\bay\by-\b-p\bpr\bre\bef\bfi\bix\bx (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, menu completion displays the common prefix of the
list of possible completions (which may be empty) before cycling
If set to O\bOn\bn, readline will display characters with the eighth
bit set directly rather than as a meta-prefixed escape sequence.
The default is _\bO_\bf_\bf, but readline will set it to _\bO_\bn if the locale
- contains eight-bit characters. This variable is dependent on the
- L\bLC\bC_\b_C\bCT\bTY\bYP\bPE\bE locale category, and may change if the locale is
+ contains eight-bit characters. This variable is dependent on
+ the L\bLC\bC_\b_C\bCT\bTY\bYP\bPE\bE locale category, and may change if the locale is
changed.
p\bpa\bag\bge\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs (\b(O\bOn\bn)\b)
If set to O\bOn\bn, readline uses an internal _\bm_\bo_\br_\be-like pager to dis-
screen.
r\bre\bev\bve\ber\brt\bt-\b-a\bal\bll\bl-\b-a\bat\bt-\b-n\bne\bew\bwl\bli\bin\bne\be (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, readline will undo all changes to history lines
- before returning when a\bac\bcc\bce\bep\bpt\bt-\b-l\bli\bin\bne\be is executed. By default, his-
+ before returning when a\bac\bcc\bce\bep\bpt\bt-\b-l\bli\bin\bne\be is executed. By default, his-
tory lines may be modified and retain individual undo lists
across calls to r\bre\bea\bad\bdl\bli\bin\bne\be.
s\bse\bea\bar\brc\bch\bh-\b-i\big\bgn\bno\bor\bre\be-\b-c\bca\bas\bse\be (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, readline performs incremental and non-incremental
history list searches in a case-insensitive fashion.
s\bsh\bho\bow\bw-\b-a\bal\bll\bl-\b-i\bif\bf-\b-a\bam\bmb\bbi\big\bgu\buo\bou\bus\bs (\b(O\bOf\bff\bf)\b)
- This alters the default behavior of the completion functions. If
- set to O\bOn\bn, words which have more than one possible completion
+ This alters the default behavior of the completion functions.
+ If set to O\bOn\bn, words which have more than one possible completion
cause the matches to be listed immediately instead of ringing
the bell.
s\bsh\bho\bow\bw-\b-a\bal\bll\bl-\b-i\bif\bf-\b-u\bun\bnm\bmo\bod\bdi\bif\bfi\bie\bed\bd (\b(O\bOf\bff\bf)\b)
This alters the default behavior of the completion functions in
- a fashion similar to s\bsh\bho\bow\bw-\b-a\bal\bll\bl-\b-i\bif\bf-\b-a\bam\bmb\bbi\big\bgu\buo\bou\bus\bs. If set to O\bOn\bn, words
+ a fashion similar to s\bsh\bho\bow\bw-\b-a\bal\bll\bl-\b-i\bif\bf-\b-a\bam\bmb\bbi\big\bgu\buo\bou\bus\bs. If set to O\bOn\bn, words
which have more than one possible completion without any possi-
ble partial completion (the possible completions don't share a
common prefix) cause the matches to be listed immediately in-
stead of ringing the bell.
s\bsh\bho\bow\bw-\b-m\bmo\bod\bde\be-\b-i\bin\bn-\b-p\bpr\bro\bom\bmp\bpt\bt (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, add a string to the beginning of the prompt indi-
- cating the editing mode: emacs, vi command, or vi insertion. The
- mode strings are user-settable (e.g., _\be_\bm_\ba_\bc_\bs_\b-_\bm_\bo_\bd_\be_\b-_\bs_\bt_\br_\bi_\bn_\bg).
+ cating the editing mode: emacs, vi command, or vi insertion.
+ The mode strings are user-settable (e.g., _\be_\bm_\ba_\bc_\bs_\b-_\bm_\bo_\bd_\be_\b-_\bs_\bt_\br_\bi_\bn_\bg).
s\bsk\bki\bip\bp-\b-c\bco\bom\bmp\bpl\ble\bet\bte\bed\bd-\b-t\bte\bex\bxt\bt (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, this alters the default completion behavior when
- inserting a single match into the line. It's only active when
- performing completion in the middle of a word. If enabled, read-
- line does not insert characters from the completion that match
- characters after point in the word being completed, so portions
- of the word following the cursor are not duplicated.
+ inserting a single match into the line. It's only active when
+ performing completion in the middle of a word. If enabled,
+ readline does not insert characters from the completion that
+ match characters after point in the word being completed, so
+ portions of the word following the cursor are not duplicated.
v\bvi\bi-\b-c\bcm\bmd\bd-\b-m\bmo\bod\bde\be-\b-s\bst\btr\bri\bin\bng\bg (\b((\b(c\bcm\bmd\bd)\b))\b)
If the _\bs_\bh_\bo_\bw_\b-_\bm_\bo_\bd_\be_\b-_\bi_\bn_\b-_\bp_\br_\bo_\bm_\bp_\bt variable is enabled, this string is
displayed immediately before the last line of the primary prompt
- when vi editing mode is active and in command mode. The value is
- expanded like a key binding, so the standard set of meta- and
+ when vi editing mode is active and in command mode. The value
+ is expanded like a key binding, so the standard set of meta- and
control prefixes and backslash escape sequences is available.
Use the \1 and \2 escapes to begin and end sequences of non-
printing characters, which can be used to embed a terminal con-
v\bvi\bi-\b-i\bin\bns\bs-\b-m\bmo\bod\bde\be-\b-s\bst\btr\bri\bin\bng\bg (\b((\b(i\bin\bns\bs)\b))\b)
If the _\bs_\bh_\bo_\bw_\b-_\bm_\bo_\bd_\be_\b-_\bi_\bn_\b-_\bp_\br_\bo_\bm_\bp_\bt variable is enabled, this string is
displayed immediately before the last line of the primary prompt
- when vi editing mode is active and in insertion mode. The value
+ when vi editing mode is active and in insertion mode. The value
is expanded like a key binding, so the standard set of meta- and
control prefixes and backslash escape sequences is available.
Use the \1 and \2 escapes to begin and end sequences of non-
R\bRe\bea\bad\bdl\bli\bin\bne\be C\bCo\bon\bnd\bdi\bit\bti\bio\bon\bna\bal\bl C\bCo\bon\bns\bst\btr\bru\buc\bct\bts\bs
Readline implements a facility similar in spirit to the conditional
compilation features of the C preprocessor which allows key bindings
- and variable settings to be performed as the result of tests. There are
- four parser directives used.
+ and variable settings to be performed as the result of tests. There
+ are four parser directives used.
$\b$i\bif\bf The $\b$i\bif\bf construct allows bindings to be made based on the edit-
ing mode, the terminal being used, or the application using
- readline. The text of the test, after any comparison operator,
+ readline. The text of the test, after any comparison operator,
extends to the end of the line; unless otherwise noted, no char-
acters are required to isolate it.
m\bmo\bod\bde\be The m\bmo\bod\bde\be=\b= form of the $\b$i\bif\bf directive is used to test
- whether readline is in emacs or vi mode. This may be used
- in conjunction with the s\bse\bet\bt k\bke\bey\bym\bma\bap\bp command, for instance,
- to set bindings in the _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd and _\be_\bm_\ba_\bc_\bs_\b-_\bc_\bt_\bl_\bx
- keymaps only if readline is starting out in emacs mode.
+ whether readline is in emacs or vi mode. This may be
+ used in conjunction with the s\bse\bet\bt k\bke\bey\bym\bma\bap\bp command, for in-
+ stance, to set bindings in the _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd and
+ _\be_\bm_\ba_\bc_\bs_\b-_\bc_\bt_\bl_\bx keymaps only if readline is starting out in
+ emacs mode.
- t\bte\ber\brm\bm The t\bte\ber\brm\bm=\b= form may be used to include terminal-specific
+ t\bte\ber\brm\bm The t\bte\ber\brm\bm=\b= form may be used to include terminal-specific
key bindings, perhaps to bind the key sequences output by
- the terminal's function keys. The word on the right side
+ the terminal's function keys. The word on the right side
of the =\b= is tested against both the full name of the ter-
- minal and the portion of the terminal name before the
- first -\b-. This allows _\bs_\bu_\bn to match both _\bs_\bu_\bn and _\bs_\bu_\bn_\b-_\bc_\bm_\bd,
+ minal and the portion of the terminal name before the
+ first -\b-. This allows _\bs_\bu_\bn to match both _\bs_\bu_\bn and _\bs_\bu_\bn_\b-_\bc_\bm_\bd,
for instance.
v\bve\ber\brs\bsi\bio\bon\bn
- The v\bve\ber\brs\bsi\bio\bon\bn test may be used to perform comparisons
- against specific readline versions. The v\bve\ber\brs\bsi\bio\bon\bn expands
- to the current readline version. The set of comparison
- operators includes =\b=, (and =\b==\b=), !\b!=\b=, <\b<=\b=, >\b>=\b=, <\b<, and >\b>. The
- version number supplied on the right side of the operator
- consists of a major version number, an optional decimal
- point, and an optional minor version (e.g., 7\b7.\b.1\b1). If the
- minor version is omitted, it is assumed to be 0\b0. The op-
- erator may be separated from the string v\bve\ber\brs\bsi\bio\bon\bn and from
- the version number argument by whitespace.
+ The v\bve\ber\brs\bsi\bio\bon\bn test may be used to perform comparisons
+ against specific readline versions. The v\bve\ber\brs\bsi\bio\bon\bn expands
+ to the current readline version. The set of comparison
+ operators includes =\b=, (and =\b==\b=), !\b!=\b=, <\b<=\b=, >\b>=\b=, <\b<, and >\b>.
+ The version number supplied on the right side of the op-
+ erator consists of a major version number, an optional
+ decimal point, and an optional minor version (e.g., 7\b7.\b.1\b1).
+ If the minor version is omitted, it is assumed to be 0\b0.
+ The operator may be separated from the string v\bve\ber\brs\bsi\bio\bon\bn and
+ from the version number argument by whitespace.
a\bap\bpp\bpl\bli\bic\bca\bat\bti\bio\bon\bn
The a\bap\bpp\bpl\bli\bic\bca\bat\bti\bio\bon\bn construct is used to include application-
- specific settings. Each program using the readline li-
- brary sets the _\ba_\bp_\bp_\bl_\bi_\bc_\ba_\bt_\bi_\bo_\bn _\bn_\ba_\bm_\be, and an initialization
- file can test for a particular value. This could be used
- to bind key sequences to functions useful for a specific
- program. For instance, the following command adds a key
- sequence that quotes the current or previous word in
+ specific settings. Each program using the readline li-
+ brary sets the _\ba_\bp_\bp_\bl_\bi_\bc_\ba_\bt_\bi_\bo_\bn _\bn_\ba_\bm_\be, and an initialization
+ file can test for a particular value. This could be used
+ to bind key sequences to functions useful for a specific
+ program. For instance, the following command adds a key
+ sequence that quotes the current or previous word in
b\bba\bas\bsh\bh:
$\b$i\bif\bf Bash
_\bv_\ba_\br_\bi_\ba_\bb_\bl_\be
The _\bv_\ba_\br_\bi_\ba_\bb_\bl_\be construct provides simple equality tests for
- readline variables and values. The permitted comparison
- operators are _\b=, _\b=_\b=, and _\b!_\b=. The variable name must be
+ readline variables and values. The permitted comparison
+ operators are _\b=, _\b=_\b=, and _\b!_\b=. The variable name must be
separated from the comparison operator by whitespace; the
- operator may be separated from the value on the right
- hand side by whitespace. Both string and boolean vari-
- ables may be tested. Boolean variables must be tested
+ operator may be separated from the value on the right
+ hand side by whitespace. Both string and boolean vari-
+ ables may be tested. Boolean variables must be tested
against the values _\bo_\bn and _\bo_\bf_\bf.
$\b$e\ben\bnd\bdi\bif\bf This command, as seen in the previous example, terminates an $\b$i\bif\bf
test fails.
$\b$i\bin\bnc\bcl\blu\bud\bde\be
- This directive takes a single filename as an argument and reads
- commands and bindings from that file. For example, the following
- directive would read _\b/_\be_\bt_\bc_\b/_\bi_\bn_\bp_\bu_\bt_\br_\bc:
+ This directive takes a single filename as an argument and reads
+ commands and bindings from that file. For example, the follow-
+ ing directive would read _\b/_\be_\bt_\bc_\b/_\bi_\bn_\bp_\bu_\bt_\br_\bc:
$\b$i\bin\bnc\bcl\blu\bud\bde\be _\b/_\be_\bt_\bc_\b/_\bi_\bn_\bp_\bu_\bt_\br_\bc
S\bSe\bea\bar\brc\bch\bhi\bin\bng\bg
- Readline provides commands for searching through the command history
- (see H\bHI\bIS\bST\bTO\bOR\bRY\bY below) for lines containing a specified string. There are
+ Readline provides commands for searching through the command history
+ (see H\bHI\bIS\bST\bTO\bOR\bRY\bY below) for lines containing a specified string. There are
two search modes: _\bi_\bn_\bc_\br_\be_\bm_\be_\bn_\bt_\ba_\bl and _\bn_\bo_\bn_\b-_\bi_\bn_\bc_\br_\be_\bm_\be_\bn_\bt_\ba_\bl.
- Incremental searches begin before the user has finished typing the
- search string. As each character of the search string is typed, read-
+ Incremental searches begin before the user has finished typing the
+ search string. As each character of the search string is typed, read-
line displays the next entry from the history matching the string typed
- so far. An incremental search requires only as many characters as
- needed to find the desired history entry. The characters present in the
- value of the i\bis\bse\bea\bar\brc\bch\bh-\b-t\bte\ber\brm\bmi\bin\bna\bat\bto\bor\brs\bs variable are used to terminate an in-
- cremental search. If that variable has not been assigned a value the
- Escape and Control-J characters will terminate an incremental search.
- Control-G will abort an incremental search and restore the original
- line. When the search is terminated, the history entry containing the
+ so far. An incremental search requires only as many characters as
+ needed to find the desired history entry. The characters present in
+ the value of the i\bis\bse\bea\bar\brc\bch\bh-\b-t\bte\ber\brm\bmi\bin\bna\bat\bto\bor\brs\bs variable are used to terminate an
+ incremental search. If that variable has not been assigned a value the
+ Escape and Control-J characters will terminate an incremental search.
+ Control-G will abort an incremental search and restore the original
+ line. When the search is terminated, the history entry containing the
search string becomes the current line.
- To find other matching entries in the history list, type Control-S or
- Control-R as appropriate. This will search backward or forward in the
- history for the next entry matching the search string typed so far. Any
- other key sequence bound to a readline command will terminate the
- search and execute that command. For instance, a _\bn_\be_\bw_\bl_\bi_\bn_\be will terminate
- the search and accept the line, thereby executing the command from the
- history list.
+ To find other matching entries in the history list, type Control-S or
+ Control-R as appropriate. This will search backward or forward in the
+ history for the next entry matching the search string typed so far.
+ Any other key sequence bound to a readline command will terminate the
+ search and execute that command. For instance, a _\bn_\be_\bw_\bl_\bi_\bn_\be will termi-
+ nate the search and accept the line, thereby executing the command from
+ the history list.
- Readline remembers the last incremental search string. If two Control-
- Rs are typed without any intervening characters defining a new search
+ Readline remembers the last incremental search string. If two Control-
+ Rs are typed without any intervening characters defining a new search
string, any remembered search string is used.
- Non-incremental searches read the entire search string before starting
- to search for matching history lines. The search string may be typed by
- the user or be part of the contents of the current line.
+ Non-incremental searches read the entire search string before starting
+ to search for matching history lines. The search string may be typed
+ by the user or be part of the contents of the current line.
R\bRe\bea\bad\bdl\bli\bin\bne\be C\bCo\bom\bmm\bma\ban\bnd\bd N\bNa\bam\bme\bes\bs
- The following is a list of the names of the commands and the default
- key sequences to which they are bound. Command names without an accom-
- panying key sequence are unbound by default. In the following descrip-
- tions, _\bp_\bo_\bi_\bn_\bt refers to the current cursor position, and _\bm_\ba_\br_\bk refers to
- a cursor position saved by the s\bse\bet\bt-\b-m\bma\bar\brk\bk command. The text between the
+ The following is a list of the names of the commands and the default
+ key sequences to which they are bound. Command names without an accom-
+ panying key sequence are unbound by default. In the following descrip-
+ tions, _\bp_\bo_\bi_\bn_\bt refers to the current cursor position, and _\bm_\ba_\br_\bk refers to
+ a cursor position saved by the s\bse\bet\bt-\b-m\bma\bar\brk\bk command. The text between the
point and mark is referred to as the _\br_\be_\bg_\bi_\bo_\bn.
C\bCo\bom\bmm\bma\ban\bnd\bds\bs f\bfo\bor\br M\bMo\bov\bvi\bin\bng\bg
b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-c\bch\bha\bar\br (\b(C\bC-\b-b\bb)\b)
Move back a character.
f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-f\bf)\b)
- Move forward to the end of the next word. Words are composed of
+ Move forward to the end of the next word. Words are composed of
alphanumeric characters (letters and digits).
b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-b\bb)\b)
- Move back to the start of the current or previous word. Words
+ Move back to the start of the current or previous word. Words
are composed of alphanumeric characters (letters and digits).
s\bsh\bhe\bel\bll\bl-\b-f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd
- Move forward to the end of the next word. Words are delimited by
- non-quoted shell metacharacters.
+ Move forward to the end of the next word. Words are delimited
+ by non-quoted shell metacharacters.
s\bsh\bhe\bel\bll\bl-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd
- Move back to the start of the current or previous word. Words
+ Move back to the start of the current or previous word. Words
are delimited by non-quoted shell metacharacters.
p\bpr\bre\bev\bvi\bio\bou\bus\bs-\b-s\bsc\bcr\bre\bee\ben\bn-\b-l\bli\bin\bne\be
- Attempt to move point to the same physical screen column on the
- previous physical screen line. This will not have the desired
- effect if the current readline line does not take up more than
- one physical line or if point is not greater than the length of
+ Attempt to move point to the same physical screen column on the
+ previous physical screen line. This will not have the desired
+ effect if the current readline line does not take up more than
+ one physical line or if point is not greater than the length of
the prompt plus the screen width.
n\bne\bex\bxt\bt-\b-s\bsc\bcr\bre\bee\ben\bn-\b-l\bli\bin\bne\be
- Attempt to move point to the same physical screen column on the
+ Attempt to move point to the same physical screen column on the
next physical screen line. This will not have the desired effect
- if the current readline line does not take up more than one
- physical line or if the length of the current readline line is
+ if the current readline line does not take up more than one
+ physical line or if the length of the current readline line is
not greater than the length of the prompt plus the screen width.
c\bcl\ble\bea\bar\br-\b-d\bdi\bis\bsp\bpl\bla\bay\by (\b(M\bM-\b-C\bC-\b-l\bl)\b)
- Clear the screen and, if possible, the terminal's scrollback
- buffer, then redraw the current line, leaving the current line
+ Clear the screen and, if possible, the terminal's scrollback
+ buffer, then redraw the current line, leaving the current line
at the top of the screen.
c\bcl\ble\bea\bar\br-\b-s\bsc\bcr\bre\bee\ben\bn (\b(C\bC-\b-l\bl)\b)
Clear the screen, then redraw the current line, leaving the cur-
- rent line at the top of the screen. With an argument, refresh
+ rent line at the top of the screen. With an argument, refresh
the current line without clearing the screen.
r\bre\bed\bdr\bra\baw\bw-\b-c\bcu\bur\brr\bre\ben\bnt\bt-\b-l\bli\bin\bne\be
Refresh the current line.
C\bCo\bom\bmm\bma\ban\bnd\bds\bs f\bfo\bor\br M\bMa\ban\bni\bip\bpu\bul\bla\bat\bti\bin\bng\bg t\bth\bhe\be H\bHi\bis\bst\bto\bor\bry\by
a\bac\bcc\bce\bep\bpt\bt-\b-l\bli\bin\bne\be (\b(N\bNe\bew\bwl\bli\bin\bne\be,\b, R\bRe\bet\btu\bur\brn\bn)\b)
- Accept the line regardless of where the cursor is. If this line
- is non-empty, add it to the history list according to the state
- of the H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL variable. If the line is a modified history
+ Accept the line regardless of where the cursor is. If this line
+ is non-empty, add it to the history list according to the state
+ of the H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL variable. If the line is a modified history
line, then restore the history line to its original state.
p\bpr\bre\bev\bvi\bio\bou\bus\bs-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(C\bC-\b-p\bp)\b)
Fetch the previous command from the history list, moving back in
the list.
n\bne\bex\bxt\bt-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(C\bC-\b-n\bn)\b)
- Fetch the next command from the history list, moving forward in
+ Fetch the next command from the history list, moving forward in
the list.
b\bbe\beg\bgi\bin\bnn\bni\bin\bng\bg-\b-o\bof\bf-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(M\bM-\b-<\b<)\b)
Move to the first line in the history.
e\ben\bnd\bd-\b-o\bof\bf-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(M\bM-\b->\b>)\b)
- Move to the end of the input history, i.e., the line currently
+ Move to the end of the input history, i.e., the line currently
being entered.
o\bop\bpe\ber\bra\bat\bte\be-\b-a\ban\bnd\bd-\b-g\bge\bet\bt-\b-n\bne\bex\bxt\bt (\b(C\bC-\b-o\bo)\b)
- Accept the current line for execution and fetch the next line
- relative to the current line from the history for editing. A nu-
- meric argument, if supplied, specifies the history entry to use
- instead of the current line.
+ Accept the current line for execution and fetch the next line
+ relative to the current line from the history for editing. A
+ numeric argument, if supplied, specifies the history entry to
+ use instead of the current line.
f\bfe\bet\btc\bch\bh-\b-h\bhi\bis\bst\bto\bor\bry\by
- With a numeric argument, fetch that entry from the history list
- and make it the current line. Without an argument, move back to
+ With a numeric argument, fetch that entry from the history list
+ and make it the current line. Without an argument, move back to
the first entry in the history list.
r\bre\bev\bve\ber\brs\bse\be-\b-s\bse\bea\bar\brc\bch\bh-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(C\bC-\b-r\br)\b)
- Search backward starting at the current line and moving `up'
- through the history as necessary. This is an incremental search.
+ Search backward starting at the current line and moving `up'
+ through the history as necessary. This is an incremental
+ search.
f\bfo\bor\brw\bwa\bar\brd\bd-\b-s\bse\bea\bar\brc\bch\bh-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(C\bC-\b-s\bs)\b)
Search forward starting at the current line and moving `down'
- through the history as necessary. This is an incremental search.
+ through the history as necessary. This is an incremental
+ search.
n\bno\bon\bn-\b-i\bin\bnc\bcr\bre\bem\bme\ben\bnt\bta\bal\bl-\b-r\bre\bev\bve\ber\brs\bse\be-\b-s\bse\bea\bar\brc\bch\bh-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(M\bM-\b-p\bp)\b)
Search backward through the history starting at the current line
- using a non-incremental search for a string supplied by the
+ using a non-incremental search for a string supplied by the
user.
n\bno\bon\bn-\b-i\bin\bnc\bcr\bre\bem\bme\ben\bnt\bta\bal\bl-\b-f\bfo\bor\brw\bwa\bar\brd\bd-\b-s\bse\bea\bar\brc\bch\bh-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(M\bM-\b-n\bn)\b)
- Search forward through the history using a non-incremental
+ Search forward through the history using a non-incremental
search for a string supplied by the user.
h\bhi\bis\bst\bto\bor\bry\by-\b-s\bse\bea\bar\brc\bch\bh-\b-f\bfo\bor\brw\bwa\bar\brd\bd
- Search forward through the history for the string of characters
- between the start of the current line and the point. This is a
+ Search forward through the history for the string of characters
+ between the start of the current line and the point. This is a
non-incremental search.
h\bhi\bis\bst\bto\bor\bry\by-\b-s\bse\bea\bar\brc\bch\bh-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd
Search backward through the history for the string of characters
- between the start of the current line and the point. This is a
+ between the start of the current line and the point. This is a
non-incremental search.
h\bhi\bis\bst\bto\bor\bry\by-\b-s\bsu\bub\bbs\bst\btr\bri\bin\bng\bg-\b-s\bse\bea\bar\brc\bch\bh-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd
Search backward through the history for the string of characters
between the start of the current line and the current cursor po-
- sition (the _\bp_\bo_\bi_\bn_\bt). The search string may match anywhere in a
- history line. This is a non-incremental search.
+ sition (the _\bp_\bo_\bi_\bn_\bt). The search string may match anywhere in a
+ history line. This is a non-incremental search.
h\bhi\bis\bst\bto\bor\bry\by-\b-s\bsu\bub\bbs\bst\btr\bri\bin\bng\bg-\b-s\bse\bea\bar\brc\bch\bh-\b-f\bfo\bor\brw\bwa\bar\brd\bd
- Search forward through the history for the string of characters
- between the start of the current line and the point. The search
- string may match anywhere in a history line. This is a non-in-
+ Search forward through the history for the string of characters
+ between the start of the current line and the point. The search
+ string may match anywhere in a history line. This is a non-in-
cremental search.
y\bya\ban\bnk\bk-\b-n\bnt\bth\bh-\b-a\bar\brg\bg (\b(M\bM-\b-C\bC-\b-y\by)\b)
- Insert the first argument to the previous command (usually the
- second word on the previous line) at point. With an argument _\bn,
- insert the _\bnth word from the previous command (the words in the
- previous command begin with word 0). A negative argument inserts
- the _\bnth word from the end of the previous command. Once the ar-
- gument _\bn is computed, the argument is extracted as if the "!_\bn"
- history expansion had been specified.
+ Insert the first argument to the previous command (usually the
+ second word on the previous line) at point. With an argument _\bn,
+ insert the _\bnth word from the previous command (the words in the
+ previous command begin with word 0). A negative argument in-
+ serts the _\bnth word from the end of the previous command. Once
+ the argument _\bn is computed, the argument is extracted as if the
+ "!_\bn" history expansion had been specified.
y\bya\ban\bnk\bk-\b-l\bla\bas\bst\bt-\b-a\bar\brg\bg (\b(M\bM-\b-.\b.,\b, M\bM-\b-_\b_)\b)
- Insert the last argument to the previous command (the last word
- of the previous history entry). With a numeric argument, behave
- exactly like y\bya\ban\bnk\bk-\b-n\bnt\bth\bh-\b-a\bar\brg\bg. Successive calls to y\bya\ban\bnk\bk-\b-l\bla\bas\bst\bt-\b-a\bar\brg\bg
- move back through the history list, inserting the last word (or
- the word specified by the argument to the first call) of each
- line in turn. Any numeric argument supplied to these successive
- calls determines the direction to move through the history. A
- negative argument switches the direction through the history
- (back or forward). The history expansion facilities are used to
+ Insert the last argument to the previous command (the last word
+ of the previous history entry). With a numeric argument, behave
+ exactly like y\bya\ban\bnk\bk-\b-n\bnt\bth\bh-\b-a\bar\brg\bg. Successive calls to y\bya\ban\bnk\bk-\b-l\bla\bas\bst\bt-\b-a\bar\brg\bg
+ move back through the history list, inserting the last word (or
+ the word specified by the argument to the first call) of each
+ line in turn. Any numeric argument supplied to these successive
+ calls determines the direction to move through the history. A
+ negative argument switches the direction through the history
+ (back or forward). The history expansion facilities are used to
extract the last word, as if the "!$" history expansion had been
specified.
s\bsh\bhe\bel\bll\bl-\b-e\bex\bxp\bpa\ban\bnd\bd-\b-l\bli\bin\bne\be (\b(M\bM-\b-C\bC-\b-e\be)\b)
- Expand the line by performing shell word expansions. This per-
+ Expand the line by performing shell word expansions. This per-
forms alias and history expansion, $\b$'_\bs_\bt_\br_\bi_\bn_\bg' and $\b$"_\bs_\bt_\br_\bi_\bn_\bg" quot-
- ing, tilde expansion, parameter and variable expansion, arith-
- metic expansion, word splitting, and quote removal. See H\bHI\bIS\bST\bTO\bOR\bRY\bY
+ ing, tilde expansion, parameter and variable expansion, arith-
+ metic expansion, word splitting, and quote removal. See H\bHI\bIS\bST\bTO\bOR\bRY\bY
E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN below for a description of history expansion.
h\bhi\bis\bst\bto\bor\bry\by-\b-e\bex\bxp\bpa\ban\bnd\bd-\b-l\bli\bin\bne\be (\b(M\bM-\b-^\b^)\b)
- Perform history expansion on the current line. See H\bHI\bIS\bST\bTO\bOR\bRY\bY E\bEX\bX-\b-
+ Perform history expansion on the current line. See H\bHI\bIS\bST\bTO\bOR\bRY\bY E\bEX\bX-\b-
P\bPA\bAN\bNS\bSI\bIO\bON\bN below for a description of history expansion.
m\bma\bag\bgi\bic\bc-\b-s\bsp\bpa\bac\bce\be
- Perform history expansion on the current line and insert a
+ Perform history expansion on the current line and insert a
space. See H\bHI\bIS\bST\bTO\bOR\bRY\bY E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN below for a description of history
expansion.
a\bal\bli\bia\bas\bs-\b-e\bex\bxp\bpa\ban\bnd\bd-\b-l\bli\bin\bne\be
- Perform alias expansion on the current line. See A\bAL\bLI\bIA\bAS\bSE\bES\bS above
+ Perform alias expansion on the current line. See A\bAL\bLI\bIA\bAS\bSE\bES\bS above
for a description of alias expansion.
h\bhi\bis\bst\bto\bor\bry\by-\b-a\ban\bnd\bd-\b-a\bal\bli\bia\bas\bs-\b-e\bex\bxp\bpa\ban\bnd\bd-\b-l\bli\bin\bne\be
Perform history and alias expansion on the current line.
i\bin\bns\bse\ber\brt\bt-\b-l\bla\bas\bst\bt-\b-a\bar\brg\bgu\bum\bme\ben\bnt\bt (\b(M\bM-\b-.\b.,\b, M\bM-\b-_\b_)\b)
A synonym for y\bya\ban\bnk\bk-\b-l\bla\bas\bst\bt-\b-a\bar\brg\bg.
e\bed\bdi\bit\bt-\b-a\ban\bnd\bd-\b-e\bex\bxe\bec\bcu\but\bte\be-\b-c\bco\bom\bmm\bma\ban\bnd\bd (\b(C\bC-\b-x\bx C\bC-\b-e\be)\b)
- Invoke an editor on the current command line, and execute the
- result as shell commands. B\bBa\bas\bsh\bh attempts to invoke $\b$V\bVI\bIS\bSU\bUA\bAL\bL, $\b$E\bED\bDI\bI-\b-
- T\bTO\bOR\bR, and _\be_\bm_\ba_\bc_\bs as the editor, in that order.
+ Invoke an editor on the current command line, and execute the
+ result as shell commands. B\bBa\bas\bsh\bh attempts to invoke $\b$V\bVI\bIS\bSU\bUA\bAL\bL, $\b$E\bED\bD-\b-
+ I\bIT\bTO\bOR\bR, and _\be_\bm_\ba_\bc_\bs as the editor, in that order.
C\bCo\bom\bmm\bma\ban\bnd\bds\bs f\bfo\bor\br C\bCh\bha\ban\bng\bgi\bin\bng\bg T\bTe\bex\bxt\bt
_\be_\bn_\bd_\b-_\bo_\bf_\b-_\bf_\bi_\bl_\be (\b(u\bus\bsu\bua\bal\bll\bly\by C\bC-\b-d\bd)\b)
- The character indicating end-of-file as set, for example, by
- ``stty''. If this character is read when there are no characters
- on the line, and point is at the beginning of the line, readline
- interprets it as the end of input and returns E\bEO\bOF\bF.
+ The character indicating end-of-file as set, for example, by
+ ``stty''. If this character is read when there are no charac-
+ ters on the line, and point is at the beginning of the line,
+ readline interprets it as the end of input and returns E\bEO\bOF\bF.
d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br (\b(C\bC-\b-d\bd)\b)
- Delete the character at point. If this function is bound to the
+ Delete the character at point. If this function is bound to the
same character as the tty E\bEO\bOF\bF character, as C\bC-\b-d\bd commonly is, see
above for the effects.
b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br (\b(R\bRu\bub\bbo\bou\but\bt)\b)
- Delete the character behind the cursor. When given a numeric ar-
- gument, save the deleted text on the kill ring.
+ Delete the character behind the cursor. When given a numeric
+ argument, save the deleted text on the kill ring.
f\bfo\bor\brw\bwa\bar\brd\bd-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br
- Delete the character under the cursor, unless the cursor is at
+ Delete the character under the cursor, unless the cursor is at
the end of the line, in which case the character behind the cur-
sor is deleted.
q\bqu\buo\bot\bte\bed\bd-\b-i\bin\bns\bse\ber\brt\bt (\b(C\bC-\b-q\bq,\b, C\bC-\b-v\bv)\b)
- Add the next character typed to the line verbatim. This is how
+ Add the next character typed to the line verbatim. This is how
to insert characters like C\bC-\b-q\bq, for example.
t\bta\bab\bb-\b-i\bin\bns\bse\ber\brt\bt (\b(C\bC-\b-v\bv T\bTA\bAB\bB)\b)
Insert a tab character.
s\bse\bel\blf\bf-\b-i\bin\bns\bse\ber\brt\bt (\b(a\ba,\b, b\bb,\b, A\bA,\b, 1\b1,\b, !\b!,\b, .\b..\b..\b.)\b)
Insert the character typed.
t\btr\bra\ban\bns\bsp\bpo\bos\bse\be-\b-c\bch\bha\bar\brs\bs (\b(C\bC-\b-t\bt)\b)
- Drag the character before point forward over the character at
- point, moving point forward as well. If point is at the end of
- the line, then this transposes the two characters before point.
+ Drag the character before point forward over the character at
+ point, moving point forward as well. If point is at the end of
+ the line, then this transposes the two characters before point.
Negative arguments have no effect.
t\btr\bra\ban\bns\bsp\bpo\bos\bse\be-\b-w\bwo\bor\brd\bds\bs (\b(M\bM-\b-t\bt)\b)
- Drag the word before point past the word after point, moving
- point over that word as well. If point is at the end of the
+ Drag the word before point past the word after point, moving
+ point over that word as well. If point is at the end of the
line, this transposes the last two words on the line.
u\bup\bpc\bca\bas\bse\be-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-u\bu)\b)
- Uppercase the current (or following) word. With a negative argu-
- ment, uppercase the previous word, but do not move point.
+ Uppercase the current (or following) word. With a negative ar-
+ gument, uppercase the previous word, but do not move point.
d\bdo\bow\bwn\bnc\bca\bas\bse\be-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-l\bl)\b)
- Lowercase the current (or following) word. With a negative argu-
- ment, lowercase the previous word, but do not move point.
+ Lowercase the current (or following) word. With a negative ar-
+ gument, lowercase the previous word, but do not move point.
c\bca\bap\bpi\bit\bta\bal\bli\biz\bze\be-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-c\bc)\b)
- Capitalize the current (or following) word. With a negative ar-
+ Capitalize the current (or following) word. With a negative ar-
gument, capitalize the previous word, but do not move point.
o\bov\bve\ber\brw\bwr\bri\bit\bte\be-\b-m\bmo\bod\bde\be
- Toggle overwrite mode. With an explicit positive numeric argu-
- ment, switches to overwrite mode. With an explicit non-positive
- numeric argument, switches to insert mode. This command affects
- only e\bem\bma\bac\bcs\bs mode; v\bvi\bi mode does overwrite differently. Each call
- to _\br_\be_\ba_\bd_\bl_\bi_\bn_\be_\b(_\b) starts in insert mode. In overwrite mode, charac-
- ters bound to s\bse\bel\blf\bf-\b-i\bin\bns\bse\ber\brt\bt replace the text at point rather than
- pushing the text to the right. Characters bound to b\bba\bac\bck\bk-\b-
- w\bwa\bar\brd\bd-\b-d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br replace the character before point with a
- space. By default, this command is unbound.
+ Toggle overwrite mode. With an explicit positive numeric argu-
+ ment, switches to overwrite mode. With an explicit non-positive
+ numeric argument, switches to insert mode. This command affects
+ only e\bem\bma\bac\bcs\bs mode; v\bvi\bi mode does overwrite differently. Each call
+ to _\br_\be_\ba_\bd_\bl_\bi_\bn_\be_\b(_\b) starts in insert mode. In overwrite mode, charac-
+ ters bound to s\bse\bel\blf\bf-\b-i\bin\bns\bse\ber\brt\bt replace the text at point rather than
+ pushing the text to the right. Characters bound to b\bba\bac\bck\bk-\b-
+ w\bwa\bar\brd\bd-\b-d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br replace the character before point with a
+ space. By default, this command is unbound.
K\bKi\bil\bll\bli\bin\bng\bg a\ban\bnd\bd Y\bYa\ban\bnk\bki\bin\bng\bg
k\bki\bil\bll\bl-\b-l\bli\bin\bne\be (\b(C\bC-\b-k\bk)\b)
b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-k\bki\bil\bll\bl-\b-l\bli\bin\bne\be (\b(C\bC-\b-x\bx R\bRu\bub\bbo\bou\but\bt)\b)
Kill backward to the beginning of the line.
u\bun\bni\bix\bx-\b-l\bli\bin\bne\be-\b-d\bdi\bis\bsc\bca\bar\brd\bd (\b(C\bC-\b-u\bu)\b)
- Kill backward from point to the beginning of the line. The
+ Kill backward from point to the beginning of the line. The
killed text is saved on the kill-ring.
k\bki\bil\bll\bl-\b-w\bwh\bho\bol\ble\be-\b-l\bli\bin\bne\be
- Kill all characters on the current line, no matter where point
+ Kill all characters on the current line, no matter where point
is.
k\bki\bil\bll\bl-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-d\bd)\b)
- Kill from point to the end of the current word, or if between
- words, to the end of the next word. Word boundaries are the same
- as those used by f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
+ Kill from point to the end of the current word, or if between
+ words, to the end of the next word. Word boundaries are the
+ same as those used by f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-k\bki\bil\bll\bl-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-R\bRu\bub\bbo\bou\but\bt)\b)
- Kill the word behind point. Word boundaries are the same as
+ Kill the word behind point. Word boundaries are the same as
those used by b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
s\bsh\bhe\bel\bll\bl-\b-k\bki\bil\bll\bl-\b-w\bwo\bor\brd\bd
- Kill from point to the end of the current word, or if between
- words, to the end of the next word. Word boundaries are the same
- as those used by s\bsh\bhe\bel\bll\bl-\b-f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
+ Kill from point to the end of the current word, or if between
+ words, to the end of the next word. Word boundaries are the
+ same as those used by s\bsh\bhe\bel\bll\bl-\b-f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
s\bsh\bhe\bel\bll\bl-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-k\bki\bil\bll\bl-\b-w\bwo\bor\brd\bd
- Kill the word behind point. Word boundaries are the same as
+ Kill the word behind point. Word boundaries are the same as
those used by s\bsh\bhe\bel\bll\bl-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
u\bun\bni\bix\bx-\b-w\bwo\bor\brd\bd-\b-r\bru\bub\bbo\bou\but\bt (\b(C\bC-\b-w\bw)\b)
- Kill the word behind point, using white space as a word bound-
- ary. The killed text is saved on the kill-ring.
+ Kill the word behind point, using white space as a word bound-
+ ary. The killed text is saved on the kill-ring.
u\bun\bni\bix\bx-\b-f\bfi\bil\ble\ben\bna\bam\bme\be-\b-r\bru\bub\bbo\bou\but\bt
- Kill the word behind point, using white space and the slash
- character as the word boundaries. The killed text is saved on
+ Kill the word behind point, using white space and the slash
+ character as the word boundaries. The killed text is saved on
the kill-ring.
d\bde\bel\ble\bet\bte\be-\b-h\bho\bor\bri\biz\bzo\bon\bnt\bta\bal\bl-\b-s\bsp\bpa\bac\bce\be (\b(M\bM-\b-\\b\)\b)
Delete all spaces and tabs around point.
c\bco\bop\bpy\by-\b-r\bre\beg\bgi\bio\bon\bn-\b-a\bas\bs-\b-k\bki\bil\bll\bl
Copy the text in the region to the kill buffer.
c\bco\bop\bpy\by-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd
- Copy the word before point to the kill buffer. The word bound-
+ Copy the word before point to the kill buffer. The word bound-
aries are the same as b\bba\bac\bck\bkw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
c\bco\bop\bpy\by-\b-f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd
- Copy the word following point to the kill buffer. The word
+ Copy the word following point to the kill buffer. The word
boundaries are the same as f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
y\bya\ban\bnk\bk (\b(C\bC-\b-y\by)\b)
Yank the top of the kill ring into the buffer at point.
y\bya\ban\bnk\bk-\b-p\bpo\bop\bp (\b(M\bM-\b-y\by)\b)
- Rotate the kill ring, and yank the new top. Only works following
- y\bya\ban\bnk\bk or y\bya\ban\bnk\bk-\b-p\bpo\bop\bp.
+ Rotate the kill ring, and yank the new top. Only works follow-
+ ing y\bya\ban\bnk\bk or y\bya\ban\bnk\bk-\b-p\bpo\bop\bp.
N\bNu\bum\bme\ber\bri\bic\bc A\bAr\brg\bgu\bum\bme\ben\bnt\bts\bs
d\bdi\big\bgi\bit\bt-\b-a\bar\brg\bgu\bum\bme\ben\bnt\bt (\b(M\bM-\b-0\b0,\b, M\bM-\b-1\b1,\b, .\b..\b..\b.,\b, M\bM-\b--\b-)\b)
- Add this digit to the argument already accumulating, or start a
- new argument. M-- starts a negative argument.
+ Add this digit to the argument already accumulating, or start a
+ new argument. M-- starts a negative argument.
u\bun\bni\biv\bve\ber\brs\bsa\bal\bl-\b-a\bar\brg\bgu\bum\bme\ben\bnt\bt
- This is another way to specify an argument. If this command is
- followed by one or more digits, optionally with a leading minus
- sign, those digits define the argument. If the command is fol-
+ This is another way to specify an argument. If this command is
+ followed by one or more digits, optionally with a leading minus
+ sign, those digits define the argument. If the command is fol-
lowed by digits, executing u\bun\bni\biv\bve\ber\brs\bsa\bal\bl-\b-a\bar\brg\bgu\bum\bme\ben\bnt\bt again ends the nu-
- meric argument, but is otherwise ignored. As a special case, if
+ meric argument, but is otherwise ignored. As a special case, if
this command is immediately followed by a character that is nei-
- ther a digit nor minus sign, the argument count for the next
- command is multiplied by four. The argument count is initially
- one, so executing this function the first time makes the argu-
+ ther a digit nor minus sign, the argument count for the next
+ command is multiplied by four. The argument count is initially
+ one, so executing this function the first time makes the argu-
ment count four, a second time makes the argument count sixteen,
and so on.
C\bCo\bom\bmp\bpl\ble\bet\bti\bin\bng\bg
c\bco\bom\bmp\bpl\ble\bet\bte\be (\b(T\bTA\bAB\bB)\b)
- Attempt to perform completion on the text before point. B\bBa\bas\bsh\bh at-
- tempts completion treating the text as a variable (if the text
- begins with $\b$), username (if the text begins with ~\b~), hostname
- (if the text begins with @\b@), or command (including aliases and
- functions) in turn. If none of these produces a match, filename
+ Attempt to perform completion on the text before point. B\bBa\bas\bsh\bh
+ attempts completion treating the text as a variable (if the text
+ begins with $\b$), username (if the text begins with ~\b~), hostname
+ (if the text begins with @\b@), or command (including aliases and
+ functions) in turn. If none of these produces a match, filename
completion is attempted.
p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs (\b(M\bM-\b-?\b?)\b)
List the possible completions of the text before point.
i\bin\bns\bse\ber\brt\bt-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs (\b(M\bM-\b-*\b*)\b)
- Insert all completions of the text before point that would have
+ Insert all completions of the text before point that would have
been generated by p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs.
m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be
- Similar to c\bco\bom\bmp\bpl\ble\bet\bte\be, but replaces the word to be completed with
- a single match from the list of possible completions. Repeated
- execution of m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be steps through the list of possible
- completions, inserting each match in turn. At the end of the
+ Similar to c\bco\bom\bmp\bpl\ble\bet\bte\be, but replaces the word to be completed with
+ a single match from the list of possible completions. Repeated
+ execution of m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be steps through the list of possible
+ completions, inserting each match in turn. At the end of the
list of completions, the bell is rung (subject to the setting of
- b\bbe\bel\bll\bl-\b-s\bst\bty\byl\ble\be) and the original text is restored. An argument of _\bn
+ b\bbe\bel\bll\bl-\b-s\bst\bty\byl\ble\be) and the original text is restored. An argument of _\bn
moves _\bn positions forward in the list of matches; a negative ar-
- gument may be used to move backward through the list. This com-
+ gument may be used to move backward through the list. This com-
mand is intended to be bound to T\bTA\bAB\bB, but is unbound by default.
m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd
- Identical to m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be, but moves backward through the list
- of possible completions, as if m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be had been given a
- negative argument. This command is unbound by default.
+ Identical to m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be, but moves backward through the list
+ of possible completions, as if m\bme\ben\bnu\bu-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be had been given a
+ negative argument. This command is unbound by default.
d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br-\b-o\bor\br-\b-l\bli\bis\bst\bt
- Deletes the character under the cursor if not at the beginning
- or end of the line (like d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br). If at the end of the
- line, behaves identically to p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs. This command
+ Deletes the character under the cursor if not at the beginning
+ or end of the line (like d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br). If at the end of the
+ line, behaves identically to p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs. This command
is unbound by default.
c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-f\bfi\bil\ble\ben\bna\bam\bme\be (\b(M\bM-\b-/\b/)\b)
Attempt filename completion on the text before point.
List the possible completions of the text before point, treating
it as a filename.
c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-u\bus\bse\ber\brn\bna\bam\bme\be (\b(M\bM-\b-~\b~)\b)
- Attempt completion on the text before point, treating it as a
+ Attempt completion on the text before point, treating it as a
username.
p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-u\bus\bse\ber\brn\bna\bam\bme\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs (\b(C\bC-\b-x\bx ~\b~)\b)
List the possible completions of the text before point, treating
it as a username.
c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-v\bva\bar\bri\bia\bab\bbl\ble\be (\b(M\bM-\b-$\b$)\b)
- Attempt completion on the text before point, treating it as a
+ Attempt completion on the text before point, treating it as a
shell variable.
p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-v\bva\bar\bri\bia\bab\bbl\ble\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs (\b(C\bC-\b-x\bx $\b$)\b)
List the possible completions of the text before point, treating
it as a shell variable.
c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-h\bho\bos\bst\btn\bna\bam\bme\be (\b(M\bM-\b-@\b@)\b)
- Attempt completion on the text before point, treating it as a
+ Attempt completion on the text before point, treating it as a
hostname.
p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-h\bho\bos\bst\btn\bna\bam\bme\be-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs (\b(C\bC-\b-x\bx @\b@)\b)
List the possible completions of the text before point, treating
it as a hostname.
c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-c\bco\bom\bmm\bma\ban\bnd\bd (\b(M\bM-\b-!\b!)\b)
- Attempt completion on the text before point, treating it as a
- command name. Command completion attempts to match the text
- against aliases, reserved words, shell functions, shell
+ Attempt completion on the text before point, treating it as a
+ command name. Command completion attempts to match the text
+ against aliases, reserved words, shell functions, shell
builtins, and finally executable filenames, in that order.
p\bpo\bos\bss\bsi\bib\bbl\ble\be-\b-c\bco\bom\bmm\bma\ban\bnd\bd-\b-c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bns\bs (\b(C\bC-\b-x\bx !\b!)\b)
List the possible completions of the text before point, treating
it as a command name.
d\bdy\byn\bna\bam\bmi\bic\bc-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-h\bhi\bis\bst\bto\bor\bry\by (\b(M\bM-\b-T\bTA\bAB\bB)\b)
- Attempt completion on the text before point, comparing the text
- against lines from the history list for possible completion
+ Attempt completion on the text before point, comparing the text
+ against lines from the history list for possible completion
matches.
d\bda\bab\bbb\bbr\bre\bev\bv-\b-e\bex\bxp\bpa\ban\bnd\bd
- Attempt menu completion on the text before point, comparing the
+ Attempt menu completion on the text before point, comparing the
text against lines from the history list for possible completion
matches.
c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-i\bin\bnt\bto\bo-\b-b\bbr\bra\bac\bce\bes\bs (\b(M\bM-\b-{\b{)\b)
Perform filename completion and insert the list of possible com-
- pletions enclosed within braces so the list is available to the
+ pletions enclosed within braces so the list is available to the
shell (see B\bBr\bra\bac\bce\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn above).
K\bKe\bey\byb\bbo\boa\bar\brd\bd M\bMa\bac\bcr\bro\bos\bs
s\bst\bta\bar\brt\bt-\b-k\bkb\bbd\bd-\b-m\bma\bac\bcr\bro\bo (\b(C\bC-\b-x\bx (\b()\b)
- Begin saving the characters typed into the current keyboard
+ Begin saving the characters typed into the current keyboard
macro.
e\ben\bnd\bd-\b-k\bkb\bbd\bd-\b-m\bma\bac\bcr\bro\bo (\b(C\bC-\b-x\bx )\b))\b)
Stop saving the characters typed into the current keyboard macro
and store the definition.
c\bca\bal\bll\bl-\b-l\bla\bas\bst\bt-\b-k\bkb\bbd\bd-\b-m\bma\bac\bcr\bro\bo (\b(C\bC-\b-x\bx e\be)\b)
- Re-execute the last keyboard macro defined, by making the char-
+ Re-execute the last keyboard macro defined, by making the char-
acters in the macro appear as if typed at the keyboard.
p\bpr\bri\bin\bnt\bt-\b-l\bla\bas\bst\bt-\b-k\bkb\bbd\bd-\b-m\bma\bac\bcr\bro\bo (\b()\b)
- Print the last keyboard macro defined in a format suitable for
+ Print the last keyboard macro defined in a format suitable for
the _\bi_\bn_\bp_\bu_\bt_\br_\bc file.
M\bMi\bis\bsc\bce\bel\bll\bla\ban\bne\beo\bou\bus\bs
r\bre\be-\b-r\bre\bea\bad\bd-\b-i\bin\bni\bit\bt-\b-f\bfi\bil\ble\be (\b(C\bC-\b-x\bx C\bC-\b-r\br)\b)
- Read in the contents of the _\bi_\bn_\bp_\bu_\bt_\br_\bc file, and incorporate any
+ Read in the contents of the _\bi_\bn_\bp_\bu_\bt_\br_\bc file, and incorporate any
bindings or variable assignments found there.
a\bab\bbo\bor\brt\bt (\b(C\bC-\b-g\bg)\b)
- Abort the current editing command and ring the terminal's bell
+ Abort the current editing command and ring the terminal's bell
(subject to the setting of b\bbe\bel\bll\bl-\b-s\bst\bty\byl\ble\be).
d\bdo\bo-\b-l\blo\bow\bwe\ber\brc\bca\bas\bse\be-\b-v\bve\ber\brs\bsi\bio\bon\bn (\b(M\bM-\b-A\bA,\b, M\bM-\b-B\bB,\b, M\bM-\b-_\bx,\b, .\b..\b..\b.)\b)
- If the metafied character _\bx is uppercase, run the command that
+ If the metafied character _\bx is uppercase, run the command that
is bound to the corresponding metafied lowercase character. The
behavior is undefined if _\bx is already lowercase.
p\bpr\bre\bef\bfi\bix\bx-\b-m\bme\bet\bta\ba (\b(E\bES\bSC\bC)\b)
- Metafy the next character typed. E\bES\bSC\bC f\bf is equivalent to M\bMe\bet\bta\ba-\b-f\bf.
+ Metafy the next character typed. E\bES\bSC\bC f\bf is equivalent to M\bMe\bet\bta\ba-\b-f\bf.
u\bun\bnd\bdo\bo (\b(C\bC-\b-_\b_,\b, C\bC-\b-x\bx C\bC-\b-u\bu)\b)
Incremental undo, separately remembered for each line.
r\bre\bev\bve\ber\brt\bt-\b-l\bli\bin\bne\be (\b(M\bM-\b-r\br)\b)
- Undo all changes made to this line. This is like executing the
- u\bun\bnd\bdo\bo command enough times to return the line to its initial
+ Undo all changes made to this line. This is like executing the
+ u\bun\bnd\bdo\bo command enough times to return the line to its initial
state.
t\bti\bil\bld\bde\be-\b-e\bex\bxp\bpa\ban\bnd\bd (\b(M\bM-\b-&\b&)\b)
Perform tilde expansion on the current word.
s\bse\bet\bt-\b-m\bma\bar\brk\bk (\b(C\bC-\b-@\b@,\b, M\bM-\b-<\b<s\bsp\bpa\bac\bce\be>\b>)\b)
- Set the mark to the point. If a numeric argument is supplied,
+ Set the mark to the point. If a numeric argument is supplied,
the mark is set to that position.
e\bex\bxc\bch\bha\ban\bng\bge\be-\b-p\bpo\boi\bin\bnt\bt-\b-a\ban\bnd\bd-\b-m\bma\bar\brk\bk (\b(C\bC-\b-x\bx C\bC-\b-x\bx)\b)
- Swap the point with the mark. The current cursor position is set
- to the saved position, and the old cursor position is saved as
- the mark.
+ Swap the point with the mark. The current cursor position is
+ set to the saved position, and the old cursor position is saved
+ as the mark.
c\bch\bha\bar\bra\bac\bct\bte\ber\br-\b-s\bse\bea\bar\brc\bch\bh (\b(C\bC-\b-]\b])\b)
A character is read and point is moved to the next occurrence of
- that character. A negative argument searches for previous occur-
- rences.
+ that character. A negative argument searches for previous oc-
+ currences.
c\bch\bha\bar\bra\bac\bct\bte\ber\br-\b-s\bse\bea\bar\brc\bch\bh-\b-b\bba\bac\bck\bkw\bwa\bar\brd\bd (\b(M\bM-\b-C\bC-\b-]\b])\b)
- A character is read and point is moved to the previous occur-
- rence of that character. A negative argument searches for subse-
- quent occurrences.
+ A character is read and point is moved to the previous occur-
+ rence of that character. A negative argument searches for sub-
+ sequent occurrences.
s\bsk\bki\bip\bp-\b-c\bcs\bsi\bi-\b-s\bse\beq\bqu\bue\ben\bnc\bce\be
- Read enough characters to consume a multi-key sequence such as
- those defined for keys like Home and End. Such sequences begin
- with a Control Sequence Indicator (CSI), usually ESC-[. If this
- sequence is bound to "\[", keys producing such sequences will
- have no effect unless explicitly bound to a readline command,
- instead of inserting stray characters into the editing buffer.
+ Read enough characters to consume a multi-key sequence such as
+ those defined for keys like Home and End. Such sequences begin
+ with a Control Sequence Indicator (CSI), usually ESC-[. If this
+ sequence is bound to "\[", keys producing such sequences will
+ have no effect unless explicitly bound to a readline command,
+ instead of inserting stray characters into the editing buffer.
This is unbound by default, but usually bound to ESC-[.
i\bin\bns\bse\ber\brt\bt-\b-c\bco\bom\bmm\bme\ben\bnt\bt (\b(M\bM-\b-#\b#)\b)
- Without a numeric argument, the value of the readline c\bco\bom\bm-\b-
- m\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn variable is inserted at the beginning of the current
- line. If a numeric argument is supplied, this command acts as a
- toggle: if the characters at the beginning of the line do not
- match the value of c\bco\bom\bmm\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn, the value is inserted, other-
+ Without a numeric argument, the value of the readline c\bco\bom\bm-\b-
+ m\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn variable is inserted at the beginning of the current
+ line. If a numeric argument is supplied, this command acts as a
+ toggle: if the characters at the beginning of the line do not
+ match the value of c\bco\bom\bmm\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn, the value is inserted, other-
wise the characters in c\bco\bom\bmm\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn are deleted from the begin-
- ning of the line. In either case, the line is accepted as if a
- newline had been typed. The default value of c\bco\bom\bmm\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn
- causes this command to make the current line a shell comment. If
- a numeric argument causes the comment character to be removed,
- the line will be executed by the shell.
+ ning of the line. In either case, the line is accepted as if a
+ newline had been typed. The default value of c\bco\bom\bmm\bme\ben\bnt\bt-\b-b\bbe\beg\bgi\bin\bn
+ causes this command to make the current line a shell comment.
+ If a numeric argument causes the comment character to be re-
+ moved, the line will be executed by the shell.
s\bsp\bpe\bel\bll\bl-\b-c\bco\bor\brr\bre\bec\bct\bt-\b-w\bwo\bor\brd\bd (\b(C\bC-\b-x\bx s\bs)\b)
- Perform spelling correction on the current word, treating it as
- a directory or filename, in the same way as the c\bcd\bds\bsp\bpe\bel\bll\bl shell
- option. Word boundaries are the same as those used by s\bsh\bhe\bel\bll\bl-\b-f\bfo\bor\br-\b-
- w\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
+ Perform spelling correction on the current word, treating it as
+ a directory or filename, in the same way as the c\bcd\bds\bsp\bpe\bel\bll\bl shell
+ option. Word boundaries are the same as those used by
+ s\bsh\bhe\bel\bll\bl-\b-f\bfo\bor\brw\bwa\bar\brd\bd-\b-w\bwo\bor\brd\bd.
g\bgl\blo\bob\bb-\b-c\bco\bom\bmp\bpl\ble\bet\bte\be-\b-w\bwo\bor\brd\bd (\b(M\bM-\b-g\bg)\b)
- The word before point is treated as a pattern for pathname ex-
- pansion, with an asterisk implicitly appended. This pattern is
- used to generate a list of matching filenames for possible com-
+ The word before point is treated as a pattern for pathname ex-
+ pansion, with an asterisk implicitly appended. This pattern is
+ used to generate a list of matching filenames for possible com-
pletions.
g\bgl\blo\bob\bb-\b-e\bex\bxp\bpa\ban\bnd\bd-\b-w\bwo\bor\brd\bd (\b(C\bC-\b-x\bx *\b*)\b)
- The word before point is treated as a pattern for pathname ex-
+ The word before point is treated as a pattern for pathname ex-
pansion, and the list of matching filenames is inserted, replac-
- ing the word. If a numeric argument is supplied, an asterisk is
+ ing the word. If a numeric argument is supplied, an asterisk is
appended before pathname expansion.
g\bgl\blo\bob\bb-\b-l\bli\bis\bst\bt-\b-e\bex\bxp\bpa\ban\bns\bsi\bio\bon\bns\bs (\b(C\bC-\b-x\bx g\bg)\b)
- The list of expansions that would have been generated by
- g\bgl\blo\bob\bb-\b-e\bex\bxp\bpa\ban\bnd\bd-\b-w\bwo\bor\brd\bd is displayed, and the line is redrawn. If a nu-
- meric argument is supplied, an asterisk is appended before path-
- name expansion.
