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commit bash-20180316 snapshot

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Chet Ramey
2018-03-19 09:46:55 -04:00
parent bf5b8103d4
commit f602026a0c
59 changed files with 6880 additions and 6405 deletions
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@@ -457,24 +457,24 @@ SSHHEELLLL GGRRAAMMMMAARR
ccaassee _w_o_r_d iinn [ [(] _p_a_t_t_e_r_n [ || _p_a_t_t_e_r_n ] ... ) _l_i_s_t ;; ] ... eessaacc
A ccaassee command first expands _w_o_r_d, and tries to match it against
each _p_a_t_t_e_r_n in turn, using the same matching rules as for path-
name expansion (see PPaatthhnnaammee EExxppaannssiioonn below). The _w_o_r_d is
expanded using tilde expansion, parameter and variable expan-
sion, arithmetic expansion, command substitution, process sub-
stitution and quote removal. Each _p_a_t_t_e_r_n examined is expanded
using tilde expansion, parameter and variable expansion, arith-
metic expansion, command substitution, and process substitution.
If the nnooccaasseemmaattcchh shell option is enabled, the match is per-
formed without regard to the case of alphabetic characters.
When a match is found, the corresponding _l_i_s_t is executed. If
the ;;;; operator is used, no subsequent matches are attempted
after the first pattern match. Using ;;&& in place of ;;;; causes
execution to continue with the _l_i_s_t associated with the next set
of patterns. Using ;;;;&& in place of ;;;; causes the shell to test
the next pattern list in the statement, if any, and execute any
associated _l_i_s_t on a successful match. The exit status is zero
if no pattern matches. Otherwise, it is the exit status of the
last command executed in _l_i_s_t.
each _p_a_t_t_e_r_n in turn, using the matching rules described under
PPaatttteerrnn MMaattcchhiinngg below. The _w_o_r_d is expanded using tilde expan-
sion, parameter and variable expansion, arithmetic expansion,
command substitution, process substitution and quote removal.
Each _p_a_t_t_e_r_n examined is expanded using tilde expansion, parame-
ter and variable expansion, arithmetic expansion, command sub-
stitution, and process substitution. If the nnooccaasseemmaattcchh shell
option is enabled, the match is performed without regard to the
case of alphabetic characters. When a match is found, the cor-
responding _l_i_s_t is executed. If the ;;;; operator is used, no
subsequent matches are attempted after the first pattern match.
Using ;;&& in place of ;;;; causes execution to continue with the
_l_i_s_t associated with the next set of patterns. Using ;;;;&& in
place of ;;;; causes the shell to test the next pattern list in
the statement, if any, and execute any associated _l_i_s_t on a suc-
cessful match. The exit status is zero if no pattern matches.
Otherwise, it is the exit status of the last command executed in
_l_i_s_t.
iiff _l_i_s_t; tthheenn _l_i_s_t; [ eelliiff _l_i_s_t; tthheenn _l_i_s_t; ] ... [ eellssee _l_i_s_t; ] ffii
The iiff _l_i_s_t is executed. If its exit status is zero, the tthheenn
@@ -1710,100 +1710,105 @@ EEXXPPAANNSSIIOONN
${_p_a_r_a_m_e_t_e_r##_w_o_r_d}
${_p_a_r_a_m_e_t_e_r####_w_o_r_d}
RReemmoovvee mmaattcchhiinngg pprreeffiixx ppaatttteerrnn. The _w_o_r_d is expanded to produce
a pattern just as in pathname expansion. If the pattern matches
the beginning of the value of _p_a_r_a_m_e_t_e_r, then the result of the
a pattern just as in pathname expansion, and matched against the
expanded value of _p_a_r_a_m_e_t_e_r using the rules described under PPaatt--
tteerrnn MMaattcchhiinngg below. If the pattern matches the beginning of
the value of _p_a_r_a_m_e_t_e_r, then the result of the expansion is the
expanded value of _p_a_r_a_m_e_t_e_r with the shortest matching pattern
(the ``##'' case) or the longest matching pattern (the ``####''
case) deleted. If _p_a_r_a_m_e_t_e_r is @@ or **, the pattern removal
operation is applied to each positional parameter in turn, and
the expansion is the resultant list. If _p_a_r_a_m_e_t_e_r is an array
variable subscripted with @@ or **, the pattern removal operation
is applied to each member of the array in turn, and the expan-
sion is the resultant list.
