pmodules/bash
0
0
Fork 0
mirror of https://https.git.savannah.gnu.org/git/bash.git synced 2026-08-09 11:40:30 +02:00
Code Issues Packages Projects Releases Wiki Activity

fixes for $LINENO in multi-line simple commands; printf out-of-range values now cause a non-zero return status

Browse Source
This commit is contained in:
Chet Ramey
2023-07-28 11:35:44 -04:00
parent 8418224f32
commit f6a78e24d8
24 changed files with 965 additions and 863 deletions
Download Patch File Download Diff File Expand all files Collapse all files
doc/bash.0
+244 -243
View File
@@ -5065,10 +5065,10 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
characters is enabled. The --EE option disables the interpreta-
tion of these escape characters, even on systems where they are
interpreted by default. The xxppgg__eecchhoo shell option may be used
to dynamically determine whether or not eecchhoo expands these es-
cape characters by default. eecchhoo does not interpret ---- to mean
the end of options. eecchhoo interprets the following escape se-
quences:
to dynamically determine whether or not eecchhoo interprets any op-
tions and expands these escape characters by default. eecchhoo does
not interpret ---- to mean the end of options. eecchhoo interprets
the following escape sequences:
\\aa alert (bell)
\\bb backspace
\\cc suppress further output
@@ -6248,32 +6248,33 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
xxppgg__eecchhoo
If set, the eecchhoo builtin expands backslash-escape se-
quences by default.
quences by default. If the ppoossiixx shell option is also
enabled, eecchhoo does not interpret any options.
ssuussppeenndd [--ff]
Suspend the execution of this shell until it receives a SSIIGGCCOONNTT
signal. A login shell, or a shell without job control enabled,
cannot be suspended; the --ff option can be used to override this
and force the suspension. The return status is 0 unless the
shell is a login shell or job control is not enabled and --ff is
Suspend the execution of this shell until it receives a SSIIGGCCOONNTT
signal. A login shell, or a shell without job control enabled,
cannot be suspended; the --ff option can be used to override this
and force the suspension. The return status is 0 unless the
shell is a login shell or job control is not enabled and --ff is
not supplied.
tteesstt _e_x_p_r
[[ _e_x_p_r ]]
Return a status of 0 (true) or 1 (false) depending on the evalu-
ation of the conditional expression _e_x_p_r. Each operator and op-
erand must be a separate argument. Expressions are composed of
the primaries described above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS.
tteesstt does not accept any options, nor does it accept and ignore
erand must be a separate argument. Expressions are composed of
the primaries described above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS.
tteesstt does not accept any options, nor does it accept and ignore
an argument of ---- as signifying the end of options.
Expressions may be combined using the following operators,
listed in decreasing order of precedence. The evaluation de-
pends on the number of arguments; see below. Operator prece-
Expressions may be combined using the following operators,
listed in decreasing order of precedence. The evaluation de-
pends on the number of arguments; see below. Operator prece-
dence is used when there are five or more arguments.
!! _e_x_p_r True if _e_x_p_r is false.
(( _e_x_p_r ))
Returns the value of _e_x_p_r. This may be used to override
Returns the value of _e_x_p_r. This may be used to override
the normal precedence of operators.
_e_x_p_r_1 -aa _e_x_p_r_2
True if both _e_x_p_r_1 and _e_x_p_r_2 are true.
@@ -6290,161 +6291,161 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
null.
2 arguments
If the first argument is !!, 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 CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, 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 CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the expression is
true if the unary test is true. If the first argument is
not a valid unary conditional operator, the expression is
false.
3 arguments
The following conditions are applied in the order listed.
If the second argument is one of the binary conditional
If the second argument is one of the binary conditional
operators listed above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the
result of the expression is the result of the binary test
using the first and third arguments as operands. The --aa
and --oo operators are considered binary operators when
there are three arguments. If the first argument is !!,
the value is the negation of the two-argument test using
using the first and third arguments as operands. The --aa
and --oo operators are considered binary operators when
there are three arguments. If the first argument is !!,
the value is the negation of the two-argument test using
the second and third arguments. If the first argument is
exactly (( and the third argument is exactly )), the result
is the one-argument test of the second argument. Other-
is the one-argument test of the second argument. Other-
wise, the expression is false.
4 arguments
The following conditions are applied in the order listed.
If the first argument is !!, the result is the negation of
the three-argument expression composed of the remaining
arguments. the two-argument test using the second and
third arguments. If the first argument is exactly (( and
the fourth argument is exactly )), the result is the two-
argument test of the second and third arguments. Other-
the three-argument expression composed of the remaining
arguments. the two-argument test using the second and
third arguments. If the first argument is exactly (( and
the fourth argument is exactly )), the result is the two-
argument test of the second and third arguments. Other-
wise, the expression is parsed and evaluated according to
precedence using the rules listed above.
5 or more arguments
The expression is parsed and evaluated according to
The expression is parsed and evaluated according to
precedence using the rules listed above.
If the shell is not in _p_o_s_i_x _m_o_d_e, when used with tteesstt or [[, the
<< and >> operators sort lexicographically using ASCII ordering.
