mirror of
https://https.git.savannah.gnu.org/git/bash.git
synced 2026-06-30 00:49:57 +02:00
commit bash-20120706 snapshot
This commit is contained in:
Chet Ramey
+103
-28
@@ -3,7 +3,7 @@
|
||||
</HEAD>
|
||||
<BODY><TABLE WIDTH=100%>
|
||||
<TR>
|
||||
<TH ALIGN=LEFT width=33%>BASH(1)<TH ALIGN=CENTER width=33%>2012 February 4<TH ALIGN=RIGHT width=33%>BASH(1)
|
||||
<TH ALIGN=LEFT width=33%>BASH(1)<TH ALIGN=CENTER width=33%>2012 July 5<TH ALIGN=RIGHT width=33%>BASH(1)
|
||||
</TR>
|
||||
</TABLE>
|
||||
<BR><A HREF="#index">Index</A>
|
||||
@@ -654,7 +654,7 @@ command:
|
||||
<B>
|
||||
</B>
|
||||
|
||||
! case do done elif else esac fi for function if in select then until while { } time [[ ]]
|
||||
! case coproc do done elif else esac fi for function if in select then until while { } time [[ ]]
|
||||
</DL>
|
||||
|
||||
|
||||
@@ -1202,6 +1202,7 @@ command (see
|
||||
below).
|
||||
The file descriptors can be utilized as arguments to shell 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 <I>NAME</I>_PID.
|
||||
The <B>wait</B>
|
||||
@@ -1592,6 +1593,41 @@ appended to the array beginning at one greater than the array's maximum index
|
||||
associative array.
|
||||
When applied to a string-valued variable, <I>value</I> is expanded and
|
||||
appended to the variable's value.
|
||||
<P>
|
||||
|
||||
A variable can be assigned the <I>nameref</I> attribute using the
|
||||
<B>-n</B> option to the <B>declare</B> or <B>local</B> builtin commands
|
||||
(see the descriptions of <B>declare</B> and <B>local</B> below)
|
||||
to create a <I>nameref</I>, or a reference to another variable.
|
||||
This allows variables to be manipulated indirectly.
|
||||
Whenever the nameref variable is referenced or assigned to, 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
|
||||
<P>
|
||||
<DL COMPACT><DT><DD>
|
||||
<TT>declare -n ref=$1</TT>
|
||||
|
||||
</DL>
|
||||
|
||||
<P>
|
||||
inside the function creates a nameref variable <B>ref</B> whose value is
|
||||
the variable name passed as the first argument.
|
||||
References and assignments to <B>ref</B> are treated as references and
|
||||
assignments to the variable whose name was passed as <B>$1</B>.
|
||||
If the control variable in a <B>for</B> 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 <B>-n</B> attribute.
|
||||
However, nameref variables can reference array variables and subscripted
|
||||
array variables.
|
||||
Namerefs can be unset using the <B>-n</B> option to the <B>unset</B> builtin.
|
||||
Otherwise, if <B>unset</B> is executed with the name of a nameref variable
|
||||
as an argument, the variable referenced by the nameref variable will be unset.
|
||||
<A NAME="lbAU"> </A>
|
||||
<H4>Positional Parameters</H4>
|
||||
|
||||
@@ -2529,7 +2565,7 @@ The name of the file in which command history is saved (see
|
||||
|
||||
</FONT>
|
||||
below). The default value is <A HREF="file:~/.bash_history"><I>~/.bash_history</I></A>. If unset, the
|
||||
command history is not saved when an interactive shell exits.
|
||||
command history is not saved when a shell exits.
|
||||
<DT><B>HISTFILESIZE</B>
|
||||
|
||||
<DD>
|
||||
@@ -2538,7 +2574,7 @@ variable is assigned a value, the history file is truncated, if
|
||||
necessary,
|
||||
to contain no more than that number of lines by removing the oldest entries.
|
||||
The history file is also truncated to this size after
|
||||
writing it when an interactive shell exits.
|
||||
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 <B>HISTSIZE</B>
|
||||
@@ -2958,11 +2994,12 @@ after
|
||||
</FONT>
|
||||
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.
|
||||
number of seconds to wait for a line of input after issuing the
|
||||
primary prompt.
|
||||
<B>Bash</B>
|
||||
|
||||
terminates after waiting for that number of seconds if input does
|
||||
not arrive.
|
||||
terminates after waiting for that number of seconds if a complete
|
||||
line of input does not arrive.
|
||||
<DT><B>TMPDIR</B>
|
||||
|
||||
<DD>
|
||||
@@ -3041,6 +3078,7 @@ be indexed or assigned contiguously.
|
||||
Indexed arrays are referenced using integers (including arithmetic
|
||||
expressions) and are zero-based; associative arrays are referenced
|
||||
using arbitrary strings.
|
||||
Unless otherwise noted, indexed array indices must be non-negative integers.
|
||||
<P>
|
||||
|
||||
An indexed array is created automatically if any variable is assigned to
|
||||
@@ -3451,12 +3489,14 @@ or when
|
||||
|
||||
is followed by a character which is not to be
|
||||
interpreted as part of its name.