${_p_a_r_a_m_e_t_e_r%%_w_o_r_d}
${_p_a_r_a_m_e_t_e_r%%%%_w_o_r_d}
RReemmoovvee mmaattcchhiinngg ssuuffffiixx ppaatttteerrnn. The _w_o_r_d is expanded to produce
a pattern just as in pathname expansion, and matched against the
expanded value of _p_a_r_a_m_e_t_e_r using the rules described under PPaatt--
tteerrnn MMaattcchhiinngg below. If the pattern matches a trailing portion
of the expanded value of _p_a_r_a_m_e_t_e_r, then the result of the
expansion is the expanded value of _p_a_r_a_m_e_t_e_r with the shortest
matching pattern (the ``##'' case) or the longest matching pat-
tern (the ``####'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@ or **, the
matching pattern (the ``%%'' case) or the longest matching pat-
tern (the ``%%%%'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@ or **, the
pattern removal operation is applied to each positional parame-
ter in turn, and the expansion is the resultant list. If _p_a_r_a_m_-
_e_t_e_r is an array variable subscripted with @@ or **, the pattern
removal operation is applied to each member of the array in
turn, and the expansion is the resultant list.
${_p_a_r_a_m_e_t_e_r%%_w_o_r_d}
${_p_a_r_a_m_e_t_e_r%%%%_w_o_r_d}
RReemmoovvee mmaattcchhiinngg ssuuffffiixx ppaatttteerrnn. The _w_o_r_d is expanded to produce
a pattern just as in pathname expansion. If the pattern matches
a trailing portion of the expanded value of _p_a_r_a_m_e_t_e_r, then the
result of the expansion is the expanded value of _p_a_r_a_m_e_t_e_r with
the shortest matching pattern (the ``%%'' case) or the longest
matching pattern (the ``%%%%'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@
or **, the pattern removal operation is applied to each posi-
tional parameter in turn, and the expansion is the resultant
list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted with @@ or
**, the pattern removal operation is applied to each member of
the array in turn, and the expansion is the resultant list.
${_p_a_r_a_m_e_t_e_r//_p_a_t_t_e_r_n//_s_t_r_i_n_g}
PPaatttteerrnn ssuubbssttiittuuttiioonn. The _p_a_t_t_e_r_n is expanded to produce a pat-
tern just as in pathname expansion. _P_a_r_a_m_e_t_e_r is expanded and
tern just as in pathname expansion, _P_a_r_a_m_e_t_e_r is expanded and
the longest match of _p_a_t_t_e_r_n against its value is replaced with
_s_t_r_i_n_g. If _p_a_t_t_e_r_n begins with //, all matches of _p_a_t_t_e_r_n are
replaced with _s_t_r_i_n_g. Normally only the first match is
replaced. If _p_a_t_t_e_r_n begins with ##, it must match at the begin-
ning of the expanded value of _p_a_r_a_m_e_t_e_r. If _p_a_t_t_e_r_n begins with
%%, it must match at the end of the expanded value of _p_a_r_a_m_e_t_e_r.
If _s_t_r_i_n_g is null, matches of _p_a_t_t_e_r_n are deleted and the // fol-
lowing _p_a_t_t_e_r_n may be omitted. If the nnooccaasseemmaattcchh shell option
is enabled, the match is performed without regard to the case of
alphabetic characters. If _p_a_r_a_m_e_t_e_r is @@ or **, the substitution
operation is applied to each positional parameter in turn, and
the expansion is the resultant list. If _p_a_r_a_m_e_t_e_r is an array
variable subscripted with @@ or **, the substitution operation is
applied to each member of the array in turn, and the expansion
is the resultant list.
