-BASH(1) BASH(1)
+BASH(1) General Commands Manual BASH(1)
bash - GNU Bourne-Again SHell
S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
- b\bba\bas\bsh\bh [options] [file]
+ b\bba\bas\bsh\bh [options] [command_string | file]
C\bCO\bOP\bPY\bYR\bRI\bIG\bGH\bHT\bT
- Bash is Copyright (C) 1989-2009 by the Free Software Foundation, Inc.
+ Bash is Copyright (C) 1989-2016 by the Free Software Foundation, Inc.
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
1003.1). B\bBa\bas\bsh\bh can be configured to be POSIX-conformant by default.
O\bOP\bPT\bTI\bIO\bON\bNS\bS
- In addition to the single-character shell options documented in the
- description of the s\bse\bet\bt builtin command, b\bba\bas\bsh\bh interprets the following
- options when it is invoked:
-
- -\b-c\bc _\bs_\bt_\br_\bi_\bn_\bg If the -\b-c\bc option is present, then commands are read from
- _\bs_\bt_\br_\bi_\bn_\bg. If there are arguments after the _\bs_\bt_\br_\bi_\bn_\bg, they are
- assigned to the positional parameters, starting with $\b$0\b0.
+ All of the single-character shell options documented in the description
+ of the s\bse\bet\bt builtin command can be used as options when the shell is
+ invoked. In addition, b\bba\bas\bsh\bh interprets the following options 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-
+ ments after the _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b__\bs_\bt_\br_\bi_\bn_\bg, the first argument is
+ assigned to $\b$0\b0 and any remaining arguments are assigned to
+ the positional parameters. The assignment to $\b$0\b0 sets the
+ name of the shell, which is used in warning and error mes-
+ sages.
-\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
I\bIN\bNV\bVO\bOC\bCA\bAT\bTI\bIO\bON\bN below).
- -\b-r\br If the -\b-r\br option is present, the shell becomes _\br_\be_\bs_\bt_\br_\bi_\bc_\bt_\be_\bd
+ -\b-r\br If the -\b-r\br option is present, the shell becomes _\br_\be_\bs_\bt_\br_\bi_\bc_\bt_\be_\bd
(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
+ -\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.
- -\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-
+ -\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-
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
+ 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
+ _\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
_\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
- 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
- output is displayed in a format that may be reused as input.
+ 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
+ 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-.
-\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) and shell
- function tracing (see the description of the -\b-o\bo f\bfu\bun\bnc\bct\btr\bra\bac\bce\be option
- to the s\bse\bet\bt builtin below).
+ 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-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).
+ 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.
-\b--\b-r\bre\bes\bst\btr\bri\bic\bct\bte\bed\bd
The shell becomes restricted (see R\bRE\bES\bST\bTR\bRI\bIC\bCT\bTE\bED\bD S\bSH\bHE\bEL\bLL\bL below).
-\b--\b-v\bve\ber\brb\bbo\bos\bse\be
- Equivalent to -\b-v\bv.
+ 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-
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 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.
+ An _\bi_\bn_\bt_\be_\br_\ba_\bc_\bt_\bi_\bv_\be shell is one started without non-option arguments
+ (unless -\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.
- 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 file names 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 a login shell exits, 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 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
+ 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
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
startup files are read.
B\bBa\bas\bsh\bh attempts to determine when it is being run with its standard input
- connected to a a network connection, as if by the 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 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 _\br_\bs_\bh_\bd does not generally invoke the shell with those options or
- allow them to be specified.
+ connected to a network connection, as when executed by the remote shell
+ daemon, usually _\br_\bs_\bh_\bd, or the secure shell daemon _\bs_\bs_\bh_\bd. If b\bba\bas\bsh\bh deter-
+ mines it is being run 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 variable, if it appears in the environment, is 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.
+ 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
+ appear 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
+ 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-
+ 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
+ |\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-
lowing symbols:
- |\b||\b| &\b& &\b&&\b& ;\b; ;\b;;\b; (\b( )\b) |\b| |\b|&\b& <\b<n\bne\bew\bwl\bli\bin\bne\be>\b>
+ |\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
following words are recognized as reserved when unquoted and either the
- first word of a simple command (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR below) or the third
+ first word of a simple command (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR below) or the third
word of a c\bca\bas\bse\be or f\bfo\bor\br command:
- !\b! c\bca\bas\bse\be 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]
+ !\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
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
+ 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
+ and is passed as argument zero. The remaining words are passed as
arguments 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
+ 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 [ [|\b|||\b|&\b&] _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2 ... ]
- The standard output of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is connected via a pipe to the standard
- input of _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2. This connection is performed before any redirec-
+ The standard output of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is connected via a pipe to the standard
+ input of _\bc_\bo_\bm_\bm_\ba_\bn_\bd_\b2. This connection is performed before any redirec-
tions specified by the command (see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below). If |\b|&\b& is used,
- the standard error of _\bc_\bo_\bm_\bm_\ba_\bn_\bd is connected 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 redirect-
- ion of the standard error is performed after any redirections specified
- by the command.
+ _\bc_\bo_\bm_\bm_\ba_\bn_\bd'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 the
+ command.
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
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. 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.
-
- Each command in a pipeline is executed as a separate process (i.e., in
+ 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 may be used to
+ specify the format of the time information.
+
+ Each command in a pipeline is executed as a separate process (i.e., in
a subshell).
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. 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
+ 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. 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 executed.
- AND and OR lists are sequences of one of more pipelines separated by
- the &\b&&\b& and |\b||\b| control operators, respectively. AND and OR lists are
+ AND and OR lists are sequences of one of 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.
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
+ _\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:
+ 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 environment (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 below). Variable assignments and builtin com-
tional operators such as -\b-f\bf must be unquoted to be recognized as
primaries.
- When the =\b==\b= and !\b!=\b= operators are used, the string to the right
+ 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
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. If the shell
- option n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh 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 pat-
- tern, and 1 otherwise. Any part of the pattern may be quoted to
- force it 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 an extended regular expres-
+ 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 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 an extended regular expres-
sion and matched accordingly (as 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 conditional
- expression's return value is 2. If the shell option n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh
+ regular expression is syntactically incorrect, the conditional
+ 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. Any part of the pattern may be quoted to
- force it to be matched as a string. Substrings matched by
- parenthesized subexpressions within the regular expression are
- saved in the array variable B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH. The element of
- B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH with index 0 is the portion of the string matching
- the entire regular expression. 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 parenthe-
- sized subexpression.
-
- Expressions may be combined using the following operators,
+ force the quoted portion to be matched as a string. Bracket
+ expressions in regular expressions must be treated carefully,
+ since normal quoting characters lose their meanings between
+ brackets. If the pattern is stored in a shell variable, quoting
+ the variable expansion forces the entire pattern to be matched
+ as a string. Substrings matched by parenthesized subexpressions
+ within the regular expression are saved in the array variable
+ B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH. The element of B\bBA\bAS\bSH\bH_\b_R\bRE\bEM\bMA\bAT\bTC\bCH\bH with index 0 is the
+ portion of the string matching the entire regular expression.
+ 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.
+
+ Expressions may be combined using the following operators,
listed in decreasing order of precedence:
(\b( _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn )\b)
- Returns the value of _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn. This may be used to
+ Returns the value of _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn. This may be used to
override the normal precedence of operators.
!\b! _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn
True if _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn is false.
True if either _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn_\b1 or _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn_\b2 is true.
The &\b&&\b& and |\b||\b| operators do not evaluate _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn_\b2 if the value
- of _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn_\b1 is sufficient to determine the return value of
+ of _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn_\b1 is sufficient to determine the return value of
the entire conditional expression.
- f\bfo\bor\br _\bn_\ba_\bm_\be [ i\bin\bn _\bw_\bo_\br_\bd ] ; d\bdo\bo _\bl_\bi_\bs_\bt ; d\bdo\bon\bne\be
+ 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 omit-
- ted, the f\bfo\bor\br command executes _\bl_\bi_\bs_\bt once for each positional
+ 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
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
+ 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
- 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
- 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
+ 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
+ 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
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. 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).
- The P\bPS\bS3\b3 prompt is then displayed and a line read from the stan-
- dard input. If the line consists of a number corresponding to
- one of the displayed words, then the value of _\bn_\ba_\bm_\be is set to
- that word. If the line is empty, the words and prompt are dis-
+ items. The set of expanded words is printed on the standard
+ error, each preceded by a number. If the 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).
+ The P\bPS\bS3\b3 prompt is then displayed and a line read from the stan-
+ dard input. If the line consists of a number corresponding to
+ one of the displayed words, then the value of _\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 command completes. 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
+ 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
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,
+ 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 same matching rules as for path-
- name expansion (see P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn below). The _\bw_\bo_\br_\bd is
- expanded using tilde expansion, parameter and variable expan-
- sion, arithmetic substitution, command substitution, process
- substitution and quote removal. Each _\bp_\ba_\bt_\bt_\be_\br_\bn examined is
+ name expansion (see P\bPa\bat\bth\bhn\bna\bam\bme\be E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn below). The _\bw_\bo_\br_\bd is
expanded using tilde expansion, parameter and variable expan-
- sion, arithmetic substitution, command substitution, and process
- substitution. If the shell option n\bno\boc\bca\bas\bse\bem\bma\bat\btc\bch\bh is enabled, the
- match is performed without 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 pattern 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. 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_\b; [ 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
+ sion, arithmetic expansion, command substitution, process sub-
+ stitution and quote removal. Each _\bp_\ba_\bt_\bt_\be_\br_\bn examined is expanded
+ using tilde expansion, parameter and variable expansion, arith-
+ metic expansion, command substitution, and process substitution.
+ 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.
+ 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 pattern 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. 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 sta-
+ _\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; d\bdo\bo _\bl_\bi_\bs_\bt; d\bdo\bon\bne\be
- u\bun\bnt\bti\bil\bl _\bl_\bi_\bs_\bt; d\bdo\bo _\bl_\bi_\bs_\bt; d\bdo\bon\bne\be
- The w\bwh\bhi\bil\ble\be command continuously executes the d\bdo\bo _\bl_\bi_\bs_\bt as long as
- the last command in _\bl_\bi_\bs_\bt 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, except that the
- test is negated; the d\bdo\bo _\bl_\bi_\bs_\bt is executed as long as the last
- command in _\bl_\bi_\bs_\bt 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
- d\bdo\bo _\bl_\bi_\bs_\bt command executed, or zero if none was executed.
+ 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
+ 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,
+ except 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 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 exe-
+ cuted.
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
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. If _\bN_\bA_\bM_\bE is not supplied, the
- default name is _\bC_\bO_\bP_\bR_\bO_\bC. _\bN_\bA_\bM_\bE must not be supplied if _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a _\bs_\bi_\bm_\b-
+ default name is C\bCO\bOP\bPR\bRO\bOC\bC. _\bN_\bA_\bM_\bE must not be supplied if _\bc_\bo_\bm_\bm_\ba_\bn_\bd is a _\bs_\bi_\bm_\b-
_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd (see above); otherwise, it is interpreted as the first word
- of the simple command. When the coproc 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
+ of the simple command. When the coprocess is executed, the shell cre-
+ ates 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 descriptor 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 assigned 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. The process
- id of the shell spawned to execute the coprocess is available 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.
+ commands and redirections using standard word expansions. The file
+ descriptors are not available in subshells. The process ID of the
+ shell spawned to execute the coprocess is available 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.
- 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:
- [ f\bfu\bun\bnc\bct\bti\bio\bon\bn ] _\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 _\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. _\bc_\bo_\bm_\b-
+ _\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 _\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 _\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, with
+ one exception: If the f\bfu\bun\bnc\bct\bti\bio\bon\bn reserved word is used, but the
+ parentheses are not supplied, the braces are required. _\bc_\bo_\bm_\b-
_\bp_\bo_\bu_\bn_\bd_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd is executed whenever _\bn_\ba_\bm_\be is specified as the name
- of a simple command. Any redirections (see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below)
- specified when a function is defined are performed when the
- function is executed. The exit status of a function definition
- is zero unless a syntax error occurs or a readonly function with
- the same name already exists. When 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.)
+ of a simple command. When in _\bp_\bo_\bs_\bi_\bx _\bm_\bo_\bd_\be, _\bn_\ba_\bm_\be 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. Any redirections
+ (see R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN below) specified when a function is defined are
+ performed when the function is executed. The exit status of a
+ function definition is zero unless a syntax error occurs or a
+ readonly function with the same name already exists. When exe-
+ cuted, the exit status of a function is the exit status of the
+ 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-
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!. The characters $\b$ and `\b` retain
- their special meaning 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 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.
+ 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).
as follows:
\\b\a\ba alert (bell)
\\b\b\bb backspace
- \\b\e\be an escape character
+ \\b\e\be
+ \\b\E\bE an escape character
\\b\f\bf form feed
\\b\n\bn new line
\\b\r\br carriage return
\\b\v\bv vertical tab
\\b\\\b\ backslash
\\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
_\bn_\bn_\bn (one to three digits)
\\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
+ 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
+ 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
been present.
- A double-quoted string preceded by a dollar sign ($\b$) will cause the
- string to be translated according to the current locale. If the cur-
- rent locale is C\bC or P\bPO\bOS\bSI\bIX\bX, the dollar sign is ignored. If the string
- is translated and replaced, the replacement is double-quoted.
+ 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. If the
+ current locale is C\bC or P\bPO\bOS\bSI\bIX\bX, the dollar sign is ignored. If the
+ string is translated and replaced, the replacement is double-quoted.
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-
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
- 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).
+ 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 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-
+ 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 $((...)) expansion
- is not used (see A\bAr\bri\bit\bth\bhm\bme\bet\bti\bic\bc E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn below). Word splitting is not
- performed, with the exception of "\b"$\b$@\b@"\b" as explained below under S\bSp\bpe\bec\bci\bia\bal\bl
- P\bPa\bar\bra\bam\bme\bet\bte\ber\brs\bs. Pathname expansion is not performed. Assignment state-
- ments may also appear as arguments to the a\bal\bli\bia\bas\bs, d\bde\bec\bcl\bla\bar\bre\be, t\bty\byp\bpe\bes\bse\bet\bt,
- e\bex\bxp\bpo\bor\brt\bt, r\bre\bea\bad\bdo\bon\bnl\bly\by, and l\blo\boc\bca\bal\bl builtin commands.
+ is not used (see A\bAr\bri\bit\bth\bhm\bme\bet\bti\bic\bc E\bEx\bxp\bpa\ban\bns\bsi\bio\bon\bn below). Word splitting is not
+ performed, with the exception of "\b"$\b$@\b@"\b" as explained below under S\bSp\bpe\bec\bci\bia\bal\bl
+ P\bPa\bar\bra\bam\bme\bet\bte\ber\brs\bs. Pathname expansion is not performed. Assignment state-
+ ments 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\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. When += is applied to a vari-
- able for which the integer attribute has been set, _\bv_\ba_\bl_\bu_\be is evaluated
- as an arithmetic expression and added to the variable's current value,
- which is also evaluated. When += is applied to an array variable using
- compound assignment (see 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 applied to a string-valued variable, _\bv_\ba_\bl_\bu_\be is expanded and
- appended to the variable's value.
+ 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
+ _\bi_\bn_\bt_\be_\bg_\be_\br attribute has been set, _\bv_\ba_\bl_\bu_\be is evaluated as an arithmetic
+ expression and added to the variable's current value, which is also
+ evaluated. When += is applied to an array variable using compound
+ assignment (see 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
+ applied 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
+ attributes modified (other than 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 argument 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,
+ assignments, and attribute modifications to the variable whose name was
+ passed as $\b$1\b1. If the control variable in a f\bfo\bor\br loop has the nameref
+ attribute, the list of words can be a list of shell variables, and a
+ name reference will be established for each word in the list, in turn,
+ when the loop is executed. Array variables cannot be given the n\bna\bam\bme\ber\bre\bef\bf
+ attribute. However, nameref variables can reference array variables
+ and subscripted array variables. Namerefs can be unset using the -\b-n\bn
+ option to the u\bun\bns\bse\bet\bt builtin. Otherwise, if u\bun\bns\bse\bet\bt is executed with the
+ name of a nameref variable as an argument, the variable referenced by
+ the nameref variable will be unset.
P\bPo\bos\bsi\bit\bti\bio\bon\bna\bal\bl P\bPa\bar\bra\bam\bme\bet\bte\ber\brs\bs
A _\bp_\bo_\bs_\bi_\bt_\bi_\bo_\bn_\ba_\bl _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a parameter denoted by one or more digits,
The shell treats several parameters specially. These parameters may
only be referenced; assignment to them is not allowed.
*\b* Expands to the positional parameters, starting from one. When
- the expansion occurs within double quotes, it expands to a sin-
- gle word with the value of each parameter separated by the first
- character of the I\bIF\bFS\bS special variable. That is, "$\b$*\b*" is equiva-
- lent to "$\b$1\b1_\bc$\b$2\b2_\bc.\b..\b..\b.", where _\bc is the first character of the value
- of the I\bIF\bFS\bS variable. If I\bIF\bFS\bS is unset, the parameters are sepa-
- rated by spaces. If I\bIF\bFS\bS is null, the parameters are joined
- without intervening separators.