+ The list of expansions that would have been generated by
+ g\bgl\blo\bob\bb-\b-e\bex\bxp\bpa\ban\bnd\bd-\b-w\bwo\bor\brd\bd is displayed, and the line is redrawn. If a
+ numeric argument is supplied, an asterisk is appended before
+ pathname expansion.
d\bdu\bum\bmp\bp-\b-f\bfu\bun\bnc\bct\bti\bio\bon\bns\bs
- Print all of the functions and their key bindings to the read-
- line output stream. If a numeric argument is supplied, the out-
- put is formatted in such a way that it can be made part of an
+ Print all of the functions and their key bindings to the read-
+ line output stream. If a numeric argument is supplied, the out-
+ put is formatted in such a way that it can be made part of an
_\bi_\bn_\bp_\bu_\bt_\br_\bc file.
d\bdu\bum\bmp\bp-\b-v\bva\bar\bri\bia\bab\bbl\ble\bes\bs
Print all of the settable readline variables and their values to
- the readline output stream. If a numeric argument is supplied,
- the output is formatted in such a way that it can be made part
+ the readline output stream. If a numeric argument is supplied,
+ the output is formatted in such a way that it can be made part
of an _\bi_\bn_\bp_\bu_\bt_\br_\bc file.
d\bdu\bum\bmp\bp-\b-m\bma\bac\bcr\bro\bos\bs
- Print all of the readline key sequences bound to macros and the
- strings they output. If a numeric argument is supplied, the out-
- put is formatted in such a way that it can be made part of an
+ Print all of the readline key sequences bound to macros and the
+ strings they output. If a numeric argument is supplied, the
+ output is formatted in such a way that it can be made part of an
_\bi_\bn_\bp_\bu_\bt_\br_\bc file.
d\bdi\bis\bsp\bpl\bla\bay\by-\b-s\bsh\bhe\bel\bll\bl-\b-v\bve\ber\brs\bsi\bio\bon\bn (\b(C\bC-\b-x\bx C\bC-\b-v\bv)\b)
Display version information about the current instance of b\bba\bas\bsh\bh.
P\bPr\bro\bog\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn
- When word completion is attempted for an argument to a command for
- which a completion specification (a _\bc_\bo_\bm_\bp_\bs_\bp_\be_\bc) has been defined using
- the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below), the program-
+ When word completion is attempted for an argument to a command for
+ which a completion specification (a _\bc_\bo_\bm_\bp_\bs_\bp_\be_\bc) has been defined using
+ the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below), the program-
mable completion facilities are invoked.
- First, the command name is identified. If the command word is the empty
- string (completion attempted at the beginning of an empty line), any
- compspec defined with the -\b-E\bE option to c\bco\bom\bmp\bpl\ble\bet\bte\be is used. If a compspec
- has been defined for that command, the compspec is used to generate the
- list of possible completions for the word. If the command word is a
- full pathname, a compspec for the full pathname is searched for first.
- If no compspec is found for the full pathname, an attempt is made to
- find a compspec for the portion following the final slash. If those
- searches do not result in a compspec, any compspec defined with the -\b-D\bD
- option to c\bco\bom\bmp\bpl\ble\bet\bte\be is used as the default. If there is no default comp-
- spec, b\bba\bas\bsh\bh attempts alias expansion on the command word as a final re-
- sort, and attempts to find a compspec for the command word from any
- successful expansion.
-
- Once a compspec has been found, it is used to generate the list of
- matching words. If a compspec is not found, the default b\bba\bas\bsh\bh completion
- as described above under C\bCo\bom\bmp\bpl\ble\bet\bti\bin\bng\bg is performed.
-
- First, the actions specified by the compspec are used. Only matches
- which are prefixed by the word being completed are returned. When the
- -\b-f\bf or -\b-d\bd option is used for filename or directory name completion, the
+ First, the command name is identified. If the command word is the
+ empty string (completion attempted at the beginning of an empty line),
+ any compspec defined with the -\b-E\bE option to c\bco\bom\bmp\bpl\ble\bet\bte\be is used. If a
+ compspec has been defined for that command, the compspec is used to
+ generate the list of possible completions for the word. If the command
+ word is a full pathname, a compspec for the full pathname is searched
+ for first. If no compspec is found for the full pathname, an attempt
+ is made to find a compspec for the portion following the final slash.
+ If those searches do not result in a compspec, any compspec defined
+ with the -\b-D\bD option to c\bco\bom\bmp\bpl\ble\bet\bte\be is used as the default. If there is no
+ default compspec, b\bba\bas\bsh\bh attempts alias expansion on the command word as
+ a final resort, and attempts to find a compspec for the command word
+ from any successful expansion.
+
+ Once a compspec has been found, it is used to generate the list of
+ matching words. If a compspec is not found, the default b\bba\bas\bsh\bh comple-
+ tion as described above under C\bCo\bom\bmp\bpl\ble\bet\bti\bin\bng\bg is performed.
+
+ First, the actions specified by the compspec are used. Only matches
+ which are prefixed by the word being completed are returned. When the
+ -\b-f\bf or -\b-d\bd option is used for filename or directory name completion, the
shell variable F\bFI\bIG\bGN\bNO\bOR\bRE\bE is used to filter the matches.
Any completions specified by a pathname expansion pattern to the -\b-G\bG op-
- tion are generated next. The words generated by the pattern need not
- match the word being completed. The G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE shell variable is not
+ tion are generated next. The words generated by the pattern need not
+ match the word being completed. The G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE shell variable is not
used to filter the matches, but the F\bFI\bIG\bGN\bNO\bOR\bRE\bE variable is used.
- Next, the string specified as the argument to the -\b-W\bW option is consid-
- ered. The string is first split using the characters in the I\bIF\bFS\bS special
- variable as delimiters. Shell quoting is honored. Each word is then ex-
- panded using brace expansion, tilde expansion, parameter and variable
- expansion, command substitution, and arithmetic expansion, as described
- above under E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN. The results are split using the rules described
- above under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg. The results of the expansion are prefix-
- matched against the word being completed, and the matching words become
- the possible completions.
-
- After these matches have been generated, any shell function or command
- specified with the -\b-F\bF and -\b-C\bC options is invoked. When the command or
+ Next, the string specified as the argument to the -\b-W\bW option is consid-
+ ered. The string is first split using the characters in the I\bIF\bFS\bS spe-
+ cial variable as delimiters. Shell quoting is honored. Each word is
+ then expanded using brace expansion, tilde expansion, parameter and
+ variable expansion, command substitution, and arithmetic expansion, as
+ described above under E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN. The results are split using the rules
+ described above under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg. The results of the expansion are
+ prefix-matched against the word being completed, and the matching words
+ become the possible completions.
+
+ After these matches have been generated, any shell function or command
+ specified with the -\b-F\bF and -\b-C\bC options is invoked. When the command or
function is invoked, the C\bCO\bOM\bMP\bP_\b_L\bLI\bIN\bNE\bE, C\bCO\bOM\bMP\bP_\b_P\bPO\bOI\bIN\bNT\bT, C\bCO\bOM\bMP\bP_\b_K\bKE\bEY\bY, and C\bCO\bOM\bMP\bP_\b_T\bTY\bYP\bPE\bE
variables are assigned values as described above under S\bSh\bhe\bel\bll\bl V\bVa\bar\bri\bia\bab\bbl\ble\bes\bs.
- If a shell function is being invoked, the C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDS\bS and C\bCO\bOM\bMP\bP_\b_C\bCW\bWO\bOR\bRD\bD
- variables are also set. When the function or command is invoked, the
- first argument ($\b$1\b1) is the name of the command whose arguments are be-
- ing completed, the second argument ($\b$2\b2) is the word being completed,
- and the third argument ($\b$3\b3) is the word preceding the word being com-
- pleted on the current command line. No filtering of the generated com-
+ If a shell function is being invoked, the C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDS\bS and C\bCO\bOM\bMP\bP_\b_C\bCW\bWO\bOR\bRD\bD
+ variables are also set. When the function or command is invoked, the
+ first argument ($\b$1\b1) is the name of the command whose arguments are be-
+ ing completed, the second argument ($\b$2\b2) is the word being completed,
+ and the third argument ($\b$3\b3) 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 -\b-F\bF is invoked first. The function may use
- any of the shell facilities, including the c\bco\bom\bmp\bpg\bge\ben\bn builtin described
- below, to generate the matches. It must put the possible completions in
- the C\bCO\bOM\bMP\bPR\bRE\bEP\bPL\bLY\bY array variable, one per array element.
+ Any function specified with -\b-F\bF is invoked first. The function may use
+ any of the shell facilities, including the c\bco\bom\bmp\bpg\bge\ben\bn builtin described
+ below, to generate the matches. It must put the possible completions
+ in the C\bCO\bOM\bMP\bPR\bRE\bEP\bPL\bLY\bY array variable, one per array element.
- Next, any command specified with the -\b-C\bC option is invoked in an envi-
- ronment equivalent to command substitution. It should print a list of
- completions, one per line, to the standard output. Backslash may be
+ Next, any command specified with the -\b-C\bC option is invoked in an envi-
+ ronment equivalent to command substitution. It should print a list of
+ completions, one per line, to the standard output. Backslash may be
used to escape a newline, if necessary.
- After all of the possible completions are generated, any filter speci-
- fied with the -\b-X\bX option is applied to the list. The filter is a pattern
- as used for pathname expansion; a &\b& in the pattern is replaced with the
- text of the word being completed. A literal &\b& may be escaped with a
- backslash; the backslash is removed before attempting a match. Any com-
- pletion that matches the pattern will be removed from the list. A lead-
- ing !\b! negates the pattern; in this case any completion not matching the
- pattern will be removed. If the n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh shell option is enabled,
- the match is performed without regard to the case of alphabetic charac-
- ters.
+ After all of the possible completions are generated, any filter speci-
+ fied with the -\b-X\bX option is applied to the list. The filter is a pat-
+ tern as used for pathname expansion; a &\b& in the pattern is replaced
+ with the text of the word being completed. A literal &\b& may be escaped
+ with a backslash; the backslash is removed before attempting a match.
+ Any completion that matches the pattern will be removed from the list.
+ A leading !\b! negates the pattern; in this case any completion not match-
+ ing the pattern will be removed. If the n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh shell option is
+ enabled, the match is performed without regard to the case of alpha-
+ betic characters.
Finally, any prefix and suffix specified with the -\b-P\bP and -\b-S\bS options are
added to each member of the completion list, and the result is returned
to the readline completion code as the list of possible completions.
- If the previously-applied actions do not generate any matches, and the
- -\b-o\bo d\bdi\bir\brn\bna\bam\bme\bes\bs option was supplied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec was de-
+ If the previously-applied actions do not generate any matches, and the
+ -\b-o\bo d\bdi\bir\brn\bna\bam\bme\bes\bs option was supplied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec was de-
fined, directory name completion is attempted.
- If the -\b-o\bo p\bpl\blu\bus\bsd\bdi\bir\brs\bs option was supplied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec
+ If the -\b-o\bo p\bpl\blu\bus\bsd\bdi\bir\brs\bs option was supplied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec
was defined, directory name completion is attempted and any matches are
added to the results of the other actions.
- By default, if a compspec is found, whatever it generates is returned
- to the completion code as the full set of possible completions. The de-
- fault b\bba\bas\bsh\bh completions are not attempted, and the readline default of
- filename completion is disabled. If the -\b-o\bo b\bba\bas\bsh\bhd\bde\bef\bfa\bau\bul\blt\bt option was sup-
- plied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec was defined, the b\bba\bas\bsh\bh default com-
- pletions are attempted if the compspec generates no matches. If the -\b-o\bo
- d\bde\bef\bfa\bau\bul\blt\bt option was supplied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec was defined,
- readline's default completion will be performed if the compspec (and,
+ By default, if a compspec is found, whatever it generates is returned
+ to the completion code as the full set of possible completions. The
+ default b\bba\bas\bsh\bh completions are not attempted, and the readline default of
+ filename completion is disabled. If the -\b-o\bo b\bba\bas\bsh\bhd\bde\bef\bfa\bau\bul\blt\bt option was sup-
+ plied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec was defined, the b\bba\bas\bsh\bh default com-
+ pletions are attempted if the compspec generates no matches. If the -\b-o\bo
+ d\bde\bef\bfa\bau\bul\blt\bt option was supplied to c\bco\bom\bmp\bpl\ble\bet\bte\be when the compspec was defined,
+ readline's default completion will be performed if the compspec (and,
if attempted, the default b\bba\bas\bsh\bh completions) generate no matches.
- When a compspec indicates that directory name completion is desired,
- the programmable completion functions force readline to append a slash
- to completed names which are symbolic links to directories, subject to
- the value of the m\bma\bar\brk\bk-\b-d\bdi\bir\bre\bec\bct\bto\bor\bri\bie\bes\bs readline variable, regardless of the
+ When a compspec indicates that directory name completion is desired,
+ the programmable completion functions force readline to append a slash
+ to completed names which are symbolic links to directories, subject to
+ the value of the m\bma\bar\brk\bk-\b-d\bdi\bir\bre\bec\bct\bto\bor\bri\bie\bes\bs readline variable, regardless of the
setting of the m\bma\bar\brk\bk-\b-s\bsy\bym\bml\bli\bin\bnk\bke\bed\bd-\b-d\bdi\bir\bre\bec\bct\bto\bor\bri\bie\bes\bs readline variable.
- There is some support for dynamically modifying completions. This is
- most useful when used in combination with a default completion speci-
- fied with c\bco\bom\bmp\bpl\ble\bet\bte\be -\b-D\bD. It's possible for shell functions executed as
- completion handlers to indicate that completion should be retried by
- returning an exit status of 124. If a shell function returns 124, and
+ There is some support for dynamically modifying completions. This is
+ most useful when used in combination with a default completion speci-
+ fied with c\bco\bom\bmp\bpl\ble\bet\bte\be -\b-D\bD. It's possible for shell functions executed as
+ completion handlers to indicate that completion should be retried by
+ returning an exit status of 124. If a shell function returns 124, and
changes the compspec associated with the command on which completion is
- being attempted (supplied as the first argument when the function is
+ being attempted (supplied as the first argument when the function is
executed), programmable completion restarts from the beginning, with an
- attempt to find a new compspec for that command. This allows a set of
- completions to be built dynamically as completion is attempted, rather
+ attempt to find a new compspec for that command. This allows a set of
+ completions to be built dynamically as completion is attempted, rather
than being loaded all at once.
- For instance, assuming that there is a library of compspecs, each kept
- in a file corresponding to the name of the command, the following de-
+ For instance, assuming that there is a library of compspecs, each kept
+ in a file corresponding to the name of the command, the following de-
fault completion function would load completions dynamically:
_completion_loader()
H\bHI\bIS\bST\bTO\bOR\bRY\bY
- When the -\b-o\bo h\bhi\bis\bst\bto\bor\bry\by option to the s\bse\bet\bt builtin is enabled, the shell
+ When the -\b-o\bo h\bhi\bis\bst\bto\bor\bry\by option to the s\bse\bet\bt builtin is enabled, the shell
provides access to the _\bc_\bo_\bm_\bm_\ba_\bn_\bd _\bh_\bi_\bs_\bt_\bo_\br_\by, the list of commands previously
- typed. The value of the H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE variable is used as the number of com-
- mands to save in a history list. The text of the last H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE commands
- (default 500) is saved. The shell stores each command in the history
- list prior to parameter and variable expansion (see E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN above)
- but after history expansion is performed, subject to the values of the
- shell variables H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE and H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL.
+ typed. The value of the H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE variable is used as the number of
+ commands to save in a history list. The text of the last H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE com-
+ mands (default 500) is saved. The shell stores each command in the
+ history list prior to parameter and variable expansion (see E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN
+ above) but after history expansion is performed, subject to the values
+ of the shell variables H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE and H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL.
On startup, the history is initialized from the file named by the vari-
- able H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE (default _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bh_\bi_\bs_\bt_\bo_\br_\by). The file named by the value of
- H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is truncated, if necessary, to contain no more than the number
- of lines specified by the value of H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE. If H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE is un-
- set, 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 followed immediately
- by a digit are interpreted as timestamps for the following history
- line. These timestamps are optionally displayed depending on the value
- of the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable. When a shell with history enabled ex-
- its, the last $\b$H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE lines are copied from the history list to
- $\b$H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE. If the h\bhi\bis\bst\bta\bap\bpp\bpe\ben\bnd\bd shell option is enabled (see the descrip-
- tion of s\bsh\bho\bop\bpt\bt under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below), the lines are ap-
- pended to the history file, otherwise the history file is overwritten.
- If H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is unset or null, or if the history file is unwritable, the
- history is not saved. If the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT 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 H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE lines. If H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE 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 f\bfc\bc (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below) may be used
- to list or edit and re-execute a portion of the history list. The h\bhi\bis\bs-\b-
- t\bto\bor\bry\by builtin may be used to display or modify the history list and ma-
- nipulate the history file. When using command-line editing, search com-
- mands are available in each editing mode that provide access to the
+ able H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE (default _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bh_\bi_\bs_\bt_\bo_\br_\by). The file named by the value
+ of H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is truncated, if necessary, to contain no more than the
+ number of lines specified by the value of H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE. If H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE-\b-
+ S\bSI\bIZ\bZE\bE 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 fol-
+ lowing history line. These timestamps are optionally displayed depend-
+ ing on the value of the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable. When a shell with
+ history enabled exits, the last $\b$H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE lines are copied from the
+ history list to $\b$H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE. If the h\bhi\bis\bst\bta\bap\bpp\bpe\ben\bnd\bd shell option is enabled
+ (see the description of s\bsh\bho\bop\bpt\bt under S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below), the
+ lines are appended to the history file, otherwise the history file is
+ overwritten. If H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is unset or null, or if the history file is
+ unwritable, the history is not saved. If the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable
+ is set, time stamps are written to the history file, marked with the
+ history comment character, so they may be preserved across shell ses-
+ sions. This uses the history comment character to distinguish time-
+ stamps from other history lines. After saving the history, the history
+ file is truncated to contain no more than H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE lines. If H\bHI\bIS\bST\bT-\b-
+ F\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE 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 f\bfc\bc (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below) may be used
+ to list or edit and re-execute a portion of the history list. The h\bhi\bis\bs-\b-
+ t\bto\bor\bry\by builtin may be used to display or modify the history list and ma-
+ nipulate 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
- list. The H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL and H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE variables are used to cause the
- shell to save only a subset of the commands entered. The c\bcm\bmd\bdh\bhi\bis\bst\bt 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 l\bli\bit\bth\bhi\bis\bst\bt shell option
- causes the shell to save the command with embedded newlines instead of
+ The shell allows control over which commands are saved on the history
+ list. The H\bHI\bIS\bST\bTC\bCO\bON\bNT\bTR\bRO\bOL\bL and H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE variables are used to cause the
+ shell to save only a subset of the commands entered. The c\bcm\bmd\bdh\bhi\bis\bst\bt 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 l\bli\bit\bth\bhi\bis\bst\bt shell option
+ causes the shell to save the command with embedded newlines instead of
semicolons. See the description of the s\bsh\bho\bop\bpt\bt builtin below under S\bSH\bHE\bEL\bLL\bL
- B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS for information on setting and unsetting shell op-
+ B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS for information on setting and unsetting shell op-
tions.
H\bHI\bIS\bST\bTO\bOR\bRY\bY E\bEX\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN
- The shell supports a history expansion feature that is similar to the
- history expansion in c\bcs\bsh\bh. 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 c\bcs\bsh\bh. This section describes what syntax features
+ are available. This feature is enabled by default for interactive
shells, and can be disabled using the +\b+H\bH option to the s\bse\bet\bt builtin com-
- mand (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS below). Non-interactive shells do not
+ mand (see S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS 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, and is performed on each
- line individually without taking quoting on previous lines into ac-
- count. 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 _\be_\bv_\be_\bn_\bt, and the portions of that
- line that are acted upon are _\bw_\bo_\br_\bd_\bs. The line is broken into words in
- the same fashion as when reading input, so that several _\bm_\be_\bt_\ba_\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br-
- separated words surrounded by quotes are considered one word. The _\be_\bv_\be_\bn_\bt
- _\bd_\be_\bs_\bi_\bg_\bn_\ba_\bt_\bo_\br selects the event, the optional _\bw_\bo_\br_\bd _\bd_\be_\bs_\bi_\bg_\bn_\ba_\bt_\bo_\br selects
- words from the event, and various optional _\bm_\bo_\bd_\bi_\bf_\bi_\be_\br_\bs are available to
- manipulate the selected words.
-
- History expansions are introduced by the appearance of the history ex-
- pansion character, which is !\b! by default. History expansions may appear
- anywhere in the input, but do not nest.
-
- Only backslash (\\b\) and single quotes can quote the history expansion
- character, but the history expansion character is also treated as
+ History expansion is performed immediately after a complete line is
+ read, before the shell breaks it into words, and is performed on each
+ line individually without taking quoting on previous lines into ac-
+ count. 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 _\be_\bv_\be_\bn_\bt, and the portions of
+ that line that are acted upon are _\bw_\bo_\br_\bd_\bs. The line is broken into words
+ in the same fashion as when reading input, so that several _\bm_\be_\bt_\ba_\bc_\bh_\ba_\br_\ba_\bc_\b-
+ _\bt_\be_\br-separated words surrounded by quotes are considered one word. The
+ _\be_\bv_\be_\bn_\bt _\bd_\be_\bs_\bi_\bg_\bn_\ba_\bt_\bo_\br selects the event, the optional _\bw_\bo_\br_\bd _\bd_\be_\bs_\bi_\bg_\bn_\ba_\bt_\bo_\br se-
+ lects words from the event, and various optional _\bm_\bo_\bd_\bi_\bf_\bi_\be_\br_\bs are avail-
+ able to manipulate the selected words.
+
+ History expansions are introduced by the appearance of the history ex-
+ pansion character, which is !\b! by default. History expansions may ap-
+ pear anywhere in the input, but do not nest.
+
+ Only backslash (\\b\) and single quotes can quote the history expansion
+ character, but the history expansion character is also treated as
quoted if it immediately precedes the closing double quote in a double-
quoted string.
- Several characters inhibit history expansion if found immediately fol-
- lowing the history expansion character, even if it is unquoted: space,
- tab, newline, carriage return, =\b=, and the other shell metacharacters
+ Several characters inhibit history expansion if found immediately fol-
+ lowing the history expansion character, even if it is unquoted: space,
+ tab, newline, carriage return, =\b=, and the other shell metacharacters
defined above.
- Several shell options settable with the s\bsh\bho\bop\bpt\bt builtin may be used to
- tailor the behavior of history expansion. If the h\bhi\bis\bst\btv\bve\ber\bri\bif\bfy\by shell op-
- tion is enabled (see the description of the s\bsh\bho\bop\bpt\bt builtin below), and
- r\bre\bea\bad\bdl\bli\bin\bne\be is being used, history substitutions are not immediately
- passed to the shell parser. Instead, the expanded line is reloaded into
- the r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer for further modification. If r\bre\bea\bad\bdl\bli\bin\bne\be is
- being used, and the h\bhi\bis\bst\btr\bre\bee\bed\bdi\bit\bt shell option is enabled, a failed his-
- tory substitution will be reloaded into the r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer for
- correction. The -\b-p\bp option to the h\bhi\bis\bst\bto\bor\bry\by builtin command may be used to
- see what a history expansion will do before using it. The -\b-s\bs option to
- the h\bhi\bis\bst\bto\bor\bry\by builtin may be used to add commands to the end of the his-
- tory 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
+ Several shell options settable with the s\bsh\bho\bop\bpt\bt builtin may be used to
+ tailor the behavior of history expansion. If the h\bhi\bis\bst\btv\bve\ber\bri\bif\bfy\by shell op-
+ tion is enabled (see the description of the s\bsh\bho\bop\bpt\bt builtin below), and
+ r\bre\bea\bad\bdl\bli\bin\bne\be is being used, history substitutions are not immediately
+ passed to the shell parser. Instead, the expanded line is reloaded
+ into the r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer for further modification. If r\bre\bea\bad\bdl\bli\bin\bne\be
+ is being used, and the h\bhi\bis\bst\btr\bre\bee\bed\bdi\bit\bt shell option is enabled, a failed
+ history substitution will be reloaded into the r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer
+ for correction. The -\b-p\bp option to the h\bhi\bis\bst\bto\bor\bry\by builtin command may be
+ used to see what a history expansion will do before using it. The -\b-s\bs
+ option to the h\bhi\bis\bst\bto\bor\bry\by builtin may be used to add commands to the end of
+ the history list without actually executing them, so that they are
+ available for subsequent recall.
+
+ The shell allows control of the various characters used by the history
expansion mechanism (see the description of h\bhi\bis\bst\btc\bch\bha\bar\brs\bs above under S\bSh\bhe\bel\bll\bl
- V\bVa\bar\bri\bia\bab\bbl\ble\bes\bs). The shell uses the history comment character to mark his-
+ V\bVa\bar\bri\bia\bab\bbl\ble\bes\bs). The shell uses the history comment character to mark his-
tory timestamps when writing the history file.
E\bEv\bve\ben\bnt\bt D\bDe\bes\bsi\big\bgn\bna\bat\bto\bor\brs\bs
- An event designator is a reference to a command line entry in the his-
- tory list. The event designator consists of the portion of the word be-
- ginning with the history expansion character and ending with the word
- designator if present, or the end of the word. Unless the reference is
- absolute, events are relative to the current position in the history
+ An event designator is a reference to a command line entry in the his-
+ tory list. The event designator consists of the portion of the word
+ beginning with the history expansion character and ending with the word
+ designator if present, or the end of the word. Unless the reference is
+ absolute, events are relative to the current position in the history
list.
- !\b! Start a history substitution, except when followed by a b\bbl\bla\ban\bnk\bk,
- newline, carriage return, = or ( (when the e\bex\bxt\btg\bgl\blo\bob\bb shell option
+ !\b! Start a history substitution, except when followed by a b\bbl\bla\ban\bnk\bk,
+ newline, carriage return, = or ( (when the e\bex\bxt\btg\bgl\blo\bob\bb shell option
is enabled using the s\bsh\bho\bop\bpt\bt builtin).
!\b!_\bn Refer to command line _\bn.
!\b!-\b-_\bn Refer to the current command minus _\bn.
- !\b!!\b! Refer to the previous command. This is a synonym for `!-1'.
+ !\b!!\b! Refer to the previous command. This is a synonym for `!-1'.
!\b!_\bs_\bt_\br_\bi_\bn_\bg
- 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 _\bs_\bt_\br_\bi_\bn_\bg.
!\b!?\b?_\bs_\bt_\br_\bi_\bn_\bg[\b[?\b?]\b]
- Refer to the most recent command preceding the current position
- in the history list containing _\bs_\bt_\br_\bi_\bn_\bg. The trailing ?\b? may be
- omitted if _\bs_\bt_\br_\bi_\bn_\bg is followed immediately by a newline. If
- _\bs_\bt_\br_\bi_\bn_\bg is missing, the string from the most recent search is
+ Refer to the most recent command preceding the current position
+ in the history list containing _\bs_\bt_\br_\bi_\bn_\bg. The trailing ?\b? may be
+ omitted if _\bs_\bt_\br_\bi_\bn_\bg is followed immediately by a newline. If
+ _\bs_\bt_\br_\bi_\bn_\bg is missing, the string from the most recent search is
used; it is an error if there is no previous search string.
^\b^_\bs_\bt_\br_\bi_\bn_\bg_\b1^\b^_\bs_\bt_\br_\bi_\bn_\bg_\b2^\b^
- Quick substitution. Repeat the previous command, replacing
- _\bs_\bt_\br_\bi_\bn_\bg_\b1 with _\bs_\bt_\br_\bi_\bn_\bg_\b2. Equivalent to ``!!:s^_\bs_\bt_\br_\bi_\bn_\bg_\b1^_\bs_\bt_\br_\bi_\bn_\bg_\b2^''
+ Quick substitution. Repeat the previous command, replacing
+ _\bs_\bt_\br_\bi_\bn_\bg_\b1 with _\bs_\bt_\br_\bi_\bn_\bg_\b2. Equivalent to ``!!:s^_\bs_\bt_\br_\bi_\bn_\bg_\b1^_\bs_\bt_\br_\bi_\bn_\bg_\b2^''
(see M\bMo\bod\bdi\bif\bfi\bie\ber\brs\bs below).
!\b!#\b# The entire command line typed so far.
W\bWo\bor\brd\bd D\bDe\bes\bsi\big\bgn\bna\bat\bto\bor\brs\bs
- Word designators are used to select desired words from the event. A :\b:
- separates the event specification from the word designator. It may be
- omitted if the word designator begins with a ^\b^, $\b$, *\b*, -\b-, or %\b%. Words
- are numbered from the beginning of the line, with the first word being
- denoted by 0 (zero). Words are inserted into the current line separated
- by single spaces.
+ Word designators are used to select desired words from the event. A :\b:
+ separates the event specification from the word designator. It may be
+ omitted if the word designator begins with a ^\b^, $\b$, *\b*, -\b-, or %\b%. 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.
0\b0 (\b(z\bze\ber\bro\bo)\b)
- The zeroth word. For the shell, this is the command word.
+ The zeroth word. For the shell, this is the command word.
_\bn The _\bnth word.
- ^\b^ The first argument. That is, word 1.
- $\b$ The last word. This is usually the last argument, but will ex-
+ ^\b^ The first argument. That is, word 1.
+ $\b$ The last word. This is usually the last argument, but will ex-
pand to the zeroth word if there is only one word in the line.
- %\b% The first word matched by the most recent `?_\bs_\bt_\br_\bi_\bn_\bg?' search, if
- the search string begins with a character that is part of a
+ %\b% The first word matched by the most recent `?_\bs_\bt_\br_\bi_\bn_\bg?' search, if
+ the search string begins with a character that is part of a
word.
_\bx-\b-_\by A range of words; `-_\by' abbreviates `0-_\by'.
- *\b* All of the words but the zeroth. This is a synonym for `_\b1_\b-_\b$'. It
- is not an error to use *\b* if there is just one word in the event;
- the empty string is returned in that case.
+ *\b* All of the words but the zeroth. This is a synonym for `_\b1_\b-_\b$'.
+ It is not an error to use *\b* if there is just one word in the
+ event; the empty string is returned in that case.
x\bx*\b* Abbreviates _\bx_\b-_\b$.
- x\bx-\b- Abbreviates _\bx_\b-_\b$ like x\bx*\b*, but omits the last word. If x\bx is miss-
+ x\bx-\b- Abbreviates _\bx_\b-_\b$ like x\bx*\b*, but omits the last word. If x\bx is miss-
ing, it defaults to 0.
- 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.
M\bMo\bod\bdi\bif\bfi\bie\ber\brs\bs
- After the optional word designator, there may appear a sequence of one
- or more of the following modifiers, each preceded by a `:'. These mod-
+ After the optional word designator, there may appear a sequence of one
+ or more of the following modifiers, each preceded by a `:'. These mod-
ify, or edit, the word or words selected from the history event.
h\bh Remove a trailing filename component, leaving only the head.
e\be Remove all but the trailing suffix.
p\bp Print the new command but do not execute it.
q\bq Quote the substituted words, escaping further substitutions.
- x\bx Quote the substituted words as with q\bq, but break into words at
- b\bbl\bla\ban\bnk\bks\bs and newlines. The q\bq and x\bx modifiers are mutually exclu-
+ x\bx Quote the substituted words as with q\bq, but break into words at
+ b\bbl\bla\ban\bnk\bks\bs and newlines. The q\bq and x\bx modifiers are mutually exclu-
sive; the last one supplied is used.
s\bs/\b/_\bo_\bl_\bd/\b/_\bn_\be_\bw/\b/
- Substitute _\bn_\be_\bw for the first occurrence of _\bo_\bl_\bd in the event
+ Substitute _\bn_\be_\bw for the first occurrence of _\bo_\bl_\bd in the event
line. Any character may be used as the delimiter in place of /.
- The final delimiter is optional if it is the last character of
- the event line. The delimiter may be quoted in _\bo_\bl_\bd and _\bn_\be_\bw with
- a single backslash. If & appears in _\bn_\be_\bw, it is replaced by _\bo_\bl_\bd.
- A single backslash will quote the &. If _\bo_\bl_\bd is null, it is set
- to the last _\bo_\bl_\bd substituted, or, if no previous history substi-
- tutions took place, the last _\bs_\bt_\br_\bi_\bn_\bg in a !\b!?\b?_\bs_\bt_\br_\bi_\bn_\bg[\b[?\b?]\b] search. If
- _\bn_\be_\bw is null, each matching _\bo_\bl_\bd is deleted.
+ The final delimiter is optional if it is the last character of
+ the event line. The delimiter may be quoted in _\bo_\bl_\bd and _\bn_\be_\bw with
+ a single backslash. If & appears in _\bn_\be_\bw, it is replaced by _\bo_\bl_\bd.
+ A single backslash will quote the &. If _\bo_\bl_\bd is null, it is set
+ to the last _\bo_\bl_\bd substituted, or, if no previous history substi-
+ tutions took place, the last _\bs_\bt_\br_\bi_\bn_\bg in a !\b!?\b?_\bs_\bt_\br_\bi_\bn_\bg[\b[?\b?]\b] search.
+ If _\bn_\be_\bw is null, each matching _\bo_\bl_\bd is deleted.
&\b& Repeat the previous substitution.
- g\bg Cause changes to be applied over the entire event line. This is
- used in conjunction with `:\b:s\bs' (e.g., `:\b:g\bgs\bs/\b/_\bo_\bl_\bd/\b/_\bn_\be_\bw/\b/') or `:\b:&\b&'. If
- used with `:\b:s\bs', 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 a\ba may be used as a synonym for g\bg.
+ g\bg Cause changes to be applied over the entire event line. This is
+ used in conjunction with `:\b:s\bs' (e.g., `:\b:g\bgs\bs/\b/_\bo_\bl_\bd/\b/_\bn_\be_\bw/\b/') or `:\b:&\b&'.
+ If used with `:\b:s\bs', 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 a\ba may be used as a synonym for g\bg.
G\bG Apply the following `s\bs' or `&\b&' modifier once to each word in the
event line.
Unless otherwise noted, each builtin command documented in this section
as accepting options preceded by -\b- accepts -\b--\b- to signify the end of the
options. The :\b:, t\btr\bru\bue\be, f\bfa\bal\bls\bse\be, and t\bte\bes\bst\bt/[\b[ builtins do not accept options
- and do not treat -\b--\b- specially. The e\bex\bxi\bit\bt, l\blo\bog\bgo\bou\but\bt, r\bre\bet\btu\bur\brn\bn, b\bbr\bre\bea\bak\bk, c\bco\bon\bn-\b-
- t\bti\bin\bnu\bue\be, l\ble\bet\bt, and s\bsh\bhi\bif\bft\bt builtins accept and process arguments beginning
- with -\b- without requiring -\b--\b-. Other builtins that accept arguments but
- are not specified as accepting options interpret arguments beginning
- with -\b- as invalid options and require -\b--\b- to prevent this interpreta-
+ and do not treat -\b--\b- specially. The e\bex\bxi\bit\bt, l\blo\bog\bgo\bou\but\bt, r\bre\bet\btu\bur\brn\bn, b\bbr\bre\bea\bak\bk, c\bco\bon\bn-\b-
+ t\bti\bin\bnu\bue\be, l\ble\bet\bt, and s\bsh\bhi\bif\bft\bt builtins accept and process arguments beginning
+ with -\b- without requiring -\b--\b-. Other builtins that accept arguments but
+ are not specified as accepting options interpret arguments beginning
+ with -\b- as invalid options and require -\b--\b- to prevent this interpreta-
tion.
:\b: [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
- No effect; the command does nothing beyond expanding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs
- and performing any specified redirections. The return status is
+ No effect; the command does nothing beyond expanding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs
+ and performing any specified redirections. The return status is
zero.
.\b. _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
s\bso\bou\bur\brc\bce\be _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
Read and execute commands from _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be in the current shell en-
- vironment and return the exit status of the last command exe-
- cuted from _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not contain a slash, file-
- names in P\bPA\bAT\bTH\bH are used to find the directory containing _\bf_\bi_\bl_\be_\b-
- _\bn_\ba_\bm_\be, but _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not need to be executable. The file
- searched for in P\bPA\bAT\bTH\bH need not be executable. When b\bba\bas\bsh\bh is not in
- _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, it searches the current directory if no file is
- found in P\bPA\bAT\bTH\bH. If the s\bso\bou\bur\brc\bce\bep\bpa\bat\bth\bh option to the s\bsh\bho\bop\bpt\bt builtin
- command is turned off, the P\bPA\bAT\bTH\bH is not searched. If any _\ba_\br_\bg_\bu_\b-
- _\bm_\be_\bn_\bt_\bs are supplied, they become the positional parameters when
- _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is executed. Otherwise the positional parameters are
- unchanged. If the -\b-T\bT option is enabled, .\b. inherits any trap on
+ vironment and return the exit status of the last command exe-
+ cuted from _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not contain a slash,
+ filenames in P\bPA\bAT\bTH\bH are used to find the directory containing
+ _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be, but _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not need to be executable. The file
+ searched for in P\bPA\bAT\bTH\bH need not be executable. When b\bba\bas\bsh\bh is not
+ in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, it searches the current directory if no file is
+ found in P\bPA\bAT\bTH\bH. If the s\bso\bou\bur\brc\bce\bep\bpa\bat\bth\bh option to the s\bsh\bho\bop\bpt\bt builtin
+ command is turned off, the P\bPA\bAT\bTH\bH is not searched. If any _\ba_\br_\bg_\bu_\b-
+ _\bm_\be_\bn_\bt_\bs are supplied, they become the positional parameters when
+ _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is executed. Otherwise the positional parameters are
+ unchanged. If the -\b-T\bT option is enabled, .\b. inherits any trap on
D\bDE\bEB\bBU\bUG\bG; if it is not, any D\bDE\bEB\bBU\bUG\bG trap string is saved and restored
- around the call to .\b., and .\b. unsets the D\bDE\bEB\bBU\bUG\bG trap while it exe-
+ around the call to .\b., and .\b. unsets the D\bDE\bEB\bBU\bUG\bG trap while it exe-
cutes. If -\b-T\bT is not set, and the sourced file changes the D\bDE\bEB\bBU\bUG\bG
- trap, the new value is retained when .\b. completes. The return
- status is the status of the last command exited within the
+ trap, the new value is retained when .\b. completes. The return
+ status is the status of the last command exited within the
script (0 if no commands are executed), and false if _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is
not found or cannot be read.
a\bal\bli\bia\bas\bs [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ...]
A\bAl\bli\bia\bas\bs with no arguments or with the -\b-p\bp option prints the list of
- aliases in the form a\bal\bli\bia\bas\bs _\bn_\ba_\bm_\be=_\bv_\ba_\bl_\bu_\be on standard output. When
- arguments are supplied, an alias is defined for each _\bn_\ba_\bm_\be whose
- _\bv_\ba_\bl_\bu_\be is given. A trailing space in _\bv_\ba_\bl_\bu_\be causes the next word
+ aliases in the form a\bal\bli\bia\bas\bs _\bn_\ba_\bm_\be=_\bv_\ba_\bl_\bu_\be on standard output. When
+ arguments are supplied, an alias is defined for each _\bn_\ba_\bm_\be whose
+ _\bv_\ba_\bl_\bu_\be is given. A trailing space in _\bv_\ba_\bl_\bu_\be causes the next word
to be checked for alias substitution when the alias is expanded.
- For each _\bn_\ba_\bm_\be in the argument list for which no _\bv_\ba_\bl_\bu_\be is sup-
- plied, the name and value of the alias is printed. A\bAl\bli\bia\bas\bs returns
- true unless a _\bn_\ba_\bm_\be is given for which no alias has been defined.
+ For each _\bn_\ba_\bm_\be in the argument list for which no _\bv_\ba_\bl_\bu_\be is sup-
+ plied, the name and value of the alias is printed. A\bAl\bli\bia\bas\bs re-
+ turns true unless a _\bn_\ba_\bm_\be is given for which no alias has been
+ defined.
b\bbg\bg [_\bj_\bo_\bb_\bs_\bp_\be_\bc ...]
Resume each suspended job _\bj_\bo_\bb_\bs_\bp_\be_\bc in the background, as if it
- had been started with &\b&. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, the shell's
- notion of the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. b\bbg\bg _\bj_\bo_\bb_\bs_\bp_\be_\bc returns 0 unless
+ had been started with &\b&. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, the shell's
+ notion of the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. b\bbg\bg _\bj_\bo_\bb_\bs_\bp_\be_\bc returns 0 unless
run when job control is disabled or, when run with job control
enabled, any specified _\bj_\bo_\bb_\bs_\bp_\be_\bc was not found or was started
without job control.
variable. Each non-option argument is a command as it would ap-
pear in a r\bre\bea\bad\bdl\bli\bin\bne\be initialization file such as _\b._\bi_\bn_\bp_\bu_\bt_\br_\bc, 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,
+ e.g., '"\C-x\C-r": re-read-init-file'. Options, if supplied,
have the following meanings:
-\b-m\bm _\bk_\be_\by_\bm_\ba_\bp
Use _\bk_\be_\by_\bm_\ba_\bp as the keymap to be affected by the subsequent
- bindings. Acceptable _\bk_\be_\by_\bm_\ba_\bp names are _\be_\bm_\ba_\bc_\bs_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\b-
+ bindings. Acceptable _\bk_\be_\by_\bm_\ba_\bp names are _\be_\bm_\ba_\bc_\bs_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\b-
_\bd_\ba_\br_\bd_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bm_\be_\bt_\ba_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bc_\bt_\bl_\bx_\b, _\bv_\bi_\b, _\bv_\bi_\b-_\bm_\bo_\bv_\be_\b, _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd,
- and _\bv_\bi_\b-_\bi_\bn_\bs_\be_\br_\bt. _\bv_\bi is equivalent to _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd (_\bv_\bi_\b-_\bm_\bo_\bv_\be is
- also a synonym); _\be_\bm_\ba_\bc_\bs is equivalent to _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd.
+ and _\bv_\bi_\b-_\bi_\bn_\bs_\be_\br_\bt. _\bv_\bi is equivalent to _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd (_\bv_\bi_\b-_\bm_\bo_\bv_\be
+ is also a synonym); _\be_\bm_\ba_\bc_\bs is equivalent to _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\b-
+ _\bd_\ba_\br_\bd.
-\b-l\bl List the names of all r\bre\bea\bad\bdl\bli\bin\bne\be functions.
- -\b-p\bp Display r\bre\bea\bad\bdl\bli\bin\bne\be function names and bindings in such a
+ -\b-p\bp Display r\bre\bea\bad\bdl\bli\bin\bne\be function names and bindings in such a
way that they can be re-read.
-\b-P\bP List current r\bre\bea\bad\bdl\bli\bin\bne\be function names and bindings.
- -\b-s\bs Display r\bre\bea\bad\bdl\bli\bin\bne\be key sequences bound to macros and the
- strings they output in such a way that they can be re-
+ -\b-s\bs Display r\bre\bea\bad\bdl\bli\bin\bne\be key sequences bound to macros and the
+ strings they output in such a way that they can be re-
read.
- -\b-S\bS Display r\bre\bea\bad\bdl\bli\bin\bne\be key sequences bound to macros and the
+ -\b-S\bS Display r\bre\bea\bad\bdl\bli\bin\bne\be key sequences bound to macros and the
strings they output.
- -\b-v\bv Display r\bre\bea\bad\bdl\bli\bin\bne\be variable names and values in such a way
+ -\b-v\bv Display r\bre\bea\bad\bdl\bli\bin\bne\be variable names and values in such a way
that they can be re-read.
-\b-V\bV List current r\bre\bea\bad\bdl\bli\bin\bne\be variable names and values.
-\b-f\bf _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be
-\b-x\bx _\bk_\be_\by_\bs_\be_\bq[\b[:\b: ]\b]_\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd
Cause _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd to be executed whenever _\bk_\be_\by_\bs_\be_\bq is en-
tered. The separator between _\bk_\be_\by_\bs_\be_\bq and _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd is
- either whitespace or a colon optionally followed by
- whitespace. If the separator is whitespace, _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd
- must be enclosed in double quotes and r\bre\bea\bad\bdl\bli\bin\bne\be expands
- any of its special backslash-escapes in _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd be-
- fore saving it. If the separator is a colon, any enclos-
- ing double quotes are optional, and r\bre\bea\bad\bdl\bli\bin\bne\be does not ex-
- pand the command string before saving it. Since the en-
- tire key binding expression must be a single argument, it
- should be enclosed in quotes. When _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd is exe-
- cuted, the shell sets the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE variable to the
- contents of the r\bre\bea\bad\bdl\bli\bin\bne\be line buffer and the R\bRE\bEA\bAD\bD-\b-
- L\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT and R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK variables to the current lo-
- cation of the insertion point and the saved insertion
- point (the mark), respectively. The shell assigns any nu-
- meric argument the user supplied to the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_A\bAR\bRG\bGU\bUM\bME\bEN\bNT\bT
- variable. If there was no argument, that variable is not
- set. If the executed command changes the value of any of
- R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE, R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT, or R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK, those
- new values will be reflected in the editing state.
- -\b-X\bX List all key sequences bound to shell commands and the
+ either whitespace or a colon optionally followed by
+ whitespace. If the separator is whitespace, _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\b-
+ _\bm_\ba_\bn_\bd must be enclosed in double quotes and r\bre\bea\bad\bdl\bli\bin\bne\be ex-
+ pands any of its special backslash-escapes in _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\b-
+ _\bm_\ba_\bn_\bd before saving it. If the separator is a colon, any
+ enclosing double quotes are optional, and r\bre\bea\bad\bdl\bli\bin\bne\be does
+ not expand the command string before saving it. Since
+ the entire key binding expression must be a single argu-
+ ment, it should be enclosed in quotes. When _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\b-
+ _\bm_\ba_\bn_\bd is executed, the shell sets the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE vari-
+ able to the contents of the r\bre\bea\bad\bdl\bli\bin\bne\be line buffer and the
+ R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT and R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK variables to the current
+ location of the insertion point and the saved insertion
+ point (the mark), respectively. The shell assigns any
+ numeric argument the user supplied to the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_A\bAR\bRG\bGU\bU-\b-
+ M\bME\bEN\bNT\bT variable. If there was no argument, that variable
+ is not set. If the executed command changes the value of
+ any of R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE, R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT, or R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK,
+ those new values will be reflected in the editing state.
+ -\b-X\bX List all key sequences bound to shell commands and the
associated commands in a format that can be reused as in-
put.
- 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.
b\bbr\bre\bea\bak\bk [_\bn]
- Exit from within a f\bfo\bor\br, w\bwh\bhi\bil\ble\be, u\bun\bnt\bti\bil\bl, or s\bse\bel\ble\bec\bct\bt loop. If _\bn is
- specified, break _\bn levels. _\bn must be >= 1. If _\bn is greater than
- the number of enclosing loops, all enclosing loops are exited.
- The return value is 0 unless _\bn is not greater than or equal to
- 1.
+ Exit from within a f\bfo\bor\br, w\bwh\bhi\bil\ble\be, u\bun\bnt\bti\bil\bl, or s\bse\bel\ble\bec\bct\bt loop. If _\bn is
+ specified, break _\bn levels. _\bn must be >= 1. If _\bn is greater
+ than the number of enclosing loops, all enclosing loops are ex-
+ ited. The return value is 0 unless _\bn is not greater than or
+ equal to 1.
b\bbu\bui\bil\blt\bti\bin\bn _\bs_\bh_\be_\bl_\bl_\b-_\bb_\bu_\bi_\bl_\bt_\bi_\bn [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
- Execute the specified shell builtin, passing it _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs, and
- return its exit status. This is useful when defining a function
- whose name is the same as a shell builtin, retaining the func-
- tionality of the builtin within the function. The c\bcd\bd builtin is
- commonly redefined this way. The return status is false if
+ Execute the specified shell builtin, passing it _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs, and
+ return its exit status. This is useful when defining a function
+ whose name is the same as a shell builtin, retaining the func-
+ tionality of the builtin within the function. The c\bcd\bd builtin is
+ commonly redefined this way. The return status is false if
_\bs_\bh_\be_\bl_\bl_\b-_\bb_\bu_\bi_\bl_\bt_\bi_\bn is not a shell builtin command.
c\bca\bal\bll\ble\ber\br [_\be_\bx_\bp_\br]
Returns the context of any active subroutine call (a shell func-
- tion or a script executed with the .\b. or s\bso\bou\bur\brc\bce\be builtins). With-
+ tion or a script executed with the .\b. or s\bso\bou\bur\brc\bce\be builtins). With-
out _\be_\bx_\bp_\br, c\bca\bal\bll\ble\ber\br 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 _\be_\bx_\bp_\br, c\bca\bal\bll\ble\ber\br 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 _\be_\bx_\bp_\br 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 _\be_\bx_\bp_\br does not correspond to a valid position in
the call stack.
c\bcd\bd [-\b-L\bL|[-\b-P\bP [-\b-e\be]]] [-@] [_\bd_\bi_\br]
- Change the current directory to _\bd_\bi_\br. if _\bd_\bi_\br is not supplied, the
- value of the H\bHO\bOM\bME\bE shell variable is the default. The variable
- C\bCD\bDP\bPA\bAT\bTH\bH defines the search path for the directory containing _\bd_\bi_\br:
- each directory name in C\bCD\bDP\bPA\bAT\bTH\bH is searched for _\bd_\bi_\br. Alternative
- directory names in C\bCD\bDP\bPA\bAT\bTH\bH are separated by a colon (:). A null
- directory name in C\bCD\bDP\bPA\bAT\bTH\bH is the same as the current directory,
- i.e., ``.\b.''. If _\bd_\bi_\br begins with a slash (/), then C\bCD\bDP\bPA\bAT\bTH\bH is not
- used. The -\b-P\bP option causes c\bcd\bd to use the physical directory
- structure by resolving symbolic links while traversing _\bd_\bi_\br and
- before processing instances of _\b._\b. in _\bd_\bi_\br (see also the -\b-P\bP option
- to the s\bse\bet\bt builtin command); the -\b-L\bL option forces symbolic links
- to be followed by resolving the link after processing instances
- of _\b._\b. in _\bd_\bi_\br. If _\b._\b. appears in _\bd_\bi_\br, it is processed by removing
- the immediately previous pathname component from _\bd_\bi_\br, back to a
- slash or the beginning of _\bd_\bi_\br. If the -\b-e\be option is supplied with
- -\b-P\bP, and the current working directory cannot be successfully de-
- termined after a successful directory change, c\bcd\bd will return an
- unsuccessful status. On systems that support it, the -\b-@\b@ option
- presents the extended attributes associated with a file as a di-
- rectory. An argument of -\b- is converted to $\b$O\bOL\bLD\bDP\bPW\bWD\bD before the di-
- rectory change is attempted. If a non-empty directory name from
- C\bCD\bDP\bPA\bAT\bTH\bH is used, or if -\b- is the first argument, and the directory
- change is successful, the absolute pathname of the new working
- directory is written to the standard output. If the directory
- change is successful, c\bcd\bd sets the value of the P\bPW\bWD\bD environment
- variable to the new directory name, and sets the O\bOL\bLD\bDP\bPW\bWD\bD environ-
- ment variable to the value of the current working directory be-
- fore the change. The return value is true if the directory was
- successfully changed; false otherwise.
+ Change the current directory to _\bd_\bi_\br. if _\bd_\bi_\br is not supplied,
+ the value of the H\bHO\bOM\bME\bE shell variable is the default. The vari-
+ able C\bCD\bDP\bPA\bAT\bTH\bH defines the search path for the directory containing
+ _\bd_\bi_\br: each directory name in C\bCD\bDP\bPA\bAT\bTH\bH is searched for _\bd_\bi_\br. Alter-
+ native directory names in C\bCD\bDP\bPA\bAT\bTH\bH are separated by a colon (:).
+ A null directory name in C\bCD\bDP\bPA\bAT\bTH\bH is the same as the current di-
+ rectory, i.e., ``.\b.''. If _\bd_\bi_\br begins with a slash (/), then C\bCD\bD-\b-
+ P\bPA\bAT\bTH\bH is not used. The -\b-P\bP option causes c\bcd\bd to use the physical
+ directory structure by resolving symbolic links while traversing
+ _\bd_\bi_\br and before processing instances of _\b._\b. in _\bd_\bi_\br (see also the
+ -\b-P\bP option to the s\bse\bet\bt builtin command); the -\b-L\bL option forces sym-
+ bolic links to be followed by resolving the link after process-
+ ing instances of _\b._\b. in _\bd_\bi_\br. If _\b._\b. appears in _\bd_\bi_\br, it is pro-
+ cessed by removing the immediately previous pathname component
+ from _\bd_\bi_\br, back to a slash or the beginning of _\bd_\bi_\br. If the -\b-e\be
+ option is supplied with -\b-P\bP, and the current working directory
+ cannot be successfully determined after a successful directory
+ change, c\bcd\bd will return an unsuccessful status. On systems that
+ support it, the -\b-@\b@ option presents the extended attributes asso-
+ ciated with a file as a directory. An argument of -\b- is con-
+ verted to $\b$O\bOL\bLD\bDP\bPW\bWD\bD before the directory change is attempted. If
+ a non-empty directory name from C\bCD\bDP\bPA\bAT\bTH\bH is used, or if -\b- is the
+ first argument, and the directory change is successful, the ab-
+ solute pathname of the new working directory is written to the
+ standard output. If the directory change is successful, c\bcd\bd sets
+ the value of the P\bPW\bWD\bD environment variable to the new directory
+ name, and sets the O\bOL\bLD\bDP\bPW\bWD\bD environment variable to the value of
+ the current working directory before the change. The return
+ value is true if the directory was successfully changed; false
+ otherwise.
c\bco\bom\bmm\bma\ban\bnd\bd [-\b-p\bpV\bVv\bv] _\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\ba_\br_\bg ...]
Run _\bc_\bo_\bm_\bm_\ba_\bn_\bd with _\ba_\br_\bg_\bs suppressing the normal shell function
lookup. Only builtin commands or commands found in the P\bPA\bAT\bTH\bH are
- executed. If the -\b-p\bp option is given, the search for _\bc_\bo_\bm_\bm_\ba_\bn_\bd is
+ executed. If the -\b-p\bp option is given, the search for _\bc_\bo_\bm_\bm_\ba_\bn_\bd is
performed using a default value for P\bPA\bAT\bTH\bH that is guaranteed to
- find all of the standard utilities. If either the -\b-V\bV or -\b-v\bv op-
- tion is supplied, a description of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is printed. The -\b-v\bv
+ find all of the standard utilities. If either the -\b-V\bV or -\b-v\bv op-
+ tion is supplied, a description of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is printed. The -\b-v\bv
option causes a single word indicating the command or filename
used to invoke _\bc_\bo_\bm_\bm_\ba_\bn_\bd to be displayed; the -\b-V\bV option produces a
- more verbose description. If the -\b-V\bV or -\b-v\bv option is supplied,
- the exit status is 0 if _\bc_\bo_\bm_\bm_\ba_\bn_\bd was found, and 1 if not. If nei-
- ther option is supplied and an error occurred or _\bc_\bo_\bm_\bm_\ba_\bn_\bd cannot
- be found, the exit status is 127. Otherwise, the exit status of
- the c\bco\bom\bmm\bma\ban\bnd\bd builtin is the exit status of _\bc_\bo_\bm_\bm_\ba_\bn_\bd.
+ more verbose description. If the -\b-V\bV or -\b-v\bv option is supplied,
+ the exit status is 0 if _\bc_\bo_\bm_\bm_\ba_\bn_\bd was found, and 1 if not. If
+ neither option is supplied and an error occurred or _\bc_\bo_\bm_\bm_\ba_\bn_\bd can-
+ not be found, the exit status is 127. Otherwise, the exit sta-
+ tus of the c\bco\bom\bmm\bma\ban\bnd\bd builtin is the exit status of _\bc_\bo_\bm_\bm_\ba_\bn_\bd.
c\bco\bom\bmp\bpg\bge\ben\bn [-\b-V\bV _\bv_\ba_\br_\bn_\ba_\bm_\be] [_\bo_\bp_\bt_\bi_\bo_\bn] [_\bw_\bo_\br_\bd]
Generate possible completion matches for _\bw_\bo_\br_\bd according to the
_\bo_\bp_\bt_\bi_\bo_\bns, which may be any option accepted by the c\bco\bom\bmp\bpl\ble\bet\bte\be
builtin with the exceptions of -\b-p\bp, -\b-r\br, -\b-D\bD, -\b-E\bE, and -\b-I\bI, and write
- the matches to the standard output. If the -\b-V\bV option is sup-
+ the matches to the standard output. If the -\b-V\bV option is sup-
plied, c\bco\bom\bmp\bpg\bge\ben\bn stores the generated completions into the indexed
array variable _\bv_\ba_\br_\bn_\ba_\bm_\be instead of writing them to the standard
- output. When using the -\b-F\bF or -\b-C\bC options, the various shell vari-
- ables set by the programmable completion facilities, while
+ output. When using the -\b-F\bF or -\b-C\bC 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 program-
mable completion code had generated them directly from a comple-
- tion specification with the same flags. If _\bw_\bo_\br_\bd is specified,
+ tion specification with the same flags. If _\bw_\bo_\br_\bd is specified,
only those completions matching _\bw_\bo_\br_\bd will be displayed.
The return value is true unless an invalid option is supplied,
Specify how arguments to each _\bn_\ba_\bm_\be should be completed. If the
-\b-p\bp 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 -\b-r\br option removes a completion speci-
- fication for each _\bn_\ba_\bm_\be, or, if no _\bn_\ba_\bm_\bes are supplied, all com-
- pletion specifications. The -\b-D\bD option indicates that other sup-
+ to be reused as input. The -\b-r\br option removes a completion spec-
+ ification for each _\bn_\ba_\bm_\be, or, if no _\bn_\ba_\bm_\bes are supplied, all com-
+ pletion specifications. The -\b-D\bD option indicates that other sup-
plied options and actions should apply to the ``default'' com-
mand completion; that is, completion attempted on a command for
- which no completion has previously been defined. The -\b-E\bE option
+ which no completion has previously been defined. The -\b-E\bE option
indicates that other supplied options and actions should apply
to ``empty'' command completion; that is, completion attempted
- on a blank line. The -\b-I\bI option indicates that other supplied op-
- tions and actions should apply to completion on the initial non-
- assignment word on the line, or after a command delimiter such
- as ;\b; or |\b|, which is usually command name completion. If multiple
- options are supplied, the -\b-D\bD option takes precedence over -\b-E\bE,
- and both take precedence over -\b-I\bI. If any of -\b-D\bD, -\b-E\bE, or -\b-I\bI are
- supplied, any other _\bn_\ba_\bm_\be arguments are ignored; these comple-
- tions only apply to the case specified by the option.