When the shell is in _p_o_s_i_x _m_o_d_e, these operators sort using the
<< and >> operators sort lexicographically using ASCII ordering.
When the shell is in _p_o_s_i_x _m_o_d_e, these operators sort using the
current locale.
ttiimmeess Print the accumulated user and system times for the shell and
ttiimmeess Print the accumulated user and system times for the shell and
for processes run from the shell. The return status is 0.
ttrraapp [--llpp] [[_a_c_t_i_o_n] _s_i_g_s_p_e_c ...]
The _a_c_t_i_o_n is a command that is read and executed when the shell
receives signal(s) _s_i_g_s_p_e_c. If _a_c_t_i_o_n is absent (and there is a
single _s_i_g_s_p_e_c) or --, each specified signal is reset to its
original disposition (the value it had upon entrance to the
shell). If _a_c_t_i_o_n is the null string the signal specified by
each _s_i_g_s_p_e_c is ignored by the shell and by the commands it in-
single _s_i_g_s_p_e_c) or --, each specified signal is reset to its
original disposition (the value it had upon entrance to the
shell). If _a_c_t_i_o_n is the null string the signal specified by
each _s_i_g_s_p_e_c is ignored by the shell and by the commands it in-
vokes.
If no arguments are supplied, ttrraapp displays the actions associ-
If no arguments are supplied, ttrraapp displays the actions associ-
ated with each trapped signal as a set of ttrraapp commands that can
be reused as shell input to restore the current signal disposi-
tions. If --pp is given, and _a_c_t_i_o_n is not present, then ttrraapp
displays the actions associated with each _s_i_g_s_p_e_c or, if none
be reused as shell input to restore the current signal disposi-
tions. If --pp is given, and _a_c_t_i_o_n is not present, then ttrraapp
displays the actions associated with each _s_i_g_s_p_e_c or, if none
are supplied, for all trapped signals, as a set of ttrraapp commands
that can be reused as shell input to restore the current signal
dispositions. The --PP option behaves similarly, but displays
only the actions associated with each _s_i_g_s_p_e_c argument. --PP re-
quires at least one _s_i_g_s_p_e_c argument. The --PP or --pp options to
ttrraapp may be used in a subshell environment (e.g., command sub-
stitution) and, as long as they are used before ttrraapp is used to
change a signal's handling, will display the state of its par-
that can be reused as shell input to restore the current signal
dispositions. The --PP option behaves similarly, but displays
only the actions associated with each _s_i_g_s_p_e_c argument. --PP re-
quires at least one _s_i_g_s_p_e_c argument. The --PP or --pp options to
ttrraapp may be used in a subshell environment (e.g., command sub-
stitution) and, as long as they are used before ttrraapp is used to
change a signal's handling, will display the state of its par-
ent's traps.
The --ll option causes ttrraapp to print a list of signal names and
their corresponding numbers. Each _s_i_g_s_p_e_c is either a signal
name defined in <_s_i_g_n_a_l_._h>, or a signal number. Signal names
The --ll option causes ttrraapp to print a list of signal names and
their corresponding numbers. Each _s_i_g_s_p_e_c is either a signal
name defined in <_s_i_g_n_a_l_._h>, or a signal number. Signal names
are case insensitive and the SSIIGG prefix is optional.
If a _s_i_g_s_p_e_c is EEXXIITT (0) the command _a_c_t_i_o_n is executed on exit
from the shell. If a _s_i_g_s_p_e_c is DDEEBBUUGG, the command _a_c_t_i_o_n is
If a _s_i_g_s_p_e_c is EEXXIITT (0) the command _a_c_t_i_o_n is executed on exit
from the shell. If a _s_i_g_s_p_e_c is DDEEBBUUGG, the command _a_c_t_i_o_n is
executed before every _s_i_m_p_l_e _c_o_m_m_a_n_d, _f_o_r command, _c_a_s_e command,
_s_e_l_e_c_t command, (( arithmetic command, [[ conditional command,
_s_e_l_e_c_t command, (( arithmetic command, [[ conditional command,
arithmetic _f_o_r command, and before the first command executes in
a shell function (see SSHHEELLLL GGRRAAMMMMAARR above). Refer to the de-
scription of the eexxttddeebbuugg option to the sshhoopptt builtin for de-
tails of its effect on the DDEEBBUUGG trap. If a _s_i_g_s_p_e_c is RREETTUURRNN,
the command _a_c_t_i_o_n is executed each time a shell function or a
script executed with the .. or ssoouurrccee builtins finishes execut-
a shell function (see SSHHEELLLL GGRRAAMMMMAARR above). Refer to the de-
scription of the eexxttddeebbuugg option to the sshhoopptt builtin for de-
tails of its effect on the DDEEBBUUGG trap. If a _s_i_g_s_p_e_c is RREETTUURRNN,
the command _a_c_t_i_o_n is executed each time a shell function or a
script executed with the .. or ssoouurrccee builtins finishes execut-
ing.
