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commit bash-20170324 snapshot

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Chet Ramey
2017-03-28 11:32:59 -04:00
parent f698849a75
commit 124d67cde0
41 changed files with 9975 additions and 9249 deletions
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@@ -9,7 +9,7 @@ SSYYNNOOPPSSIISS
bbaasshh [options] [command_string | file]
CCOOPPYYRRIIGGHHTT
Bash is Copyright (C) 1989-2016 by the Free Software Foundation, Inc.
Bash is Copyright (C) 1989-2017 by the Free Software Foundation, Inc.
DDEESSCCRRIIPPTTIIOONN
BBaasshh is an sshh-compatible command language interpreter that executes
@@ -22,9 +22,9 @@ DDEESSCCRRIIPPTTIIOONN
OOPPTTIIOONNSS
All of the single-character shell options documented in the description
of the sseett builtin command can be used as options when the shell is
invoked. In addition, bbaasshh interprets the following options when it is
invoked:
of the sseett builtin command, including --oo, can be used as options when
the shell is invoked. In addition, bbaasshh interprets the following
options when it is invoked:
--cc If the --cc option is present, then commands are read from the
first non-option argument _c_o_m_m_a_n_d___s_t_r_i_n_g. If there are argu-
@@ -1286,9 +1286,9 @@ PPAARRAAMMEETTEERRSS
command (see SSHHEELLLL GGRRAAMMMMAARR above).
PPSS44 The value of this parameter is expanded as with PPSS11 and the
value is printed before each command bbaasshh displays during an
execution trace. The first character of PPSS44 is replicated mul-
tiple times, as necessary, to indicate multiple levels of indi-
rection. The default is ``++ ''.
execution trace. The first character of the expanded value of
PPSS44 is replicated multiple times, as necessary, to indicate mul-
tiple levels of indirection. The default is ``++ ''.
SSHHEELLLL The full pathname to the shell is kept in this environment vari-
able. If it is not set when the shell starts, bbaasshh assigns to
it the full pathname of the current user's login shell.
@@ -2176,12 +2176,11 @@ RREEDDIIRREECCTTIIOONN
[_n]<<<<<<_w_o_r_d
The _w_o_r_d 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 _n if
_n is specified).
The _w_o_r_d undergoes tilde expansion, parameter and variable expansion,
command substitution, arithmetic expansion, and quote removal. Path-
name expansion and word splitting are not performed. The result is
supplied as a single string, with a newline appended, to the command on
its standard input (or file descriptor _n if _n is specified).
DDuupplliiccaattiinngg FFiillee DDeessccrriippttoorrss
The redirection operator
@@ -2189,22 +2188,22 @@ RREEDDIIRREECCTTIIOONN
[_n]<<&&_w_o_r_d
is used to duplicate input file descriptors. If _w_o_r_d expands to one or
more digits, the file descriptor denoted by _n is made to be a copy of
that file descriptor. If the digits in _w_o_r_d do not specify a file
descriptor open for input, a redirection error occurs. If _w_o_r_d evalu-
ates to --, file descriptor _n is closed. If _n is not specified, the
more digits, the file descriptor denoted by _n is made to be a copy of
that file descriptor. If the digits in _w_o_r_d do not specify a file
descriptor open for input, a redirection error occurs. If _w_o_r_d evalu-
ates to --, file descriptor _n is closed. If _n is not specified, the
standard input (file descriptor 0) is used.
The operator
[_n]>>&&_w_o_r_d
is used similarly to duplicate output file descriptors. If _n is not
specified, the standard output (file descriptor 1) is used. If the
digits in _w_o_r_d do not specify a file descriptor open for output, a re-
direction error occurs. If _w_o_r_d evaluates to --, file descriptor _n is
closed. As a special case, if _n is omitted, and _w_o_r_d does not expand
to one or more digits or --, the standard output and standard error are
is used similarly to duplicate output file descriptors. If _n is not
specified, the standard output (file descriptor 1) is used. If the
digits in _w_o_r_d do not specify a file descriptor open for output, a re-
direction error occurs. If _w_o_r_d evaluates to --, file descriptor _n is
closed. As a special case, if _n is omitted, and _w_o_r_d does not expand
to one or more digits or --, the standard output and standard error are
redirected as described previously.