+ on a blank line. The -\b-I\bI option indicates that other supplied
+ options and actions should apply to completion on the initial
+ non-assignment word on the line, or after a command delimiter
+ such as ;\b; or |\b|, which is usually command name completion. If
+ multiple options are supplied, the -\b-D\bD option takes precedence
+ over -\b-E\bE, and both take precedence over -\b-I\bI. If any of -\b-D\bD, -\b-E\bE, or
+ -\b-I\bI are supplied, any other _\bn_\ba_\bm_\be arguments are ignored; these
+ completions only apply to the case specified by the option.
The process of applying these completion specifications when
word completion is attempted is described above under P\bPr\bro\bog\bgr\bra\bam\bm-\b-
m\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn.
- Other options, if specified, have the following meanings. The
+ Other options, if specified, have the following meanings. The
arguments to the -\b-G\bG, -\b-W\bW, and -\b-X\bX options (and, if necessary, the
-\b-P\bP and -\b-S\bS options) should be quoted to protect them from expan-
sion before the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin is invoked.
-\b-o\bo _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn
The _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn controls several aspects of the comp-
spec's behavior beyond the simple generation of comple-
- tions. _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn may be one of:
+ tions. _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn may be one of:
b\bba\bas\bsh\bhd\bde\bef\bfa\bau\bul\blt\bt
Perform the rest of the default b\bba\bas\bsh\bh completions
if the compspec generates no matches.
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
+ ing trailing spaces). Intended to be used with
shell functions.
f\bfu\bul\bll\blq\bqu\buo\bot\bte\be
Tell readline to quote all the completed words
-\b-A\bA _\ba_\bc_\bt_\bi_\bo_\bn
The _\ba_\bc_\bt_\bi_\bo_\bn may be one of the following to generate a
list of possible completions:
- a\bal\bli\bia\bas\bs Alias names. May also be specified as -\b-a\ba.
+ a\bal\bli\bia\bas\bs Alias names. May also be specified as -\b-a\ba.
a\bar\brr\bra\bay\byv\bva\bar\br
Array variable names.
b\bbi\bin\bnd\bdi\bin\bng\bg R\bRe\bea\bad\bdl\bli\bin\bne\be key binding names.
- b\bbu\bui\bil\blt\bti\bin\bn Names of shell builtin commands. May also be
+ b\bbu\bui\bil\blt\bti\bin\bn Names of shell builtin commands. May also be
specified as -\b-b\bb.
- c\bco\bom\bmm\bma\ban\bnd\bd Command names. May also be specified as -\b-c\bc.
+ c\bco\bom\bmm\bma\ban\bnd\bd Command names. May also be specified as -\b-c\bc.
d\bdi\bir\bre\bec\bct\bto\bor\bry\by
- Directory names. May also be specified as -\b-d\bd.
+ Directory names. May also be specified as -\b-d\bd.
d\bdi\bis\bsa\bab\bbl\ble\bed\bd
Names of disabled shell builtins.
e\ben\bna\bab\bbl\ble\bed\bd Names of enabled shell builtins.
- e\bex\bxp\bpo\bor\brt\bt Names of exported shell variables. May also be
+ e\bex\bxp\bpo\bor\brt\bt Names of exported shell variables. May also be
specified as -\b-e\be.
- f\bfi\bil\ble\be File names. May also be specified as -\b-f\bf.
+ f\bfi\bil\ble\be File names. May also be specified as -\b-f\bf.
f\bfu\bun\bnc\bct\bti\bio\bon\bn
Names of shell functions.
- g\bgr\bro\bou\bup\bp Group names. May also be specified as -\b-g\bg.
+ g\bgr\bro\bou\bup\bp Group names. May also be specified as -\b-g\bg.
h\bhe\bel\blp\bpt\bto\bop\bpi\bic\bc
Help topics as accepted by the h\bhe\bel\blp\bp builtin.
h\bho\bos\bst\btn\bna\bam\bme\be
Hostnames, as taken from the file specified by
the H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE shell variable.
- j\bjo\bob\bb Job names, if job control is active. May also be
- specified as -\b-j\bj.
- k\bke\bey\byw\bwo\bor\brd\bd Shell reserved words. May also be specified as
+ j\bjo\bob\bb Job names, if job control is active. May also
+ be specified as -\b-j\bj.
+ k\bke\bey\byw\bwo\bor\brd\bd Shell reserved words. May also be specified as
-\b-k\bk.
r\bru\bun\bnn\bni\bin\bng\bg Names of running jobs, if job control is active.
- s\bse\ber\brv\bvi\bic\bce\be Service names. May also be specified as -\b-s\bs.
+ s\bse\ber\brv\bvi\bic\bce\be Service names. May also be specified as -\b-s\bs.
s\bse\bet\bto\bop\bpt\bt Valid arguments for the -\b-o\bo option to the s\bse\bet\bt
builtin.
s\bsh\bho\bop\bpt\bt Shell option names as accepted by the s\bsh\bho\bop\bpt\bt
builtin.
s\bsi\big\bgn\bna\bal\bl Signal names.
s\bst\bto\bop\bpp\bpe\bed\bd Names of stopped jobs, if job control is active.
- u\bus\bse\ber\br User names. May also be specified as -\b-u\bu.
+ u\bus\bse\ber\br User names. May also be specified as -\b-u\bu.
v\bva\bar\bri\bia\bab\bbl\ble\be
- Names of all shell variables. May also be speci-
- fied as -\b-v\bv.
+ Names of all shell variables. May also be spec-
+ ified as -\b-v\bv.
-\b-C\bC _\bc_\bo_\bm_\bm_\ba_\bn_\bd
_\bc_\bo_\bm_\bm_\ba_\bn_\bd is executed in a subshell environment, and its
- output is used as the possible completions. Arguments
+ output is used as the possible completions. Arguments
are passed as with the -\b-F\bF option.
-\b-F\bF _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn
The shell function _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn is executed in the current
- shell environment. When the function is executed, the
+ shell environment. When the function is executed, the
first argument ($\b$1\b1) is the name of the command whose ar-
guments are being completed, the second argument ($\b$2\b2) is
the word being completed, and the third argument ($\b$3\b3) is
the word preceding the word being completed on the cur-
- rent command line. When it finishes, the possible com-
+ rent command line. When it finishes, the possible com-
pletions are retrieved from the value of the C\bCO\bOM\bMP\bPR\bRE\bEP\bPL\bLY\bY
array variable.
-\b-G\bG _\bg_\bl_\bo_\bb_\bp_\ba_\bt
-\b-W\bW _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt
The _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt is split using the characters in the I\bIF\bFS\bS
special variable as delimiters, and each resultant word
- is expanded. Shell quoting is honored within _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt,
+ is expanded. Shell quoting is honored within _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt,
in order to provide a mechanism for the words to contain
shell metacharacters or characters in the value of I\bIF\bFS\bS.
The possible completions are the members of the resul-
c\bco\bom\bmp\bpo\bop\bpt\bt [-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn] [-\b-D\bDE\bEI\bI] [+\b+o\bo _\bo_\bp_\bt_\bi_\bo_\bn] [_\bn_\ba_\bm_\be]
Modify completion options for each _\bn_\ba_\bm_\be according to the _\bo_\bp_\b-
_\bt_\bi_\bo_\bns, or for the currently-executing completion if no _\bn_\ba_\bm_\bes are
- supplied. If no _\bo_\bp_\bt_\bi_\bo_\bns are given, display the completion op-
- tions for each _\bn_\ba_\bm_\be or the current completion. The possible val-
- ues of _\bo_\bp_\bt_\bi_\bo_\bn are those valid for the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin described
- above. The -\b-D\bD option indicates that other supplied options
- should apply to the ``default'' command completion; that is,
- completion attempted on a command for which no completion has
- previously been defined. The -\b-E\bE option indicates that other sup-
- plied options should apply to ``empty'' command completion; that
- is, completion attempted on a blank line. The -\b-I\bI option indi-
- cates that other supplied options should apply to completion on
- the initial non-assignment word on the line, or after a command
- delimiter such as ;\b; or |\b|, which is usually command name comple-
- tion.
+ supplied. If no _\bo_\bp_\bt_\bi_\bo_\bns are given, display the completion op-
+ tions for each _\bn_\ba_\bm_\be or the current completion. The possible
+ values of _\bo_\bp_\bt_\bi_\bo_\bn are those valid for the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin de-
+ scribed above. The -\b-D\bD option indicates that other supplied op-
+ tions should apply to the ``default'' command completion; that
+ is, completion attempted on a command for which no completion
+ has previously been defined. The -\b-E\bE option indicates that other
+ supplied options should apply to ``empty'' command completion;
+ that is, completion attempted on a blank line. The -\b-I\bI option
+ indicates that other supplied options should apply to completion
+ on the initial non-assignment word on the line, or after a com-
+ mand delimiter such as ;\b; or |\b|, which is usually command name
+ completion.
The return value is true unless an invalid option is supplied,
an attempt is made to modify the options for a _\bn_\ba_\bm_\be for which no
c\bco\bon\bnt\bti\bin\bnu\bue\be [_\bn]
Resume the next iteration of the enclosing f\bfo\bor\br, w\bwh\bhi\bil\ble\be, u\bun\bnt\bti\bil\bl, or
- s\bse\bel\ble\bec\bct\bt loop. If _\bn is specified, resume at the _\bnth enclosing
- loop. _\bn must be >= 1. If _\bn is greater than the number of enclos-
- ing loops, the last enclosing loop (the ``top-level'' loop) is
- resumed. The return value is 0 unless _\bn is not greater than or
- equal to 1.
+ s\bse\bel\ble\bec\bct\bt loop. If _\bn is specified, resume at the _\bnth enclosing
+ loop. _\bn must be >= 1. If _\bn is greater than the number of en-
+ closing loops, the last enclosing loop (the ``top-level'' loop)
+ is resumed. The return value is 0 unless _\bn is not greater than
+ or equal to 1.
d\bde\bec\bcl\bla\bar\bre\be [-\b-a\baA\bAf\bfF\bFg\bgi\biI\bIl\bln\bnr\brt\btu\bux\bx] [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ...]
t\bty\byp\bpe\bes\bse\bet\bt [-\b-a\baA\bAf\bfF\bFg\bgi\biI\bIl\bln\bnr\brt\btu\bux\bx] [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ...]
- Declare variables and/or give them attributes. If no _\bn_\ba_\bm_\bes are
- given then display the values of variables. The -\b-p\bp option will
- display the attributes and values of each _\bn_\ba_\bm_\be. When -\b-p\bp is used
+ Declare variables and/or give them attributes. If no _\bn_\ba_\bm_\bes are
+ given then display the values of variables. The -\b-p\bp option will
+ display the attributes and values of each _\bn_\ba_\bm_\be. When -\b-p\bp is used
with _\bn_\ba_\bm_\be arguments, additional options, other than -\b-f\bf and -\b-F\bF,
- are ignored. When -\b-p\bp is supplied without _\bn_\ba_\bm_\be arguments, it will
- display the attributes and values of all variables having the
- attributes specified by the additional options. If no other op-
- tions are supplied with -\b-p\bp, d\bde\bec\bcl\bla\bar\bre\be will display the attributes
- and values of all shell variables. The -\b-f\bf option will restrict
- the display to shell functions. The -\b-F\bF option inhibits the dis-
- play of function definitions; only the function name and at-
- tributes are printed. If the e\bex\bxt\btd\bde\beb\bbu\bug\bg shell option is enabled
+ are ignored. When -\b-p\bp is supplied without _\bn_\ba_\bm_\be arguments, it
+ will display the attributes and values of all variables having
+ the attributes specified by the additional options. If no other
+ options are supplied with -\b-p\bp, d\bde\bec\bcl\bla\bar\bre\be will display the at-
+ tributes and values of all shell variables. The -\b-f\bf option will
+ restrict the display to shell functions. The -\b-F\bF option inhibits
+ the display of function definitions; only the function name and
+ attributes are printed. If the e\bex\bxt\btd\bde\beb\bbu\bug\bg shell option is enabled
using s\bsh\bho\bop\bpt\bt, the source file name and line number where each
- _\bn_\ba_\bm_\be is defined are displayed as well. The -\b-F\bF option implies -\b-f\bf.
- The -\b-g\bg option forces variables to be created or modified at the
- global scope, even when d\bde\bec\bcl\bla\bar\bre\be is executed in a shell function.
- It is ignored in all other cases. The -\b-I\bI option causes local
- variables to inherit the attributes (except the _\bn_\ba_\bm_\be_\br_\be_\bf attri-
- bute) and value of any existing variable with the same _\bn_\ba_\bm_\be at a
- surrounding scope. If there is no existing variable, the local
- variable is initially unset. The following options can be used
- to restrict output to variables with the specified attribute or
- to give variables attributes:
+ _\bn_\ba_\bm_\be is defined are displayed as well. The -\b-F\bF option implies
+ -\b-f\bf. The -\b-g\bg option forces variables to be created or modified at
+ the global scope, even when d\bde\bec\bcl\bla\bar\bre\be is executed in a shell func-
+ tion. It is ignored in all other cases. The -\b-I\bI option causes
+ local variables to inherit the attributes (except the _\bn_\ba_\bm_\be_\br_\be_\bf
+ attribute) and value of any existing variable with the same _\bn_\ba_\bm_\be
+ at a surrounding scope. If there is no existing variable, the
+ local variable is initially unset. The following options can be
+ used to restrict output to variables with the specified attri-
+ bute or to give variables attributes:
-\b-a\ba Each _\bn_\ba_\bm_\be is an indexed array variable (see A\bAr\brr\bra\bay\bys\bs
above).
-\b-A\bA Each _\bn_\ba_\bm_\be is an associative array variable (see A\bAr\brr\bra\bay\bys\bs
tion (see A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN above) is performed when
the variable is assigned a value.
-\b-l\bl When the variable is assigned a value, all upper-case
- characters are converted to lower-case. The upper-case
+ characters are converted to lower-case. The upper-case
attribute is disabled.
-\b-n\bn Give each _\bn_\ba_\bm_\be the _\bn_\ba_\bm_\be_\br_\be_\bf attribute, making it a name
- reference to another variable. That other variable is de-
- fined by the value of _\bn_\ba_\bm_\be. All references, assignments,
- and attribute modifications to _\bn_\ba_\bm_\be, except those using
- or changing the -\b-n\bn attribute itself, are performed on the
- variable referenced by _\bn_\ba_\bm_\be's value. The nameref attri-
- bute cannot be applied to array variables.
- -\b-r\br Make _\bn_\ba_\bm_\bes readonly. These names cannot then be assigned
+ reference to another variable. That other variable is
+ defined by the value of _\bn_\ba_\bm_\be. All references, assign-
+ ments, and attribute modifications to _\bn_\ba_\bm_\be, except those
+ using or changing the -\b-n\bn attribute itself, are performed
+ on the variable referenced by _\bn_\ba_\bm_\be's value. The nameref
+ attribute cannot be applied to array variables.
+ -\b-r\br Make _\bn_\ba_\bm_\bes readonly. These names cannot then be assigned
values by subsequent assignment statements or unset.
- -\b-t\bt Give each _\bn_\ba_\bm_\be the _\bt_\br_\ba_\bc_\be attribute. Traced functions in-
+ -\b-t\bt Give each _\bn_\ba_\bm_\be the _\bt_\br_\ba_\bc_\be attribute. Traced functions in-
herit the D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN traps from the calling shell.
The trace attribute has no special meaning for variables.
-\b-u\bu When the variable is assigned a value, all lower-case
- characters are converted to upper-case. The lower-case
+ characters are converted to upper-case. The lower-case
attribute is disabled.
-\b-x\bx Mark _\bn_\ba_\bm_\bes for export to subsequent commands via the en-
vironment.
Using `+' instead of `-' turns off the attribute instead, with
the exceptions that +\b+a\ba and +\b+A\bA may not be used to destroy array
- variables and +\b+r\br will not remove the readonly attribute. When
+ variables and +\b+r\br will not remove the readonly attribute. When
used in a function, d\bde\bec\bcl\bla\bar\bre\be and t\bty\byp\bpe\bes\bse\bet\bt make each _\bn_\ba_\bm_\be local, as
with the l\blo\boc\bca\bal\bl command, unless the -\b-g\bg option is supplied. If a
variable name is followed by =_\bv_\ba_\bl_\bu_\be, the value of the variable
- is set to _\bv_\ba_\bl_\bu_\be. When using -\b-a\ba or -\b-A\bA and the compound assignment
- syntax to create array variables, additional attributes do not
- take effect until subsequent assignments. The return value is 0
- unless an invalid option is encountered, an attempt is made to
- define a function using ``-f foo=bar'', an attempt is made to
+ is set to _\bv_\ba_\bl_\bu_\be. When using -\b-a\ba or -\b-A\bA and the compound assign-
+ ment syntax to create array variables, additional attributes do
+ not take effect until subsequent assignments. The return value
+ is 0 unless an invalid option is encountered, an attempt is made
+ to define a function using ``-f foo=bar'', an attempt is made to
assign a value to a readonly variable, an attempt is made to as-
sign a value to an array variable without using the compound as-
signment syntax (see A\bAr\brr\bra\bay\bys\bs above), one of the _\bn_\ba_\bm_\be_\bs is not a
d\bdi\bir\brs\bs [\b[-\b-c\bcl\blp\bpv\bv]\b] [\b[+\b+_\bn]\b] [\b[-\b-_\bn]\b]
Without options, displays the list of currently remembered di-
- rectories. The default display is on a single line with direc-
- tory names separated by spaces. Directories are added to the
+ rectories. The default display is on a single line with direc-
+ tory names separated by spaces. Directories are added to the
list with the p\bpu\bus\bsh\bhd\bd command; the p\bpo\bop\bpd\bd command removes entries
- from the list. The current directory is always the first direc-
+ from the list. The current directory is always the first direc-
tory in the stack.
-\b-c\bc Clears the directory stack by deleting all of the en-
tries.
d\bdi\bis\bso\bow\bwn\bn [-\b-a\bar\br] [-\b-h\bh] [_\bj_\bo_\bb_\bs_\bp_\be_\bc ... | _\bp_\bi_\bd ... ]
Without options, remove each _\bj_\bo_\bb_\bs_\bp_\be_\bc from the table of active
- jobs. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, and neither the -\b-a\ba nor the -\b-r\br
- option is supplied, the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. If the -\b-h\bh option is
- given, each _\bj_\bo_\bb_\bs_\bp_\be_\bc is not removed from the table, but is marked
- so that S\bSI\bIG\bGH\bHU\bUP\bP is not sent to the job if the shell receives a
- S\bSI\bIG\bGH\bHU\bUP\bP. If no _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied, the -\b-a\ba option means to remove
- or mark all jobs; the -\b-r\br option without a _\bj_\bo_\bb_\bs_\bp_\be_\bc argument re-
- stricts operation to running jobs. The return value is 0 unless
- a _\bj_\bo_\bb_\bs_\bp_\be_\bc does not specify a valid job.
+ jobs. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, and neither the -\b-a\ba nor the -\b-r\br
+ option is supplied, the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. If the -\b-h\bh option
+ is given, each _\bj_\bo_\bb_\bs_\bp_\be_\bc is not removed from the table, but is
+ marked so that S\bSI\bIG\bGH\bHU\bUP\bP is not sent to the job if the shell re-
+ ceives a S\bSI\bIG\bGH\bHU\bUP\bP. If no _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied, the -\b-a\ba option means
+ to remove or mark all jobs; the -\b-r\br option without a _\bj_\bo_\bb_\bs_\bp_\be_\bc ar-
+ gument restricts operation to running jobs. The return value is
+ 0 unless a _\bj_\bo_\bb_\bs_\bp_\be_\bc does not specify a valid job.
e\bec\bch\bho\bo [-\b-n\bne\beE\bE] [_\ba_\br_\bg ...]
- Output the _\ba_\br_\bgs, separated by spaces, followed by a newline. The
- return status is 0 unless a write error occurs. If -\b-n\bn is speci-
- fied, the trailing newline is suppressed. If the -\b-e\be option is
- given, interpretation of the following backslash-escaped charac-
- ters is enabled. The -\b-E\bE option disables the interpretation of
- these escape characters, even on systems where they are inter-
- preted by default. The x\bxp\bpg\bg_\b_e\bec\bch\bho\bo shell option may be used to dy-
- namically determine whether or not e\bec\bch\bho\bo interprets any options
- and expands these escape characters by default. e\bec\bch\bho\bo does not
- interpret -\b--\b- to mean the end of options. e\bec\bch\bho\bo interprets the
- following escape sequences:
+ Output the _\ba_\br_\bgs, separated by spaces, followed by a newline.
+ The return status is 0 unless a write error occurs. If -\b-n\bn is
+ specified, the trailing newline is suppressed. If the -\b-e\be option
+ is given, interpretation of the following backslash-escaped
+ characters is enabled. The -\b-E\bE option disables the interpreta-
+ tion of these escape characters, even on systems where they are
+ interpreted by default. The x\bxp\bpg\bg_\b_e\bec\bch\bho\bo shell option may be used
+ to dynamically determine whether or not e\bec\bch\bho\bo interprets any op-
+ tions and expands these escape characters by default. e\bec\bch\bho\bo does
+ not interpret -\b--\b- to mean the end of options. e\bec\bch\bho\bo interprets
+ the following escape sequences:
\\b\a\ba alert (bell)
\\b\b\bb backspace
\\b\c\bc suppress further output
hexadecimal value _\bH_\bH_\bH_\bH_\bH_\bH_\bH_\bH (one to eight hex digits)
e\ben\bna\bab\bbl\ble\be [-\b-a\ba] [-\b-d\bdn\bnp\bps\bs] [-\b-f\bf _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be] [_\bn_\ba_\bm_\be ...]
- Enable and disable builtin shell commands. Disabling a builtin
+ Enable and disable builtin shell commands. Disabling a builtin
allows a disk command which has the same name as a shell builtin
to be executed without specifying a full pathname, even though
the shell normally searches for builtins before disk commands.
If -\b-n\bn is used, each _\bn_\ba_\bm_\be is disabled; otherwise, _\bn_\ba_\bm_\be_\bs are en-
- abled. For example, to use the t\bte\bes\bst\bt binary found via the P\bPA\bAT\bTH\bH
+ abled. For example, to use the t\bte\bes\bst\bt binary found via the P\bPA\bAT\bTH\bH
instead of the shell builtin version, run ``enable -n test''.
The -\b-f\bf option means to load the new builtin command _\bn_\ba_\bm_\be from
shared object _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be, on systems that support dynamic loading.
B\bBa\bas\bsh\bh will use the value of the B\bBA\bAS\bSH\bH_\b_L\bLO\bOA\bAD\bDA\bAB\bBL\bLE\bES\bS_\b_P\bPA\bAT\bTH\bH variable as a
colon-separated list of directories in which to search for _\bf_\bi_\bl_\be_\b-
- _\bn_\ba_\bm_\be. The default is system-dependent. The -\b-d\bd option will delete
- a builtin previously loaded with -\b-f\bf. If no _\bn_\ba_\bm_\be arguments are
- given, or if the -\b-p\bp option is supplied, a list of shell builtins
- is printed. With no other option arguments, the list consists of
- all enabled shell builtins. If -\b-n\bn is supplied, only disabled
- builtins are printed. If -\b-a\ba is supplied, the list printed in-
- cludes all builtins, with an indication of whether or not each
- is enabled. If -\b-s\bs is supplied, the output is restricted to the
- POSIX _\bs_\bp_\be_\bc_\bi_\ba_\bl builtins. If no options are supplied and a _\bn_\ba_\bm_\be is
- not a shell builtin, e\ben\bna\bab\bbl\ble\be will attempt to load _\bn_\ba_\bm_\be from a
- shared object named _\bn_\ba_\bm_\be, as if the command were ``enable -f
- _\bn_\ba_\bm_\be _\bn_\ba_\bm_\be . The return value is 0 unless a _\bn_\ba_\bm_\be is not a shell
- builtin or there is an error loading a new builtin from a shared
- object.
+ _\bn_\ba_\bm_\be. The default is system-dependent. The -\b-d\bd option will
+ delete a builtin previously loaded with -\b-f\bf. If no _\bn_\ba_\bm_\be argu-
+ ments are given, or if the -\b-p\bp option is supplied, a list of
+ shell builtins is printed. With no other option arguments, the
+ list consists of all enabled shell builtins. If -\b-n\bn is supplied,
+ only disabled builtins are printed. If -\b-a\ba is supplied, the list
+ printed includes all builtins, with an indication of whether or
+ not each is enabled. If -\b-s\bs is supplied, the output is re-
+ stricted to the POSIX _\bs_\bp_\be_\bc_\bi_\ba_\bl builtins. If no options are sup-
+ plied and a _\bn_\ba_\bm_\be is not a shell builtin, e\ben\bna\bab\bbl\ble\be will attempt to
+ load _\bn_\ba_\bm_\be from a shared object named _\bn_\ba_\bm_\be, as if the command
+ were ``enable -f _\bn_\ba_\bm_\be _\bn_\ba_\bm_\be . The return value is 0 unless a
+ _\bn_\ba_\bm_\be is not a shell builtin or there is an error loading a new
+ builtin from a shared object.
e\bev\bva\bal\bl [_\ba_\br_\bg ...]
The _\ba_\br_\bgs are read and concatenated together into a single com-
- mand. This command is then read and executed by the shell, and
- its exit status is returned as the value of e\bev\bva\bal\bl. If there are
+ mand. This command is then read and executed by the shell, and
+ its exit status is returned as the value of e\bev\bva\bal\bl. If there are
no _\ba_\br_\bg_\bs, or only null arguments, e\bev\bva\bal\bl returns 0.
e\bex\bxe\bec\bc [-\b-c\bcl\bl] [-\b-a\ba _\bn_\ba_\bm_\be] [_\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]]
- If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is specified, it replaces the shell. No new process
- is created. The _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs become the arguments to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. If
+ If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is specified, it replaces the shell. No new process
+ is created. The _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs become the arguments to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. If
the -\b-l\bl option is supplied, the shell places a dash at the begin-
- ning of the zeroth argument passed to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. This is what _\bl_\bo_\b-
- _\bg_\bi_\bn(1) does. The -\b-c\bc option causes _\bc_\bo_\bm_\bm_\ba_\bn_\bd to be executed with an
- empty environment. If -\b-a\ba is supplied, the shell passes _\bn_\ba_\bm_\be as
- the zeroth argument to the executed command. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd cannot
- be executed for some reason, a non-interactive shell exits, un-
- less the e\bex\bxe\bec\bcf\bfa\bai\bil\bl shell option is enabled. In that case, it re-
- turns failure. An interactive shell returns failure if the file
- cannot be executed. A subshell exits unconditionally if e\bex\bxe\bec\bc
- fails. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is not specified, any redirections take effect
- in the current shell, and the return status is 0. If there is a
- redirection error, the return status is 1.
+ ning of the zeroth argument passed to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. This is what _\bl_\bo_\b-
+ _\bg_\bi_\bn(1) does. The -\b-c\bc option causes _\bc_\bo_\bm_\bm_\ba_\bn_\bd to be executed with
+ an empty environment. If -\b-a\ba is supplied, the shell passes _\bn_\ba_\bm_\be
+ as the zeroth argument to the executed command. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd can-
+ not be executed for some reason, a non-interactive shell exits,
+ unless the e\bex\bxe\bec\bcf\bfa\bai\bil\bl shell option is enabled. In that case, it
+ returns failure. An interactive shell returns failure if the
+ file cannot be executed. A subshell exits unconditionally if
+ e\bex\bxe\bec\bc fails. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is not specified, any redirections take
+ effect in the current shell, and the return status is 0. If
+ there is a redirection error, the return status is 1.
e\bex\bxi\bit\bt [_\bn]
- Cause the shell to exit with a status of _\bn. If _\bn is omitted, the
- exit status is that of the last command executed. A trap on E\bEX\bXI\bIT\bT
- is executed before the shell terminates.
+ Cause the shell to exit with a status of _\bn. If _\bn is omitted,
+ the exit status is that of the last command executed. A trap on
+ E\bEX\bXI\bIT\bT is executed before the shell terminates.
e\bex\bxp\bpo\bor\brt\bt [-\b-f\bfn\bn] [_\bn_\ba_\bm_\be[=_\bw_\bo_\br_\bd]] ...
e\bex\bxp\bpo\bor\brt\bt -\b-p\bp
The supplied _\bn_\ba_\bm_\be_\bs are marked for automatic export to the envi-
- ronment of subsequently executed commands. If the -\b-f\bf option is
- given, the _\bn_\ba_\bm_\be_\bs refer to functions. If no _\bn_\ba_\bm_\be_\bs are given, or
+ ronment of subsequently executed commands. If the -\b-f\bf option is
+ given, the _\bn_\ba_\bm_\be_\bs refer to functions. If no _\bn_\ba_\bm_\be_\bs are given, or
if the -\b-p\bp option is supplied, a list of names of all exported
- variables is printed. The -\b-n\bn option causes the export property
- to be removed from each _\bn_\ba_\bm_\be. If a variable name is followed by
- =_\bw_\bo_\br_\bd, the value of the variable is set to _\bw_\bo_\br_\bd. e\bex\bxp\bpo\bor\brt\bt returns
+ variables is printed. The -\b-n\bn option causes the export property
+ to be removed from each _\bn_\ba_\bm_\be. If a variable name is followed by
+ =_\bw_\bo_\br_\bd, the value of the variable is set to _\bw_\bo_\br_\bd. e\bex\bxp\bpo\bor\brt\bt returns
an exit status of 0 unless an invalid option is encountered, one
of the _\bn_\ba_\bm_\be_\bs is not a valid shell variable name, or -\b-f\bf is sup-
plied with a _\bn_\ba_\bm_\be that is not a function.
f\bfc\bc -\b-s\bs [_\bp_\ba_\bt=_\br_\be_\bp] [_\bc_\bm_\bd]
The first form selects a range of commands from _\bf_\bi_\br_\bs_\bt to _\bl_\ba_\bs_\bt
from the history list and displays or edits and re-executes
- them. _\bF_\bi_\br_\bs_\bt and _\bl_\ba_\bs_\bt may be specified as a string (to locate the
- last command beginning with that string) or as a number (an in-
- dex into the history list, where a negative number is used as an
- offset from the current command number). When listing, a _\bf_\bi_\br_\bs_\bt
- or _\bl_\ba_\bs_\bt of 0 is equivalent to -1 and -0 is equivalent to the
- current command (usually the f\bfc\bc command); otherwise 0 is equiva-
- lent to -1 and -0 is invalid. If _\bl_\ba_\bs_\bt is not specified, it is
- set to the current command for listing (so that ``fc -l -10''
- prints the last 10 commands) and to _\bf_\bi_\br_\bs_\bt otherwise. If _\bf_\bi_\br_\bs_\bt is
- not specified, it is set to the previous command for editing and
- -16 for listing.
-
- The -\b-n\bn option suppresses the command numbers when listing. The
- -\b-r\br option reverses the order of the commands. If the -\b-l\bl option
- is given, the commands are listed on standard output. Otherwise,
- the editor given by _\be_\bn_\ba_\bm_\be is invoked on a file containing those
- commands. If _\be_\bn_\ba_\bm_\be is not given, the value of the F\bFC\bCE\bED\bDI\bIT\bT vari-
- able is used, and the value of E\bED\bDI\bIT\bTO\bOR\bR if F\bFC\bCE\bED\bDI\bIT\bT is not set. If
- neither variable is set, _\bv_\bi is used. When editing is complete,
- the edited commands are echoed and executed.
+ them. _\bF_\bi_\br_\bs_\bt and _\bl_\ba_\bs_\bt may be specified as a string (to locate
+ the last command beginning with that string) or as a number (an
+ index into the history list, where a negative number is used as
+ an offset from the current command number). When listing, a
+ _\bf_\bi_\br_\bs_\bt or _\bl_\ba_\bs_\bt of 0 is equivalent to -1 and -0 is equivalent to
+ the current command (usually the f\bfc\bc command); otherwise 0 is
+ equivalent to -1 and -0 is invalid. If _\bl_\ba_\bs_\bt is not specified,
+ it is set to the current command for listing (so that ``fc -l
+ -10'' prints the last 10 commands) and to _\bf_\bi_\br_\bs_\bt otherwise. If
+ _\bf_\bi_\br_\bs_\bt is not specified, it is set to the previous command for
+ editing and -16 for listing.
+
+ The -\b-n\bn option suppresses the command numbers when listing. The
+ -\b-r\br option reverses the order of the commands. If the -\b-l\bl option
+ is given, the commands are listed on standard output. Other-
+ wise, the editor given by _\be_\bn_\ba_\bm_\be is invoked on a file containing
+ those commands. If _\be_\bn_\ba_\bm_\be is not given, the value of the F\bFC\bCE\bED\bDI\bIT\bT
+ variable is used, and the value of E\bED\bDI\bIT\bTO\bOR\bR if F\bFC\bCE\bED\bDI\bIT\bT is not set.
+ If neither variable is set, _\bv_\bi is used. When editing is com-
+ plete, the edited commands are echoed and executed.
In the second form, _\bc_\bo_\bm_\bm_\ba_\bn_\bd is re-executed after each instance
- of _\bp_\ba_\bt is replaced by _\br_\be_\bp. _\bC_\bo_\bm_\bm_\ba_\bn_\bd is interpreted the same as
- _\bf_\bi_\br_\bs_\bt above. A useful alias to use with this is ``r="fc -s"'',
+ of _\bp_\ba_\bt is replaced by _\br_\be_\bp. _\bC_\bo_\bm_\bm_\ba_\bn_\bd is interpreted the same as
+ _\bf_\bi_\br_\bs_\bt above. A useful alias to use with this is ``r="fc -s"'',
so that typing ``r cc'' runs the last command beginning with
``cc'' and typing ``r'' re-executes the last command.
If the first form is used, the return value is 0 unless an in-
valid option is encountered or _\bf_\bi_\br_\bs_\bt or _\bl_\ba_\bs_\bt specify history
- lines out of range. If the -\b-e\be option is supplied, the return
+ lines out of range. If the -\b-e\be option is supplied, the return
value is the value of the last command executed or failure if an
- error occurs with the temporary file of commands. If the second
+ error occurs with the temporary file of commands. If the second
form is used, the return status is that of the command re-exe-
cuted, unless _\bc_\bm_\bd does not specify a valid history line, in
which case f\bfc\bc returns failure.
f\bfg\bg [_\bj_\bo_\bb_\bs_\bp_\be_\bc]
Resume _\bj_\bo_\bb_\bs_\bp_\be_\bc in the foreground, and make it the current job.
If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, the shell's notion of the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb
- is used. The return value is that of the command placed into the
- foreground, or failure if run when job control is disabled or,
- when run with job control enabled, if _\bj_\bo_\bb_\bs_\bp_\be_\bc does not specify a
- valid job or _\bj_\bo_\bb_\bs_\bp_\be_\bc specifies a job that was started without
- job control.
+ is used. The return value is that of the command placed into
+ the foreground, or failure if run when job control is disabled
+ or, when run with job control enabled, if _\bj_\bo_\bb_\bs_\bp_\be_\bc does not spec-
+ ify a valid job or _\bj_\bo_\bb_\bs_\bp_\be_\bc specifies a job that was started
+ without job control.
g\bge\bet\bto\bop\bpt\bts\bs _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg _\bn_\ba_\bm_\be [_\ba_\br_\bg _\b._\b._\b.]
g\bge\bet\bto\bop\bpt\bts\bs is used by shell procedures to parse positional parame-
- ters. _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg contains the option characters to be recognized;
- if a character is followed by a colon, the option is expected to
- have an argument, which should be separated from it by white
- space. The colon and question mark characters may not be used as
- option characters. Each time it is invoked, g\bge\bet\bto\bop\bpt\bts\bs places the
- next option in the shell variable _\bn_\ba_\bm_\be, initializing _\bn_\ba_\bm_\be if it
- does not exist, and the index of the next argument to be pro-
- cessed into the variable O\bOP\bPT\bTI\bIN\bND\bD. O\bOP\bPT\bTI\bIN\bND\bD is initialized to 1 each
- time the shell or a shell script is invoked. When an option re-
- quires an argument, g\bge\bet\bto\bop\bpt\bts\bs places that argument into the vari-
- able O\bOP\bPT\bTA\bAR\bRG\bG. The shell does not reset O\bOP\bPT\bTI\bIN\bND\bD automatically; it
- must be manually reset between multiple calls to g\bge\bet\bto\bop\bpt\bts\bs within
- the same shell invocation if a new set of parameters is to be
- used.
+ ters. _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg contains the option characters to be recog-
+ nized; if a character is followed by a colon, the option is ex-
+ pected to have an argument, which should be separated from it by
+ white space. The colon and question mark characters may not be
+ used as option characters. Each time it is invoked, g\bge\bet\bto\bop\bpt\bts\bs
+ places the next option in the shell variable _\bn_\ba_\bm_\be, initializing
+ _\bn_\ba_\bm_\be if it does not exist, and the index of the next argument to
+ be processed into the variable O\bOP\bPT\bTI\bIN\bND\bD. O\bOP\bPT\bTI\bIN\bND\bD is initialized to
+ 1 each time the shell or a shell script is invoked. When an op-
+ tion requires an argument, g\bge\bet\bto\bop\bpt\bts\bs places that argument into the
+ variable O\bOP\bPT\bTA\bAR\bRG\bG. The shell does not reset O\bOP\bPT\bTI\bIN\bND\bD automatically;
+ it must be manually reset between multiple calls to g\bge\bet\bto\bop\bpt\bts\bs
+ within the same shell invocation if a new set of parameters is
+ to be used.
When the end of options is encountered, g\bge\bet\bto\bop\bpt\bts\bs exits with a re-
- turn value greater than zero. O\bOP\bPT\bTI\bIN\bND\bD is set to the index of the
+ turn value greater than zero. O\bOP\bPT\bTI\bIN\bND\bD is set to the index of the
first non-option argument, and _\bn_\ba_\bm_\be is set to ?.
g\bge\bet\bto\bop\bpt\bts\bs normally parses the positional parameters, but if more
arguments are supplied as _\ba_\br_\bg values, g\bge\bet\bto\bop\bpt\bts\bs parses those in-
stead.
- g\bge\bet\bto\bop\bpt\bts\bs can report errors in two ways. If the first character of
- _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is a colon, _\bs_\bi_\bl_\be_\bn_\bt error reporting is used. In normal
- operation, diagnostic messages are printed when invalid options
- or missing option arguments are encountered. If the variable
- O\bOP\bPT\bTE\bER\bRR\bR is set to 0, no error messages will be displayed, even if
- the first character of _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is not a colon.
+ g\bge\bet\bto\bop\bpt\bts\bs can report errors in two ways. If the first character
+ of _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is a colon, _\bs_\bi_\bl_\be_\bn_\bt error reporting is used. In
+ normal operation, diagnostic messages are printed when invalid
+ options or missing option arguments are encountered. If the
+ variable O\bOP\bPT\bTE\bER\bRR\bR is set to 0, no error messages will be dis-
+ played, even if the first character of _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is not a colon.
If an invalid option is seen, g\bge\bet\bto\bop\bpt\bts\bs places ? into _\bn_\ba_\bm_\be and, if
- not silent, prints an error message and unsets O\bOP\bPT\bTA\bAR\bRG\bG. If
+ not silent, prints an error message and unsets O\bOP\bPT\bTA\bAR\bRG\bG. If
g\bge\bet\bto\bop\bpt\bts\bs is silent, the option character found is placed in O\bOP\bP-\b-
T\bTA\bAR\bRG\bG and no diagnostic message is printed.
If a required argument is not found, and g\bge\bet\bto\bop\bpt\bts\bs is not silent,
a question mark (?\b?) is placed in _\bn_\ba_\bm_\be, O\bOP\bPT\bTA\bAR\bRG\bG is unset, and a
- diagnostic message is printed. If g\bge\bet\bto\bop\bpt\bts\bs is silent, then a
+ diagnostic message is printed. If g\bge\bet\bto\bop\bpt\bts\bs is silent, then a
colon (:\b:) is placed in _\bn_\ba_\bm_\be and O\bOP\bPT\bTA\bAR\bRG\bG is set to the option
character found.
g\bge\bet\bto\bop\bpt\bts\bs returns true if an option, specified or unspecified, is
- found. It returns false if the end of options is encountered or
+ found. It returns false if the end of options is encountered or
an error occurs.
h\bha\bas\bsh\bh [-\b-l\blr\br] [-\b-p\bp _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be] [-\b-d\bdt\bt] [_\bn_\ba_\bm_\be]
Each time h\bha\bas\bsh\bh is invoked, the full pathname of the command _\bn_\ba_\bm_\be
is determined by searching the directories in $\b$P\bPA\bAT\bTH\bH and remem-
- bered. Any previously-remembered pathname is discarded. If the
+ bered. Any previously-remembered pathname is discarded. If the
-\b-p\bp option is supplied, h\bha\bas\bsh\bh uses _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be as the full filename
- of the command. The -\b-r\br option causes the shell to forget all re-
- membered locations. Assigning to the P\bPA\bAT\bTH\bH variable also clears
- all hashed filenames. The -\b-d\bd option causes the shell to forget
- the remembered location of each _\bn_\ba_\bm_\be. If the -\b-t\bt option is sup-
- plied, the full pathname to which each _\bn_\ba_\bm_\be corresponds is
- printed. If multiple _\bn_\ba_\bm_\be arguments are supplied with -\b-t\bt, the
- _\bn_\ba_\bm_\be is printed before the hashed full pathname. The -\b-l\bl option
+ of the command. The -\b-r\br option causes the shell to forget all
+ remembered locations. Assigning to the P\bPA\bAT\bTH\bH variable also
+ clears all hashed filenames. The -\b-d\bd option causes the shell to
+ forget the remembered location of each _\bn_\ba_\bm_\be. If the -\b-t\bt option
+ is supplied, the full pathname to which each _\bn_\ba_\bm_\be corresponds is
+ printed. If multiple _\bn_\ba_\bm_\be arguments are supplied with -\b-t\bt, the
+ _\bn_\ba_\bm_\be is printed before the hashed full pathname. The -\b-l\bl option
causes output to be displayed in a format that may be reused as
- input. If no arguments are given, or if only -\b-l\bl is supplied, in-
- formation about remembered commands is printed. The -\b-t\bt, -\b-d\bd, and
- -\b-p\bp options (the options that act on the _\bn_\ba_\bm_\be arguments) are mu-
- tually exclusive. Only one will be active. If more than one is
- supplied, -\b-t\bt has higher priority than -\b-p\bp, and both are higher
- priority than -\b-d\bd. The return status is true unless a _\bn_\ba_\bm_\be is not
- found or an invalid option is supplied.
+ input. If no arguments are given, or if only -\b-l\bl is supplied,
+ information about remembered commands is printed. The -\b-t\bt, -\b-d\bd,
+ and -\b-p\bp options (the options that act on the _\bn_\ba_\bm_\be arguments) are
+ mutually exclusive. Only one will be active. If more than one
+ is supplied, -\b-t\bt has higher priority than -\b-p\bp, and both are higher
+ priority than -\b-d\bd. The return status is true unless a _\bn_\ba_\bm_\be is
+ not found or an invalid option is supplied.
h\bhe\bel\blp\bp [-\b-d\bdm\bms\bs] [_\bp_\ba_\bt_\bt_\be_\br_\bn]
- Display helpful information about builtin commands. If _\bp_\ba_\bt_\bt_\be_\br_\bn
+ Display helpful information about builtin commands. If _\bp_\ba_\bt_\bt_\be_\br_\bn
is specified, h\bhe\bel\blp\bp gives detailed help on all commands matching
_\bp_\ba_\bt_\bt_\be_\br_\bn; otherwise help for all the builtins and shell control
structures is printed.
h\bhi\bis\bst\bto\bor\bry\by -\b-p\bp _\ba_\br_\bg [_\ba_\br_\bg _\b._\b._\b.]
h\bhi\bis\bst\bto\bor\bry\by -\b-s\bs _\ba_\br_\bg [_\ba_\br_\bg _\b._\b._\b.]
With no options, display the command history list with line num-
- bers. Lines listed with a *\b* have been modified. An argument of _\bn
- lists only the last _\bn lines. If the shell variable H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bR-\b-
- M\bMA\bAT\bT is set and not null, it is used as a format string for _\bs_\bt_\br_\bf_\b-
- _\bt_\bi_\bm_\be(3) to display the time stamp associated with each displayed
- history entry. No intervening blank is printed between the for-
- matted time stamp and the history line. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is supplied,
- it is used as the name of the history file; if not, the value of
- H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is used. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is not supplied and H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is
- unset or null, the -\b-a\ba,\b, -\b-n\bn,\b, -\b-r\br,\b, and -\b-w\bw options have no effect.
- Options, if supplied, have the following meanings:
+ bers. Lines listed with a *\b* have been modified. An argument of
+ _\bn lists only the last _\bn lines. If the shell variable H\bHI\bIS\bST\bTT\bTI\bIM\bME\bE-\b-
+ F\bFO\bOR\bRM\bMA\bAT\bT is set and not null, it is used as a format string for
+ _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3) to display the time stamp associated with each dis-
+ played history entry. No intervening blank is printed between
+ the formatted time stamp and the history line. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is
+ supplied, it is used as the name of the history file; if not,
+ the value of H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is used. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is not supplied and
+ H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is unset or null, the -\b-a\ba,\b, -\b-n\bn,\b, -\b-r\br,\b, and -\b-w\bw options have
+ no effect. Options, if supplied, have the following meanings:
-\b-c\bc Clear the history list by deleting all the entries.
-\b-d\bd _\bo_\bf_\bf_\bs_\be_\bt
- Delete the history entry at position _\bo_\bf_\bf_\bs_\be_\bt. If _\bo_\bf_\bf_\bs_\be_\bt is
- negative, it is interpreted as relative to one greater
+ Delete the history entry at position _\bo_\bf_\bf_\bs_\be_\bt. If _\bo_\bf_\bf_\bs_\be_\bt
+ is negative, it is interpreted as relative to one greater
than the last history position, so negative indices count
back from the end of the history, and an index of -1
refers to the current h\bhi\bis\bst\bto\bor\bry\by -\b-d\bd command.
-\b-d\bd _\bs_\bt_\ba_\br_\bt-_\be_\bn_\bd
Delete the range of history entries between positions
- _\bs_\bt_\ba_\br_\bt and _\be_\bn_\bd, inclusive. Positive and negative values
+ _\bs_\bt_\ba_\br_\bt and _\be_\bn_\bd, inclusive. Positive and negative values
for _\bs_\bt_\ba_\br_\bt and _\be_\bn_\bd are interpreted as described above.
-\b-a\ba Append the ``new'' history lines to the history file.
These are history lines entered since the beginning of
the current b\bba\bas\bsh\bh session, but not already appended to the
history file.
-\b-n\bn Read the history lines not already read from the history
- file into the current history list. These are lines ap-
+ file into the current history list. These are lines ap-
pended to the history file since the beginning of the
current b\bba\bas\bsh\bh session.
-\b-r\br Read the contents of the history file and append them to
-\b-w\bw Write the current history list to the history file, over-
writing the history file's contents.
-\b-p\bp Perform history substitution on the following _\ba_\br_\bg_\bs and
- display the result on the standard output. Does not store
- the results in the history list. Each _\ba_\br_\bg must be quoted
- to disable normal history expansion.
- -\b-s\bs Store the _\ba_\br_\bg_\bs in the history list as a single entry. The
- last command in the history list is removed before the
- _\ba_\br_\bg_\bs are added.
+ display the result on the standard output. Does not
+ store the results in the history list. Each _\ba_\br_\bg must be
+ quoted to disable normal history expansion.
+ -\b-s\bs Store the _\ba_\br_\bg_\bs in the history list as a single entry.
+ The last command in the history list is removed before
+ the _\ba_\br_\bg_\bs are added.
If the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable is set, the time stamp informa-
tion associated with each history entry is written to the his-
tory file, marked with the history comment character. When the
history file is read, lines beginning with the history comment
character followed immediately by a digit are interpreted as
- timestamps for the following history entry. The return value is
+ timestamps for the following history entry. The return value is
0 unless an invalid option is encountered, an error occurs while
reading or writing the history file, an invalid _\bo_\bf_\bf_\bs_\be_\bt or range
is supplied as an argument to -\b-d\bd, or the history expansion sup-
j\bjo\bob\bbs\bs [-\b-l\bln\bnp\bpr\brs\bs] [ _\bj_\bo_\bb_\bs_\bp_\be_\bc ... ]
j\bjo\bob\bbs\bs -\b-x\bx _\bc_\bo_\bm_\bm_\ba_\bn_\bd [ _\ba_\br_\bg_\bs ... ]
- The first form lists the active jobs. The options have the fol-
+ The first form lists the active jobs. The options have the fol-
lowing meanings:
-\b-l\bl List process IDs in addition to the normal information.
-\b-n\bn Display information only about jobs that have changed
-\b-s\bs Display only stopped jobs.
If _\bj_\bo_\bb_\bs_\bp_\be_\bc is given, output is restricted to information about
- that job. The return status is 0 unless an invalid option is en-
- countered or an invalid _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied.
+ that job. The return status is 0 unless an invalid option is
+ encountered or an invalid _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied.
If the -\b-x\bx option is supplied, j\bjo\bob\bbs\bs replaces any _\bj_\bo_\bb_\bs_\bp_\be_\bc found in
_\bc_\bo_\bm_\bm_\ba_\bn_\bd or _\ba_\br_\bg_\bs with the corresponding process group ID, and ex-
k\bki\bil\bll\bl [-\b-s\bs _\bs_\bi_\bg_\bs_\bp_\be_\bc | -\b-n\bn _\bs_\bi_\bg_\bn_\bu_\bm | -\b-_\bs_\bi_\bg_\bs_\bp_\be_\bc] [_\bp_\bi_\bd | _\bj_\bo_\bb_\bs_\bp_\be_\bc] ...
k\bki\bil\bll\bl -\b-l\bl|-\b-L\bL [_\bs_\bi_\bg_\bs_\bp_\be_\bc | _\be_\bx_\bi_\bt_\b__\bs_\bt_\ba_\bt_\bu_\bs]
Send the signal named by _\bs_\bi_\bg_\bs_\bp_\be_\bc or _\bs_\bi_\bg_\bn_\bu_\bm to the processes
- named by _\bp_\bi_\bd or _\bj_\bo_\bb_\bs_\bp_\be_\bc. _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a case-insensitive
+ named by _\bp_\bi_\bd or _\bj_\bo_\bb_\bs_\bp_\be_\bc. _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a case-insensitive
signal name such as S\bSI\bIG\bGK\bKI\bIL\bLL\bL (with or without the S\bSI\bIG\bG prefix) or
- a signal number; _\bs_\bi_\bg_\bn_\bu_\bm is a signal number. If _\bs_\bi_\bg_\bs_\bp_\be_\bc is not
- present, then S\bSI\bIG\bGT\bTE\bER\bRM\bM is assumed. An argument of -\b-l\bl lists the
- signal names. If any arguments are supplied when -\b-l\bl is given,
+ a signal number; _\bs_\bi_\bg_\bn_\bu_\bm is a signal number. If _\bs_\bi_\bg_\bs_\bp_\be_\bc is not
+ present, then S\bSI\bIG\bGT\bTE\bER\bRM\bM is assumed. An argument of -\b-l\bl lists the
+ signal names. If any arguments are supplied when -\b-l\bl is given,
the names of the signals corresponding to the arguments are
- listed, and the return status is 0. The _\be_\bx_\bi_\bt_\b__\bs_\bt_\ba_\bt_\bu_\bs argument to
+ listed, and the return status is 0. The _\be_\bx_\bi_\bt_\b__\bs_\bt_\ba_\bt_\bu_\bs argument to
-\b-l\bl is a number specifying either a signal number or the exit
- status of a process terminated by a signal. The -\b-L\bL option is
- equivalent to -\b-l\bl. k\bki\bil\bll\bl returns true if at least one signal was
+ status of a process terminated by a signal. The -\b-L\bL option is
+ equivalent to -\b-l\bl. k\bki\bil\bll\bl returns true if at least one signal was
successfully sent, or false if an error occurs or an invalid op-
tion is encountered.
l\ble\bet\bt _\ba_\br_\bg [_\ba_\br_\bg ...]
Each _\ba_\br_\bg is an arithmetic expression to be evaluated (see A\bAR\bRI\bIT\bTH\bH-\b-
- M\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN above). If the last _\ba_\br_\bg evaluates to 0, l\ble\bet\bt re-
- turns 1; 0 is returned otherwise.
+ M\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN above). If the last _\ba_\br_\bg evaluates to 0, l\ble\bet\bt
+ returns 1; 0 is returned otherwise.
l\blo\boc\bca\bal\bl [_\bo_\bp_\bt_\bi_\bo_\bn] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ... | - ]
For each argument, a local variable named _\bn_\ba_\bm_\be is created, and
- assigned _\bv_\ba_\bl_\bu_\be. The _\bo_\bp_\bt_\bi_\bo_\bn can be any of the options accepted by
- d\bde\bec\bcl\bla\bar\bre\be. When l\blo\boc\bca\bal\bl is used within a function, it causes the
+ assigned _\bv_\ba_\bl_\bu_\be. The _\bo_\bp_\bt_\bi_\bo_\bn can be any of the options accepted
+ by d\bde\bec\bcl\bla\bar\bre\be. When l\blo\boc\bca\bal\bl is used within a function, it causes the
variable _\bn_\ba_\bm_\be to have a visible scope restricted to that func-
- tion and its children. If _\bn_\ba_\bm_\be is -, the set of shell options is
- made local to the function in which l\blo\boc\bca\bal\bl is invoked: shell op-
- tions changed using the s\bse\bet\bt builtin inside the function after
+ tion and its children. If _\bn_\ba_\bm_\be is -, the set of shell options
+ is made local to the function in which l\blo\boc\bca\bal\bl is invoked: shell
+ options changed using the s\bse\bet\bt builtin inside the function after
the call to l\blo\boc\bca\bal\bl are restored to their original values when the
- function returns. The restore is effected as if a series of s\bse\bet\bt
+ function returns. The restore is effected as if a series of s\bse\bet\bt
commands were executed to restore the values that were in place
- before the function. With no operands, l\blo\boc\bca\bal\bl writes a list of
- local variables to the standard output. It is an error to use
- l\blo\boc\bca\bal\bl when not within a function. The return status is 0 unless
+ before the function. With no operands, l\blo\boc\bca\bal\bl writes a list of
+ local variables to the standard output. It is an error to use
+ l\blo\boc\bca\bal\bl when not within a function. The return status is 0 unless
l\blo\boc\bca\bal\bl is used outside a function, an invalid _\bn_\ba_\bm_\be is supplied,
or _\bn_\ba_\bm_\be is a readonly variable.
_\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk] [-\b-c\bc _\bq_\bu_\ba_\bn_\bt_\bu_\bm] [_\ba_\br_\br_\ba_\by]
Read lines from the standard input into the indexed array vari-
able _\ba_\br_\br_\ba_\by, or from file descriptor _\bf_\bd if the -\b-u\bu option is sup-
- plied. The variable M\bMA\bAP\bPF\bFI\bIL\bLE\bE is the default _\ba_\br_\br_\ba_\by. Options, if
+ plied. The variable M\bMA\bAP\bPF\bFI\bIL\bLE\bE is the default _\ba_\br_\br_\ba_\by. Options, if
supplied, have the following meanings:
-\b-d\bd The first character of _\bd_\be_\bl_\bi_\bm is used to terminate each
- input line, rather than newline. If _\bd_\be_\bl_\bi_\bm is the empty
+ input line, rather than newline. If _\bd_\be_\bl_\bi_\bm is the empty
string, m\bma\bap\bpf\bfi\bil\ble\be will terminate a line when it reads a NUL
character.
- -\b-n\bn Copy at most _\bc_\bo_\bu_\bn_\bt lines. If _\bc_\bo_\bu_\bn_\bt is 0, all lines are
+ -\b-n\bn Copy at most _\bc_\bo_\bu_\bn_\bt lines. If _\bc_\bo_\bu_\bn_\bt is 0, all lines are
copied.
- -\b-O\bO Begin assigning to _\ba_\br_\br_\ba_\by at index _\bo_\br_\bi_\bg_\bi_\bn. The default in-
- dex is 0.
+ -\b-O\bO Begin assigning to _\ba_\br_\br_\ba_\by at index _\bo_\br_\bi_\bg_\bi_\bn. The default
+ index is 0.
-\b-s\bs Discard the first _\bc_\bo_\bu_\bn_\bt lines read.
-\b-t\bt Remove a trailing _\bd_\be_\bl_\bi_\bm (default newline) from each line
read.
-\b-u\bu Read lines from file descriptor _\bf_\bd instead of the stan-
dard input.
- -\b-C\bC Evaluate _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk each time _\bq_\bu_\ba_\bn_\bt_\bu_\bm lines are read. The
+ -\b-C\bC Evaluate _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk each time _\bq_\bu_\ba_\bn_\bt_\bu_\bm lines are read. The
-\b-c\bc option specifies _\bq_\bu_\ba_\bn_\bt_\bu_\bm.
-\b-c\bc Specify the number of lines read between each call to
_\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk.
- If -\b-C\bC is specified without -\b-c\bc, the default quantum is 5000. When
- _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated, it is supplied the index of the next ar-
- ray element to be assigned and the line to be assigned to that
- element as additional arguments. _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated after the
- line is read but before the array element is assigned.
+ If -\b-C\bC is specified without -\b-c\bc, the default quantum is 5000.
+ When _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated, it is supplied the index of the next
+ array element to be assigned and the line to be assigned to that
+ element as additional arguments. _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated after
+ the line is read but before the array element is assigned.
If not supplied with an explicit origin, m\bma\bap\bpf\bfi\bil\ble\be will clear _\ba_\br_\b-
_\br_\ba_\by before assigning to it.
_\ba_\br_\br_\ba_\by is not an indexed array.
p\bpo\bop\bpd\bd [-n\bn] [+_\bn] [-_\bn]
- Removes entries from the directory stack. The elements are num-
+ Removes entries from the directory stack. The elements are num-
bered from 0 starting at the first directory listed by d\bdi\bir\brs\bs.
With no arguments, p\bpo\bop\bpd\bd removes the top directory from the
- stack, and changes to the new top directory. Arguments, if sup-
+ stack, and changes to the new top directory. Arguments, if sup-
plied, have the following meanings:
-\b-n\bn Suppresses the normal change of directory when removing
directories from the stack, so that only the stack is ma-
nipulated.