- @\b@ Expands to the positional parameters, starting from one. When
+ the expansion is not within double quotes, each positional
+ parameter expands to a separate word. In contexts where it is
+ performed, those words are subject to further word splitting and
+ pathname expansion. When the expansion occurs within double
+ quotes, it expands to a single word with the value of each
+ parameter separated by the first character of the I\bIF\bFS\bS special
+ variable. That is, "$\b$*\b*" is equivalent to "$\b$1\b1_\bc$\b$2\b2_\bc.\b..\b..\b.", where _\bc
+ is the first character of the value of the I\bIF\bFS\bS variable. If I\bIF\bFS\bS
+ is unset, the parameters are separated by spaces. If I\bIF\bFS\bS is
+ null, the parameters are joined without intervening separators.
+ @\b@ Expands to the positional parameters, starting from one. When
the expansion occurs within double quotes, each parameter
expands to a separate word. That is, "$\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$2\b2" ... If the double-quoted expansion occurs within a word,
+ the expansion of the first parameter is joined with the begin-
+ ning part of the original word, and the expansion of the last
+ parameter is joined with the last part of the original word.
+ When there are no positional parameters, "$\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
+ -\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
itself (such as the -\b-i\bi option).
- $\b$ Expands to the process ID of the shell. In a () subshell, it
- expands to the process ID of the current shell, not the sub-
+ $\b$ Expands to the process ID of the shell. In a () subshell, it
+ expands to the process ID of the current shell, not the sub-
shell.
- !\b! Expands to the process ID of the most recently executed back-
- ground (asynchronous) command.
+ !\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 file name used to invoke b\bba\bas\bsh\bh, as given by argument
+ set to the filename used to invoke b\bba\bas\bsh\bh, as given by argument
zero.
_\b_ At shell startup, set to the absolute pathname used to invoke
the shell or shell script being executed as passed in the envi-
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\bBA\bAS\bSH\bH Expands to the full file name used to invoke this instance of
+ 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.
B\bBA\bAS\bSH\bHP\bPI\bID\bD
- Expands to the process id of the current b\bba\bas\bsh\bh process. This
+ 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.
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 Ele-
- ments added to this array appear in the alias list; unsetting
- array elements cause aliases to be removed from the alias list.
+ 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
+ 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
+ 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
+ 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\bBA\bAS\bSH\bH_\b_A\bAR\bRG\bGV\bV
- An array variable containing all of the parameters in the cur-
+ 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
+ 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
+ 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
below)
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;
- unsetting array elements cause commands to be removed from 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-
+ 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
+ in which case it is the command executing at the time of the
trap.
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 corresponding to each member of F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE.
- $\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 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 refer-
- enced within another shell function). The corresponding source
- file name is $\b${\b{B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE[\b[_\b$_\bi]\b]}\b}. Use L\bLI\bIN\bNE\bEN\bNO\bO to obtain the cur-
- rent line number.
+ 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.
+ 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-
+ 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
string matching the _\bnth parenthesized subexpression. This vari-
able is read-only.
B\bBA\bAS\bSH\bH_\b_S\bSO\bOU\bUR\bRC\bCE\bE
- An array variable whose members are the source filenames corre-
- sponding to the elements in the F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE array variable.
+ 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
+ defined 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}.
B\bBA\bAS\bSH\bH_\b_S\bSU\bUB\bBS\bSH\bHE\bEL\bLL\bL
- Incremented by one each time a subshell or subshell environment
- is spawned. The initial value is 0.
+ Incremented by one within each subshell or subshell environment
+ when the shell begins executing in that environment. The ini-
+ tial value is 0.
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
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[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[3]\b] The build version.
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
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
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 pro-
- grammable 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).
-
+ 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 pro-
- grammable 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).
-
+ 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,
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 pro-
- grammable 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).
-
+ 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
+ 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
described above. This variable is available only in shell func-
- tions invoked by the programmable completion facilities (see
+ tions invoked by the programmable completion facilities (see
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
+ (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
+ 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
+ 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
- unset, it loses its special properties, even if it is subse-
+ able 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 subse-
quently reset.
-
- E\bEU\bUI\bID\bD Expands to the effective user ID of the current user, initial-
+ E\bEU\bUI\bID\bD Expands to the effective user ID of the current user, initial-
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
+ An array variable containing the names of all shell functions
currently in the execution call stack. The element with index 0
is the name of any currently-executing shell function. The bot-
- tom-most element 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 and return an error status. If F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE is unset, it
- loses its special properties, even if it is subsequently reset.
-
- 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
- and return an error status. If G\bGR\bRO\bOU\bUP\bPS\bS is unset, it loses its
- special properties, even if it is subsequently reset.
+ 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 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.
+ 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. If H\bHI\bIS\bST\bTC\bCM\bMD\bD is unset, it loses its special properties,
+ command. If H\bHI\bIS\bST\bTC\bCM\bMD\bD is unset, 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-
+ 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-
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
- script or function, the value substituted is not guaranteed to
+ 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
+ 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-
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-
+ 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.
-
+ 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\bOL\bLD\bDP\bPW\bWD\bD The previous working directory as set by the c\bcd\bd command.
-
O\bOP\bPT\bTA\bAR\bRG\bG The value of the last option argument 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\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-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
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 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, a random integer between
0 and 32767 is generated. The sequence of random numbers may be
initialized by assigning a value to R\bRA\bAN\bND\bDO\bOM\bM. If R\bRA\bAN\bND\bDO\bOM\bM is unset,
it loses its special properties, even if it is subsequently
reset.
-
+ R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE
+ The contents of the r\bre\bea\bad\bdl\bli\bin\bne\be line buffer, for use with "bind -x"
+ (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_\b_P\bPO\bOI\bIN\bNT\bT
+ The position of the insertion point in the r\bre\bea\bad\bdl\bli\bin\bne\be line buffer,
+ for use with "bind -x" (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\bEP\bPL\bLY\bY Set to the line of input read by the r\bre\bea\bad\bd builtin command when
no arguments are supplied.
-
S\bSE\bEC\bCO\bON\bND\bDS\bS
Each time this parameter is referenced, the number of seconds
since shell invocation is returned. If a value is assigned to
number of seconds since the assignment plus the value assigned.
If S\bSE\bEC\bCO\bON\bND\bDS\bS is unset, it loses its special properties, even if it
is subsequently reset.
-
S\bSH\bHE\bEL\bLL\bLO\bOP\bPT\bTS\bS
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
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.
-
S\bSH\bHL\bLV\bVL\bL Incremented by one each time an instance of b\bba\bas\bsh\bh is started.
-
U\bUI\bID\bD Expands to the user ID of the current user, initialized at shell
startup. This variable is readonly.
The following variables are used by the shell. In some cases, b\bba\bas\bsh\bh
assigns 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 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 a description of the various compatibility levels
+ and their effects. The value may be a decimal number (e.g.,
+ 4.2) or an integer (e.g., 42) corresponding to the desired com-
+ patibility 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 compatibility levels correspond to
+ the compatibility options accepted by the s\bsh\bho\bop\bpt\bt builtin
+ described below (for example, c\bco\bom\bmp\bpa\bat\bt4\b42\b2 means that 4.2 and 42 are
+ valid values). 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
+ 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
- subjected to parameter expansion, command substitution, and
- arithmetic expansion before being interpreted as a file name.
- P\bPA\bAT\bTH\bH is not used to search for the resultant file name.
+ 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
+ enabled 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
+ 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
list of directories in which the shell looks for destination
directories 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. Bash 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 builtin command to determine the terminal
- width when printing selection lists. Automatically set upon
- receipt of a SIGWINCH.
+ 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
+ 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).
+ 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.
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.
+ an Emacs shell buffer and disables line editing.
+ E\bEN\bNV\bV Similar to B\bBA\bAS\bSH\bH_\b_E\bEN\bNV\bV; used when the shell is invoked in POSIX
+ mode.
+ 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.
+ Files whose full pathnames match one of these patterns are not
+ considered executable files for the purposes of completion and
+ command execution. This does not affect the behavior of the [\b[,
+ t\bte\bes\bst\bt, and [\b[[\b[ commands. Use this variable to ignore shared
+ library files that have the executable bit set, but are not exe-
+ cutable 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
+ 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-
- fix matches one of the entries in F\bFI\bIG\bGN\bNO\bOR\bRE\bE is excluded from the
+ 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:~".
+ 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
+ nesting level will cause the current command to abort.
G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE
A colon-separated list of patterns defining the set of filenames
to be ignored by pathname expansion. If a filename matched by a
- pathname expansion pattern also matches one of the patterns in
+ 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.
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_\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
+ A colon-separated list of values controlling how commands are
+ saved on the history list. If the list of values includes
+ _\bi_\bg_\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
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
- unset, or does not include a valid value, all lines read by the
+ 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
+ unset, or does not include a valid value, all lines read by the
shell parser are saved on the history list, subject to the value
- of H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE. The second and subsequent lines of a multi-line
- compound command are not tested, and are added to the history
+ of H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE. The second and subsequent lines of a multi-line
+ compound command are not tested, and are added to the history
regardless of the value of 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). The default value is _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bh_\bi_\bs_\bt_\bo_\br_\by. If unset,
- the command history is not saved when an interactive shell
- exits.
+ T\bTO\bOR\bRY\bY below). The default value is _\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bh_\bi_\bs_\bt_\bo_\br_\by. If unset,
+ 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, by removing the oldest entries, to contain
- no more than that number of lines. The default value is 500.
- The history file is also truncated to this size after writing it
- when an interactive shell exits.
+ cated, if necessary, to contain no more than that number of
+ lines by removing the oldest entries. The history file is also
+ truncated to this size after writing it when 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
- anchored at the beginning of the line and must match the com-
- plete 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\bN-\b-
- T\bTR\bRO\bOL\bL are applied. In addition to the normal shell pattern
+ A colon-separated list of patterns used to decide which command
+ lines should be saved on the history list. Each pattern is
+ anchored at the beginning of the line and must match the com-
+ plete line (no implicit `*\b*' is appended). Each pattern is
+ tested against the line after the checks specified by H\bHI\bIS\bST\bTC\bCO\bON\bN-\b-
+ T\bTR\bRO\bOL\bL are applied. In addition to the normal shell pattern
matching characters, `&\b&' matches the previous history line. `&\b&'
- may be escaped using a backslash; the backslash is removed
+ may be escaped using a backslash; the backslash is removed
before attempting a match. The second and subsequent lines of a
multi-line compound command are not tested, and are added to the
- history regardless of the value of H\bHI\bIS\bST\bTI\bIG\bGN\bNO\bOR\bRE\bE.
+ history 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.
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). The default value is 500.
+ 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
the shell is running; the next time hostname completion is
attempted 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
- no value, 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 completions. When H\bHO\bOS\bST\bTF\bFI\bIL\bLE\bE is unset, the
- hostname list is cleared.
+ 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.
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
after expansion and to split lines into words with the r\bre\bea\bad\bd
builtin command. The default value is ``<space><tab><new-
L\bLC\bC_\b_N\bNU\bUM\bME\bER\bRI\bIC\bC
This variable determines the locale category used for number
formatting.
- L\bLI\bIN\bNE\bES\bS Used by the s\bse\bel\ble\bec\bct\bt builtin command to determine the column
- length for printing selection lists. Automatically set upon
- receipt of a SIGWINCH.
- M\bMA\bAI\bIL\bL If this parameter is set to a file name and the M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH vari-
- able is not set, b\bba\bas\bsh\bh informs the user of the arrival of mail in
- the specified file.
+ L\bLC\bC_\b_T\bTI\bIM\bME\bE
+ 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
+ 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
+ arrival of mail in the specified file or Maildir-format direc-
+ tory.
M\bMA\bAI\bIL\bLC\bCH\bHE\bEC\bCK\bK
- Specifies how often (in seconds) b\bba\bas\bsh\bh checks for mail. The
- default is 60 seconds. When it is time to check for mail, the
- shell does so before displaying the primary prompt. If this
- variable is unset, or set to a value that is not a number
+ Specifies how often (in seconds) b\bba\bas\bsh\bh checks for mail. The
+ default is 60 seconds. When it is time to check for mail, the
+ shell does so before displaying the primary prompt. If this
+ variable is unset, or set to a value that is not a number
greater than or equal to zero, the shell disables mail checking.
M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH
- A colon-separated list of file names to be checked for mail.
- The message to be printed when mail arrives in a particular file
- may be specified by separating the file name from the message
- with a `?'. When used in the text of the message, $\b$_\b_ expands to
- the name of the current mailfile. Example:
+ 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:
M\bMA\bAI\bIL\bLP\bPA\bAT\bTH\bH='/var/mail/bfox?"You have mail":~/shell-mail?"$_ has
mail!"'
B\bBa\bas\bsh\bh supplies a default value for this variable, but the loca-
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/gnu/bin:/usr/local/bin:/usr/ucb:/bin:/usr/bin''.
+ ``/usr/local/bin:/usr/local/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
+ 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.
P\bPR\bRO\bOM\bMP\bPT\bT_\b_C\bCO\bOM\bMM\bMA\bAN\bND\bD
If set, the value is executed as a command prior to issuing each
primary prompt.
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 a\ban\bnd\bd \\b\W\bW p\bpr\bro\bom\bmp\bpt\bt s\bst\btr\bri\bin\bng\bg e\bes\bsc\bca\bap\bpe\bes\bs (\b(s\bse\bee\be P\bPR\bRO\bOM\bMP\bPT\bTI\bIN\bNG\bG below).
+ 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\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\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
``\\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
+ 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
- value is printed before each command b\bba\bas\bsh\bh displays during an
- execution trace. The first character of P\bPS\bS4\b4 is replicated mul-
- tiple times, as necessary, to indicate multiple levels of indi-
+ 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
+ execution trace. The first character of P\bPS\bS4\b4 is replicated mul-
+ tiple times, as necessary, to indicate multiple levels of indi-
rection. The default is ``+\b+ ''.
S\bSH\bHE\bEL\bLL\bL The full pathname to the shell is kept in this environment vari-
- able. If it is not set when the shell starts, b\bba\bas\bsh\bh assigns to
+ able. 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
+ 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 three places
- after the decimal point may be specified; values of _\bp greater
- than 3 are changed to 3. If _\bp is not specified, the value 3 is
+ after the decimal point may be specified; values of _\bp greater
+ than 3 are changed to 3. 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 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%3\b3l\blS\bS'\b'. If the value is null, no
- timing information is displayed. A trailing newline is added
+ 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,
+ no timing information is displayed. A trailing newline 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
+ T\bTM\bMO\bOU\bUT\bT If set to a value greater than zero, T\bTM\bMO\bOU\bUT\bT is treated as the
default 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
- interpreted as the number of seconds to wait for input after
- issuing the primary prompt. B\bBa\bas\bsh\bh terminates after waiting for
- that number of seconds if 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
- B\bBa\bas\bsh\bh creates temporary files for the shell's use.
-
+ 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
+ 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
+ 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-
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
explicitly declare an array. There is no maximum limit on the size of
an array, nor any requirement that members be indexed or assigned con-
tiguously. Indexed arrays are referenced using integers (including
- arithmetic expressions) and are zero-based; associative arrays are
- referenced using arbitrary strings.
+ arithmetic expressions) and are zero-based; associative arrays are ref-
+ 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
+ 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 greater than or
- equal to zero. 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\bMM\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_\bs_\bc_\br_\bi_\bp_\bt is ignored.
+ 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 is 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 the bracket
- and subscript. When assigning to indexed arrays, if the optional
- brackets and subscript are supplied, that index is assigned to; other-
- wise the index of the element assigned is the last index assigned to by
- the statement plus one. Indexing starts at zero.
+ _\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. When assigning to indexed arrays, if the optional brackets and
+ subscript are supplied, that index is assigned to; otherwise the index
+ of the element assigned is the last index assigned to by the statement
+ plus one. Indexing starts at zero.
When assigning to an associative array, the subscript is required.
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
- introduced above.
+ introduced 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.
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
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_\b-
_\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 ele-
- ments in the array. Referencing an array variable without a subscript
- is equivalent to referencing the array with a subscript of 0.
+ ments in the array. 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 inter-
+ preted 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
+ using a valid subscript is legal, 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.
+
+ 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]
- destroys the array element at index _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt. Care must be taken to
- avoid unwanted side effects caused by filename generation. u\bun\bns\bse\bet\bt _\bn_\ba_\bm_\be,
- where _\bn_\ba_\bm_\be is an array, or 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@, removes the entire 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
- array. 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 assign-
- ments.
+ destroys the array element at index _\bs_\bu_\bb_\bs_\bc_\br_\bi_\bp_\bt. Negative subscripts to
+ indexed arrays are interpreted as described above. Care must be taken
+ to avoid unwanted side effects caused by pathname expansion. u\bun\bns\bse\bet\bt
+ _\bn_\ba_\bm_\be, where _\bn_\ba_\bm_\be is an array, or 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@, removes the entire 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
+ array. 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, parame-
- ter, variable and arithmetic expansion and command substitution (done
- in a left-to-right fashion), word splitting, and pathname expansion.
+ 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-
+ 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.
+ 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.
Only brace expansion, word splitting, and pathname expansion can change
the number of words of the expansion; other expansions expand a single
or _\by begins with a zero, the shell attempts to force all generated
terms to contain the same number of digits, zero-padding where neces-
sary. When characters are supplied, the expression expands to each
- character lexicographically between _\bx and _\by, inclusive. Note that both
- _\bx and _\by must be of the same type. When the increment is supplied, it
- is used as the difference between each term. The default increment is
- 1 or -1 as appropriate.