_s_t_r_i_n_g. The match is performed using the rules described under
PPaatttteerrnn MMaattcchhiinngg below. If _p_a_t_t_e_r_n begins with //, all matches
of _p_a_t_t_e_r_n are replaced with _s_t_r_i_n_g. Normally only the first
match is replaced. If _p_a_t_t_e_r_n begins with ##, it must match at
the beginning of the expanded value of _p_a_r_a_m_e_t_e_r. If _p_a_t_t_e_r_n
begins with %%, it must match at the end of the expanded value of
_p_a_r_a_m_e_t_e_r. If _s_t_r_i_n_g is null, matches of _p_a_t_t_e_r_n are deleted
and the // following _p_a_t_t_e_r_n may be omitted. If the nnooccaasseemmaattcchh
shell option is enabled, the match is performed without regard
to the case of alphabetic characters. If _p_a_r_a_m_e_t_e_r is @@ or **,
the substitution operation is applied to each positional parame-
ter in turn, and the expansion is the resultant list. If _p_a_r_a_m_-
_e_t_e_r is an array variable subscripted with @@ or **, the substitu-
tion operation is applied to each member of the array in turn,
and the expansion is the resultant list.
${_p_a_r_a_m_e_t_e_r^^_p_a_t_t_e_r_n}
${_p_a_r_a_m_e_t_e_r^^^^_p_a_t_t_e_r_n}
${_p_a_r_a_m_e_t_e_r,,_p_a_t_t_e_r_n}
${_p_a_r_a_m_e_t_e_r,,,,_p_a_t_t_e_r_n}
CCaassee mmooddiiffiiccaattiioonn. This expansion modifies the case of alpha-
betic characters in _p_a_r_a_m_e_t_e_r. The _p_a_t_t_e_r_n is expanded to pro-
CCaassee mmooddiiffiiccaattiioonn. This expansion modifies the case of alpha-
betic characters in _p_a_r_a_m_e_t_e_r. The _p_a_t_t_e_r_n is expanded to pro-
duce a pattern just as in pathname expansion. Each character in
the expanded value of _p_a_r_a_m_e_t_e_r is tested against _p_a_t_t_e_r_n, and,
if it matches the pattern, its case is converted. The pattern
should not attempt to match more than one character. The ^^
operator converts lowercase letters matching _p_a_t_t_e_r_n to upper-
the expanded value of _p_a_r_a_m_e_t_e_r is tested against _p_a_t_t_e_r_n, and,
if it matches the pattern, its case is converted. The pattern
should not attempt to match more than one character. The ^^
operator converts lowercase letters matching _p_a_t_t_e_r_n to upper-
case; the ,, operator converts matching uppercase letters to low-
ercase. The ^^^^ and ,,,, expansions convert each matched character
in the expanded value; the ^^ and ,, expansions match and convert
only the first character in the expanded value. If _p_a_t_t_e_r_n is
omitted, it is treated like a ??, which matches every character.
If _p_a_r_a_m_e_t_e_r is @@ or **, the case modification operation is
applied to each positional parameter in turn, and the expansion
is the resultant list. If _p_a_r_a_m_e_t_e_r is an array variable sub-
in the expanded value; the ^^ and ,, expansions match and convert
only the first character in the expanded value. If _p_a_t_t_e_r_n is
omitted, it is treated like a ??, which matches every character.
If _p_a_r_a_m_e_t_e_r is @@ or **, the case modification operation is
applied to each positional parameter in turn, and the expansion
is the resultant list. If _p_a_r_a_m_e_t_e_r is an array variable sub-
scripted with @@ or **, the case modification operation is applied
to each member of the array in turn, and the expansion is the
to each member of the array in turn, and the expansion is the
resultant list.