If a _s_i_g_s_p_e_c is EERRRR, the command _a_c_t_i_o_n is executed whenever a
If a _s_i_g_s_p_e_c is EERRRR, the command _a_c_t_i_o_n 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 EERRRR trap is not executed if the
the following conditions. The EERRRR trap is not executed if the
failed command is part of the command list immediately following
a wwhhiillee or uunnttiill keyword, part of the test in an _i_f statement,
a wwhhiillee or uunnttiill keyword, part of the test in an _i_f statement,
part of a command executed in a &&&& or |||| list except the command
following the final &&&& or ||||, any command in a pipeline but the
last, or if the command's return value is being inverted using
following the final &&&& or ||||, any command in a pipeline but the
last, or if the command's return value is being inverted using
!!. These are the same conditions obeyed by the eerrrreexxiitt (--ee) op-
tion.
When the shell is not interactive, signals ignored upon entry to
the shell cannot be trapped or reset. Interactive shells permit
trapping signals ignored on entry. Trapped signals that are not
being ignored are reset to their original values in a subshell
or subshell environment when one is created. The return status
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 _s_i_g_s_p_e_c is invalid; otherwise ttrraapp returns true.
ttrruuee Does nothing, returns a 0 status.
ttyyppee [--aaffttppPP] _n_a_m_e [_n_a_m_e ...]
With no options, indicate how each _n_a_m_e would be interpreted if
With no options, indicate how each _n_a_m_e would be interpreted if
used as a command name. If the --tt option is used, ttyyppee prints a
string which is one of _a_l_i_a_s, _k_e_y_w_o_r_d, _f_u_n_c_t_i_o_n, _b_u_i_l_t_i_n, or
_f_i_l_e if _n_a_m_e is an alias, shell reserved word, function,
builtin, or executable disk file, respectively. If the _n_a_m_e is
not found, then nothing is printed, and ttyyppee returns a non-zero
exit status. If the --pp option is used, ttyyppee either returns the
name of the executable file that would be found by searching
$$PPAATTHH if _n_a_m_e were specified as a command name, or nothing if
``type -t name'' would not return _f_i_l_e. The --PP option forces a
PPAATTHH search for each _n_a_m_e, even if ``type -t name'' would not
string which is one of _a_l_i_a_s, _k_e_y_w_o_r_d, _f_u_n_c_t_i_o_n, _b_u_i_l_t_i_n, or
_f_i_l_e if _n_a_m_e is an alias, shell reserved word, function,
builtin, or executable disk file, respectively. If the _n_a_m_e is
not found, then nothing is printed, and ttyyppee returns a non-zero
exit status. If the --pp option is used, ttyyppee either returns the
name of the executable file that would be found by searching
$$PPAATTHH if _n_a_m_e were specified as a command name, or nothing if
``type -t name'' would not return _f_i_l_e. The --PP option forces a
PPAATTHH search for each _n_a_m_e, even if ``type -t name'' would not
return _f_i_l_e. If a command is hashed, --pp and --PP print the hashed
value, which is not necessarily the file that appears first in
PPAATTHH. If the --aa option is used, ttyyppee prints all of the places
that contain a command named _n_a_m_e. This includes aliases, re-
served words, functions, and builtins, but the path search op-
value, which is not necessarily the file that appears first in
PPAATTHH. If the --aa option is used, ttyyppee prints all of the places
that contain a command named _n_a_m_e. This includes aliases, re-
served words, functions, and builtins, but the path search op-
tions (--pp and --PP) can be supplied to restrict the output to exe-
cutable files. ttyyppee does not consult the table of hashed com-
cutable files. ttyyppee does not consult the table of hashed com-
mands when using --aa with --pp, and only performs a PPAATTHH search for
_n_a_m_e. The --ff option suppresses shell function lookup, as with
the ccoommmmaanndd builtin. ttyyppee returns true if all of the arguments
_n_a_m_e. The --ff option suppresses shell function lookup, as with
the ccoommmmaanndd builtin. ttyyppee returns true if all of the arguments
are found, false if any are not found.
uulliimmiitt [--HHSS] --aa
uulliimmiitt [--HHSS] [--bbccddeeffiikkllmmnnppqqrrssttuuvvxxPPRRTT [_l_i_m_i_t]]
Provides control over the resources available to the shell and
to processes started by it, on systems that allow such control.
Provides control over the resources available to the shell and
to processes started by it, on systems that allow such control.
The --HH and --SS 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 --HH nor --SS 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 --HH nor --SS is speci-
fied, both the soft and hard limits are set. The value of _l_i_m_i_t
can be a number in the unit specified for the resource or one of
the special values hhaarrdd, ssoofftt, or uunnlliimmiitteedd, which stand for the
current hard limit, the current soft limit, and no limit, re-
spectively. If _l_i_m_i_t is omitted, the current value of the soft
current hard limit, the current soft limit, and no limit, re-
spectively. If _l_i_m_i_t is omitted, the current value of the soft
limit of the resource is printed, unless the --HH option is given.