+\b+_\bn Removes the _\bnth entry counting from the left of the list
- shown by d\bdi\bir\brs\bs, starting with zero, from the stack. For
+ shown by d\bdi\bir\brs\bs, starting with zero, from the stack. For
example: ``popd +0'' removes the first directory, ``popd
+1'' the second.
-\b-_\bn Removes the _\bnth entry counting from the right of the list
- shown by d\bdi\bir\brs\bs, starting with zero. For example: ``popd
+ shown by d\bdi\bir\brs\bs, starting with zero. For example: ``popd
-0'' removes the last directory, ``popd -1'' the next to
last.
If the top element of the directory stack is modified, and the
_\b-_\bn option was not supplied, p\bpo\bop\bpd\bd uses the c\bcd\bd builtin to change
- to the directory at the top of the stack. If the c\bcd\bd fails, p\bpo\bop\bpd\bd
+ to the directory at the top of the stack. If the c\bcd\bd fails, p\bpo\bop\bpd\bd
returns a non-zero value.
Otherwise, p\bpo\bop\bpd\bd returns false if an invalid option is encoun-
p\bpr\bri\bin\bnt\btf\bf [-\b-v\bv _\bv_\ba_\br] _\bf_\bo_\br_\bm_\ba_\bt [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
Write the formatted _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs to the standard output under the
- control of the _\bf_\bo_\br_\bm_\ba_\bt. The -\b-v\bv option causes the output to be as-
- signed to the variable _\bv_\ba_\br rather than being printed to the
+ control of the _\bf_\bo_\br_\bm_\ba_\bt. The -\b-v\bv option causes the output to be
+ assigned to the variable _\bv_\ba_\br rather than being printed to the
standard output.
The _\bf_\bo_\br_\bm_\ba_\bt is a character string which contains three types of
objects: plain characters, which are simply copied to standard
output, character escape sequences, which are converted and
copied to the standard output, and format specifications, each
- of which causes printing of the next successive _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt. In ad-
- dition to the standard _\bp_\br_\bi_\bn_\bt_\bf(3) format characters c\bcs\bsn\bnd\bdi\bio\bou\bux\bxX\bXe\beE\bEf\bf-\b-
- F\bFg\bgG\bGa\baA\bA, p\bpr\bri\bin\bnt\btf\bf interprets the following additional format speci-
- fiers:
+ of which causes printing of the next successive _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt. In
+ addition to the standard _\bp_\br_\bi_\bn_\bt_\bf(3) format characters c\bcs\bsn\bnd\bdi\bio\bou\bux\bxX\bXe\be-\b-
+ E\bEf\bfF\bFg\bgG\bGa\baA\bA, p\bpr\bri\bin\bnt\btf\bf interprets the following additional format spec-
+ ifiers:
%\b%b\bb causes p\bpr\bri\bin\bnt\btf\bf to expand backslash escape sequences in the
corresponding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt in the same way as e\bec\bch\bho\bo -\b-e\be.
%\b%q\bq causes p\bpr\bri\bin\bnt\btf\bf to output the corresponding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt in a
- format that can be reused as shell input. %\b%q\bq and %\b%Q\bQ use
+ format that can be reused as shell input. %\b%q\bq and %\b%Q\bQ use
the $\b$'\b''\b' quoting style if any characters in the argument
- string require it, and backslash quoting otherwise. If
+ string require it, and backslash quoting otherwise. If
the format string uses the _\bp_\br_\bi_\bn_\bt_\bf alternate form, these
two formats quote the argument string using single
quotes.
causes p\bpr\bri\bin\bnt\btf\bf to output the date-time string resulting
from using _\bd_\ba_\bt_\be_\bf_\bm_\bt as a format string for _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3).
The corresponding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt is an integer representing the
- number of seconds since the epoch. Two special argument
+ number of seconds since the epoch. Two special argument
values may be used: -1 represents the current time, and
- -2 represents the time the shell was invoked. If no argu-
- ment is specified, conversion behaves as if -1 had been
- given. This is an exception to the usual p\bpr\bri\bin\bnt\btf\bf behavior.
+ -2 represents the time the shell was invoked. If no ar-
+ gument is specified, conversion behaves as if -1 had been
+ given. This is an exception to the usual p\bpr\bri\bin\bnt\btf\bf behav-
+ ior.
The %b, %q, and %T format specifiers all use the field width and
precision arguments from the format specification and write that
- many bytes from (or use that wide a field for) the expanded ar-
- gument, which usually contains more characters than the origi-
+ many bytes from (or use that wide a field for) the expanded ar-
+ gument, which usually contains more characters than the origi-
nal.
The %n format specifier accepts a corresponding argument that is
treated as a shell variable name.
- The %s and %c format specifiers accept an l (long) modifier,
+ The %s and %c format specifiers accept an l (long) modifier,
which forces them to convert the argument string to a wide-char-
acter string and apply any supplied field width and precision in
terms of characters, not bytes.
- Arguments to non-string format specifiers are treated as C con-
+ Arguments to non-string format specifiers are treated as C con-
stants, except that a leading plus or minus sign is allowed, and
- if the leading character is a single or double quote, the value
+ if the leading character is a single or double quote, the value
is the ASCII value of the following character.
- The _\bf_\bo_\br_\bm_\ba_\bt is reused as necessary to consume all of the _\ba_\br_\bg_\bu_\b-
+ The _\bf_\bo_\br_\bm_\ba_\bt is reused as necessary to consume all of the _\ba_\br_\bg_\bu_\b-
_\bm_\be_\bn_\bt_\bs. If the _\bf_\bo_\br_\bm_\ba_\bt requires more _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs than are supplied,
- the extra format specifications behave as if a zero value or
- null string, as appropriate, had been supplied. The return value
- is zero on success, non-zero if an invalid option is supplied or
- a write or assignment error occurs.
+ the extra format specifications behave as if a zero value or
+ null string, as appropriate, had been supplied. The return
+ value is zero on success, non-zero if an invalid option is sup-
+ plied or a write or assignment error occurs.
p\bpu\bus\bsh\bhd\bd [-\b-n\bn] [+_\bn] [-_\bn]
p\bpu\bus\bsh\bhd\bd [-\b-n\bn] [_\bd_\bi_\br]
- Adds a directory to the top of the directory stack, or rotates
- the stack, making the new top of the stack the current working
- directory. With no arguments, p\bpu\bus\bsh\bhd\bd exchanges the top two ele-
- ments of the directory stack. Arguments, if supplied, have the
+ Adds a directory to the top of the directory stack, or rotates
+ the stack, making the new top of the stack the current working
+ directory. With no arguments, p\bpu\bus\bsh\bhd\bd exchanges the top two ele-
+ ments of the directory stack. Arguments, if supplied, have the
following meanings:
- -\b-n\bn Suppresses the normal change of directory when rotating
- or adding directories to the stack, so that only the
+ -\b-n\bn Suppresses the normal change of directory when rotating
+ or adding directories to the stack, so that only the
stack is manipulated.
- +\b+_\bn Rotates the stack so that the _\bnth directory (counting
- from the left of the list shown by d\bdi\bir\brs\bs, starting with
+ +\b+_\bn Rotates the stack so that the _\bnth directory (counting
+ from the left of the list shown by d\bdi\bir\brs\bs, starting with
zero) is at the top.
- -\b-_\bn Rotates the stack so that the _\bnth directory (counting
- from the right of the list shown by d\bdi\bir\brs\bs, starting with
+ -\b-_\bn Rotates the stack so that the _\bnth directory (counting
+ from the right of the list shown by d\bdi\bir\brs\bs, starting with
zero) is at the top.
_\bd_\bi_\br Adds _\bd_\bi_\br to the directory stack at the top
After the stack has been modified, if the -\b-n\bn option was not sup-
- plied, p\bpu\bus\bsh\bhd\bd uses the c\bcd\bd builtin to change to the directory at
- the top of the stack. If the c\bcd\bd fails, p\bpu\bus\bsh\bhd\bd returns a non-zero
+ plied, p\bpu\bus\bsh\bhd\bd uses the c\bcd\bd builtin to change to the directory at
+ the top of the stack. If the c\bcd\bd fails, p\bpu\bus\bsh\bhd\bd returns a non-zero
value.
- Otherwise, if no arguments are supplied, p\bpu\bus\bsh\bhd\bd returns 0 unless
- the directory stack is empty. When rotating the directory stack,
- p\bpu\bus\bsh\bhd\bd returns 0 unless the directory stack is empty or a non-ex-
- istent directory stack element is specified.
+ Otherwise, if no arguments are supplied, p\bpu\bus\bsh\bhd\bd returns 0 unless
+ the directory stack is empty. When rotating the directory
+ stack, p\bpu\bus\bsh\bhd\bd returns 0 unless the directory stack is empty or a
+ non-existent directory stack element is specified.
- If the p\bpu\bus\bsh\bhd\bd command is successful, bash runs d\bdi\bir\brs\bs to show the
+ If the p\bpu\bus\bsh\bhd\bd command is successful, bash runs d\bdi\bir\brs\bs to show the
final contents of the directory stack.
p\bpw\bwd\bd [-\b-L\bLP\bP]
- Print the absolute pathname of the current working directory.
+ Print the absolute pathname of the current working directory.
The pathname printed contains no symbolic links if the -\b-P\bP option
is supplied or the -\b-o\bo p\bph\bhy\bys\bsi\bic\bca\bal\bl option to the s\bse\bet\bt builtin command
- is enabled. If the -\b-L\bL option is used, the pathname printed may
- contain symbolic links. The return status is 0 unless an error
+ is enabled. If the -\b-L\bL option is used, the pathname printed may
+ contain symbolic links. The return status is 0 unless an error
occurs while reading the name of the current directory or an in-
valid option is supplied.
- r\bre\bea\bad\bd [-\b-E\bEe\ber\brs\bs] [-\b-a\ba _\ba_\bn_\ba_\bm_\be] [-\b-d\bd _\bd_\be_\bl_\bi_\bm] [-\b-i\bi _\bt_\be_\bx_\bt] [-\b-n\bn _\bn_\bc_\bh_\ba_\br_\bs] [-\b-N\bN _\bn_\bc_\bh_\ba_\br_\bs]
+ r\bre\bea\bad\bd [-\b-E\bEe\ber\brs\bs] [-\b-a\ba _\ba_\bn_\ba_\bm_\be] [-\b-d\bd _\bd_\be_\bl_\bi_\bm] [-\b-i\bi _\bt_\be_\bx_\bt] [-\b-n\bn _\bn_\bc_\bh_\ba_\br_\bs] [-\b-N\bN _\bn_\bc_\bh_\ba_\br_\bs]
[-\b-p\bp _\bp_\br_\bo_\bm_\bp_\bt] [-\b-t\bt _\bt_\bi_\bm_\be_\bo_\bu_\bt] [-\b-u\bu _\bf_\bd] [_\bn_\ba_\bm_\be ...]
- One line is read from the standard input, or from the file de-
+ One line is read from the standard input, or from the file de-
scriptor _\bf_\bd supplied as an argument to the -\b-u\bu option, split into
- words as described above under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg, and the first
- word is assigned to the first _\bn_\ba_\bm_\be, the second word to the sec-
- ond _\bn_\ba_\bm_\be, and so on. If there are more words than names, the re-
- maining words and their intervening delimiters are assigned to
- the last _\bn_\ba_\bm_\be. If there are fewer words read from the input
- stream than names, the remaining names are assigned empty val-
- ues. The characters in I\bIF\bFS\bS are used to split the line into words
- using the same rules the shell uses for expansion (described
- above under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg). The backslash character (\\b\) may be
- used to remove any special meaning for the next character read
- and for line continuation. Options, if supplied, have the fol-
- lowing meanings:
+ words as described above under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg, and the first
+ word is assigned to the first _\bn_\ba_\bm_\be, the second word to the sec-
+ ond _\bn_\ba_\bm_\be, and so on. If there are more words than names, the
+ remaining words and their intervening delimiters are assigned to
+ the last _\bn_\ba_\bm_\be. If there are fewer words read from the input
+ stream than names, the remaining names are assigned empty val-
+ ues. The characters in I\bIF\bFS\bS are used to split the line into
+ words using the same rules the shell uses for expansion (de-
+ scribed above under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg). The backslash character
+ (\\b\) may be used to remove any special meaning for the next char-
+ acter read and for line continuation. Options, if supplied,
+ have the following meanings:
-\b-a\ba _\ba_\bn_\ba_\bm_\be
The words are assigned to sequential indices of the array
- variable _\ba_\bn_\ba_\bm_\be, starting at 0. _\ba_\bn_\ba_\bm_\be is unset before any
- new values are assigned. Other _\bn_\ba_\bm_\be arguments are ig-
+ variable _\ba_\bn_\ba_\bm_\be, starting at 0. _\ba_\bn_\ba_\bm_\be is unset before any
+ new values are assigned. Other _\bn_\ba_\bm_\be arguments are ig-
nored.
-\b-d\bd _\bd_\be_\bl_\bi_\bm
The first character of _\bd_\be_\bl_\bi_\bm is used to terminate the in-
- put line, rather than newline. If _\bd_\be_\bl_\bi_\bm is the empty
- string, r\bre\bea\bad\bd will terminate a line when it reads a NUL
+ put line, rather than newline. If _\bd_\be_\bl_\bi_\bm is the empty
+ string, r\bre\bea\bad\bd will terminate a line when it reads a NUL
character.
- -\b-e\be If the standard input is coming from a terminal, r\bre\bea\bad\bd
- uses r\bre\bea\bad\bdl\bli\bin\bne\be (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE above) to obtain the line.
- Readline uses the current (or default, if line editing
- was not previously active) editing settings, but uses
+ -\b-e\be If the standard input is coming from a terminal, r\bre\bea\bad\bd
+ uses r\bre\bea\bad\bdl\bli\bin\bne\be (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE above) to obtain the line.
+ Readline uses the current (or default, if line editing
+ was not previously active) editing settings, but uses
readline's default filename completion.
- -\b-E\bE If the standard input is coming from a terminal, r\bre\bea\bad\bd
- uses r\bre\bea\bad\bdl\bli\bin\bne\be (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE above) to obtain the line.
- Readline uses the current (or default, if line editing
- was not previously active) editing settings, but uses
+ -\b-E\bE If the standard input is coming from a terminal, r\bre\bea\bad\bd
+ uses r\bre\bea\bad\bdl\bli\bin\bne\be (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE above) to obtain the line.
+ Readline uses the current (or default, if line editing
+ was not previously active) editing settings, but uses
bash's default completion, including programmable comple-
tion.
-\b-i\bi _\bt_\be_\bx_\bt
- If r\bre\bea\bad\bdl\bli\bin\bne\be is being used to read the line, _\bt_\be_\bx_\bt is
+ If r\bre\bea\bad\bdl\bli\bin\bne\be is being used to read the line, _\bt_\be_\bx_\bt is
placed into the editing buffer before editing begins.
-\b-n\bn _\bn_\bc_\bh_\ba_\br_\bs
- r\bre\bea\bad\bd returns after reading _\bn_\bc_\bh_\ba_\br_\bs characters rather than
+ r\bre\bea\bad\bd returns after reading _\bn_\bc_\bh_\ba_\br_\bs characters rather than
waiting for a complete line of input, but honors a delim-
- iter if fewer than _\bn_\bc_\bh_\ba_\br_\bs characters are read before the
+ iter if fewer than _\bn_\bc_\bh_\ba_\br_\bs characters are read before the
delimiter.
-\b-N\bN _\bn_\bc_\bh_\ba_\br_\bs
- r\bre\bea\bad\bd returns after reading exactly _\bn_\bc_\bh_\ba_\br_\bs characters
- rather than waiting for a complete line of input, unless
- EOF is encountered or r\bre\bea\bad\bd times out. Delimiter charac-
- ters encountered in the input are not treated specially
- and do not cause r\bre\bea\bad\bd to return until _\bn_\bc_\bh_\ba_\br_\bs characters
- are read. The result is not split on the characters in
- I\bIF\bFS\bS; the intent is that the variable is assigned exactly
+ r\bre\bea\bad\bd returns after reading exactly _\bn_\bc_\bh_\ba_\br_\bs characters
+ rather than waiting for a complete line of input, unless
+ EOF is encountered or r\bre\bea\bad\bd times out. Delimiter charac-
+ ters encountered in the input are not treated specially
+ and do not cause r\bre\bea\bad\bd to return until _\bn_\bc_\bh_\ba_\br_\bs characters
+ are read. The result is not split on the characters in
+ I\bIF\bFS\bS; the intent is that the variable is assigned exactly
the characters read (with the exception of backslash; see
the -\b-r\br option below).
-\b-p\bp _\bp_\br_\bo_\bm_\bp_\bt
Display _\bp_\br_\bo_\bm_\bp_\bt on standard error, without a trailing new-
- line, before attempting to read any input. The prompt is
+ line, before attempting to read any input. The prompt is
displayed only if input is coming from a terminal.
- -\b-r\br Backslash does not act as an escape character. The back-
- slash is considered to be part of the line. In particu-
- lar, a backslash-newline pair may not then be used as a
+ -\b-r\br Backslash does not act as an escape character. The back-
+ slash is considered to be part of the line. In particu-
+ lar, a backslash-newline pair may not then be used as a
line continuation.
- -\b-s\bs Silent mode. If input is coming from a terminal, charac-
+ -\b-s\bs Silent mode. If input is coming from a terminal, charac-
ters are not echoed.
-\b-t\bt _\bt_\bi_\bm_\be_\bo_\bu_\bt
- Cause r\bre\bea\bad\bd to time out and return failure if a complete
- line of input (or a specified number of characters) is
- not read within _\bt_\bi_\bm_\be_\bo_\bu_\bt seconds. _\bt_\bi_\bm_\be_\bo_\bu_\bt may be a decimal
- number with a fractional portion following the decimal
- point. This option is only effective if r\bre\bea\bad\bd is reading
- input from a terminal, pipe, or other special file; it
- has no effect when reading from regular files. If r\bre\bea\bad\bd
- times out, r\bre\bea\bad\bd saves any partial input read into the
- specified variable _\bn_\ba_\bm_\be. If _\bt_\bi_\bm_\be_\bo_\bu_\bt is 0, r\bre\bea\bad\bd returns
- immediately, without trying to read any data. The exit
- status is 0 if input is available on the specified file
- descriptor, or the read will return EOF, non-zero other-
- wise. The exit status is greater than 128 if the timeout
- is exceeded.
+ Cause r\bre\bea\bad\bd to time out and return failure if a complete
+ line of input (or a specified number of characters) is
+ not read within _\bt_\bi_\bm_\be_\bo_\bu_\bt seconds. _\bt_\bi_\bm_\be_\bo_\bu_\bt may be a deci-
+ mal number with a fractional portion following the deci-
+ mal point. This option is only effective if r\bre\bea\bad\bd is
+ reading input from a terminal, pipe, or other special
+ file; it has no effect when reading from regular files.
+ If r\bre\bea\bad\bd times out, r\bre\bea\bad\bd saves any partial input read into
+ the specified variable _\bn_\ba_\bm_\be. If _\bt_\bi_\bm_\be_\bo_\bu_\bt is 0, r\bre\bea\bad\bd re-
+ turns immediately, without trying to read any data. The
+ exit status is 0 if input is available on the specified
+ file descriptor, or the read will return EOF, non-zero
+ otherwise. The exit status is greater than 128 if the
+ timeout is exceeded.
-\b-u\bu _\bf_\bd Read input from file descriptor _\bf_\bd.
- If no _\bn_\ba_\bm_\be_\bs are supplied, the line read, without the ending de-
- limiter but otherwise unmodified, is assigned to the variable
- R\bRE\bEP\bPL\bLY\bY. The exit status is zero, unless end-of-file is encoun-
- tered, r\bre\bea\bad\bd times out (in which case the status is greater than
- 128), a variable assignment error (such as assigning to a read-
+ If no _\bn_\ba_\bm_\be_\bs are supplied, the line read, without the ending de-
+ limiter but otherwise unmodified, is assigned to the variable
+ R\bRE\bEP\bPL\bLY\bY. The exit status is zero, unless end-of-file is encoun-
+ tered, r\bre\bea\bad\bd times out (in which case the status is greater than
+ 128), a variable assignment error (such as assigning to a read-
only variable) occurs, or an invalid file descriptor is supplied
as the argument to -\b-u\bu.
r\bre\bea\bad\bdo\bon\bnl\bly\by [-\b-a\baA\bAf\bf] [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bw_\bo_\br_\bd] ...]
- The given _\bn_\ba_\bm_\be_\bs are marked readonly; the values of these _\bn_\ba_\bm_\be_\bs
- may not be changed by subsequent assignment. If the -\b-f\bf option is
- supplied, the functions corresponding to the _\bn_\ba_\bm_\be_\bs are so
- marked. The -\b-a\ba option restricts the variables to indexed arrays;
- the -\b-A\bA option restricts the variables to associative arrays. If
- both options are supplied, -\b-A\bA takes precedence. If no _\bn_\ba_\bm_\be argu-
- ments are given, or if the -\b-p\bp option is supplied, a list of all
- readonly names is printed. The other options may be used to re-
- strict the output to a subset of the set of readonly names. The
- -\b-p\bp option causes output to be displayed in a format that may be
- reused as input. If a variable name is followed by =_\bw_\bo_\br_\bd, the
- value of the variable is set to _\bw_\bo_\br_\bd. The return status is 0 un-
- less an invalid option is encountered, one of the _\bn_\ba_\bm_\be_\bs is not a
- valid shell variable name, or -\b-f\bf is supplied with a _\bn_\ba_\bm_\be that is
- not a function.
+ The given _\bn_\ba_\bm_\be_\bs are marked readonly; the values of these _\bn_\ba_\bm_\be_\bs
+ may not be changed by subsequent assignment. If the -\b-f\bf option
+ is supplied, the functions corresponding to the _\bn_\ba_\bm_\be_\bs are so
+ marked. The -\b-a\ba option restricts the variables to indexed ar-
+ rays; the -\b-A\bA option restricts the variables to associative ar-
+ rays. If both options are supplied, -\b-A\bA takes precedence. If no
+ _\bn_\ba_\bm_\be arguments are given, or if the -\b-p\bp 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 -\b-p\bp option causes output to be displayed in a format
+ that may be reused as input. If a variable name is followed by
+ =_\bw_\bo_\br_\bd, the value of the variable is set to _\bw_\bo_\br_\bd. The return
+ status is 0 unless an invalid option is encountered, one of the
+ _\bn_\ba_\bm_\be_\bs is not a valid shell variable name, or -\b-f\bf is supplied with
+ a _\bn_\ba_\bm_\be that is not a function.
r\bre\bet\btu\bur\brn\bn [_\bn]
- Causes a function to stop executing and return the value speci-
- fied by _\bn to its caller. If _\bn is omitted, the return status is
- that of the last command executed in the function body. If r\bre\be-\b-
+ Causes a function to stop executing and return the value speci-
+ fied by _\bn to its caller. If _\bn is omitted, the return status is
+ that of the last command executed in the function body. If r\bre\be-\b-
t\btu\bur\brn\bn is executed by a trap handler, the last command used to de-
- termine the status is the last command executed before the trap
- handler. If r\bre\bet\btu\bur\brn\bn is executed during a D\bDE\bEB\bBU\bUG\bG trap, the last
- command used to determine the status is the last command exe-
- cuted by the trap handler before r\bre\bet\btu\bur\brn\bn was invoked. If r\bre\bet\btu\bur\brn\bn
- is used outside a function, but during execution of a script by
- the .\b. (s\bso\bou\bur\brc\bce\be) command, it causes the shell to stop executing
- that script and return either _\bn or the exit status of the last
- command executed within the script as the exit status of the
- script. If _\bn is supplied, the return value is its least signifi-
- cant 8 bits. The return status is non-zero if r\bre\bet\btu\bur\brn\bn is supplied
- a non-numeric argument, or is used outside a function and not
- during execution of a script by .\b. or s\bso\bou\bur\brc\bce\be. Any command associ-
- ated with the R\bRE\bET\bTU\bUR\bRN\bN trap is executed before execution resumes
- after the function or script.
+ termine the status is the last command executed before the trap
+ handler. If r\bre\bet\btu\bur\brn\bn is executed during a D\bDE\bEB\bBU\bUG\bG trap, the last
+ command used to determine the status is the last command exe-
+ cuted by the trap handler before r\bre\bet\btu\bur\brn\bn was invoked. If r\bre\bet\btu\bur\brn\bn
+ is used outside a function, but during execution of a script by
+ the .\b. (s\bso\bou\bur\brc\bce\be) command, it causes the shell to stop executing
+ that script and return either _\bn or the exit status of the last
+ command executed within the script as the exit status of the
+ script. If _\bn is supplied, the return value is its least signif-
+ icant 8 bits. The return status is non-zero if r\bre\bet\btu\bur\brn\bn is sup-
+ plied a non-numeric argument, or is used outside a function and
+ not during execution of a script by .\b. or s\bso\bou\bur\brc\bce\be. Any command
+ associated with the R\bRE\bET\bTU\bUR\bRN\bN trap is executed before execution re-
+ sumes after the function or script.
s\bse\bet\bt [-\b-a\bab\bbe\bef\bfh\bhk\bkm\bmn\bnp\bpt\btu\buv\bvx\bxB\bBC\bCE\bEH\bHP\bPT\bT] [-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be] [-\b--\b-] [-\b-] [_\ba_\br_\bg ...]
s\bse\bet\bt [+\b+a\bab\bbe\bef\bfh\bhk\bkm\bmn\bnp\bpt\btu\buv\bvx\bxB\bBC\bCE\bEH\bHP\bPT\bT] [+\b+o\bo _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be] [-\b--\b-] [-\b-] [_\ba_\br_\bg ...]
s\bse\bet\bt -\b-o\bo
- s\bse\bet\bt +\b+o\bo Without options, display the name and value of each shell vari-
- able in a format that can be reused as input for setting or re-
- setting the currently-set variables. Read-only variables cannot
- be reset. In _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, 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 values for the
- positional parameters and are assigned, in order, to $\b$1\b1, $\b$2\b2, .\b..\b..\b.
- $\b$_\bn. Options, if specified, have the following meanings:
+ s\bse\bet\bt +\b+o\bo Without options, display the name and value of each shell vari-
+ able in a format that can be reused as input for setting or re-
+ setting the currently-set variables. Read-only variables cannot
+ be reset. In _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, 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 argu-
+ ments remaining after option processing are treated as values
+ for the positional parameters and are assigned, in order, to $\b$1\b1,
+ $\b$2\b2, .\b..\b..\b. $\b$_\bn. Options, if specified, have the following mean-
+ ings:
-\b-a\ba Each variable or function that is created or modified is
given the export attribute and marked for export to the
environment of subsequent commands.
e\bel\bli\bif\bf reserved words, part of any command executed in a
&\b&&\b& or |\b||\b| list except the command following the final &\b&&\b&
or |\b||\b|, any command in a pipeline but the last, or if the
- command's return value is being inverted with !\b!. If a
+ command's return value is being inverted with !\b!. If a
compound command other than a subshell returns a non-
zero status because a command failed while -\b-e\be was being
- ignored, the shell does not exit. A trap on E\bER\bRR\bR, if set,
- is executed before the shell exits. This option applies
- to the shell environment and each subshell environment
- separately (see C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT above),
- and may cause subshells to exit before executing all the
- commands in the subshell.
+ ignored, the shell does not exit. A trap on E\bER\bRR\bR, if
+ set, is executed before the shell exits. This option
+ applies to the shell environment and each subshell envi-
+ ronment separately (see C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT
+ above), and may cause subshells to exit before executing
+ all the commands in the subshell.
If a compound command or shell function executes in a
context where -\b-e\be is being ignored, none of the commands
containing the function call completes.
-\b-f\bf Disable pathname expansion.
-\b-h\bh Remember the location of commands as they are looked up
- for execution. This is enabled by default.
+ for execution. This is enabled by default.
-\b-k\bk All arguments in the form of assignment statements are
placed in the environment for a command, not just those
that precede the command name.
- -\b-m\bm Monitor mode. Job control is enabled. This option is on
- by default for interactive shells on systems that sup-
- port it (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL above). All processes run in a
- separate process group. When a background job completes,
- the shell prints a line containing its exit status.
- -\b-n\bn Read commands but do not execute them. This may be used
- to check a shell script for syntax errors. This is ig-
+ -\b-m\bm Monitor mode. Job control is enabled. This option is
+ on by default for interactive shells on systems that
+ support it (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL 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.
+ -\b-n\bn Read commands but do not execute them. This may be used
+ to check a shell script for syntax errors. This is ig-
nored by interactive shells.
-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be
The _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be can be one of the following:
Same as -\b-a\ba.
b\bbr\bra\bac\bce\bee\bex\bxp\bpa\ban\bnd\bd
Same as -\b-B\bB.
- e\bem\bma\bac\bcs\bs Use an emacs-style command line editing inter-
- face. This is enabled by default when the shell
+ e\bem\bma\bac\bcs\bs 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 -\b--\b-n\bno\boe\bed\bdi\bit\bti\bin\bng\bg option. This also affects the
+ the -\b--\b-n\bno\boe\bed\bdi\bit\bti\bin\bng\bg option. This also affects the
editing interface used for r\bre\bea\bad\bd -\b-e\be.
e\ber\brr\bre\bex\bxi\bit\bt Same as -\b-e\be.
e\ber\brr\brt\btr\bra\bac\bce\be
h\bhi\bis\bst\bte\bex\bxp\bpa\ban\bnd\bd
Same as -\b-H\bH.
h\bhi\bis\bst\bto\bor\bry\by Enable command history, as described above under
- H\bHI\bIS\bST\bTO\bOR\bRY\bY. This option is on by default in inter-
+ H\bHI\bIS\bST\bTO\bOR\bRY\bY. This option is on by default in inter-
active shells.
i\big\bgn\bno\bor\bre\bee\beo\bof\bf
- The effect is as if the shell command ``IG-
- NOREEOF=10'' had been executed (see S\bSh\bhe\bel\bll\bl V\bVa\bar\bri\bi-\b-
+ The effect is as if the shell command ``IG-
+ NOREEOF=10'' had been executed (see S\bSh\bhe\bel\bll\bl V\bVa\bar\bri\bi-\b-
a\bab\bbl\ble\bes\bs above).
k\bke\bey\byw\bwo\bor\brd\bd Same as -\b-k\bk.
m\bmo\bon\bni\bit\bto\bor\br Same as -\b-m\bm.
p\bph\bhy\bys\bsi\bic\bca\bal\bl
Same as -\b-P\bP.
p\bpi\bip\bpe\bef\bfa\bai\bil\bl
- 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.
- p\bpo\bos\bsi\bix\bx Change the behavior of b\bba\bas\bsh\bh where the default
- operation differs from the POSIX standard to
- match the standard (_\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be). See S\bSE\bEE\bE A\bAL\bLS\bSO\bO
+ p\bpo\bos\bsi\bix\bx Change the behavior of b\bba\bas\bsh\bh where the default
+ operation differs from the POSIX standard to
+ match the standard (_\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be). See S\bSE\bEE\bE A\bAL\bLS\bSO\bO
below for a reference to a document that details
how posix mode affects bash's behavior.
p\bpr\bri\biv\bvi\bil\ble\beg\bge\bed\bd
Same as -\b-p\bp.
v\bve\ber\brb\bbo\bos\bse\be Same as -\b-v\bv.
- v\bvi\bi Use a vi-style command line editing interface.
+ v\bvi\bi Use a vi-style command line editing interface.
This also affects the editing interface used for
r\bre\bea\bad\bd -\b-e\be.
x\bxt\btr\bra\bac\bce\be Same as -\b-x\bx.
- If -\b-o\bo is supplied with no _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints the
- current shell option settings. If +\b+o\bo is supplied with no
- _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints a series of s\bse\bet\bt commands to
- recreate the current option settings on the standard
+ If -\b-o\bo is supplied with no _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints the
+ current shell option settings. If +\b+o\bo is supplied with
+ no _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints a series of s\bse\bet\bt commands to
+ recreate the current option settings on the standard
output.
- -\b-p\bp Turn on _\bp_\br_\bi_\bv_\bi_\bl_\be_\bg_\be_\bd mode. In this mode, the $\b$E\bEN\bNV\bV and
- $\b$B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV files are not processed, shell functions are
- not inherited from the environment, and the S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS,
- B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS, C\bCD\bDP\bPA\bAT\bTH\bH, and G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE variables, if they ap-
- pear 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 -\b-p\bp option is not sup-
+ -\b-p\bp Turn on _\bp_\br_\bi_\bv_\bi_\bl_\be_\bg_\be_\bd mode. In this mode, the $\b$E\bEN\bNV\bV and
+ $\b$B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV files are not processed, shell functions are
+ not inherited from the environment, and the S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS,
+ B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS, C\bCD\bDP\bPA\bAT\bTH\bH, and G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE variables, if they ap-
+ pear 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 -\b-p\bp option is not sup-
plied, these actions are taken and the effective user id
- is set to the real user id. If the -\b-p\bp option is supplied
- at startup, the effective user id is not reset. Turning
- this option off causes the effective user and group ids
- to be set to the real user and group ids.
- -\b-r\br Enable restricted shell mode. This option cannot be un-
+ is set to the real user id. If the -\b-p\bp 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.
+ -\b-r\br Enable restricted shell mode. This option cannot be un-
set once it has been set.
-\b-t\bt Exit after reading and executing one command.
-\b-u\bu Treat unset variables and parameters other than the spe-
- cial parameters "@" and "*", or array variables sub-
- scripted with "@" or "*", as an error when performing
- parameter expansion. If expansion is attempted on an un-
- set variable or parameter, the shell prints an error
- message, and, if not interactive, exits with a non-zero
+ cial parameters "@" and "*", or array variables sub-
+ scripted with "@" or "*", 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.
-\b-v\bv Print shell input lines as they are read.
- -\b-x\bx After expanding each _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, f\bfo\bor\br command, c\bca\bas\bse\be
+ -\b-x\bx After expanding each _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, f\bfo\bor\br command, c\bca\bas\bse\be
command, s\bse\bel\ble\bec\bct\bt command, or arithmetic f\bfo\bor\br command, dis-
- play the expanded value of P\bPS\bS4\b4, followed by the command
- and its expanded arguments or associated word list, to
+ play the expanded value of P\bPS\bS4\b4, followed by the command
+ and its expanded arguments or associated word list, to
standard error.
- -\b-B\bB The shell performs brace expansion (see B\bBr\bra\bac\bce\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
- above). This is on by default.
- -\b-C\bC If set, b\bba\bas\bsh\bh does not overwrite an existing file with
- the >\b>, >\b>&\b&, and <\b<>\b> redirection operators. This may be
+ -\b-B\bB The shell performs brace expansion (see B\bBr\bra\bac\bce\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
+ above). This is on by default.
+ -\b-C\bC If set, b\bba\bas\bsh\bh does not overwrite an existing file with
+ the >\b>, >\b>&\b&, and <\b<>\b> redirection operators. This may be
overridden when creating output files by using the redi-
rection operator >\b>|\b| instead of >\b>.
-\b-E\bE If set, any trap on E\bER\bRR\bR is inherited by shell functions,
- command substitutions, and commands executed in a sub-
- shell environment. The E\bER\bRR\bR trap is normally not inher-
+ command substitutions, and commands executed in a sub-
+ shell environment. The E\bER\bRR\bR trap is normally not inher-
ited in such cases.
- -\b-H\bH Enable !\b! style history substitution. This option is on
+ -\b-H\bH Enable !\b! style history substitution. This option is on
by default when the shell is interactive.
- -\b-P\bP If set, the shell does not resolve symbolic links when
- executing commands such as c\bcd\bd that change the current
- working directory. It uses the physical directory struc-
- ture instead. By default, b\bba\bas\bsh\bh follows the logical chain
- of directories when performing commands which change the
- current directory.
- -\b-T\bT If set, any traps on D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN are inherited by
+ -\b-P\bP If set, the shell does not resolve symbolic links when
+ executing commands such as c\bcd\bd that change the current
+ working directory. It uses the physical directory
+ structure instead. By default, b\bba\bas\bsh\bh follows the logical
+ chain of directories when performing commands which
+ change the current directory.
+ -\b-T\bT If set, any traps on D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN are inherited by
shell functions, command substitutions, and commands ex-
- ecuted in a subshell environment. The D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN
+ ecuted in a subshell environment. The D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN
traps are normally not inherited in such cases.
- -\b--\b- If no arguments follow this option, then the positional
- parameters are unset. Otherwise, the positional parame-
- ters are set to the _\ba_\br_\bgs, even if some of them begin
+ -\b--\b- If no arguments follow this option, then the positional
+ parameters are unset. Otherwise, the positional parame-
+ ters are set to the _\ba_\br_\bgs, even if some of them begin
with a -\b-.
- -\b- Signal the end of options, cause all remaining _\ba_\br_\bgs to
- be assigned to the positional parameters. The -\b-x\bx and -\b-v\bv
- options are turned off. If there are no _\ba_\br_\bgs, the posi-
+ -\b- Signal the end of options, cause all remaining _\ba_\br_\bgs to
+ be assigned to the positional parameters. The -\b-x\bx and -\b-v\bv
+ options are turned off. If there are no _\ba_\br_\bgs, 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 $\b$-\b-. The return
- status is always true unless an invalid option is encountered.
+ The options are off by default unless otherwise noted. Using +
+ rather than - causes these options to be turned off. The op-
+ tions can also be specified as arguments to an invocation of the
+ shell. The current set of options may be found in $\b$-\b-. The re-
+ turn status is always true unless an invalid option is encoun-
+ tered.
s\bsh\bhi\bif\bft\bt [_\bn]
The positional parameters from _\bn+1 ... are renamed to $\b$1\b1 .\b..\b..\b..\b.
Parameters represented by the numbers $\b$#\b# down to $\b$#\b#-_\bn+1 are un-
- set. _\bn must be a non-negative number less than or equal to $\b$#\b#.
- If _\bn is 0, no parameters are changed. If _\bn is not given, it is
- assumed to be 1. If _\bn is greater than $\b$#\b#, the positional parame-
- ters are not changed. The return status is greater than zero if
- _\bn is greater than $\b$#\b# or less than zero; otherwise 0.
+ set. _\bn must be a non-negative number less than or equal to $\b$#\b#.
+ If _\bn is 0, no parameters are changed. If _\bn is not given, it is
+ assumed to be 1. If _\bn is greater than $\b$#\b#, the positional param-
+ eters are not changed. The return status is greater than zero
+ if _\bn is greater than $\b$#\b# or less than zero; otherwise 0.
s\bsh\bho\bop\bpt\bt [-\b-p\bpq\bqs\bsu\bu] [-\b-o\bo] [_\bo_\bp_\bt_\bn_\ba_\bm_\be ...]
Toggle the values of settings controlling optional shell behav-
- ior. The settings can be either those listed below, or, if the
+ ior. The settings can be either those listed below, or, if the
-\b-o\bo option is used, those available with the -\b-o\bo option to the s\bse\bet\bt
- builtin command. With no options, or with the -\b-p\bp option, a list
+ builtin command. With no options, or with the -\b-p\bp option, a list
of all settable options is displayed, with an indication of
whether or not each is set; if _\bo_\bp_\bt_\bn_\ba_\bm_\be_\bs are supplied, the output
- is restricted to those options. The -\b-p\bp option causes output to
- be displayed in a form that may be reused as input. Other op-
+ is restricted to those options. The -\b-p\bp option causes output to
+ be displayed in a form that may be reused as input. Other op-
tions have the following meanings:
-\b-s\bs Enable (set) each _\bo_\bp_\bt_\bn_\ba_\bm_\be.
-\b-u\bu Disable (unset) each _\bo_\bp_\bt_\bn_\ba_\bm_\be.
-\b-q\bq Suppresses normal output (quiet mode); the return status
- indicates whether the _\bo_\bp_\bt_\bn_\ba_\bm_\be is set or unset. If multi-
+ indicates whether the _\bo_\bp_\bt_\bn_\ba_\bm_\be is set or unset. If multi-
ple _\bo_\bp_\bt_\bn_\ba_\bm_\be arguments are given with -\b-q\bq, the return sta-
tus is zero if all _\bo_\bp_\bt_\bn_\ba_\bm_\be_\bs are enabled; non-zero other-
wise.
by default.
The return status when listing options is zero if all _\bo_\bp_\bt_\bn_\ba_\bm_\be_\bs
- are enabled, non-zero otherwise. When setting or unsetting op-
+ are enabled, non-zero otherwise. When setting or unsetting op-
tions, the return status is zero unless an _\bo_\bp_\bt_\bn_\ba_\bm_\be is not a
valid shell option.
Deprecated; a synonym for a\bar\brr\bra\bay\by_\b_e\bex\bxp\bpa\ban\bnd\bd_\b_o\bon\bnc\bce\be.
a\bau\but\bto\boc\bcd\bd If set, a command name that is the name of a directory
is executed as if it were the argument to the c\bcd\bd com-
- mand. This option is only used by interactive shells.
+ mand. This option is only used by interactive shells.
c\bcd\bda\bab\bbl\ble\be_\b_v\bva\bar\brs\bs
If set, an argument to the c\bcd\bd builtin command that is
not a directory is assumed to be the name of a variable
whose value is the directory to change to.
c\bcd\bds\bsp\bpe\bel\bll\bl If set, minor errors in the spelling of a directory com-
- ponent in a c\bcd\bd command will be corrected. The errors
+ ponent in a c\bcd\bd command will be corrected. The errors
checked for are transposed characters, a missing charac-
- ter, and one character too many. If a correction is
+ 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.
c\bch\bhe\bec\bck\bkh\bha\bas\bsh\bh
If set, b\bba\bas\bsh\bh checks that a command found in the hash ta-
- ble exists before trying to execute it. If a hashed com-
- mand 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.
c\bch\bhe\bec\bck\bkj\bjo\bob\bbs\bs
If set, b\bba\bas\bsh\bh lists the status of any stopped and running
jobs before exiting an interactive shell. If any jobs
are running, this causes the exit to be deferred until a
second exit is attempted without an intervening command
- (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL above). The shell always postpones ex-
+ (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL above). The shell always postpones ex-
iting if any jobs are stopped.
c\bch\bhe\bec\bck\bkw\bwi\bin\bns\bsi\biz\bze\be
If set, b\bba\bas\bsh\bh checks the window size after each external
(non-builtin) command and, if necessary, updates the
- values of L\bLI\bIN\bNE\bES\bS and C\bCO\bOL\bLU\bUM\bMN\bNS\bS. This option is enabled by
+ values of L\bLI\bIN\bNE\bES\bS and C\bCO\bOL\bLU\bUM\bMN\bNS\bS. This option is enabled by
default.
c\bcm\bmd\bdh\bhi\bis\bst\bt If set, b\bba\bas\bsh\bh attempts to save all lines of a multiple-
- line command in the same history entry. This allows easy
- re-editing of multi-line commands. This option is en-
- abled by default, but only has an effect if command his-
- tory is enabled, as described above under H\bHI\bIS\bST\bTO\bOR\bRY\bY.
+ line command in the same history entry. This allows
+ easy re-editing of multi-line commands. This option is
+ enabled by default, but only has an effect if command
+ history is enabled, as described above under H\bHI\bIS\bST\bTO\bOR\bRY\bY.
c\bco\bom\bmp\bpa\bat\bt3\b31\b1
c\bco\bom\bmp\bpa\bat\bt3\b32\b2
c\bco\bom\bmp\bpa\bat\bt4\b40\b0
c\bco\bom\bmp\bpl\ble\bet\bte\be_\b_f\bfu\bul\bll\blq\bqu\buo\bot\bte\be
If set, b\bba\bas\bsh\bh quotes all shell metacharacters in file-
- names and directory names when performing completion. If
- not set, b\bba\bas\bsh\bh removes metacharacters such as the dollar
- 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 backslashes to
- quote completed filenames. This variable is set by de-
- fault, which is the default bash behavior in versions
- through 4.2.
+ names and directory names when performing completion.
+ If not set, b\bba\bas\bsh\bh 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 ex-
+ pand 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.
d\bdi\bir\bre\bex\bxp\bpa\ban\bnd\bd
If set, b\bba\bas\bsh\bh replaces directory names with the results
of word expansion when performing filename completion.
This changes the contents of the readline editing buf-
- fer. If not set, b\bba\bas\bsh\bh attempts to preserve what the user
- typed.
+ fer. If not set, b\bba\bas\bsh\bh attempts to preserve what the
+ user typed.
d\bdi\bir\brs\bsp\bpe\bel\bll\bl
If set, b\bba\bas\bsh\bh attempts spelling correction on directory
tially supplied does not exist.
d\bdo\bot\btg\bgl\blo\bob\bb If set, b\bba\bas\bsh\bh includes filenames beginning with a `.' in
- the results of pathname expansion. The filenames `\b``\b`.\b.'\b''\b'
- and `\b``\b`.\b..\b.'\b''\b' must always be matched explicitly, even if
+ the results of pathname expansion. The filenames `\b``\b`.\b.'\b''\b'
+ and `\b``\b`.\b..\b.'\b''\b' must always be matched explicitly, even if
d\bdo\bot\btg\bgl\blo\bob\bb is set.
e\bex\bxe\bec\bcf\bfa\bai\bil\bl
If set, a non-interactive shell will not exit if it can-
not execute the file specified as an argument to the
- e\bex\bxe\bec\bc builtin command. An interactive shell does not exit
- if e\bex\bxe\bec\bc fails.
+ e\bex\bxe\bec\bc builtin command. An interactive shell does not
+ exit if e\bex\bxe\bec\bc fails.
e\bex\bxp\bpa\ban\bnd\bd_\b_a\bal\bli\bia\bas\bse\bes\bs
If set, aliases are expanded as described above under
e\bex\bxt\btd\bde\beb\bbu\bug\bg
If set at shell invocation, or in a shell startup file,
arrange to execute the debugger profile before the shell
- starts, identical to the -\b--\b-d\bde\beb\bbu\bug\bgg\bge\ber\br option. If set after
- invocation, behavior intended for use by debuggers is
- enabled:
+ starts, identical to the -\b--\b-d\bde\beb\bbu\bug\bgg\bge\ber\br option. If set af-
+ ter invocation, behavior intended for use by debuggers
+ is enabled:
1\b1.\b. The -\b-F\bF option to the d\bde\bec\bcl\bla\bar\bre\be builtin displays the
source file name and line number corresponding to
e\bex\bxt\btq\bqu\buo\bot\bte\be
If set, $\b$'_\bs_\bt_\br_\bi_\bn_\bg' and $\b$"_\bs_\bt_\br_\bi_\bn_\bg" quoting is performed
within $\b${\b{_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br}\b} expansions enclosed in double
- quotes. This option is enabled by default.
+ quotes. This option is enabled by default.
f\bfa\bai\bil\blg\bgl\blo\bob\bb
If set, patterns which fail to match filenames during
If set, the suffixes specified by the F\bFI\bIG\bGN\bNO\bOR\bRE\bE shell
variable cause words to be ignored when performing word
completion even if the ignored words are the only possi-
- ble completions. See S\bSH\bHE\bEL\bLL\bL V\bVA\bAR\bRI\bIA\bAB\bBL\bLE\bES\bS above for a de-
- scription of F\bFI\bIG\bGN\bNO\bOR\bRE\bE. This option is enabled by default.
+ ble completions. See S\bSH\bHE\bEL\bLL\bL V\bVA\bAR\bRI\bIA\bAB\bBL\bLE\bES\bS above for a de-
+ scription of F\bFI\bIG\bGN\bNO\bOR\bRE\bE. This option is enabled by de-
+ fault.
g\bgl\blo\bob\bba\bas\bsc\bci\bii\bir\bra\ban\bng\bge\bes\bs
- If set, range expressions used in pattern matching
- bracket expressions (see P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg above) behave
- as if in the traditional C locale when performing com-
- parisons. That is, the current locale's collating se-
- quence is not taken into account, so b\bb will not collate
- between A\bA and B\bB, and upper-case and lower-case ASCII
+ If set, range expressions used in pattern matching
+ bracket expressions (see P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg above) behave
+ as if in the traditional C locale when performing com-
+ parisons. That is, the current locale's collating se-
+ quence is not taken into account, so b\bb will not collate
+ between A\bA and B\bB, and upper-case and lower-case ASCII
characters will collate together.
g\bgl\blo\bob\bbs\bsk\bki\bip\bpd\bdo\bot\bts\bs
- If set, pathname expansion will never match the file-
- names `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b', even if the pattern begins with
- a `\b``\b`.\b.'\b''\b'. This option is enabled by default.
+ If set, pathname expansion will never match the file-
+ names `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b', even if the pattern begins with
+ a `\b``\b`.\b.'\b''\b'. This option is enabled by default.
g\bgl\blo\bob\bbs\bst\bta\bar\br
If set, the pattern *\b**\b* 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 /\b/,
+ text will match all files and zero or more directories
+ and subdirectories. If the pattern is followed by a /\b/,
only directories and subdirectories match.
g\bgn\bnu\bu_\b_e\ber\brr\brf\bfm\bmt\bt
GNU error message format.
h\bhi\bis\bst\bta\bap\bpp\bpe\ben\bnd\bd
- If set, the history list is appended to the file named
+ If set, the history list is appended to the file named
by the value of the H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE variable when the shell ex-
its, rather than overwriting the file.
h\bhi\bis\bst\btr\bre\bee\bed\bdi\bit\bt
- If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, a user is given the
+ If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, a user is given the
opportunity to re-edit a failed history substitution.
h\bhi\bis\bst\btv\bve\ber\bri\bif\bfy\by
- If set, and r\bre\bea\bad\bdl\bli\bin\bne\be 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 r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer, allowing further modifica-
- tion.
+ If set, and r\bre\bea\bad\bdl\bli\bin\bne\be 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 r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer, allowing further modi-
+ fication.
h\bho\bos\bst\btc\bco\bom\bmp\bpl\ble\bet\bte\be
If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, b\bba\bas\bsh\bh will attempt to
- perform hostname completion when a word containing a @\b@
- is being completed (see C\bCo\bom\bmp\bpl\ble\bet\bti\bin\bng\bg under R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE
- above). This is enabled by default.
+ perform hostname completion when a word containing a @\b@
+ is being completed (see C\bCo\bom\bmp\bpl\ble\bet\bti\bin\bng\bg under R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE
+ above). This is enabled by default.
h\bhu\bup\bpo\bon\bne\bex\bxi\bit\bt
If set, b\bba\bas\bsh\bh will send S\bSI\bIG\bGH\bHU\bUP\bP to all jobs when an inter-
active login shell exits.
i\bin\bnh\bhe\ber\bri\bit\bt_\b_e\ber\brr\bre\bex\bxi\bit\bt
- If set, command substitution inherits the value of the
- e\ber\brr\bre\bex\bxi\bit\bt option, instead of unsetting it in the subshell
- environment. This option is enabled when _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be is
+ If set, command substitution inherits the value of the
+ e\ber\brr\bre\bex\bxi\bit\bt option, instead of unsetting it in the subshell
+ environment. This option is enabled when _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be is
enabled.
i\bin\bnt\bte\ber\bra\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs
If set, allow a word beginning with #\b# to cause that word
- and all remaining characters on that line to be ignored
- in an interactive shell (see C\bCO\bOM\bMM\bME\bEN\bNT\bTS\bS above). This op-
+ and all remaining characters on that line to be ignored
+ in an interactive shell (see C\bCO\bOM\bMM\bME\bEN\bNT\bTS\bS above). This op-
tion is enabled by default.
l\bla\bas\bst\btp\bpi\bip\bpe\be
- 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.
- l\bli\bit\bth\bhi\bis\bst\bt If set, and the c\bcm\bmd\bdh\bhi\bis\bst\bt option is enabled, multi-line
+ l\bli\bit\bth\bhi\bis\bst\bt If set, and the c\bcm\bmd\bdh\bhi\bis\bst\bt option is enabled, multi-line
commands are saved to the history with embedded newlines
rather than using semicolon separators where possible.
l\blo\boc\bca\bal\blv\bva\bar\br_\b_i\bin\bnh\bhe\ber\bri\bit\bt
If set, local variables inherit the value and attributes
of a variable of the same name that exists at a previous
- scope before any new value is assigned. The nameref at-
+ scope before any new value is assigned. The nameref at-
tribute is not inherited.
l\blo\boc\bca\bal\blv\bva\bar\br_\b_u\bun\bns\bse\bet\bt
- If set, calling u\bun\bns\bse\bet\bt on local variables in previous
- function scopes marks them so subsequent lookups find
- them unset until that function returns. This is identi-
- cal to the behavior of unsetting local variables at the
+ If set, calling u\bun\bns\bse\bet\bt on local variables in previous
+ function scopes marks them so subsequent lookups find
+ them unset until that function returns. This is identi-
+ cal to the behavior of unsetting local variables at the
current function scope.
l\blo\bog\bgi\bin\bn_\b_s\bsh\bhe\bel\bll\bl
- The shell sets this option if it is started as a login
- shell (see I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN above). The value may not be
+ The shell sets this option if it is started as a login
+ shell (see I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN above). The value may not be
changed.
m\bma\bai\bil\blw\bwa\bar\brn\bn
- If set, and a file that b\bba\bas\bsh\bh is checking for mail has
- been accessed since the last time it was checked, the
- message ``The mail in _\bm_\ba_\bi_\bl_\bf_\bi_\bl_\be has been read'' is dis-
+ If set, and a file that b\bba\bas\bsh\bh is checking for mail has
+ been accessed since the last time it was checked, the
+ message ``The mail in _\bm_\ba_\bi_\bl_\bf_\bi_\bl_\be has been read'' is dis-
played.
n\bno\bo_\b_e\bem\bmp\bpt\bty\by_\b_c\bcm\bmd\bd_\b_c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bn
- If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, b\bba\bas\bsh\bh will not at-
- tempt to search the P\bPA\bAT\bTH\bH for possible completions when
+ If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, b\bba\bas\bsh\bh will not at-
+ tempt to search the P\bPA\bAT\bTH\bH for possible completions when
completion is attempted on an empty line.
n\bno\boc\bca\bas\bse\beg\bgl\blo\bob\bb
- If set, b\bba\bas\bsh\bh matches filenames in a case-insensitive
+ If set, b\bba\bas\bsh\bh matches filenames in a case-insensitive
fashion when performing pathname expansion (see P\bPa\bat\bth\bhn\bna\bam\bme\be
E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn above).
n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh
- If set, b\bba\bas\bsh\bh matches patterns in a case-insensitive
+ If set, b\bba\bas\bsh\bh matches patterns in a case-insensitive
fashion when performing matching while executing c\bca\bas\bse\be or
[\b[[\b[ conditional commands, when performing pattern substi-
- tution word expansions, or when filtering possible com-
+ tution word expansions, or when filtering possible com-
pletions as part of programmable completion.
n\bno\boe\bex\bxp\bpa\ban\bnd\bd_\b_t\btr\bra\ban\bns\bsl\bla\bat\bti\bio\bon\bn
- If set, b\bba\bas\bsh\bh encloses the translated results of $"..."
- quoting in single quotes instead of double quotes. If
+ If set, b\bba\bas\bsh\bh encloses the translated results of $"..."
+ quoting in single quotes instead of double quotes. If
the string is not translated, this has no effect.
n\bnu\bul\bll\blg\bgl\blo\bob\bb
- If set, b\bba\bas\bsh\bh allows patterns which match no files (see
- P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn above) to expand to a null string,
+ If set, b\bba\bas\bsh\bh allows patterns which match no files (see
+ P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn above) to expand to a null string,
rather than themselves.
p\bpa\bat\bts\bsu\bub\bb_\b_r\bre\bep\bpl\bla\bac\bce\bem\bme\ben\bnt\bt
If set, b\bba\bas\bsh\bh expands occurrences of &\b& in the replacement
- string of pattern substitution to the text matched by
- the pattern, as described under P\bPa\bar\bra\bam\bme\bet\bte\ber\br E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
- above. This option is enabled by default.
+ string of pattern substitution to the text matched by
+ the pattern, as described under P\bPa\bar\bra\bam\bme\bet\bte\ber\br E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
+ above. This option is enabled by default.
p\bpr\bro\bog\bgc\bco\bom\bmp\bp
If set, the programmable completion facilities (see P\bPr\bro\bo-\b-
- g\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn above) are enabled. This option is
+ g\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn above) are enabled. This option is
enabled by default.
p\bpr\bro\bog\bgc\bco\bom\bmp\bp_\b_a\bal\bli\bia\bas\bs
- If set, and programmable completion is enabled, b\bba\bas\bsh\bh
- treats a command name that doesn't have any completions
- as a possible alias and attempts alias expansion. If it
- has an alias, b\bba\bas\bsh\bh attempts programmable completion us-
+ If set, and programmable completion is enabled, b\bba\bas\bsh\bh
+ treats a command name that doesn't have any completions
+ as a possible alias and attempts alias expansion. If it
+ has an alias, b\bba\bas\bsh\bh attempts programmable completion us-
ing the command word resulting from the expanded alias.
p\bpr\bro\bom\bmp\bpt\btv\bva\bar\brs\bs
If set, prompt strings undergo parameter expansion, com-
- mand substitution, arithmetic expansion, and quote re-
- moval after being expanded as described in P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG
- above. This option is enabled by default.
+ mand substitution, arithmetic expansion, and quote re-
+ moval after being expanded as described in P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG
+ above. This option is enabled by default.
r\bre\bes\bst\btr\bri\bic\bct\bte\bed\bd_\b_s\bsh\bhe\bel\bll\bl
- The shell sets this option if it is started in re-
- stricted mode (see R\bRE\bES\bST\bTR\bRI\bIC\bCT\bTE\bED\bD S\bSH\bHE\bEL\bLL\bL below). The value
- may not be changed. This is not reset when the startup
- files are executed, allowing the startup files to dis-
+ The shell sets this option if it is started in re-
+ stricted mode (see R\bRE\bES\bST\bTR\bRI\bIC\bCT\bTE\bED\bD S\bSH\bHE\bEL\bLL\bL below). The value
+ 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.
s\bsh\bhi\bif\bft\bt_\b_v\bve\ber\brb\bbo\bos\bse\be
- If set, the s\bsh\bhi\bif\bft\bt builtin prints an error message when
+ If set, the s\bsh\bhi\bif\bft\bt builtin prints an error message when
the shift count exceeds the number of positional parame-
ters.
s\bso\bou\bur\brc\bce\bep\bpa\bat\bth\bh
If set, the .\b. (s\bso\bou\bur\brc\bce\be) builtin uses the value of P\bPA\bAT\bTH\bH to
- find the directory containing the file supplied as an
- argument. This option is enabled by default.