+ character lexicographically between _\bx and _\by, inclusive, using the
+ default C locale. Note that both _\bx and _\by must be of the same type.
+ When the increment is supplied, it is used as the difference between
+ each term. The default increment is 1 or -1 as appropriate.
Brace expansion is performed before any other expansions, and any char-
acters special to other expansions are preserved in the result. It is
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 file names with tildes in
+ also performed. Consequently, one may use filenames with tildes in
assignments 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
expanded value.
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.
-
- If the first character of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an exclamation point, a level of
- variable indirection is introduced. B\bBa\bas\bsh\bh uses the value of the vari-
- able formed from the rest of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br as the name of the variable;
- this variable is then expanded and that value is used in the rest of
- the substitution, rather than the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br itself. This is
- known as _\bi_\bn_\bd_\bi_\br_\be_\bc_\bt _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn. The exceptions to this are the expansions
- of ${!_\bp_\br_\be_\bf_\bi_\bx*} and ${!\b!_\bn_\ba_\bm_\be[_\b@]} described below. The exclamation point
- must immediately follow the left brace in order to introduce indirec-
- tion.
+ 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 variable indirec-
+ tion. B\bBa\bas\bsh\bh uses the value of the variable formed from the rest of
+ _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br as the name of the variable; this variable is then expanded
+ and that value is used in the rest of the substitution, rather than the
+ value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br itself. This is known as _\bi_\bn_\bd_\bi_\br_\be_\bc_\bt _\be_\bx_\bp_\ba_\bn_\bs_\bi_\bo_\bn. If
+ _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is a nameref, this expands to the name of the variable refer-
+ enced by _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br instead of performing the complete indirect expan-
+ sion. 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 indirection.
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
- below, 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 unset.
+ below (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
+ unset.
${_\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 expan-
- sion of _\bw_\bo_\br_\bd is substituted. Otherwise, the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br
+ 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
+ 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
expansion 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_\b-
- _\be_\bt_\be_\br is then substituted. Positional parameters and special
+ _\be_\bt_\be_\br is then substituted. Positional parameters and special
parameters 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
+ 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.\b. Expands to up to _\bl_\be_\bn_\bg_\bt_\bh characters of
- _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br starting at the character specified by _\bo_\bf_\bf_\bs_\be_\bt. If
- _\bl_\be_\bn_\bg_\bt_\bh is omitted, expands to the substring of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br start-
- ing at the character specified by _\bo_\bf_\bf_\bs_\be_\bt. _\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).
- _\bl_\be_\bn_\bg_\bt_\bh must evaluate to a number greater than or equal to zero.
+ 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@, an indexed array subscripted by @\b@ or *\b*,
+ or an associative array name, the results differ as described
+ 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
- used as an offset from the end of the value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. If
- _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@, the result is _\bl_\be_\bn_\bg_\bt_\bh positional parameters
- beginning at _\bo_\bf_\bf_\bs_\be_\bt. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is an indexed array name sub-
- scripted by @ or *, the result is the _\bl_\be_\bn_\bg_\bt_\bh members of the
- array beginning with ${_\bp_\ba_\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. Substring expansion applied to an associative
- array produces undefined results. Note that a negative offset
- must be separated from the colon by at least one space to avoid
- being confused with the :- expansion. Substring indexing is
- zero-based unless the positional parameters are used, in which
- case the indexing starts at 1 by default. If _\bo_\bf_\bf_\bs_\be_\bt is 0, and
- the positional parameters are used, $\b$0\b0 is prefixed to the list.
+ used as an offset in characters from the end of the value of
+ _\bp_\ba_\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
+ expansion 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- expan-
+ sion.
+
+ If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@, the result is _\bl_\be_\bn_\bg_\bt_\bh positional parameters
+ 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. It is an expan-
+ sion 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_\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
+ undefined results.
+
+ Substring indexing is zero-based unless the positional parame-
+ ters are used, in which case the indexing starts at 1 by
+ default. 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.\b. 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.\b. 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,
+ 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.\b. The length in characters of the value of
- _\bp_\ba_\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
- substituted is the number of positional parameters. If _\bp_\ba_\br_\ba_\bm_\be_\b-
- _\bt_\be_\br is an array name subscripted by *\b* or @\b@, the value substi-
- tuted is the number of elements in the array.
+ 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_\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
+ substituted is the number of positional parameters. If _\bp_\ba_\br_\ba_\bm_\be_\b-
+ _\bt_\be_\br is an array name subscripted by *\b* or @\b@, the value substi-
+ tuted 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 interpreted as relative to one greater than the maxi-
+ mum 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 ele-
+ ment.
${_\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.\b. 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. 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
${_\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.\b. 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. 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 expansion is the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br with
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}
- P\bPa\bat\btt\bte\ber\brn\bn s\bsu\bub\bbs\bst\bti\bit\btu\but\bti\bio\bon\bn.\b. The _\bp_\ba_\bt_\bt_\be_\br_\bn is expanded to produce a pat-
+ 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. If _\bp_\ba_\bt_\bt_\be_\br_\bn begins with /\b/, all matches of _\bp_\ba_\bt_\bt_\be_\br_\bn are
ning of the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br. If _\bp_\ba_\bt_\bt_\be_\br_\bn begins with
%\b%, it must match at the end of the expanded value of _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br.
If _\bs_\bt_\br_\bi_\bn_\bg is null, matches of _\bp_\ba_\bt_\bt_\be_\br_\bn are deleted and the /\b/ fol-
- lowing _\bp_\ba_\bt_\bt_\be_\br_\bn may be omitted. If _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br is @\b@ or *\b*, the sub-
- stitution 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 substitution
- operation is applied to each member of the array in turn, and
- the expansion is the resultant list.
+ lowing _\bp_\ba_\bt_\bt_\be_\br_\bn may be omitted. 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 _\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 resultant 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.
${_\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.\b. This expansion modifies the case of alpha-
+ 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. The ^\b^ operator
- 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
- list.
+ 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^
+ operator converts lowercase letters matching _\bp_\ba_\bt_\bt_\be_\br_\bn to upper-
+ case; the ,\b, operator converts matching uppercase letters to low-
+ ercase. 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
+ omitted, 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 sub-
+ scripted 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
+ single letter:
+
+ 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
+ $\b$'\b'.\b..\b..\b.'\b' quoting mechansim.
+ 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
+ recreate _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br with its attributes and value.
+ a\ba The expansion is a string consisting of flag values rep-
+ resenting _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br's attributes.
+
+ 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 case modification 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
+ 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 name. There are two forms:
-
$\b$(\b(_\bc_\bo_\bm_\bm_\ba_\bn_\bd)\b)
or
`\b`_\bc_\bo_\bm_\bm_\ba_\bn_\bd`\b`
- B\bBa\bas\bsh\bh performs the expansion by executing _\bc_\bo_\bm_\bm_\ba_\bn_\bd and replacing the com-
- mand 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).
+ 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 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).
When the old-style backquote form of substitution is used, backslash
retains its literal meaning except when followed by $\b$, `\b`, or \\b\. The
The _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn is treated as if it were within double quotes, but a
double quote inside the parentheses is not treated specially. All
- tokens in the expression undergo parameter expansion, string expansion,
- command substitution, and quote removal. Arithmetic expansions may be
+ tokens in the expression undergo parameter and variable expansion, com-
+ mand 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
+ 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 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. 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 with its input or out-
- put connected to a _\bF_\bI_\bF_\bO or some file in /\b/d\bde\bev\bv/\b/f\bfd\bd. The name of this file
- is passed as an argument to the current command as the result of the
- expansion. If the >\b>(\b(_\bl_\bi_\bs_\bt)\b) form is used, writing to the file will pro-
- vide 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.
+ _\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
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 on these characters. 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 default,
- then sequences of <\b<s\bsp\bpa\bac\bce\be>\b>, <\b<t\bta\bab\bb>\b>, and <\b<n\bne\bew\bwl\bli\bin\bne\be>\b> at the beginning and
- end of the results of the previous expansions are ignored, and any
- sequence 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 and t\bta\bab\bb 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.
-
- Explicit null arguments ("\b""\b" or '\b''\b') are retained. Unquoted implicit
- null arguments, resulting from the expansion of parameters that have no
- values, are removed. If a parameter with no value is expanded within
- double quotes, a null argument results and is retained.
+ 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 default, then sequences of <\b<s\bsp\bpa\bac\bce\be>\b>, <\b<t\bta\bab\bb>\b>,
+ and <\b<n\bne\bew\bwl\bli\bin\bne\be>\b> at the beginning and end of the results of the previous
+ expansions are ignored, and any sequence 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 white-
+ space 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.
+
+ 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
+ results 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.
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, then the word is regarded as a _\bp_\ba_\bt_\bt_\be_\br_\bn, and replaced with an
- alphabetically sorted list of file names matching the pattern. If no
- matching file names 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 without regard to the case of alpha-
- betic 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. When matching a pathname, the slash character must always be
- matched explicitly. In other cases, the `\b``\b`.\b.'\b''\b' character is not
- treated specially. 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, f\bfa\bai\bil\bl-\b-
- g\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. The file names `\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\bG-\b-
- N\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 file names beginning with a `\b``\b`.\b.'\b''\b' will match. To
- get the old behavior of ignoring file names 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.
+ alphabetically sorted list of filenames matching the pattern (see P\bPa\bat\bt-\b-
+ t\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 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 explicitly, unless the
+ shell option d\bdo\bot\btg\bgl\blo\bob\bb is set. When matching a pathname, the slash char-
+ acter must always be matched explicitly. In other cases, the `\b``\b`.\b.'\b''\b'
+ character is not treated specially. 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\bl-\b-
+ g\bgl\blo\bob\bb, 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 filename
+ 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
+ beginning with a `\b``\b`.\b.'\b''\b' will match. To get the old behavior of ignor-
+ ing 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.
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\bb-\b-
- s\bst\bta\bar\br shell option is enabled, and *\b* is used in a filename expan-
- sion context, two adjacent *\b*s used as a single pattern will
- match all files and zero or more directories and subdirectories.
- If followed by a /\b/, two adjacent *\b*s will match only directories
- and subdirectories.
- ?\b? Matches any single character.
- [\b[.\b..\b..\b.]\b] Matches any one of the enclosed characters. A pair of charac-
- ters separated by a hyphen denotes a _\br_\ba_\bn_\bg_\be _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn; any char-
- acter that sorts between those two characters, inclusive, using
- the current locale's collating sequence and character set, is
- matched. If the first character following the [\b[ is a !\b! or a ^\b^
- then any character not enclosed is matched. The sorting order
- of characters in range expressions is determined by the current
- locale and the value of the L\bLC\bC_\b_C\bCO\bOL\bLL\bLA\bAT\bTE\bE shell variable, if set.
- A -\b- may be matched by including it as the first or last charac-
- ter in the set. A ]\b] may be matched by including it as the first
- character in the set.
-
- Within [\b[ and ]\b], _\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br _\bc_\bl_\ba_\bs_\bs_\be_\bs can be specified using the
- syntax [\b[:\b:_\bc_\bl_\ba_\bs_\bs:\b:]\b], where _\bc_\bl_\ba_\bs_\bs is one of the following classes
- defined in the POSIX standard:
- 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, and the char-
- acter _.
-
- Within [\b[ and ]\b], an _\be_\bq_\bu_\bi_\bv_\ba_\bl_\be_\bn_\bc_\be _\bc_\bl_\ba_\bs_\bs can be specified using the
- syntax [\b[=\b=_\bc=\b=]\b], which matches all characters with the same colla-
- tion weight (as defined by the current locale) as the character
- _\bc.
-
- Within [\b[ and ]\b], the syntax [\b[.\b._\bs_\by_\bm_\bb_\bo_\bl.\b.]\b] matches the collating sym-
- bol _\bs_\by_\bm_\bb_\bo_\bl.
+ *\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
+ directories 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
+ 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
+ sequence and character set, is matched. If the first
+ character following the [\b[ is a !\b! or a ^\b^ then any charac-
+ ter not enclosed is matched. The sorting order of char-
+ acters in range expressions is determined by the current
+ locale and the values 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 interpreta-
+ tion of range expressions, 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\bii\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.
+
+ Within [\b[ and ]\b], _\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br _\bc_\bl_\ba_\bs_\bs_\be_\bs can be specified using
+ the syntax [\b[:\b:_\bc_\bl_\ba_\bs_\bs:\b:]\b], where _\bc_\bl_\ba_\bs_\bs is one of the following
+ classes defined in the POSIX standard:
+ 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,
+ 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
+ using the syntax [\b[=\b=_\bc=\b=]\b], which matches all characters with
+ the same collation weight (as defined by the current
+ locale) as the character _\bc.
+
+ Within [\b[ and ]\b], the syntax [\b[.\b._\bs_\by_\bm_\bb_\bo_\bl.\b.]\b] matches the collat-
+ 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, several
- extended pattern matching operators are recognized. In the following
+ extended pattern matching operators are recognized. 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 fol-
lowing sub-patterns:
Q\bQu\buo\bot\bte\be R\bRe\bem\bmo\bov\bva\bal\bl
After the preceding expansions, all unquoted occurrences of the charac-
- ters \\b\, '\b', and "\b" that did not result from one of the above expansions
+ ters \\b\, '\b', and "\b" that did not result from one of the above expansions
are removed.
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. Redirection may
- also be used to open and close files for the current shell execution
- environment. The following redirection operators may precede or appear
- anywhere within a _\bs_\bi_\bm_\bp_\bl_\be _\bc_\bo_\bm_\bm_\ba_\bn_\bd or may follow a _\bc_\bo_\bm_\bm_\ba_\bn_\bd. Redirections
- are processed in the order they appear, from left to right.
-
- 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
- first character of the redirection operator is >\b>, the redirection
+ 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. Redirection 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-
+ 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,
+ 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
+ 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.
+
+ 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
+ first character of the redirection operator is >\b>, the redirection
refers to the standard output (file descriptor 1).
- The word following the redirection operator in the following descrip-
- tions, unless otherwise noted, is subjected to brace expansion, tilde
- expansion, parameter expansion, command substitution, arithmetic expan-
- sion, quote removal, pathname expansion, and word splitting. If it
- expands to more than one word, b\bba\bas\bsh\bh reports an error.
+ The word following the redirection operator in the following descrip-
+ 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.
- Note that the order of redirections is significant. For example, the
+ Note that the order of redirections is significant. For example, the
command
ls >\b> dirlist 2>\b>&\b&1
- directs both standard output and standard error to the file _\bd_\bi_\br_\bl_\bi_\bs_\bt,
+ directs both standard output and standard error to the file _\bd_\bi_\br_\bl_\bi_\bs_\bt,
while the command
ls 2>\b>&\b&1 >\b> dirlist
- directs only the standard output to file _\bd_\bi_\br_\bl_\bi_\bs_\bt, because the standard
- error was duplicated from the standard output before the standard out-
+ directs only the standard output to file _\bd_\bi_\br_\bl_\bi_\bs_\bt, because the standard
+ error was duplicated from the standard output before the standard out-
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:
/\b/d\bde\bev\bv/\b/f\bfd\bd/\b/_\bf_\bd
- If _\bf_\bd is a valid integer, file descriptor _\bf_\bd is dupli-
+ If _\bf_\bd is a valid integer, file descriptor _\bf_\bd is dupli-
cated.
/\b/d\bde\bev\bv/\b/s\bst\btd\bdi\bin\bn
File descriptor 0 is duplicated.
File descriptor 2 is duplicated.
/\b/d\bde\bev\bv/\b/t\btc\bcp\bp/\b/_\bh_\bo_\bs_\bt/\b/_\bp_\bo_\br_\bt
If _\bh_\bo_\bs_\bt is a valid hostname or Internet address, and _\bp_\bo_\br_\bt
- is an integer port number or service name, b\bba\bas\bsh\bh attempts
- to open a TCP connection to the corresponding socket.
+ is an integer port number or service name, b\bba\bas\bsh\bh attempts
+ to open the corresponding TCP socket.
/\b/d\bde\bev\bv/\b/u\bud\bdp\bp/\b/_\bh_\bo_\bs_\bt/\b/_\bp_\bo_\br_\bt
If _\bh_\bo_\bs_\bt is a valid hostname or Internet address, and _\bp_\bo_\br_\bt
- is an integer port number or service name, b\bba\bas\bsh\bh attempts
- to open a UDP connection to the corresponding socket.
+ is an integer port number or service name, b\bba\bas\bsh\bh attempts
+ to open the corresponding UDP socket.
A failure to open or create a file causes the redirection to fail.
- Redirections using file descriptors greater than 9 should be used with
- care, as they may conflict with file descriptors the shell uses inter-
+ Redirections using file descriptors greater than 9 should be used with
+ care, as they may conflict with file descriptors the shell uses inter-
nally.
R\bRe\bed\bdi\bir\bre\bec\bct\bti\bin\bng\bg I\bIn\bnp\bpu\but\bt
Redirection of input causes the file whose name results from the expan-
- sion of _\bw_\bo_\br_\bd to be opened for reading on file descriptor _\bn, or the
+ sion of _\bw_\bo_\br_\bd to be opened for reading on file descriptor _\bn, or the
standard input (file descriptor 0) if _\bn is not specified.
The general format for redirecting input is:
[_\bn]<\b<_\bw_\bo_\br_\bd
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
+ Redirection of output causes the file whose name results from the
expansion 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
- does not exist it is created; if it does exist it is truncated to zero
+ does not exist it is created; if it does exist it is truncated to zero
size.