When more than one resource is specified, the limit name and
unit, if appropriate, are printed before the value. Other op-
When more than one resource is specified, the limit name and
unit, if appropriate, are printed before the value. Other op-
tions are interpreted as follows:
--aa All current limits are reported; no limits are set
--bb The maximum socket buffer size
--cc The maximum size of core files created
--dd The maximum size of a process's data segment
--ee The maximum scheduling priority ("nice")
--ff The maximum size of files written by the shell and its
--ff The maximum size of files written by the shell and its
children
--ii The maximum number of pending signals
--kk The maximum number of kqueues that may be allocated
--ll The maximum size that may be locked into memory
--mm The maximum resident set size (many systems do not honor
--mm The maximum resident set size (many systems do not honor
this limit)
--nn The maximum number of open file descriptors (most systems
do not allow this value to be set)
@@ -6453,134 +6454,134 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS
--rr The maximum real-time scheduling priority
--ss The maximum stack size
--tt The maximum amount of cpu time in seconds
--uu The maximum number of processes available to a single
--uu The maximum number of processes available to a single
user
--vv The maximum amount of virtual memory available to the
--vv The maximum amount of virtual memory available to the
shell and, on some systems, to its children
--xx The maximum number of file locks
--PP The maximum number of pseudoterminals
--RR The maximum time a real-time process can run before
--RR The maximum time a real-time process can run before
blocking, in microseconds
--TT The maximum number of threads
If _l_i_m_i_t is given, and the --aa option is not used, _l_i_m_i_t is the
new value of the specified resource. If no option is given,
then --ff is assumed. Values are in 1024-byte increments, except
for --tt, which is in seconds; --RR, which is in microseconds; --pp,
which is in units of 512-byte blocks; --PP, --TT, --bb, --kk, --nn, and
--uu, which are unscaled values; and, when in posix mode, --cc and
--ff, which are in 512-byte increments. The return status is 0
unless an invalid option or argument is supplied, or an error
If _l_i_m_i_t is given, and the --aa option is not used, _l_i_m_i_t is the
new value of the specified resource. If no option is given,
then --ff is assumed. Values are in 1024-byte increments, except
for --tt, which is in seconds; --RR, which is in microseconds; --pp,
which is in units of 512-byte blocks; --PP, --TT, --bb, --kk, --nn, and
--uu, which are unscaled values; and, when in posix mode, --cc and
--ff, which are in 512-byte increments. The return status is 0
unless an invalid option or argument is supplied, or an error
occurs while setting a new limit.
uummaasskk [--pp] [--SS] [_m_o_d_e]
The user file-creation mask is set to _m_o_d_e. If _m_o_d_e begins with
a digit, it is interpreted as an octal number; otherwise it is
interpreted as a symbolic mode mask similar to that accepted by
_c_h_m_o_d(1). If _m_o_d_e is omitted, the current value of the mask is
printed. The --SS option causes the mask to be printed in sym-
bolic form; the default output is an octal number. If the --pp
a digit, it is interpreted as an octal number; otherwise it is
interpreted as a symbolic mode mask similar to that accepted by
_c_h_m_o_d(1). If _m_o_d_e is omitted, the current value of the mask is
printed. The --SS option causes the mask to be printed in sym-
bolic form; the default output is an octal number. If the --pp
option is supplied, and _m_o_d_e is omitted, the output is in a form
that may be reused as input. The return status is 0 if the mode
was successfully changed or if no _m_o_d_e argument was supplied,
was successfully changed or if no _m_o_d_e argument was supplied,
and false otherwise.
uunnaalliiaass [-aa] [_n_a_m_e ...]
Remove each _n_a_m_e from the list of defined aliases. If --aa is
supplied, all alias definitions are removed. The return value
Remove each _n_a_m_e from the list of defined aliases. If --aa is
supplied, all alias definitions are removed. The return value
is true unless a supplied _n_a_m_e is not a defined alias.
uunnsseett [-ffvv] [-nn] [_n_a_m_e ...]
For each _n_a_m_e, remove the corresponding variable or function.
For each _n_a_m_e, remove the corresponding variable or function.
If the --vv option is given, each _n_a_m_e refers to a shell variable,
and that variable is removed. Read-only variables may not be
unset. If --ff is specified, each _n_a_m_e refers to a shell func-
tion, and the function definition is removed. If the --nn option
is supplied, and _n_a_m_e is a variable with the _n_a_m_e_r_e_f attribute,
_n_a_m_e will be unset rather than the variable it references. --nn
has no effect if the --ff option is supplied. If no options are
supplied, each _n_a_m_e refers to a variable; if there is no vari-
able by that name, a function with that name, if any, is unset.
Each unset variable or function is removed from the environment
passed to subsequent commands. If any of BBAASSHH__AALLIIAASSEESS,
and that variable is removed. Read-only variables may not be
unset. If --ff is specified, each _n_a_m_e refers to a shell func-
tion, and the function definition is removed. If the --nn option
is supplied, and _n_a_m_e is a variable with the _n_a_m_e_r_e_f attribute,
_n_a_m_e will be unset rather than the variable it references. --nn
has no effect if the --ff option is supplied. If no options are
supplied, each _n_a_m_e refers to a variable; if there is no vari-
able by that name, a function with that name, if any, is unset.
