.\" Case Western Reserve University
.\" chet.ramey@case.edu
.\"
-.\" Last Change: Thu Dec 14 11:05:39 EST 2023
+.\" Last Change: Thu Jan 18 11:41:18 EST 2024
.\"
.\" bash_builtins, strip all but Built-Ins section
.\" avoid a warning about an undefined register
.\" .if !rzY .nr zY 0
.if \n(zZ=1 .ig zZ
.if \n(zY=1 .ig zY
-.TH BASH 1 "2023 December 14" "GNU Bash 5.3"
+.TH BASH 1 "2024 January 18" "GNU Bash 5.3"
.\"
.\" There's some problem with having a `@'
.\" in a tagged paragraph with the BSD man macros.
.\"
.\" File Name macro. This used to be `.PN', for Path Name,
.\" but Sun doesn't seem to like that very much.
+.\" The \% is to prevent the filename from hyphenation.
.\"
.de FN
-\fI\|\\$1\|\fP
+\%\fI\|\\$1\|\fP
+..
+.\"
+.\" Quotation macro: generate consistent quoted strings that don't rely
+.\" on the presence of the `CW' constant-width font.
+.\"
+.de Q
+.ie \n(.g \(lq\\$1\(rq\\$2
+.el \{
+. if t ``\\$1''\\$2
+. if n "\\$1"\\$2
+.\}
+..
+.de QN
+.ie \n(.g \%\(lq\\$1\(rq\\$2
+.el \{
+. if t \%``\%\\$1''\\$2
+. if n \%"\%\\$1"\\$2
+.\}
..
.SH NAME
bash \- GNU Bourne-Again SHell
expanded value as the name of a file to read and execute.
.B Bash
behaves as if the following command were executed:
-.sp .5
+.PP
.RS
-.if t \f(CWif [ \-n "$BASH_ENV" ]; then . "$BASH_ENV"; fi\fP
-.if n if [ \-n "$BASH_ENV" ]; then . "$BASH_ENV"; fi
+.EX
+if [ \-n "$BASH_ENV" ]; then . "$BASH_ENV"; fi
+.EE
.RE
-.sp .5
+.PP
but the value of the
.SM
.B PATH
and are removed.
.TP
\fB[[\fP \fIexpression\fP \fB]]\fP
+.PD
Return a status of 0 or 1 depending on the evaluation of
the conditional expression \fIexpression\fP.
Expressions are composed of the primaries described below under
(the expansions that would occur if the words were enclosed in double quotes).
Conditional operators such as \fB\-f\fP must be unquoted to be recognized
as primaries.
-.if t .sp 0.5
-.if n .sp 1
+.IP
When used with \fB[[\fP, the \fB<\fP and \fB>\fP operators sort
lexicographically using the current locale.
-.if t .sp 0.5
-.if n .sp 1
+.IP
When the \fB==\fP and \fB!=\fP operators are used, the string to the
right of the operator is considered a pattern and matched according
to the rules described below under \fBPattern Matching\fP,
(\fB!=\fP) the pattern, and 1 otherwise.
Any part of the pattern may be quoted to force the quoted portion
to be matched as a string.
-.if t .sp 0.5
-.if n .sp 1
+.IP
An additional binary operator, \fB=\(ti\fP, is available, with the same
precedence as \fB==\fP and \fB!=\fP.
When it is used, the string to the right of the operator is considered
a POSIX extended regular expression and matched accordingly
(using the POSIX \fIregcomp\fP and \fIregexec\fP interfaces
-usually described in \fIregex\fP(3)).
+usually described in
+.IR regex (3)).
The return value is 0 if the string matches
the pattern, and 1 otherwise.
If the regular expression is syntactically incorrect, the conditional
Treat bracket expressions in regular expressions carefully,
since normal quoting and pattern characters lose their meanings
between brackets.
-.if t .sp 0.5
-.if n .sp 1
+.IP
The pattern will match if it matches any part of the string.
Anchor the pattern using the \fB\(ha\fP and \fB$\fP regular expression
operators to force it to match the entire string.
.B BASH_REMATCH
in the global scope; declaring it as a local variable will lead to
unexpected results.
-.if t .sp 0.5
-.if n .sp 1
+.IP
Expressions may be combined using the following operators, listed
in decreasing order of precedence:
-.if t .sp 0.5
-.if n .sp 1
+.IP
.RS
.PD 0
.TP
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
-.sp .5
+.PP
.RS
-.if t \f(CWdeclare \-n ref=$1\fP
-.if n declare \-n ref=$1
+.EX
+declare \-n ref=$1
+.EE
.RE
-.sp .5
+.PP
inside the function creates a nameref variable \fBref\fP whose value is
the variable name passed as the first argument.
References and assignments to \fBref\fP, and changes to its attributes,
When the
expansion occurs within double quotes, each parameter expands to a
separate word. That is, "\fB$@\fP" is equivalent to
-"\fB$1\fP" "\fB$2\fP" ...
+"\fB$1\fP"\ "\fB$2\fP"\ ...
If the double-quoted expansion occurs within a word, the expansion of
the first parameter is joined with the beginning part of the original
word, and the expansion of the last parameter is joined with the last
this instance of
.BR bash .
The values assigned to the array members are as follows:
-.sp .5
+.PP
.RS
.TP 24
.B BASH_VERSINFO[\fR0\fP]
The build version.
.TP
.B BASH_VERSINFO[\fR4\fP]
-The release status (e.g., \fIbeta1\fP).
+The release status (e.g., \fIbeta\fP).
.TP
.B BASH_VERSINFO[\fR5\fP]
The value of
.TP
.B EPOCHREALTIME
Each time this parameter is referenced, it expands to the number of seconds
-since the Unix Epoch (see \fItime\fP\fR(3)\fP) as a floating point value
-with micro-second granularity.
+since the Unix Epoch (see
+.IR time (3))
+as a floating point value with micro-second granularity.
Assignments to
.SM
.B EPOCHREALTIME
.TP
.B EPOCHSECONDS
Each time this parameter is referenced, it expands to the number of seconds
-since the Unix Epoch (see \fItime\fP\fR(3)\fP).
+since the Unix Epoch (see
+.IR time (3)).
Assignments to
.SM
.B EPOCHSECONDS
shell startup. This variable is readonly.
.TP
.B FUNCNAME
+.PD
An array variable containing the names of all shell functions
currently in the execution call stack.
The element with index 0 is the name of any currently-executing
shell function.
The bottom-most element (the one with the highest index) is
-.if t \f(CW"main"\fP.
-.if n "main".
+.Q main .
This variable exists only when a shell function is executing.
Assignments to
.SM
.B FUNCNAME
is unset, it loses its special properties, even if it is
subsequently reset.
-.if t .sp 0.5
-.if n .sp 1
+.IP
This variable can be used with \fBBASH_LINENO\fP and \fBBASH_SOURCE\fP.