+ find the directory containing the file supplied as an
+ argument. This option is enabled by default.
v\bva\bar\brr\bre\bed\bdi\bir\br_\b_c\bcl\blo\bos\bse\be
- If set, the shell automatically closes file descriptors
+ If set, the shell automatically closes file descriptors
assigned using the _\b{_\bv_\ba_\br_\bn_\ba_\bm_\be_\b} redirection syntax (see R\bRE\bE-\b-
- D\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN above) instead of leaving them open when the
+ D\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN above) instead of leaving them open when the
command completes.
x\bxp\bpg\bg_\b_e\bec\bch\bho\bo
- If set, the e\bec\bch\bho\bo builtin expands backslash-escape se-
- quences by default. If the p\bpo\bos\bsi\bix\bx shell option is also
+ If set, the e\bec\bch\bho\bo builtin expands backslash-escape se-
+ quences by default. If the p\bpo\bos\bsi\bix\bx shell option is also
enabled, e\bec\bch\bho\bo does not interpret any options.
s\bsu\bus\bsp\bpe\ben\bnd\bd [-\b-f\bf]
- Suspend the execution of this shell until it receives a S\bSI\bIG\bGC\bCO\bON\bNT\bT
- signal. A login shell, or a shell without job control enabled,
- cannot be suspended; the -\b-f\bf option can be used to override this
- and force the suspension. The return status is 0 unless the
- shell is a login shell or job control is not enabled and -\b-f\bf is
+ Suspend the execution of this shell until it receives a S\bSI\bIG\bGC\bCO\bON\bNT\bT
+ signal. A login shell, or a shell without job control enabled,
+ cannot be suspended; the -\b-f\bf option can be used to override this
+ and force the suspension. The return status is 0 unless the
+ shell is a login shell or job control is not enabled and -\b-f\bf is
not supplied.
t\bte\bes\bst\bt _\be_\bx_\bp_\br
[\b[ _\be_\bx_\bp_\br ]\b]
Return a status of 0 (true) or 1 (false) depending on the evalu-
- ation of the conditional expression _\be_\bx_\bp_\br. Each operator and op-
- erand must be a separate argument. Expressions are composed of
- the primaries described above under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS.
- t\bte\bes\bst\bt does not accept any options, nor does it accept and ignore
+ ation of the conditional expression _\be_\bx_\bp_\br. Each operator and op-
+ erand must be a separate argument. Expressions are composed of
+ the primaries described above under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS.
+ t\bte\bes\bst\bt does not accept any options, nor does it accept and ignore
an argument of -\b--\b- as signifying the end of options.
- 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 precedence is
- used when there are five or more arguments.
+ Expressions may be combined using the following operators,
+ listed in decreasing order of precedence. The evaluation de-
+ pends on the number of arguments; see below. Operator prece-
+ dence is used when there are five or more arguments.
!\b! _\be_\bx_\bp_\br True if _\be_\bx_\bp_\br is false.
(\b( _\be_\bx_\bp_\br )\b)
- Returns the value of _\be_\bx_\bp_\br. This may be used to override
+ Returns the value of _\be_\bx_\bp_\br. This may be used to override
the normal precedence of operators.
_\be_\bx_\bp_\br_\b1 -a\ba _\be_\bx_\bp_\br_\b2
True if both _\be_\bx_\bp_\br_\b1 and _\be_\bx_\bp_\br_\b2 are true.
null.
2 arguments
If the first argument is !\b!, 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 C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS, the expression is
- true if the unary test is true. If the first argument is
+ only if the second argument is null. If the first argu-
+ ment is one of the unary conditional operators listed
+ above under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS, 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 C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS, the
result of the expression is the result of the binary test
- using the first and third arguments as operands. The -\b-a\ba
- and -\b-o\bo operators are considered binary operators when
- there are three arguments. If the first argument is !\b!,
- the value is the negation of the two-argument test using
- the second and third arguments. If the first argument is
+ using the first and third arguments as operands. The -\b-a\ba
+ and -\b-o\bo operators are considered binary operators when
+ there are three arguments. If the first argument is !\b!,
+ the value is the negation of the two-argument test using
+ the second and third arguments. If the first argument is
exactly (\b( and the third argument is exactly )\b), 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
The following conditions are applied in the order listed.
If the first argument is !\b!, the result is the negation of
- the three-argument expression composed of the remaining
- arguments. the two-argument test using the second and
- third arguments. If the first argument is exactly (\b( and
- the fourth argument is exactly )\b), the result is the two-
- argument test of the second and third arguments. Other-
+ the three-argument expression composed of the remaining
+ arguments. the two-argument test using the second and
+ third arguments. If the first argument is exactly (\b( and
+ the fourth argument is exactly )\b), the result is the two-
+ argument test of the second and third arguments. Other-
wise, the expression is parsed and evaluated 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.
If the shell is not in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, when used with t\bte\bes\bst\bt or [\b[, the
- <\b< and >\b> operators sort lexicographically using ASCII ordering.
- When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, these operators sort using the
+ <\b< and >\b> operators sort lexicographically using ASCII ordering.
+ When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, these operators sort using the
current locale.
- t\bti\bim\bme\bes\bs Print the accumulated user and system times for the shell and
- for processes run from the shell. The return status is 0.
+ t\bti\bim\bme\bes\bs Print the accumulated user and system times for the shell and
+ for processes run from the shell. The return status is 0.
t\btr\bra\bap\bp [-\b-l\blp\bp] [[_\ba_\bc_\bt_\bi_\bo_\bn] _\bs_\bi_\bg_\bs_\bp_\be_\bc ...]
The _\ba_\bc_\bt_\bi_\bo_\bn is a command that is read and executed when the shell
- receives signal(s) _\bs_\bi_\bg_\bs_\bp_\be_\bc. If _\ba_\bc_\bt_\bi_\bo_\bn is absent (and there is a
- single _\bs_\bi_\bg_\bs_\bp_\be_\bc) or -\b-, each specified signal is reset to its
- original disposition (the value it had upon entrance to the
- shell). If _\ba_\bc_\bt_\bi_\bo_\bn is the null string the signal specified by
- each _\bs_\bi_\bg_\bs_\bp_\be_\bc is ignored by the shell and by the commands it in-
+ receives signal(s) _\bs_\bi_\bg_\bs_\bp_\be_\bc. If _\ba_\bc_\bt_\bi_\bo_\bn is absent (and there is a
+ single _\bs_\bi_\bg_\bs_\bp_\be_\bc) or -\b-, each specified signal is reset to its
+ original disposition (the value it had upon entrance to the
+ shell). If _\ba_\bc_\bt_\bi_\bo_\bn is the null string the signal specified by
+ each _\bs_\bi_\bg_\bs_\bp_\be_\bc is ignored by the shell and by the commands it in-
vokes.
- If no arguments are supplied, t\btr\bra\bap\bp displays the actions associ-
+ If no arguments are supplied, t\btr\bra\bap\bp displays the actions associ-
ated with each trapped signal as a set of t\btr\bra\bap\bp commands that can
- be reused as shell input to restore the current signal disposi-
- tions. If -\b-p\bp is given, and _\ba_\bc_\bt_\bi_\bo_\bn is not present, then t\btr\bra\bap\bp dis-
- plays the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc or, if none are
- supplied, for all trapped signals, as a set of t\btr\bra\bap\bp commands
- that can be reused as shell input to restore the current signal
- dispositions. The -\b-P\bP option behaves similarly, but displays only
- the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. -\b-P\bP requires
- at least one _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. The -\b-P\bP or -\b-p\bp options to t\btr\bra\bap\bp may
- be used in a subshell environment (e.g., command substitution)
- and, as long as they are used before t\btr\bra\bap\bp is used to change a
- signal's handling, will display the state of its parent's traps.
+ be reused as shell input to restore the current signal disposi-
+ tions. If -\b-p\bp is given, and _\ba_\bc_\bt_\bi_\bo_\bn is not present, then t\btr\bra\bap\bp
+ displays the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc or, if none
+ are supplied, for all trapped signals, as a set of t\btr\bra\bap\bp commands
+ that can be reused as shell input to restore the current signal
+ dispositions. The -\b-P\bP option behaves similarly, but displays
+ only the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. -\b-P\bP re-
+ quires at least one _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. The -\b-P\bP or -\b-p\bp options to
+ t\btr\bra\bap\bp may be used in a subshell environment (e.g., command sub-
+ stitution) and, as long as they are used before t\btr\bra\bap\bp is used to
+ change a signal's handling, will display the state of its par-
+ ent's traps.
The -\b-l\bl option causes t\btr\bra\bap\bp to print a list of signal names and
- their corresponding numbers. Each _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a signal
- name defined in <_\bs_\bi_\bg_\bn_\ba_\bl_\b._\bh>, or a signal number. Signal names are
- case insensitive and the S\bSI\bIG\bG prefix is optional.
+ their corresponding numbers. Each _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a signal
+ name defined in <_\bs_\bi_\bg_\bn_\ba_\bl_\b._\bh>, or a signal number. Signal names
+ are case insensitive and the S\bSI\bIG\bG prefix is optional.
If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is E\bEX\bXI\bIT\bT (0) the command _\ba_\bc_\bt_\bi_\bo_\bn is executed on exit
- from the shell. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is D\bDE\bEB\bBU\bUG\bG, the command _\ba_\bc_\bt_\bi_\bo_\bn is ex-
- ecuted before every _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, _\bf_\bo_\br command, _\bc_\ba_\bs_\be command,
+ from the shell. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is D\bDE\bEB\bBU\bUG\bG, the command _\ba_\bc_\bt_\bi_\bo_\bn is
+ executed before every _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, _\bf_\bo_\br command, _\bc_\ba_\bs_\be command,
_\bs_\be_\bl_\be_\bc_\bt command, (( arithmetic command, [[ conditional command,
arithmetic _\bf_\bo_\br command, and before the first command executes in
- a shell function (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR above). Refer to the de-
+ a shell function (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR above). Refer to the de-
scription of the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the s\bsh\bho\bop\bpt\bt builtin for de-
- tails of its effect on the D\bDE\bEB\bBU\bUG\bG trap. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is R\bRE\bET\bTU\bUR\bRN\bN,
+ tails of its effect on the D\bDE\bEB\bBU\bUG\bG trap. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is R\bRE\bET\bTU\bUR\bRN\bN,
the command _\ba_\bc_\bt_\bi_\bo_\bn is executed each time a shell function or a
script executed with the .\b. or s\bso\bou\bur\brc\bce\be builtins finishes execut-
ing.
tion.
When the shell is not interactive, signals ignored upon entry to
- the shell cannot be trapped or reset. Interactive shells permit
- trapping signals ignored on entry. Trapped signals that are not
+ the shell cannot be trapped or reset. Interactive shells permit
+ trapping signals ignored on entry. 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
+ or subshell environment when one is created. The return status
is false if any _\bs_\bi_\bg_\bs_\bp_\be_\bc is invalid; otherwise t\btr\bra\bap\bp returns true.
t\btr\bru\bue\be Does nothing, returns a 0 status.
t\bty\byp\bpe\be [-\b-a\baf\bft\btp\bpP\bP] _\bn_\ba_\bm_\be [_\bn_\ba_\bm_\be ...]
With no options, indicate how each _\bn_\ba_\bm_\be would be interpreted if
- used as a command name. If the -\b-t\bt option is used, t\bty\byp\bpe\be prints a
+ used as a command name. If the -\b-t\bt option is used, t\bty\byp\bpe\be prints a
string which is one of _\ba_\bl_\bi_\ba_\bs, _\bk_\be_\by_\bw_\bo_\br_\bd, _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn, _\bb_\bu_\bi_\bl_\bt_\bi_\bn, or
_\bf_\bi_\bl_\be if _\bn_\ba_\bm_\be is an alias, shell reserved word, function,
- builtin, or executable disk file, respectively. If the _\bn_\ba_\bm_\be is
+ builtin, or executable disk file, respectively. If the _\bn_\ba_\bm_\be is
not found, then nothing is printed, and t\bty\byp\bpe\be returns a non-zero
exit status. If the -\b-p\bp option is used, t\bty\byp\bpe\be either returns the
name of the executable file that would be found by searching
$\b$P\bPA\bAT\bTH\bH if _\bn_\ba_\bm_\be were specified as a command name, or nothing if
- ``type -t name'' would not return _\bf_\bi_\bl_\be. The -\b-P\bP option forces a
+ ``type -t name'' would not return _\bf_\bi_\bl_\be. The -\b-P\bP option forces a
P\bPA\bAT\bTH\bH search for each _\bn_\ba_\bm_\be, even if ``type -t name'' would not
- return _\bf_\bi_\bl_\be. If a command is hashed, -\b-p\bp and -\b-P\bP print the hashed
+ return _\bf_\bi_\bl_\be. If a command is hashed, -\b-p\bp and -\b-P\bP print the hashed
value, which is not necessarily the file that appears first in
- P\bPA\bAT\bTH\bH. If the -\b-a\ba option is used, t\bty\byp\bpe\be prints all of the places
- that contain a command named _\bn_\ba_\bm_\be. This includes aliases, re-
+ P\bPA\bAT\bTH\bH. If the -\b-a\ba option is used, t\bty\byp\bpe\be prints all of the places
+ that contain a command named _\bn_\ba_\bm_\be. This includes aliases, re-
served words, functions, and builtins, but the path search op-
tions (-\b-p\bp and -\b-P\bP) can be supplied to restrict the output to exe-
- cutable files. t\bty\byp\bpe\be does not consult the table of hashed com-
+ cutable files. t\bty\byp\bpe\be does not consult the table of hashed com-
mands when using -\b-a\ba with -\b-p\bp, and only performs a P\bPA\bAT\bTH\bH search for
- _\bn_\ba_\bm_\be. The -\b-f\bf option suppresses shell function lookup, as with
- the c\bco\bom\bmm\bma\ban\bnd\bd builtin. t\bty\byp\bpe\be returns true if all of the arguments
+ _\bn_\ba_\bm_\be. The -\b-f\bf option suppresses shell function lookup, as with
+ the c\bco\bom\bmm\bma\ban\bnd\bd builtin. t\bty\byp\bpe\be returns true if all of the arguments
are found, false if any are not found.
u\bul\bli\bim\bmi\bit\bt [-\b-H\bHS\bS] -\b-a\ba
Provides control over the resources available to the shell and
to processes started by it, on systems that allow such control.
The -\b-H\bH and -\b-S\bS options specify that the hard or soft limit is set
- for the given resource. A hard limit cannot be increased by a
+ 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 -\b-H\bH nor -\b-S\bS is speci-
- fied, both the soft and hard limits are set. The value of _\bl_\bi_\bm_\bi_\bt
+ to the value of the hard limit. If neither -\b-H\bH nor -\b-S\bS is speci-
+ fied, both the soft and hard limits are set. The value of _\bl_\bi_\bm_\bi_\bt
can be a number in the unit specified for the resource or one of
the special values h\bha\bar\brd\bd, s\bso\bof\bft\bt, or u\bun\bnl\bli\bim\bmi\bit\bte\bed\bd, which stand for the
current hard limit, the current soft limit, and no limit, re-
- spectively. If _\bl_\bi_\bm_\bi_\bt is omitted, the current value of the soft
+ spectively. If _\bl_\bi_\bm_\bi_\bt is omitted, the current value of the soft
limit of the resource is printed, unless the -\b-H\bH option is given.
When more than one resource is specified, the limit name and
- unit, if appropriate, are printed before the value. Other op-
+ unit, if appropriate, are printed before the value. Other op-
tions are interpreted as follows:
-\b-a\ba All current limits are reported; no limits are set
-\b-b\bb The maximum socket buffer size
-\b-T\bT The maximum number of threads
If _\bl_\bi_\bm_\bi_\bt is given, and the -\b-a\ba option is not used, _\bl_\bi_\bm_\bi_\bt is the
- new value of the specified resource. If no option is given, then
- -\b-f\bf is assumed. Values are in 1024-byte increments, except for
- -\b-t\bt, which is in seconds; -\b-R\bR, which is in microseconds; -\b-p\bp, which
- is in units of 512-byte blocks; -\b-P\bP, -\b-T\bT, -\b-b\bb, -\b-k\bk, -\b-n\bn, and -\b-u\bu,
- which are unscaled values; and, when in posix mode, -\b-c\bc and -\b-f\bf,
- which are in 512-byte increments. The return status is 0 unless
- an invalid option or argument is supplied, or an error occurs
- while setting a new limit.
+ new value of the specified resource. If no option is given,
+ then -\b-f\bf is assumed. Values are in 1024-byte increments, except
+ for -\b-t\bt, which is in seconds; -\b-R\bR, which is in microseconds; -\b-p\bp,
+ which is in units of 512-byte blocks; -\b-P\bP, -\b-T\bT, -\b-b\bb, -\b-k\bk, -\b-n\bn, and
+ -\b-u\bu, which are unscaled values; and, when in posix mode, -\b-c\bc and
+ -\b-f\bf, which are in 512-byte increments. The return status is 0
+ unless an invalid option or argument is supplied, or an error
+ occurs while setting a new limit.
u\bum\bma\bas\bsk\bk [-\b-p\bp] [-\b-S\bS] [_\bm_\bo_\bd_\be]
- The user file-creation mask is set to _\bm_\bo_\bd_\be. If _\bm_\bo_\bd_\be begins with
+ The user file-creation mask is set to _\bm_\bo_\bd_\be. If _\bm_\bo_\bd_\be 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
- _\bc_\bh_\bm_\bo_\bd(1). If _\bm_\bo_\bd_\be is omitted, the current value of the mask is
- printed. The -\b-S\bS option causes the mask to be printed in symbolic
- form; the default output is an octal number. If the -\b-p\bp option is
- supplied, and _\bm_\bo_\bd_\be is omitted, the output is in a form that may
- be reused as input. The return status is 0 if the mode was suc-
- cessfully changed or if no _\bm_\bo_\bd_\be argument was supplied, and false
- otherwise.
+ _\bc_\bh_\bm_\bo_\bd(1). If _\bm_\bo_\bd_\be is omitted, the current value of the mask is
+ printed. The -\b-S\bS option causes the mask to be printed in sym-
+ bolic form; the default output is an octal number. If the -\b-p\bp
+ option is supplied, and _\bm_\bo_\bd_\be 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 _\bm_\bo_\bd_\be argument was supplied,
+ and false otherwise.
u\bun\bna\bal\bli\bia\bas\bs [-a\ba] [_\bn_\ba_\bm_\be ...]
- Remove each _\bn_\ba_\bm_\be from the list of defined aliases. If -\b-a\ba is sup-
- plied, all alias definitions are removed. The return value is
- true unless a supplied _\bn_\ba_\bm_\be is not a defined alias.
+ Remove each _\bn_\ba_\bm_\be from the list of defined aliases. If -\b-a\ba is
+ supplied, all alias definitions are removed. The return value
+ is true unless a supplied _\bn_\ba_\bm_\be is not a defined alias.
u\bun\bns\bse\bet\bt [-f\bfv\bv] [-n\bn] [_\bn_\ba_\bm_\be ...]
- For each _\bn_\ba_\bm_\be, remove the corresponding variable or function. If
- the -\b-v\bv option is given, each _\bn_\ba_\bm_\be refers to a shell variable,
- and that variable is removed. Read-only variables may not be un-
- set. If -\b-f\bf is specified, each _\bn_\ba_\bm_\be refers to a shell function,
- and the function definition is removed. If the -\b-n\bn option is sup-
- plied, and _\bn_\ba_\bm_\be is a variable with the _\bn_\ba_\bm_\be_\br_\be_\bf attribute, _\bn_\ba_\bm_\be
- will be unset rather than the variable it references. -\b-n\bn has no
- effect if the -\b-f\bf option is supplied. If no options are supplied,
- each _\bn_\ba_\bm_\be refers to a variable; if there is no variable by that
- name, a function with that name, if any, is unset. Each unset
- variable or function is removed from the environment passed to
- subsequent commands. If any of B\bBA\bAS\bSH\bH_\b_A\bAL\bLI\bIA\bAS\bSE\bES\bS, B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0,
- B\bBA\bAS\bSH\bH_\b_C\bCM\bMD\bDS\bS, B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD, B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL, B\bBA\bAS\bSH\bHP\bPI\bID\bD, C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bD-\b-
- B\bBR\bRE\bEA\bAK\bKS\bS, D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK, E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE, E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS, F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE, G\bGR\bRO\bOU\bUP\bPS\bS,
- H\bHI\bIS\bST\bTC\bCM\bMD\bD, L\bLI\bIN\bNE\bEN\bNO\bO, R\bRA\bAN\bND\bDO\bOM\bM, S\bSE\bEC\bCO\bON\bND\bDS\bS, or S\bSR\bRA\bAN\bND\bDO\bOM\bM are unset, they
- lose their special properties, even if they are subsequently re-
- set. The exit status is true unless a _\bn_\ba_\bm_\be is readonly or may
- not be unset.
+ For each _\bn_\ba_\bm_\be, remove the corresponding variable or function.
+ If the -\b-v\bv option is given, each _\bn_\ba_\bm_\be refers to a shell variable,
+ and that variable is removed. Read-only variables may not be
+ unset. If -\b-f\bf is specified, each _\bn_\ba_\bm_\be refers to a shell func-
+ tion, and the function definition is removed. If the -\b-n\bn option
+ is supplied, and _\bn_\ba_\bm_\be is a variable with the _\bn_\ba_\bm_\be_\br_\be_\bf attribute,
+ _\bn_\ba_\bm_\be will be unset rather than the variable it references. -\b-n\bn
+ has no effect if the -\b-f\bf option is supplied. If no options are
+ supplied, each _\bn_\ba_\bm_\be refers to a variable; if there is no vari-
+ able by that name, a function with that name, if any, is unset.
+ Each unset variable or function is removed from the environment
+ passed to subsequent commands. If any of B\bBA\bAS\bSH\bH_\b_A\bAL\bLI\bIA\bAS\bSE\bES\bS,
+ B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0, B\bBA\bAS\bSH\bH_\b_C\bCM\bMD\bDS\bS, B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD, B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL, B\bBA\bAS\bSH\bHP\bPI\bID\bD,
+ C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS, D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK, E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE, E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS, F\bFU\bUN\bNC\bC-\b-
+ N\bNA\bAM\bME\bE, G\bGR\bRO\bOU\bUP\bPS\bS, H\bHI\bIS\bST\bTC\bCM\bMD\bD, L\bLI\bIN\bNE\bEN\bNO\bO, R\bRA\bAN\bND\bDO\bOM\bM, S\bSE\bEC\bCO\bON\bND\bDS\bS, or S\bSR\bRA\bAN\bND\bDO\bOM\bM are
+ unset, they lose their special properties, even if they are sub-
+ sequently reset. The exit status is true unless a _\bn_\ba_\bm_\be is read-
+ only or may not be unset.
w\bwa\bai\bit\bt [-\b-f\bfn\bn] [-\b-p\bp _\bv_\ba_\br_\bn_\ba_\bm_\be] [_\bi_\bd _\b._\b._\b.]
Wait for each specified child process and return its termination
- status. Each _\bi_\bd 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 _\bi_\bd is not given, w\bwa\bai\bit\bt waits for all running back-
- ground jobs and the last-executed process substitution, if its
- process id is the same as $\b$!\b!, and the return status is zero. If
- the -\b-n\bn option is supplied, w\bwa\bai\bit\bt waits for a single job from the
- list of _\bi_\bds or, if no _\bi_\bds are supplied, any job, to complete and
- returns its exit status. If none of the supplied arguments is a
- child of the shell, or if no arguments are supplied and the
- shell has no unwaited-for children, the exit status is 127. If
+ status. Each _\bi_\bd 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 _\bi_\bd is not given, w\bwa\bai\bit\bt waits for all running
+ background jobs and the last-executed process substitution, if
+ its process id is the same as $\b$!\b!, and the return status is zero.
+ If the -\b-n\bn option is supplied, w\bwa\bai\bit\bt waits for a single job from
+ the list of _\bi_\bds or, if no _\bi_\bds are supplied, any job, to complete
+ and returns its exit status. If none of the supplied arguments
+ is a child of the shell, or if no arguments are supplied and the
+ shell has no unwaited-for children, the exit status is 127. If
the -\b-p\bp option is supplied, the process or job identifier of the
job for which the exit status is returned is assigned to the
- variable _\bv_\ba_\br_\bn_\ba_\bm_\be named by the option argument. The variable will
- be unset initially, before any assignment. This is useful only
- when the -\b-n\bn option is supplied. Supplying the -\b-f\bf option, when
- job control is enabled, forces w\bwa\bai\bit\bt to wait for _\bi_\bd to terminate
- before returning its status, instead of returning when it
- changes status. If _\bi_\bd specifies a non-existent process or job,
- the return status is 127. If w\bwa\bai\bit\bt is interrupted by a signal,
+ variable _\bv_\ba_\br_\bn_\ba_\bm_\be named by the option argument. The variable
+ will be unset initially, before any assignment. This is useful
+ only when the -\b-n\bn option is supplied. Supplying the -\b-f\bf option,
+ when job control is enabled, forces w\bwa\bai\bit\bt to wait for _\bi_\bd to ter-
+ minate before returning its status, instead of returning when it
+ changes status. If _\bi_\bd specifies a non-existent process or job,
+ the return status is 127. If w\bwa\bai\bit\bt is interrupted by a signal,
the return status will be greater than 128, as described under
S\bSI\bIG\bGN\bNA\bAL\bLS\bS above. Otherwise, the return status is the exit status
of the last process or job waited for.
S\bSH\bHE\bEL\bLL\bL C\bCO\bOM\bMP\bPA\bAT\bTI\bIB\bBI\bIL\bLI\bIT\bTY\bY M\bMO\bOD\bDE\bE
Bash-4.0 introduced the concept of a _\bs_\bh_\be_\bl_\bl _\bc_\bo_\bm_\bp_\ba_\bt_\bi_\bb_\bi_\bl_\bi_\bt_\by _\bl_\be_\bv_\be_\bl, speci-
fied as a set of options to the shopt builtin ( c\bco\bom\bmp\bpa\bat\bt3\b31\b1, c\bco\bom\bmp\bpa\bat\bt3\b32\b2,
- c\bco\bom\bmp\bpa\bat\bt4\b40\b0, c\bco\bom\bmp\bpa\bat\bt4\b41\b1, and so on). There is only one current compatibility
- level - each option is mutually exclusive. The compatibility level is
- intended to allow users to select behavior from previous versions that
- is incompatible with newer versions while they migrate scripts to use
- current features and behavior. It's intended to be a temporary solu-
- tion.
+ c\bco\bom\bmp\bpa\bat\bt4\b40\b0, c\bco\bom\bmp\bpa\bat\bt4\b41\b1, and so on). There is only one current compatibil-
+ ity level -- each option is mutually exclusive. The compatibility
+ level is intended to allow users to select behavior from previous ver-
+ sions that is incompatible with newer versions while they migrate
+ scripts to use current features and behavior. It's intended to be a
+ temporary solution.
This section does not mention behavior that is standard for a particu-
lar version (e.g., setting c\bco\bom\bmp\bpa\bat\bt3\b32\b2 means that quoting the rhs of the
If a user enables, say, c\bco\bom\bmp\bpa\bat\bt3\b32\b2, it may affect the behavior of other
compatibility levels up to and including the current compatibility
- level. The idea is that each compatibility level controls behavior that
- changed in that version of b\bba\bas\bsh\bh, but that behavior may have been
- present in earlier versions. For instance, the change to use locale-
+ level. The idea is that each compatibility level controls behavior
+ that changed in that version of b\bba\bas\bsh\bh, but that behavior may have been
+ present in earlier versions. For instance, the change to use locale-
based comparisons with the [\b[[\b[ command came in bash-4.1, and earlier
versions used ASCII-based comparisons, so enabling c\bco\bom\bmp\bpa\bat\bt3\b32\b2 will enable
- ASCII-based comparisons as well. That granularity may not be sufficient
- for all uses, and as a result users should employ compatibility levels
- carefully. Read the documentation for a particular feature to find out
- the current behavior.
+ ASCII-based comparisons as well. That granularity may not be suffi-
+ cient for all uses, and as a result users should employ compatibility
+ levels carefully. Read the documentation for a particular feature to
+ find out the current behavior.
Bash-4.3 introduced a new shell variable: B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT. The value as-
signed to this variable (a decimal version number like 4.2, or an inte-
patibility level.
Starting with bash-4.4, b\bba\bas\bsh\bh has begun deprecating older compatibility
- levels. Eventually, the options will be removed in favor of B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bM-\b-
+ levels. Eventually, the options will be removed in favor of B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bM-\b-
P\bPA\bAT\bT.
Bash-5.0 is the final version for which there will be an individual
bash-5.0 and later versions.
The following table describes the behavior changes controlled by each
- compatibility level setting. The c\bco\bom\bmp\bpa\bat\bt_\bN_\bN tag is used as shorthand for
+ compatibility level setting. The c\bco\bom\bmp\bpa\bat\bt_\bN_\bN tag is used as shorthand for
setting the compatibility level to _\bN_\bN using one of the following mecha-
- nisms. For versions prior to bash-5.0, the compatibility level may be
- set using the corresponding c\bco\bom\bmp\bpa\bat\bt_\bN_\bN shopt option. For bash-4.3 and
+ nisms. For versions prior to bash-5.0, the compatibility level may be
+ set using the corresponding c\bco\bom\bmp\bpa\bat\bt_\bN_\bN shopt option. For bash-4.3 and
later versions, the B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT variable is preferred, and it is re-
quired for bash-5.1 and later versions.
c\bco\bom\bmp\bpa\bat\bt4\b40\b0
+\bo the <\b< and >\b> operators to the [\b[[\b[ command do not consider
the current locale when comparing strings; they use ASCII
- ordering. B\bBa\bas\bsh\bh versions prior to bash-4.1 use ASCII col-
+ ordering. B\bBa\bas\bsh\bh versions prior to bash-4.1 use ASCII col-
lation and _\bs_\bt_\br_\bc_\bm_\bp(3); bash-4.1 and later use the current
locale's collation sequence and _\bs_\bt_\br_\bc_\bo_\bl_\bl(3).
mode (the default behavior is to make them fatal errors
that cause the shell to exit)
+\bo when executing a shell function, the loop state
- (while/until/etc.) is not reset, so b\bbr\bre\bea\bak\bk or c\bco\bon\bnt\bti\bin\bnu\bue\be in
+ (while/until/etc.) is not reset, so b\bbr\bre\bea\bak\bk or c\bco\bon\bnt\bti\bin\bnu\bue\be in
that function will break or continue loops in the calling
context. Bash-4.4 and later reset the loop state to pre-
vent this
can be expanded more than once
+\bo t\bte\bes\bst\bt -\b-v\bv, when given an argument of A\bA[\b[@\b@]\b], where A\bAP\bP i\bis\bs a\ban\bn
e\bex\bxi\bis\bst\bti\bin\bng\bg a\bas\bss\bso\boc\bci\bia\bat\bti\biv\bve\be a\bar\brr\bra\bay\by,\b, w\bwi\bil\bll\bl r\bre\bet\btu\bur\brn\bn t\btr\bru\bue\be i\bif\bf t\bth\bhe\be a\bar\brr\bra\bay\by
- h\bha\bas\bs a\ban\bny\by s\bse\bet\bt e\bel\ble\bem\bme\ben\bnt\bts\bs.\b. B\bBa\bas\bsh\bh-\b-5\b5.\b.2\b2 w\bwi\bil\bll\bl l\blo\boo\bok\bk f\bfo\bor\br a\ban\bnd\bd r\bre\bep\bpo\bor\brt\bt
+ h\bha\bas\bs a\ban\bny\by s\bse\bet\bt e\bel\ble\bem\bme\ben\bnt\bts\bs.\b. B\bBa\bas\bsh\bh-\b-5\b5.\b.2\b2 w\bwi\bil\bll\bl l\blo\boo\bok\bk f\bfo\bor\br a\ban\bnd\bd r\bre\bep\bpo\bor\brt\bt
o\bon\bn a\ba k\bke\bey\by n\bna\bam\bme\bed\bd @\b@.\b.
+\b+\bo\bo the ${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br[\b[:\b:]\b]=\b=_\bv_\ba_\bl_\bu_\be} word expansion will return
_\bv_\ba_\bl_\bu_\be, before any variable-specific transformations have
- been performed (e.g., converting to lowercase). Bash-5.2
+ been performed (e.g., converting to lowercase). Bash-5.2
will return the final value assigned to the variable.
+\bo Parsing command substitutions will behave as if extended
globbing (see the description of the s\bsh\bho\bop\bpt\bt builtin above)
is enabled, so that parsing a command substitution con-
taining an extglob pattern (say, as part of a shell func-
- tion) will not fail. This assumes the intent is to enable
- extglob before the command is executed and word expan-
- sions are performed. It will fail at word expansion time
- if extglob hasn't been enabled by the time the command is
- executed.
+ tion) will not fail. This assumes the intent is to en-
+ able extglob before the command is executed and word ex-
+ pansions are performed. It will fail at word expansion
+ time if extglob hasn't been enabled by the time the com-
+ mand is executed.
R\bRE\bES\bST\bTR\bRI\bIC\bCT\bTE\bED\bD S\bSH\bHE\bEL\bLL\bL
If b\bba\bas\bsh\bh is started with the name r\brb\bba\bas\bsh\bh, or the -\b-r\br 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 be-
- haves identically to b\bba\bas\bsh\bh 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 b\bba\bas\bsh\bh with the exception that the following are
disallowed or not performed:
+\bo changing directories with c\bcd\bd
_\bP_\bo_\br_\bt_\ba_\bb_\bl_\be _\bO_\bp_\be_\br_\ba_\bt_\bi_\bn_\bg _\bS_\by_\bs_\bt_\be_\bm _\bI_\bn_\bt_\be_\br_\bf_\ba_\bc_\be _\b(_\bP_\bO_\bS_\bI_\bX_\b) _\bP_\ba_\br_\bt _\b2_\b: _\bS_\bh_\be_\bl_\bl _\ba_\bn_\bd _\bU_\bt_\bi_\bl_\bi_\b-
_\bt_\bi_\be_\bs, IEEE --
http://pubs.opengroup.org/onlinepubs/9699919799/
- http://tiswww.case.edu/~chet/bash/POSIX - a description of posix mode
+ http://tiswww.case.edu/~chet/bash/POSIX -- a description of posix mode
_\bs_\bh(1), _\bk_\bs_\bh(1), _\bc_\bs_\bh(1)
_\be_\bm_\ba_\bc_\bs(1), _\bv_\bi(1)
_\br_\be_\ba_\bd_\bl_\bi_\bn_\be(3)
chet.ramey@case.edu
B\bBU\bUG\bG R\bRE\bEP\bPO\bOR\bRT\bTS\bS
- If you find a bug in b\bba\bas\bsh\bh, you should report it. But first, you should
+ If you find a bug in b\bba\bas\bsh\bh, 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 b\bba\bas\bsh\bh. The latest version is always available from
+ version of b\bba\bas\bsh\bh. The latest version is always available from
_\bf_\bt_\bp_\b:_\b/_\b/_\bf_\bt_\bp_\b._\bg_\bn_\bu_\b._\bo_\br_\bg_\b/_\bp_\bu_\bb_\b/_\bg_\bn_\bu_\b/_\bb_\ba_\bs_\bh_\b/ and _\bh_\bt_\bt_\bp_\b:_\b/_\b/_\bg_\bi_\bt_\b._\bs_\ba_\bv_\ba_\bn_\b-
_\bn_\ba_\bh_\b._\bg_\bn_\bu_\b._\bo_\br_\bg_\b/_\bc_\bg_\bi_\bt_\b/_\bb_\ba_\bs_\bh_\b._\bg_\bi_\bt_\b/_\bs_\bn_\ba_\bp_\bs_\bh_\bo_\bt_\b/_\bb_\ba_\bs_\bh_\b-_\bm_\ba_\bs_\bt_\be_\br_\b._\bt_\ba_\br_\b._\bg_\bz.
Once you have determined that a bug actually exists, use the _\bb_\ba_\bs_\bh_\bb_\bu_\bg
- 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
+ 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 _\bb_\bu_\bg_\b-_\bb_\ba_\bs_\bh_\b@_\bg_\bn_\bu_\b._\bo_\br_\bg or posted to the Usenet newsgroup
g\bgn\bnu\bu.\b.b\bba\bas\bsh\bh.\b.b\bbu\bug\bg.
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 se-
- quence. It suffices to place the sequence of commands between parenthe-
- ses to force it into a subshell, which may be stopped as a unit.
+ 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.
Unless otherwise noted, each builtin command documented in this section
as accepting options preceded by -\b- accepts -\b--\b- to signify the end of the
options. The :\b:, t\btr\bru\bue\be, f\bfa\bal\bls\bse\be, and t\bte\bes\bst\bt/[\b[ builtins do not accept options
- and do not treat -\b--\b- specially. The e\bex\bxi\bit\bt, l\blo\bog\bgo\bou\but\bt, r\bre\bet\btu\bur\brn\bn, b\bbr\bre\bea\bak\bk, c\bco\bon\bn-\b-
+ and do not treat -\b--\b- specially. The e\bex\bxi\bit\bt, l\blo\bog\bgo\bou\but\bt, r\bre\bet\btu\bur\brn\bn, b\bbr\bre\bea\bak\bk, c\bco\bon\bn-\b-
t\bti\bin\bnu\bue\be, l\ble\bet\bt, and s\bsh\bhi\bif\bft\bt builtins accept and process arguments beginning
- with -\b- without requiring -\b--\b-. Other builtins that accept arguments but
+ with -\b- without requiring -\b--\b-. Other builtins that accept arguments but
are not specified as accepting options interpret arguments beginning
with -\b- as invalid options and require -\b--\b- to prevent this interpreta-
tion.
:\b: [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
No effect; the command does nothing beyond expanding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs
- and performing any specified redirections. The return status is
+ and performing any specified redirections. The return status is
zero.
.\b. _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
s\bso\bou\bur\brc\bce\be _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
Read and execute commands from _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be in the current shell en-
vironment and return the exit status of the last command exe-
- cuted from _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not contain a slash, file-
- names in P\bPA\bAT\bTH\bH are used to find the directory containing _\bf_\bi_\bl_\be_\b-
- _\bn_\ba_\bm_\be, but _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not need to be executable. The file
- searched for in P\bPA\bAT\bTH\bH need not be executable. When b\bba\bas\bsh\bh is not in
- _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, it searches the current directory if no file is
- found in P\bPA\bAT\bTH\bH. If the s\bso\bou\bur\brc\bce\bep\bpa\bat\bth\bh option to the s\bsh\bho\bop\bpt\bt builtin
- command is turned off, the P\bPA\bAT\bTH\bH is not searched. If any _\ba_\br_\bg_\bu_\b-
+ cuted from _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not contain a slash,
+ filenames in P\bPA\bAT\bTH\bH are used to find the directory containing
+ _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be, but _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be does not need to be executable. The file
+ searched for in P\bPA\bAT\bTH\bH need not be executable. When b\bba\bas\bsh\bh is not
+ in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, it searches the current directory if no file is
+ found in P\bPA\bAT\bTH\bH. If the s\bso\bou\bur\brc\bce\bep\bpa\bat\bth\bh option to the s\bsh\bho\bop\bpt\bt builtin
+ command is turned off, the P\bPA\bAT\bTH\bH is not searched. If any _\ba_\br_\bg_\bu_\b-
_\bm_\be_\bn_\bt_\bs are supplied, they become the positional parameters when
_\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is executed. Otherwise the positional parameters are
- unchanged. If the -\b-T\bT option is enabled, .\b. inherits any trap on
+ unchanged. If the -\b-T\bT option is enabled, .\b. inherits any trap on
D\bDE\bEB\bBU\bUG\bG; if it is not, any D\bDE\bEB\bBU\bUG\bG trap string is saved and restored
around the call to .\b., and .\b. unsets the D\bDE\bEB\bBU\bUG\bG trap while it exe-
cutes. If -\b-T\bT is not set, and the sourced file changes the D\bDE\bEB\bBU\bUG\bG
- trap, the new value is retained when .\b. completes. The return
+ trap, the new value is retained when .\b. completes. The return
status is the status of the last command exited within the
script (0 if no commands are executed), and false if _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is
not found or cannot be read.
a\bal\bli\bia\bas\bs [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ...]
A\bAl\bli\bia\bas\bs with no arguments or with the -\b-p\bp option prints the list of
- aliases in the form a\bal\bli\bia\bas\bs _\bn_\ba_\bm_\be=_\bv_\ba_\bl_\bu_\be on standard output. When
+ aliases in the form a\bal\bli\bia\bas\bs _\bn_\ba_\bm_\be=_\bv_\ba_\bl_\bu_\be on standard output. When
arguments are supplied, an alias is defined for each _\bn_\ba_\bm_\be whose
- _\bv_\ba_\bl_\bu_\be is given. A trailing space in _\bv_\ba_\bl_\bu_\be causes the next word
+ _\bv_\ba_\bl_\bu_\be is given. A trailing space in _\bv_\ba_\bl_\bu_\be causes the next word
to be checked for alias substitution when the alias is expanded.
For each _\bn_\ba_\bm_\be in the argument list for which no _\bv_\ba_\bl_\bu_\be is sup-
- plied, the name and value of the alias is printed. A\bAl\bli\bia\bas\bs returns
- true unless a _\bn_\ba_\bm_\be is given for which no alias has been defined.
+ plied, the name and value of the alias is printed. A\bAl\bli\bia\bas\bs re-
+ turns true unless a _\bn_\ba_\bm_\be is given for which no alias has been
+ defined.
b\bbg\bg [_\bj_\bo_\bb_\bs_\bp_\be_\bc ...]
- Resume each suspended job _\bj_\bo_\bb_\bs_\bp_\be_\bc in the background, as if it
- had been started with &\b&. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, the shell's
- notion of the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. b\bbg\bg _\bj_\bo_\bb_\bs_\bp_\be_\bc returns 0 unless
- run when job control is disabled or, when run with job control
- enabled, any specified _\bj_\bo_\bb_\bs_\bp_\be_\bc was not found or was started
+ Resume each suspended job _\bj_\bo_\bb_\bs_\bp_\be_\bc in the background, as if it
+ had been started with &\b&. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, the shell's
+ notion of the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. b\bbg\bg _\bj_\bo_\bb_\bs_\bp_\be_\bc returns 0 unless
+ run when job control is disabled or, when run with job control
+ enabled, any specified _\bj_\bo_\bb_\bs_\bp_\be_\bc was not found or was started
without job control.
b\bbi\bin\bnd\bd [-\b-m\bm _\bk_\be_\by_\bm_\ba_\bp] [-\b-l\blp\bps\bsv\bvP\bPS\bSV\bVX\bX]
b\bbi\bin\bnd\bd [-\b-m\bm _\bk_\be_\by_\bm_\ba_\bp] _\bk_\be_\by_\bs_\be_\bq:_\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be
b\bbi\bin\bnd\bd [-\b-m\bm _\bk_\be_\by_\bm_\ba_\bp] _\bk_\be_\by_\bs_\be_\bq:_\br_\be_\ba_\bd_\bl_\bi_\bn_\be_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd
b\bbi\bin\bnd\bd _\br_\be_\ba_\bd_\bl_\bi_\bn_\be_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b-_\bl_\bi_\bn_\be
- Display current r\bre\bea\bad\bdl\bli\bin\bne\be key and function bindings, bind a key
- sequence to a r\bre\bea\bad\bdl\bli\bin\bne\be function or macro, or set a r\bre\bea\bad\bdl\bli\bin\bne\be
+ Display current r\bre\bea\bad\bdl\bli\bin\bne\be key and function bindings, bind a key
+ sequence to a r\bre\bea\bad\bdl\bli\bin\bne\be function or macro, or set a r\bre\bea\bad\bdl\bli\bin\bne\be
variable. Each non-option argument is a command as it would ap-
- pear in a r\bre\bea\bad\bdl\bli\bin\bne\be initialization file such as _\b._\bi_\bn_\bp_\bu_\bt_\br_\bc, 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,
+ pear in a r\bre\bea\bad\bdl\bli\bin\bne\be initialization file such as _\b._\bi_\bn_\bp_\bu_\bt_\br_\bc, 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:
-\b-m\bm _\bk_\be_\by_\bm_\ba_\bp
Use _\bk_\be_\by_\bm_\ba_\bp as the keymap to be affected by the subsequent
- bindings. Acceptable _\bk_\be_\by_\bm_\ba_\bp names are _\be_\bm_\ba_\bc_\bs_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\b-
- _\bd_\ba_\br_\bd_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bm_\be_\bt_\ba_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bc_\bt_\bl_\bx_\b, _\bv_\bi_\b, _\bv_\bi_\b-_\bm_\bo_\bv_\be_\b, _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd,
- and _\bv_\bi_\b-_\bi_\bn_\bs_\be_\br_\bt. _\bv_\bi is equivalent to _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd (_\bv_\bi_\b-_\bm_\bo_\bv_\be is
- also a synonym); _\be_\bm_\ba_\bc_\bs is equivalent to _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd.
+ bindings. Acceptable _\bk_\be_\by_\bm_\ba_\bp names are _\be_\bm_\ba_\bc_\bs_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\b-
+ _\bd_\ba_\br_\bd_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bm_\be_\bt_\ba_\b, _\be_\bm_\ba_\bc_\bs_\b-_\bc_\bt_\bl_\bx_\b, _\bv_\bi_\b, _\bv_\bi_\b-_\bm_\bo_\bv_\be_\b, _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd,
+ and _\bv_\bi_\b-_\bi_\bn_\bs_\be_\br_\bt. _\bv_\bi is equivalent to _\bv_\bi_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd (_\bv_\bi_\b-_\bm_\bo_\bv_\be
+ is also a synonym); _\be_\bm_\ba_\bc_\bs is equivalent to _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\b-
+ _\bd_\ba_\br_\bd.
-\b-l\bl List the names of all r\bre\bea\bad\bdl\bli\bin\bne\be functions.
-\b-p\bp Display r\bre\bea\bad\bdl\bli\bin\bne\be function names and bindings in such a
way that they can be re-read.
Cause _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd to be executed whenever _\bk_\be_\by_\bs_\be_\bq is en-
tered. The separator between _\bk_\be_\by_\bs_\be_\bq and _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd is
either whitespace or a colon optionally followed by
- whitespace. If the separator is whitespace, _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd
- must be enclosed in double quotes and r\bre\bea\bad\bdl\bli\bin\bne\be expands
- any of its special backslash-escapes in _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd be-
- fore saving it. If the separator is a colon, any enclos-
- ing double quotes are optional, and r\bre\bea\bad\bdl\bli\bin\bne\be does not ex-
- pand the command string before saving it. Since the en-
- tire key binding expression must be a single argument, it
- should be enclosed in quotes. When _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd is exe-
- cuted, the shell sets the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE variable to the
- contents of the r\bre\bea\bad\bdl\bli\bin\bne\be line buffer and the R\bRE\bEA\bAD\bD-\b-
- L\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT and R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK variables to the current lo-
- cation of the insertion point and the saved insertion
- point (the mark), respectively. The shell assigns any nu-
- meric argument the user supplied to the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_A\bAR\bRG\bGU\bUM\bME\bEN\bNT\bT
- variable. If there was no argument, that variable is not
- set. If the executed command changes the value of any of
- R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE, R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT, or R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK, those
- new values will be reflected in the editing state.
+ whitespace. If the separator is whitespace, _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\b-
+ _\bm_\ba_\bn_\bd must be enclosed in double quotes and r\bre\bea\bad\bdl\bli\bin\bne\be ex-
+ pands any of its special backslash-escapes in _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\b-
+ _\bm_\ba_\bn_\bd before saving it. If the separator is a colon, any
+ enclosing double quotes are optional, and r\bre\bea\bad\bdl\bli\bin\bne\be does
+ not expand the command string before saving it. Since
+ the entire key binding expression must be a single argu-
+ ment, it should be enclosed in quotes. When _\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\b-
+ _\bm_\ba_\bn_\bd is executed, the shell sets the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE vari-
+ able to the contents of the r\bre\bea\bad\bdl\bli\bin\bne\be line buffer and the
+ R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT and R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK variables to the current
+ location of the insertion point and the saved insertion
+ point (the mark), respectively. The shell assigns any
+ numeric argument the user supplied to the R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_A\bAR\bRG\bGU\bU-\b-
+ M\bME\bEN\bNT\bT variable. If there was no argument, that variable
+ is not set. If the executed command changes the value of
+ any of R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE, R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT, or R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_M\bMA\bAR\bRK\bK,
+ those new values will be reflected in the editing state.
-\b-X\bX List all key sequences bound to shell commands and the
associated commands in a format that can be reused as in-
put.
an error occurred.
b\bbr\bre\bea\bak\bk [_\bn]
- Exit from within a f\bfo\bor\br, w\bwh\bhi\bil\ble\be, u\bun\bnt\bti\bil\bl, or s\bse\bel\ble\bec\bct\bt loop. If _\bn is
- specified, break _\bn levels. _\bn must be >= 1. If _\bn is greater than
- the number of enclosing loops, all enclosing loops are exited.
- The return value is 0 unless _\bn is not greater than or equal to
- 1.
+ Exit from within a f\bfo\bor\br, w\bwh\bhi\bil\ble\be, u\bun\bnt\bti\bil\bl, or s\bse\bel\ble\bec\bct\bt loop. If _\bn is
+ specified, break _\bn levels. _\bn must be >= 1. If _\bn is greater
+ than the number of enclosing loops, all enclosing loops are ex-
+ ited. The return value is 0 unless _\bn is not greater than or
+ equal to 1.
b\bbu\bui\bil\blt\bti\bin\bn _\bs_\bh_\be_\bl_\bl_\b-_\bb_\bu_\bi_\bl_\bt_\bi_\bn [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
Execute the specified shell builtin, passing it _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs, and
- return its exit status. This is useful when defining a function
+ return its exit status. This is useful when defining a function
whose name is the same as a shell builtin, retaining the func-
- tionality of the builtin within the function. The c\bcd\bd builtin is
- commonly redefined this way. The return status is false if
+ tionality of the builtin within the function. The c\bcd\bd builtin is
+ commonly redefined this way. The return status is false if
_\bs_\bh_\be_\bl_\bl_\b-_\bb_\bu_\bi_\bl_\bt_\bi_\bn is not a shell builtin command.
c\bca\bal\bll\ble\ber\br [_\be_\bx_\bp_\br]
Returns the context of any active subroutine call (a shell func-
- tion or a script executed with the .\b. or s\bso\bou\bur\brc\bce\be builtins). With-
+ tion or a script executed with the .\b. or s\bso\bou\bur\brc\bce\be builtins). With-
out _\be_\bx_\bp_\br, c\bca\bal\bll\ble\ber\br 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 _\be_\bx_\bp_\br, c\bca\bal\bll\ble\ber\br 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.
+ 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 _\be_\bx_\bp_\br does not correspond to a valid position in
the call stack.
c\bcd\bd [-\b-L\bL|[-\b-P\bP [-\b-e\be]]] [-@] [_\bd_\bi_\br]
- Change the current directory to _\bd_\bi_\br. if _\bd_\bi_\br is not supplied, the
- value of the H\bHO\bOM\bME\bE shell variable is the default. The variable
- C\bCD\bDP\bPA\bAT\bTH\bH defines the search path for the directory containing _\bd_\bi_\br:
- each directory name in C\bCD\bDP\bPA\bAT\bTH\bH is searched for _\bd_\bi_\br. Alternative
- directory names in C\bCD\bDP\bPA\bAT\bTH\bH are separated by a colon (:). A null
- directory name in C\bCD\bDP\bPA\bAT\bTH\bH is the same as the current directory,
- i.e., ``.\b.''. If _\bd_\bi_\br begins with a slash (/), then C\bCD\bDP\bPA\bAT\bTH\bH is not
- used. The -\b-P\bP option causes c\bcd\bd to use the physical directory
- structure by resolving symbolic links while traversing _\bd_\bi_\br and
- before processing instances of _\b._\b. in _\bd_\bi_\br (see also the -\b-P\bP option
- to the s\bse\bet\bt builtin command); the -\b-L\bL option forces symbolic links
- to be followed by resolving the link after processing instances
- of _\b._\b. in _\bd_\bi_\br. If _\b._\b. appears in _\bd_\bi_\br, it is processed by removing
- the immediately previous pathname component from _\bd_\bi_\br, back to a
- slash or the beginning of _\bd_\bi_\br. If the -\b-e\be option is supplied with
- -\b-P\bP, and the current working directory cannot be successfully de-
- termined after a successful directory change, c\bcd\bd will return an
- unsuccessful status. On systems that support it, the -\b-@\b@ option
- presents the extended attributes associated with a file as a di-
- rectory. An argument of -\b- is converted to $\b$O\bOL\bLD\bDP\bPW\bWD\bD before the di-
- rectory change is attempted. If a non-empty directory name from
- C\bCD\bDP\bPA\bAT\bTH\bH is used, or if -\b- is the first argument, and the directory
- change is successful, the absolute pathname of the new working
- directory is written to the standard output. If the directory
- change is successful, c\bcd\bd sets the value of the P\bPW\bWD\bD environment
- variable to the new directory name, and sets the O\bOL\bLD\bDP\bPW\bWD\bD environ-
- ment variable to the value of the current working directory be-
- fore the change. The return value is true if the directory was
- successfully changed; false otherwise.
+ Change the current directory to _\bd_\bi_\br. if _\bd_\bi_\br is not supplied,
+ the value of the H\bHO\bOM\bME\bE shell variable is the default. The vari-
+ able C\bCD\bDP\bPA\bAT\bTH\bH defines the search path for the directory containing
+ _\bd_\bi_\br: each directory name in C\bCD\bDP\bPA\bAT\bTH\bH is searched for _\bd_\bi_\br. Alter-
+ native directory names in C\bCD\bDP\bPA\bAT\bTH\bH are separated by a colon (:).
+ A null directory name in C\bCD\bDP\bPA\bAT\bTH\bH is the same as the current di-
+ rectory, i.e., ``.\b.''. If _\bd_\bi_\br begins with a slash (/), then C\bCD\bD-\b-
+ P\bPA\bAT\bTH\bH is not used. The -\b-P\bP option causes c\bcd\bd to use the physical
+ directory structure by resolving symbolic links while traversing
+ _\bd_\bi_\br and before processing instances of _\b._\b. in _\bd_\bi_\br (see also the
+ -\b-P\bP option to the s\bse\bet\bt builtin command); the -\b-L\bL option forces sym-
+ bolic links to be followed by resolving the link after process-
+ ing instances of _\b._\b. in _\bd_\bi_\br. If _\b._\b. appears in _\bd_\bi_\br, it is pro-
+ cessed by removing the immediately previous pathname component
+ from _\bd_\bi_\br, back to a slash or the beginning of _\bd_\bi_\br. If the -\b-e\be
+ option is supplied with -\b-P\bP, and the current working directory
+ cannot be successfully determined after a successful directory
+ change, c\bcd\bd will return an unsuccessful status. On systems that
+ support it, the -\b-@\b@ option presents the extended attributes asso-
+ ciated with a file as a directory. An argument of -\b- is con-
+ verted to $\b$O\bOL\bLD\bDP\bPW\bWD\bD before the directory change is attempted. If
+ a non-empty directory name from C\bCD\bDP\bPA\bAT\bTH\bH is used, or if -\b- is the
+ first argument, and the directory change is successful, the ab-
+ solute pathname of the new working directory is written to the
+ standard output. If the directory change is successful, c\bcd\bd sets
+ the value of the P\bPW\bWD\bD environment variable to the new directory
+ name, and sets the O\bOL\bLD\bDP\bPW\bWD\bD environment variable to the value of
+ the current working directory before the change. The return
+ value is true if the directory was successfully changed; false
+ otherwise.
c\bco\bom\bmm\bma\ban\bnd\bd [-\b-p\bpV\bVv\bv] _\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\ba_\br_\bg ...]
- Run _\bc_\bo_\bm_\bm_\ba_\bn_\bd with _\ba_\br_\bg_\bs suppressing the normal shell function
+ Run _\bc_\bo_\bm_\bm_\ba_\bn_\bd with _\ba_\br_\bg_\bs suppressing the normal shell function
lookup. Only builtin commands or commands found in the P\bPA\bAT\bTH\bH are
- executed. If the -\b-p\bp option is given, the search for _\bc_\bo_\bm_\bm_\ba_\bn_\bd is
- performed using a default value for P\bPA\bAT\bTH\bH that is guaranteed to
- find all of the standard utilities. If either the -\b-V\bV or -\b-v\bv op-
- tion is supplied, a description of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is printed. The -\b-v\bv
- option causes a single word indicating the command or filename
+ executed. If the -\b-p\bp option is given, the search for _\bc_\bo_\bm_\bm_\ba_\bn_\bd is
+ performed using a default value for P\bPA\bAT\bTH\bH that is guaranteed to
+ find all of the standard utilities. If either the -\b-V\bV or -\b-v\bv op-
+ tion is supplied, a description of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is printed. The -\b-v\bv
+ option causes a single word indicating the command or filename
used to invoke _\bc_\bo_\bm_\bm_\ba_\bn_\bd to be displayed; the -\b-V\bV option produces a
- more verbose description. If the -\b-V\bV or -\b-v\bv option is supplied,
- the exit status is 0 if _\bc_\bo_\bm_\bm_\ba_\bn_\bd was found, and 1 if not. If nei-
- ther option is supplied and an error occurred or _\bc_\bo_\bm_\bm_\ba_\bn_\bd cannot
- be found, the exit status is 127. Otherwise, the exit status of
- the c\bco\bom\bmm\bma\ban\bnd\bd builtin is the exit status of _\bc_\bo_\bm_\bm_\ba_\bn_\bd.