MMoovviinngg FFiillee DDeessccrriippttoorrss
@@ -2212,7 +2211,7 @@ RREEDDIIRREECCTTIIOONN
[_n]<<&&_d_i_g_i_t--
moves the file descriptor _d_i_g_i_t to file descriptor _n, or the standard
moves the file descriptor _d_i_g_i_t to file descriptor _n, or the standard
input (file descriptor 0) if _n is not specified. _d_i_g_i_t is closed after
being duplicated to _n.
@@ -2220,7 +2219,7 @@ RREEDDIIRREECCTTIIOONN
[_n]>>&&_d_i_g_i_t--
moves the file descriptor _d_i_g_i_t to file descriptor _n, or the standard
moves the file descriptor _d_i_g_i_t to file descriptor _n, or the standard
output (file descriptor 1) if _n is not specified.
OOppeenniinngg FFiillee DDeessccrriippttoorrss ffoorr RReeaaddiinngg aanndd WWrriittiinngg
@@ -2228,81 +2227,102 @@ RREEDDIIRREECCTTIIOONN
[_n]<<>>_w_o_r_d
causes the file whose name is the expansion of _w_o_r_d to be opened for
both reading and writing on file descriptor _n, or on file descriptor 0
causes the file whose name is the expansion of _w_o_r_d to be opened for
both reading and writing on file descriptor _n, or on file descriptor 0
if _n is not specified. If the file does not exist, it is created.
AALLIIAASSEESS
_A_l_i_a_s_e_s 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 aalliiaass and uunnaalliiaass builtin
commands (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS 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 //,
$$, ``, and == and any of the shell _m_e_t_a_c_h_a_r_a_c_t_e_r_s or quoting characters
_A_l_i_a_s_e_s allow a string to be substituted for a word when it is used as
the first word of a simple command. The shell maintains a list of
aliases that may be set and unset with the aalliiaass and uunnaalliiaass builtin
commands (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). The first word of each
simple command, if unquoted, is checked to see if it has an alias. If
so, that word is replaced by the text of the alias. The characters //,
$$, ``, and == and any of the shell _m_e_t_a_c_h_a_r_a_c_t_e_r_s 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 llss to llss --FF, for instance, and
bbaasshh does not try to recursively expand the replacement text. If the
last character of the alias value is a _b_l_a_n_k, 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 llss to llss --FF, for instance, and
bbaasshh does not try to recursively expand the replacement text. If the
last character of the alias value is a _b_l_a_n_k, then the next command
word following the alias is also checked for alias expansion.
Aliases are created and listed with the aalliiaass command, and removed with
the uunnaalliiaass command.
There is no mechanism for using arguments in the replacement text. If
arguments are needed, a shell function should be used (see FFUUNNCCTTIIOONNSS
There is no mechanism for using arguments in the replacement text. If
arguments are needed, a shell function should be used (see FFUUNNCCTTIIOONNSS
below).
Aliases are not expanded when the shell is not interactive, unless the
eexxppaanndd__aalliiaasseess shell option is set using sshhoopptt (see the description of
Aliases are not expanded when the shell is not interactive, unless the
eexxppaanndd__aalliiaasseess shell option is set using sshhoopptt (see the description of
sshhoopptt under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below).
The rules concerning the definition and use of aliases are somewhat
confusing. BBaasshh 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. BBaasshh 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-
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 aalliiaass in compound
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 aalliiaass in compound
commands.
For almost every purpose, aliases are superseded by shell functions.
FFUUNNCCTTIIOONNSS
A shell function, defined as described above under SSHHEELLLL GGRRAAMMMMAARR,
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 SSHHEELLLL GGRRAAMMMMAARR,
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 ## is
updated to reflect the change. Special parameter 00 is unchanged. The
first element of the FFUUNNCCNNAAMMEE variable is set to the name of the func-
updated to reflect the change. Special parameter 00 is unchanged. The
first element of the FFUUNNCCNNAAMMEE 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 DDEEBBUUGG and
RREETTUURRNN traps (see the description of the ttrraapp builtin under SSHHEELLLL
BBUUIILLTTIINN CCOOMMMMAANNDDSS below) are not inherited unless the function has been
given the ttrraaccee attribute (see the description of the ddeeccllaarree builtin
below) or the --oo ffuunnccttrraaccee shell option has been enabled with the sseett
builtin (in which case all functions inherit the DDEEBBUUGG and RREETTUURRNN
traps), and the EERRRR trap is not inherited unless the --oo eerrrrttrraaccee shell
All other aspects of the shell execution environment are identical
between a function and its caller with these exceptions: the DDEEBBUUGG and
RREETTUURRNN traps (see the description of the ttrraapp builtin under SSHHEELLLL
BBUUIILLTTIINN CCOOMMMMAANNDDSS below) are not inherited unless the function has been
given the ttrraaccee attribute (see the description of the ddeeccllaarree builtin
below) or the --oo ffuunnccttrraaccee shell option has been enabled with the sseett
builtin (in which case all functions inherit the DDEEBBUUGG and RREETTUURRNN
traps), and the EERRRR trap is not inherited unless the --oo eerrrrttrraaccee shell
option has been enabled.