Each element of \fBFUNCNAME\fP has corresponding elements in
\fBBASH_LINENO\fP and \fBBASH_SOURCE\fP to describe the call stack.
\fB${BASH_LINENO[\fP\fI$i\fP\fB]}\fP.
The \fBcaller\fP builtin displays the current call stack using this
information.
+.PD 0
.TP
.B GROUPS
An array variable containing the list of groups of which the current
.TP
.B READLINE_ARGUMENT
Any numeric argument given to a readline command that was defined using
-.if t \f(CWbind \-x\fP
-.if n "bind \-x"
+.Q "bind \-x"
(see
.SM
.B "SHELL BUILTIN COMMANDS"
The contents of the
.B readline
line buffer, for use with
-.if t \f(CWbind \-x\fP
-.if n "bind \-x"
+.Q "bind \-x"
(see
.SM
.B "SHELL BUILTIN COMMANDS"
The position of the mark (saved insertion point) in the
.B readline
line buffer, for use with
-.if t \f(CWbind \-x\fP
-.if n "bind \-x"
+.Q "bind \-x"
(see
.SM
.B "SHELL BUILTIN COMMANDS"
The position of the insertion point in the
.B readline
line buffer, for use with
-.if t \f(CWbind \-x\fP
-.if n "bind \-x"
+.Q "bind \-x"
(see
.SM
.B "SHELL BUILTIN COMMANDS"
.B SRANDOM
This variable expands to a 32-bit pseudo-random number each time it is
referenced. The random number generator is not linear on systems that
-support \f(CW/dev/urandom\fP or \fIarc4random\fP, so each returned number
+support
+.FN /dev/urandom
+or
+.IR arc4random (3),
+so each returned number
has no relationship to the numbers preceding it.
The random number generator cannot be seeded, so assignments to this
variable have no effect.
If \fBBASH_COMPAT\fP is set to a value that is not one of the valid
compatibility levels, the shell prints an error message and sets the
compatibility level to the default for the current version.
-The valid values correspond to the compatibility levels
+A subset of the valid values correspond to the compatibility levels
described below under
.SM
.BR "SHELL COMPATIBILITY MODE" .
.B BASH_XTRACEFD
If set to an integer corresponding to a valid file descriptor, \fBbash\fP
will write the trace output generated when
-.if t \f(CWset \-x\fP
-.if n \fIset \-x\fP
+.Q "set \-x"
is enabled to that file descriptor.
The file descriptor is closed when
.SM
.B cd
command.
A sample value is
-.if t \f(CW".:\(ti:/usr"\fP.
-.if n ".:\(ti:/usr".
+.Q .:\(ti:/usr .
.TP
.B CHILD_MAX
Set the number of exited child status values for the shell to remember.
.B EMACS
If \fBbash\fP finds this variable in the environment when the shell starts
with value
-.if t \f(CWt\fP,
-.if n "t",
+.Q "t" ,
it assumes that the shell is running in an Emacs shell buffer and disables
line editing.
.TP
.B FIGNORE
is excluded from the list of matched filenames.
A sample value is
-.if t \f(CW".o:\(ti"\fP.
-.if n ".o:\(ti".
+.Q ".o:\(ti" .
.TP
.B FUNCNEST
If set to a numeric value greater than 0, defines a maximum function
.TP
.B HISTTIMEFORMAT
If this variable is set and not null, its value is used as a format string
-for \fIstrftime\fP(3) to print the time stamp associated with each history
+for
+.IR strftime (3)
+to print the time stamp associated with each history
entry displayed by the \fBhistory\fP builtin.
If this variable is set, time stamps are written to the history file so
they may be preserved across shell sessions.
split lines into words with the
.B read
builtin command. The default value is
-``<space><tab><newline>''.
+.Q <space><tab><newline> .
.TP
.B IGNOREEOF
Controls the
.BR bash .
A common value is
.na
-.if t \f(CW/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin\fP.
-.if n ``/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin''.
+.Q /usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin .
.ad
.TP
.B POSIXLY_CORRECT
.B \-\-posix
invocation option had been supplied. If it is set while the shell is
running, \fBbash\fP enables \fIposix mode\fP, as if the command
-.if t \f(CWset -o posix\fP
-.if n \fIset -o posix\fP
+.Q "set \-o posix"
had been executed.
When the shell enters \fIposix mode\fP, it sets this variable if it was
not already set.
.SM
.B PROMPTING
below) and used as the primary prompt string. The default value is
-``\fB\es\-\ev\e$ \fP''.
+.Q "\es\-\ev\e$\ " .
.TP
.B PS2
The value of this parameter is expanded as with
.SM
.B PS1
and used as the secondary prompt string. The default is
-``\fB> \fP''.
+.Q ">\ " .
.TP
.B PS3
The value of this parameter is used as the prompt for the
.B PS1
and the value is printed before each command
.B bash
-displays during an execution trace. The first character of
-the expanded value of
+displays during an execution trace.
+The first character of the expanded value of
.SM
.B PS4
is replicated multiple times, as necessary, to indicate multiple
-levels of indirection. The default is ``\fB+ \fP''.
+levels of indirection.
+The default is
+.Q "+\ " .
.TP
.B SHELL
This variable expands to the full pathname to the shell.
The \fB%\fP character introduces an escape sequence that is
expanded to a time value or other information.
The escape sequences and their meanings are as follows; the
-braces denote optional portions.
-.sp .5
+brackets denote optional portions.
+.PP
.RS
.PD 0
.TP 10
.B
ARITHMETIC EVALUATION
below).
-.sp 1
+.IP
If \fIoffset\fP evaluates to a number less than zero, the value
is used as an offset in characters
from the end of the value of \fIparameter\fP.
\fIoffset\fP 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 \fB:-\fP expansion.
-.sp 1
+.IP
If \fIparameter\fP is \fB@\fP or \fB*\fP, the result is \fIlength\fP
positional parameters beginning at \fIoffset\fP.
A negative \fIoffset\fP is taken relative to one greater than the greatest
parameter (or 0 if there are no positional parameters).
It is an expansion error if \fIlength\fP evaluates to a number less than
zero.
-.sp 1
+.IP
If \fIparameter\fP is an indexed array name subscripted by @ or *,
the result is the \fIlength\fP
members of the array beginning with ${\fIparameter\fP[\fIoffset\fP]}.
index of the specified array.
It is an expansion error if \fIlength\fP evaluates to a number less than
zero.
-.sp 1
+.IP
Substring expansion applied to an associative array produces undefined
results.
-.sp 1
+.IP
Substring indexing is zero-based unless the positional parameters
are used, in which case the indexing starts at 1 by default.
If \fIoffset\fP is 0, and the positional parameters are used, \fB$0\fP is
.IR parameter ,
then the result of the expansion is the expanded value of
.I parameter
-with the shortest matching pattern (the ``\fB#\fP'' case) or the
-longest matching pattern (the ``\fB##\fP'' case) deleted.