The general format for redirecting output is:
[_\bn]>\b>_\bw_\bo_\br_\bd
- If the redirection operator is >\b>, and the n\bno\boc\bcl\blo\bob\bbb\bbe\ber\br option to the s\bse\bet\bt
- builtin has been enabled, the redirection will fail if the file whose
- name results from the expansion of _\bw_\bo_\br_\bd exists and is a regular file.
+ If the redirection operator is >\b>, and the n\bno\boc\bcl\blo\bob\bbb\bbe\ber\br option to the s\bse\bet\bt
+ builtin has been enabled, the redirection will fail if the file whose
+ name results from the expansion of _\bw_\bo_\br_\bd exists and is a regular file.
If the redirection operator is >\b>|\b|, or the redirection operator is >\b> and
the n\bno\boc\bcl\blo\bob\bbb\bbe\ber\br option to the s\bse\bet\bt builtin command is not enabled, the re-
direction is attempted even if the file named by _\bw_\bo_\br_\bd exists.
A\bAp\bpp\bpe\ben\bnd\bdi\bin\bng\bg R\bRe\bed\bdi\bir\bre\bec\bct\bte\bed\bd O\bOu\but\btp\bpu\but\bt
- Redirection of output in this fashion causes the file whose name
- results from the expansion of _\bw_\bo_\br_\bd to be opened for appending on file
- descriptor _\bn, or the standard output (file descriptor 1) if _\bn is not
+ Redirection of output in this fashion causes the file whose name
+ results from the expansion of _\bw_\bo_\br_\bd to be opened for appending on file
+ descriptor _\bn, or the standard output (file descriptor 1) if _\bn is not
specified. If the file does not exist it is created.
The general format for appending output is:
[_\bn]>\b>>\b>_\bw_\bo_\br_\bd
-
R\bRe\bed\bdi\bir\bre\bec\bct\bti\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
- the standard error output (file descriptor 2) to be redirected to the
+ This construct allows both the standard output (file descriptor 1) and
+ the standard error output (file descriptor 2) to be redirected to the
file whose name is the expansion of _\bw_\bo_\br_\bd.
- There are two formats for redirecting standard output and standard
+ There are two formats for redirecting standard output and standard
error:
&\b&>\b>_\bw_\bo_\br_\bd
>\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\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
- the standard error output (file descriptor 2) to be appended to the
+ This construct allows both the standard output (file descriptor 1) and
+ the standard error output (file descriptor 2) to be appended to the
file whose name is the expansion of _\bw_\bo_\br_\bd.
The format for appending standard output and standard error is:
>\b>>\b>_\bw_\bo_\br_\bd 2>\b>&\b&1
+ (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\bpt\bto\bor\brs\bs below).
+
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
+ 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
- as the standard input for a command.
+ blanks) is seen. 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.
The format of here-documents is:
- <\b<<\b<[-\b-]_\bw_\bo_\br_\bd
+ [_\bn]<\b<<\b<[-\b-]_\bw_\bo_\br_\bd
_\bh_\be_\br_\be_\b-_\bd_\bo_\bc_\bu_\bm_\be_\bn_\bt
_\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br
- No parameter expansion, command substitution, arithmetic expansion, or
- pathname expansion is performed on _\bw_\bo_\br_\bd. If any characters in _\bw_\bo_\br_\bd are
- quoted, the _\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br is the result of quote removal on _\bw_\bo_\br_\bd, and the
- lines in the here-document are not expanded. If _\bw_\bo_\br_\bd is unquoted, all
- lines of the here-document are subjected to parameter expansion, com-
- mand substitution, and arithmetic expansion. In the latter case, the
- character sequence \\b\<\b<n\bne\bew\bwl\bli\bin\bne\be>\b> is ignored, and \\b\ must be used to quote
- the characters \\b\, $\b$, and `\b`.
+ No parameter and variable expansion, command substitution, arithmetic
+ expansion, or pathname expansion is performed on _\bw_\bo_\br_\bd. If any charac-
+ ters in _\bw_\bo_\br_\bd are quoted, the _\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br is the result of quote removal
+ on _\bw_\bo_\br_\bd, and the lines in the here-document are not expanded. If _\bw_\bo_\br_\bd
+ is unquoted, all lines of the here-document are subjected to parameter
+ expansion, command substitution, and arithmetic expansion, the charac-
+ ter sequence \\b\<\b<n\bne\bew\bwl\bli\bin\bne\be>\b> is ignored, and \\b\ must be used to quote the
+ characters \\b\, $\b$, and `\b`.
If the redirection operator is <\b<<\b<-\b-, then all leading tab characters are
stripped from input lines and the line containing _\bd_\be_\bl_\bi_\bm_\bi_\bt_\be_\br. This
H\bHe\ber\bre\be S\bSt\btr\bri\bin\bng\bgs\bs
A variant of here documents, the format is:
- <\b<<\b<<\b<_\bw_\bo_\br_\bd
+ [_\bn]<\b<<\b<<\b<_\bw_\bo_\br_\bd
- The _\bw_\bo_\br_\bd is expanded and supplied to the command on its standard input.
+ The _\bw_\bo_\br_\bd undergoes brace expansion, tilde expansion, parameter and
+ variable expansion, command substitution, arithmetic expansion, and
+ quote removal. Pathname expansion and word splitting are not per-
+ formed. 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
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. As a special case, if _\bn is omitted, and _\bw_\bo_\br_\bd
- does not expand to one or more digits, the standard output and standard
- error are redirected as described previously.
+ 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
The redirection operator
[_\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
+ 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
being duplicated to _\bn.
[_\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
+ moves the file descriptor _\bd_\bi_\bg_\bi_\bt to file descriptor _\bn, or the standard
output (file descriptor 1) if _\bn is not specified.
O\bOp\bpe\ben\bni\bin\bng\bg F\bFi\bil\ble\be D\bDe\bes\bsc\bcr\bri\bip\bpt\bto\bor\brs\bs f\bfo\bor\br R\bRe\bea\bad\bdi\bin\bng\bg a\ban\bnd\bd W\bWr\bri\bit\bti\bin\bng\bg
[_\bn]<\b<>\b>_\bw_\bo_\br_\bd
- 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
+ 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.
A\bAL\bLI\bIA\bAS\bSE\bES\bS
- _\bA_\bl_\bi_\ba_\bs_\be_\bs allow a string to be substituted for a word when it is used as
- the first word of a simple command. The shell maintains a list of
- aliases that may be set and unset with the a\bal\bli\bia\bas\bs and u\bun\bna\bal\bli\bia\bas\bs builtin
- commands (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 first word of each
- simple command, if unquoted, is checked to see if it has an alias. If
- so, that word is replaced by the text of the alias. The characters /\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
+ _\bA_\bl_\bi_\ba_\bs_\be_\bs allow a string to be substituted for a word when it is used as
+ the first word of a simple command. The shell maintains a list of
+ aliases that may be set and unset with the a\bal\bli\bia\bas\bs and u\bun\bna\bal\bli\bia\bas\bs builtin
+ commands (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 first word of each
+ simple command, if unquoted, is checked to see if it has an alias. If
+ so, that word is replaced by the text of the alias. The characters /\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 replacement text may
- contain any valid shell input, including shell metacharacters. The
- first word of the replacement text is tested for aliases, but a word
- that is identical to an alias being expanded is not expanded a second
- time. This means that one may alias 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. If the
- last character of the alias value is a _\bb_\bl_\ba_\bn_\bk, then the next command
+ contain any valid shell input, including shell metacharacters. The
+ first word of the replacement text is tested for aliases, but a word
+ that is identical to an alias being expanded is not expanded a second
+ time. This means that one may alias 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. If the
+ last character of the alias value is a _\bb_\bl_\ba_\bn_\bk, then the next command
word following the alias is also checked for alias expansion.
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
- arguments are needed, a shell function should be used (see F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS
+ There is no mechanism for using arguments in the replacement text. If
+ arguments are needed, a shell function should be used (see F\bFU\bUN\bNC\bCT\bTI\bIO\bON\bNS\bS
below).
- Aliases are not expanded when the shell is not interactive, unless the
- e\bex\bxp\bpa\ban\bnd\bd_\b_a\bal\bli\bia\bas\bse\bes\bs shell option is set using s\bsh\bho\bop\bpt\bt (see the description of
+ Aliases are not expanded when the shell is not interactive, unless the
+ e\bex\bxp\bpa\ban\bnd\bd_\b_a\bal\bli\bia\bas\bse\bes\bs shell option is set using s\bsh\bho\bop\bpt\bt (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 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
- before executing any of the commands on that line. Aliases are
- expanded when a command is read, not when it is executed. Therefore,
- an alias definition appearing on the same line as another command does
- not take effect until the next line of input is read. The commands
+ 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
+ before executing any of the commands on that line. Aliases are
+ expanded when a command is read, not when it is executed. Therefore,
+ an alias definition appearing on the same line as another command does
+ not take effect until the next line of input is read. The commands
following the alias definition on that line are not affected by the new
- alias. This behavior is also an issue when functions are executed.
- Aliases are expanded when a function definition is read, not when the
- function is executed, because a function definition is itself a com-
- pound command. As a consequence, aliases defined in a function are not
- available until after that function is executed. To be safe, always
- put alias definitions on a separate line, and do not use a\bal\bli\bia\bas\bs in com-
- pound commands.
+ 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 com-
+ mand. As a consequence, aliases defined in a function are not avail-
+ able 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.
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
- shell function is used as a simple command name, the list of commands
+ 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
+ shell function is used as a simple command name, the list of commands
associated with that function name is executed. Functions are executed
- in the context of the current shell; no new process is created to
- interpret them (contrast this with the execution of a shell script).
- When a function is executed, the arguments to the function become the
+ in the context of the current shell; no new process is created to
+ interpret 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 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. All other aspects of the shell
- execution environment are identical between a function and its caller
- with the exception that the D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN traps (see the description
- of the t\btr\bra\bap\bp builtin 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) are not inher-
- ited unless the function has been given the t\btr\bra\bac\bce\be attribute (see the
- description of the d\bde\bec\bcl\bla\bar\bre\be builtin below) or the -\b-o\bo f\bfu\bun\bnc\bct\btr\bra\bac\bce\be shell
- option has been enabled with the s\bse\bet\bt builtin (in which case all func-
- tions inherit the D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN traps).
+ 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.
+
+ All other aspects of the shell execution environment are identical
+ between a function and its caller with these exceptions: the D\bDE\bEB\bBU\bUG\bG and
+ R\bRE\bET\bTU\bUR\bRN\bN traps (see the description of the t\btr\bra\bap\bp builtin 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) are not inherited unless the function has been
+ given the t\btr\bra\bac\bce\be attribute (see the description of the d\bde\bec\bcl\bla\bar\bre\be builtin
+ below) or the -\b-o\bo f\bfu\bun\bnc\bct\btr\bra\bac\bce\be shell option has been enabled with the s\bse\bet\bt
+ builtin (in which case all functions inherit the D\bDE\bEB\bBU\bUG\bG and R\bRE\bET\bTU\bUR\bRN\bN
+ traps), and the E\bER\bRR\bR trap is not inherited unless the -\b-o\bo e\ber\brr\brt\btr\bra\bac\bce\be shell
+ option has been enabled.
Variables local to the function may be declared with the l\blo\boc\bca\bal\bl builtin
command. Ordinarily, variables and their values are shared between the
function and its caller.
+ The F\bFU\bUN\bNC\bCN\bNE\bES\bST\bT variable, if set to a numeric value greater than 0,
+ defines a maximum function nesting level. Function invocations that
+ exceed 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
tically-named entries in the environment passed to the shell's chil-
dren. Care should be taken in cases where this may cause a problem.
- Functions may be recursive. No limit is imposed on the number of
+ 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
recursive calls.
A\bAR\bRI\bIT\bTH\bHM\bME\bET\bTI\bIC\bC E\bEV\bVA\bAL\bLU\bUA\bAT\bTI\bIO\bON\bN
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 integer attribute turned on
+ 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.
Constants with a leading 0 are interpreted as octal numbers. A leading
0x or 0X denotes hexadecimal. Otherwise, numbers take the form
- [_\bb_\ba_\bs_\be_\b#]n, where _\bb_\ba_\bs_\be is a decimal number between 2 and 64 representing
- the arithmetic base, and _\bn is a number in that base. If _\bb_\ba_\bs_\be_\b# is omit-
- ted, then base 10 is used. 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 uppercase
- letters may be used interchangeably to represent numbers between 10 and
- 35.
+ [_\bb_\ba_\bs_\be_\b#]n, where the optional _\bb_\ba_\bs_\be is a decimal number between 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, 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 uppercase letters may be used interchangeably to repre-
+ sent numbers between 10 and 35.
Operators are evaluated in order of precedence. Sub-expressions in
parentheses are evaluated first and may override the precedence rules
bolic links and operate on the target of the link, rather than the link
itself.
+ When used with [\b[[\b[, the <\b< and >\b> operators sort lexicographically using
+ the current locale. The t\bte\bes\bst\bt command sorts using ASCII ordering.
+
-\b-a\ba _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists.
-\b-b\bb _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists and is writable.
-\b-x\bx _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists and is executable.
- -\b-O\bO _\bf_\bi_\bl_\be
- True if _\bf_\bi_\bl_\be exists and is owned by the effective user id.
-\b-G\bG _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists and is owned by the effective group id.
-\b-L\bL _\bf_\bi_\bl_\be
True if _\bf_\bi_\bl_\be exists and is a symbolic link.
- -\b-S\bS _\bf_\bi_\bl_\be
- True if _\bf_\bi_\bl_\be exists and is a socket.
-\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-
+ 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
_\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
does not.
- _\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-
- bers.
-\b-o\bo _\bo_\bp_\bt_\bn_\ba_\bm_\be
- True if 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
+ 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).
+ -\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.
-\b-z\bz _\bs_\bt_\br_\bi_\bn_\bg
True if the length of _\bs_\bt_\br_\bi_\bn_\bg is zero.
_\bs_\bt_\br_\bi_\bn_\bg
True if the length of _\bs_\bt_\br_\bi_\bn_\bg is non-zero.
_\bs_\bt_\br_\bi_\bn_\bg_\b1 =\b==\b= _\bs_\bt_\br_\bi_\bn_\bg_\b2
- True if the strings are equal. =\b= may be used in place of =\b==\b= for
- strict POSIX compliance.
+ _\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,
+ 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).
_\bs_\bt_\br_\bi_\bn_\bg_\b1 !\b!=\b= _\bs_\bt_\br_\bi_\bn_\bg_\b2
True if the strings are not equal.
_\bs_\bt_\br_\bi_\bn_\bg_\b1 <\b< _\bs_\bt_\br_\bi_\bn_\bg_\b2
- True if _\bs_\bt_\br_\bi_\bn_\bg_\b1 sorts before _\bs_\bt_\br_\bi_\bn_\bg_\b2 lexicographically in the
- current locale.
+ True if _\bs_\bt_\br_\bi_\bn_\bg_\b1 sorts before _\bs_\bt_\br_\bi_\bn_\bg_\b2 lexicographically.
_\bs_\bt_\br_\bi_\bn_\bg_\b1 >\b> _\bs_\bt_\br_\bi_\bn_\bg_\b2
- True if _\bs_\bt_\br_\bi_\bn_\bg_\b1 sorts after _\bs_\bt_\br_\bi_\bn_\bg_\b2 lexicographically in the
- current locale.
+ True if _\bs_\bt_\br_\bi_\bn_\bg_\b1 sorts after _\bs_\bt_\br_\bi_\bn_\bg_\b2 lexicographically.
_\ba_\br_\bg_\b1 O\bOP\bP _\ba_\br_\bg_\b2
- 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
+ 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.
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
+ When a simple command is executed, the shell performs the following
expansions, assignments, and redirections, from left to right.
- 1. The words that the parser has marked as variable assignments
- (those preceding the command name) and redirections are saved
+ 1. The words that the parser has marked as variable assignments
+ (those preceding the command name) and redirections are saved
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
+ 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.
3. Redirections are performed as described above under R\bRE\bED\bDI\bIR\bRE\bEC\bCT\bTI\bIO\bON\bN.
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
redirections supplied to the e\bex\bxe\bec\bc builtin
+\bo shell aliases defined with a\bal\bli\bia\bas\bs
+\bo various process IDs, including those of background jobs, the
- value of $\b$$\b$, and the value of $\b$P\bPP\bPI\bID\bD
+ 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-
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 posix mode, Bash
+ the -\b-e\be option from the parent shell. When not in _\bp_\bo_\bs_\bi_\bx mode, 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
just those that precede the command name.
When b\bba\bas\bsh\bh invokes an external command, the variable _\b_ is set to the
- full file name of the command and passed to that command in its envi-
- ronment.
+ 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
+ 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
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.
+ return an exit status of 2 to indicate incorrect usage, generally
+ invalid options or missing arguments.
- B\bBa\bas\bsh\bh itself returns the exit status of the last command executed,
- unless a syntax error occurs, in which case it exits with a non-zero
+ B\bBa\bas\bsh\bh itself returns the exit status of the last command executed,
+ unless 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
+ 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
ignores 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
- effect, 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-
+ inherited by the shell from its parent. When job control is not in
+ effect, 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
+ 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
+ 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.
- 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.
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
+ _\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
execution 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
- interface supplied jointly by the system's terminal driver and b\bba\bas\bsh\bh.