${_p_a_r_a_m_e_t_e_r@@_o_p_e_r_a_t_o_r}
PPaarraammeetteerr ttrraannssffoorrmmaattiioonn. The expansion is either a transforma-
tion of the value of _p_a_r_a_m_e_t_e_r or information about _p_a_r_a_m_e_t_e_r
itself, depending on the value of _o_p_e_r_a_t_o_r. Each _o_p_e_r_a_t_o_r is a
tion of the value of _p_a_r_a_m_e_t_e_r or information about _p_a_r_a_m_e_t_e_r
itself, depending on the value of _o_p_e_r_a_t_o_r. Each _o_p_e_r_a_t_o_r is a
single letter:
QQ The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r
QQ The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r
quoted in a format that can be reused as input.
EE The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r
with backslash escape sequences expanded as with the
EE The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r
with backslash escape sequences expanded as with the
$$''......'' quoting mechanism.
PP The expansion is a string that is the result of expanding
the value of _p_a_r_a_m_e_t_e_r as if it were a prompt string (see
PPRROOMMPPTTIINNGG below).
AA The expansion is a string in the form of an assignment
statement or ddeeccllaarree command that, if evaluated, will
AA The expansion is a string in the form of an assignment
statement or ddeeccllaarree command that, if evaluated, will
recreate _p_a_r_a_m_e_t_e_r with its attributes and value.
aa The expansion is a string consisting of flag values rep-
aa The expansion is a string consisting of flag values rep-
resenting _p_a_r_a_m_e_t_e_r's attributes.
If _p_a_r_a_m_e_t_e_r is @@ or **, the operation is applied to each posi-
tional parameter in turn, and the expansion is the resultant
list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted with @@ or
If _p_a_r_a_m_e_t_e_r is @@ or **, the operation is applied to each posi-
tional parameter in turn, and the expansion is the resultant
list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted with @@ or
**, the operation is applied to each member of the array in turn,
and the expansion is the resultant list.
The result of the expansion is subject to word splitting and
The result of the expansion is subject to word splitting and
pathname expansion as described below.
CCoommmmaanndd SSuubbssttiittuuttiioonn
@@ -1817,106 +1822,109 @@ EEXXPPAANNSSIIOONN
BBaasshh performs the expansion by executing _c_o_m_m_a_n_d in a subshell environ-
ment and replacing the command substitution with the standard output of
the command, with any trailing newlines deleted. Embedded newlines are
not deleted, but they may be removed during word splitting. The com-
mand substitution $$((ccaatt _f_i_l_e)) can be replaced by the equivalent but
not deleted, but they may be removed during word splitting. The com-
mand substitution $$((ccaatt _f_i_l_e)) can be replaced by the equivalent but
faster $$((<< _f_i_l_e)).
When the old-style backquote form of substitution is used, backslash
retains its literal meaning except when followed by $$, ``, or \\. The
When the old-style backquote form of substitution is used, backslash
retains its literal meaning except when followed by $$, ``, or \\. The
first backquote not preceded by a backslash terminates the command sub-
stitution. When using the $(_c_o_m_m_a_n_d) form, all characters between the
stitution. When using the $(_c_o_m_m_a_n_d) form, all characters between the
parentheses make up the command; none are treated specially.
Command substitutions may be nested. To nest when using the backquoted
form, escape the inner backquotes with backslashes.
If the substitution appears within double quotes, word splitting and
If the substitution appears within double quotes, word splitting and
pathname expansion are not performed on the results.
AArriitthhmmeettiicc EExxppaannssiioonn
Arithmetic expansion allows the evaluation of an arithmetic expression
and the substitution of the result. The format for arithmetic expan-
Arithmetic expansion allows the evaluation of an arithmetic expression
and the substitution of the result. The format for arithmetic expan-
sion is:
$$((((_e_x_p_r_e_s_s_i_o_n))))
The _e_x_p_r_e_s_s_i_o_n is treated as if it were within double quotes, but a
double quote inside the parentheses is not treated specially. All
The _e_x_p_r_e_s_s_i_o_n is treated as if it were within double quotes, but a
double quote inside the parentheses is not treated specially. All
tokens in the expression undergo parameter and variable expansion, com-
mand substitution, and quote removal. The result is treated as the
arithmetic expression to be evaluated. Arithmetic expansions may be
mand substitution, and quote removal. The result is treated as the
arithmetic expression to be evaluated. Arithmetic expansions may be
nested.