+with the shortest matching pattern (the
+.Q #
+case) or the longest matching pattern (the
+.Q ##
+case) deleted.
If
.I parameter
is
.IR parameter ,
then the result of the expansion is the expanded value of
.I parameter
-with the shortest matching pattern (the ``\fB%\fP'' case) or the
-longest matching pattern (the ``\fB%%\fP'' case) deleted.
+with the shortest matching pattern (the
+.Q %
+case) or the longest matching pattern (the
+.Q %%
+case) deleted.
If
.I parameter
is
If \fIstring\fP is null,
matches of \fIpattern\fP are deleted
and the \fB/\fP following \fIpattern\fP may be omitted.
-.sp 1
+.IP
If the \fBpatsub_replacement\fP shell option is enabled using \fBshopt\fP,
any unquoted instances of \fB&\fP in \fIstring\fP are replaced with the
matching portion of \fIpattern\fP.
-.sp 1
+.IP
Quoting any part of \fIstring\fP inhibits replacement in the
expansion of the quoted portion, including replacement strings stored
in shell variables.
shell programmers should quote any occurrences of \fB&\fP
they want to be taken literally in the replacement
and ensure any instances of \fB&\fP they want to be replaced are unquoted.
-.sp 1
+.IP
If the
.B nocasematch
shell option is enabled, the match is performed without regard to the case
The expansion is either a transformation of the value of \fIparameter\fP
or information about \fIparameter\fP itself, depending on the value of
\fIoperator\fP. Each \fIoperator\fP is a single letter:
-.sp 1
+.PP
.RS
.PD 0
.TP
.BR * ,
the operation is applied to each member of the
array in turn, and the expansion is the resultant list.
-.sp 1
+.PP
The result of the expansion is subject to word splitting and pathname
expansion as described below.
.RE
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
-\f(CW\-d\(aq\^\(aq\fP becomes \f(CW\-d\fP after word splitting and
-null argument removal.
+.Q "\-d\(aq\^\(aq"
+becomes
+.Q \-d
+after word splitting and null argument removal.
.PP
Note that if no expansion occurs, no splitting
is performed.
of alphabetic characters.
When a pattern is used for pathname expansion,
the character
-.B ``.''
+.Q .\&
at the start of a name or immediately following a slash
must be matched explicitly, unless the shell option
.B dotglob
is set.
In order to match the filenames
-.B ``.''
+.Q .\&
and
-.BR ``..'' ,
-the pattern must begin with ``.'' (for example, ``.?''),
+.Q ..\& ,
+the pattern must begin with
+.Q .\&
+(for example,
+.Q .?\& ),
even if
.B dotglob
is set.
If the
.B globskipdots
shell option is enabled, the filenames
-.B ``.''
+.Q .\&
and
-.BR ``..''
-are never matched, even if the pattern begins with a
-.BR ``.'' .
+.Q ..\&
+never match, even if the pattern begins with a
+.Q .\&
When not matching pathnames, the
-.B ``.''
+.Q .\&
character is not treated specially.
When matching a pathname, the slash character must always be
matched explicitly by a slash in the pattern, but in other matching
.B GLOBIGNORE
is performed without regard to case.
The filenames
-.B ``.''
+.Q .\&
and
-.B ``..''
+.Q ..\&
are always ignored when
.SM
.B GLOBIGNORE
-is set and not null. However, setting
+is set and not null.
+However, setting
.SM
.B GLOBIGNORE
to a non-null value has the effect of enabling the
.B dotglob
shell option, so all other filenames beginning with a
-.B ``.''
+Q .\&
will match.
To get the old behavior of ignoring filenames beginning with a
-.BR ``.'' ,
+.Q .\& ,
make
-.B ``.*''
+.Q .*
one of the patterns in
.SM
.BR GLOBIGNORE .
\fBPattern Matching\fP
.PP
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.
+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.
.PP
Matches any single character.
.TP
.B [...]
-Matches any one of the enclosed characters. A pair of characters
-separated by a hyphen denotes a
+Matches any one of the enclosed characters.
+A pair of characters separated by a hyphen denotes a
\fIrange expression\fP;
any character that falls between those two characters, inclusive,
using the current locale's collating sequence and character set,
.B ]
may be matched by including it as the first character
in the set.
-.if t .sp 0.5
-.if n .sp 1
+.PD
+.IP
Within
.B [
and
\fIcharacter classes\fP can be specified using the syntax
\fB[:\fP\fIclass\fP\fB:]\fP, where \fIclass\fP is one of the
following classes defined in the POSIX standard:
-.PP
+.IP
.RS
.B
.if n alnum alpha ascii blank cntrl digit graph lower print punct space \
upper word xdigit
.if t alnum alpha ascii blank cntrl digit graph lower \
print punct space upper word xdigit
-.br
+.RE
+.IP
A character class matches any character belonging to that class.
The \fBword\fP character class matches letters, digits, and the character _.
-.if t .sp 0.5
-.if n .sp 1
+.IP
Within
.B [
and
\fB[=\fP\fIc\fP\fB=]\fP, which matches all characters with the
same collation weight (as defined by the current locale) as
the character \fIc\fP.
-.if t .sp 0.5
-.if n .sp 1
+.IP
Within
.B [
and
the syntax \fB[.\fP\fIsymbol\fP\fB.]\fP matches the collating symbol
\fIsymbol\fP.
.RE
-.RE
-.PD
.PP
If the \fBextglob\fP shell option is enabled using the \fBshopt\fP
builtin, the shell recognizes several extended pattern matching operators.
or more patterns separated by a \fB|\fP.
Composite patterns may be formed using one or more of the following
sub-patterns:
-.sp 1
+.PP
.PD 0
.RS
.TP
When matching filenames, the \fBdotglob\fP shell option determines
the set of filenames that are tested:
when \fBdotglob\fP is enabled, the set of filenames includes all files
-beginning with ``.'', but ``.'' and ``..'' must be matched by a
-pattern or sub-pattern that begins with a dot;
+beginning with
+.Q .\& ,
+but
+.Q .\&
+and
+.Q ..\&
+must be matched by a pattern or sub-pattern that begins with a dot;
when it is disabled, the set does not
-include any filenames beginning with ``.'' unless the pattern
-or sub-pattern begins with a ``.''.
-As above, ``.'' only has a special meaning when matching filenames.
+include any filenames beginning with
+.Q .\&
+unless the pattern or sub-pattern begins with a
+.Q .\& .
+As above,
+.Q .\&
+only has a special meaning when matching filenames.
.PP
Complicated extended pattern matching against long strings is slow,
especially when the patterns contain alternations and the strings
In the following description, the \fIcurrent scope\fP is a currently-
executing function.
Previous scopes consist of that function's caller and so on,
-back to the "global" scope, where the shell is not executing
-any shell function.
+back to the
+.Q global
+scope, where the shell is not executing any shell function.