Variables local to the function may be declared with the llooccaall builtin
Variables local to the function may be declared with the llooccaall builtin
command. Ordinarily, variables and their values are shared between the
function and its caller.
function and its caller. If a variable is declared llooccaall, the vari-
able's visible scope is restricted to that function and its children
(including the functions it calls). Local variables "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 refer to the local variable, leaving
the global variable unmodified. When the function returns, the global
variable is once again visible.
The shell uses _d_y_n_a_m_i_c _s_c_o_p_i_n_g to control a variable's visibility
within functions. With dynamic scoping, visible variables and their
values are a result of the sequence of function calls that caused exe-
cution to reach the current function. The value of a variable that a
function sees depends on its value within its caller, if any, whether
that caller is the "global" scope or another shell function. This is
also the value that a local variable declaration "shadows", and the
value that is restored when the function returns.
For example, if a variable _v_a_r is declared as local in function _f_u_n_c_1,
and _f_u_n_c_1 calls another function _f_u_n_c_2, references to _v_a_r made from
within _f_u_n_c_2 will resolve to the local variable _v_a_r from _f_u_n_c_1, shadow-
ing any global variable named _v_a_r.
The FFUUNNCCNNEESSTT variable, if set to a numeric value greater than 0,
defines a maximum function nesting level. Function invocations that
@@ -2499,7 +2519,9 @@ CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS
binary operators return true if _a_r_g_1 is equal to, not equal to,
less than, less than or equal to, greater than, or greater than
or equal to _a_r_g_2, respectively. _A_r_g_1 and _a_r_g_2 may be positive
or negative integers.
or negative integers. When used with the [[[[ command, _A_r_g_1 and
_A_r_g_2 are evaluated as arithmetic expressions (see AARRIITTHHMMEETTIICC
EEVVAALLUUAATTIIOONN above).
SSIIMMPPLLEE CCOOMMMMAANNDD EEXXPPAANNSSIIOONN
When a simple command is executed, the shell performs the following
@@ -2836,9 +2858,11 @@ PPRROOMMPPTTIINNGG
When executing interactively, bbaasshh displays the primary prompt PPSS11 when
it is ready to read a command, and the secondary prompt PPSS22 when it
needs more input to complete a command. BBaasshh displays PPSS00 after it
reads a command but before executing it. BBaasshh allows these prompt
strings to be customized by inserting a number of backslash-escaped
special characters that are decoded as follows:
reads a command but before executing it. BBaasshh displays PPSS44 as
described above before tracing each command when the --xx option is
enabled. BBaasshh allows these prompt strings to be customized by insert-
ing a number of backslash-escaped special characters that are decoded
as follows:
\\aa an ASCII bell character (07)
\\dd the date in "Weekday Month Date" format (e.g., "Tue May
26")
@@ -3369,6 +3393,18 @@ RREEAADDLLIINNEE
sshheellll--bbaacckkwwaarrdd--wwoorrdd
Move back to the start of the current or previous word. Words
are delimited by non-quoted shell metacharacters.
pprreevviioouuss--ssccrreeeenn--lliinnee
Attempt to move point to the same physical screen column on the
previous physical screen line. This will not have the desired
effect if the current Readline line does not take up more than
one physical line or if point is not greater than the length of
the prompt plus the screen width.
nneexxtt--ssccrreeeenn--lliinnee
Attempt to move point to the same physical screen column on the
next physical screen line. This will not have the desired effect
if the current Readline line does not take up more than one
physical line or if the length of the current Readline line is
not greater than the length of the prompt plus the screen width.
cclleeaarr--ssccrreeeenn ((CC--ll))
Clear the screen leaving the current line at the top of the
screen. With an argument, refresh the current line without
@@ -5989,4 +6025,4 @@ BBUUGGSS
GNU Bash 4.4 2017 February 1 BASH(1)
GNU Bash 4.4 2017 March 22 BASH(1)