The evaluation is performed according to the rules listed below under
The evaluation is performed according to the rules listed below under
AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. If _e_x_p_r_e_s_s_i_o_n is invalid, bbaasshh prints a message
indicating failure and no substitution occurs.
PPrroocceessss SSuubbssttiittuuttiioonn
_P_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n allows a process's input or output to be referred
to using a filename. It takes the form of <<((_l_i_s_t)) or >>((_l_i_s_t)). The
process _l_i_s_t is run asynchronously, and its input or output appears as
_P_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n allows a process's input or output to be referred
to using a filename. It takes the form of <<((_l_i_s_t)) or >>((_l_i_s_t)). The
process _l_i_s_t is run asynchronously, and its input or output appears as
a filename. This filename is passed as an argument to the current com-
mand as the result of the expansion. If the >>((_l_i_s_t)) form is used,
writing to the file will provide input for _l_i_s_t. If the <<((_l_i_s_t)) form
is used, the file passed as an argument should be read to obtain the
mand as the result of the expansion. If the >>((_l_i_s_t)) form is used,
writing to the file will provide input for _l_i_s_t. If the <<((_l_i_s_t)) form
is used, the file passed as an argument should be read to obtain the
output of _l_i_s_t. Process substitution is supported on systems that sup-
port named pipes (_F_I_F_O_s) or the //ddeevv//ffdd method of naming open files.
When available, process substitution is performed simultaneously with
parameter and variable expansion, command substitution, and arithmetic
When available, process substitution is performed simultaneously with
parameter and variable expansion, command substitution, and arithmetic
expansion.
WWoorrdd SSpplliittttiinngg
The shell scans the results of parameter expansion, command substitu-
tion, and arithmetic expansion that did not occur within double quotes
The shell scans the results of parameter expansion, command substitu-
tion, and arithmetic expansion that did not occur within double quotes
for _w_o_r_d _s_p_l_i_t_t_i_n_g.
The shell treats each character of IIFFSS as a delimiter, and splits the
results of the other expansions into words using these characters as
field terminators. If IIFFSS is unset, or its value is exactly
<<ssppaaccee>><<ttaabb>><<nneewwlliinnee>>, the default, then sequences of <<ssppaaccee>>, <<ttaabb>>,
and <<nneewwlliinnee>> at the beginning and end of the results of the previous
expansions are ignored, and any sequence of IIFFSS characters not at the
beginning or end serves to delimit words. If IIFFSS has a value other
than the default, then sequences of the whitespace characters ssppaaccee,
ttaabb, and nneewwlliinnee are ignored at the beginning and end of the word, as
long as the whitespace character is in the value of IIFFSS (an IIFFSS white-
space character). Any character in IIFFSS that is not IIFFSS whitespace,
The shell treats each character of IIFFSS as a delimiter, and splits the
results of the other expansions into words using these characters as
field terminators. If IIFFSS is unset, or its value is exactly
<<ssppaaccee>><<ttaabb>><<nneewwlliinnee>>, the default, then sequences of <<ssppaaccee>>, <<ttaabb>>,
and <<nneewwlliinnee>> at the beginning and end of the results of the previous
expansions are ignored, and any sequence of IIFFSS characters not at the
beginning or end serves to delimit words. If IIFFSS has a value other
than the default, then sequences of the whitespace characters ssppaaccee,
ttaabb, and nneewwlliinnee are ignored at the beginning and end of the word, as
long as the whitespace character is in the value of IIFFSS (an IIFFSS white-
space character). Any character in IIFFSS that is not IIFFSS whitespace,
along with any adjacent IIFFSS whitespace characters, delimits a field. A
sequence of IIFFSS whitespace characters is also treated as a delimiter.
sequence of IIFFSS whitespace characters is also treated as a delimiter.