Consequently, a local variable at the current scope is a variable
declared using the \fBlocal\fP or \fBdeclare\fP builtins in the
function that is currently executing.
.PP
-Local variables "shadow" variables with the same name declared at
+Local variables
+.Q shadow
+variables with the same name declared at
previous scopes.
For instance, a local variable declared in a function
hides a global variable of the same name: references and assignments
to reach the current function.
The value of a variable that a function sees depends
on its value within its caller, if any, whether that caller is
-the "global" scope or another shell function.
+the global
+scope or another shell function.
This is also the value that a local variable
-declaration "shadows", and the value that is restored when the function
-returns.
+declaration shadows,
+and the value that is restored when the function returns.
.PP
For example, if a variable \fIvar\fP is declared as local in function
\fIfunc1\fP, and \fIfunc1\fP calls another function \fIfunc2\fP,
.PP
Unless otherwise specified, primaries that operate on files follow symbolic
links and operate on the target of the link, rather than the link itself.
-.if t .sp 0.5
-.if n .sp 1
+.PP
When used with \fB[[\fP,
or when the shell is in \fIposix mode\fP,
the \fB<\fP and \fB>\fP operators sort
lexicographically using the current locale.
When the shell is not in \fIposix mode\fP,
the \fBtest\fP command sorts using ASCII ordering.
-.sp 1
+.PP
.PD 0
.TP
.B \-a \fIfile\fP
True if \fIfile\fP exists and is a symbolic link.
.TP
.B \-k \fIfile\fP
-True if \fIfile\fP exists and its ``sticky'' bit is set.
+True if \fIfile\fP exists and its
+.Q sticky
+bit is set.
.TP
.B \-p \fIfile\fP
True if \fIfile\fP exists and is a named pipe (FIFO).
is invoked in a separate execution environment that consists of
the following.
Unless otherwise noted, the values are inherited from the shell.
-.if n .sp 1
.IP \(bu
the shell's open files, plus any modifications and additions specified
by redirections to the command
subshell environment. Changes made to the subshell environment
cannot affect the shell's execution environment.
.PP
-Subshells spawned to execute command substitutions inherit the value of
-the \fB\-e\fP option from the parent shell. When not in \fIposix mode\fP,
+When the shell is in
+\fIposix mode\fP,
+subshells spawned to execute command substitutions inherit the value of
+the \fB\-e\fP option from their parent shell.
+When not in \fIposix mode\fP,
\fBbash\fP clears the \fB\-e\fP option in such subshells.
+See the
+description of the \fBinherit_errexit\fP shell option below
+for how to control this behavior when not in posix mode.
.PP
If a command is followed by a \fB&\fP and job control is not active, the
default standard input for the command is the empty file \fI/dev/null\fP.
processes are those whose process group ID differs from the terminal's;
such processes are immune to keyboard-generated signals.
Only foreground processes are allowed to read from or, if the
-user so specifies with \f(CWstty tostop\fP, write to the
-terminal.
+user so specifies with
+.Q "stty tostop" ,
+write to the terminal.
Background processes which attempt to read from (write to when
-\f(CWstty tostop\fP is in effect) the
-terminal are sent a
+.Q "tostop"
+is in effect) the terminal are sent a
.SM
.B SIGTTIN (SIGTTOU)
signal by the kernel's terminal driver,
foreground:
.B %1
is a synonym for
-\fB``fg %1''\fP,
+.Q "fg %1" ,
bringing job 1 from the background into the foreground.
Similarly,
-.B ``%1 &''
+.Q "%1 &"
resumes job 1 in the background, equivalent to
-\fB``bg %1''\fP.
+.Q "bg %1" .
.PP
The shell learns immediately whenever a job changes state.
Normally,
an ASCII bell character (07)
.TP
.B \ed
-the date in "Weekday Month Date" format (e.g., "Tue May 26")
+the date in
+.Q "Weekday Month Date"
+format (e.g.,
+.Q "Tue May 26" )
.TP
.B \eD{\fIformat\fP}
-the \fIformat\fP is passed to \fIstrftime\fP(3) and the result is inserted
+the \fIformat\fP is passed to
+.IR strftime (3)
+and the result is inserted
into the prompt string; an empty \fIformat\fP results in a locale-specific
time representation. The braces are required
.TP
.RS
C\-Meta\-u: universal\-argument
.RE
+.LP
into the
.I inputrc
would make M\-C\-u execute the readline command
When using the form \fBkeyname\fP:\^\fIfunction\-name\fP or \fImacro\fP,
.I keyname
is the name of a key spelled out in English. For example:
-.sp
+.PP
.RS
Control-u: universal\-argument
.br
.I C\-o
is bound to run the macro
expressed on the right hand side (that is, to insert the text
-.if t \f(CW> output\fP
-.if n ``> output''
+.Q "> output"
into the line).
.PP
In the second form, \fB"keyseq"\fP:\^\fIfunction\-name\fP or \fImacro\fP,
within double quotes. Some GNU Emacs style key escapes can be
used, as in the following example, but the symbolic character names
are not recognized.
-.sp
+.PP
.RS
"\eC\-u": universal\-argument
.br
and
.I "ESC [ 1 1 \(ti"
is bound to insert the text
-.if t \f(CWFunction Key 1\fP.
-.if n ``Function Key 1''.
+.Q "Function Key 1" .
.PP
The full set of GNU Emacs style escape sequences is
.RS
This variable is reset to the default value whenever the terminal type changes.
The default value is the string that puts the terminal in standout mode,
as obtained from the terminal's terminfo description.
-A sample value might be \f(CW"\ee[01;33m"\fP.
+A sample value might be
+.Q "\ee[01;33m" .
.TP
.B active\-region\-end\-color
-A string variable that "undoes" the effects of \fBactive\-region\-start\-color\fP
-and restores "normal" terminal display appearance after displaying text
-in the active region.
+A string variable that
+.Q undoes
+the effects of \fBactive\-region\-start\-color\fP
+and restores
+.Q normal
+terminal display appearance after displaying text in the active region.
This string must not take up any physical character positions on the display,
so it should consist only of terminal escape sequences.
It is output to the terminal after displaying the text in the active region.
This variable is reset to the default value whenever the terminal type changes.
The default value is the string that restores the terminal from standout mode,
as obtained from the terminal's terminfo description.
-A sample value might be \f(CW"\ee[0m"\fP.
+A sample value might be
+.Q "\ee[0m" .
.TP
.B bell\-style (audible)
Controls what happens when readline wants to ring the terminal bell.
treated specially by the kernel's terminal driver to their
readline equivalents.
These override the default readline bindings described here.
-Type \f(CWstty -a\fP at a bash prompt to see your current terminal settings,
+Type
+.Q "stty \-a"
+at a \fBbash\fP prompt to see your current terminal settings,
including the special control characters (usually \fBcchars\fP).
.TP
.B blink\-matching\-paren (Off)
The color definitions are taken from the value of the \fBLS_COLORS\fP
environment variable.