+ more verbose description. If the -\b-V\bV or -\b-v\bv option is supplied,
+ the exit status is 0 if _\bc_\bo_\bm_\bm_\ba_\bn_\bd was found, and 1 if not. If
+ neither option is supplied and an error occurred or _\bc_\bo_\bm_\bm_\ba_\bn_\bd can-
+ not be found, the exit status is 127. Otherwise, the exit sta-
+ tus of the c\bco\bom\bmm\bma\ban\bnd\bd builtin is the exit status of _\bc_\bo_\bm_\bm_\ba_\bn_\bd.
c\bco\bom\bmp\bpg\bge\ben\bn [-\b-V\bV _\bv_\ba_\br_\bn_\ba_\bm_\be] [_\bo_\bp_\bt_\bi_\bo_\bn] [_\bw_\bo_\br_\bd]
- Generate possible completion matches for _\bw_\bo_\br_\bd according to the
- _\bo_\bp_\bt_\bi_\bo_\bns, which may be any option accepted by the c\bco\bom\bmp\bpl\ble\bet\bte\be
+ Generate possible completion matches for _\bw_\bo_\br_\bd according to the
+ _\bo_\bp_\bt_\bi_\bo_\bns, which may be any option accepted by the c\bco\bom\bmp\bpl\ble\bet\bte\be
builtin with the exceptions of -\b-p\bp, -\b-r\br, -\b-D\bD, -\b-E\bE, and -\b-I\bI, and write
- the matches to the standard output. If the -\b-V\bV option is sup-
+ the matches to the standard output. If the -\b-V\bV option is sup-
plied, c\bco\bom\bmp\bpg\bge\ben\bn stores the generated completions into the indexed
- array variable _\bv_\ba_\br_\bn_\ba_\bm_\be instead of writing them to the standard
- output. When using the -\b-F\bF or -\b-C\bC options, the various shell vari-
- ables set by the programmable completion facilities, while
+ array variable _\bv_\ba_\br_\bn_\ba_\bm_\be instead of writing them to the standard
+ output. When using the -\b-F\bF or -\b-C\bC 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 program-
mable completion code had generated them directly from a comple-
- tion specification with the same flags. If _\bw_\bo_\br_\bd is specified,
+ tion specification with the same flags. If _\bw_\bo_\br_\bd is specified,
only those completions matching _\bw_\bo_\br_\bd 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.
c\bco\bom\bmp\bpl\ble\bet\bte\be [-\b-a\bab\bbc\bcd\bde\bef\bfg\bgj\bjk\bks\bsu\buv\bv] [-\b-o\bo _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn] [-\b-D\bDE\bEI\bI] [-\b-A\bA _\ba_\bc_\bt_\bi_\bo_\bn]
[-\b-G\bG _\bg_\bl_\bo_\bb_\bp_\ba_\bt] [-\b-W\bW _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt] [-\b-F\bF _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn] [-\b-C\bC _\bc_\bo_\bm_\bm_\ba_\bn_\bd]
[-\b-X\bX _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt] [-\b-P\bP _\bp_\br_\be_\bf_\bi_\bx] [-\b-S\bS _\bs_\bu_\bf_\bf_\bi_\bx] _\bn_\ba_\bm_\be [_\bn_\ba_\bm_\be _\b._\b._\b.]
c\bco\bom\bmp\bpl\ble\bet\bte\be -\b-p\bpr\br [-\b-D\bDE\bEI\bI] [_\bn_\ba_\bm_\be ...]
- Specify how arguments to each _\bn_\ba_\bm_\be should be completed. If the
- -\b-p\bp 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 -\b-r\br option removes a completion speci-
- fication for each _\bn_\ba_\bm_\be, or, if no _\bn_\ba_\bm_\bes are supplied, all com-
- pletion specifications. The -\b-D\bD option indicates that other sup-
- plied options and actions should apply to the ``default'' com-
- mand completion; that is, completion attempted on a command for
- which no completion has previously been defined. The -\b-E\bE option
- indicates that other supplied options and actions should apply
- to ``empty'' command completion; that is, completion attempted
- on a blank line. The -\b-I\bI option indicates that other supplied op-
- tions and actions should apply to completion on the initial non-
- assignment word on the line, or after a command delimiter such
- as ;\b; or |\b|, which is usually command name completion. If multiple
- options are supplied, the -\b-D\bD option takes precedence over -\b-E\bE,
- and both take precedence over -\b-I\bI. If any of -\b-D\bD, -\b-E\bE, or -\b-I\bI are
- supplied, any other _\bn_\ba_\bm_\be arguments are ignored; these comple-
- tions only apply to the case specified by the option.
-
- The process of applying these completion specifications when
+ Specify how arguments to each _\bn_\ba_\bm_\be should be completed. If the
+ -\b-p\bp 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 -\b-r\br option removes a completion spec-
+ ification for each _\bn_\ba_\bm_\be, or, if no _\bn_\ba_\bm_\bes are supplied, all com-
+ pletion specifications. The -\b-D\bD option indicates that other sup-
+ plied options and actions should apply to the ``default'' com-
+ mand completion; that is, completion attempted on a command for
+ which no completion has previously been defined. The -\b-E\bE option
+ indicates that other supplied options and actions should apply
+ to ``empty'' command completion; that is, completion attempted
+ on a blank line. The -\b-I\bI option indicates that other supplied
+ options and actions should apply to completion on the initial
+ non-assignment word on the line, or after a command delimiter
+ such as ;\b; or |\b|, which is usually command name completion. If
+ multiple options are supplied, the -\b-D\bD option takes precedence
+ over -\b-E\bE, and both take precedence over -\b-I\bI. If any of -\b-D\bD, -\b-E\bE, or
+ -\b-I\bI are supplied, any other _\bn_\ba_\bm_\be arguments are ignored; these
+ completions only apply to the case specified by the option.
+
+ The process of applying these completion specifications when
word completion is attempted is described in _\bb_\ba_\bs_\bh_\b(_\b1_\b).
- Other options, if specified, have the following meanings. The
- arguments to the -\b-G\bG, -\b-W\bW, and -\b-X\bX options (and, if necessary, the
- -\b-P\bP and -\b-S\bS options) should be quoted to protect them from expan-
+ Other options, if specified, have the following meanings. The
+ arguments to the -\b-G\bG, -\b-W\bW, and -\b-X\bX options (and, if necessary, the
+ -\b-P\bP and -\b-S\bS options) should be quoted to protect them from expan-
sion before the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin is invoked.
-\b-o\bo _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn
- The _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn controls several aspects of the comp-
- spec's behavior beyond the simple generation of comple-
- tions. _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn may be one of:
+ The _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn controls several aspects of the comp-
+ spec's behavior beyond the simple generation of comple-
+ tions. _\bc_\bo_\bm_\bp_\b-_\bo_\bp_\bt_\bi_\bo_\bn may be one of:
b\bba\bas\bsh\bhd\bde\bef\bfa\bau\bul\blt\bt
Perform the rest of the default b\bba\bas\bsh\bh completions
if the compspec generates no matches.
- d\bde\bef\bfa\bau\bul\blt\bt Use readline's default filename completion if
+ d\bde\bef\bfa\bau\bul\blt\bt Use readline's default filename completion if
the compspec generates no matches.
d\bdi\bir\brn\bna\bam\bme\bes\bs
- Perform directory name completion if the comp-
+ Perform directory name completion if the comp-
spec generates no matches.
f\bfi\bil\ble\ben\bna\bam\bme\bes\bs
- 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.
f\bfu\bul\bll\blq\bqu\buo\bot\bte\be
- Tell readline to quote all the completed words
+ Tell readline to quote all the completed words
even if they are not filenames.
- n\bno\boq\bqu\buo\bot\bte\be Tell readline not to quote the completed words
- if they are filenames (quoting filenames is the
+ n\bno\boq\bqu\buo\bot\bte\be Tell readline not to quote the completed words
+ if they are filenames (quoting filenames is the
default).
- n\bno\bos\bso\bor\brt\bt Tell readline not to sort the list of possible
+ n\bno\bos\bso\bor\brt\bt Tell readline not to sort the list of possible
completions alphabetically.
- n\bno\bos\bsp\bpa\bac\bce\be Tell readline not to append a space (the de-
- fault) to words completed at the end of the
+ n\bno\bos\bsp\bpa\bac\bce\be Tell readline not to append a space (the de-
+ fault) to words completed at the end of the
line.
p\bpl\blu\bus\bsd\bdi\bir\brs\bs
- After any matches defined by the compspec are
+ After any matches defined by the compspec are
generated, directory name completion is at-
tempted and any matches are added to the results
of the other actions.
-\b-A\bA _\ba_\bc_\bt_\bi_\bo_\bn
- The _\ba_\bc_\bt_\bi_\bo_\bn may be one of the following to generate a
+ The _\ba_\bc_\bt_\bi_\bo_\bn may be one of the following to generate a
list of possible completions:
- a\bal\bli\bia\bas\bs Alias names. May also be specified as -\b-a\ba.
+ a\bal\bli\bia\bas\bs Alias names. May also be specified as -\b-a\ba.
a\bar\brr\bra\bay\byv\bva\bar\br
Array variable names.
b\bbi\bin\bnd\bdi\bin\bng\bg R\bRe\bea\bad\bdl\bli\bin\bne\be key binding names.
- b\bbu\bui\bil\blt\bti\bin\bn Names of shell builtin commands. May also be
+ b\bbu\bui\bil\blt\bti\bin\bn Names of shell builtin commands. May also be
specified as -\b-b\bb.
- c\bco\bom\bmm\bma\ban\bnd\bd Command names. May also be specified as -\b-c\bc.
+ c\bco\bom\bmm\bma\ban\bnd\bd Command names. May also be specified as -\b-c\bc.
d\bdi\bir\bre\bec\bct\bto\bor\bry\by
- Directory names. May also be specified as -\b-d\bd.
+ Directory names. May also be specified as -\b-d\bd.
d\bdi\bis\bsa\bab\bbl\ble\bed\bd
Names of disabled shell builtins.
e\ben\bna\bab\bbl\ble\bed\bd Names of enabled shell builtins.
- e\bex\bxp\bpo\bor\brt\bt Names of exported shell variables. May also be
+ e\bex\bxp\bpo\bor\brt\bt Names of exported shell variables. May also be
specified as -\b-e\be.
- f\bfi\bil\ble\be File names. May also be specified as -\b-f\bf.
+ f\bfi\bil\ble\be File names. May also be specified as -\b-f\bf.
f\bfu\bun\bnc\bct\bti\bio\bon\bn
Names of shell functions.
- g\bgr\bro\bou\bup\bp Group names. May also be specified as -\b-g\bg.
+ g\bgr\bro\bou\bup\bp Group names. May also be specified as -\b-g\bg.
h\bhe\bel\blp\bpt\bto\bop\bpi\bic\bc
Help topics as accepted by the h\bhe\bel\blp\bp builtin.
h\bho\bos\bst\btn\bna\bam\bme\be
- Hostnames, as taken from the file specified by
+ Hostnames, as taken from the file specified by
the H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE shell variable.
- j\bjo\bob\bb Job names, if job control is active. May also be
- specified as -\b-j\bj.
- k\bke\bey\byw\bwo\bor\brd\bd Shell reserved words. May also be specified as
+ j\bjo\bob\bb Job names, if job control is active. May also
+ be specified as -\b-j\bj.
+ k\bke\bey\byw\bwo\bor\brd\bd Shell reserved words. May also be specified as
-\b-k\bk.
r\bru\bun\bnn\bni\bin\bng\bg Names of running jobs, if job control is active.
- s\bse\ber\brv\bvi\bic\bce\be Service names. May also be specified as -\b-s\bs.
- s\bse\bet\bto\bop\bpt\bt Valid arguments for the -\b-o\bo option to the s\bse\bet\bt
+ s\bse\ber\brv\bvi\bic\bce\be Service names. May also be specified as -\b-s\bs.
+ s\bse\bet\bto\bop\bpt\bt Valid arguments for the -\b-o\bo option to the s\bse\bet\bt
builtin.
- s\bsh\bho\bop\bpt\bt Shell option names as accepted by the s\bsh\bho\bop\bpt\bt
+ s\bsh\bho\bop\bpt\bt Shell option names as accepted by the s\bsh\bho\bop\bpt\bt
builtin.
s\bsi\big\bgn\bna\bal\bl Signal names.
s\bst\bto\bop\bpp\bpe\bed\bd Names of stopped jobs, if job control is active.
- u\bus\bse\ber\br User names. May also be specified as -\b-u\bu.
+ u\bus\bse\ber\br User names. May also be specified as -\b-u\bu.
v\bva\bar\bri\bia\bab\bbl\ble\be
- Names of all shell variables. May also be speci-
- fied as -\b-v\bv.
+ Names of all shell variables. May also be spec-
+ ified as -\b-v\bv.
-\b-C\bC _\bc_\bo_\bm_\bm_\ba_\bn_\bd
- _\bc_\bo_\bm_\bm_\ba_\bn_\bd is executed in a subshell environment, and its
- output is used as the possible completions. Arguments
+ _\bc_\bo_\bm_\bm_\ba_\bn_\bd is executed in a subshell environment, and its
+ output is used as the possible completions. Arguments
are passed as with the -\b-F\bF option.
-\b-F\bF _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn
- The shell function _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn is executed in the current
- shell environment. When the function is executed, the
+ The shell function _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn is executed in the current
+ shell environment. When the function is executed, the
first argument ($\b$1\b1) is the name of the command whose ar-
guments are being completed, the second argument ($\b$2\b2) is
the word being completed, and the third argument ($\b$3\b3) is
- the word preceding the word being completed on the cur-
- rent command line. When it finishes, the possible com-
- pletions are retrieved from the value of the C\bCO\bOM\bMP\bPR\bRE\bEP\bPL\bLY\bY
+ the word preceding the word being completed on the cur-
+ rent command line. When it finishes, the possible com-
+ pletions are retrieved from the value of the C\bCO\bOM\bMP\bPR\bRE\bEP\bPL\bLY\bY
array variable.
-\b-G\bG _\bg_\bl_\bo_\bb_\bp_\ba_\bt
- The pathname expansion pattern _\bg_\bl_\bo_\bb_\bp_\ba_\bt is expanded to
+ The pathname expansion pattern _\bg_\bl_\bo_\bb_\bp_\ba_\bt is expanded to
generate the possible completions.
-\b-P\bP _\bp_\br_\be_\bf_\bi_\bx
- _\bp_\br_\be_\bf_\bi_\bx is added at the beginning of each possible com-
+ _\bp_\br_\be_\bf_\bi_\bx is added at the beginning of each possible com-
pletion after all other options have been applied.
-\b-S\bS _\bs_\bu_\bf_\bf_\bi_\bx
_\bs_\bu_\bf_\bf_\bi_\bx is appended to each possible completion after all
other options have been applied.
-\b-W\bW _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt
- The _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt is split using the characters in the I\bIF\bFS\bS
- special variable as delimiters, and each resultant word
- is expanded. Shell quoting is honored within _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt,
+ The _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt is split using the characters in the I\bIF\bFS\bS
+ special variable as delimiters, and each resultant word
+ is expanded. Shell quoting is honored within _\bw_\bo_\br_\bd_\bl_\bi_\bs_\bt,
in order to provide a mechanism for the words to contain
- shell metacharacters or characters in the value of I\bIF\bFS\bS.
- The possible completions are the members of the resul-
+ shell metacharacters or characters in the value of I\bIF\bFS\bS.
+ The possible completions are the members of the resul-
tant list which match the word being completed.
-\b-X\bX _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt
- _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt is a pattern as used for pathname expansion.
+ _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt is a pattern as used for pathname expansion.
It is applied to the list of possible completions gener-
- ated by the preceding options and arguments, and each
- completion matching _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt is removed from the list.
- A leading !\b! in _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt negates the pattern; in this
+ ated by the preceding options and arguments, and each
+ completion matching _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt is removed from the list.
+ A leading !\b! in _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt negates the pattern; in this
case, any completion not matching _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt is removed.
- The return value is true unless an invalid option is supplied,
+ The return value is true unless an invalid option is supplied,
an option other than -\b-p\bp, -\b-r\br, -\b-D\bD, -\b-E\bE, or -\b-I\bI is supplied without a
- _\bn_\ba_\bm_\be argument, an attempt is made to remove a completion speci-
+ _\bn_\ba_\bm_\be argument, an attempt is made to remove a completion speci-
fication for a _\bn_\ba_\bm_\be for which no specification exists, or an er-
ror occurs adding a completion specification.
c\bco\bom\bmp\bpo\bop\bpt\bt [-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn] [-\b-D\bDE\bEI\bI] [+\b+o\bo _\bo_\bp_\bt_\bi_\bo_\bn] [_\bn_\ba_\bm_\be]
- Modify completion options for each _\bn_\ba_\bm_\be according to the _\bo_\bp_\b-
+ Modify completion options for each _\bn_\ba_\bm_\be according to the _\bo_\bp_\b-
_\bt_\bi_\bo_\bns, or for the currently-executing completion if no _\bn_\ba_\bm_\bes are
- supplied. If no _\bo_\bp_\bt_\bi_\bo_\bns are given, display the completion op-
- tions for each _\bn_\ba_\bm_\be or the current completion. The possible val-
- ues of _\bo_\bp_\bt_\bi_\bo_\bn are those valid for the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin described
- above. The -\b-D\bD option indicates that other supplied options
- should apply to the ``default'' command completion; that is,
- completion attempted on a command for which no completion has
- previously been defined. The -\b-E\bE option indicates that other sup-
- plied options should apply to ``empty'' command completion; that
- is, completion attempted on a blank line. The -\b-I\bI option indi-
- cates that other supplied options should apply to completion on
- the initial non-assignment word on the line, or after a command
- delimiter such as ;\b; or |\b|, which is usually command name comple-
- tion.
+ supplied. If no _\bo_\bp_\bt_\bi_\bo_\bns are given, display the completion op-
+ tions for each _\bn_\ba_\bm_\be or the current completion. The possible
+ values of _\bo_\bp_\bt_\bi_\bo_\bn are those valid for the c\bco\bom\bmp\bpl\ble\bet\bte\be builtin de-
+ scribed above. The -\b-D\bD option indicates that other supplied op-
+ tions should apply to the ``default'' command completion; that
+ is, completion attempted on a command for which no completion
+ has previously been defined. The -\b-E\bE option indicates that other
+ supplied options should apply to ``empty'' command completion;
+ that is, completion attempted on a blank line. The -\b-I\bI option
+ indicates that other supplied options should apply to completion
+ on the initial non-assignment word on the line, or after a com-
+ mand delimiter such as ;\b; or |\b|, which is usually command name
+ completion.
- The return value is true unless an invalid option is supplied,
+ The return value is true unless an invalid option is supplied,
an attempt is made to modify the options for a _\bn_\ba_\bm_\be for which no
completion specification exists, or an output error occurs.
c\bco\bon\bnt\bti\bin\bnu\bue\be [_\bn]
Resume the next iteration of the enclosing f\bfo\bor\br, w\bwh\bhi\bil\ble\be, u\bun\bnt\bti\bil\bl, or
- s\bse\bel\ble\bec\bct\bt loop. If _\bn is specified, resume at the _\bnth enclosing
- loop. _\bn must be >= 1. If _\bn is greater than the number of enclos-
- ing loops, the last enclosing loop (the ``top-level'' loop) is
- resumed. The return value is 0 unless _\bn is not greater than or
- equal to 1.
+ s\bse\bel\ble\bec\bct\bt loop. If _\bn is specified, resume at the _\bnth enclosing
+ loop. _\bn must be >= 1. If _\bn is greater than the number of en-
+ closing loops, the last enclosing loop (the ``top-level'' loop)
+ is resumed. The return value is 0 unless _\bn is not greater than
+ or equal to 1.
d\bde\bec\bcl\bla\bar\bre\be [-\b-a\baA\bAf\bfF\bFg\bgi\biI\bIl\bln\bnr\brt\btu\bux\bx] [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ...]
t\bty\byp\bpe\bes\bse\bet\bt [-\b-a\baA\bAf\bfF\bFg\bgi\biI\bIl\bln\bnr\brt\btu\bux\bx] [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ...]
- Declare variables and/or give them attributes. If no _\bn_\ba_\bm_\bes are
- given then display the values of variables. The -\b-p\bp option will
- display the attributes and values of each _\bn_\ba_\bm_\be. When -\b-p\bp is used
- with _\bn_\ba_\bm_\be arguments, additional options, other than -\b-f\bf and -\b-F\bF,
- are ignored. When -\b-p\bp is supplied without _\bn_\ba_\bm_\be arguments, it will
- display the attributes and values of all variables having the
- attributes specified by the additional options. If no other op-
- tions are supplied with -\b-p\bp, d\bde\bec\bcl\bla\bar\bre\be will display the attributes
- and values of all shell variables. The -\b-f\bf option will restrict
- the display to shell functions. The -\b-F\bF option inhibits the dis-
- play of function definitions; only the function name and at-
- tributes are printed. If the e\bex\bxt\btd\bde\beb\bbu\bug\bg shell option is enabled
- using s\bsh\bho\bop\bpt\bt, the source file name and line number where each
- _\bn_\ba_\bm_\be is defined are displayed as well. The -\b-F\bF option implies -\b-f\bf.
- The -\b-g\bg option forces variables to be created or modified at the
- global scope, even when d\bde\bec\bcl\bla\bar\bre\be is executed in a shell function.
- It is ignored in all other cases. The -\b-I\bI option causes local
- variables to inherit the attributes (except the _\bn_\ba_\bm_\be_\br_\be_\bf attri-
- bute) and value of any existing variable with the same _\bn_\ba_\bm_\be at a
- surrounding scope. If there is no existing variable, the local
- variable is initially unset. The following options can be used
- to restrict output to variables with the specified attribute or
- to give variables attributes:
- -\b-a\ba Each _\bn_\ba_\bm_\be is an indexed array variable (see A\bAr\brr\bra\bay\bys\bs in
+ Declare variables and/or give them attributes. If no _\bn_\ba_\bm_\bes are
+ given then display the values of variables. The -\b-p\bp option will
+ display the attributes and values of each _\bn_\ba_\bm_\be. When -\b-p\bp is used
+ with _\bn_\ba_\bm_\be arguments, additional options, other than -\b-f\bf and -\b-F\bF,
+ are ignored. When -\b-p\bp is supplied without _\bn_\ba_\bm_\be arguments, it
+ will display the attributes and values of all variables having
+ the attributes specified by the additional options. If no other
+ options are supplied with -\b-p\bp, d\bde\bec\bcl\bla\bar\bre\be will display the at-
+ tributes and values of all shell variables. The -\b-f\bf option will
+ restrict the display to shell functions. The -\b-F\bF option inhibits
+ the display of function definitions; only the function name and
+ attributes are printed. If the e\bex\bxt\btd\bde\beb\bbu\bug\bg shell option is enabled
+ using s\bsh\bho\bop\bpt\bt, the source file name and line number where each
+ _\bn_\ba_\bm_\be is defined are displayed as well. The -\b-F\bF option implies
+ -\b-f\bf. The -\b-g\bg option forces variables to be created or modified at
+ the global scope, even when d\bde\bec\bcl\bla\bar\bre\be is executed in a shell func-
+ tion. It is ignored in all other cases. The -\b-I\bI option causes
+ local variables to inherit the attributes (except the _\bn_\ba_\bm_\be_\br_\be_\bf
+ attribute) and value of any existing variable with the same _\bn_\ba_\bm_\be
+ at a surrounding scope. If there is no existing variable, the
+ local variable is initially unset. The following options can be
+ used to restrict output to variables with the specified attri-
+ bute or to give variables attributes:
+ -\b-a\ba Each _\bn_\ba_\bm_\be is an indexed array variable (see A\bAr\brr\bra\bay\bys\bs in
_\bb_\ba_\bs_\bh_\b(_\b1_\b)).
-\b-A\bA Each _\bn_\ba_\bm_\be is an associative array variable (see A\bAr\brr\bra\bay\bys\bs in
_\bb_\ba_\bs_\bh_\b(_\b1_\b)).
-\b-f\bf Use function names only.
-\b-i\bi The variable is treated as an integer; arithmetic evalua-
- tion (see A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) is performed
+ tion (see A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) is performed
when the variable is assigned a value.
- -\b-l\bl When the variable is assigned a value, all upper-case
- characters are converted to lower-case. The upper-case
+ -\b-l\bl When the variable is assigned a value, all upper-case
+ characters are converted to lower-case. The upper-case
attribute is disabled.
- -\b-n\bn Give each _\bn_\ba_\bm_\be the _\bn_\ba_\bm_\be_\br_\be_\bf attribute, making it a name
- reference to another variable. That other variable is de-
- fined by the value of _\bn_\ba_\bm_\be. All references, assignments,
- and attribute modifications to _\bn_\ba_\bm_\be, except those using
- or changing the -\b-n\bn attribute itself, are performed on the
- variable referenced by _\bn_\ba_\bm_\be's value. The nameref attri-
- bute cannot be applied to array variables.
- -\b-r\br Make _\bn_\ba_\bm_\bes readonly. These names cannot then be assigned
+ -\b-n\bn Give each _\bn_\ba_\bm_\be the _\bn_\ba_\bm_\be_\br_\be_\bf attribute, making it a name
+ reference to another variable. That other variable is
+ defined by the value of _\bn_\ba_\bm_\be. All references, assign-
+ ments, and attribute modifications to _\bn_\ba_\bm_\be, except those
+ using or changing the -\b-n\bn attribute itself, are performed
+ on the variable referenced by _\bn_\ba_\bm_\be's value. The nameref
+ attribute cannot be applied to array variables.
+ -\b-r\br Make _\bn_\ba_\bm_\bes readonly. These names cannot then be assigned
values by subsequent assignment statements or unset.
- -\b-t\bt Give each _\bn_\ba_\bm_\be the _\bt_\br_\ba_\bc_\be attribute. Traced functions in-
- herit the D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN traps from the calling shell.
+ -\b-t\bt Give each _\bn_\ba_\bm_\be the _\bt_\br_\ba_\bc_\be attribute. Traced functions in-
+ herit the D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN traps from the calling shell.
The trace attribute has no special meaning for variables.
- -\b-u\bu When the variable is assigned a value, all lower-case
- characters are converted to upper-case. The lower-case
+ -\b-u\bu When the variable is assigned a value, all lower-case
+ characters are converted to upper-case. The lower-case
attribute is disabled.
- -\b-x\bx Mark _\bn_\ba_\bm_\bes for export to subsequent commands via the en-
+ -\b-x\bx Mark _\bn_\ba_\bm_\bes for export to subsequent commands via the en-
vironment.
- Using `+' instead of `-' turns off the attribute instead, with
- the exceptions that +\b+a\ba and +\b+A\bA may not be used to destroy array
- variables and +\b+r\br will not remove the readonly attribute. When
+ Using `+' instead of `-' turns off the attribute instead, with
+ the exceptions that +\b+a\ba and +\b+A\bA may not be used to destroy array
+ variables and +\b+r\br will not remove the readonly attribute. When
used in a function, d\bde\bec\bcl\bla\bar\bre\be and t\bty\byp\bpe\bes\bse\bet\bt make each _\bn_\ba_\bm_\be local, as
- with the l\blo\boc\bca\bal\bl command, unless the -\b-g\bg option is supplied. If a
- variable name is followed by =_\bv_\ba_\bl_\bu_\be, the value of the variable
- is set to _\bv_\ba_\bl_\bu_\be. When using -\b-a\ba or -\b-A\bA and the compound assignment
- syntax to create array variables, additional attributes do not
- take effect until subsequent assignments. The return value is 0
- unless an invalid option is encountered, an attempt is made to
- define a function using ``-f foo=bar'', an attempt is made to
+ with the l\blo\boc\bca\bal\bl command, unless the -\b-g\bg option is supplied. If a
+ variable name is followed by =_\bv_\ba_\bl_\bu_\be, the value of the variable
+ is set to _\bv_\ba_\bl_\bu_\be. When using -\b-a\ba or -\b-A\bA and the compound assign-
+ ment syntax to create array variables, additional attributes do
+ not take effect until subsequent assignments. The return value
+ is 0 unless an invalid option is encountered, an attempt is made
+ to define a function using ``-f foo=bar'', an attempt is made to
assign a value to a readonly variable, an attempt is made to as-
sign a value to an array variable without using the compound as-
signment syntax (see A\bAr\brr\bra\bay\bys\bs in _\bb_\ba_\bs_\bh_\b(_\b1_\b)), one of the _\bn_\ba_\bm_\be_\bs is not
- a valid shell variable name, an attempt is made to turn off
- readonly status for a readonly variable, an attempt is made to
- turn off array status for an array variable, or an attempt is
+ a valid shell variable name, an attempt is made to turn off
+ readonly status for a readonly variable, an attempt is made to
+ turn off array status for an array variable, or an attempt is
made to display a non-existent function with -\b-f\bf.
d\bdi\bir\brs\bs [\b[-\b-c\bcl\blp\bpv\bv]\b] [\b[+\b+_\bn]\b] [\b[-\b-_\bn]\b]
- Without options, displays the list of currently remembered di-
- rectories. The default display is on a single line with direc-
- tory names separated by spaces. Directories are added to the
- list with the p\bpu\bus\bsh\bhd\bd command; the p\bpo\bop\bpd\bd command removes entries
- from the list. The current directory is always the first direc-
+ Without options, displays the list of currently remembered di-
+ rectories. The default display is on a single line with direc-
+ tory names separated by spaces. Directories are added to the
+ list with the p\bpu\bus\bsh\bhd\bd command; the p\bpo\bop\bpd\bd command removes entries
+ from the list. The current directory is always the first direc-
tory in the stack.
- -\b-c\bc Clears the directory stack by deleting all of the en-
+ -\b-c\bc Clears the directory stack by deleting all of the en-
tries.
- -\b-l\bl Produces a listing using full pathnames; the default
+ -\b-l\bl Produces a listing using full pathnames; the default
listing format uses a tilde to denote the home directory.
-\b-p\bp Print the directory stack with one entry per line.
- -\b-v\bv Print the directory stack with one entry per line, pre-
+ -\b-v\bv Print the directory stack with one entry per line, pre-
fixing each entry with its index in the stack.
+\b+_\bn Displays the _\bnth entry counting from the left of the list
shown by d\bdi\bir\brs\bs when invoked without options, starting with
zero.
- -\b-_\bn Displays the _\bnth entry counting from the right of the
+ -\b-_\bn Displays the _\bnth entry counting from the right of the
list shown by d\bdi\bir\brs\bs when invoked without options, starting
with zero.
- The return value is 0 unless an invalid option is supplied or _\bn
+ The return value is 0 unless an invalid option is supplied or _\bn
indexes beyond the end of the directory stack.
d\bdi\bis\bso\bow\bwn\bn [-\b-a\bar\br] [-\b-h\bh] [_\bj_\bo_\bb_\bs_\bp_\be_\bc ... | _\bp_\bi_\bd ... ]
- Without options, remove each _\bj_\bo_\bb_\bs_\bp_\be_\bc from the table of active
- jobs. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, and neither the -\b-a\ba nor the -\b-r\br
- option is supplied, the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. If the -\b-h\bh option is
- given, each _\bj_\bo_\bb_\bs_\bp_\be_\bc is not removed from the table, but is marked
- so that S\bSI\bIG\bGH\bHU\bUP\bP is not sent to the job if the shell receives a
- S\bSI\bIG\bGH\bHU\bUP\bP. If no _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied, the -\b-a\ba option means to remove
- or mark all jobs; the -\b-r\br option without a _\bj_\bo_\bb_\bs_\bp_\be_\bc argument re-
- stricts operation to running jobs. The return value is 0 unless
- a _\bj_\bo_\bb_\bs_\bp_\be_\bc does not specify a valid job.
+ Without options, remove each _\bj_\bo_\bb_\bs_\bp_\be_\bc from the table of active
+ jobs. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, and neither the -\b-a\ba nor the -\b-r\br
+ option is supplied, the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb is used. If the -\b-h\bh option
+ is given, each _\bj_\bo_\bb_\bs_\bp_\be_\bc is not removed from the table, but is
+ marked so that S\bSI\bIG\bGH\bHU\bUP\bP is not sent to the job if the shell re-
+ ceives a S\bSI\bIG\bGH\bHU\bUP\bP. If no _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied, the -\b-a\ba option means
+ to remove or mark all jobs; the -\b-r\br option without a _\bj_\bo_\bb_\bs_\bp_\be_\bc ar-
+ gument restricts operation to running jobs. The return value is
+ 0 unless a _\bj_\bo_\bb_\bs_\bp_\be_\bc does not specify a valid job.
e\bec\bch\bho\bo [-\b-n\bne\beE\bE] [_\ba_\br_\bg ...]
- Output the _\ba_\br_\bgs, separated by spaces, followed by a newline. The
- return status is 0 unless a write error occurs. If -\b-n\bn is speci-
- fied, the trailing newline is suppressed. If the -\b-e\be option is
- given, interpretation of the following backslash-escaped charac-
- ters is enabled. The -\b-E\bE option disables the interpretation of
- these escape characters, even on systems where they are inter-
- preted by default. The x\bxp\bpg\bg_\b_e\bec\bch\bho\bo shell option may be used to dy-
- namically determine whether or not e\bec\bch\bho\bo interprets any options
- and expands these escape characters by default. e\bec\bch\bho\bo does not
- interpret -\b--\b- to mean the end of options. e\bec\bch\bho\bo interprets the
- following escape sequences:
+ Output the _\ba_\br_\bgs, separated by spaces, followed by a newline.
+ The return status is 0 unless a write error occurs. If -\b-n\bn is
+ specified, the trailing newline is suppressed. If the -\b-e\be option
+ is given, interpretation of the following backslash-escaped
+ characters is enabled. The -\b-E\bE option disables the interpreta-
+ tion of these escape characters, even on systems where they are
+ interpreted by default. The x\bxp\bpg\bg_\b_e\bec\bch\bho\bo shell option may be used
+ to dynamically determine whether or not e\bec\bch\bho\bo interprets any op-
+ tions and expands these escape characters by default. e\bec\bch\bho\bo does
+ not interpret -\b--\b- to mean the end of options. e\bec\bch\bho\bo interprets
+ the following escape sequences:
\\b\a\ba alert (bell)
\\b\b\bb backspace
\\b\c\bc suppress further output
\\b\t\bt horizontal tab
\\b\v\bv vertical tab
\\b\\\b\ backslash
- \\b\0\b0_\bn_\bn_\bn the eight-bit character whose value is the octal value
+ \\b\0\b0_\bn_\bn_\bn the eight-bit character whose value is the octal value
_\bn_\bn_\bn (zero to three octal digits)
- \\b\x\bx_\bH_\bH the eight-bit character whose value is the hexadecimal
+ \\b\x\bx_\bH_\bH the eight-bit character whose value is the hexadecimal
value _\bH_\bH (one or two hex digits)
- \\b\u\bu_\bH_\bH_\bH_\bH the Unicode (ISO/IEC 10646) character whose value is the
+ \\b\u\bu_\bH_\bH_\bH_\bH the Unicode (ISO/IEC 10646) character whose value is the
hexadecimal value _\bH_\bH_\bH_\bH (one to four hex digits)
\\b\U\bU_\bH_\bH_\bH_\bH_\bH_\bH_\bH_\bH
- the Unicode (ISO/IEC 10646) character whose value is the
+ the Unicode (ISO/IEC 10646) character whose value is the
hexadecimal value _\bH_\bH_\bH_\bH_\bH_\bH_\bH_\bH (one to eight hex digits)
e\ben\bna\bab\bbl\ble\be [-\b-a\ba] [-\b-d\bdn\bnp\bps\bs] [-\b-f\bf _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be] [_\bn_\ba_\bm_\be ...]
- Enable and disable builtin shell commands. Disabling a builtin
+ Enable and disable builtin shell commands. Disabling a builtin
allows a disk command which has the same name as a shell builtin
- to be executed without specifying a full pathname, even though
- the shell normally searches for builtins before disk commands.
- If -\b-n\bn is used, each _\bn_\ba_\bm_\be is disabled; otherwise, _\bn_\ba_\bm_\be_\bs are en-
- abled. For example, to use the t\bte\bes\bst\bt binary found via the P\bPA\bAT\bTH\bH
- instead of the shell builtin version, run ``enable -n test''.
- The -\b-f\bf option means to load the new builtin command _\bn_\ba_\bm_\be from
+ to be executed without specifying a full pathname, even though
+ the shell normally searches for builtins before disk commands.
+ If -\b-n\bn is used, each _\bn_\ba_\bm_\be is disabled; otherwise, _\bn_\ba_\bm_\be_\bs are en-
+ abled. For example, to use the t\bte\bes\bst\bt binary found via the P\bPA\bAT\bTH\bH
+ instead of the shell builtin version, run ``enable -n test''.
+ The -\b-f\bf option means to load the new builtin command _\bn_\ba_\bm_\be from
shared object _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be, on systems that support dynamic loading.
B\bBa\bas\bsh\bh will use the value of the B\bBA\bAS\bSH\bH_\b_L\bLO\bOA\bAD\bDA\bAB\bBL\bLE\bES\bS_\b_P\bPA\bAT\bTH\bH variable as a
colon-separated list of directories in which to search for _\bf_\bi_\bl_\be_\b-
- _\bn_\ba_\bm_\be. The default is system-dependent. The -\b-d\bd option will delete
- a builtin previously loaded with -\b-f\bf. If no _\bn_\ba_\bm_\be arguments are
- given, or if the -\b-p\bp option is supplied, a list of shell builtins
- is printed. With no other option arguments, the list consists of
- all enabled shell builtins. If -\b-n\bn is supplied, only disabled
- builtins are printed. If -\b-a\ba is supplied, the list printed in-
- cludes all builtins, with an indication of whether or not each
- is enabled. If -\b-s\bs is supplied, the output is restricted to the
- POSIX _\bs_\bp_\be_\bc_\bi_\ba_\bl builtins. If no options are supplied and a _\bn_\ba_\bm_\be is
- not a shell builtin, e\ben\bna\bab\bbl\ble\be will attempt to load _\bn_\ba_\bm_\be from a
- shared object named _\bn_\ba_\bm_\be, as if the command were ``enable -f
- _\bn_\ba_\bm_\be _\bn_\ba_\bm_\be . The return value is 0 unless a _\bn_\ba_\bm_\be is not a shell
- builtin or there is an error loading a new builtin from a shared
- object.
+ _\bn_\ba_\bm_\be. The default is system-dependent. The -\b-d\bd option will
+ delete a builtin previously loaded with -\b-f\bf. If no _\bn_\ba_\bm_\be argu-
+ ments are given, or if the -\b-p\bp option is supplied, a list of
+ shell builtins is printed. With no other option arguments, the
+ list consists of all enabled shell builtins. If -\b-n\bn is supplied,
+ only disabled builtins are printed. If -\b-a\ba is supplied, the list
+ printed includes all builtins, with an indication of whether or
+ not each is enabled. If -\b-s\bs is supplied, the output is re-
+ stricted to the POSIX _\bs_\bp_\be_\bc_\bi_\ba_\bl builtins. If no options are sup-
+ plied and a _\bn_\ba_\bm_\be is not a shell builtin, e\ben\bna\bab\bbl\ble\be will attempt to
+ load _\bn_\ba_\bm_\be from a shared object named _\bn_\ba_\bm_\be, as if the command
+ were ``enable -f _\bn_\ba_\bm_\be _\bn_\ba_\bm_\be . The return value is 0 unless a
+ _\bn_\ba_\bm_\be is not a shell builtin or there is an error loading a new
+ builtin from a shared object.
e\bev\bva\bal\bl [_\ba_\br_\bg ...]
- The _\ba_\br_\bgs are read and concatenated together into a single com-
- mand. This command is then read and executed by the shell, and
- its exit status is returned as the value of e\bev\bva\bal\bl. If there are
+ The _\ba_\br_\bgs are read and concatenated together into a single com-
+ mand. This command is then read and executed by the shell, and
+ its exit status is returned as the value of e\bev\bva\bal\bl. If there are
no _\ba_\br_\bg_\bs, or only null arguments, e\bev\bva\bal\bl returns 0.
e\bex\bxe\bec\bc [-\b-c\bcl\bl] [-\b-a\ba _\bn_\ba_\bm_\be] [_\bc_\bo_\bm_\bm_\ba_\bn_\bd [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]]
- If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is specified, it replaces the shell. No new process
- is created. The _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs become the arguments to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. If
+ If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is specified, it replaces the shell. No new process
+ is created. The _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs become the arguments to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. If
the -\b-l\bl option is supplied, the shell places a dash at the begin-
- ning of the zeroth argument passed to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. This is what _\bl_\bo_\b-
- _\bg_\bi_\bn(1) does. The -\b-c\bc option causes _\bc_\bo_\bm_\bm_\ba_\bn_\bd to be executed with an
- empty environment. If -\b-a\ba is supplied, the shell passes _\bn_\ba_\bm_\be as
- the zeroth argument to the executed command. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd cannot
- be executed for some reason, a non-interactive shell exits, un-
- less the e\bex\bxe\bec\bcf\bfa\bai\bil\bl shell option is enabled. In that case, it re-
- turns failure. An interactive shell returns failure if the file
- cannot be executed. A subshell exits unconditionally if e\bex\bxe\bec\bc
- fails. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is not specified, any redirections take effect
- in the current shell, and the return status is 0. If there is a
- redirection error, the return status is 1.
+ ning of the zeroth argument passed to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. This is what _\bl_\bo_\b-
+ _\bg_\bi_\bn(1) does. The -\b-c\bc option causes _\bc_\bo_\bm_\bm_\ba_\bn_\bd to be executed with
+ an empty environment. If -\b-a\ba is supplied, the shell passes _\bn_\ba_\bm_\be
+ as the zeroth argument to the executed command. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd can-
+ not be executed for some reason, a non-interactive shell exits,
+ unless the e\bex\bxe\bec\bcf\bfa\bai\bil\bl shell option is enabled. In that case, it
+ returns failure. An interactive shell returns failure if the
+ file cannot be executed. A subshell exits unconditionally if
+ e\bex\bxe\bec\bc fails. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is not specified, any redirections take
+ effect in the current shell, and the return status is 0. If
+ there is a redirection error, the return status is 1.
e\bex\bxi\bit\bt [_\bn]
- Cause the shell to exit with a status of _\bn. If _\bn is omitted, the
- exit status is that of the last command executed. A trap on E\bEX\bXI\bIT\bT
- is executed before the shell terminates.
+ Cause the shell to exit with a status of _\bn. If _\bn is omitted,
+ the exit status is that of the last command executed. A trap on
+ E\bEX\bXI\bIT\bT is executed before the shell terminates.
e\bex\bxp\bpo\bor\brt\bt [-\b-f\bfn\bn] [_\bn_\ba_\bm_\be[=_\bw_\bo_\br_\bd]] ...
e\bex\bxp\bpo\bor\brt\bt -\b-p\bp
- The supplied _\bn_\ba_\bm_\be_\bs are marked for automatic export to the envi-
- ronment of subsequently executed commands. If the -\b-f\bf option is
- given, the _\bn_\ba_\bm_\be_\bs refer to functions. If no _\bn_\ba_\bm_\be_\bs are given, or
- if the -\b-p\bp option is supplied, a list of names of all exported
- variables is printed. The -\b-n\bn option causes the export property
- to be removed from each _\bn_\ba_\bm_\be. If a variable name is followed by
- =_\bw_\bo_\br_\bd, the value of the variable is set to _\bw_\bo_\br_\bd. e\bex\bxp\bpo\bor\brt\bt returns
+ The supplied _\bn_\ba_\bm_\be_\bs are marked for automatic export to the envi-
+ ronment of subsequently executed commands. If the -\b-f\bf option is
+ given, the _\bn_\ba_\bm_\be_\bs refer to functions. If no _\bn_\ba_\bm_\be_\bs are given, or
+ if the -\b-p\bp option is supplied, a list of names of all exported
+ variables is printed. The -\b-n\bn option causes the export property
+ to be removed from each _\bn_\ba_\bm_\be. If a variable name is followed by
+ =_\bw_\bo_\br_\bd, the value of the variable is set to _\bw_\bo_\br_\bd. e\bex\bxp\bpo\bor\brt\bt returns
an exit status of 0 unless an invalid option is encountered, one
- of the _\bn_\ba_\bm_\be_\bs is not a valid shell variable name, or -\b-f\bf is sup-
+ of the _\bn_\ba_\bm_\be_\bs is not a valid shell variable name, or -\b-f\bf is sup-
plied with a _\bn_\ba_\bm_\be that is not a function.
f\bfa\bal\bls\bse\be Does nothing, returns a non-zero status.
f\bfc\bc [-\b-e\be _\be_\bn_\ba_\bm_\be] [-\b-l\bln\bnr\br] [_\bf_\bi_\br_\bs_\bt] [_\bl_\ba_\bs_\bt]
f\bfc\bc -\b-s\bs [_\bp_\ba_\bt=_\br_\be_\bp] [_\bc_\bm_\bd]
- The first form selects a range of commands from _\bf_\bi_\br_\bs_\bt to _\bl_\ba_\bs_\bt
- from the history list and displays or edits and re-executes
- them. _\bF_\bi_\br_\bs_\bt and _\bl_\ba_\bs_\bt may be specified as a string (to locate the
- last command beginning with that string) or as a number (an in-
- dex into the history list, where a negative number is used as an
- offset from the current command number). When listing, a _\bf_\bi_\br_\bs_\bt
- or _\bl_\ba_\bs_\bt of 0 is equivalent to -1 and -0 is equivalent to the
- current command (usually the f\bfc\bc command); otherwise 0 is equiva-
- lent to -1 and -0 is invalid. If _\bl_\ba_\bs_\bt is not specified, it is
- set to the current command for listing (so that ``fc -l -10''
- prints the last 10 commands) and to _\bf_\bi_\br_\bs_\bt otherwise. If _\bf_\bi_\br_\bs_\bt is
- not specified, it is set to the previous command for editing and
- -16 for listing.
-
- The -\b-n\bn option suppresses the command numbers when listing. The
- -\b-r\br option reverses the order of the commands. If the -\b-l\bl option
- is given, the commands are listed on standard output. Otherwise,
- the editor given by _\be_\bn_\ba_\bm_\be is invoked on a file containing those
- commands. If _\be_\bn_\ba_\bm_\be is not given, the value of the F\bFC\bCE\bED\bDI\bIT\bT vari-
- able is used, and the value of E\bED\bDI\bIT\bTO\bOR\bR if F\bFC\bCE\bED\bDI\bIT\bT is not set. If
- neither variable is set, _\bv_\bi is used. When editing is complete,
- the edited commands are echoed and executed.
-
- In the second form, _\bc_\bo_\bm_\bm_\ba_\bn_\bd is re-executed after each instance
- of _\bp_\ba_\bt is replaced by _\br_\be_\bp. _\bC_\bo_\bm_\bm_\ba_\bn_\bd is interpreted the same as
- _\bf_\bi_\br_\bs_\bt above. A useful alias to use with this is ``r="fc -s"'',
- so that typing ``r cc'' runs the last command beginning with
+ The first form selects a range of commands from _\bf_\bi_\br_\bs_\bt to _\bl_\ba_\bs_\bt
+ from the history list and displays or edits and re-executes
+ them. _\bF_\bi_\br_\bs_\bt and _\bl_\ba_\bs_\bt may be specified as a string (to locate
+ the last command beginning with that string) or as a number (an
+ index into the history list, where a negative number is used as
+ an offset from the current command number). When listing, a
+ _\bf_\bi_\br_\bs_\bt or _\bl_\ba_\bs_\bt of 0 is equivalent to -1 and -0 is equivalent to
+ the current command (usually the f\bfc\bc command); otherwise 0 is
+ equivalent to -1 and -0 is invalid. If _\bl_\ba_\bs_\bt is not specified,
+ it is set to the current command for listing (so that ``fc -l
+ -10'' prints the last 10 commands) and to _\bf_\bi_\br_\bs_\bt otherwise. If
+ _\bf_\bi_\br_\bs_\bt is not specified, it is set to the previous command for
+ editing and -16 for listing.
+
+ The -\b-n\bn option suppresses the command numbers when listing. The
+ -\b-r\br option reverses the order of the commands. If the -\b-l\bl option
+ is given, the commands are listed on standard output. Other-
+ wise, the editor given by _\be_\bn_\ba_\bm_\be is invoked on a file containing
+ those commands. If _\be_\bn_\ba_\bm_\be is not given, the value of the F\bFC\bCE\bED\bDI\bIT\bT
+ variable is used, and the value of E\bED\bDI\bIT\bTO\bOR\bR if F\bFC\bCE\bED\bDI\bIT\bT is not set.
+ If neither variable is set, _\bv_\bi is used. When editing is com-
+ plete, the edited commands are echoed and executed.
+
+ In the second form, _\bc_\bo_\bm_\bm_\ba_\bn_\bd is re-executed after each instance
+ of _\bp_\ba_\bt is replaced by _\br_\be_\bp. _\bC_\bo_\bm_\bm_\ba_\bn_\bd is interpreted the same as
+ _\bf_\bi_\br_\bs_\bt above. A useful alias to use with this is ``r="fc -s"'',
+ so that typing ``r cc'' runs the last command beginning with
``cc'' and typing ``r'' re-executes the last command.
- If the first form is used, the return value is 0 unless an in-
- valid option is encountered or _\bf_\bi_\br_\bs_\bt or _\bl_\ba_\bs_\bt specify history
- lines out of range. If the -\b-e\be option is supplied, the return
+ If the first form is used, the return value is 0 unless an in-
+ valid option is encountered or _\bf_\bi_\br_\bs_\bt or _\bl_\ba_\bs_\bt specify history
+ lines out of range. If the -\b-e\be option is supplied, the return
value is the value of the last command executed or failure if an
- error occurs with the temporary file of commands. If the second
- form is used, the return status is that of the command re-exe-
- cuted, unless _\bc_\bm_\bd does not specify a valid history line, in
+ error occurs with the temporary file of commands. If the second
+ form is used, the return status is that of the command re-exe-
+ cuted, unless _\bc_\bm_\bd does not specify a valid history line, in
which case f\bfc\bc returns failure.
f\bfg\bg [_\bj_\bo_\bb_\bs_\bp_\be_\bc]
- Resume _\bj_\bo_\bb_\bs_\bp_\be_\bc in the foreground, and make it the current job.
+ Resume _\bj_\bo_\bb_\bs_\bp_\be_\bc in the foreground, and make it the current job.
If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, the shell's notion of the _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb
- is used. The return value is that of the command placed into the
- foreground, or failure if run when job control is disabled or,
- when run with job control enabled, if _\bj_\bo_\bb_\bs_\bp_\be_\bc does not specify a
- valid job or _\bj_\bo_\bb_\bs_\bp_\be_\bc specifies a job that was started without
- job control.
+ is used. The return value is that of the command placed into
+ the foreground, or failure if run when job control is disabled
+ or, when run with job control enabled, if _\bj_\bo_\bb_\bs_\bp_\be_\bc does not spec-
+ ify a valid job or _\bj_\bo_\bb_\bs_\bp_\be_\bc specifies a job that was started
+ without job control.
g\bge\bet\bto\bop\bpt\bts\bs _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg _\bn_\ba_\bm_\be [_\ba_\br_\bg _\b._\b._\b.]
- g\bge\bet\bto\bop\bpt\bts\bs is used by shell procedures to parse positional parame-
- ters. _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg contains the option characters to be recognized;
- if a character is followed by a colon, the option is expected to
- have an argument, which should be separated from it by white
- space. The colon and question mark characters may not be used as
- option characters. Each time it is invoked, g\bge\bet\bto\bop\bpt\bts\bs places the
- next option in the shell variable _\bn_\ba_\bm_\be, initializing _\bn_\ba_\bm_\be if it
- does not exist, and the index of the next argument to be pro-
- cessed into the variable O\bOP\bPT\bTI\bIN\bND\bD. O\bOP\bPT\bTI\bIN\bND\bD is initialized to 1 each
- time the shell or a shell script is invoked. When an option re-
- quires an argument, g\bge\bet\bto\bop\bpt\bts\bs places that argument into the vari-
- able O\bOP\bPT\bTA\bAR\bRG\bG. The shell does not reset O\bOP\bPT\bTI\bIN\bND\bD automatically; it
- must be manually reset between multiple calls to g\bge\bet\bto\bop\bpt\bts\bs within
- the same shell invocation if a new set of parameters is to be
- used.
+ g\bge\bet\bto\bop\bpt\bts\bs is used by shell procedures to parse positional parame-
+ ters. _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg contains the option characters to be recog-
+ nized; if a character is followed by a colon, the option is ex-
+ pected to have an argument, which should be separated from it by
+ white space. The colon and question mark characters may not be
+ used as option characters. Each time it is invoked, g\bge\bet\bto\bop\bpt\bts\bs
+ places the next option in the shell variable _\bn_\ba_\bm_\be, initializing
+ _\bn_\ba_\bm_\be if it does not exist, and the index of the next argument to
+ be processed into the variable O\bOP\bPT\bTI\bIN\bND\bD. O\bOP\bPT\bTI\bIN\bND\bD is initialized to
+ 1 each time the shell or a shell script is invoked. When an op-
+ tion requires an argument, g\bge\bet\bto\bop\bpt\bts\bs places that argument into the
+ variable O\bOP\bPT\bTA\bAR\bRG\bG. The shell does not reset O\bOP\bPT\bTI\bIN\bND\bD automatically;
+ it must be manually reset between multiple calls to g\bge\bet\bto\bop\bpt\bts\bs
+ within the same shell invocation if a new set of parameters is
+ to be used.
When the end of options is encountered, g\bge\bet\bto\bop\bpt\bts\bs exits with a re-
- turn value greater than zero. O\bOP\bPT\bTI\bIN\bND\bD is set to the index of the
+ turn value greater than zero. O\bOP\bPT\bTI\bIN\bND\bD is set to the index of the
first non-option argument, and _\bn_\ba_\bm_\be is set to ?.
- g\bge\bet\bto\bop\bpt\bts\bs normally parses the positional parameters, but if more
- arguments are supplied as _\ba_\br_\bg values, g\bge\bet\bto\bop\bpt\bts\bs parses those in-
+ g\bge\bet\bto\bop\bpt\bts\bs normally parses the positional parameters, but if more
+ arguments are supplied as _\ba_\br_\bg values, g\bge\bet\bto\bop\bpt\bts\bs parses those in-
stead.
- g\bge\bet\bto\bop\bpt\bts\bs can report errors in two ways. If the first character of
- _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is a colon, _\bs_\bi_\bl_\be_\bn_\bt error reporting is used. In normal
- operation, diagnostic messages are printed when invalid options
- or missing option arguments are encountered. If the variable
- O\bOP\bPT\bTE\bER\bRR\bR is set to 0, no error messages will be displayed, even if
- the first character of _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is not a colon.
+ g\bge\bet\bto\bop\bpt\bts\bs can report errors in two ways. If the first character
+ of _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is a colon, _\bs_\bi_\bl_\be_\bn_\bt error reporting is used. In
+ normal operation, diagnostic messages are printed when invalid
+ options or missing option arguments are encountered. If the
+ variable O\bOP\bPT\bTE\bER\bRR\bR is set to 0, no error messages will be dis-
+ played, even if the first character of _\bo_\bp_\bt_\bs_\bt_\br_\bi_\bn_\bg is not a colon.
If an invalid option is seen, g\bge\bet\bto\bop\bpt\bts\bs places ? into _\bn_\ba_\bm_\be and, if
- not silent, prints an error message and unsets O\bOP\bPT\bTA\bAR\bRG\bG. If
- g\bge\bet\bto\bop\bpt\bts\bs is silent, the option character found is placed in O\bOP\bP-\b-
+ not silent, prints an error message and unsets O\bOP\bPT\bTA\bAR\bRG\bG. If
+ g\bge\bet\bto\bop\bpt\bts\bs is silent, the option character found is placed in O\bOP\bP-\b-
T\bTA\bAR\bRG\bG and no diagnostic message is printed.
- If a required argument is not found, and g\bge\bet\bto\bop\bpt\bts\bs is not silent,
- a question mark (?\b?) is placed in _\bn_\ba_\bm_\be, O\bOP\bPT\bTA\bAR\bRG\bG is unset, and a
- diagnostic message is printed. If g\bge\bet\bto\bop\bpt\bts\bs is silent, then a
- colon (:\b:) is placed in _\bn_\ba_\bm_\be and O\bOP\bPT\bTA\bAR\bRG\bG is set to the option
+ If a required argument is not found, and g\bge\bet\bto\bop\bpt\bts\bs is not silent,
+ a question mark (?\b?) is placed in _\bn_\ba_\bm_\be, O\bOP\bPT\bTA\bAR\bRG\bG is unset, and a
+ diagnostic message is printed. If g\bge\bet\bto\bop\bpt\bts\bs is silent, then a
+ colon (:\b:) is placed in _\bn_\ba_\bm_\be and O\bOP\bPT\bTA\bAR\bRG\bG is set to the option
character found.
- g\bge\bet\bto\bop\bpt\bts\bs returns true if an option, specified or unspecified, is
+ g\bge\bet\bto\bop\bpt\bts\bs returns true if an option, specified or unspecified, is
found. It returns false if the end of options is encountered or
an error occurs.
h\bha\bas\bsh\bh [-\b-l\blr\br] [-\b-p\bp _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be] [-\b-d\bdt\bt] [_\bn_\ba_\bm_\be]
Each time h\bha\bas\bsh\bh is invoked, the full pathname of the command _\bn_\ba_\bm_\be
- is determined by searching the directories in $\b$P\bPA\bAT\bTH\bH and remem-
- bered. Any previously-remembered pathname is discarded. If the
- -\b-p\bp option is supplied, h\bha\bas\bsh\bh uses _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be as the full filename
- of the command. The -\b-r\br option causes the shell to forget all re-
- membered locations. Assigning to the P\bPA\bAT\bTH\bH variable also clears
- all hashed filenames. The -\b-d\bd option causes the shell to forget
- the remembered location of each _\bn_\ba_\bm_\be. If the -\b-t\bt option is sup-
- plied, the full pathname to which each _\bn_\ba_\bm_\be corresponds is
- printed. If multiple _\bn_\ba_\bm_\be arguments are supplied with -\b-t\bt, the
- _\bn_\ba_\bm_\be is printed before the hashed full pathname. The -\b-l\bl option
- causes output to be displayed in a format that may be reused as
- input. If no arguments are given, or if only -\b-l\bl is supplied, in-
- formation about remembered commands is printed. The -\b-t\bt, -\b-d\bd, and
- -\b-p\bp options (the options that act on the _\bn_\ba_\bm_\be arguments) are mu-
- tually exclusive. Only one will be active. If more than one is
- supplied, -\b-t\bt has higher priority than -\b-p\bp, and both are higher
- priority than -\b-d\bd. The return status is true unless a _\bn_\ba_\bm_\be is not
- found or an invalid option is supplied.
+ is determined by searching the directories in $\b$P\bPA\bAT\bTH\bH and remem-
+ bered. Any previously-remembered pathname is discarded. If the
+ -\b-p\bp option is supplied, h\bha\bas\bsh\bh uses _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be as the full filename
+ of the command. The -\b-r\br option causes the shell to forget all
+ remembered locations. Assigning to the P\bPA\bAT\bTH\bH variable also
+ clears all hashed filenames. The -\b-d\bd option causes the shell to
+ forget the remembered location of each _\bn_\ba_\bm_\be. If the -\b-t\bt option
+ is supplied, the full pathname to which each _\bn_\ba_\bm_\be corresponds is
+ printed. If multiple _\bn_\ba_\bm_\be arguments are supplied with -\b-t\bt, the
+ _\bn_\ba_\bm_\be is printed before the hashed full pathname. The -\b-l\bl option
+ causes output to be displayed in a format that may be reused as
+ input. If no arguments are given, or if only -\b-l\bl is supplied,
+ information about remembered commands is printed. The -\b-t\bt, -\b-d\bd,
+ and -\b-p\bp options (the options that act on the _\bn_\ba_\bm_\be arguments) are
+ mutually exclusive. Only one will be active. If more than one
+ is supplied, -\b-t\bt has higher priority than -\b-p\bp, and both are higher
+ priority than -\b-d\bd. The return status is true unless a _\bn_\ba_\bm_\be is
+ not found or an invalid option is supplied.
h\bhe\bel\blp\bp [-\b-d\bdm\bms\bs] [_\bp_\ba_\bt_\bt_\be_\br_\bn]
- Display helpful information about builtin commands. If _\bp_\ba_\bt_\bt_\be_\br_\bn
- is specified, h\bhe\bel\blp\bp gives detailed help on all commands matching
- _\bp_\ba_\bt_\bt_\be_\br_\bn; otherwise help for all the builtins and shell control
+ Display helpful information about builtin commands. If _\bp_\ba_\bt_\bt_\be_\br_\bn
+ is specified, h\bhe\bel\blp\bp gives detailed help on all commands matching
+ _\bp_\ba_\bt_\bt_\be_\br_\bn; otherwise help for all the builtins and shell control
structures is printed.