+ point. A user typically employs this facility via an interactive
+ interface 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
currently executing jobs, which may be listed with the j\bjo\bob\bbs\bs command.
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
- write to the terminal. Background processes which attempt to read from
- (write to) 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 ter-
- minal driver, which, unless caught, suspends the process.
+ 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 (typ-
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 allows these prompt
- strings to be customized by inserting a number of backslash-escaped
+ 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 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
+ \\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
- inserted into the prompt string; an empty _\bf_\bo_\br_\bm_\ba_\bt results
+ the _\bf_\bo_\br_\bm_\ba_\bt is passed to _\bs_\bt_\br_\bf_\bt_\bi_\bm_\be(3) and the result is
+ inserted into the prompt string; an empty _\bf_\bo_\br_\bm_\ba_\bt results
in a locale-specific time representation. The braces are
required
\\b\e\be an ASCII escape character (033)
\\b\l\bl the basename of the shell's terminal device name
\\b\n\bn newline
\\b\r\br carriage return
- \\b\s\bs the name of the shell, the basename of $\b$0\b0 (the portion
+ \\b\s\bs the name of the shell, the basename of $\b$0\b0 (the portion
following the final slash)
\\b\t\bt the current time in 24-hour HH:MM:SS format
\\b\T\bT the current time in 12-hour HH:MM:SS format
\\b\v\bv the version of b\bba\bas\bsh\bh (e.g., 2.00)
\\b\V\bV the release of b\bba\bas\bsh\bh, version + patch level (e.g., 2.00.0)
\\b\w\bw the current working directory, with $\b$H\bHO\bOM\bME\bE abbreviated
- with a tilde (uses the $\b$P\bPR\bRO\bOM\bMP\bPT\bT_\b_D\bDI\bIR\bRT\bTR\bRI\bIM\bM variable)
+ with a tilde (uses the value of the P\bPR\bRO\bOM\bMP\bPT\bT_\b_D\bDI\bIR\bRT\bTR\bRI\bIM\bM vari-
+ able)
\\b\W\bW the basename of the current working directory, with $\b$H\bHO\bOM\bME\bE
abbreviated with a tilde
\\b\!\b! the history number of this command
\\b\$\b$ if the effective UID is 0, a #\b#, otherwise a $\b$
\\b\_\bn_\bn_\bn the character corresponding to the octal number _\bn_\bn_\bn
\\b\\\b\ a backslash
- \\b\[\b[ begin a sequence of non-printing characters, which could
- be used to embed a terminal control sequence into the
+ \\b\[\b[ begin a sequence of non-printing characters, which could
+ be used to embed a terminal control sequence into the
prompt
\\b\]\b] end a sequence of non-printing characters
- The command number and the history number are usually different: the
- history number of a command is its position in the history list, which
- may include commands restored from the history file (see H\bHI\bIS\bST\bTO\bOR\bRY\bY
- below), while the command number is the position in the sequence of
- commands executed during the current shell session. After the string
- is decoded, it is expanded via parameter expansion, command substitu-
- tion, 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
+ The command number and the history number are usually different: the
+ history number of a command is its position in the history list, which
+ may include commands restored from the history file (see H\bHI\bIS\bST\bTO\bOR\bRY\bY
+ below), while the command number is the position in the sequence of
+ commands executed during the current shell session. After the string
+ is decoded, it is expanded via parameter expansion, command substitu-
+ tion, 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).
R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE
- This is the library that handles reading input when using an interac-
+ 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
+ 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
- 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
+ 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
+ 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-
- boards without a _\bm_\be_\bt_\ba key, M-_\bx means ESC _\bx, i.e., press the Escape key
+ 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-
+ 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
- means ESC-Control-_\bx, or press the Escape key then hold the Control key
+ 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
+ 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
+ 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
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_\bp_\bu_\bt_\br_\bc. When a program which uses the readline library starts up,
+ 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_\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 con-
+ 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 con-
structs. 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 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
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-
+ 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.
If set to O\bOn\bn, readline attempts to bind the control characters
treated specially by the kernel's terminal driver to their read-
line equivalents.
+ 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
+ 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.
+ 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 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
mapped to s\bse\bel\blf\bf-\b-i\bin\bns\bse\ber\brt\bt.
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\bec\bch\bho\bo-\b-c\bco\bon\bnt\btr\bro\bol\bl-\b-c\bch\bha\bar\bra\bac\bct\bte\ber\brs\bs (\b(O\bOn\bn)\b)
+ When set to O\bOn\bn, on operating systems that indicate they support
+ it, readline echoes a character corresponding to a signal gener-
+ ated from the keyboard.
+ 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\bOf\bff\bf)\b)
+ When set to O\bOn\bn, readline will configure the terminal in a way
+ that will enable it to insert each paste into the editing buffer
+ as a single string of characters, instead of treating each char-
+ acter as if it had been read from the keyboard. This can pre-
+ vent pasted characters from being interpreted as editing com-
+ mands.
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
+ pad when it is called. Some systems need this to enable the
arrow 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
+ 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
+ If set to O\bOn\bn, tilde expansion is performed when readline
attempts word completion.
h\bhi\bis\bst\bto\bor\bry\by-\b-p\bpr\bre\bes\bse\ber\brv\bve\be-\b-p\bpo\boi\bin\bnt\bt (\b(O\bOf\bff\bf)\b)
- If set to o\bon\bn, the history code attempts to place point at the
- same location on each history line retrieved with p\bpr\bre\bev\bvi\bio\bou\bus\bs-\b-h\bhi\bis\bs-\b-
+ If set to O\bOn\bn, the history code attempts to place point at the
+ same location on each history line retrieved with p\bpr\bre\bev\bvi\bio\bou\bus\bs-\b-h\bhi\bis\bs-\b-
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(0\b0)\b)
- Set the maximum number of history entries saved in the history
- list. If set to zero, the number of entries in the history list
- is not limited.
+ 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,
+ the number of history entries is not limited. By default, the
+ number of history entries is not limited.
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,
+ 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
+ becomes longer than the screen width rather than wrapping to a
new line.
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 high bit from the characters it reads),
+ If set to O\bOn\bn, readline will enable eight-bit input (that is, it
+ will not strip the high bit from the characters it reads),
regardless 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.
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-
+ 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-
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
- 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
+ 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
value of e\bed\bdi\bit\bti\bin\bng\bg-\b-m\bmo\bod\bde\be also affects the default keymap.
+ e\bem\bma\bac\bcs\bs-\b-m\bmo\bod\bde\be-\b-s\bst\btr\bri\bin\bng\bg (\b(@\b@)\b)
+ 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 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-
+ trol sequence into the mode string.
+ 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
+ received 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,
+ 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
+ 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\bar\brk\bk-\b-d\bdi\bir\bre\bec\bct\bto\bor\bri\bie\bes\bs (\b(O\bOn\bn)\b)
If set to O\bOn\bn, completed directory names have a slash appended.
m\bma\bar\brk\bk-\b-m\bmo\bod\bdi\bif\bfi\bie\bed\bd-\b-l\bli\bin\bne\bes\bs (\b(O\bOf\bff\bf)\b)
- If set to O\bOn\bn, history lines that have been modified are dis-
+ If set to O\bOn\bn, history lines that have been modified are dis-
played with a preceding asterisk (*\b*).
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 (\b(O\bOf\bff\bf)\b)
If set to O\bOn\bn, completed names which are symbolic links to direc-
- tories have a slash appended (subject to the value of
+ tories have a slash appended (subject to the value of
m\bma\bar\brk\bk-\b-d\bdi\bir\bre\bec\bct\bto\bor\bri\bie\bes\bs).
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, unless the leading `.' is supplied by the
- user in the filename to be completed.
+ 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
+ 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
+ through the list.
o\bou\but\btp\bpu\but\bt-\b-m\bme\bet\bta\ba (\b(O\bOf\bff\bf)\b)
- If set to O\bOn\bn, readline will display characters with the eighth
+ If set to O\bOn\bn, readline will display characters with the eighth
bit set directly rather than as a meta-prefixed escape sequence.
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-
sorted horizontally in alphabetical order, rather than down the
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
+ 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-
tory lines may be modified and retain individual undo lists
across calls to r\bre\bea\bad\bdl\bli\bin\bne\be.
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
+ 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
instead 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 character to the beginning of the prompt
+ indicating the editing mode: emacs (@), vi command (:) or vi
+ insertion (+).
+ 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,
+ 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)
+ 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 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 control sequence into the mode string.
+ 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)
+ 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 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 control sequence into the mode string.
v\bvi\bis\bsi\bib\bbl\ble\be-\b-s\bst\bta\bat\bts\bs (\b(O\bOf\bff\bf)\b)
- If set to O\bOn\bn, a character denoting a file's type as reported by
- _\bs_\bt_\ba_\bt(2) is appended to the filename when listing possible com-
+ If set to O\bOn\bn, a character denoting a file's type as reported by
+ _\bs_\bt_\ba_\bt(2) is appended to the filename when listing possible com-
pletions.
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
+ 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.
- $\b$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 extends to the end of the line;
+ $\b$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 extends to the end of the line;
no characters 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
+ 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.
- 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
- of the =\b= is tested against the both 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,
+ 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,
for instance.
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
- library sets the _\ba_\bp_\bp_\bl_\bi_\bc_\ba_\bt_\bi_\bo_\bn _\bn_\ba_\bm_\be, and an initialization
+ library 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
- Bash:
+ 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
# Quote the current or previous word
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 follow-
+ 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
+ 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
+ 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
+ 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 termi-
+ 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
+ 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
+ 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
+ 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
+ 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
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
+ 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.
c\bcl\ble\bea\bar\br-\b-s\bsc\bcr\bre\bee\ben\bn (\b(C\bC-\b-l\bl)\b)
- Clear the screen leaving the current line at the top of the
- screen. With an argument, refresh the current line without
+ Clear the screen leaving the current 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
+ 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.
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 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 forward starting at the current line and moving `down'
+ 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.
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
+ 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
+ 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 argument _\bn is computed, the argument is extracted as if the
+ 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 an 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 argument
- of each line in turn. The history expansion facilities are used
- to extract the last argument, as if the "!$" history expansion
- had been specified.
+ Insert the last argument to the previous command (the last word
+ of the previous history entry). With a numeric argument, behave
+ exactly like y\bya\ban\bnk\bk-\b-n\bnt\bth\bh-\b-a\bar\brg\bg. Successive calls to y\bya\ban\bnk\bk-\b-l\bla\bas\bst\bt-\b-a\bar\brg\bg
+ move back through the history list, inserting the last word (or
+ the word specified by the argument to the first call) of each
+ line in turn. Any numeric argument supplied to these successive
+ calls determines the direction to move through the history. A
+ negative argument switches the direction through the history
+ (back or forward). The history expansion facilities are used to
+ extract the last word, as if the "!$" 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 as the shell does. This performs alias and his-
tory expansion as well as all of the shell word expansions. 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 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\bXP\bPA\bAN\bNS\bSI\bIO\bON\bN below for a description of history expansion.
$\b$E\bED\bDI\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 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 point is at the beginning of
- the line, there are no characters in the line, and the last
- character typed was not bound to d\bde\bel\ble\bet\bte\be-\b-c\bch\bha\bar\br, then return E\bEO\bOF\bF.
+ 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
+ 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
+ Uppercase the current (or following) word. With a negative
argument, 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
+ Lowercase the current (or following) word. With a negative
argument, 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
+ Capitalize the current (or following) word. With a negative
argument, 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-
+ 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
+ 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
+ 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
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
+ 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 (\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
+ 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.
- 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 (\b(M\bM-\b-R\bRu\bub\bbo\bou\but\bt)\b)
- Kill the word behind point. Word boundaries are the same as
+ 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
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-
+ 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 follow-
+ 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
+ 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-
- 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
- numeric argument, but is otherwise ignored. As a special case,
- if this command is immediately followed by a character that is
- neither a digit or minus sign, the argument count for the next
- command is multiplied by four. The argument count is initially
- one, so executing this function the first time makes the argu-
+ 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
+ numeric argument, but is otherwise ignored. As a special case,
+ if this command is immediately followed by a character that is
+ neither 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
+ 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
+ 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
- moves _\bn positions forward in the list of matches; a negative
- argument may be used to move backward through the list. This
- command is intended to be bound to T\bTA\bAB\bB, but is unbound by
+ moves _\bn positions forward in the list of matches; a negative
+ argument may be used to move backward through the list. This
+ command is intended to be bound to 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.
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
+ 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)
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
+ 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)
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
+ 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 count searches for previous occur-
+ that character. A negative count searches for previous occur-
rences.
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 count searches for subse-
+ A character is read and point is moved to the previous occur-
+ rence of that character. A negative count searches for subse-
quent 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.
+ 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
+ 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-
+ 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
+ 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.
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
- expansion, with an asterisk implicitly appended. This pattern
- is used to generate a list of matching file names for possible
+ The word before point is treated as a pattern for pathname
+ expansion, with an asterisk implicitly appended. This pattern
+ is used to generate a list of matching filenames for possible
completions.
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
- expansion, and the list of matching file names is inserted,
- replacing the word. If a numeric argument is supplied, an
+ The word before point is treated as a pattern for pathname
+ expansion, and the list of matching filenames is inserted,
+ replacing 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
- numeric argument is supplied, an asterisk is appended before
+ 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-
+ 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
+ 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
+ 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.
+ 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 pro-
- grammable completion facilities are invoked.
-
- First, the command name is identified. If a compspec has been defined
- for that command, the compspec is used to generate the list of possible
- completions for the word. If the command word is a full pathname, a
- compspec for the full pathname is searched for first. If no compspec
- is found for the full pathname, an attempt is made to find a compspec
- for the portion following the final slash.
+ 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.
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-
-\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 filename expansion pattern to the -\b-G\bG
+ Any completions specified by a pathname expansion pattern to the -\b-G\bG
option 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.
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 is the name of the command whose arguments are being
- completed, the second argument is the word being completed, and the
- third argument is the word preceding the word being completed on the
- current command line. No filtering of the generated completions
- against the word being completed is performed; the function or command
- has complete freedom in generating the matches.
+ first argument ($\b$1\b1) is the name of the command whose arguments are
+ being completed, the second argument ($\b$2\b2) is the word being completed,
+ and the third argument ($\b$3\b3) is the word preceding the word being 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.
+ 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
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.
+ 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
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
+ changes the compspec associated with the command on which completion 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
+ 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
+ default completion function would load completions dynamically:
+
+ _completion_loader()
+ {
+ . "/etc/bash_completion.d/$1.sh" >/dev/null 2>&1 && return 124
+ }
+ complete -D -F _completion_loader -o bashdefault -o default
+
+
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
provides access to the _\bc_\bo_\bm_\bm_\ba_\bn_\bd _\bh_\bi_\bs_\bt_\bo_\br_\by, the list of commands previously
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. When the his-
- tory file is read, lines beginning with the history comment character
- followed immediately by a digit are interpreted as timestamps for the
- preceding history line. These timestamps are optionally displayed
- depending on the value of the H\bHI\bIS\bST\bTT\bTI\bIM\bME\bEF\bFO\bOR\bRM\bMA\bAT\bT variable. When an inter-
- active shell exits, the last $\b$H\bHI\bIS\bST\bTS\bSI\bIZ\bZE\bE lines are copied from the his-
- tory 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 over-
- written. If H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE is unset, or if the history file is unwritable,
- the history is not saved. If the 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 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\bTF\bFI\bIL\bLE\bES\bSI\bIZ\bZE\bE is not set, no trunca-
- tion is performed.
-
- 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
+ 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 pre-
+ ceding 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 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
- manipulate the history file. When using command-line editing, search
- commands are available in each editing mode that provide access to the
+ t\bto\bor\bry\by builtin may be used to display or modify the history list and
+ manipulate the history file. When using command-line editing, search
+ commands are available in each editing mode that provide access to the
history list.
- The shell allows control over which commands are saved on the history
+ The shell allows control over which commands are saved on the history
list. The 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 may be set 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
+ 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
options.
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.\b. 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.\b. 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
perform history expansion by default.
History expansions introduce words from the history list into the input
- stream, making it easy to repeat commands, insert the arguments to a
+ stream, making it easy to repeat commands, insert the arguments to a
previous command into the current input line, or fix errors in previous
commands quickly.
- History expansion is performed immediately after a complete line is
- read, before the shell breaks it into words. It takes place in two
- parts. The first is to determine which line from the history list to
+ History expansion is performed immediately after a complete line is
+ read, before the shell breaks it into words. It takes place in two
+ parts. The first is to determine which line from the history list to
use during substitution. The second is to select portions of that line
for inclusion into the current one. The line selected from the history
- is the _\be_\bv_\be_\bn_\bt, and the portions of that line that are acted upon are
- _\bw_\bo_\br_\bd_\bs. Various _\bm_\bo_\bd_\bi_\bf_\bi_\be_\br_\bs are available to manipulate the selected
+ is the _\be_\bv_\be_\bn_\bt, and the portions of that line that are acted upon are
+ _\bw_\bo_\br_\bd_\bs. Various _\bm_\bo_\bd_\bi_\bf_\bi_\be_\br_\bs are available to manipulate the selected
words. The line is broken into words in the same fashion as when read-
- ing input, so that several _\bm_\be_\bt_\ba_\bc_\bh_\ba_\br_\ba_\bc_\bt_\be_\br-separated words surrounded by
- quotes are considered one word. History expansions are introduced by
- the appearance of the history expansion character, which is !\b! by
- default. Only backslash (\\b\) and single quotes can quote the history
- expansion character.