If there is a color definition in \fB$LS_COLORS\fP for the custom suffix
-"readline-colored-completion-prefix", readline uses this color for
+.Q readline-colored-completion-prefix ,
+readline uses this color for
the common prefix instead of its default.
.TP
.B colored\-stats (Off)
This could be used to bind key sequences to functions useful for
a specific program. For instance, the following command adds a
key sequence that quotes the current or previous word in \fBbash\fP:
-.sp 1
+.PP
.RS
.nf
\fB$if\fP Bash
This directive takes a single filename as an argument and reads commands
and bindings from that file. For example, the following directive
would read \fI/etc/inputrc\fP:
-.sp 1
+.PP
.RS
.nf
\fB$include\fP \^ \fI/etc/inputrc\fP
.PP
Readline remembers the last incremental search string. If two
Control-Rs are typed without any intervening characters defining a
-new search string, any remembered search string is used.
+new search string, readline uses any remembered search string.
.PP
Non-incremental searches read the entire search string before starting
to search for matching history lines. The search string may be
in the previous command begin with word 0). A negative argument
inserts the \fIn\fPth word from the end of the previous command.
Once the argument \fIn\fP is computed, the argument is extracted
-as if the "!\fIn\fP" history expansion had been specified.
+as if the
+.Q !\fIn\fP
+history expansion had been specified.
.TP
.B
yank\-last\-arg (M\-.\^, M\-_\^)
the direction to move through the history. A negative argument switches
the direction through the history (back or forward).
The history expansion facilities are used to extract the last word,
-as if the "!$" history expansion had been specified.
+as if the
+.Q !$
+history expansion had been specified.
.TP
.B shell\-expand\-line (M\-C\-e)
Expand the line by performing shell word expansions.
.TP
.B \fIend\-of\-file\fP (usually C\-d)
The character indicating end-of-file as set, for example, by
-.if t \f(CWstty\fP.
-.if n ``stty''.
+.IR stty (1).
If this character is read when there are no characters
on the line, and point is at the beginning of the line, readline
interprets it as the end of input and returns
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 "\e[", keys producing such sequences will have no effect
+bound to
+.Q \e[ ,
+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\-[.
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:
-.PP
-\f(CW_completion_loader()
-.br
+.RS
+.EX
+.nf
+_completion_loader()
{
+ . "/etc/bash_completion.d/$1.sh" \c
+.if \n(LL<80n \{\
+\e
.br
- . "/etc/bash_completion.d/$1.sh" >/dev/null 2>&1 && return 124
-.br
+.ti +4n
+.\}
+>/dev/null 2>&1 && return 124
}
+complete \-D \-F _completion_loader \c
+.if \n(LL<80n \{\
+\e
.br
-complete \-D \-F _completion_loader -o bashdefault -o default
-.br
-\fP
+.ti +4n
+.\}
+\-o bashdefault \-o default
+.fi
+.EE
+.RE
.SH HISTORY
When the
.B \-o history
with
.IR string2 .
Equivalent to
-``!!:s\d\s+2\(ha\s-2\u\fIstring1\fP\d\s+2\(ha\s-2\u\fIstring2\fP\d\s+2\(ha\s-2\u''
+.Q !!:s\d\s+2\(ha\s-2\u\fIstring1\fP\d\s+2\(ha\s-2\u\fIstring2\fP\d\s+2\(ha\s-2\u
(see \fBModifiers\fP below).
.TP
.B !#
Other builtins that accept arguments but are not specified as accepting
options interpret arguments beginning with \fB\-\fP as invalid options and
require \fB\-\-\fP to prevent this interpretation.
-.sp .5
+.PP
.PD 0
.TP
\fB:\fP [\fIarguments\fP]
.B CDPATH
defines the search path for the directory containing
.IR dir :
-each directory name in
+the shell searches each directory name in
.SM
.B CDPATH
-is searched for \fIdir\fP.
+for \fIdir\fP.
Alternative directory names in
.SM
.B CDPATH
are separated by a colon (:). A null directory name in
.SM
.B CDPATH
-is the same as the current directory, i.e., ``\fB.\fP''. If
+is the same as the current directory, i.e.,
+.Q .\& .
+If
.I dir
begins with a slash (/),
then
When using the \fB\-F\fP or \fB\-C\fP options, the various shell variables
set by the programmable completion facilities, while available, will not
have useful values.
-.sp 1
+.IP
The matches will be generated in the same way as if the programmable
completion code had generated them directly from a completion specification
with the same flags.
If \fIword\fP is specified, only those completions matching \fIword\fP
will be displayed.
-.sp 1
+.IP
The return value is true unless an invalid option is supplied, or no
matches were generated.
.TP
each \fIname\fP, or, if no \fIname\fPs are supplied, all
completion specifications.
The \fB\-D\fP option indicates that other supplied options and actions should
-apply to the ``default'' command completion; that is, completion attempted
+apply to the
+.Q default
+command completion; that is, completion attempted
on a command for which no completion has previously been defined.
The \fB\-E\fP option indicates that other supplied options and actions should
-apply to ``empty'' command completion; that is, completion attempted on a
+apply to
+.Q empty
+command completion; that is, completion attempted on a
blank line.
The \fB\-I\fP option indicates that other supplied options and actions should
apply to completion on the initial non-assignment word on the line, or after
If any of \fB\-D\fP, \fB\-E\fP, or \fB\-I\fP are supplied, any other
\fIname\fP arguments are ignored; these completions only apply to the case
specified by the option.
-.sp 1
+.IP
The process of applying these completion specifications when word completion
is attempted is described
-.ie \n(zZ=1 in \fIbash(1)\fP.
+.ie \n(zZ=1 in \fIbash\fP(1).
.el above under \fBProgrammable Completion\fP.
-.sp 1
+.IP
Other options, if specified, have the following meanings.
The arguments to the \fB\-G\fP, \fB\-W\fP, and \fB\-X\fP options
(and, if necessary, the \fB\-P\fP and \fB\-S\fP options)
should be quoted to protect them from expansion before the
.B complete
builtin is invoked.
-.sp 1
+.IP
.RS
.PD 0
.TP 8
The possible values of \fIoption\fP are those valid for the \fBcomplete\fP
builtin described above.
The \fB\-D\fP option indicates that other supplied options should
-apply to the ``default'' command completion; that is, completion attempted
+apply to the
+.Q default
+command completion; that is, completion attempted
on a command for which no completion has previously been defined.
The \fB\-E\fP option indicates that other supplied options should
-apply to ``empty'' command completion; that is, completion attempted on a
-blank line.
+apply to
+.Q empty
+command completion; that is, completion attempted on a blank line.
The \fB\-I\fP option indicates that other supplied options should
apply to completion on the initial non-assignment word on the line,
or after a command delimiter such as \fB;\fP or \fB|\fP, which is usually
command name completion.