-\b-d\bd Display a short description of each _\bp_\ba_\bt_\bt_\be_\br_\bn
-\b-m\bm Display the description of each _\bp_\ba_\bt_\bt_\be_\br_\bn in a manpage-like
h\bhi\bis\bst\bto\bor\bry\by -\b-p\bp _\ba_\br_\bg [_\ba_\br_\bg _\b._\b._\b.]
h\bhi\bis\bst\bto\bor\bry\by -\b-s\bs _\ba_\br_\bg [_\ba_\br_\bg _\b._\b._\b.]
With no options, display the command history list with line num-
- bers. Lines listed with a *\b* have been modified. An argument of _\bn
- lists only the last _\bn lines. If the shell variable H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bR-\b-
- M\bMA\bAT\bT is set and not null, it is used as a format string for _\bs_\bt_\br_\bf_\b-
- _\bt_\bi_\bm_\be(3) to display the time stamp associated with each displayed
- history entry. No intervening blank is printed between the for-
- matted time stamp and the history line. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is supplied,
- it is used as the name of the history file; if not, the value of
- H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is used. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is not supplied and H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is
- unset or null, the -\b-a\ba,\b, -\b-n\bn,\b, -\b-r\br,\b, and -\b-w\bw options have no effect.
- Options, if supplied, have the following meanings:
+ bers. Lines listed with a *\b* have been modified. An argument of
+ _\bn lists only the last _\bn lines. If the shell variable H\bHI\bIS\bST\bTT\bTI\bIM\bME\bE-\b-
+ F\bFO\bOR\bRM\bMA\bAT\bT is set and not null, it is used as a format string for
+ _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3) to display the time stamp associated with each dis-
+ played history entry. No intervening blank is printed between
+ the formatted time stamp and the history line. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is
+ supplied, it is used as the name of the history file; if not,
+ the value of H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is used. If _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is not supplied and
+ H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is unset or null, the -\b-a\ba,\b, -\b-n\bn,\b, -\b-r\br,\b, and -\b-w\bw options have
+ no effect. Options, if supplied, have the following meanings:
-\b-c\bc Clear the history list by deleting all the entries.
-\b-d\bd _\bo_\bf_\bf_\bs_\be_\bt
- Delete the history entry at position _\bo_\bf_\bf_\bs_\be_\bt. If _\bo_\bf_\bf_\bs_\be_\bt is
- negative, it is interpreted as relative to one greater
+ Delete the history entry at position _\bo_\bf_\bf_\bs_\be_\bt. If _\bo_\bf_\bf_\bs_\be_\bt
+ is negative, it is interpreted as relative to one greater
than the last history position, so negative indices count
- back from the end of the history, and an index of -1
+ back from the end of the history, and an index of -1
refers to the current h\bhi\bis\bst\bto\bor\bry\by -\b-d\bd command.
-\b-d\bd _\bs_\bt_\ba_\br_\bt-_\be_\bn_\bd
- Delete the range of history entries between positions
- _\bs_\bt_\ba_\br_\bt and _\be_\bn_\bd, inclusive. Positive and negative values
+ Delete the range of history entries between positions
+ _\bs_\bt_\ba_\br_\bt and _\be_\bn_\bd, inclusive. Positive and negative values
for _\bs_\bt_\ba_\br_\bt and _\be_\bn_\bd are interpreted as described above.
- -\b-a\ba Append the ``new'' history lines to the history file.
- These are history lines entered since the beginning of
+ -\b-a\ba Append the ``new'' history lines to the history file.
+ These are history lines entered since the beginning of
the current b\bba\bas\bsh\bh session, but not already appended to the
history file.
- -\b-n\bn Read the history lines not already read from the history
- file into the current history list. These are lines ap-
- pended to the history file since the beginning of the
+ -\b-n\bn Read the history lines not already read from the history
+ file into the current history list. These are lines ap-
+ pended to the history file since the beginning of the
current b\bba\bas\bsh\bh session.
- -\b-r\br Read the contents of the history file and append them to
+ -\b-r\br Read the contents of the history file and append them to
the current history list.
-\b-w\bw Write the current history list to the history file, over-
writing the history file's contents.
- -\b-p\bp Perform history substitution on the following _\ba_\br_\bg_\bs and
- display the result on the standard output. Does not store
- the results in the history list. Each _\ba_\br_\bg must be quoted
- to disable normal history expansion.
- -\b-s\bs Store the _\ba_\br_\bg_\bs in the history list as a single entry. The
- last command in the history list is removed before the
- _\ba_\br_\bg_\bs are added.
-
- If the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable is set, the time stamp informa-
- tion associated with each history entry is written to the his-
- tory file, marked with the history comment character. When the
- history file is read, lines beginning with the history comment
- character followed immediately by a digit are interpreted as
- timestamps for the following history entry. The return value is
+ -\b-p\bp Perform history substitution on the following _\ba_\br_\bg_\bs and
+ display the result on the standard output. Does not
+ store the results in the history list. Each _\ba_\br_\bg must be
+ quoted to disable normal history expansion.
+ -\b-s\bs Store the _\ba_\br_\bg_\bs in the history list as a single entry.
+ The last command in the history list is removed before
+ the _\ba_\br_\bg_\bs are added.
+
+ If the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable is set, the time stamp informa-
+ tion associated with each history entry is written to the his-
+ tory file, marked with the history comment character. When the
+ history file is read, lines beginning with the history comment
+ character followed immediately by a digit are interpreted as
+ timestamps for the following history entry. The return value is
0 unless an invalid option is encountered, an error occurs while
- reading or writing the history file, an invalid _\bo_\bf_\bf_\bs_\be_\bt or range
- is supplied as an argument to -\b-d\bd, or the history expansion sup-
+ reading or writing the history file, an invalid _\bo_\bf_\bf_\bs_\be_\bt or range
+ is supplied as an argument to -\b-d\bd, or the history expansion sup-
plied as an argument to -\b-p\bp fails.
j\bjo\bob\bbs\bs [-\b-l\bln\bnp\bpr\brs\bs] [ _\bj_\bo_\bb_\bs_\bp_\be_\bc ... ]
j\bjo\bob\bbs\bs -\b-x\bx _\bc_\bo_\bm_\bm_\ba_\bn_\bd [ _\ba_\br_\bg_\bs ... ]
- The first form lists the active jobs. The options have the fol-
+ The first form lists the active jobs. The options have the fol-
lowing meanings:
-\b-l\bl List process IDs in addition to the normal information.
- -\b-n\bn Display information only about jobs that have changed
+ -\b-n\bn Display information only about jobs that have changed
status since the user was last notified of their status.
- -\b-p\bp List only the process ID of the job's process group
+ -\b-p\bp List only the process ID of the job's process group
leader.
-\b-r\br Display only running jobs.
-\b-s\bs Display only stopped jobs.
- If _\bj_\bo_\bb_\bs_\bp_\be_\bc is given, output is restricted to information about
- that job. The return status is 0 unless an invalid option is en-
- countered or an invalid _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied.
+ If _\bj_\bo_\bb_\bs_\bp_\be_\bc is given, output is restricted to information about
+ that job. The return status is 0 unless an invalid option is
+ encountered or an invalid _\bj_\bo_\bb_\bs_\bp_\be_\bc is supplied.
If the -\b-x\bx option is supplied, j\bjo\bob\bbs\bs replaces any _\bj_\bo_\bb_\bs_\bp_\be_\bc found in
_\bc_\bo_\bm_\bm_\ba_\bn_\bd or _\ba_\br_\bg_\bs with the corresponding process group ID, and ex-
k\bki\bil\bll\bl [-\b-s\bs _\bs_\bi_\bg_\bs_\bp_\be_\bc | -\b-n\bn _\bs_\bi_\bg_\bn_\bu_\bm | -\b-_\bs_\bi_\bg_\bs_\bp_\be_\bc] [_\bp_\bi_\bd | _\bj_\bo_\bb_\bs_\bp_\be_\bc] ...
k\bki\bil\bll\bl -\b-l\bl|-\b-L\bL [_\bs_\bi_\bg_\bs_\bp_\be_\bc | _\be_\bx_\bi_\bt_\b__\bs_\bt_\ba_\bt_\bu_\bs]
- Send the signal named by _\bs_\bi_\bg_\bs_\bp_\be_\bc or _\bs_\bi_\bg_\bn_\bu_\bm to the processes
- named by _\bp_\bi_\bd or _\bj_\bo_\bb_\bs_\bp_\be_\bc. _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a case-insensitive
- signal name such as S\bSI\bIG\bGK\bKI\bIL\bLL\bL (with or without the S\bSI\bIG\bG prefix) or
- a signal number; _\bs_\bi_\bg_\bn_\bu_\bm is a signal number. If _\bs_\bi_\bg_\bs_\bp_\be_\bc is not
- present, then S\bSI\bIG\bGT\bTE\bER\bRM\bM is assumed. An argument of -\b-l\bl lists the
- signal names. If any arguments are supplied when -\b-l\bl is given,
- the names of the signals corresponding to the arguments are
- listed, and the return status is 0. The _\be_\bx_\bi_\bt_\b__\bs_\bt_\ba_\bt_\bu_\bs argument to
- -\b-l\bl is a number specifying either a signal number or the exit
- status of a process terminated by a signal. The -\b-L\bL option is
- equivalent to -\b-l\bl. k\bki\bil\bll\bl returns true if at least one signal was
+ Send the signal named by _\bs_\bi_\bg_\bs_\bp_\be_\bc or _\bs_\bi_\bg_\bn_\bu_\bm to the processes
+ named by _\bp_\bi_\bd or _\bj_\bo_\bb_\bs_\bp_\be_\bc. _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a case-insensitive
+ signal name such as S\bSI\bIG\bGK\bKI\bIL\bLL\bL (with or without the S\bSI\bIG\bG prefix) or
+ a signal number; _\bs_\bi_\bg_\bn_\bu_\bm is a signal number. If _\bs_\bi_\bg_\bs_\bp_\be_\bc is not
+ present, then S\bSI\bIG\bGT\bTE\bER\bRM\bM is assumed. An argument of -\b-l\bl lists the
+ signal names. If any arguments are supplied when -\b-l\bl is given,
+ the names of the signals corresponding to the arguments are
+ listed, and the return status is 0. The _\be_\bx_\bi_\bt_\b__\bs_\bt_\ba_\bt_\bu_\bs argument to
+ -\b-l\bl is a number specifying either a signal number or the exit
+ status of a process terminated by a signal. The -\b-L\bL option is
+ equivalent to -\b-l\bl. k\bki\bil\bll\bl returns true if at least one signal was
successfully sent, or false if an error occurs or an invalid op-
tion is encountered.
l\ble\bet\bt _\ba_\br_\bg [_\ba_\br_\bg ...]
Each _\ba_\br_\bg is an arithmetic expression to be evaluated (see A\bAR\bRI\bIT\bTH\bH-\b-
- M\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). If the last _\ba_\br_\bg evaluates to 0,
+ M\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). If the last _\ba_\br_\bg evaluates to 0,
l\ble\bet\bt returns 1; 0 is returned otherwise.
l\blo\boc\bca\bal\bl [_\bo_\bp_\bt_\bi_\bo_\bn] [_\bn_\ba_\bm_\be[=_\bv_\ba_\bl_\bu_\be] ... | - ]
- For each argument, a local variable named _\bn_\ba_\bm_\be is created, and
- assigned _\bv_\ba_\bl_\bu_\be. The _\bo_\bp_\bt_\bi_\bo_\bn can be any of the options accepted by
- d\bde\bec\bcl\bla\bar\bre\be. When l\blo\boc\bca\bal\bl is used within a function, it causes the
- variable _\bn_\ba_\bm_\be to have a visible scope restricted to that func-
- tion and its children. If _\bn_\ba_\bm_\be is -, the set of shell options is
- made local to the function in which l\blo\boc\bca\bal\bl is invoked: shell op-
- tions changed using the s\bse\bet\bt builtin inside the function after
+ For each argument, a local variable named _\bn_\ba_\bm_\be is created, and
+ assigned _\bv_\ba_\bl_\bu_\be. The _\bo_\bp_\bt_\bi_\bo_\bn can be any of the options accepted
+ by d\bde\bec\bcl\bla\bar\bre\be. When l\blo\boc\bca\bal\bl is used within a function, it causes the
+ variable _\bn_\ba_\bm_\be to have a visible scope restricted to that func-
+ tion and its children. If _\bn_\ba_\bm_\be is -, the set of shell options
+ is made local to the function in which l\blo\boc\bca\bal\bl is invoked: shell
+ options changed using the s\bse\bet\bt builtin inside the function after
the call to l\blo\boc\bca\bal\bl are restored to their original values when the
- function returns. The restore is effected as if a series of s\bse\bet\bt
- commands were executed to restore the values that were in place
- before the function. With no operands, l\blo\boc\bca\bal\bl writes a list of
- local variables to the standard output. It is an error to use
- l\blo\boc\bca\bal\bl when not within a function. The return status is 0 unless
- l\blo\boc\bca\bal\bl is used outside a function, an invalid _\bn_\ba_\bm_\be is supplied,
+ function returns. The restore is effected as if a series of s\bse\bet\bt
+ commands were executed to restore the values that were in place
+ before the function. With no operands, l\blo\boc\bca\bal\bl writes a list of
+ local variables to the standard output. It is an error to use
+ l\blo\boc\bca\bal\bl when not within a function. The return status is 0 unless
+ l\blo\boc\bca\bal\bl is used outside a function, an invalid _\bn_\ba_\bm_\be is supplied,
or _\bn_\ba_\bm_\be is a readonly variable.
l\blo\bog\bgo\bou\but\bt Exit a login shell.
- m\bma\bap\bpf\bfi\bil\ble\be [-\b-d\bd _\bd_\be_\bl_\bi_\bm] [-\b-n\bn _\bc_\bo_\bu_\bn_\bt] [-\b-O\bO _\bo_\br_\bi_\bg_\bi_\bn] [-\b-s\bs _\bc_\bo_\bu_\bn_\bt] [-\b-t\bt] [-\b-u\bu _\bf_\bd] [-\b-C\bC
+ m\bma\bap\bpf\bfi\bil\ble\be [-\b-d\bd _\bd_\be_\bl_\bi_\bm] [-\b-n\bn _\bc_\bo_\bu_\bn_\bt] [-\b-O\bO _\bo_\br_\bi_\bg_\bi_\bn] [-\b-s\bs _\bc_\bo_\bu_\bn_\bt] [-\b-t\bt] [-\b-u\bu _\bf_\bd] [-\b-C\bC
_\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk] [-\b-c\bc _\bq_\bu_\ba_\bn_\bt_\bu_\bm] [_\ba_\br_\br_\ba_\by]
r\bre\bea\bad\bda\bar\brr\bra\bay\by [-\b-d\bd _\bd_\be_\bl_\bi_\bm] [-\b-n\bn _\bc_\bo_\bu_\bn_\bt] [-\b-O\bO _\bo_\br_\bi_\bg_\bi_\bn] [-\b-s\bs _\bc_\bo_\bu_\bn_\bt] [-\b-t\bt] [-\b-u\bu _\bf_\bd] [-\b-C\bC
_\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk] [-\b-c\bc _\bq_\bu_\ba_\bn_\bt_\bu_\bm] [_\ba_\br_\br_\ba_\by]
- Read lines from the standard input into the indexed array vari-
- able _\ba_\br_\br_\ba_\by, or from file descriptor _\bf_\bd if the -\b-u\bu option is sup-
- plied. The variable M\bMA\bAP\bPF\bFI\bIL\bLE\bE is the default _\ba_\br_\br_\ba_\by. Options, if
+ Read lines from the standard input into the indexed array vari-
+ able _\ba_\br_\br_\ba_\by, or from file descriptor _\bf_\bd if the -\b-u\bu option is sup-
+ plied. The variable M\bMA\bAP\bPF\bFI\bIL\bLE\bE is the default _\ba_\br_\br_\ba_\by. Options, if
supplied, have the following meanings:
- -\b-d\bd The first character of _\bd_\be_\bl_\bi_\bm is used to terminate each
- input line, rather than newline. If _\bd_\be_\bl_\bi_\bm is the empty
+ -\b-d\bd The first character of _\bd_\be_\bl_\bi_\bm is used to terminate each
+ input line, rather than newline. If _\bd_\be_\bl_\bi_\bm is the empty
string, m\bma\bap\bpf\bfi\bil\ble\be will terminate a line when it reads a NUL
character.
- -\b-n\bn Copy at most _\bc_\bo_\bu_\bn_\bt lines. If _\bc_\bo_\bu_\bn_\bt is 0, all lines are
+ -\b-n\bn Copy at most _\bc_\bo_\bu_\bn_\bt lines. If _\bc_\bo_\bu_\bn_\bt is 0, all lines are
copied.
- -\b-O\bO Begin assigning to _\ba_\br_\br_\ba_\by at index _\bo_\br_\bi_\bg_\bi_\bn. The default in-
- dex is 0.
+ -\b-O\bO Begin assigning to _\ba_\br_\br_\ba_\by at index _\bo_\br_\bi_\bg_\bi_\bn. The default
+ index is 0.
-\b-s\bs Discard the first _\bc_\bo_\bu_\bn_\bt lines read.
- -\b-t\bt Remove a trailing _\bd_\be_\bl_\bi_\bm (default newline) from each line
+ -\b-t\bt Remove a trailing _\bd_\be_\bl_\bi_\bm (default newline) from each line
read.
- -\b-u\bu Read lines from file descriptor _\bf_\bd instead of the stan-
+ -\b-u\bu Read lines from file descriptor _\bf_\bd instead of the stan-
dard input.
- -\b-C\bC Evaluate _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk each time _\bq_\bu_\ba_\bn_\bt_\bu_\bm lines are read. The
+ -\b-C\bC Evaluate _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk each time _\bq_\bu_\ba_\bn_\bt_\bu_\bm lines are read. The
-\b-c\bc option specifies _\bq_\bu_\ba_\bn_\bt_\bu_\bm.
- -\b-c\bc Specify the number of lines read between each call to
+ -\b-c\bc Specify the number of lines read between each call to
_\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk.
- If -\b-C\bC is specified without -\b-c\bc, the default quantum is 5000. When
- _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated, it is supplied the index of the next ar-
- ray element to be assigned and the line to be assigned to that
- element as additional arguments. _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated after the
- line is read but before the array element is assigned.
+ If -\b-C\bC is specified without -\b-c\bc, the default quantum is 5000.
+ When _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated, it is supplied the index of the next
+ array element to be assigned and the line to be assigned to that
+ element as additional arguments. _\bc_\ba_\bl_\bl_\bb_\ba_\bc_\bk is evaluated after
+ the line is read but before the array element is assigned.
- If not supplied with an explicit origin, m\bma\bap\bpf\bfi\bil\ble\be will clear _\ba_\br_\b-
+ If not supplied with an explicit origin, m\bma\bap\bpf\bfi\bil\ble\be will clear _\ba_\br_\b-
_\br_\ba_\by before assigning to it.
- m\bma\bap\bpf\bfi\bil\ble\be returns successfully unless an invalid option or option
- argument is supplied, _\ba_\br_\br_\ba_\by is invalid or unassignable, or if
+ m\bma\bap\bpf\bfi\bil\ble\be returns successfully unless an invalid option or option
+ argument is supplied, _\ba_\br_\br_\ba_\by is invalid or unassignable, or if
_\ba_\br_\br_\ba_\by is not an indexed array.
p\bpo\bop\bpd\bd [-n\bn] [+_\bn] [-_\bn]
- Removes entries from the directory stack. The elements are num-
- bered from 0 starting at the first directory listed by d\bdi\bir\brs\bs.
- With no arguments, p\bpo\bop\bpd\bd removes the top directory from the
- stack, and changes to the new top directory. Arguments, if sup-
+ Removes entries from the directory stack. The elements are num-
+ bered from 0 starting at the first directory listed by d\bdi\bir\brs\bs.
+ With no arguments, p\bpo\bop\bpd\bd removes the top directory from the
+ stack, and changes to the new top directory. Arguments, if sup-
plied, have the following meanings:
- -\b-n\bn Suppresses the normal change of directory when removing
+ -\b-n\bn Suppresses the normal change of directory when removing
directories from the stack, so that only the stack is ma-
nipulated.
- +\b+_\bn Removes the _\bnth entry counting from the left of the list
- shown by d\bdi\bir\brs\bs, starting with zero, from the stack. For
- example: ``popd +0'' removes the first directory, ``popd
+ +\b+_\bn Removes the _\bnth entry counting from the left of the list
+ shown by d\bdi\bir\brs\bs, starting with zero, from the stack. For
+ example: ``popd +0'' removes the first directory, ``popd
+1'' the second.
-\b-_\bn Removes the _\bnth entry counting from the right of the list
- shown by d\bdi\bir\brs\bs, starting with zero. For example: ``popd
- -0'' removes the last directory, ``popd -1'' the next to
+ shown by d\bdi\bir\brs\bs, starting with zero. For example: ``popd
+ -0'' removes the last directory, ``popd -1'' the next to
last.
- If the top element of the directory stack is modified, and the
- _\b-_\bn option was not supplied, p\bpo\bop\bpd\bd uses the c\bcd\bd builtin to change
- to the directory at the top of the stack. If the c\bcd\bd fails, p\bpo\bop\bpd\bd
+ If the top element of the directory stack is modified, and the
+ _\b-_\bn option was not supplied, p\bpo\bop\bpd\bd uses the c\bcd\bd builtin to change
+ to the directory at the top of the stack. If the c\bcd\bd fails, p\bpo\bop\bpd\bd
returns a non-zero value.
- Otherwise, p\bpo\bop\bpd\bd returns false if an invalid option is encoun-
+ Otherwise, p\bpo\bop\bpd\bd returns false if an invalid option is encoun-
tered, the directory stack is empty, or a non-existent directory
stack entry is specified.
- If the p\bpo\bop\bpd\bd command is successful, bash runs d\bdi\bir\brs\bs to show the
- final contents of the directory stack, and the return status is
+ If the p\bpo\bop\bpd\bd command is successful, bash runs d\bdi\bir\brs\bs to show the
+ final contents of the directory stack, and the return status is
0.
p\bpr\bri\bin\bnt\btf\bf [-\b-v\bv _\bv_\ba_\br] _\bf_\bo_\br_\bm_\ba_\bt [_\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs]
- Write the formatted _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs to the standard output under the
- control of the _\bf_\bo_\br_\bm_\ba_\bt. The -\b-v\bv option causes the output to be as-
- signed to the variable _\bv_\ba_\br rather than being printed to the
+ Write the formatted _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs to the standard output under the
+ control of the _\bf_\bo_\br_\bm_\ba_\bt. The -\b-v\bv option causes the output to be
+ assigned to the variable _\bv_\ba_\br rather than being printed to the
standard output.
- The _\bf_\bo_\br_\bm_\ba_\bt is a character string which contains three types of
- objects: plain characters, which are simply copied to standard
- output, character escape sequences, which are converted and
- copied to the standard output, and format specifications, each
- of which causes printing of the next successive _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt. In ad-
- dition to the standard _\bp_\br_\bi_\bn_\bt_\bf(3) format characters c\bcs\bsn\bnd\bdi\bio\bou\bux\bxX\bXe\beE\bEf\bf-\b-
- F\bFg\bgG\bGa\baA\bA, p\bpr\bri\bin\bnt\btf\bf interprets the following additional format speci-
- fiers:
+ The _\bf_\bo_\br_\bm_\ba_\bt is a character string which contains three types of
+ objects: plain characters, which are simply copied to standard
+ output, character escape sequences, which are converted and
+ copied to the standard output, and format specifications, each
+ of which causes printing of the next successive _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt. In
+ addition to the standard _\bp_\br_\bi_\bn_\bt_\bf(3) format characters c\bcs\bsn\bnd\bdi\bio\bou\bux\bxX\bXe\be-\b-
+ E\bEf\bfF\bFg\bgG\bGa\baA\bA, p\bpr\bri\bin\bnt\btf\bf interprets the following additional format spec-
+ ifiers:
%\b%b\bb causes p\bpr\bri\bin\bnt\btf\bf to expand backslash escape sequences in the
corresponding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt in the same way as e\bec\bch\bho\bo -\b-e\be.
- %\b%q\bq causes p\bpr\bri\bin\bnt\btf\bf to output the corresponding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt in a
- format that can be reused as shell input. %\b%q\bq and %\b%Q\bQ use
- the $\b$'\b''\b' quoting style if any characters in the argument
- string require it, and backslash quoting otherwise. If
- the format string uses the _\bp_\br_\bi_\bn_\bt_\bf alternate form, these
+ %\b%q\bq causes p\bpr\bri\bin\bnt\btf\bf to output the corresponding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt in a
+ format that can be reused as shell input. %\b%q\bq and %\b%Q\bQ use
+ the $\b$'\b''\b' quoting style if any characters in the argument
+ string require it, and backslash quoting otherwise. If
+ the format string uses the _\bp_\br_\bi_\bn_\bt_\bf alternate form, these
two formats quote the argument string using single
quotes.
- %\b%Q\bQ like %\b%q\bq, but applies any supplied precision to the _\ba_\br_\bg_\bu_\b-
+ %\b%Q\bQ like %\b%q\bq, but applies any supplied precision to the _\ba_\br_\bg_\bu_\b-
_\bm_\be_\bn_\bt before quoting it.
%\b%(\b(_\bd_\ba_\bt_\be_\bf_\bm_\bt)\b)T\bT
- causes p\bpr\bri\bin\bnt\btf\bf to output the date-time string resulting
- from using _\bd_\ba_\bt_\be_\bf_\bm_\bt as a format string for _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3).
+ causes p\bpr\bri\bin\bnt\btf\bf to output the date-time string resulting
+ from using _\bd_\ba_\bt_\be_\bf_\bm_\bt as a format string for _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3).
The corresponding _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt is an integer representing the
- number of seconds since the epoch. Two special argument
- values may be used: -1 represents the current time, and
- -2 represents the time the shell was invoked. If no argu-
- ment is specified, conversion behaves as if -1 had been
- given. This is an exception to the usual p\bpr\bri\bin\bnt\btf\bf behavior.
+ number of seconds since the epoch. Two special argument
+ values may be used: -1 represents the current time, and
+ -2 represents the time the shell was invoked. If no ar-
+ gument is specified, conversion behaves as if -1 had been
+ given. This is an exception to the usual p\bpr\bri\bin\bnt\btf\bf behav-
+ ior.
The %b, %q, and %T format specifiers all use the field width and
precision arguments from the format specification and write that
is the ASCII value of the following character.
The _\bf_\bo_\br_\bm_\ba_\bt is reused as necessary to consume all of the _\ba_\br_\bg_\bu_\b-
- _\bm_\be_\bn_\bt_\bs. If the _\bf_\bo_\br_\bm_\ba_\bt requires more _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs than are supplied,
+ _\bm_\be_\bn_\bt_\bs. If the _\bf_\bo_\br_\bm_\ba_\bt requires more _\ba_\br_\bg_\bu_\bm_\be_\bn_\bt_\bs than are supplied,
the extra format specifications behave as if a zero value or
- null string, as appropriate, had been supplied. The return value
- is zero on success, non-zero if an invalid option is supplied or
- a write or assignment error occurs.
+ null string, as appropriate, had been supplied. The return
+ value is zero on success, non-zero if an invalid option is sup-
+ plied or a write or assignment error occurs.
p\bpu\bus\bsh\bhd\bd [-\b-n\bn] [+_\bn] [-_\bn]
p\bpu\bus\bsh\bhd\bd [-\b-n\bn] [_\bd_\bi_\br]
Adds a directory to the top of the directory stack, or rotates
the stack, making the new top of the stack the current working
- directory. With no arguments, p\bpu\bus\bsh\bhd\bd exchanges the top two ele-
- ments of the directory stack. Arguments, if supplied, have the
+ directory. With no arguments, p\bpu\bus\bsh\bhd\bd exchanges the top two ele-
+ ments of the directory stack. Arguments, if supplied, have the
following meanings:
-\b-n\bn Suppresses the normal change of directory when rotating
or adding directories to the stack, so that only the
After the stack has been modified, if the -\b-n\bn option was not sup-
plied, p\bpu\bus\bsh\bhd\bd uses the c\bcd\bd builtin to change to the directory at
- the top of the stack. If the c\bcd\bd fails, p\bpu\bus\bsh\bhd\bd returns a non-zero
+ the top of the stack. If the c\bcd\bd fails, p\bpu\bus\bsh\bhd\bd returns a non-zero
value.
Otherwise, if no arguments are supplied, p\bpu\bus\bsh\bhd\bd returns 0 unless
- the directory stack is empty. When rotating the directory stack,
- p\bpu\bus\bsh\bhd\bd returns 0 unless the directory stack is empty or a non-ex-
- istent directory stack element is specified.
+ the directory stack is empty. When rotating the directory
+ stack, p\bpu\bus\bsh\bhd\bd returns 0 unless the directory stack is empty or a
+ non-existent directory stack element is specified.
If the p\bpu\bus\bsh\bhd\bd command is successful, bash runs d\bdi\bir\brs\bs to show the
final contents of the directory stack.
Print the absolute pathname of the current working directory.
The pathname printed contains no symbolic links if the -\b-P\bP option
is supplied or the -\b-o\bo p\bph\bhy\bys\bsi\bic\bca\bal\bl option to the s\bse\bet\bt builtin command
- is enabled. If the -\b-L\bL option is used, the pathname printed may
- contain symbolic links. The return status is 0 unless an error
+ is enabled. If the -\b-L\bL option is used, the pathname printed may
+ contain symbolic links. The return status is 0 unless an error
occurs while reading the name of the current directory or an in-
valid option is supplied.
scriptor _\bf_\bd supplied as an argument to the -\b-u\bu option, split into
words as described in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg, and the
first word is assigned to the first _\bn_\ba_\bm_\be, the second word to the
- second _\bn_\ba_\bm_\be, and so on. If there are more words than names, the
+ second _\bn_\ba_\bm_\be, and so on. If there are more words than names, the
remaining words and their intervening delimiters are assigned to
- the last _\bn_\ba_\bm_\be. If there are fewer words read from the input
+ the last _\bn_\ba_\bm_\be. If there are fewer words read from the input
stream than names, the remaining names are assigned empty val-
- ues. The characters in I\bIF\bFS\bS are used to split the line into words
- using the same rules the shell uses for expansion (described in
- _\bb_\ba_\bs_\bh_\b(_\b1_\b) under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg). The backslash character (\\b\) may
- be used to remove any special meaning for the next character
- read and for line continuation. Options, if supplied, have the
- following meanings:
+ ues. The characters in I\bIF\bFS\bS are used to split the line into
+ words using the same rules the shell uses for expansion (de-
+ scribed in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under W\bWo\bor\brd\bd S\bSp\bpl\bli\bit\btt\bti\bin\bng\bg). The backslash charac-
+ ter (\\b\) may be used to remove any special meaning for the next
+ character read and for line continuation. Options, if supplied,
+ have the following meanings:
-\b-a\ba _\ba_\bn_\ba_\bm_\be
The words are assigned to sequential indices of the array
- variable _\ba_\bn_\ba_\bm_\be, starting at 0. _\ba_\bn_\ba_\bm_\be is unset before any
+ variable _\ba_\bn_\ba_\bm_\be, starting at 0. _\ba_\bn_\ba_\bm_\be is unset before any
new values are assigned. Other _\bn_\ba_\bm_\be arguments are ig-
nored.
-\b-d\bd _\bd_\be_\bl_\bi_\bm
character.
-\b-e\be If the standard input is coming from a terminal, r\bre\bea\bad\bd
uses r\bre\bea\bad\bdl\bli\bin\bne\be (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) to obtain the
- line. Readline uses the current (or default, if line
+ line. Readline uses the current (or default, if line
editing was not previously active) editing settings, but
uses readline's default filename completion.
-\b-E\bE If the standard input is coming from a terminal, r\bre\bea\bad\bd
uses r\bre\bea\bad\bdl\bli\bin\bne\be (see R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) to obtain the
- line. Readline uses the current (or default, if line
+ line. Readline uses the current (or default, if line
editing was not previously active) editing settings, but
uses bash's default completion, including programmable
completion.
EOF is encountered or r\bre\bea\bad\bd times out. Delimiter charac-
ters encountered in the input are not treated specially
and do not cause r\bre\bea\bad\bd to return until _\bn_\bc_\bh_\ba_\br_\bs characters
- are read. The result is not split on the characters in
+ are read. The result is not split on the characters in
I\bIF\bFS\bS; the intent is that the variable is assigned exactly
the characters read (with the exception of backslash; see
the -\b-r\br option below).
-\b-p\bp _\bp_\br_\bo_\bm_\bp_\bt
Display _\bp_\br_\bo_\bm_\bp_\bt on standard error, without a trailing new-
- line, before attempting to read any input. The prompt is
+ line, before attempting to read any input. The prompt is
displayed only if input is coming from a terminal.
- -\b-r\br Backslash does not act as an escape character. The back-
- slash is considered to be part of the line. In particu-
+ -\b-r\br Backslash does not act as an escape character. The back-
+ slash is considered to be part of the line. In particu-
lar, a backslash-newline pair may not then be used as a
line continuation.
- -\b-s\bs Silent mode. If input is coming from a terminal, charac-
+ -\b-s\bs Silent mode. If input is coming from a terminal, charac-
ters are not echoed.
-\b-t\bt _\bt_\bi_\bm_\be_\bo_\bu_\bt
Cause r\bre\bea\bad\bd to time out and return failure if a complete
line of input (or a specified number of characters) is
- not read within _\bt_\bi_\bm_\be_\bo_\bu_\bt seconds. _\bt_\bi_\bm_\be_\bo_\bu_\bt may be a decimal
- number with a fractional portion following the decimal
- point. This option is only effective if r\bre\bea\bad\bd is reading
- input from a terminal, pipe, or other special file; it
- has no effect when reading from regular files. If r\bre\bea\bad\bd
- times out, r\bre\bea\bad\bd saves any partial input read into the
- specified variable _\bn_\ba_\bm_\be. If _\bt_\bi_\bm_\be_\bo_\bu_\bt is 0, r\bre\bea\bad\bd returns
- immediately, without trying to read any data. The exit
- status is 0 if input is available on the specified file
- descriptor, or the read will return EOF, non-zero other-
- wise. The exit status is greater than 128 if the timeout
- is exceeded.
+ not read within _\bt_\bi_\bm_\be_\bo_\bu_\bt seconds. _\bt_\bi_\bm_\be_\bo_\bu_\bt may be a deci-
+ mal number with a fractional portion following the deci-
+ mal point. This option is only effective if r\bre\bea\bad\bd is
+ reading input from a terminal, pipe, or other special
+ file; it has no effect when reading from regular files.
+ If r\bre\bea\bad\bd times out, r\bre\bea\bad\bd saves any partial input read into
+ the specified variable _\bn_\ba_\bm_\be. If _\bt_\bi_\bm_\be_\bo_\bu_\bt is 0, r\bre\bea\bad\bd re-
+ turns immediately, without trying to read any data. The
+ exit status is 0 if input is available on the specified
+ file descriptor, or the read will return EOF, non-zero
+ otherwise. The exit status is greater than 128 if the
+ timeout is exceeded.
-\b-u\bu _\bf_\bd Read input from file descriptor _\bf_\bd.
If no _\bn_\ba_\bm_\be_\bs are supplied, the line read, without the ending de-
limiter but otherwise unmodified, is assigned to the variable
- R\bRE\bEP\bPL\bLY\bY. The exit status is zero, unless end-of-file is encoun-
+ R\bRE\bEP\bPL\bLY\bY. The exit status is zero, unless end-of-file is encoun-
tered, r\bre\bea\bad\bd times out (in which case the status is greater than
128), a variable assignment error (such as assigning to a read-
only variable) occurs, or an invalid file descriptor is supplied
r\bre\bea\bad\bdo\bon\bnl\bly\by [-\b-a\baA\bAf\bf] [-\b-p\bp] [_\bn_\ba_\bm_\be[=_\bw_\bo_\br_\bd] ...]
The given _\bn_\ba_\bm_\be_\bs are marked readonly; the values of these _\bn_\ba_\bm_\be_\bs
- may not be changed by subsequent assignment. If the -\b-f\bf option is
- supplied, the functions corresponding to the _\bn_\ba_\bm_\be_\bs are so
- marked. The -\b-a\ba option restricts the variables to indexed arrays;
- the -\b-A\bA option restricts the variables to associative arrays. If
- both options are supplied, -\b-A\bA takes precedence. If no _\bn_\ba_\bm_\be argu-
- ments are given, or if the -\b-p\bp option is supplied, a list of all
- readonly names is printed. The other options may be used to re-
- strict the output to a subset of the set of readonly names. The
- -\b-p\bp option causes output to be displayed in a format that may be
- reused as input. If a variable name is followed by =_\bw_\bo_\br_\bd, the
- value of the variable is set to _\bw_\bo_\br_\bd. The return status is 0 un-
- less an invalid option is encountered, one of the _\bn_\ba_\bm_\be_\bs is not a
- valid shell variable name, or -\b-f\bf is supplied with a _\bn_\ba_\bm_\be that is
- not a function.
+ may not be changed by subsequent assignment. If the -\b-f\bf option
+ is supplied, the functions corresponding to the _\bn_\ba_\bm_\be_\bs are so
+ marked. The -\b-a\ba option restricts the variables to indexed ar-
+ rays; the -\b-A\bA option restricts the variables to associative ar-
+ rays. If both options are supplied, -\b-A\bA takes precedence. If no
+ _\bn_\ba_\bm_\be arguments are given, or if the -\b-p\bp 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 -\b-p\bp option causes output to be displayed in a format
+ that may be reused as input. If a variable name is followed by
+ =_\bw_\bo_\br_\bd, the value of the variable is set to _\bw_\bo_\br_\bd. The return
+ status is 0 unless an invalid option is encountered, one of the
+ _\bn_\ba_\bm_\be_\bs is not a valid shell variable name, or -\b-f\bf is supplied with
+ a _\bn_\ba_\bm_\be that is not a function.
r\bre\bet\btu\bur\brn\bn [_\bn]
Causes a function to stop executing and return the value speci-
- fied by _\bn to its caller. If _\bn is omitted, the return status is
- that of the last command executed in the function body. If r\bre\be-\b-
+ fied by _\bn to its caller. If _\bn is omitted, the return status is
+ that of the last command executed in the function body. If r\bre\be-\b-
t\btu\bur\brn\bn is executed by a trap handler, the last command used to de-
termine the status is the last command executed before the trap
- handler. If r\bre\bet\btu\bur\brn\bn is executed during a D\bDE\bEB\bBU\bUG\bG trap, the last
+ handler. If r\bre\bet\btu\bur\brn\bn is executed during a D\bDE\bEB\bBU\bUG\bG trap, the last
command used to determine the status is the last command exe-
cuted by the trap handler before r\bre\bet\btu\bur\brn\bn was invoked. If r\bre\bet\btu\bur\brn\bn
is used outside a function, but during execution of a script by
- the .\b. (s\bso\bou\bur\brc\bce\be) command, it causes the shell to stop executing
+ the .\b. (s\bso\bou\bur\brc\bce\be) command, it causes the shell to stop executing
that script and return either _\bn or the exit status of the last
command executed within the script as the exit status of the
- script. If _\bn is supplied, the return value is its least signifi-
- cant 8 bits. The return status is non-zero if r\bre\bet\btu\bur\brn\bn is supplied
- a non-numeric argument, or is used outside a function and not
- during execution of a script by .\b. or s\bso\bou\bur\brc\bce\be. Any command associ-
- ated with the R\bRE\bET\bTU\bUR\bRN\bN trap is executed before execution resumes
- after the function or script.
+ script. If _\bn is supplied, the return value is its least signif-
+ icant 8 bits. The return status is non-zero if r\bre\bet\btu\bur\brn\bn is sup-
+ plied a non-numeric argument, or is used outside a function and
+ not during execution of a script by .\b. or s\bso\bou\bur\brc\bce\be. Any command
+ associated with the R\bRE\bET\bTU\bUR\bRN\bN trap is executed before execution re-
+ sumes after the function or script.
s\bse\bet\bt [-\b-a\bab\bbe\bef\bfh\bhk\bkm\bmn\bnp\bpt\btu\buv\bvx\bxB\bBC\bCE\bEH\bHP\bPT\bT] [-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be] [-\b--\b-] [-\b-] [_\ba_\br_\bg ...]
s\bse\bet\bt [+\b+a\bab\bbe\bef\bfh\bhk\bkm\bmn\bnp\bpt\btu\buv\bvx\bxB\bBC\bCE\bEH\bHP\bPT\bT] [+\b+o\bo _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be] [-\b--\b-] [-\b-] [_\ba_\br_\bg ...]
s\bse\bet\bt -\b-o\bo
s\bse\bet\bt +\b+o\bo Without options, display the name and value of each shell vari-
able in a format that can be reused as input for setting or re-
- setting the currently-set variables. Read-only variables cannot
- be reset. In _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, only shell variables are listed. The
+ setting the currently-set variables. Read-only variables cannot
+ be reset. In _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, 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 values for the
- positional parameters and are assigned, in order, to $\b$1\b1, $\b$2\b2, .\b..\b..\b.
- $\b$_\bn. Options, if specified, have the following meanings:
+ are specified, they set or unset shell attributes. Any argu-
+ ments remaining after option processing are treated as values
+ for the positional parameters and are assigned, in order, to $\b$1\b1,
+ $\b$2\b2, .\b..\b..\b. $\b$_\bn. Options, if specified, have the following mean-
+ ings:
-\b-a\ba Each variable or function that is created or modified is
- given the export attribute and marked for export to the
+ given the export attribute and marked for export to the
environment of subsequent commands.
- -\b-b\bb Report the status of terminated background jobs immedi-
- ately, rather than before the next primary prompt. This
+ -\b-b\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.
- -\b-e\be Exit immediately if a _\bp_\bi_\bp_\be_\bl_\bi_\bn_\be (which may consist of a
- single _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd), a _\bl_\bi_\bs_\bt, or a _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd _\bc_\bo_\bm_\bm_\ba_\bn_\bd
- (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR in _\bb_\ba_\bs_\bh_\b(_\b1_\b)), exits with a non-zero
- status. The shell does not exit if the command that
- fails is part of the command list immediately following
+ -\b-e\be Exit immediately if a _\bp_\bi_\bp_\be_\bl_\bi_\bn_\be (which may consist of a
+ single _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd), a _\bl_\bi_\bs_\bt, or a _\bc_\bo_\bm_\bp_\bo_\bu_\bn_\bd _\bc_\bo_\bm_\bm_\ba_\bn_\bd
+ (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR in _\bb_\ba_\bs_\bh_\b(_\b1_\b)), exits with a non-zero
+ status. The shell does not exit if the command that
+ fails is part of the command list immediately following
a w\bwh\bhi\bil\ble\be or u\bun\bnt\bti\bil\bl keyword, part of the test following the
- i\bif\bf or e\bel\bli\bif\bf reserved words, part of any command executed
- in a &\b&&\b& or |\b||\b| list except the command following the fi-
+ i\bif\bf or e\bel\bli\bif\bf reserved words, part of any command executed
+ in a &\b&&\b& or |\b||\b| list except the command following the fi-
nal &\b&&\b& or |\b||\b|, any command in a pipeline but the last, or
- if the command's return value is being inverted with !\b!.
- If a compound command other than a subshell returns a
- non-zero status because a command failed while -\b-e\be was
- being ignored, the shell does not exit. A trap on E\bER\bRR\bR,
- if set, is executed before the shell exits. This option
+ if the command's return value is being inverted with !\b!.
+ If a compound command other than a subshell returns a
+ non-zero status because a command failed while -\b-e\be was
+ being ignored, the shell does not exit. A trap on E\bER\bRR\bR,
+ if set, is executed before the shell exits. This option
applies to the shell environment and each subshell envi-
ronment separately (see C\bCO\bOM\bMM\bMA\bAN\bND\bD E\bEX\bXE\bEC\bCU\bUT\bTI\bIO\bON\bN E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT in
_\bb_\ba_\bs_\bh_\b(_\b1_\b)), and may cause subshells to exit before execut-
ing all the commands in the subshell.
- If a compound command or shell function executes in a
- context where -\b-e\be is being ignored, none of the commands
- executed within the compound command or function body
- will be affected by the -\b-e\be setting, even if -\b-e\be is set
- and a command returns a failure status. If a compound
- command or shell function sets -\b-e\be while executing in a
- context where -\b-e\be is ignored, that setting will not have
- any effect until the compound command or the command
+ If a compound command or shell function executes in a
+ context where -\b-e\be is being ignored, none of the commands
+ executed within the compound command or function body
+ will be affected by the -\b-e\be setting, even if -\b-e\be is set
+ and a command returns a failure status. If a compound
+ command or shell function sets -\b-e\be while executing in a
+ context where -\b-e\be is ignored, that setting will not have
+ any effect until the compound command or the command
containing the function call completes.
-\b-f\bf Disable pathname expansion.
- -\b-h\bh Remember the location of commands as they are looked up
- for execution. This is enabled by default.
- -\b-k\bk All arguments in the form of assignment statements are
- placed in the environment for a command, not just those
+ -\b-h\bh Remember the location of commands as they are looked up
+ for execution. This is enabled by default.
+ -\b-k\bk All arguments in the form of assignment statements are
+ placed in the environment for a command, not just those
that precede the command name.
- -\b-m\bm Monitor mode. Job control is enabled. This option is on
- by default for interactive shells on systems that sup-
- port it (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). All processes run
- in a separate process group. When a background job com-
- pletes, the shell prints a line containing its exit sta-
- tus.
- -\b-n\bn Read commands but do not execute them. This may be used
- to check a shell script for syntax errors. This is ig-
+ -\b-m\bm Monitor mode. Job control is enabled. This option is
+ on by default for interactive shells on systems that
+ support it (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). All processes
+ run in a separate process group. When a background job
+ completes, the shell prints a line containing its exit
+ status.
+ -\b-n\bn Read commands but do not execute them. This may be used
+ to check a shell script for syntax errors. This is ig-
nored by interactive shells.
-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be
The _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be can be one of the following:
Same as -\b-a\ba.
b\bbr\bra\bac\bce\bee\bex\bxp\bpa\ban\bnd\bd
Same as -\b-B\bB.
- e\bem\bma\bac\bcs\bs Use an emacs-style command line editing inter-
- face. This is enabled by default when the shell
+ e\bem\bma\bac\bcs\bs 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 -\b--\b-n\bno\boe\bed\bdi\bit\bti\bin\bng\bg option. This also affects the
+ the -\b--\b-n\bno\boe\bed\bdi\bit\bti\bin\bng\bg option. This also affects the
editing interface used for r\bre\bea\bad\bd -\b-e\be.
e\ber\brr\bre\bex\bxi\bit\bt Same as -\b-e\be.
e\ber\brr\brt\btr\bra\bac\bce\be
h\bha\bas\bsh\bha\bal\bll\bl Same as -\b-h\bh.
h\bhi\bis\bst\bte\bex\bxp\bpa\ban\bnd\bd
Same as -\b-H\bH.
- h\bhi\bis\bst\bto\bor\bry\by Enable command history, as described in _\bb_\ba_\bs_\bh_\b(_\b1_\b)
- under H\bHI\bIS\bST\bTO\bOR\bRY\bY. This option is on by default in
+ h\bhi\bis\bst\bto\bor\bry\by Enable command history, as described in _\bb_\ba_\bs_\bh_\b(_\b1_\b)
+ under H\bHI\bIS\bST\bTO\bOR\bRY\bY. This option is on by default in
interactive shells.
i\big\bgn\bno\bor\bre\bee\beo\bof\bf
- The effect is as if the shell command ``IG-
- NOREEOF=10'' had been executed (see S\bSh\bhe\bel\bll\bl V\bVa\bar\bri\bi-\b-
+ The effect is as if the shell command ``IG-
+ NOREEOF=10'' had been executed (see S\bSh\bhe\bel\bll\bl V\bVa\bar\bri\bi-\b-
a\bab\bbl\ble\bes\bs in _\bb_\ba_\bs_\bh_\b(_\b1_\b)).
k\bke\bey\byw\bwo\bor\brd\bd Same as -\b-k\bk.
m\bmo\bon\bni\bit\bto\bor\br Same as -\b-m\bm.
p\bph\bhy\bys\bsi\bic\bca\bal\bl
Same as -\b-P\bP.
p\bpi\bip\bpe\bef\bfa\bai\bil\bl
- 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.
- p\bpo\bos\bsi\bix\bx Change the behavior of b\bba\bas\bsh\bh where the default
- operation differs from the POSIX standard to
- match the standard (_\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be). See S\bSE\bEE\bE A\bAL\bLS\bSO\bO in
- _\bb_\ba_\bs_\bh_\b(_\b1_\b) for a reference to a document that de-
- tails how posix mode affects bash's behavior.
+ p\bpo\bos\bsi\bix\bx Change the behavior of b\bba\bas\bsh\bh where the default
+ operation differs from the POSIX standard to
+ match the standard (_\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be). See S\bSE\bEE\bE A\bAL\bLS\bSO\bO
+ in _\bb_\ba_\bs_\bh_\b(_\b1_\b) for a reference to a document that
+ details how posix mode affects bash's behavior.
p\bpr\bri\biv\bvi\bil\ble\beg\bge\bed\bd
Same as -\b-p\bp.
v\bve\ber\brb\bbo\bos\bse\be Same as -\b-v\bv.
- v\bvi\bi Use a vi-style command line editing interface.
+ v\bvi\bi Use a vi-style command line editing interface.
This also affects the editing interface used for
r\bre\bea\bad\bd -\b-e\be.
x\bxt\btr\bra\bac\bce\be Same as -\b-x\bx.
- If -\b-o\bo is supplied with no _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints the
- current shell option settings. If +\b+o\bo is supplied with no
- _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints a series of s\bse\bet\bt commands to
- recreate the current option settings on the standard
+ If -\b-o\bo is supplied with no _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints the
+ current shell option settings. If +\b+o\bo is supplied with
+ no _\bo_\bp_\bt_\bi_\bo_\bn_\b-_\bn_\ba_\bm_\be, s\bse\bet\bt prints a series of s\bse\bet\bt commands to
+ recreate the current option settings on the standard
output.
- -\b-p\bp Turn on _\bp_\br_\bi_\bv_\bi_\bl_\be_\bg_\be_\bd mode. In this mode, the $\b$E\bEN\bNV\bV and
- $\b$B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV files are not processed, shell functions are
- not inherited from the environment, and the S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS,
- B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS, C\bCD\bDP\bPA\bAT\bTH\bH, and G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE variables, if they ap-
- pear 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 -\b-p\bp option is not sup-
+ -\b-p\bp Turn on _\bp_\br_\bi_\bv_\bi_\bl_\be_\bg_\be_\bd mode. In this mode, the $\b$E\bEN\bNV\bV and
+ $\b$B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV files are not processed, shell functions are
+ not inherited from the environment, and the S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS,
+ B\bBA\bAS\bSH\bHO\bOP\bPT\bTS\bS, C\bCD\bDP\bPA\bAT\bTH\bH, and G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE variables, if they ap-
+ pear 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 -\b-p\bp option is not sup-
plied, these actions are taken and the effective user id
- is set to the real user id. If the -\b-p\bp option is supplied
- at startup, the effective user id is not reset. Turning
- this option off causes the effective user and group ids
- to be set to the real user and group ids.
- -\b-r\br Enable restricted shell mode. This option cannot be un-
+ is set to the real user id. If the -\b-p\bp 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.
+ -\b-r\br Enable restricted shell mode. This option cannot be un-
set once it has been set.
-\b-t\bt Exit after reading and executing one command.
-\b-u\bu Treat unset variables and parameters other than the spe-
- cial parameters "@" and "*", or array variables sub-
- scripted with "@" or "*", as an error when performing
- parameter expansion. If expansion is attempted on an un-
- set variable or parameter, the shell prints an error
- message, and, if not interactive, exits with a non-zero
+ cial parameters "@" and "*", or array variables sub-
+ scripted with "@" or "*", 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.
-\b-v\bv Print shell input lines as they are read.
- -\b-x\bx After expanding each _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, f\bfo\bor\br command, c\bca\bas\bse\be
+ -\b-x\bx After expanding each _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, f\bfo\bor\br command, c\bca\bas\bse\be
command, s\bse\bel\ble\bec\bct\bt command, or arithmetic f\bfo\bor\br command, dis-
- play the expanded value of P\bPS\bS4\b4, followed by the command
- and its expanded arguments or associated word list, to
+ play the expanded value of P\bPS\bS4\b4, followed by the command
+ and its expanded arguments or associated word list, to
standard error.
- -\b-B\bB The shell performs brace expansion (see B\bBr\bra\bac\bce\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
- in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). This is on by default.
- -\b-C\bC If set, b\bba\bas\bsh\bh does not overwrite an existing file with
- the >\b>, >\b>&\b&, and <\b<>\b> redirection operators. This may be
+ -\b-B\bB The shell performs brace expansion (see B\bBr\bra\bac\bce\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn
+ in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). This is on by default.
+ -\b-C\bC If set, b\bba\bas\bsh\bh does not overwrite an existing file with
+ the >\b>, >\b>&\b&, and <\b<>\b> redirection operators. This may be
overridden when creating output files by using the redi-
rection operator >\b>|\b| instead of >\b>.
-\b-E\bE If set, any trap on E\bER\bRR\bR is inherited by shell functions,
- command substitutions, and commands executed in a sub-
- shell environment. The E\bER\bRR\bR trap is normally not inher-
+ command substitutions, and commands executed in a sub-
+ shell environment. The E\bER\bRR\bR trap is normally not inher-
ited in such cases.
- -\b-H\bH Enable !\b! style history substitution. This option is on
+ -\b-H\bH Enable !\b! style history substitution. This option is on
by default when the shell is interactive.
- -\b-P\bP If set, the shell does not resolve symbolic links when
- executing commands such as c\bcd\bd that change the current
- working directory. It uses the physical directory struc-
- ture instead. By default, b\bba\bas\bsh\bh follows the logical chain
- of directories when performing commands which change the
- current directory.
- -\b-T\bT If set, any traps on D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN are inherited by
+ -\b-P\bP If set, the shell does not resolve symbolic links when
+ executing commands such as c\bcd\bd that change the current
+ working directory. It uses the physical directory
+ structure instead. By default, b\bba\bas\bsh\bh follows the logical
+ chain of directories when performing commands which
+ change the current directory.
+ -\b-T\bT If set, any traps on D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN are inherited by
shell functions, command substitutions, and commands ex-
- ecuted in a subshell environment. The D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN
+ ecuted in a subshell environment. The D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN
traps are normally not inherited in such cases.
- -\b--\b- If no arguments follow this option, then the positional
- parameters are unset. Otherwise, the positional parame-
- ters are set to the _\ba_\br_\bgs, even if some of them begin
+ -\b--\b- If no arguments follow this option, then the positional
+ parameters are unset. Otherwise, the positional parame-
+ ters are set to the _\ba_\br_\bgs, even if some of them begin
with a -\b-.
- -\b- Signal the end of options, cause all remaining _\ba_\br_\bgs to
- be assigned to the positional parameters. The -\b-x\bx and -\b-v\bv
- options are turned off. If there are no _\ba_\br_\bgs, the posi-
+ -\b- Signal the end of options, cause all remaining _\ba_\br_\bgs to
+ be assigned to the positional parameters. The -\b-x\bx and -\b-v\bv
+ options are turned off. If there are no _\ba_\br_\bgs, 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 $\b$-\b-. The return
- status is always true unless an invalid option is encountered.
+ The options are off by default unless otherwise noted. Using +
+ rather than - causes these options to be turned off. The op-
+ tions can also be specified as arguments to an invocation of the
+ shell. The current set of options may be found in $\b$-\b-. The re-
+ turn status is always true unless an invalid option is encoun-
+ tered.
s\bsh\bhi\bif\bft\bt [_\bn]
The positional parameters from _\bn+1 ... are renamed to $\b$1\b1 .\b..\b..\b..\b.
Parameters represented by the numbers $\b$#\b# down to $\b$#\b#-_\bn+1 are un-
- set. _\bn must be a non-negative number less than or equal to $\b$#\b#.
- If _\bn is 0, no parameters are changed. If _\bn is not given, it is
- assumed to be 1. If _\bn is greater than $\b$#\b#, the positional parame-
- ters are not changed. The return status is greater than zero if
- _\bn is greater than $\b$#\b# or less than zero; otherwise 0.
+ set. _\bn must be a non-negative number less than or equal to $\b$#\b#.
+ If _\bn is 0, no parameters are changed. If _\bn is not given, it is
+ assumed to be 1. If _\bn is greater than $\b$#\b#, the positional param-
+ eters are not changed. The return status is greater than zero
+ if _\bn is greater than $\b$#\b# or less than zero; otherwise 0.
s\bsh\bho\bop\bpt\bt [-\b-p\bpq\bqs\bsu\bu] [-\b-o\bo] [_\bo_\bp_\bt_\bn_\ba_\bm_\be ...]
Toggle the values of settings controlling optional shell behav-
- ior. The settings can be either those listed below, or, if the
+ ior. The settings can be either those listed below, or, if the
-\b-o\bo option is used, those available with the -\b-o\bo option to the s\bse\bet\bt
- builtin command. With no options, or with the -\b-p\bp option, a list
+ builtin command. With no options, or with the -\b-p\bp option, a list
of all settable options is displayed, with an indication of
whether or not each is set; if _\bo_\bp_\bt_\bn_\ba_\bm_\be_\bs are supplied, the output
- is restricted to those options. The -\b-p\bp option causes output to
- be displayed in a form that may be reused as input. Other op-
+ is restricted to those options. The -\b-p\bp option causes output to
+ be displayed in a form that may be reused as input. Other op-
tions have the following meanings:
-\b-s\bs Enable (set) each _\bo_\bp_\bt_\bn_\ba_\bm_\be.