-
- Several characters inhibit history expansion if found immediately fol-
- lowing the history expansion character, even if it is unquoted: space,
- tab, newline, carriage return, and =\b=. If the e\bex\bxt\btg\bgl\blo\bob\bb shell option is
+ ing 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. History expansions are introduced by
+ the appearance of the history expansion character, which is !\b! by
+ default. 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, and =\b=. If the e\bex\bxt\btg\bgl\blo\bob\bb shell option is
enabled, (\b( will also inhibit expansion.
- 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
- option is enabled (see the description of the s\bsh\bho\bop\bpt\bt builtin), and r\bre\bea\bad\bd-\b-
- l\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 sub-
- stitution will be reloaded into the r\bre\bea\bad\bdl\bli\bin\bne\be editing buffer for correc-
- tion. 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
+ 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
+ option 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.
+ An event designator is a reference to a command line entry in the his-
+ tory list. Unless the reference is absolute, events are relative to
+ the current position in the history list.
!\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 line minus _\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!_\bs_\bt_\br_\bi_\bn_\bg
- Refer to the most recent command starting with _\bs_\bt_\br_\bi_\bn_\bg.
+ 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 containing _\bs_\bt_\br_\bi_\bn_\bg. The trail-
- ing ?\b? may be omitted if _\bs_\bt_\br_\bi_\bn_\bg is followed immediately by a new-
- line.
+ 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.
^\b^_\bs_\bt_\br_\bi_\bn_\bg_\b1^\b^_\bs_\bt_\br_\bi_\bn_\bg_\b2^\b^
- Quick substitution. Repeat the last 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\bd-\b-
- i\bif\bfi\bie\ber\brs\bs below).
+ 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 sepa-
+ 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.
_\bn The _\bnth word.
^\b^ The first argument. That is, word 1.
- $\b$ The last argument.
+ $\b$ The last word. This is usually the last argument, but will
+ expand to the zeroth word if there is only one word in the line.
%\b% The word matched by the most recent `?_\bs_\bt_\br_\bi_\bn_\bg?' search.
_\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$'.
After the optional word designator, there may appear a sequence of one
or more of the following modifiers, each preceded by a `:'.
- h\bh Remove a trailing file name component, leaving only the head.
- t\bt Remove all leading file name components, leaving the tail.
+ h\bh Remove a trailing filename component, leaving only the head.
+ t\bt Remove all leading filename components, leaving the tail.
r\br Remove a trailing suffix of the form _\b._\bx_\bx_\bx, leaving the basename.
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
+ x\bx Quote the substituted words as with q\bq, but break into words at
b\bbl\bla\ban\bnk\bks\bs and newlines.
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
- line. Any delimiter can be used in place of /. The final
- delimiter is optional if it is the last character of the event
- line. The delimiter may be quoted in _\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 sin-
- gle 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 substitu-
+ Substitute _\bn_\be_\bw for the first occurrence of _\bo_\bl_\bd in the event
+ line. Any delimiter can be used in place of /. The final
+ delimiter is optional if it is the last character of the event
+ line. The delimiter may be quoted in _\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 sin-
+ gle 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 substitu-
tions took place, the last _\bs_\bt_\br_\bi_\bn_\bg in a !\b!?\b?_\bs_\bt_\br_\bi_\bn_\bg[\b[?\b?]\b] search.
&\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
+ 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' modifier once to each word in the event
+ G\bG Apply the following `s\bs' modifier once to each word in the event
line.
S\bSH\bHE\bEL\bLL\bL B\bBU\bUI\bIL\bLT\bTI\bIN\bN C\bCO\bOM\bMM\bMA\bAN\bND\bDS\bS
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 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, b\bbr\bre\bea\bak\bk, c\bco\bon\bnt\bti\bin\bnu\bue\be, l\ble\bet\bt,
- and s\bsh\bhi\bif\bft\bt builtins accept and process arguments beginning with -\b- with-
- out 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 interpretation.
+ options. The :\b:, t\btr\bru\bue\be, f\bfa\bal\bls\bse\be, and t\bte\bes\bst\bt 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-
+ 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. A zero exit code is
- returned.
+ 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
environment 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. The file searched for in P\bPA\bAT\bTH\bH need not be executable.
+ 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. 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, the current directory is
searched 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_\bm_\be_\bn_\bt_\bs are supplied, they become the posi-
tional parameters when _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is executed. Otherwise the
- positional parameters are unchanged. The return status is the
- status of the last command exited within the script (0 if no
- commands are executed), and false if _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is not found or
+ positional parameters are unchanged. If the -\b-T\bT option is
+ enabled, s\bso\bou\bur\brc\bce\be 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
+ s\bso\bou\bur\brc\bce\be, and s\bso\bou\bur\brc\bce\be unsets the D\bDE\bEB\bBU\bUG\bG trap while it executes. 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 s\bso\bou\bur\brc\bce\be 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
+ 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.
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
+ 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
+ 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\bV]
+ 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] [-\b-q\bq _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn] [-\b-u\bu _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn] [-\b-r\br _\bk_\be_\by_\bs_\be_\bq]
b\bbi\bin\bnd\bd [-\b-m\bm _\bk_\be_\by_\bm_\ba_\bp] -\b-f\bf _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be
b\bbi\bin\bnd\bd [-\b-m\bm _\bk_\be_\by_\bm_\ba_\bp] -\b-x\bx _\bk_\be_\by_\bs_\be_\bq:_\bs_\bh_\be_\bl_\bl_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd
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 _\br_\be_\ba_\bd_\bl_\bi_\bn_\be_\b-_\bc_\bo_\bm_\bm_\ba_\bn_\bd
- 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
- appear in _\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'.
+ 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
+ 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
+ appear in _\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; _\be_\bm_\ba_\bc_\bs is
- equivalent to _\be_\bm_\ba_\bc_\bs_\b-_\bs_\bt_\ba_\bn_\bd_\ba_\br_\bd.
+ _\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.
command changes the value of R\bRE\bEA\bAD\bDL\bLI\bIN\bNE\bE_\b_L\bLI\bIN\bNE\bE or R\bRE\bEA\bAD\bD-\b-
L\bLI\bIN\bNE\bE_\b_P\bPO\bOI\bIN\bNT\bT, 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
+ input.
The return value is 0 unless an unrecognized option is given or
an error occurred.
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-
plied as _\be_\bx_\bp_\br, c\bca\bal\bll\ble\ber\br displays the line number, subroutine name,
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|-\b-P\bP] [_\bd_\bi_\br]
- Change the current directory to _\bd_\bi_\br. The variable H\bHO\bOM\bME\bE is the
- default _\bd_\bi_\br. The variable C\bCD\bDP\bPA\bAT\bTH\bH defines the search path for
- the directory containing _\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 says to use the physical directory structure instead of
- following symbolic links (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 fol-
- lowed. An argument of -\b- is equivalent to $\b$O\bOL\bLD\bDP\bPW\bWD\bD. 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. The return value is true if the directory was success-
- fully changed; false otherwise.
+ 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. Any addi-
+ tional arguments following _\bd_\bi_\br are ignored. 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 success-
+ fully 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 associated with a
+ file as a directory. An argument of -\b- is converted to $\b$O\bOL\bLD\bDP\bPW\bWD\bD
+ before the directory change is attempted. If a non-empty direc-
+ tory 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.
+ 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
+ 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
option 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 file name
+ 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
various shell variables set by the programmable completion
facilities, while available, will not have useful values.
- The matches will be generated in the same way as if the pro-
- grammable completion code had generated them directly from a
- completion specification with the same flags. If _\bw_\bo_\br_\bd is speci-
- fied, only those completions matching _\bw_\bo_\br_\bd will be displayed.
+ 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,
+ only those completions matching _\bw_\bo_\br_\bd will be displayed.
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-E\bE] [-\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]
+ 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\bE] [-\b-A\bA _\ba_\bc_\bt_\bi_\bo_\bn] [-\b-G\bG _\bg_\bl_\bo_\bb_\b-
+ _\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-E\bE] [_\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
+ c\bco\bom\bmp\bpl\ble\bet\bte\be -\b-p\bpr\br [-\b-D\bDE\bE] [_\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 spec-
- ification for each _\bn_\ba_\bm_\be, or, if no _\bn_\ba_\bm_\bes are supplied, all com-
- pletion specifications. The -\b-E\bE option indicates that the
- remaining options and actions should apply to ``empty'' command
- completion; that is, completion attempted on a blank line.
-
- The process of applying these completion specifications when
- word completion is attempted is described above under 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.
-
- 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-
+ 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 the
+ remaining options and actions should apply to the ``default''
+ command completion; that is, completion attempted on a command
+ for which no completion has previously been defined. The -\b-E\bE
+ option indicates that the remaining options and actions should
+ apply to ``empty'' command completion; that is, completion
+ attempted on a blank line.
+
+ The process of applying these completion specifications when
+ word completion is attempted is described above under 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
+ 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-
+ 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.
+ 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
+ completions alphabetically.
n\bno\bos\bsp\bpa\bac\bce\be Tell readline not to append a space (the
default) to words completed at the end of the
line.
-\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\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.
v\bva\bar\bri\bia\bab\bbl\ble\be
Names of all shell variables. May also be spec-
ified as -\b-v\bv.
- -\b-G\bG _\bg_\bl_\bo_\bb_\bp_\ba_\bt
- The filename expansion pattern _\bg_\bl_\bo_\bb_\bp_\ba_\bt is expanded to
- generate the possible completions.
- -\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. The possible completions are the members
- of the resultant list which match the word being com-
- pleted.
-\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
+ _\bc_\bo_\bm_\bm_\ba_\bn_\bd is executed in a subshell environment, and its
output is used as the possible completions.
-\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 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-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 filename 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
- case, any completion not matching _\bf_\bi_\bl_\bt_\be_\br_\bp_\ba_\bt is removed.
+ 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$1\b1) is the name of the command whose
+ arguments are being completed, the second argument ($\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
+ current command line. When it finishes, the possible
+ completions are retrieved from the value of the C\bCO\bOM\bMP\bPR\bRE\bE-\b-
+ P\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
+ 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. The possible completions are the members
+ of the resultant list which match the word being com-
+ pleted.
+ -\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.
+ 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
+ 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,
an option other than -\b-p\bp or -\b-r\br is supplied without a _\bn_\ba_\bm_\be argu-
for a _\bn_\ba_\bm_\be for which no specification exists, or an error occurs
adding a completion specification.
- c\bco\bom\bmp\bpo\bop\bpt\bt [-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn] [+\b+o\bo _\bo_\bp_\bt_\bi_\bo_\bn] [_\bn_\ba_\bm_\be]
+ c\bco\bom\bmp\bpo\bop\bpt\bt [-\b-o\bo _\bo_\bp_\bt_\bi_\bo_\bn] [-\b-D\bDE\bE] [+\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_\bt_\bi_\bo_\bns, or for the currently-execution completion if no _\bn_\ba_\bm_\bes
+ _\bo_\bp_\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
options 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
- described above.
+ described above. The -\b-D\bD option indicates that the remaining
+ 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 the
+ remaining options should apply to ``empty'' command completion;
+ that is, completion attempted on a blank line.
- 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 comple-
- tion specification exists, or an output error occurs.
+ 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
- enclosing loops, the last enclosing loop (the ``top-level''
+ 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
+ enclosing 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\bFi\bil\blr\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\bFi\bil\blr\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
+ d\bde\bec\bcl\bla\bar\bre\be [-\b-a\baA\bAf\bfF\bFg\bgi\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\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 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 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 display of function defi-
- nitions; 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 the function is defined are dis-
- played as well. The -\b-F\bF option implies -\b-f\bf. The following
- options can be used to restrict output to variables with the
+ 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
+ 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 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 follow-
+ ing 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
above).
above).
-\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 )\b) is performed when the
- variable is assigned a value.
+ 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
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
+ defined by the value of _\bn_\ba_\bm_\be. All references, assign-
+ ments, and attribute modifications to _\bn_\ba_\bm_\be, except for
+ 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
Using `+' instead of `-' turns off the attribute instead, with
the exceptions that +\b+a\ba may not be used to destroy an array vari-
- able and +\b+r\br w\bwi\bil\bll\bl n\bno\bot\bt r\bre\bem\bmo\bov\bve\be t\bth\bhe\be r\bre\bea\bad\bdo\bon\bnl\bly\by a\bat\btt\btr\bri\bib\bbu\but\bte\be.\b. W\bWh\bhe\ben\bn u\bus\bse\bed\bd
- i\bin\bn a\ba f\bfu\bun\bnc\bct\bti\bio\bon\bn,\b, m\bma\bak\bke\bes\bs e\bea\bac\bch\bh _\bn_\ba_\bm_\be l\blo\boc\bca\bal\bl,\b, a\bas\bs w\bwi\bit\bth\bh t\bth\bhe\be l\blo\boc\bca\bal\bl command.
- If a variable name is followed by =_\bv_\ba_\bl_\bu_\be, the value of the vari-
- able is set to _\bv_\ba_\bl_\bu_\be. 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 assign a value to an
- array variable without using the compound assignment syntax (see
- A\bAr\brr\bra\bay\bys\bs above), 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 read-
- only variable, an attempt is made to turn off array status for
- an array variable, or an attempt is made to display a non-exis-
- tent function with -\b-f\bf.
-
- d\bdi\bir\brs\bs [\b[+\b+_\bn]\b] [\b[-\b-_\bn]\b] [\b[-\b-c\bcp\bpl\blv\bv]\b]
- Without options, displays the list of currently remembered
- directories. The default display is on a single line with
- directory 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.
- +\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
- list shown by d\bdi\bir\brs\bs when invoked without options, starting
- with zero.
+ able 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 vari-
+ able 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
+ assign a value to a readonly variable, an attempt is made to
+ assign a value to an array variable without using the compound
+ assignment syntax (see A\bAr\brr\bra\bay\bys\bs above), one of the _\bn_\ba_\bm_\be_\bs is not a
+ valid shell variable name, an attempt is made to turn off read-
+ only 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
+ directories. The default display is on a single line with
+ directory 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 directory in the stack.
-\b-c\bc Clears the directory stack by deleting all of the
entries.
- -\b-l\bl Produces a longer listing; the default listing format
- uses a tilde to denote the home directory.
+ -\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-
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
+ 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
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 ...]
- Without options, each _\bj_\bo_\bb_\bs_\bp_\be_\bc is removed from the table of
- active jobs. If _\bj_\bo_\bb_\bs_\bp_\be_\bc is not present, and neither -\b-a\ba n\bno\bor\br -\b-r\br
- i\bis\bs s\bsu\bup\bpp\bpl\bli\bie\bed\bd,\b, t\bth\bhe\be s\bsh\bhe\bel\bll\bl'\b's\bs n\bno\bot\bti\bio\bon\bn o\bof\bf t\bth\bhe\be _\bc_\bu_\br_\br_\be_\bn_\bt _\bj_\bo_\bb i\bis\bs u\bus\bse\bed\bd.\b. I\bIf\bf
- t\bth\bhe\be -\b-h\bh o\bop\bpt\bti\bio\bon\bn i\bis\bs g\bgi\biv\bve\ben\bn,\b, e\bea\bac\bch\bh _\bj_\bo_\bb_\bs_\bp_\be_\bc is not removed from the ta-
- ble, 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 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 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 restricts
- operation to running jobs. The return value is 0 unless a _\bj_\bo_\bb_\b-
- _\bs_\bp_\be_\bc does not specify a valid job.
+ 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_\b-
+ _\bs_\bp_\be_\bc argument 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 always 0. If -\b-n\bn is specified, the trailing
- newline is suppressed. If the -\b-e\be option is given, interpreta-
- tion of the following backslash-escaped characters is enabled.
- The -\b-E\bE option disables the interpretation of these escape char-
- acters, 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 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:
+ 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 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\e\be an escape character
+ \\b\e\be
+ \\b\E\bE an escape character
\\b\f\bf form feed
\\b\n\bn new line
\\b\r\br carriage return
\\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
+ 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
+ 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
+ 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
enabled. 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
+ 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.
- The -\b-d\bd option will delete a builtin previously loaded with -\b-f\bf.
+ 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 argu-
- ments, the list consists of all enabled shell builtins. If -\b-n\bn
- is supplied, only disabled builtins are printed. If -\b-a\ba is sup-
- plied, the list printed includes all builtins, with an indica-
- tion 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. The return
- value is 0 unless a _\bn_\ba_\bm_\be is not a shell builtin or there is an
+ ments, the list consists of all enabled shell builtins. If -\b-n\bn
+ is supplied, only disabled builtins are printed. If -\b-a\ba is sup-
+ plied, the list printed includes all builtins, with an indica-
+ tion 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. 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
+ ning of the zeroth argument passed to _\bc_\bo_\bm_\bm_\ba_\bn_\bd. This is what
_\bl_\bo_\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
+ 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 shell option e\bex\bxe\bec\bcf\bfa\bai\bil\bl is enabled, in which case it
- returns failure. An interactive shell returns failure if the
+ 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. If _\bc_\bo_\bm_\bm_\ba_\bn_\bd is not specified, any redi-
rections take effect in the current shell, and the return status
- is 0. If there is a redirection error, the return status is 1.
+ 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 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 all names that are
- exported in this shell 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 supplied with a _\bn_\ba_\bm_\be that is not a func-
- tion.