|
||||
The <I>parameter</I> is a shell parameter as described above
|
||||
<B>PARAMETERS</B>) or an array reference (<B>Arrays</B>).
|
||||
|
||||
</DL>
|
||||
<P>
|
||||
|
||||
If the first character of <I>parameter</I> is an exclamation point (<B>!</B>),
|
||||
a level of variable indirection is introduced.
|
||||
it introduces a level of variable indirection.
|
||||
<B>Bash</B> uses the value of the variable formed from the rest of
|
||||
<I>parameter</I> as the name of the variable; this variable is then
|
||||
expanded and that value is used in the rest of the substitution, rather
|
||||
@@ -3472,7 +3512,8 @@ In each of the cases below, <I>word</I> is subject to tilde expansion,
|
||||
parameter expansion, command substitution, and arithmetic expansion.
|
||||
<P>
|
||||
|
||||
When not performing substring expansion, using the forms documented below,
|
||||
When not performing substring expansion, using the forms documented below
|
||||
(e.g., <B>:-</B>),
|
||||
<B>bash</B> tests for a parameter that is unset or null. Omitting the colon
|
||||
results in a test only for a parameter that is unset.
|
||||
<P>
|
||||
@@ -3532,33 +3573,50 @@ is substituted.
|
||||
<DT>${<I>parameter</I><B>:</B><I>offset</I><B>:</B><I>length</I>}<DD>
|
||||
|
||||
<B>Substring Expansion</B>.
|
||||
Expands to up to <I>length</I> characters of <I>parameter</I>
|
||||
Expands to up to <I>length</I> characters of the value of <I>parameter</I>
|
||||
starting at the character specified by <I>offset</I>.
|
||||
If <I>length</I> is omitted, expands to the substring of
|
||||
<I>parameter</I> starting at the character specified by <I>offset</I>.
|
||||
If <I>parameter</I> is <B>@</B>, an indexed array subscripted by
|
||||
<B>@</B> or <B>*</B>, or an associative array name, the results differ as
|
||||
described below.
|
||||
If <I>length</I> is omitted, expands to the substring of the value of
|
||||
<I>parameter</I> starting at the character specified by <I>offset</I>
|
||||
and extending to the end of the value.
|
||||
<I>length</I> and <I>offset</I> are arithmetic expressions (see
|
||||
<FONT SIZE=-1><B>ARITHMETIC EVALUATION</B>
|
||||
|
||||
</FONT>
|
||||
below).
|
||||
<P>
|
||||
If <I>offset</I> evaluates to a number less than zero, the value
|
||||
is used as an offset from the end of the value of <I>parameter</I>.
|
||||
If <I>length</I> evaluates to a number less than zero, and <I>parameter</I>
|
||||
is not <B>@</B> and not an indexed or associative array, it is interpreted
|
||||
as an offset from the end of the value of <I>parameter</I> rather than
|
||||
a number of characters, and the expansion is the characters between the
|
||||
two offsets.
|
||||
is used as an offset in characters
|
||||
from the end of the value of <I>parameter</I>.
|
||||
If <I>length</I> evaluates to a number less than zero,
|
||||
it is interpreted as an offset in characters
|
||||
from the end of the value of <I>parameter</I> rather than
|
||||
a number of characters, and the expansion is the characters between
|
||||
<I>offset</I> and that result.
|
||||
Note that a negative offset must be separated from the colon by at least
|
||||
one space to avoid being confused with the <B>:-</B> expansion.
|
||||
<P>
|
||||
If <I>parameter</I> is <B>@</B>, the result is <I>length</I> positional
|
||||
parameters beginning at <I>offset</I>.
|
||||
A negative <I>offset</I> 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 expansion error if <I>length</I> evaluates to a number less than
|
||||
zero.
|
||||
<P>
|
||||
If <I>parameter</I> is an indexed array name subscripted by @ or *,
|
||||
the result is the <I>length</I>
|
||||
members of the array beginning with ${<I>parameter</I>[<I>offset</I>]}.
|
||||
A negative <I>offset</I> is taken relative to one greater than the maximum
|
||||
index of the specified array.
|
||||
It is an expansion error if <I>length</I> evaluates to a number less than
|
||||
zero.
|
||||
<P>
|
||||
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.
|
||||
<P>
|
||||
Substring indexing is zero-based unless the positional parameters
|
||||
are used, in which case the indexing starts at 1 by default.
|
||||
If <I>offset</I> is 0, and the positional parameters are used, <B>$0</B> is
|
||||
@@ -4421,13 +4479,13 @@ File descriptor 2 is duplicated.
|
||||
<DD>
|
||||
If <I>host</I> is a valid hostname or Internet address, and <I>port</I>
|
||||
is an integer port number or service name, <B>bash</B> attempts to open
|
||||
a TCP connection to the corresponding socket.
|
||||
the corresponding TCP socket.