-.sp 1
+.IP
The return value is true unless an invalid option is supplied, an attempt
is made to modify the options for a \fIname\fP for which no completion
specification exists, or an output error occurs.
.I n
must be \(>= 1. If
.I n
-is greater than the number of enclosing loops, the last enclosing loop
-(the ``top-level'' loop) is resumed.
+is greater than the number of enclosing loops, the shell resumes
+the last enclosing loop
+(the
+.Q top-level
+loop).
The return value is 0 unless \fIn\fP is not greater than or equal to 1.
.TP
\fBdeclare\fP [\fB\-aAfFgiIlnrtux\fP] [\fB\-p\fP] [\fIname\fP[=\fIvalue\fP] ...]
.B \-a
Each \fIname\fP is an indexed array variable (see
.B Arrays
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
.TP
.B \-A
Each \fIname\fP is an associative array variable (see
.B Arrays
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
.TP
.B \-f
The variable is treated as an integer; arithmetic evaluation (see
.SM
.B "ARITHMETIC EVALUATION"
-.ie \n(zZ=1 in \fIbash(1)\fP)
+.ie \n(zZ=1 in \fIbash\fP(1))
.el above)
is performed when the variable is assigned a value.
.TP
subsequent assignments.
The return value is 0 unless an invalid option is encountered,
an attempt is made to define a function using
-.if n ``\-f foo=bar'',
-.if t \f(CW\-f foo=bar\fP,
+.Q "\-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
.B Arrays
-.ie \n(zZ=1 in \fIbash(1)\fP),
+.ie \n(zZ=1 in \fIbash\fP(1)),
.el above),
one of the \fInames\fP is not a valid shell variable name,
an attempt is made to turn off readonly status for a readonly variable,
.SM
.B PATH
instead of the shell builtin version, run
-.if t \f(CWenable \-n test\fP.
-.if n ``enable \-n test''.
+.QN "enable \-n test" .
The
.B \-f
option means to load the new builtin command
colon-separated list of directories in which to search for \fIfilename\fP,
if \fIfilename\fP does not contain a slash.
The default is system-dependent,
-and may include "." to force a search of the current directory.
+and may include
+.Q .\&
+to force a search of the current directory.
The
.B \-d
option will delete a builtin previously loaded with
If no options are supplied and a \fIname\fP is not a shell builtin,
\fBenable\fP will attempt to load \fIname\fP from a shared object named
\fIname\fP, as if the command were
-.if t \f(CWenable \-f\fP \fIname name\fP .
-.if n ``enable \-f \fIname name\fP .
+.QN "enable \-f \fIname name\fP" .
The return value is 0 unless a
.I name
is not a shell builtin or there is an error loading a new builtin
.I last
is not specified, it is set to
the current command for listing (so that
-.if n ``fc \-l \-10''
-.if t \f(CWfc \-l \-10\fP
+.QN "fc \-l \-10"
prints the last 10 commands) and to
.I first
otherwise.
.I first
is not specified, it is set to the previous
command for editing and \-16 for listing.
-.sp 1
+.IP
The
.B \-n
option suppresses
.FN vi
is used. When editing is complete, the edited commands are
echoed and executed.
-.sp 1
+.IP
In the second form, \fIcommand\fP is re-executed after each instance
of \fIpat\fP is replaced by \fIrep\fP.
\fICommand\fP is interpreted the same as \fIfirst\fP above.
A useful alias to use with this is
-.if n ``r="fc \-s"'',
-.if t \f(CWr='fc \-s'\fP,
+.Q "r=""fc \-s""" ,
so that typing
-.if n ``r cc''
-.if t \f(CWr cc\fP
+.Q "r cc"
runs the last command beginning with
-.if n ``cc''
-.if t \f(CWcc\fP
+.Q cc
and typing
-.if n ``r''
-.if t \f(CWr\fP
+.Q r
re-executes the last command.
-.sp 1
+.IP
If the first form is used, the return value is 0 unless an invalid
option is encountered or
.I first
.B getopts
within the same shell invocation if a new set of parameters
is to be used.
-.sp 1
+.IP
When the end of options is encountered, \fBgetopts\fP exits with a
return value greater than zero.
.SM
.B OPTIND
is set to the index of the first non-option argument,
and \fIname\fP is set to ?.
-.sp 1
+.IP
.B getopts
normally parses the positional parameters, but if more arguments are
supplied as
values,
.B getopts
parses those instead.
-.sp 1
+.IP
.B getopts
can report errors in two ways. If the first character of
.I optstring
character of
.I optstring
is not a colon.
-.sp 1
-If an invalid option is seen,
+.IP
+If
.B getopts
-places ? into
+detects an invalid option, it places ? into
.I name
and, if not silent,
prints an error message and unsets
.BR OPTARG .
If
.B getopts
-is silent,
-the option character found is placed in
+is silent, it assigns the option character found to
.SM
.B OPTARG
-and no diagnostic message is printed.
-.sp 1
+and does not print a diagnostic message.
+.IP
If a required argument is not found, and
.B getopts
-is not silent,
-a question mark (\^\fB?\fP\^) is placed in
-.IR name ,
+is not silent, it sets the value of \fIname\fP to
+a question mark (\^\fB?\fP\^), unsets
.SM
-.B OPTARG
-is unset, and a diagnostic message is printed.
+.BR OPTARG ,
+and prints a diagnostic message.
If
.B getopts
-is silent, then a colon (\^\fB:\fP\^) is placed in
-.I name
-and
+is silent, it sets the value of \fIname\fP to a colon (\^\fB:\fP\^)
+and sets
.SM
.B OPTARG
-is set to the option character found.
-.sp 1
+to the option character found.
+.IP
.B getopts
returns true if an option, specified or unspecified, is found.
It returns false if the end of options is encountered or an
.B \-s
Display only a short usage synopsis for each \fIpattern\fP
.PD
-.PP
+.RE
+.IP
The return status is 0 unless no command matches
.IR pattern .
-.RE
.TP
\fBhistory [\fIn\fP]
.PD 0
.SM
.B HISTTIMEFORMAT
is set and not null,
-it is used as a format string for \fIstrftime\fP(3) to display
-the time stamp associated with each displayed history entry.
+it is used as a format string for
+.IR strftime (3)
+to display the time stamp associated with each displayed history entry.
No intervening blank is printed between the formatted time stamp
and the history line.
If \fIfilename\fP is supplied, it is used as the
are interpreted as described above.
.TP
.B \-a
-Append the ``new'' history lines to the history file.
+Append the
+.Q new
+history lines to the history file.
These are history lines entered since the beginning of the current
\fBbash\fP session, but not already appended to the history file.
.TP
is an arithmetic expression to be evaluated (see
.SM
.B "ARITHMETIC EVALUATION"
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
If the last
.I arg
.BR dirs ,
starting with zero, from the stack.