+ 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-
+ plied with a _\bn_\ba_\bm_\be that is not a function.
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]
- Fix Command. In the first form, a range of commands from _\bf_\bi_\br_\bs_\bt
- to _\bl_\ba_\bs_\bt is selected from the history list. _\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 cur-
- rent command number). 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 spec-
- ified 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-
+ 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). 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 other-
+ wise. If _\bf_\bi_\br_\bs_\bt is not specified it is set to the previous com-
+ mand 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. 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 com-
- mand.
+ 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 intepreted 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
- invalid 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
+ invalid 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
+ 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
+ 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
+ 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_\bs]
- 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
- 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
+ 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
+ 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 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
- option 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 automati-
- cally; it must be manually reset between multiple calls to
+ 1 each time the shell or a shell script is invoked. When an
+ option 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 automati-
+ cally; 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 parame-
ters is to be used.
- When the end of options is encountered, g\bge\bet\bto\bop\bpt\bts\bs exits with a
- return value greater than zero. O\bOP\bPT\bTI\bIN\bND\bD is set to the index of
- the first non-option argument, and n\bna\bam\bme\be is set to ?.
+ When the end of options is encountered, g\bge\bet\bto\bop\bpt\bts\bs exits with a
+ return 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
+ g\bge\bet\bto\bop\bpt\bts\bs normally parses the positional parameters, but if more
arguments are given in _\ba_\br_\bg_\bs, g\bge\bet\bto\bop\bpt\bts\bs parses those instead.
- 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-
+ 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
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]
- For each _\bn_\ba_\bm_\be, the full file name of the command is determined
- by searching the directories in $\b$P\bPA\bAT\bTH\bH and remembered. If the -\b-p\bp
- option is supplied, no path search is performed, and _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be is
- used as the full file name of the command. The -\b-r\br option causes
- the shell to forget all remembered locations. 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 for-
- mat 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 return status is true unless a _\bn_\ba_\bm_\be is not found
- or an invalid option is supplied.
+ 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, no path search is performed, and _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be
+ is used as the full filename of the command. The -\b-r\br option
+ causes the shell to forget all remembered locations. 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 argu-
+ ments 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 dis-
+ played in a format that may be reused as input. If no arguments
+ are given, or if only -\b-l\bl is supplied, information about remem-
+ bered commands is printed. 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
format
-\b-s\bs Display only a short usage synopsis for each _\bp_\ba_\bt_\bt_\be_\br_\bn
- The return status is 0 unless no command matches _\bp_\ba_\bt_\bt_\be_\br_\bn.
+
+ The return status is 0 unless no command matches _\bp_\ba_\bt_\bt_\be_\br_\bn.
h\bhi\bis\bst\bto\bor\bry\by [\b[_\bn]\b]
h\bhi\bis\bst\bto\bor\bry\by -\b-c\bc
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\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. Options, if supplied, have the
+ _\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. 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.
- -\b-a\ba Append the ``new'' history lines (history lines entered
- since the beginning of the current b\bba\bas\bsh\bh session) to the
+ -\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
appended 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 use them as the
- current history.
- -\b-w\bw Write the current history to the history file, overwrit-
- ing the history file's contents.
+ -\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
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 is set, the time stamp information associ-
- ated with each history entry is written to the history 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 previous history line. 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 is supplied as an
- argument to -\b-d\bd, or the history expansion supplied as an argument
- to -\b-p\bp fails.
+ 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 is sup-
+ plied as an argument to -\b-d\bd, or the history expansion supplied 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-
lowing meanings:
-\b-l\bl List process IDs in addition to the normal information.
- -\b-p\bp List only the process ID of the job's process group
+ -\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
leader.
- -\b-n\bn Display information only about jobs that have changed
- status since the user was last notified of their status.
- -\b-r\br Restrict output to running jobs.
- -\b-s\bs Restrict output to stopped jobs.
+ -\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
+ 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
+ _\bc_\bo_\bm_\bm_\ba_\bn_\bd or _\ba_\br_\bg_\bs with the corresponding process group ID, and
executes _\bc_\bo_\bm_\bm_\ba_\bn_\bd passing it _\ba_\br_\bg_\bs, returning its exit status.
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 [_\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
+ 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. k\bki\bil\bll\bl returns true
- if at least one signal was successfully sent, or false if an
- error occurs or an invalid option is encountered.
+ -\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
+ option 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). If the last _\ba_\br_\bg evaluates to 0, l\ble\bet\bt returns
- 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] ...]
+ 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. 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.
+ 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 are
+ restored to their original values when the function returns.
+ 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-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-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 array variable _\ba_\br_\br_\ba_\by, or
- from file descriptor _\bf_\bd if the -\b-u\bu option is supplied. The vari-
- able M\bMA\bAP\bPF\bFI\bIL\bLE\bE is the default _\ba_\br_\br_\ba_\by. Options, if supplied, have
- the following meanings:
- -\b-n\bn Copy at most _\bc_\bo_\bu_\bn_\bt lines. If _\bc_\bo_\bu_\bn_\bt is 0, all lines are
+ 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
+ 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.
+ -\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
+ -\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 line from each line 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
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 as an additional argument. _\bc_\ba_\bl_\bl_\b-
- _\bb_\ba_\bc_\bk is evaluated after the line is read but before the array
- element is assigned.
+ 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_\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, or _\ba_\br_\br_\ba_\by is invalid or unassignable.
+ 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. With no arguments,
- removes the top directory from the stack, and performs a c\bcd\bd to
+ Removes entries from the directory stack. With no arguments,
+ removes the top directory from the stack, and performs a c\bcd\bd to
the new top directory. Arguments, if supplied, have the follow-
ing meanings:
- -\b-n\bn Suppresses the normal change of directory when removing
- directories from the stack, so that only the stack is
+ -\b-n\bn Suppresses the normal change of directory when removing
+ directories from the stack, so that only the stack is
manipulated.
- +\b+_\bn Removes the _\bnth entry counting from the left of the list
- shown by d\bdi\bir\brs\bs, starting with zero. For example: ``popd
+ +\b+_\bn Removes the _\bnth entry counting from the left of the list
+ shown by d\bdi\bir\brs\bs, starting with zero. 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
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 _\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 for-
- mat 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(1) for-
- mats, %\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 (except that \\b\c\bc terminates output,
- backslashes in \\b\'\b', \\b\"\b", and \\b\?\b? are not removed, and octal escapes
- beginning with \\b\0\b0 may contain up to four digits), and %\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.
-
- 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 reused as necessary to consume all of the _\ba_\br_\bg_\bu_\b-
+ 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
+ addition to the standard _\bp_\br_\bi_\bn_\bt_\bf(1) format specifications, p\bpr\bri\bin\bnt\btf\bf
+ interprets the following extensions:
+ %\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%(\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).
+ 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
+ argument 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.
+
+ 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
+ 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,
- the extra format specifications behave as if a zero value or
- null string, as appropriate, had been supplied. The return
+ the extra format specifications behave as if a zero value or
+ null string, as appropriate, had been supplied. The return
value is zero on success, non-zero on failure.
p\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, exchanges the top two directories
- and returns 0, unless the directory stack is empty. Arguments,
- if supplied, have the following meanings:
- -\b-n\bn Suppresses the normal change of directory when 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
+ 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
+ directories and returns 0, unless the directory stack is empty.
+ 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
+ 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
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, making it the
- new current working directory.
+ new current working directory as if it had been supplied
+ as the argument to the c\bcd\bd builtin.
If the p\bpu\bus\bsh\bhd\bd command is successful, a d\bdi\bir\brs\bs is performed as well.
If the first form is used, p\bpu\bus\bsh\bhd\bd returns 0 unless the cd to _\bd_\bi_\br
occurs while reading the name of the current directory or an
invalid option is supplied.
- r\bre\bea\bad\bd [-\b-e\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-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
- descriptor _\bf_\bd supplied as an argument to the -\b-u\bu option, and the
+ r\bre\bea\bad\bd [-\b-e\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
+ descriptor _\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
- second _\bn_\ba_\bm_\be, and so on, with leftover words and their interven-
- ing separators 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 values. The characters in I\bIF\bFS\bS are used to
- split the line into words. 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:
+ 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
+ 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 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
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
- waiting for a complete line of input.
+ 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
+ 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
+ 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
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 is not read within _\bt_\bi_\bm_\be_\bo_\bu_\bt seconds. _\bt_\bi_\bm_\be_\b-
- _\bo_\bu_\bt may be a decimal number with a fractional portion
- following the decimal point. This option is only effec-
- tive 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 _\bt_\bi_\bm_\be_\bo_\bu_\bt is 0, r\bre\bea\bad\bd returns success if
- input is available on the specified file descriptor,
- failure otherwise. The exit status is greater than 128
- if the timeout is exceeded.
+ 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
+ returns immediately, without trying to read any data.
+ The exit status is 0 if input is available on the speci-
+ fied file descriptor, non-zero otherwise. The exit sta-
+ tus 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 is assigned to the vari-
- able R\bRE\bEP\bPL\bLY\bY. The return code is zero, unless end-of-file is
- encountered, r\bre\bea\bad\bd times out (in which case the return code is
- greater than 128), or an invalid file descriptor is supplied as
- the argument to -\b-u\bu.
+ able R\bRE\bEP\bPL\bLY\bY. The exit status is zero, unless end-of-file is
+ encountered, 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
+ readonly variable) occurs, or an invalid file descriptor is sup-
+ plied as the argument to -\b-u\bu.
- r\bre\bea\bad\bdo\bon\bnl\bly\by [-\b-a\baA\bAp\bpf\bf] [_\bn_\ba_\bm_\be[=_\bw_\bo_\br_\bd] ...]
+ 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 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 -\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.
+ arrays. 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 exit with the return value specified by _\bn.
- If _\bn is omitted, the return status is that of the last command
- executed in the function body. If 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 used outside a
- function and not during execution of a script by .\b., the return
- status is false. Any command associated with the R\bRE\bET\bTU\bUR\bRN\bN trap is
- executed before execution resumes after the function or script.
-
- s\bse\bet\bt [-\b--\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] [_\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] [_\ba_\br_\bg ...]
- Without options, the name and value of each shell variable are
+ 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\bet\btu\bur\brn\bn is executed by a trap handler, the last command used to
+ determine 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
+ executed 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
+ significant 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 com-
+ mand associated with the R\bRE\bET\bTU\bUR\bRN\bN trap is executed before execu-
+ tion resumes after the function or script.
+
+ s\bse\bet\bt [-\b--\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] [_\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] [_\ba_\br_\bg ...]
+ Without options, the name and value of each shell variable are
displayed in a format that can be reused as input for setting or
resetting the currently-set variables. Read-only variables can-
- not be reset. In _\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 val-
+ not be reset. In _\bp_\bo_\bs_\bi_\bx mode, only shell variables are listed.
+ The output is sorted according to the current locale. When
+ options are specified, they set or unset shell attributes. Any
+ arguments remaining after option processing are treated as val-
ues for the positional parameters and are assigned, in order, to
- $\b$1\b1, $\b$2\b2, .\b..\b..\b. $\b$_\bn. Options, if specified, have the following
+ $\b$1\b1, $\b$2\b2, .\b..\b..\b. $\b$_\bn. Options, if specified, have the following
meanings:
- -\b-a\ba Automatically mark variables and functions which are
- modified or created for export to the environment of
- subsequent commands.
- -\b-b\bb Report the status of terminated background jobs immedi-
+ -\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.
+ -\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 _\bs_\bu_\bb_\bs_\bh_\be_\bl_\bl command enclosed in
- parentheses, or one of the commands executed as part of
- a command list enclosed by braces (see S\bSH\bHE\bEL\bLL\bL G\bGR\bRA\bAM\bMM\bMA\bAR\bR
- above) 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 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!. A trap on E\bER\bRR\bR,
- if set, is executed before the shell exits. This option
+ -\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 above), 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 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
+ 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
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
+ 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.
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
- support it (see J\bJO\bOB\bB C\bCO\bON\bNT\bTR\bRO\bOL\bL above). Background pro-
- cesses run in a separate process group and a line con-
- taining their exit status is printed upon their comple-
- tion.
+ 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
ignored by interactive shells.
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
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
Same as -\b-E\bE.
f\bfu\bun\bnc\bct\btr\bra\bac\bce\be
Same as -\b-T\bT.
- e\ber\brr\bre\bex\bxi\bit\bt Same as -\b-e\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.
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).
+ 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.
-\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,
- C\bCD\bDP\bPA\bAT\bTH\bH, and G\bGL\bLO\bOB\bBI\bIG\bGN\bNO\bOR\bRE\bE variables, if they appear in the
- environment, are ignored. If the shell is started with
- the effective user (group) id not equal to the real user
- (group) id, and the -\b-p\bp option is not supplied, 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\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
+ appear in the environment, are ignored. If the shell is
+ started with the effective user (group) id not equal to
+ the real user (group) id, and the -\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 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-t\bt Exit after reading and executing one command.
- -\b-u\bu Treat unset variables as an error when performing param-
- eter expansion. If expansion is attempted on an unset
- variable, the shell prints an error message, and, if not
- interactive, exits with a non-zero status.
+ -\b-u\bu Treat unset variables and parameters other than the spe-
+ cial parameters "@" and "*" as an error when performing
+ parameter expansion. If expansion is attempted on an
+ unset variable or parameter, the shell prints an error
+ message, and, if not interactive, exits with a non-zero
+ 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
command, s\bse\bel\ble\bec\bct\bt command, or arithmetic f\bfo\bor\br command, dis-
ited in such cases.
-\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 follow symbolic links when
+ -\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
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 variables controlling optional shell behav-
- ior. With no options, or with the -\b-p\bp option, a list of all set-
- table options is displayed, with an indication of whether or not
- each is set. The -\b-p\bp option causes output to be displayed in a
- form that may be reused as input. Other options have the fol-
- lowing meanings:
+ Toggle the values of settings controlling optional shell behav-
+ 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
+ of all settable options is displayed, with an indication of
+ whether or not each is set. The -\b-p\bp option causes output to be
+ displayed in a form that may be reused as input. Other options
+ 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
-\b-o\bo Restricts the values of _\bo_\bp_\bt_\bn_\ba_\bm_\be to be those defined for
the -\b-o\bo option to the s\bse\bet\bt builtin.
- If either -\b-s\bs or -\b-u\bu is used with no _\bo_\bp_\bt_\bn_\ba_\bm_\be arguments, the dis-
- play is limited to those options which are set or unset, respec-
- tively. Unless otherwise noted, the s\bsh\bho\bop\bpt\bt options are disabled
- (unset) by default.
+ If either -\b-s\bs or -\b-u\bu is used with no _\bo_\bp_\bt_\bn_\ba_\bm_\be arguments, s\bsh\bho\bop\bpt\bt
+ shows only those options which are set or unset, respectively.
+ Unless otherwise noted, the s\bsh\bho\bop\bpt\bt options are disabled (unset)
+ 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
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
- found, the corrected file name is printed, and the com-
+ 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
easy re-editing of multi-line commands.
c\bco\bom\bmp\bpa\bat\bt3\b31\b1
If set, b\bba\bas\bsh\bh changes its behavior to that of version 3.1
- with respect to quoted arguments to the conditional com-
- mand's =~ operator.
+ with respect to quoted arguments to the [\b[[\b[ conditional
+ command's =\b=~\b~ operator and locale-specific string compar-
+ ison when using the [\b[[\b[ conditional command's <\b< and >\b>
+ operators. Bash versions prior to bash-4.1 use ASCII
+ collation and _\bs_\bt_\br_\bc_\bm_\bp(3); bash-4.1 and later use the cur-
+ rent locale's collation sequence and _\bs_\bt_\br_\bc_\bo_\bl_\bl(3).
+ c\bco\bom\bmp\bpa\bat\bt3\b32\b2
+ If set, b\bba\bas\bsh\bh changes its behavior to that of version 3.2
+ with respect to locale-specific string comparison when
+ using the [\b[[\b[ conditional command's <\b< and >\b> operators
+ (see previous item) and the effect of interrupting a
+ command list. Bash versions 3.2 and earlier continue
+ with the next command in the list after one terminates
+ due to an interrupt.
+ c\bco\bom\bmp\bpa\bat\bt4\b40\b0
+ If set, b\bba\bas\bsh\bh changes its behavior to that of version 4.0
+ with respect to locale-specific string comparison when
+ using the [\b[[\b[ conditional command's <\b< and >\b> operators
+ (see description of c\bco\bom\bmp\bpa\bat\bt3\b31\b1) and the effect of inter-
+ rupting a command list. Bash versions 4.0 and later
+ interrupt the list as if the shell received the inter-
+ rupt; previous versions continue with the next command
+ in the list.
+ c\bco\bom\bmp\bpa\bat\bt4\b41\b1
+ If set, b\bba\bas\bsh\bh, when in _\bp_\bo_\bs_\bi_\bx mode, treats a single quote
+ in a double-quoted parameter expansion as a special
+ character. The single quotes must match (an even num-
+ ber) and the characters between the single quotes are
+ considered quoted. This is the behavior of posix mode
+ through version 4.1. The default bash behavior remains
+ as in previous versions.
+ c\bco\bom\bmp\bpa\bat\bt4\b42\b2
+ If set, b\bba\bas\bsh\bh does not process the replacement string in
+ the pattern substitution word expansion using quote
+ removal.