Each unset variable or function is removed from the environment
passed to subsequent commands. If any of BBAASSHH__AALLIIAASSEESS,
BBAASSHH__AARRGGVV00, BBAASSHH__CCMMDDSS, BBAASSHH__CCOOMMMMAANNDD, BBAASSHH__SSUUBBSSHHEELLLL, BBAASSHHPPIIDD,
CCOOMMPP__WWOORRDDBBRREEAAKKSS, DDIIRRSSTTAACCKK, EEPPOOCCHHRREEAALLTTIIMMEE, EEPPOOCCHHSSEECCOONNDDSS, FFUUNNCC--
NNAAMMEE, GGRROOUUPPSS, HHIISSTTCCMMDD, LLIINNEENNOO, RRAANNDDOOMM, SSEECCOONNDDSS, or SSRRAANNDDOOMM are
CCOOMMPP__WWOORRDDBBRREEAAKKSS, DDIIRRSSTTAACCKK, EEPPOOCCHHRREEAALLTTIIMMEE, EEPPOOCCHHSSEECCOONNDDSS, FFUUNNCC--
NNAAMMEE, GGRROOUUPPSS, HHIISSTTCCMMDD, LLIINNEENNOO, RRAANNDDOOMM, SSEECCOONNDDSS, or SSRRAANNDDOOMM are
unset, they lose their special properties, even if they are sub-
sequently reset. The exit status is true unless a _n_a_m_e is read-
only or may not be unset.
wwaaiitt [--ffnn] [--pp _v_a_r_n_a_m_e] [_i_d _._._.]
Wait for each specified child process and return its termination
status. Each _i_d 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 _i_d is not given, wwaaiitt waits for all running
background jobs and the last-executed process substitution, if
status. Each _i_d 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 _i_d is not given, wwaaiitt waits for all running
background jobs and the last-executed process substitution, if
its process id is the same as $$!!, and the return status is zero.
If the --nn option is supplied, wwaaiitt waits for a single job from
If the --nn option is supplied, wwaaiitt waits for a single job from
the list of _i_ds or, if no _i_ds are supplied, any job, to complete
and returns its exit status. If none of the supplied arguments
and returns its exit status. If none of the supplied arguments
is a child of the shell, or if no arguments are supplied and the
shell has no unwaited-for children, the exit status is 127. If
the --pp option is supplied, the process or job identifier of the
job for which the exit status is returned is assigned to the
variable _v_a_r_n_a_m_e named by the option argument. The variable
will be unset initially, before any assignment. This is useful
only when the --nn option is supplied. Supplying the --ff option,
when job control is enabled, forces wwaaiitt to wait for _i_d to ter-
shell has no unwaited-for children, the exit status is 127. If
the --pp option is supplied, the process or job identifier of the
job for which the exit status is returned is assigned to the
variable _v_a_r_n_a_m_e named by the option argument. The variable
will be unset initially, before any assignment. This is useful
only when the --nn option is supplied. Supplying the --ff option,
when job control is enabled, forces wwaaiitt to wait for _i_d to ter-
minate before returning its status, instead of returning when it
changes status. If _i_d specifies a non-existent process or job,
the return status is 127. If wwaaiitt is interrupted by a signal,
the return status will be greater than 128, as described under
SSIIGGNNAALLSS above. Otherwise, the return status is the exit status
changes status. If _i_d specifies a non-existent process or job,
the return status is 127. If wwaaiitt is interrupted by a signal,
the return status will be greater than 128, as described under
SSIIGGNNAALLSS above. Otherwise, the return status is the exit status
of the last process or job waited for.
SSHHEELLLL CCOOMMPPAATTIIBBIILLIITTYY MMOODDEE
Bash-4.0 introduced the concept of a _s_h_e_l_l _c_o_m_p_a_t_i_b_i_l_i_t_y _l_e_v_e_l, speci-
fied as a set of options to the shopt builtin ( ccoommppaatt3311, ccoommppaatt3322,
ccoommppaatt4400, ccoommppaatt4411, and so on). There is only one current compatibil-
ity level -- each option is mutually exclusive. The compatibility
level is intended to allow users to select behavior from previous ver-
sions that is incompatible with newer versions while they migrate
scripts to use current features and behavior. It's intended to be a
Bash-4.0 introduced the concept of a _s_h_e_l_l _c_o_m_p_a_t_i_b_i_l_i_t_y _l_e_v_e_l, speci-
fied as a set of options to the shopt builtin ( ccoommppaatt3311, ccoommppaatt3322,
ccoommppaatt4400, ccoommppaatt4411, and so on). There is only one current compatibil-
ity level -- each option is mutually exclusive. The compatibility
level is intended to allow users to select behavior from previous ver-
sions that is incompatible with newer versions while they migrate
scripts to use current features and behavior. It's intended to be a
temporary solution.