For example:
-.if n ``popd +0''
-.if t \f(CWpopd +0\fP
+.Q "popd +0"
removes the first directory,
-.if n ``popd +1''
-.if t \f(CWpopd +1\fP
+.Q "popd +1"
the second.
.TP
\fB\-\fP\fIn\fP
shown by
.BR dirs ,
starting with zero. For example:
-.if n ``popd \-0''
-.if t \f(CWpopd \-0\fP
+.Q "popd \-0"
removes the last directory,
-.if n ``popd \-1''
-.if t \f(CWpopd \-1\fP
+.Q "popd \-1"
the next to last.
.PD
.PP
control of the \fIformat\fP.
The \fB\-v\fP option causes the output to be assigned to the variable
\fIvar\fP rather than being printed to the standard output.
-.sp 1
+.IP
The \fIformat\fP 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
\fIargument\fP.
-In addition to the standard \fIprintf\fP(3) format characters
+In addition to the standard
+.IR printf (3)
+format characters
.BR csndiouxXeEfFgGaA ,
\fBprintf\fP interprets the following additional format specifiers:
.RS
.TP
.B %(\fIdatefmt\fP)T
causes \fBprintf\fP to output the date-time string resulting from using
-\fIdatefmt\fP as a format string for \fIstrftime\fP(3).
+\fIdatefmt\fP as a format string for
+.IR strftime (3).
The corresponding \fIargument\fP is an integer representing the number of
seconds since the epoch.
Two special argument values may be used: \-1 represents the current
One line is read from the standard input, or from the file descriptor
\fIfd\fP supplied as an argument to the \fB\-u\fP option,
split into words as described
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP (1)
.el above
under \fBWord Splitting\fP,
and the first word
.B IFS
are used to split the line into words using the same rules the shell
uses for expansion (described
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP (1)
.el above
under \fBWord Splitting\fP).
The backslash character (\fB\e\fP) may be used to remove any special
(see
.SM
.B READLINE
-.ie \n(zZ=1 in \fIbash(1)\fP)
+.ie \n(zZ=1 in \fIbash\fP(1))
.el above)
to obtain the line.
Readline uses the current (or default, if line editing was not previously
(see
.SM
.B READLINE
-.ie \n(zZ=1 in \fIbash(1)\fP)
+.ie \n(zZ=1 in \fIbash\fP(1))
.el above)
to obtain the line.
Readline uses the current (or default, if line editing was not previously
Read input from file descriptor \fIfd\fP.
.PD
.PP
+Other than the case where \fIdelim\fP is the empty string, \fBread\fP
+ignores any NUL characters in the input.
+.PP
If no
.I names
are supplied, the line read,
.TP
\fBset \-o\fP
.TP
-\fBset \+o\fP
+\fBset +o\fP
.PD
Without options, display the name and value of each shell variable
in a format that can be reused as input
effective only when job control is enabled.
.TP 8
.B \-e
+.PD
Exit immediately if a
\fIpipeline\fP (which may consist of a single \fIsimple command\fP),
a \fIlist\fP,
(see
.SM
.B SHELL GRAMMAR
-.ie \n(zZ=1 in \fIbash(1)\fP),
+.ie \n(zZ=1 in \fIbash\fP(1)),
.el above),
exits with a non-zero status.
The shell does not exit if the
separately (see
.SM
.B "COMMAND EXECUTION ENVIRONMENT"
-.ie \n(zZ=1 in \fIbash(1)\fP),
+.ie \n(zZ=1 in \fIbash\fP(1)),
.el above),
and may cause
subshells to exit before executing all the commands in the subshell.
-.if t .sp 0.5
-.if n .sp 1
+.IP
If a compound command or shell function executes in a context
where \fB\-e\fP is being ignored,
none of the commands executed within the compound command or function body
a context where \fB\-e\fP is ignored, that setting will not have any
effect until the compound command or the command containing the function
call completes.
+.PD 0
.TP 8
.B \-f
Disable pathname expansion.
it (see
.SM
.B JOB CONTROL
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
All processes run in a separate process group.
When a background job completes, the shell prints a line
.TP 8
.B history
Enable command history, as described
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
under
.SM
.TP 8
.B ignoreeof
The effect is as if the shell command
-.if t \f(CWIGNOREEOF=10\fP
-.if n ``IGNOREEOF=10''
+.QN "IGNOREEOF=10"
had been executed
(see
.B Shell Variables
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
.TP 8
.B keyword
See
.SM
.B "SEE ALSO"
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el below
for a reference to a document that details how posix mode affects
bash's behavior.
.B xtrace
Same as
.BR \-x .
-.sp .5
.PP
If
.B \-o
.B \-B
The shell performs brace expansion (see
.B Brace Expansion
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
This is on by default.
.TP 8
option.
.PP
The list of \fBshopt\fP options is:
-.if t .sp .5v
-.if n .sp 1v
+.PP
.PD 0
.TP 8
.B array_expand_once
intervening command (see
.SM
.B "JOB CONTROL"
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
The shell always postpones exiting if any jobs are stopped.
.TP 8
easy re-editing of multi-line commands.
This option is enabled by default, but only has an effect if command
history is enabled, as described
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
under
.SM
(see
.SM
.B "SHELL COMPATIBILITY MODE"
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el below).
.TP 8
.B complete_fullquote
.B dotglob
If set,
.B bash
-includes filenames beginning with a `.' in the results of pathname
-expansion.
+includes filenames beginning with a
+.Q .\&
+in the results of pathname expansion.
The filenames
-.B ``.''
+.Q .\&
and
-.B ``..''
+.Q ..\&
must always be matched explicitly, even if
.B dotglob
is set.
.TP 8
.B expand_aliases
If set, aliases are expanded as described
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
under
.SM
.SM
.B BASH_ARGV
are updated as described in their descriptions
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
.TP
.B 5.
.TP 8
.B extglob
If set, the extended pattern matching features described
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
under
\fBPathname Expansion\fP are enabled.
See
.SM
\fBSHELL VARIABLES\fP
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
for a description of
.SM
If set, range expressions used in pattern matching bracket expressions (see
.SM
.B Pattern Matching
-.ie \n(zZ=1 in \fIbash(1)\fP)
+.ie \n(zZ=1 in \fIbash\fP(1))
.el above)
behave as if in the traditional C locale when performing
comparisons. That is, the current locale's collating sequence
.TP 8
.B globskipdots
If set, pathname expansion will never match the filenames
-.B ``.''
+.Q .\&
and
-.BR ``..'' ,
+.Q ..\& ,
even if the pattern begins with a
-.BR ``.'' .
+.Q .\& .
This option is enabled by default.
.TP 8
.B globstar
under
.SM
.B READLINE
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
This is enabled by default.
.TP 8
line to be ignored in an interactive shell (see
.SM
.B COMMENTS
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
This option is enabled by default.
.TP 8
The shell sets this option if it is started as a login shell (see
.SM
.B "INVOCATION"
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
The value may not be changed.