|
||||
<DT><B>/dev/udp/</B><I>host</I>/<I>port</I>
|
||||
|
||||
<DD>
|
||||
If <I>host</I> is a valid hostname or Internet address, and <I>port</I>
|
||||
is an integer port number or service name, <B>bash</B> attempts to open
|
||||
a UDP connection to the corresponding socket.
|
||||
the corresponding UDP socket.
|
||||
|
||||
</DL></DL>
|
||||
|
||||
@@ -8100,7 +8158,7 @@ These timestamps are optionally displayed depending on the value of the
|
||||
|
||||
</FONT>
|
||||
variable.
|
||||
When an interactive shell exits, the last
|
||||
When a shell with history enabled exits, the last
|
||||
<FONT SIZE=-1><B>$HISTSIZE</B>
|
||||
|
||||
</FONT>
|
||||
@@ -9301,9 +9359,9 @@ must be >= 1. If
|
||||
is greater than the number of enclosing loops, the last enclosing loop
|
||||
(the ``top-level'' loop) is resumed.
|
||||
The return value is 0 unless <I>n</I> is not greater than or equal to 1.
|
||||
<DT><B>declare</B> [<B>-aAfFgilrtux</B>] [<B>-p</B>] [<I>name</I>[=<I>value</I>] ...]<DD>
|
||||
<DT><B>declare</B> [<B>-aAfFgilnrtux</B>] [<B>-p</B>] [<I>name</I>[=<I>value</I>] ...]<DD>
|
||||
|
||||
<DT><B>typeset</B> [<B>-aAfFgilrtux</B>] [<B>-p</B>] [<I>name</I>[=<I>value</I>] ...]<DD>
|
||||
<DT><B>typeset</B> [<B>-aAfFgilnrtux</B>] [<B>-p</B>] [<I>name</I>[=<I>value</I>] ...]<DD>
|
||||
|
||||
Declare variables and/or give them attributes.
|
||||
If no <I>name</I>s are given then display the values of variables.
|
||||
@@ -9383,6 +9441,16 @@ above) is performed when the variable is assigned a value.
|
||||
When the variable is assigned a value, all upper-case characters are
|
||||
converted to lower-case.
|
||||
The upper-case attribute is disabled.
|
||||
<DT><B>-n</B>
|
||||
|
||||
<DD>
|
||||
Give each <I>name</I> the <I>nameref</I> attribute, making
|
||||
it a name reference to another variable.
|
||||
That other variable is defined by the value of <I>name</I>.
|
||||
All references and assignments to <I>name</I>, except for changing the
|
||||
<B>-n</B> attribute itself, are performed on the variable referenced by
|
||||
<I>name</I>'s value.
|
||||
The <B>-n</B> attribute cannot be applied to array variables.
|
||||
<DT><B>-r</B>
|
||||
|
||||
<DD>
|
||||
@@ -12570,7 +12638,7 @@ value is true unless a supplied
|
||||
<I>name</I>
|
||||
|
||||
is not a defined alias.
|
||||
<DT><B>unset</B> [-<B>fv</B>] [<I>name</I> ...]<DD>
|
||||
<DT><B>unset</B> [-<B>fv</B>] [-<B>n</B>] [<I>name</I> ...]<DD>
|
||||
For each
|
||||
<I>name</I>,
|
||||
|
||||
@@ -12591,6 +12659,13 @@ is specified, each
|
||||
|
||||
refers to a shell function, and the function definition
|
||||
is removed.
|
||||
If the
|
||||
<B>-n</B>
|
||||
|
||||
option is supplied, and <I>name</I> is a variable with the <I>nameref</I>
|
||||
attribute, <I>name</I> will be unset rather than the variable it
|
||||
references.
|
||||
<B>-n</B> has no effect if the <B>-f</B> option is supplied.
|
||||
If no options are supplied, each <I>name</I> refers to a variable; if
|
||||
there is no variable by that name, any function with that name is
|
||||
unset.
|
||||
@@ -12930,7 +13005,7 @@ There may be only one active coprocess at a time.
|
||||
<HR>
|
||||
<TABLE WIDTH=100%>
|
||||
<TR>
|
||||
<TH ALIGN=LEFT width=33%>GNU Bash 4.2<TH ALIGN=CENTER width=33%>2012 February 4<TH ALIGN=RIGHT width=33%>BASH(1)
|
||||
<TH ALIGN=LEFT width=33%>GNU Bash 4.2<TH ALIGN=CENTER width=33%>2012 July 5<TH ALIGN=RIGHT width=33%>BASH(1)
|
||||
</TR>
|
||||
</TABLE>
|
||||
<HR>
|
||||
@@ -13036,6 +13111,6 @@ There may be only one active coprocess at a time.
|
||||
</DL>
|
||||
<HR>
|
||||
This document was created by man2html from bash.1.<BR>
|
||||
Time: 05 March 2012 21:31:01 EST
|
||||
Time: 05 July 2012 20:43:10 EDT
|
||||
</BODY>
|
||||
</HTML>
|
||||
|
||||
Reference in New Issue
Block a user