This section does not mention behavior that is standard for a particu-
lar version (e.g., setting ccoommppaatt3322 means that quoting the rhs of the
regexp matching operator quotes special regexp characters in the word,
This section does not mention behavior that is standard for a particu-
lar version (e.g., setting ccoommppaatt3322 means that quoting the rhs of the
regexp matching operator quotes special regexp characters in the word,
which is default behavior in bash-3.2 and subsequent versions).
If a user enables, say, ccoommppaatt3322, it may affect the behavior of other
compatibility levels up to and including the current compatibility
level. The idea is that each compatibility level controls behavior
that changed in that version of bbaasshh, but that behavior may have been
present in earlier versions. For instance, the change to use locale-
based comparisons with the [[[[ command came in bash-4.1, and earlier
If a user enables, say, ccoommppaatt3322, it may affect the behavior of other
compatibility levels up to and including the current compatibility
level. The idea is that each compatibility level controls behavior
that changed in that version of bbaasshh, but that behavior may have been
present in earlier versions. For instance, the change to use locale-
based comparisons with the [[[[ command came in bash-4.1, and earlier
versions used ASCII-based comparisons, so enabling ccoommppaatt3322 will enable
ASCII-based comparisons as well. That granularity may not be suffi-
cient for all uses, and as a result users should employ compatibility
levels carefully. Read the documentation for a particular feature to
ASCII-based comparisons as well. That granularity may not be suffi-
cient for all uses, and as a result users should employ compatibility
levels carefully. Read the documentation for a particular feature to
find out the current behavior.
Bash-4.3 introduced a new shell variable: BBAASSHH__CCOOMMPPAATT. The value as-
Bash-4.3 introduced a new shell variable: BBAASSHH__CCOOMMPPAATT. The value as-
signed to this variable (a decimal version number like 4.2, or an inte-
ger corresponding to the ccoommppaatt_N_N option, like 42) determines the com-
ger corresponding to the ccoommppaatt_N_N option, like 42) determines the com-
patibility level.
Starting with bash-4.4, Bash has begun deprecating older compatibility
levels. Eventually, the options will be removed in favor of BBAASSHH__CCOOMM--
Starting with bash-4.4, Bash has begun deprecating older compatibility
levels. Eventually, the options will be removed in favor of BBAASSHH__CCOOMM--
PPAATT.
Bash-5.0 is the final version for which there will be an individual
shopt option for the previous version. Users should use BBAASSHH__CCOOMMPPAATT on
Bash-5.0 is the final version for which there will be an individual
shopt option for the previous version. Users should use BBAASSHH__CCOOMMPPAATT on
bash-5.0 and later versions.
The following table describes the behavior changes controlled by each
The following table describes the behavior changes controlled by each
compatibility level setting. The ccoommppaatt_N_N tag is used as shorthand for
setting the compatibility level to _N_N using one of the following mecha-
nisms. For versions prior to bash-5.0, the compatibility level may be
set using the corresponding ccoommppaatt_N_N shopt option. For bash-4.3 and
later versions, the BBAASSHH__CCOOMMPPAATT variable is preferred, and it is re-
nisms. For versions prior to bash-5.0, the compatibility level may be
set using the corresponding ccoommppaatt_N_N shopt option. For bash-4.3 and
later versions, the BBAASSHH__CCOOMMPPAATT variable is preferred, and it is re-
quired for bash-5.1 and later versions.
ccoommppaatt3311
@@ -6588,114 +6589,114 @@ SSHHEELLLL CCOOMMPPAATTIIBBIILLIITTYY MMOODDEE
ator (=~) has no special effect
ccoommppaatt3322
+o interrupting a command list such as "a ; b ; c" causes
the execution of the next command in the list (in
bash-4.0 and later versions, the shell acts as if it re-
ceived the interrupt, so interrupting one command in a
+o interrupting a command list such as "a ; b ; c" causes
the execution of the next command in the list (in
bash-4.0 and later versions, the shell acts as if it re-
ceived the interrupt, so interrupting one command in a
list aborts the execution of the entire list)
ccoommppaatt4400
+o the << and >> operators to the [[[[ command do not consider
+o the << and >> operators to the [[[[ command do not consider
the current locale when comparing strings; they use ASCII
ordering. Bash versions prior to bash-4.1 use ASCII col-
lation and _s_t_r_c_m_p(3); bash-4.1 and later use the current
lation and _s_t_r_c_m_p(3); bash-4.1 and later use the current
locale's collation sequence and _s_t_r_c_o_l_l(3).