.TP 8
.B mailwarn
If set, and a file that \fBbash\fP is checking for mail has been
-accessed since the last time it was checked, the message ``The mail in
-\fImailfile\fP has been read'' is displayed.
+accessed since the last time it was checked,
+\fBbash\fP displays the message
+.Q "The mail in \fImailfile\fP has been read" .
.TP 8
.B no_empty_cmd_completion
If set, and
matches filenames in a case\-insensitive fashion when performing pathname
expansion (see
.B Pathname Expansion
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
.TP 8
.B nocasematch
If set, pathname expansion patterns which match no files
(see
.B Pathname Expansion
-.ie \n(zZ=1 in \fIbash(1)\fP)
+.ie \n(zZ=1 in \fIbash\fP(1))
.el above)
expand to nothing and are removed,
rather than expanding to themselves.
expands occurrences of \fB&\fP in the replacement string of pattern
substitution to the text matched by the pattern, as described
under \fBParameter Expansion\fP
-.ie \n(zZ=1 in \fIbash(1)\fP.
+.ie \n(zZ=1 in \fIbash\fP(1).
.el above.
This option is enabled by default.
.TP 8
.B progcomp
If set, the programmable completion facilities (see
\fBProgrammable Completion\fP
-.ie \n(zZ=1 in \fIbash(1)\fP)
+.ie \n(zZ=1 in \fIbash\fP(1))
.el above)
are enabled.
This option is enabled by default.
expansion, and quote removal after being expanded as described in
.SM
.B PROMPTING
-.ie \n(zZ=1 in \fIbash(1)\fP.
+.ie \n(zZ=1 in \fIbash\fP(1).
.el above.
This option is enabled by default.
.TP 8
(see
.SM
.B "RESTRICTED SHELL"
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el below).
The value may not be changed.
This is not reset when the startup files are executed, allowing
\fI{varname}\fP redirection syntax (see
.SM
.B REDIRECTION
-.ie \n(zZ=1 in \fIbash(1)\fP)
+.ie \n(zZ=1 in \fIbash\fP(1))
.el above)
instead of leaving them open when the command completes.
.TP 8
.PD 0
.TP
\fB[\fP \fIexpr\fP \fB]\fP
+.PD
Return a status of 0 (true) or 1 (false) depending on
the evaluation of the conditional expression
.IR expr .
Each operator and operand must be a separate argument.
Expressions are composed of the primaries described
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
under
.SM
.BR "CONDITIONAL EXPRESSIONS" .
\fBtest\fP does not accept any options, nor does it accept and ignore
an argument of \fB\-\-\fP as signifying the end of options.
-.if t .sp 0.5
-.if n .sp 1
+.IP
Expressions may be combined using the following operators, listed
in decreasing order of precedence.
The evaluation depends on the number of arguments; see below.
.PP
\fBtest\fP and \fB[\fP evaluate conditional
expressions using a set of rules based on the number of arguments.
-.if t .sp 0.5
-.if n .sp 1
+.PP
.PD 0
.TP
0 arguments
If the first argument is \fB!\fP, the expression is true if and
only if the second argument is null.
If the first argument is one of the unary conditional operators listed
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
under
.SM
3 arguments
The following conditions are applied in the order listed.
If the second argument is one of the binary conditional operators listed
-.ie \n(zZ=1 in \fIbash(1)\fP
+.ie \n(zZ=1 in \fIbash\fP(1)
.el above
under
.SM
5 or more arguments
The expression is parsed and evaluated according to precedence
using the rules listed above.
-.if t .sp 0.5
-.if n .sp 1
-.LP
+.PD
+.PP
If the shell is not in \fIposix mode\fP,
when used with \fBtest\fP or \fB[\fP, the \fB<\fP and \fB>\fP operators
sort lexicographically using ASCII ordering.
When the shell is in \fIposix mode\fP, these operators sort using the
current locale.
.RE
-.PD
.TP
.B times
Print the accumulated user and system times for the shell and
is the null string the signal specified by each
.I sigspec
is ignored by the shell and by the commands it invokes.
-.if t .sp 0.5
-.if n .sp 1
+.IP
If no arguments are supplied,
.B trap
displays the actions associated with each trapped signal
in a subshell environment (e.g., command substitution) and, as
long as they are used before \fBtrap\fP is used to change a signal's
handling, will display the state of its parent's traps.
-.if t .sp 0.5
-.if n .sp 1
+.IP
The
.B \-l
option causes \fBtrap\fP to print a list of signal names and
.SM
.B SIG
prefix is optional.
-.if t .sp 0.5
-.if n .sp 1
+.IP
If a
.I sigspec
is
in a shell function (see
.SM
.B SHELL GRAMMAR
-.ie \n(zZ=1 in \fIbash(1)\fP).
+.ie \n(zZ=1 in \fIbash\fP(1)).
.el above).
Refer to the description of the \fBextdebug\fP option to the
\fBshopt\fP builtin for details of its effect on the \fBDEBUG\fP trap.
.I action
is executed each time a shell function or a script executed with
the \fB.\fP or \fBsource\fP builtins finishes executing.
-.if t .sp 0.5
-.if n .sp 1
+.IP
If a
.I sigspec
is
being inverted using
.BR ! .
These are the same conditions obeyed by the \fBerrexit\fP (\fB\-e\fP) option.
-.if t .sp 0.5
-.if n .sp 1
+.IP
When the shell is not interactive,
signals ignored upon entry to the shell cannot be trapped or reset.
Interactive shells permit trapping signals ignored on entry.
.I name
were specified as a command name,
or nothing if
-.if t \f(CWtype \-t name\fP
-.if n ``type \-t name''
+.Q "type \-t name"
would not return
.IR file .
The
.SM
.B PATH
search for each \fIname\fP, even if
-.if t \f(CWtype \-t name\fP
-.if n ``type \-t name''
+.Q "type \-t name"
would not return
.IR file .
If a command is hashed,
The maximum size of a process's data segment
.TP
.B \-e
-The maximum scheduling priority ("nice")
+The maximum scheduling priority (
+.Q nice ).
.TP
.B \-f
The maximum size of files written by the shell and its children
If \fBwait\fP is interrupted by a signal, the return status will be greater
than 128, as described under
.B SIGNALS
-.ie \n(zZ=1 in \fIbash(1)\fP.
+.ie \n(zZ=1 in \fIbash\fP(1).
.el above.
Otherwise, the return status is the exit status of the last
process or job waited for.
arithmetic expressions used as indexed array subscripts can be
expanded more than once
.IP \(bu
-\fBtest \-v\fP, when given an argument of \fBA[@]\fP, where \fBA\P is
+\fBtest \-v\fP, when given an argument of \fBA[@]\fP, where \fBA\fP is
an existing associative array, will return true if the array has any set
elements.
Bash-5.2 will look for and report on a key named \fB@\fP.
projects / thirdparty / bash.git / commitdiff