+ c\bco\bom\bmp\bpa\bat\bt4\b43\b3
+ If set, b\bba\bas\bsh\bh does not print a warning message if an
+ attempt is made to use a quoted compound array assign-
+ ment as an argument to d\bde\bec\bcl\bla\bar\bre\be, makes word expansion
+ errors non-fatal errors that cause the current command
+ to fail (the default behavior is to make them fatal
+ errors that cause the shell to exit), and does not reset
+ the loop state when a shell function is executed (this
+ allows b\bbr\bre\bea\bak\bk or c\bco\bon\bnt\bti\bin\bnu\bue\be in a shell function to affect
+ loops in the caller's context).
+ 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 dol-
+ lar sign from the set of characters that will be quoted
+ in completed filenames when these metacharacters appear
+ in shell variable references in words to be completed.
+ This means that dollar signs in variable names that
+ expand to directories will not be quoted; however, any
+ dollar signs appearing in filenames will not be quoted,
+ either. This is active only when bash is using back-
+ slashes to quote completed filenames. This variable is
+ set by default, which is the default bash behavior in
+ 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.
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
+ 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.
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
+ 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 above under
+ If set, aliases are expanded as described above under
A\bAL\bLI\bIA\bAS\bSE\bES\bS. This option is enabled by default for interac-
tive shells.
e\bex\bxt\btd\bde\beb\bbu\bug\bg
- If set, behavior intended for use by debuggers is
+ If set, 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), a call to
- r\bre\bet\btu\bur\brn\bn is simulated.
- 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
+ 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
in their descriptions above.
- 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(
- _\bc_\bo_\bm_\bm_\ba_\bn_\bd )\b) inherit the E\bER\bRR\bRO\bOR\bR trap.
+ 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
above 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
+ 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 above for a
- description of F\bFI\bIG\bGN\bNO\bOR\bRE\bE. This option is enabled by
+ description of F\bFI\bIG\bGN\bNO\bOR\bRE\bE. This option is enabled by
default.
+ 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
+ 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\bst\bta\bar\br
- If set, the pattern *\b**\b* used in a filename expansion con-
- text will match a files and zero or more directories and
- subdirectories. If the pattern is followed by a /\b/, only
- directories and subdirectories match.
+ 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/,
+ only directories and subdirectories match.
g\bgn\bnu\bu_\b_e\ber\brr\brf\bfm\bmt\bt
If set, shell error messages are written in the standard
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
- by the value of the H\bHI\bIS\bST\bTF\bFI\bIL\bLE\bE variable when the shell
+ 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
exits, 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
+ 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
+ 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
+ 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
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
+ 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
commands are saved to the history with embedded newlines
rather than using semicolon separators where possible.
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
fashion when performing matching while executing c\bca\bas\bse\be or
- [\b[[\b[ conditional commands.
+ [\b[[\b[ conditional commands, when performing pattern substi-
+ tution word expansions, or when filtering possible com-
+ pletions as part of programmable completion.
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,
x\bxp\bpg\bg_\b_e\bec\bch\bho\bo
If set, the e\bec\bch\bho\bo builtin expands backslash-escape
sequences by default.
+
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 cannot be suspended; the -\b-f\bf option can be
used to override this and force the suspension. The return sta-
tus is 0 unless the shell is a login shell and -\b-f\bf is not sup-
plied, or if job control is not enabled.
+
t\bte\bes\bst\bt _\be_\bx_\bp_\br
[\b[ _\be_\bx_\bp_\br ]\b]
- Return a status of 0 or 1 depending on the evaluation of the
- conditional expression _\be_\bx_\bp_\br. Each operator and operand 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.
+ 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
+ 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.
+ depends 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
+ 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
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
The expression is parsed and evaluated according to
precedence using the rules listed above.
- t\bti\bim\bme\bes\bs Print the accumulated user and system times for the shell and
+ When used with t\bte\bes\bst\bt or [\b[, the <\b< and >\b> operators sort lexico-
+ graphically using ASCII ordering.
+
+ 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_\br_\bg] _\bs_\bi_\bg_\bs_\bp_\be_\bc ...]
- The command _\ba_\br_\bg is to be read and executed when the shell
- receives signal(s) _\bs_\bi_\bg_\bs_\bp_\be_\bc. If _\ba_\br_\bg 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_\br_\bg 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 invokes.
- If _\ba_\br_\bg is not present and -\b-p\bp has been supplied, then the trap
- commands associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc are displayed. If no
- arguments are supplied or if only -\b-p\bp is given, t\btr\bra\bap\bp prints the
- list of commands associated with each signal. The -\b-l\bl option
- causes the shell to print a list of signal names and their cor-
- responding 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 SIG prefix is optional. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc
- is E\bEX\bXI\bIT\bT (0) the command _\ba_\br_\bg 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_\br_\bg 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, every
- 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
- description of the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the s\bsh\bho\bop\bpt\bt builtin for
- details of its effect on the D\bDE\bEB\bBU\bUG\bG trap. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is E\bER\bRR\bR,
- the command _\ba_\br_\bg is executed whenever a simple command has a
- non-zero exit status, subject to 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, or if the command's return value is being
- inverted via !\b!. These are the same conditions obeyed by the
- e\ber\brr\bre\bex\bxi\bit\bt option. If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is R\bRE\bET\bTU\bUR\bRN\bN, the command _\ba_\br_\bg is exe-
- cuted each time a shell function or a script executed with the .\b.
- or s\bso\bou\bur\brc\bce\be builtins finishes executing. Signals ignored upon
- entry to the shell cannot be trapped or reset. Trapped signals
- that are not being ignored are reset to their original values in
- a child process when it is created. The return status is false
- if any _\bs_\bi_\bg_\bs_\bp_\be_\bc is invalid; otherwise t\btr\bra\bap\bp returns true.
+ The command _\ba_\br_\bg is to be read and executed when the shell
+ receives signal(s) _\bs_\bi_\bg_\bs_\bp_\be_\bc. If _\ba_\br_\bg 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_\br_\bg 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 invokes.
+ If _\ba_\br_\bg is not present and -\b-p\bp has been supplied, then the trap
+ commands associated with each _\bs_\bi_\bg_\bs_\bp_\be_\bc are displayed. If no
+ arguments are supplied or if only -\b-p\bp is given, t\btr\bra\bap\bp prints the
+ list of commands associated with each signal. The -\b-l\bl option
+ causes the shell to print a list of signal names and their cor-
+ responding 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_\br_\bg 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_\br_\bg is exe-
+ cuted 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, every 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 description of the e\bex\bxt\btd\bde\beb\bbu\bug\bg option to the
+ s\bsh\bho\bop\bpt\bt builtin for details 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_\br_\bg is executed each time a shell
+ function or a script executed with the .\b. or s\bso\bou\bur\brc\bce\be builtins fin-
+ ishes executing.
+
+ If a _\bs_\bi_\bg_\bs_\bp_\be_\bc is E\bER\bRR\bR, the command _\ba_\br_\bg 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
+ 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)
+ option.
+
+ Signals ignored upon entry to the shell cannot be trapped or
+ reset. Trapped signals that are not being ignored are reset to
+ their original values in a subshell or subshell environment when
+ one is created. The return status is false if any _\bs_\bi_\bg_\bs_\bp_\be_\bc is
+ invalid; otherwise t\btr\bra\bap\bp returns true.
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
+ 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
- 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 disk file, respectively. If the _\bn_\ba_\bm_\be is not found,
- then nothing is printed, and an exit status of false is
- returned. If the -\b-p\bp option is used, t\bty\byp\bpe\be either returns the
+ 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 disk file, respectively. If the _\bn_\ba_\bm_\be is not found,
+ then nothing is printed, and an exit status of false is
+ returned. If the -\b-p\bp option is used, t\bty\byp\bpe\be either returns the
name of the disk file that would be executed if _\bn_\ba_\bm_\be were speci-
fied as a command name, or nothing if ``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,
+ 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 value, 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 an executable named _\bn_\ba_\bm_\be.
- This includes aliases and functions, if and only if the -\b-p\bp
- option is not also used. The table of hashed commands is not
- consulted when using -\b-a\ba. The -\b-f\bf option suppresses shell func-
- tion 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\bST\bTa\bab\bbc\bcd\bde\bef\bfi\bil\blm\bmn\bnp\bpq\bqr\brs\bst\btu\buv\bvx\bx [_\bl_\bi_\bm_\bi_\bt]]
- Provides control over the resources available to the shell and
- to processes started by it, on systems that allow such control.
+ hashed, -\b-p\bp and -\b-P\bP print the hashed value, which is not necessar-
+ ily 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 an executable
+ named _\bn_\ba_\bm_\be. This includes aliases and functions, if and only if
+ the -\b-p\bp option is not also used. The table of hashed commands is
+ not consulted when using -\b-a\ba. 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\bSa\bab\bbc\bcd\bde\bef\bfi\bik\bkl\blm\bmn\bnp\bpq\bqr\brs\bst\btu\buv\bvx\bxP\bPT\bT [_\bl_\bi_\bm_\bi_\bt]]
+ 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
- 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-
+ 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
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,
- respectively. 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
+ current hard limit, the current soft limit, and no limit,
+ respectively. 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 are printed before the value. Other options are inter-
preted as follows:
-\b-c\bc The maximum size of core files created
-\b-d\bd The maximum size of a process's data segment
-\b-e\be The maximum scheduling priority ("nice")
- -\b-f\bf The maximum size of files written by the shell and its
+ -\b-f\bf The maximum size of files written by the shell and its
children
-\b-i\bi The maximum number of pending signals
+ -\b-k\bk The maximum number of kqueues that may be allocated
-\b-l\bl The maximum size that may be locked into memory
- -\b-m\bm The maximum resident set size (many systems do not honor
+ -\b-m\bm The maximum resident set size (many systems do not honor
this limit)
-\b-n\bn The maximum number of open file descriptors (most systems
do not allow this value to be set)
-\b-r\br The maximum real-time scheduling priority
-\b-s\bs The maximum stack size
-\b-t\bt The maximum amount of cpu time in seconds
- -\b-u\bu The maximum number of processes available to a single
+ -\b-u\bu The maximum number of processes available to a single
user
- -\b-v\bv The maximum amount of virtual memory available to the
- shell
+ -\b-v\bv The maximum amount of virtual memory available to the
+ shell and, on some systems, to its children
-\b-x\bx The maximum number of file locks
+ -\b-P\bP The maximum number of pseudoterminals
-\b-T\bT The maximum number of threads
- If _\bl_\bi_\bm_\bi_\bt is given, it is the new value of the specified resource
- (the -\b-a\ba option is display only). 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-p\bp, which is in units of 512-byte blocks,
- and -\b-T\bT, -\b-b\bb, -\b-n\bn, and -\b-u\bu, which are unscaled values. The return
- status is 0 unless an invalid option or argument is supplied, or
- an error occurs while setting a new limit.
+ 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-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 incre-
+ ments. The return status is 0 unless an invalid option or argu-
+ ment 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
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] [_\bn_\ba_\bm_\be ...]
+ 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 no options are supplied, or the -\b-v\bv option is given, each _\bn_\ba_\bm_\be
- refers to a shell variable. Read-only variables may not be
+ 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. Each unset vari-
- able or function is removed from the environment passed to sub-
- sequent commands. If any of R\bRA\bAN\bND\bDO\bOM\bM, S\bSE\bEC\bCO\bON\bND\bDS\bS, L\bLI\bIN\bNE\bEN\bNO\bO, H\bHI\bIS\bST\bTC\bCM\bMD\bD,
- F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE, G\bGR\bRO\bOU\bUP\bPS\bS, or D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK are unset, they lose their special
- properties, even if they are subsequently reset. The exit sta-
- tus is true unless a _\bn_\ba_\bm_\be is readonly.
-
- w\bwa\bai\bit\bt [_\bn _\b._\b._\b.]
- Wait for each specified process and return its termination sta-
- tus. Each _\bn may be a process ID or a job specification; if a
+ 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, any function with that name is unset. Each
+ unset variable or function is removed from the environment
+ passed to subsequent commands. If any of C\bCO\bOM\bMP\bP_\b_W\bWO\bOR\bRD\bDB\bBR\bRE\bEA\bAK\bKS\bS, R\bRA\bAN\bN-\b-
+ D\bDO\bOM\bM, S\bSE\bEC\bCO\bON\bND\bDS\bS, L\bLI\bIN\bNE\bEN\bNO\bO, H\bHI\bIS\bST\bTC\bCM\bMD\bD, F\bFU\bUN\bNC\bCN\bNA\bAM\bME\bE, G\bGR\bRO\bOU\bUP\bPS\bS, or D\bDI\bIR\bRS\bST\bTA\bAC\bCK\bK 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.
+
+ w\bwa\bai\bit\bt [-\b-n\bn] [_\bn _\b._\b._\b.]
+ Wait for each specified child process and return its termination
+ status. Each _\bn 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 _\bn is not given, all currently active child pro-
- cesses are waited for, and the return status is zero. If _\bn
- specifies a non-existent process or job, the return status is
- 127. Otherwise, the return status is the exit status of the
- last process or job waited for.
+ cesses are waited for, and the return status is zero. If the -\b-n\bn
+ option is supplied, w\bwa\bai\bit\bt waits for any job to terminate and
+ returns its exit status. If _\bn specifies a non-existent process
+ or job, the return status is 127. Otherwise, the return status
+ is the exit status of the last process or job waited for.
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
- behaves 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
+\bo specifying command names containing /\b/
- +\bo specifying a file name containing a /\b/ as an argument to the .\b.
+ +\bo specifying a filename containing a /\b/ as an argument to the .\b.
builtin command
- +\bo Specifying a filename containing a slash as an argument to the
+ +\bo specifying a filename containing a slash as an argument to the
-\b-p\bp option to the h\bha\bas\bsh\bh builtin command
+\bo importing function definitions from the shell environment at
+\bo adding or deleting builtin commands with the -\b-f\bf and -\b-d\bd options
to the e\ben\bna\bab\bbl\ble\be builtin command
- +\bo Using the e\ben\bna\bab\bbl\ble\be builtin command to enable disabled shell
+ +\bo using the e\ben\bna\bab\bbl\ble\be builtin command to enable disabled shell
builtins
+\bo specifying the -\b-p\bp option to the c\bco\bom\bmm\bma\ban\bnd\bd builtin command
_\bT_\bh_\be _\bG_\bn_\bu _\bR_\be_\ba_\bd_\bl_\bi_\bn_\be _\bL_\bi_\bb_\br_\ba_\br_\by, Brian Fox and Chet Ramey
_\bT_\bh_\be _\bG_\bn_\bu _\bH_\bi_\bs_\bt_\bo_\br_\by _\bL_\bi_\bb_\br_\ba_\br_\by, Brian Fox and Chet Ramey
_\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
+ _\bt_\bi_\be_\bs, IEEE --
+ http://pubs.opengroup.org/onlinepubs/9699919799/
+ 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)
_\b~_\b/_\b._\bb_\ba_\bs_\bh_\br_\bc
The individual per-interactive-shell startup file
_\b~_\b/_\b._\bb_\ba_\bs_\bh_\b__\bl_\bo_\bg_\bo_\bu_\bt
- The individual login shell cleanup file, executed when a login
+ The individual login shell cleanup file, executed when a login
shell exits
_\b~_\b/_\b._\bi_\bn_\bp_\bu_\bt_\br_\bc
Individual _\br_\be_\ba_\bd_\bl_\bi_\bn_\be initialization file
B\bBU\bUG\bG R\bRE\bEP\bPO\bOR\bRT\bTS\bS
If you find a bug in b\bba\bas\bsh\bh,\b, 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
- _\bf_\bt_\bp_\b:_\b/_\b/_\bf_\bt_\bp_\b._\bg_\bn_\bu_\b._\bo_\br_\bg_\b/_\bp_\bu_\bb_\b/_\bb_\ba_\bs_\bh_\b/.
-
- 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
- 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
+ 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
+ _\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/.
+
+ 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
+ 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.
ALL bug reports should include:
A description of the bug behaviour
A short script or `recipe' which exercises the bug
- _\bb_\ba_\bs_\bh_\bb_\bu_\bg inserts the first three items automatically into the template
+ _\bb_\ba_\bs_\bh_\bb_\bu_\bg inserts the first three items automatically into the template
it provides for filing a bug report.
Comments and bug reports concerning this manual page should be directed
- to _\bc_\bh_\be_\bt_\b@_\bp_\bo_\b._\bc_\bw_\br_\bu_\b._\be_\bd_\bu.
+ to _\bc_\bh_\be_\bt_\b._\br_\ba_\bm_\be_\by_\b@_\bc_\ba_\bs_\be_\b._\be_\bd_\bu.
B\bBU\bUG\bGS\bS
It's too big and too slow.
Shell builtin commands and functions are not stoppable/restartable.
Compound commands and command sequences of the form `a ; b ; c' are not
- handled gracefully when process suspension is attempted. When a
- process is stopped, the shell immediately executes the next command in
- the sequence. It suffices to place the sequence of commands between
- parentheses to force it into a subshell, which may be stopped as a
+ handled gracefully when process suspension is attempted. When a
+ process is stopped, the shell immediately executes the next command in
+ the sequence. It suffices to place the sequence of commands between
+ parentheses to force it into a subshell, which may be stopped as a
unit.
Array variables may not (yet) be exported.
-GNU Bash-4.0 2009 February 7 BASH(1)
+GNU Bash 4.4 2016 February 8 BASH(1)
projects / thirdparty / bash.git / blobdiff