If the value of IIFFSS is null, no word splitting occurs.
Explicit null arguments ("""" or '''') are retained and passed to commands
Explicit null arguments ("""" or '''') are retained and passed to commands
as empty strings. Unquoted implicit null arguments, resulting from the
expansion of parameters that have no values, are removed. If a parame-
ter with no value is expanded within double quotes, a null argument
results and is retained and passed to a command as an empty string.
When a quoted null argument appears as part of a word whose expansion
is non-null, the null argument is removed. That is, the word -d''
ter with no value is expanded within double quotes, a null argument
results and is retained and passed to a command as an empty string.
When a quoted null argument appears as part of a word whose expansion
is non-null, the null argument is removed. That is, the word -d''
becomes -d after word splitting and null argument removal.
Note that if no expansion occurs, no splitting is performed.
PPaatthhnnaammee EExxppaannssiioonn
After word splitting, unless the --ff option has been set, bbaasshh scans
each word for the characters **, ??, and [[. If one of these characters
appears, then the word is regarded as a _p_a_t_t_e_r_n, and replaced with an
alphabetically sorted list of filenames matching the pattern (see PPaatt--
tteerrnn MMaattcchhiinngg below). If no matching filenames are found, and the
shell option nnuullllgglloobb is not enabled, the word is left unchanged. If
the nnuullllgglloobb option is set, and no matches are found, the word is
removed. If the ffaaiillgglloobb shell option is set, and no matches are
After word splitting, unless the --ff option has been set, bbaasshh scans
each word for the characters **, ??, and [[. If one of these characters
appears, then the word is regarded as a _p_a_t_t_e_r_n, and replaced with an
alphabetically sorted list of filenames matching the pattern (see PPaatt--
tteerrnn MMaattcchhiinngg below). If no matching filenames are found, and the
shell option nnuullllgglloobb is not enabled, the word is left unchanged. If
the nnuullllgglloobb option is set, and no matches are found, the word is
removed. If the ffaaiillgglloobb shell option is set, and no matches are
found, an error message is printed and the command is not executed. If
the shell option nnooccaasseegglloobb is enabled, the match is performed without
regard to the case of alphabetic characters. When a pattern is used
for pathname expansion, the character ````..'''' at the start of a name or
immediately following a slash must be matched explicitly, unless the
shell option ddoottgglloobb is set. The filenames ````..'''' and ````....'''' must
always be matched explicitly, even if ddoottgglloobb is set. When matching a
pathname, the slash character must always be matched explicitly. In
other cases, the ````..'''' character is not treated specially. See the
description of sshhoopptt below under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS for a descrip-
tion of the nnooccaasseegglloobb, nnuullllgglloobb, ffaaiillgglloobb, and ddoottgglloobb shell options.
the shell option nnooccaasseegglloobb is enabled, the match is performed without
regard to the case of alphabetic characters. When a pattern is used
for pathname expansion, the character ````..'''' at the start of a name or
immediately following a slash must be matched explicitly, unless the
shell option ddoottgglloobb is set. The filenames ````..'''' and ````....'''' must
always be matched explicitly, even if ddoottgglloobb is set. In other cases,
the ````..'''' character is not treated specially. When matching a path-
name, the slash character must always be matched explicitly by a slash
in the pattern, but in other matching contexts it can be matched by a
special pattern character as described below under PPaatttteerrnn MMaattcchhiinngg.
See the description of sshhoopptt below under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS for a
description of the nnooccaasseegglloobb, nnuullllgglloobb, ffaaiillgglloobb, and ddoottgglloobb shell
options.
The GGLLOOBBIIGGNNOORREE shell variable may be used to restrict the set of file
names matching a _p_a_t_t_e_r_n. If GGLLOOBBIIGGNNOORREE is set, each matching file
@@ -6106,4 +6114,4 @@ BBUUGGSS
GNU Bash 4.4 2018 March 2 BASH(1)
GNU Bash 5.0 2018 March 15 BASH(1)