ccoommppaatt4411
+o in _p_o_s_i_x mode, ttiimmee may be followed by options and still
+o in _p_o_s_i_x mode, ttiimmee may be followed by options and still
be recognized as a reserved word (this is POSIX interpre-
tation 267)
+o in _p_o_s_i_x mode, the parser requires that an even number of
single quotes occur in the _w_o_r_d portion of a double-
quoted parameter expansion and treats them specially, so
that characters within the single quotes are considered
single quotes occur in the _w_o_r_d portion of a double-
quoted parameter expansion and treats them specially, so
that characters within the single quotes are considered
quoted (this is POSIX interpretation 221)
ccoommppaatt4422
+o the replacement string in double-quoted pattern substitu-
tion does not undergo quote removal, as it does in ver-
tion does not undergo quote removal, as it does in ver-
sions after bash-4.2
+o in posix mode, single quotes are considered special when
expanding the _w_o_r_d portion of a double-quoted parameter
expansion and can be used to quote a closing brace or
other special character (this is part of POSIX interpre-
tation 221); in later versions, single quotes are not
+o in posix mode, single quotes are considered special when
expanding the _w_o_r_d portion of a double-quoted parameter
expansion and can be used to quote a closing brace or
other special character (this is part of POSIX interpre-
tation 221); in later versions, single quotes are not
special within double-quoted word expansions
ccoommppaatt4433
+o the shell does not print a warning message if an attempt
is made to use a quoted compound assignment as an argu-
ment to declare (e.g., declare -a foo='(1 2)'). Later
+o the shell does not print a warning message if an attempt
is made to use a quoted compound assignment as an argu-
ment to declare (e.g., declare -a foo='(1 2)'). Later
versions warn that this usage is deprecated
+o word expansion errors are considered non-fatal errors
that cause the current command to fail, even in posix
mode (the default behavior is to make them fatal errors
+o word expansion errors are considered non-fatal errors
that cause the current command to fail, even in posix
mode (the default behavior is to make them fatal errors
that cause the shell to exit)
+o when executing a shell function, the loop state
+o when executing a shell function, the loop state
(while/until/etc.) is not reset, so bbrreeaakk or ccoonnttiinnuuee in
that function will break or continue loops in the calling
context. Bash-4.4 and later reset the loop state to pre-
context. Bash-4.4 and later reset the loop state to pre-
vent this
ccoommppaatt4444
+o the shell sets up the values used by BBAASSHH__AARRGGVV and
BBAASSHH__AARRGGCC so they can expand to the shell's positional
+o the shell sets up the values used by BBAASSHH__AARRGGVV and
BBAASSHH__AARRGGCC so they can expand to the shell's positional
parameters even if extended debugging mode is not enabled
+o a subshell inherits loops from its parent context, so
bbrreeaakk or ccoonnttiinnuuee will cause the subshell to exit.
Bash-5.0 and later reset the loop state to prevent the
+o a subshell inherits loops from its parent context, so
bbrreeaakk or ccoonnttiinnuuee will cause the subshell to exit.
Bash-5.0 and later reset the loop state to prevent the
exit
+o variable assignments preceding builtins like eexxppoorrtt and
+o variable assignments preceding builtins like eexxppoorrtt and
rreeaaddoonnllyy that set attributes continue to affect variables
with the same name in the calling environment even if the
shell is not in posix mode
ccoommppaatt5500
+o Bash-5.1 changed the way $$RRAANNDDOOMM is generated to intro-
+o Bash-5.1 changed the way $$RRAANNDDOOMM is generated to intro-
duce slightly more randomness. If the shell compatibility
level is set to 50 or lower, it reverts to the method
from bash-5.0 and previous versions, so seeding the ran-
dom number generator by assigning a value to RRAANNDDOOMM will
level is set to 50 or lower, it reverts to the method
from bash-5.0 and previous versions, so seeding the ran-
dom number generator by assigning a value to RRAANNDDOOMM will
produce the same sequence as in bash-5.0
+o If the command hash table is empty, bash versions prior
to bash-5.1 printed an informational message to that ef-
fect, even when producing output that can be reused as
input. Bash-5.1 suppresses that message when the --ll op-
+o If the command hash table is empty, bash versions prior
to bash-5.1 printed an informational message to that ef-
fect, even when producing output that can be reused as
input. Bash-5.1 suppresses that message when the --ll op-
tion is supplied.
ccoommppaatt5511
+o The uunnsseett builtin treats attempts to unset array sub-
scripts @@ and ** differently depending on whether the ar-
ray is indexed or associative, and differently than in
+o The uunnsseett builtin treats attempts to unset array sub-
scripts @@ and ** differently depending on whether the ar-
ray is indexed or associative, and differently than in
previous versions.
RREESSTTRRIICCTTEEDD SSHHEELLLL
If bbaasshh is started with the name rrbbaasshh, or the --rr 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 bbaasshh 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 bbaasshh with the exception that the following are
disallowed or not performed:
+o changing directories with ccdd
+o setting or unsetting the values of SSHHEELLLL, PPAATTHH, HHIISSTTFFIILLEE, EENNVV,
+o setting or unsetting the values of SSHHEELLLL, PPAATTHH, HHIISSTTFFIILLEE, EENNVV,
or BBAASSHH__EENNVV
+o specifying command names containing //
+o specifying a filename containing a // as an argument to the ..