-\b-u\bu Disable (unset) each _\bo_\bp_\bt_\bn_\ba_\bm_\be.
-\b-q\bq Suppresses normal output (quiet mode); the return status
- indicates whether the _\bo_\bp_\bt_\bn_\ba_\bm_\be is set or unset. If multi-
+ indicates whether the _\bo_\bp_\bt_\bn_\ba_\bm_\be is set or unset. If multi-
ple _\bo_\bp_\bt_\bn_\ba_\bm_\be arguments are given with -\b-q\bq, the return sta-
tus is zero if all _\bo_\bp_\bt_\bn_\ba_\bm_\be_\bs are enabled; non-zero other-
wise.
by default.
The return status when listing options is zero if all _\bo_\bp_\bt_\bn_\ba_\bm_\be_\bs
- are enabled, non-zero otherwise. When setting or unsetting op-
+ are enabled, non-zero otherwise. When setting or unsetting op-
tions, the return status is zero unless an _\bo_\bp_\bt_\bn_\ba_\bm_\be is not a
valid shell option.
Deprecated; a synonym for a\bar\brr\bra\bay\by_\b_e\bex\bxp\bpa\ban\bnd\bd_\b_o\bon\bnc\bce\be.
a\bau\but\bto\boc\bcd\bd If set, a command name that is the name of a directory
is executed as if it were the argument to the c\bcd\bd com-
- mand. This option is only used by interactive shells.
+ mand. This option is only used by interactive shells.
c\bcd\bda\bab\bbl\ble\be_\b_v\bva\bar\brs\bs
If set, an argument to the c\bcd\bd builtin command that is
not a directory is assumed to be the name of a variable
whose value is the directory to change to.
c\bcd\bds\bsp\bpe\bel\bll\bl If set, minor errors in the spelling of a directory com-
- ponent in a c\bcd\bd command will be corrected. The errors
+ ponent in a c\bcd\bd command will be corrected. The errors
checked for are transposed characters, a missing charac-
- ter, and one character too many. If a correction is
+ 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.
c\bch\bhe\bec\bck\bkh\bha\bas\bsh\bh
If set, b\bba\bas\bsh\bh checks that a command found in the hash ta-
- ble exists before trying to execute it. If a hashed com-
- mand 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.
c\bch\bhe\bec\bck\bkj\bjo\bob\bbs\bs
If set, b\bba\bas\bsh\bh lists the status of any stopped and running
jobs before exiting an interactive shell. If any jobs
are running, this causes the exit to be deferred until a
second exit is attempted without an intervening command
- (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). The shell always postpones
- exiting if any jobs are stopped.
+ (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). The shell always post-
+ pones exiting if any jobs are stopped.
c\bch\bhe\bec\bck\bkw\bwi\bin\bns\bsi\biz\bze\be
If set, b\bba\bas\bsh\bh checks the window size after each external
(non-builtin) command and, if necessary, updates the
- values of L\bLI\bIN\bNE\bES\bS and C\bCO\bOL\bLU\bUM\bMN\bNS\bS. This option is enabled by
+ values of L\bLI\bIN\bNE\bES\bS and C\bCO\bOL\bLU\bUM\bMN\bNS\bS. This option is enabled by
default.
c\bcm\bmd\bdh\bhi\bis\bst\bt If set, b\bba\bas\bsh\bh attempts to save all lines of a multiple-
- line command in the same history entry. This allows easy
- re-editing of multi-line commands. This option is en-
- abled by default, but only has an effect if command his-
- tory is enabled, as described in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under H\bHI\bIS\bST\bTO\bOR\bRY\bY.
+ line command in the same history entry. This allows
+ easy re-editing of multi-line commands. This option is
+ enabled by default, but only has an effect if command
+ history is enabled, as described in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under H\bHI\bIS\bS-\b-
+ T\bTO\bOR\bRY\bY.
c\bco\bom\bmp\bpa\bat\bt3\b31\b1
c\bco\bom\bmp\bpa\bat\bt3\b32\b2
c\bco\bom\bmp\bpa\bat\bt4\b40\b0
c\bco\bom\bmp\bpa\bat\bt4\b43\b3
c\bco\bom\bmp\bpa\bat\bt4\b44\b4
c\bco\bom\bmp\bpa\bat\bt5\b50\b0
- These control aspects of the shell's compatibility mode
+ These control aspects of the shell's compatibility mode
(see S\bSH\bHE\bEL\bLL\bL C\bCO\bOM\bMP\bPA\bAT\bTI\bIB\bBI\bIL\bLI\bIT\bTY\bY M\bMO\bOD\bDE\bE in _\bb_\ba_\bs_\bh_\b(_\b1_\b)).
c\bco\bom\bmp\bpl\ble\bet\bte\be_\b_f\bfu\bul\bll\blq\bqu\buo\bot\bte\be
- If set, b\bba\bas\bsh\bh quotes all shell metacharacters in file-
- names and directory names when performing completion. If
- not set, b\bba\bas\bsh\bh removes metacharacters such as the dollar
- 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 backslashes to
- quote completed filenames. This variable is set by de-
- fault, which is the default bash behavior in versions
- through 4.2.
+ If set, b\bba\bas\bsh\bh quotes all shell metacharacters in file-
+ names and directory names when performing completion.
+ If not set, b\bba\bas\bsh\bh 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 ex-
+ pand 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.
d\bdi\bir\bre\bex\bxp\bpa\ban\bnd\bd
- If set, b\bba\bas\bsh\bh replaces directory names with the results
- of word expansion when performing filename completion.
- This changes the contents of the readline editing buf-
- fer. If not set, b\bba\bas\bsh\bh attempts to preserve what the user
- typed.
+ If set, b\bba\bas\bsh\bh replaces directory names with the results
+ of word expansion when performing filename completion.
+ This changes the contents of the readline editing buf-
+ fer. If not set, b\bba\bas\bsh\bh attempts to preserve what the
+ user typed.
d\bdi\bir\brs\bsp\bpe\bel\bll\bl
- If set, b\bba\bas\bsh\bh attempts spelling correction on directory
- names during word completion if the directory name ini-
+ If set, b\bba\bas\bsh\bh attempts spelling correction on directory
+ names during word completion if the directory name ini-
tially supplied does not exist.
- d\bdo\bot\btg\bgl\blo\bob\bb If set, b\bba\bas\bsh\bh includes filenames beginning with a `.' in
- the results of pathname expansion. The filenames `\b``\b`.\b.'\b''\b'
- and `\b``\b`.\b..\b.'\b''\b' must always be matched explicitly, even if
+ d\bdo\bot\btg\bgl\blo\bob\bb If set, b\bba\bas\bsh\bh includes filenames beginning with a `.' in
+ the results of pathname expansion. The filenames `\b``\b`.\b.'\b''\b'
+ and `\b``\b`.\b..\b.'\b''\b' must always be matched explicitly, even if
d\bdo\bot\btg\bgl\blo\bob\bb is set.
e\bex\bxe\bec\bcf\bfa\bai\bil\bl
If set, a non-interactive shell will not exit if it can-
- not execute the file specified as an argument to the
- e\bex\bxe\bec\bc builtin command. An interactive shell does not exit
- if e\bex\bxe\bec\bc fails.
+ not execute the file specified as an argument to the
+ e\bex\bxe\bec\bc builtin command. An interactive shell does not
+ exit if e\bex\bxe\bec\bc fails.
e\bex\bxp\bpa\ban\bnd\bd_\b_a\bal\bli\bia\bas\bse\bes\bs
If set, aliases are expanded as described in _\bb_\ba_\bs_\bh_\b(_\b1_\b) un-
- der A\bAL\bLI\bIA\bAS\bSE\bES\bS. This option is enabled by default for in-
+ der A\bAL\bLI\bIA\bAS\bSE\bES\bS. This option is enabled by default for in-
teractive shells.
e\bex\bxt\btd\bde\beb\bbu\bug\bg
- If set at shell invocation, or in a shell startup file,
+ If set at shell invocation, or in a shell startup file,
arrange to execute the debugger profile before the shell
- starts, identical to the -\b--\b-d\bde\beb\bbu\bug\bgg\bge\ber\br option. If set after
- invocation, behavior intended for use by debuggers is
- enabled:
+ starts, identical to the -\b--\b-d\bde\beb\bbu\bug\bgg\bge\ber\br option. If set af-
+ ter invocation, behavior intended for use by debuggers
+ is enabled:
1\b1.\b. The -\b-F\bF option to the d\bde\bec\bcl\bla\bar\bre\be builtin displays the
source file name and line number corresponding to
each function name supplied as an argument.
- 2\b2.\b. If the command run by the D\bDE\bEB\bBU\bUG\bG trap returns a
- non-zero value, the next command is skipped and
+ 2\b2.\b. If the command run by the D\bDE\bEB\bBU\bUG\bG trap returns a
+ non-zero value, the next command is skipped and
not executed.
- 3\b3.\b. If the command run by the D\bDE\bEB\bBU\bUG\bG 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 .\b. or s\bso\bou\bur\brc\bce\be builtins), the shell
+ 3\b3.\b. If the command run by the D\bDE\bEB\bBU\bUG\bG 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 .\b. or s\bso\bou\bur\brc\bce\be builtins), the shell
simulates a call to r\bre\bet\btu\bur\brn\bn.
- 4\b4.\b. B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC and B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV are updated as described
+ 4\b4.\b. B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGC\bC and B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV are updated as described
in their descriptions in _\bb_\ba_\bs_\bh_\b(_\b1_\b)).
- 5\b5.\b. Function tracing is enabled: command substitu-
+ 5\b5.\b. Function tracing is enabled: command substitu-
tion, shell functions, and subshells invoked with
(\b( _\bc_\bo_\bm_\bm_\ba_\bn_\bd )\b) inherit the D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN traps.
- 6\b6.\b. Error tracing is enabled: command substitution,
- shell functions, and subshells invoked with (\b(
+ 6\b6.\b. Error tracing is enabled: command substitution,
+ shell functions, and subshells invoked with (\b(
_\bc_\bo_\bm_\bm_\ba_\bn_\bd )\b) inherit the E\bER\bRR\bR trap.
e\bex\bxt\btg\bgl\blo\bob\bb If set, the extended pattern matching features described
in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn are enabled.
e\bex\bxt\btq\bqu\buo\bot\bte\be
- If set, $\b$'_\bs_\bt_\br_\bi_\bn_\bg' and $\b$"_\bs_\bt_\br_\bi_\bn_\bg" quoting is performed
- within $\b${\b{_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br}\b} expansions enclosed in double
- quotes. This option is enabled by default.
+ If set, $\b$'_\bs_\bt_\br_\bi_\bn_\bg' and $\b$"_\bs_\bt_\br_\bi_\bn_\bg" quoting is performed
+ within $\b${\b{_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br}\b} expansions enclosed in double
+ quotes. This option is enabled by default.
f\bfa\bai\bil\blg\bgl\blo\bob\bb
- 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.
f\bfo\bor\brc\bce\be_\b_f\bfi\big\bgn\bno\bor\bre\be
- If set, the suffixes specified by the F\bFI\bIG\bGN\bNO\bOR\bRE\bE shell
- variable cause words to be ignored when performing word
+ If set, the suffixes specified by the F\bFI\bIG\bGN\bNO\bOR\bRE\bE shell
+ variable cause words to be ignored when performing word
completion even if the ignored words are the only possi-
- ble completions. See S\bSH\bHE\bEL\bLL\bL V\bVA\bAR\bRI\bIA\bAB\bBL\bLE\bES\bS in _\bb_\ba_\bs_\bh_\b(_\b1_\b) for a
- description of F\bFI\bIG\bGN\bNO\bOR\bRE\bE. This option is enabled by de-
+ ble completions. See S\bSH\bHE\bEL\bLL\bL V\bVA\bAR\bRI\bIA\bAB\bBL\bLE\bES\bS in _\bb_\ba_\bs_\bh_\b(_\b1_\b) for a
+ description of F\bFI\bIG\bGN\bNO\bOR\bRE\bE. This option is enabled by de-
fault.
g\bgl\blo\bob\bba\bas\bsc\bci\bii\bir\bra\ban\bng\bge\bes\bs
- If set, range expressions used in pattern matching
- bracket expressions (see P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg in _\bb_\ba_\bs_\bh_\b(_\b1_\b))
+ If set, range expressions used in pattern matching
+ bracket expressions (see P\bPa\bat\btt\bte\ber\brn\bn M\bMa\bat\btc\bch\bhi\bin\bng\bg in _\bb_\ba_\bs_\bh_\b(_\b1_\b))
behave as if in the traditional C locale when performing
- comparisons. That is, the current locale's collating se-
- quence is not taken into account, so b\bb will not collate
- between A\bA and B\bB, and upper-case and lower-case ASCII
- characters will collate together.
+ comparisons. That is, the current locale's collating
+ sequence is not taken into account, so b\bb will not col-
+ late between A\bA and B\bB, and upper-case and lower-case
+ ASCII characters will collate together.
g\bgl\blo\bob\bbs\bsk\bki\bip\bpd\bdo\bot\bts\bs
- If set, pathname expansion will never match the file-
- names `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b', even if the pattern begins with
- a `\b``\b`.\b.'\b''\b'. This option is enabled by default.
+ If set, pathname expansion will never match the file-
+ names `\b``\b`.\b.'\b''\b' and `\b``\b`.\b..\b.'\b''\b', even if the pattern begins with
+ a `\b``\b`.\b.'\b''\b'. This option is enabled by default.
g\bgl\blo\bob\bbs\bst\bta\bar\br
If set, the pattern *\b**\b* 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 /\b/,
+ text will match all files and zero or more directories
+ and subdirectories. If the pattern is followed by a /\b/,
only directories and subdirectories match.
g\bgn\bnu\bu_\b_e\ber\brr\brf\bfm\bmt\bt
GNU error message format.
h\bhi\bis\bst\bta\bap\bpp\bpe\ben\bnd\bd
- If set, the history list is appended to the file named
+ If set, the history list is appended to the file named
by the value of the H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE variable when the shell ex-
its, rather than overwriting the file.
h\bhi\bis\bst\btr\bre\bee\bed\bdi\bit\bt
- If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, a user is given the
+ If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, a user is given the
opportunity to re-edit a failed history substitution.
h\bhi\bis\bst\btv\bve\ber\bri\bif\bfy\by
- If set, and r\bre\bea\bad\bdl\bli\bin\bne\be 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 r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer, allowing further modifica-
- tion.
+ If set, and r\bre\bea\bad\bdl\bli\bin\bne\be 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 r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer, allowing further modi-
+ fication.
h\bho\bos\bst\btc\bco\bom\bmp\bpl\ble\bet\bte\be
If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, b\bba\bas\bsh\bh will attempt to
- perform hostname completion when a word containing a @\b@
- is being completed (see C\bCo\bom\bmp\bpl\ble\bet\bti\bin\bng\bg under R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE in
- _\bb_\ba_\bs_\bh_\b(_\b1_\b)). This is enabled by default.
+ perform hostname completion when a word containing a @\b@
+ is being completed (see C\bCo\bom\bmp\bpl\ble\bet\bti\bin\bng\bg under R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE in
+ _\bb_\ba_\bs_\bh_\b(_\b1_\b)). This is enabled by default.
h\bhu\bup\bpo\bon\bne\bex\bxi\bit\bt
If set, b\bba\bas\bsh\bh will send S\bSI\bIG\bGH\bHU\bUP\bP to all jobs when an inter-
active login shell exits.
i\bin\bnh\bhe\ber\bri\bit\bt_\b_e\ber\brr\bre\bex\bxi\bit\bt
- If set, command substitution inherits the value of the
- e\ber\brr\bre\bex\bxi\bit\bt option, instead of unsetting it in the subshell
- environment. This option is enabled when _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be is
+ If set, command substitution inherits the value of the
+ e\ber\brr\bre\bex\bxi\bit\bt option, instead of unsetting it in the subshell
+ environment. This option is enabled when _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be is
enabled.
i\bin\bnt\bte\ber\bra\bac\bct\bti\biv\bve\be_\b_c\bco\bom\bmm\bme\ben\bnt\bts\bs
If set, allow a word beginning with #\b# to cause that word
- and all remaining characters on that line to be ignored
+ and all remaining characters on that line to be ignored
in an interactive shell (see C\bCO\bOM\bMM\bME\bEN\bNT\bTS\bS in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). This
option is enabled by default.
l\bla\bas\bst\btp\bpi\bip\bpe\be
- 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.
- l\bli\bit\bth\bhi\bis\bst\bt If set, and the c\bcm\bmd\bdh\bhi\bis\bst\bt option is enabled, multi-line
+ l\bli\bit\bth\bhi\bis\bst\bt If set, and the c\bcm\bmd\bdh\bhi\bis\bst\bt option is enabled, multi-line
commands are saved to the history with embedded newlines
rather than using semicolon separators where possible.
l\blo\boc\bca\bal\blv\bva\bar\br_\b_i\bin\bnh\bhe\ber\bri\bit\bt
If set, local variables inherit the value and attributes
of a variable of the same name that exists at a previous
- scope before any new value is assigned. The nameref at-
+ scope before any new value is assigned. The nameref at-
tribute is not inherited.
l\blo\boc\bca\bal\blv\bva\bar\br_\b_u\bun\bns\bse\bet\bt
- If set, calling u\bun\bns\bse\bet\bt on local variables in previous
- function scopes marks them so subsequent lookups find
- them unset until that function returns. This is identi-
- cal to the behavior of unsetting local variables at the
+ If set, calling u\bun\bns\bse\bet\bt on local variables in previous
+ function scopes marks them so subsequent lookups find
+ them unset until that function returns. This is identi-
+ cal to the behavior of unsetting local variables at the
current function scope.
l\blo\bog\bgi\bin\bn_\b_s\bsh\bhe\bel\bll\bl
- The shell sets this option if it is started as a login
- shell (see I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). The value may not be
+ The shell sets this option if it is started as a login
+ shell (see I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). The value may not be
changed.
m\bma\bai\bil\blw\bwa\bar\brn\bn
- If set, and a file that b\bba\bas\bsh\bh is checking for mail has
- been accessed since the last time it was checked, the
- message ``The mail in _\bm_\ba_\bi_\bl_\bf_\bi_\bl_\be has been read'' is dis-
+ If set, and a file that b\bba\bas\bsh\bh is checking for mail has
+ been accessed since the last time it was checked, the
+ message ``The mail in _\bm_\ba_\bi_\bl_\bf_\bi_\bl_\be has been read'' is dis-
played.
n\bno\bo_\b_e\bem\bmp\bpt\bty\by_\b_c\bcm\bmd\bd_\b_c\bco\bom\bmp\bpl\ble\bet\bti\bio\bon\bn
- If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, b\bba\bas\bsh\bh will not at-
- tempt to search the P\bPA\bAT\bTH\bH for possible completions when
+ If set, and r\bre\bea\bad\bdl\bli\bin\bne\be is being used, b\bba\bas\bsh\bh will not at-
+ tempt to search the P\bPA\bAT\bTH\bH for possible completions when
completion is attempted on an empty line.
n\bno\boc\bca\bas\bse\beg\bgl\blo\bob\bb
- If set, b\bba\bas\bsh\bh matches filenames in a case-insensitive
+ If set, b\bba\bas\bsh\bh matches filenames in a case-insensitive
fashion when performing pathname expansion (see P\bPa\bat\bth\bhn\bna\bam\bme\be
E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn in _\bb_\ba_\bs_\bh_\b(_\b1_\b)).
n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh
- If set, b\bba\bas\bsh\bh matches patterns in a case-insensitive
+ If set, b\bba\bas\bsh\bh matches patterns in a case-insensitive
fashion when performing matching while executing c\bca\bas\bse\be or
[\b[[\b[ conditional commands, when performing pattern substi-
- tution word expansions, or when filtering possible com-
+ tution word expansions, or when filtering possible com-
pletions as part of programmable completion.
n\bno\boe\bex\bxp\bpa\ban\bnd\bd_\b_t\btr\bra\ban\bns\bsl\bla\bat\bti\bio\bon\bn
- If set, b\bba\bas\bsh\bh encloses the translated results of $"..."
- quoting in single quotes instead of double quotes. If
+ If set, b\bba\bas\bsh\bh encloses the translated results of $"..."
+ quoting in single quotes instead of double quotes. If
the string is not translated, this has no effect.
n\bnu\bul\bll\blg\bgl\blo\bob\bb
- If set, b\bba\bas\bsh\bh allows patterns which match no files (see
- P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) to expand to a null
+ If set, b\bba\bas\bsh\bh allows patterns which match no files (see
+ P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) to expand to a null
string, rather than themselves.
p\bpa\bat\bts\bsu\bub\bb_\b_r\bre\bep\bpl\bla\bac\bce\bem\bme\ben\bnt\bt
If set, b\bba\bas\bsh\bh expands occurrences of &\b& in the replacement
- string of pattern substitution to the text matched by
- the pattern, as described under P\bPa\bar\bra\bam\bme\bet\bte\ber\br E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn in
- _\bb_\ba_\bs_\bh_\b(_\b1_\b). This option is enabled by default.
+ string of pattern substitution to the text matched by
+ the pattern, as described under P\bPa\bar\bra\bam\bme\bet\bte\ber\br E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn in
+ _\bb_\ba_\bs_\bh_\b(_\b1_\b). This option is enabled by default.
p\bpr\bro\bog\bgc\bco\bom\bmp\bp
If set, the programmable completion facilities (see P\bPr\bro\bo-\b-
- g\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) are enabled. This op-
+ g\bgr\bra\bam\bmm\bma\bab\bbl\ble\be C\bCo\bom\bmp\bpl\ble\bet\bti\bio\bon\bn in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) are enabled. This op-
tion is enabled by default.
p\bpr\bro\bog\bgc\bco\bom\bmp\bp_\b_a\bal\bli\bia\bas\bs
- If set, and programmable completion is enabled, b\bba\bas\bsh\bh
- treats a command name that doesn't have any completions
- as a possible alias and attempts alias expansion. If it
- has an alias, b\bba\bas\bsh\bh attempts programmable completion us-
+ If set, and programmable completion is enabled, b\bba\bas\bsh\bh
+ treats a command name that doesn't have any completions
+ as a possible alias and attempts alias expansion. If it
+ has an alias, b\bba\bas\bsh\bh attempts programmable completion us-
ing the command word resulting from the expanded alias.
p\bpr\bro\bom\bmp\bpt\btv\bva\bar\brs\bs
If set, prompt strings undergo parameter expansion, com-
- mand substitution, arithmetic expansion, and quote re-
- moval after being expanded as described in P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG in
- _\bb_\ba_\bs_\bh_\b(_\b1_\b). This option is enabled by default.
+ mand substitution, arithmetic expansion, and quote re-
+ moval after being expanded as described in P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG in
+ _\bb_\ba_\bs_\bh_\b(_\b1_\b). This option is enabled by default.
r\bre\bes\bst\btr\bri\bic\bct\bte\bed\bd_\b_s\bsh\bhe\bel\bll\bl
- The shell sets this option if it is started in re-
- stricted mode (see R\bRE\bES\bST\bTR\bRI\bIC\bCT\bTE\bED\bD S\bSH\bHE\bEL\bLL\bL in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). The
- value may not be changed. This is not reset when the
- startup files are executed, allowing the startup files
+ The shell sets this option if it is started in re-
+ stricted mode (see R\bRE\bES\bST\bTR\bRI\bIC\bCT\bTE\bED\bD S\bSH\bHE\bEL\bLL\bL in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). The
+ value may not be changed. This is not reset when the
+ startup files are executed, allowing the startup files
to discover whether or not a shell is restricted.
s\bsh\bhi\bif\bft\bt_\b_v\bve\ber\brb\bbo\bos\bse\be
- If set, the s\bsh\bhi\bif\bft\bt builtin prints an error message when
+ If set, the s\bsh\bhi\bif\bft\bt builtin prints an error message when
the shift count exceeds the number of positional parame-
ters.
s\bso\bou\bur\brc\bce\bep\bpa\bat\bth\bh
If set, the .\b. (s\bso\bou\bur\brc\bce\be) builtin uses the value of P\bPA\bAT\bTH\bH to
- find the directory containing the file supplied as an
- argument. This option is enabled by default.
+ find the directory containing the file supplied as an
+ argument. This option is enabled by default.
v\bva\bar\brr\bre\bed\bdi\bir\br_\b_c\bcl\blo\bos\bse\be
- If set, the shell automatically closes file descriptors
+ If set, the shell automatically closes file descriptors
assigned using the _\b{_\bv_\ba_\br_\bn_\ba_\bm_\be_\b} redirection syntax (see R\bRE\bE-\b-
- D\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) instead of leaving them open when
+ D\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN in _\bb_\ba_\bs_\bh_\b(_\b1_\b)) instead of leaving them open when
the command completes.
x\bxp\bpg\bg_\b_e\bec\bch\bho\bo
- If set, the e\bec\bch\bho\bo builtin expands backslash-escape se-
- quences by default. If the p\bpo\bos\bsi\bix\bx shell option is also
+ If set, the e\bec\bch\bho\bo builtin expands backslash-escape se-
+ quences by default. If the p\bpo\bos\bsi\bix\bx shell option is also
enabled, e\bec\bch\bho\bo does not interpret any options.
s\bsu\bus\bsp\bpe\ben\bnd\bd [-\b-f\bf]
- Suspend the execution of this shell until it receives a S\bSI\bIG\bGC\bCO\bON\bNT\bT
- signal. A login shell, or a shell without job control enabled,
- cannot be suspended; the -\b-f\bf option can be used to override this
- and force the suspension. The return status is 0 unless the
- shell is a login shell or job control is not enabled and -\b-f\bf is
+ Suspend the execution of this shell until it receives a S\bSI\bIG\bGC\bCO\bON\bNT\bT
+ signal. A login shell, or a shell without job control enabled,
+ cannot be suspended; the -\b-f\bf option can be used to override this
+ and force the suspension. The return status is 0 unless the
+ shell is a login shell or job control is not enabled and -\b-f\bf is
not supplied.
t\bte\bes\bst\bt _\be_\bx_\bp_\br
[\b[ _\be_\bx_\bp_\br ]\b]
Return a status of 0 (true) or 1 (false) depending on the evalu-
- ation of the conditional expression _\be_\bx_\bp_\br. Each operator and op-
- erand must be a separate argument. Expressions are composed of
- the primaries described in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bS-\b-
+ ation of the conditional expression _\be_\bx_\bp_\br. Each operator and op-
+ erand must be a separate argument. Expressions are composed of
+ the primaries described in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bS-\b-
S\bSI\bIO\bON\bNS\bS. t\bte\bes\bst\bt does not accept any options, nor does it accept and
ignore an argument of -\b--\b- as signifying the end of options.
- 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 precedence is
- used when there are five or more arguments.
+ Expressions may be combined using the following operators,
+ listed in decreasing order of precedence. The evaluation de-
+ pends on the number of arguments; see below. Operator prece-
+ dence is used when there are five or more arguments.
!\b! _\be_\bx_\bp_\br True if _\be_\bx_\bp_\br is false.
(\b( _\be_\bx_\bp_\br )\b)
- Returns the value of _\be_\bx_\bp_\br. This may be used to override
+ Returns the value of _\be_\bx_\bp_\br. This may be used to override
the normal precedence of operators.
_\be_\bx_\bp_\br_\b1 -a\ba _\be_\bx_\bp_\br_\b2
True if both _\be_\bx_\bp_\br_\b1 and _\be_\bx_\bp_\br_\b2 are true.
null.
2 arguments
If the first argument is !\b!, 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 in
- _\bb_\ba_\bs_\bh_\b(_\b1_\b) under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS, the expression is
- true if the unary test is true. If the first argument is
+ only if the second argument is null. If the first argu-
+ ment is one of the unary conditional operators listed in
+ _\bb_\ba_\bs_\bh_\b(_\b1_\b) under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bSS\bSI\bIO\bON\bNS\bS, 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
- operators listed in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bS-\b-
- S\bSI\bIO\bON\bNS\bS, the result of the expression is the result of the
- binary test using the first and third arguments as oper-
- ands. The -\b-a\ba and -\b-o\bo operators are considered binary oper-
- ators when there are three arguments. If the first argu-
- ment is !\b!, the value is the negation of the two-argument
- test using the second and third arguments. If the first
- argument is exactly (\b( and the third argument is exactly
- )\b), the result is the one-argument test of the second ar-
- gument. Otherwise, the expression is false.
+ If the second argument is one of the binary conditional
+ operators listed in _\bb_\ba_\bs_\bh_\b(_\b1_\b) under C\bCO\bON\bND\bDI\bIT\bTI\bIO\bON\bNA\bAL\bL E\bEX\bXP\bPR\bRE\bES\bS-\b-
+ S\bSI\bIO\bON\bNS\bS, the result of the expression is the result of the
+ binary test using the first and third arguments as oper-
+ ands. The -\b-a\ba and -\b-o\bo operators are considered binary op-
+ erators when there are three arguments. If the first ar-
+ gument is !\b!, the value is the negation of the two-argu-
+ ment test using the second and third arguments. If the
+ first argument is exactly (\b( and the third argument is ex-
+ actly )\b), the result is the one-argument test of the sec-
+ ond argument. Otherwise, the expression is false.
4 arguments
The following conditions are applied in the order listed.
If the first argument is !\b!, the result is the negation of
- the three-argument expression composed of the remaining
- arguments. the two-argument test using the second and
- third arguments. If the first argument is exactly (\b( and
- the fourth argument is exactly )\b), the result is the two-
- argument test of the second and third arguments. Other-
+ the three-argument expression composed of the remaining
+ arguments. the two-argument test using the second and
+ third arguments. If the first argument is exactly (\b( and
+ the fourth argument is exactly )\b), the result is the two-
+ argument test of the second and third arguments. Other-
wise, the expression is parsed and evaluated 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.
If the shell is not in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, when used with t\bte\bes\bst\bt or [\b[, the
- <\b< and >\b> operators sort lexicographically using ASCII ordering.
- When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, these operators sort using the
+ <\b< and >\b> operators sort lexicographically using ASCII ordering.
+ When the shell is in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, these operators sort using the
current locale.
- t\bti\bim\bme\bes\bs Print the accumulated user and system times for the shell and
- for processes run from the shell. The return status is 0.
+ t\bti\bim\bme\bes\bs Print the accumulated user and system times for the shell and
+ for processes run from the shell. The return status is 0.
t\btr\bra\bap\bp [-\b-l\blp\bp] [[_\ba_\bc_\bt_\bi_\bo_\bn] _\bs_\bi_\bg_\bs_\bp_\be_\bc ...]
The _\ba_\bc_\bt_\bi_\bo_\bn is a command that is read and executed when the shell
- receives signal(s) _\bs_\bi_\bg_\bs_\bp_\be_\bc. If _\ba_\bc_\bt_\bi_\bo_\bn is absent (and there is a
- single _\bs_\bi_\bg_\bs_\bp_\be_\bc) or -\b-, each specified signal is reset to its
- original disposition (the value it had upon entrance to the
- shell). If _\ba_\bc_\bt_\bi_\bo_\bn is the null string the signal specified by
- each _\bs_\bi_\bg_\bs_\bp_\be_\bc is ignored by the shell and by the commands it in-
+ receives signal(s) _\bs_\bi_\bg_\bs_\bp_\be_\bc. If _\ba_\bc_\bt_\bi_\bo_\bn is absent (and there is a
+ single _\bs_\bi_\bg_\bs_\bp_\be_\bc) or -\b-, each specified signal is reset to its
+ original disposition (the value it had upon entrance to the
+ shell). If _\ba_\bc_\bt_\bi_\bo_\bn is the null string the signal specified by
+ each _\bs_\bi_\bg_\bs_\bp_\be_\bc is ignored by the shell and by the commands it in-
vokes.
- If no arguments are supplied, t\btr\bra\bap\bp displays the actions associ-
+ If no arguments are supplied, t\btr\bra\bap\bp displays the actions associ-
ated with each trapped signal as a set of t\btr\bra\bap\bp commands that can
- be reused as shell input to restore the current signal disposi-
- tions. If -\b-p\bp is given, and _\ba_\bc_\bt_\bi_\bo_\bn is not present, then t\btr\bra\bap\bp dis-
- plays the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc or, if none are
- supplied, for all trapped signals, as a set of t\btr\bra\bap\bp commands
- that can be reused as shell input to restore the current signal
- dispositions. The -\b-P\bP option behaves similarly, but displays only
- the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. -\b-P\bP requires
- at least one _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. The -\b-P\bP or -\b-p\bp options to t\btr\bra\bap\bp may
- be used in a subshell environment (e.g., command substitution)
- and, as long as they are used before t\btr\bra\bap\bp is used to change a
- signal's handling, will display the state of its parent's traps.
+ be reused as shell input to restore the current signal disposi-
+ tions. If -\b-p\bp is given, and _\ba_\bc_\bt_\bi_\bo_\bn is not present, then t\btr\bra\bap\bp
+ displays the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc or, if none
+ are supplied, for all trapped signals, as a set of t\btr\bra\bap\bp commands
+ that can be reused as shell input to restore the current signal
+ dispositions. The -\b-P\bP option behaves similarly, but displays
+ only the actions associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. -\b-P\bP re-
+ quires at least one _\bs_\bi_\bg_\bs_\bp_\be_\bc argument. The -\b-P\bP or -\b-p\bp options to
+ t\btr\bra\bap\bp may be used in a subshell environment (e.g., command sub-
+ stitution) and, as long as they are used before t\btr\bra\bap\bp is used to
+ change a signal's handling, will display the state of its par-
+ ent's traps.
The -\b-l\bl option causes t\btr\bra\bap\bp to print a list of signal names and
- their corresponding numbers. Each _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a signal
- name defined in <_\bs_\bi_\bg_\bn_\ba_\bl_\b._\bh>, or a signal number. Signal names are
- case insensitive and the S\bSI\bIG\bG prefix is optional.
+ their corresponding numbers. Each _\bs_\bi_\bg_\bs_\bp_\be_\bc is either a signal
+ name defined in <_\bs_\bi_\bg_\bn_\ba_\bl_\b._\bh>, or a signal number. Signal names
+ are case insensitive and the S\bSI\bIG\bG prefix is optional.
If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is E\bEX\bXI\bIT\bT (0) the command _\ba_\bc_\bt_\bi_\bo_\bn is executed on exit
- from the shell. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is D\bDE\bEB\bBU\bUG\bG, the command _\ba_\bc_\bt_\bi_\bo_\bn is ex-
- ecuted before every _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, _\bf_\bo_\br command, _\bc_\ba_\bs_\be command,
+ from the shell. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is D\bDE\bEB\bBU\bUG\bG, the command _\ba_\bc_\bt_\bi_\bo_\bn is
+ executed before every _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd, _\bf_\bo_\br command, _\bc_\ba_\bs_\be command,
_\bs_\be_\bl_\be_\bc_\bt command, (( arithmetic command, [[ conditional command,
arithmetic _\bf_\bo_\br command, and before the first command executes in
a shell function (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR in _\bb_\ba_\bs_\bh_\b(_\b1_\b)). Refer to the
description of the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the s\bsh\bho\bop\bpt\bt builtin for de-
- tails of its effect on the D\bDE\bEB\bBU\bUG\bG trap. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is R\bRE\bET\bTU\bUR\bRN\bN,
+ tails of its effect on the D\bDE\bEB\bBU\bUG\bG trap. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is R\bRE\bET\bTU\bUR\bRN\bN,
the command _\ba_\bc_\bt_\bi_\bo_\bn is executed each time a shell function or a
script executed with the .\b. or s\bso\bou\bur\brc\bce\be builtins finishes execut-
ing.
If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is E\bER\bRR\bR, the command _\ba_\bc_\bt_\bi_\bo_\bn is executed whenever a
pipeline (which may consist of a single simple command), a list,
or a compound command returns a non-zero exit status, subject to
- the following conditions. The E\bER\bRR\bR trap is not executed if the
+ the following conditions. The E\bER\bRR\bR trap is not executed if the
failed command is part of the command list immediately following
a w\bwh\bhi\bil\ble\be or u\bun\bnt\bti\bil\bl keyword, part of the test in an _\bi_\bf statement,
part of a command executed in a &\b&&\b& or |\b||\b| list except the command
following the final &\b&&\b& or |\b||\b|, any command in a pipeline but the
last, or if the command's return value is being inverted using
- !\b!. These are the same conditions obeyed by the e\ber\brr\bre\bex\bxi\bit\bt (-\b-e\be) op-
+ !\b!. These are the same conditions obeyed by the e\ber\brr\bre\bex\bxi\bit\bt (-\b-e\be) op-
tion.
When the shell is not interactive, signals ignored upon entry to
- the shell cannot be trapped or reset. Interactive shells permit
- trapping signals ignored on entry. Trapped signals that are not
+ the shell cannot be trapped or reset. Interactive shells permit
+ trapping signals ignored on entry. 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
+ or subshell environment when one is created. The return status
is false if any _\bs_\bi_\bg_\bs_\bp_\be_\bc is invalid; otherwise t\btr\bra\bap\bp returns true.
t\btr\bru\bue\be Does nothing, returns a 0 status.
t\bty\byp\bpe\be [-\b-a\baf\bft\btp\bpP\bP] _\bn_\ba_\bm_\be [_\bn_\ba_\bm_\be ...]
With no options, indicate how each _\bn_\ba_\bm_\be would be interpreted if
- used as a command name. If the -\b-t\bt option is used, t\bty\byp\bpe\be prints a
+ used as a command name. If the -\b-t\bt option is used, t\bty\byp\bpe\be prints a
string which is one of _\ba_\bl_\bi_\ba_\bs, _\bk_\be_\by_\bw_\bo_\br_\bd, _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn, _\bb_\bu_\bi_\bl_\bt_\bi_\bn, or
_\bf_\bi_\bl_\be if _\bn_\ba_\bm_\be is an alias, shell reserved word, function,
- builtin, or executable disk file, respectively. If the _\bn_\ba_\bm_\be is
+ builtin, or executable disk file, respectively. If the _\bn_\ba_\bm_\be is
not found, then nothing is printed, and t\bty\byp\bpe\be returns a non-zero
- exit status. If the -\b-p\bp option is used, t\bty\byp\bpe\be either returns the
+ exit status. If the -\b-p\bp option is used, t\bty\byp\bpe\be either returns the
name of the executable file that would be found by searching
$\b$P\bPA\bAT\bTH\bH if _\bn_\ba_\bm_\be were specified as a command name, or nothing if
- ``type -t name'' would not return _\bf_\bi_\bl_\be. The -\b-P\bP option forces a
+ ``type -t name'' would not return _\bf_\bi_\bl_\be. The -\b-P\bP option forces a
P\bPA\bAT\bTH\bH search for each _\bn_\ba_\bm_\be, even if ``type -t name'' would not
- return _\bf_\bi_\bl_\be. If a command is hashed, -\b-p\bp and -\b-P\bP print the hashed
+ return _\bf_\bi_\bl_\be. If a command is hashed, -\b-p\bp and -\b-P\bP print the hashed
value, which is not necessarily the file that appears first in
- P\bPA\bAT\bTH\bH. If the -\b-a\ba option is used, t\bty\byp\bpe\be prints all of the places
- that contain a command named _\bn_\ba_\bm_\be. This includes aliases, re-
+ P\bPA\bAT\bTH\bH. If the -\b-a\ba option is used, t\bty\byp\bpe\be prints all of the places
+ that contain a command named _\bn_\ba_\bm_\be. This includes aliases, re-
served words, functions, and builtins, but the path search op-
tions (-\b-p\bp and -\b-P\bP) can be supplied to restrict the output to exe-
- cutable files. t\bty\byp\bpe\be does not consult the table of hashed com-
+ cutable files. t\bty\byp\bpe\be does not consult the table of hashed com-
mands when using -\b-a\ba with -\b-p\bp, and only performs a P\bPA\bAT\bTH\bH search for
- _\bn_\ba_\bm_\be. The -\b-f\bf option suppresses shell function lookup, as with
- the c\bco\bom\bmm\bma\ban\bnd\bd builtin. t\bty\byp\bpe\be returns true if all of the arguments
+ _\bn_\ba_\bm_\be. The -\b-f\bf option suppresses shell function lookup, as with
+ the c\bco\bom\bmm\bma\ban\bnd\bd builtin. t\bty\byp\bpe\be returns true if all of the arguments
are found, false if any are not found.
u\bul\bli\bim\bmi\bit\bt [-\b-H\bHS\bS] -\b-a\ba
Provides control over the resources available to the shell and
to processes started by it, on systems that allow such control.
The -\b-H\bH and -\b-S\bS options specify that the hard or soft limit is set
- for the given resource. A hard limit cannot be increased by a
+ 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 -\b-H\bH nor -\b-S\bS is speci-
- fied, both the soft and hard limits are set. The value of _\bl_\bi_\bm_\bi_\bt
+ to the value of the hard limit. If neither -\b-H\bH nor -\b-S\bS is speci-
+ fied, both the soft and hard limits are set. The value of _\bl_\bi_\bm_\bi_\bt
can be a number in the unit specified for the resource or one of
the special values h\bha\bar\brd\bd, s\bso\bof\bft\bt, or u\bun\bnl\bli\bim\bmi\bit\bte\bed\bd, which stand for the
current hard limit, the current soft limit, and no limit, re-
- spectively. If _\bl_\bi_\bm_\bi_\bt is omitted, the current value of the soft
+ spectively. If _\bl_\bi_\bm_\bi_\bt is omitted, the current value of the soft
limit of the resource is printed, unless the -\b-H\bH option is given.
When more than one resource is specified, the limit name and
- unit, if appropriate, are printed before the value. Other op-
+ unit, if appropriate, are printed before the value. Other op-
tions are interpreted as follows:
-\b-a\ba All current limits are reported; no limits are set
-\b-b\bb The maximum socket buffer size
-\b-T\bT The maximum number of threads
If _\bl_\bi_\bm_\bi_\bt is given, and the -\b-a\ba option is not used, _\bl_\bi_\bm_\bi_\bt is the
- new value of the specified resource. If no option is given, then
- -\b-f\bf is assumed. Values are in 1024-byte increments, except for
- -\b-t\bt, which is in seconds; -\b-R\bR, which is in microseconds; -\b-p\bp, which
- is in units of 512-byte blocks; -\b-P\bP, -\b-T\bT, -\b-b\bb, -\b-k\bk, -\b-n\bn, and -\b-u\bu,
- which are unscaled values; and, when in posix mode, -\b-c\bc and -\b-f\bf,
- which are in 512-byte increments. The return status is 0 unless
- an invalid option or argument is supplied, or an error occurs
- while setting a new limit.
+ new value of the specified resource. If no option is given,
+ then -\b-f\bf is assumed. Values are in 1024-byte increments, except
+ for -\b-t\bt, which is in seconds; -\b-R\bR, which is in microseconds; -\b-p\bp,
+ which is in units of 512-byte blocks; -\b-P\bP, -\b-T\bT, -\b-b\bb, -\b-k\bk, -\b-n\bn, and
+ -\b-u\bu, which are unscaled values; and, when in posix mode, -\b-c\bc and
+ -\b-f\bf, which are in 512-byte increments. The return status is 0
+ unless an invalid option or argument is supplied, or an error
+ occurs while setting a new limit.
u\bum\bma\bas\bsk\bk [-\b-p\bp] [-\b-S\bS] [_\bm_\bo_\bd_\be]
- The user file-creation mask is set to _\bm_\bo_\bd_\be. If _\bm_\bo_\bd_\be begins with
+ The user file-creation mask is set to _\bm_\bo_\bd_\be. If _\bm_\bo_\bd_\be 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
- _\bc_\bh_\bm_\bo_\bd(1). If _\bm_\bo_\bd_\be is omitted, the current value of the mask is
- printed. The -\b-S\bS option causes the mask to be printed in symbolic
- form; the default output is an octal number. If the -\b-p\bp option is
- supplied, and _\bm_\bo_\bd_\be is omitted, the output is in a form that may
- be reused as input. The return status is 0 if the mode was suc-
- cessfully changed or if no _\bm_\bo_\bd_\be argument was supplied, and false
- otherwise.
+ _\bc_\bh_\bm_\bo_\bd(1). If _\bm_\bo_\bd_\be is omitted, the current value of the mask is
+ printed. The -\b-S\bS option causes the mask to be printed in sym-
+ bolic form; the default output is an octal number. If the -\b-p\bp
+ option is supplied, and _\bm_\bo_\bd_\be 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 _\bm_\bo_\bd_\be argument was supplied,
+ and false otherwise.
u\bun\bna\bal\bli\bia\bas\bs [-a\ba] [_\bn_\ba_\bm_\be ...]
- Remove each _\bn_\ba_\bm_\be from the list of defined aliases. If -\b-a\ba is sup-
- plied, all alias definitions are removed. The return value is
- true unless a supplied _\bn_\ba_\bm_\be is not a defined alias.
+ Remove each _\bn_\ba_\bm_\be from the list of defined aliases. If -\b-a\ba is
+ supplied, all alias definitions are removed. The return value
+ is true unless a supplied _\bn_\ba_\bm_\be is not a defined alias.
u\bun\bns\bse\bet\bt [-f\bfv\bv] [-n\bn] [_\bn_\ba_\bm_\be ...]
- For each _\bn_\ba_\bm_\be, remove the corresponding variable or function. If
- the -\b-v\bv option is given, each _\bn_\ba_\bm_\be refers to a shell variable,
- and that variable is removed. Read-only variables may not be un-
- set. If -\b-f\bf is specified, each _\bn_\ba_\bm_\be refers to a shell function,
- and the function definition is removed. If the -\b-n\bn option is sup-
- plied, and _\bn_\ba_\bm_\be is a variable with the _\bn_\ba_\bm_\be_\br_\be_\bf attribute, _\bn_\ba_\bm_\be
- will be unset rather than the variable it references. -\b-n\bn has no
- effect if the -\b-f\bf option is supplied. If no options are supplied,
- each _\bn_\ba_\bm_\be refers to a variable; if there is no variable by that
- name, a function with that name, if any, is unset. Each unset
- variable or function is removed from the environment passed to
- subsequent commands. If any of B\bBA\bAS\bSH\bH_\b_A\bAL\bLI\bIA\bAS\bSE\bES\bS, B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0,
- B\bBA\bAS\bSH\bH_\b_C\bCM\bMD\bDS\bS, B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD, B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL, B\bBA\bAS\bSH\bHP\bPI\bID\bD, C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bD-\b-
- B\bBR\bRE\bEA\bAK\bKS\bS, D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK, E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE, E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS, F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE, G\bGR\bRO\bOU\bUP\bPS\bS,
- H\bHI\bIS\bST\bTC\bCM\bMD\bD, L\bLI\bIN\bNE\bEN\bNO\bO, R\bRA\bAN\bND\bDO\bOM\bM, S\bSE\bEC\bCO\bON\bND\bDS\bS, or S\bSR\bRA\bAN\bND\bDO\bOM\bM are unset, they
- lose their special properties, even if they are subsequently re-
- set. The exit status is true unless a _\bn_\ba_\bm_\be is readonly or may
- not be unset.
+ For each _\bn_\ba_\bm_\be, remove the corresponding variable or function.
+ If the -\b-v\bv option is given, each _\bn_\ba_\bm_\be refers to a shell variable,
+ and that variable is removed. Read-only variables may not be
+ unset. If -\b-f\bf is specified, each _\bn_\ba_\bm_\be refers to a shell func-
+ tion, and the function definition is removed. If the -\b-n\bn option
+ is supplied, and _\bn_\ba_\bm_\be is a variable with the _\bn_\ba_\bm_\be_\br_\be_\bf attribute,
+ _\bn_\ba_\bm_\be will be unset rather than the variable it references. -\b-n\bn
+ has no effect if the -\b-f\bf option is supplied. If no options are
+ supplied, each _\bn_\ba_\bm_\be refers to a variable; if there is no vari-
+ able by that name, a function with that name, if any, is unset.
+ Each unset variable or function is removed from the environment
+ passed to subsequent commands. If any of B\bBA\bAS\bSH\bH_\b_A\bAL\bLI\bIA\bAS\bSE\bES\bS,
+ B\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV0\b0, B\bBA\bAS\bSH\bH_\b_C\bCM\bMD\bDS\bS, B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD, B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL, B\bBA\bAS\bSH\bHP\bPI\bID\bD,
+ C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS, D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK, E\bEP\bPO\bOC\bCH\bHR\bRE\bEA\bAL\bLT\bTI\bIM\bME\bE, E\bEP\bPO\bOC\bCH\bHS\bSE\bEC\bCO\bON\bND\bDS\bS, F\bFU\bUN\bNC\bC-\b-
+ N\bNA\bAM\bME\bE, G\bGR\bRO\bOU\bUP\bPS\bS, H\bHI\bIS\bST\bTC\bCM\bMD\bD, L\bLI\bIN\bNE\bEN\bNO\bO, R\bRA\bAN\bND\bDO\bOM\bM, S\bSE\bEC\bCO\bON\bND\bDS\bS, or S\bSR\bRA\bAN\bND\bDO\bOM\bM are
+ unset, they lose their special properties, even if they are sub-
+ sequently reset. The exit status is true unless a _\bn_\ba_\bm_\be is read-
+ only or may not be unset.
w\bwa\bai\bit\bt [-\b-f\bfn\bn] [-\b-p\bp _\bv_\ba_\br_\bn_\ba_\bm_\be] [_\bi_\bd _\b._\b._\b.]
Wait for each specified child process and return its termination
- status. Each _\bi_\bd 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 _\bi_\bd is not given, w\bwa\bai\bit\bt waits for all running back-
- ground jobs and the last-executed process substitution, if its
- process id is the same as $\b$!\b!, and the return status is zero. If
- the -\b-n\bn option is supplied, w\bwa\bai\bit\bt waits for a single job from the
- list of _\bi_\bds or, if no _\bi_\bds are supplied, any job, to complete and
- returns its exit status. If none of the supplied arguments is a
- child of the shell, or if no arguments are supplied and the
- shell has no unwaited-for children, the exit status is 127. If
+ status. Each _\bi_\bd 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 _\bi_\bd is not given, w\bwa\bai\bit\bt waits for all running
+ background jobs and the last-executed process substitution, if
+ its process id is the same as $\b$!\b!, and the return status is zero.
+ If the -\b-n\bn option is supplied, w\bwa\bai\bit\bt waits for a single job from
+ the list of _\bi_\bds or, if no _\bi_\bds are supplied, any job, to complete
+ and returns its exit status. If none of the supplied arguments
+ is a child of the shell, or if no arguments are supplied and the
+ shell has no unwaited-for children, the exit status is 127. If
the -\b-p\bp option is supplied, the process or job identifier of the
job for which the exit status is returned is assigned to the
- variable _\bv_\ba_\br_\bn_\ba_\bm_\be named by the option argument. The variable will
- be unset initially, before any assignment. This is useful only
- when the -\b-n\bn option is supplied. Supplying the -\b-f\bf option, when
- job control is enabled, forces w\bwa\bai\bit\bt to wait for _\bi_\bd to terminate
- before returning its status, instead of returning when it
+ variable _\bv_\ba_\br_\bn_\ba_\bm_\be named by the option argument. The variable
+ will be unset initially, before any assignment. This is useful
+ only when the -\b-n\bn option is supplied. Supplying the -\b-f\bf option,
+ when job control is enabled, forces w\bwa\bai\bit\bt to wait for _\bi_\bd to ter-
+ minate before returning its status, instead of returning when it
changes status. If _\bi_\bd specifies a non-existent process or job,
- the return status is 127. If w\bwa\bai\bit\bt is interrupted by a signal,
+ the return status is 127. If w\bwa\bai\bit\bt is interrupted by a signal,
the return status will be greater than 128, as described under
- S\bSI\bIG\bGN\bNA\bAL\bLS\bS in _\bb_\ba_\bs_\bh_\b(_\b1_\b). Otherwise, the return status is the exit
+ S\bSI\bIG\bGN\bNA\bAL\bLS\bS in _\bb_\ba_\bs_\bh_\b(_\b1_\b). Otherwise, the return status is the exit
status of the last process or job waited for.
S\bSH\bHE\bEL\bLL\bL C\bCO\bOM\bMP\bPA\bAT\bTI\bIB\bBI\bIL\bLI\bIT\bTY\bY M\bMO\bOD\bDE\bE
Bash-4.0 introduced the concept of a _\bs_\bh_\be_\bl_\bl _\bc_\bo_\bm_\bp_\ba_\bt_\bi_\bb_\bi_\bl_\bi_\bt_\by _\bl_\be_\bv_\be_\bl, speci-
fied as a set of options to the shopt builtin ( c\bco\bom\bmp\bpa\bat\bt3\b31\b1, c\bco\bom\bmp\bpa\bat\bt3\b32\b2,
- c\bco\bom\bmp\bpa\bat\bt4\b40\b0, c\bco\bom\bmp\bpa\bat\bt4\b41\b1, and so on). There is only one current compatibility
- level - each option is mutually exclusive. The compatibility level is
- intended to allow users to select behavior from previous versions that
- is incompatible with newer versions while they migrate scripts to use
- current features and behavior. It's intended to be a temporary solu-
- tion.
+ c\bco\bom\bmp\bpa\bat\bt4\b40\b0, c\bco\bom\bmp\bpa\bat\bt4\b41\b1, and so on). There is only one current compatibil-
+ ity level -- each option is mutually exclusive. The compatibility
+ level is intended to allow users to select behavior from previous ver-
+ sions that is incompatible with newer versions while they migrate
+ scripts to use current features and behavior. It's intended to be a
+ temporary solution.
This section does not mention behavior that is standard for a particu-
lar version (e.g., setting c\bco\bom\bmp\bpa\bat\bt3\b32\b2 means that quoting the rhs of the
If a user enables, say, c\bco\bom\bmp\bpa\bat\bt3\b32\b2, it may affect the behavior of other
compatibility levels up to and including the current compatibility
- level. The idea is that each compatibility level controls behavior that
- changed in that version of b\bba\bas\bsh\bh, but that behavior may have been
- present in earlier versions. For instance, the change to use locale-
+ level. The idea is that each compatibility level controls behavior
+ that changed in that version of b\bba\bas\bsh\bh, but that behavior may have been
+ present in earlier versions. For instance, the change to use locale-
based comparisons with the [\b[[\b[ command came in bash-4.1, and earlier
versions used ASCII-based comparisons, so enabling c\bco\bom\bmp\bpa\bat\bt3\b32\b2 will enable
- ASCII-based comparisons as well. That granularity may not be sufficient
- for all uses, and as a result users should employ compatibility levels
- carefully. Read the documentation for a particular feature to find out
- the current behavior.
+ ASCII-based comparisons as well. That granularity may not be suffi-
+ cient for all uses, and as a result users should employ compatibility
+ levels carefully. Read the documentation for a particular feature to
+ find out the current behavior.
- Bash-4.3 introduced a new shell variable: B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT. The value as-
+ Bash-4.3 introduced a new shell variable: B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT. The value as-
signed to this variable (a decimal version number like 4.2, or an inte-
ger corresponding to the c\bco\bom\bmp\bpa\bat\bt_\bN_\bN option, like 42) determines the com-
patibility level.
Starting with bash-4.4, b\bba\bas\bsh\bh has begun deprecating older compatibility
- levels. Eventually, the options will be removed in favor of B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bM-\b-
+ levels. Eventually, the options will be removed in favor of B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bM-\b-
P\bPA\bAT\bT.
Bash-5.0 is the final version for which there will be an individual
bash-5.0 and later versions.
The following table describes the behavior changes controlled by each
- compatibility level setting. The c\bco\bom\bmp\bpa\bat\bt_\bN_\bN tag is used as shorthand for
+ compatibility level setting. The c\bco\bom\bmp\bpa\bat\bt_\bN_\bN tag is used as shorthand for
setting the compatibility level to _\bN_\bN using one of the following mecha-
- nisms. For versions prior to bash-5.0, the compatibility level may be
- set using the corresponding c\bco\bom\bmp\bpa\bat\bt_\bN_\bN shopt option. For bash-4.3 and
+ nisms. For versions prior to bash-5.0, the compatibility level may be
+ set using the corresponding c\bco\bom\bmp\bpa\bat\bt_\bN_\bN shopt option. For bash-4.3 and
later versions, the B\bBA\bAS\bSH\bH_\b_C\bCO\bOM\bMP\bPA\bAT\bT variable is preferred, and it is re-
quired for bash-5.1 and later versions.
can be expanded more than once
+\bo t\bte\bes\bst\bt -\b-v\bv, when given an argument of A\bA[\b[@\b@]\b], where A\bAP\bP i\bis\bs a\ban\bn
e\bex\bxi\bis\bst\bti\bin\bng\bg a\bas\bss\bso\boc\bci\bia\bat\bti\biv\bve\be a\bar\brr\bra\bay\by,\b, w\bwi\bil\bll\bl r\bre\bet\btu\bur\brn\bn t\btr\bru\bue\be i\bif\bf t\bth\bhe\be a\bar\brr\bra\bay\by
- h\bha\bas\bs a\ban\bny\by s\bse\bet\bt e\bel\ble\bem\bme\ben\bnt\bts\bs.\b. B\bBa\bas\bsh\bh-\b-5\b5.\b.2\b2 w\bwi\bil\bll\bl l\blo\boo\bok\bk f\bfo\bor\br a\ban\bnd\bd r\bre\bep\bpo\bor\brt\bt
+ h\bha\bas\bs a\ban\bny\by s\bse\bet\bt e\bel\ble\bem\bme\ben\bnt\bts\bs.\b. B\bBa\bas\bsh\bh-\b-5\b5.\b.2\b2 w\bwi\bil\bll\bl l\blo\boo\bok\bk f\bfo\bor\br a\ban\bnd\bd r\bre\bep\bpo\bor\brt\bt
o\bon\bn a\ba k\bke\bey\by n\bna\bam\bme\bed\bd @\b@.\b.
+\b+\bo\bo the ${_\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br[\b[:\b:]\b]=\b=_\bv_\ba_\bl_\bu_\be} word expansion will return
_\bv_\ba_\bl_\bu_\be, before any variable-specific transformations have
globbing (see the description of the s\bsh\bho\bop\bpt\bt builtin above)
is enabled, so that parsing a command substitution con-
taining an extglob pattern (say, as part of a shell func-
- tion) will not fail. This assumes the intent is to enable
- extglob before the command is executed and word expan-
- sions are performed. It will fail at word expansion time
- if extglob hasn't been enabled by the time the command is
- executed.
+ tion) will not fail. This assumes the intent is to en-
+ able extglob before the command is executed and word ex-
+ pansions are performed. It will fail at word expansion
+ time if extglob hasn't been enabled by the time the com-
+ mand is executed.
S\bSE\bEE\bE A\bAL\bLS\bSO\bO
bash(1), sh(1)
projects / thirdparty / bash.git / commitdiff