+o specifying a filename containing a // as an argument to the ..
builtin command
+o specifying a filename containing a slash as an argument to the
+o specifying a filename containing a slash as an argument to the
hhiissttoorryy builtin command
+o specifying a filename containing a slash as an argument to the
+o specifying a filename containing a slash as an argument to the
--pp option to the hhaasshh builtin command
+o importing function definitions from the shell environment at
+o importing function definitions from the shell environment at
startup
+o parsing the value of SSHHEELLLLOOPPTTSS from the shell environment at
+o parsing the value of SSHHEELLLLOOPPTTSS from the shell environment at
startup
+o redirecting output using the >, >|, <>, >&, &>, and >> redirect-
@@ -6704,28 +6705,28 @@ RREESSTTRRIICCTTEEDD SSHHEELLLL
+o using the eexxeecc builtin command to replace the shell with another
command
+o adding or deleting builtin commands with the --ff and --dd options
+o adding or deleting builtin commands with the --ff and --dd options
to the eennaabbllee builtin command
+o using the eennaabbllee builtin command to enable disabled shell
+o using the eennaabbllee builtin command to enable disabled shell
builtins
+o specifying the --pp option to the ccoommmmaanndd builtin command
+o turning off restricted mode with sseett ++rr or sshhoopptt --uu rree--
+o turning off restricted mode with sseett ++rr or sshhoopptt --uu rree--
ssttrriicctteedd__sshheellll.
These restrictions are enforced after any startup files are read.
When a command that is found to be a shell script is executed (see CCOOMM--
MMAANNDD EEXXEECCUUTTIIOONN above), rrbbaasshh turns off any restrictions in the shell
MMAANNDD EEXXEECCUUTTIIOONN above), rrbbaasshh turns off any restrictions in the shell
spawned to execute the script.
SSEEEE AALLSSOO
_B_a_s_h _R_e_f_e_r_e_n_c_e _M_a_n_u_a_l, Brian Fox and Chet Ramey
_T_h_e _G_n_u _R_e_a_d_l_i_n_e _L_i_b_r_a_r_y, Brian Fox and Chet Ramey
_T_h_e _G_n_u _H_i_s_t_o_r_y _L_i_b_r_a_r_y, Brian Fox and Chet Ramey
_P_o_r_t_a_b_l_e _O_p_e_r_a_t_i_n_g _S_y_s_t_e_m _I_n_t_e_r_f_a_c_e _(_P_O_S_I_X_) _P_a_r_t _2_: _S_h_e_l_l _a_n_d _U_t_i_l_i_-
_P_o_r_t_a_b_l_e _O_p_e_r_a_t_i_n_g _S_y_s_t_e_m _I_n_t_e_r_f_a_c_e _(_P_O_S_I_X_) _P_a_r_t _2_: _S_h_e_l_l _a_n_d _U_t_i_l_i_-
_t_i_e_s, IEEE --
http://pubs.opengroup.org/onlinepubs/9699919799/
http://tiswww.case.edu/~chet/bash/POSIX -- a description of posix mode
@@ -6743,10 +6744,10 @@ FFIILLEESS
_~_/_._b_a_s_h_r_c
The individual per-interactive-shell startup file
_~_/_._b_a_s_h___l_o_g_o_u_t
The individual login shell cleanup file, executed when a login
The individual login shell cleanup file, executed when a login
shell exits
_~_/_._b_a_s_h___h_i_s_t_o_r_y
The default value of HHIISSTTFFIILLEE, the file in which bash saves the
The default value of HHIISSTTFFIILLEE, the file in which bash saves the
command history
_~_/_._i_n_p_u_t_r_c
Individual _r_e_a_d_l_i_n_e initialization file
@@ -6760,15 +6761,15 @@ AAUUTTHHOORRSS
BBUUGG RREEPPOORRTTSS
If you find a bug in bbaasshh,, 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 bbaasshh. The latest version is always available from
make sure that it really is a bug, and that it appears in the latest
version of bbaasshh. The latest version is always available from
_f_t_p_:_/_/_f_t_p_._g_n_u_._o_r_g_/_p_u_b_/_g_n_u_/_b_a_s_h_/ and _h_t_t_p_:_/_/_g_i_t_._s_a_v_a_n_-
_n_a_h_._g_n_u_._o_r_g_/_c_g_i_t_/_b_a_s_h_._g_i_t_/_s_n_a_p_s_h_o_t_/_b_a_s_h_-_m_a_s_t_e_r_._t_a_r_._g_z.
Once you have determined that a bug actually exists, use the _b_a_s_h_b_u_g
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 _b_u_g_-_b_a_s_h_@_g_n_u_._o_r_g or posted to the Usenet newsgroup
Once you have determined that a bug actually exists, use the _b_a_s_h_b_u_g
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 _b_u_g_-_b_a_s_h_@_g_n_u_._o_r_g or posted to the Usenet newsgroup
ggnnuu..bbaasshh..bbuugg.
ALL bug reports should include:
@@ -6779,7 +6780,7 @@ BBUUGG RREEPPOORRTTSS
A description of the bug behaviour
A short script or `recipe' which exercises the bug
_b_a_s_h_b_u_g inserts the first three items automatically into the template
_b_a_s_h_b_u_g 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
@@ -6796,10 +6797,10 @@ BBUUGGSS
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.
@@ -6808,4 +6809,4 @@ BBUUGGSS
GNU Bash 5.3 2023 July 19 BASH(1)
GNU Bash 5.3 2023 July 26 BASH(1)