From c813e24652989e829c2af483d526fabbc1cc2223 Mon Sep 17 00:00:00 2001 From: Chet Ramey Date: Mon, 25 Oct 2021 11:56:15 -0400 Subject: [PATCH] new `patsub_replacement' shell option --- CWRU/CWRU.chlog | 10 + builtins/shopt.def | 3 + doc/bash.0 | 1357 +++++++++++++++++++++++--------------------- doc/bash.1 | 14 +- doc/bashref.info | 238 ++++---- doc/bashref.texi | 10 +- doc/version.texi | 4 +- tests/RUN-ONE-TEST | 2 +- tests/shopt.right | 2 + 9 files changed, 869 insertions(+), 771 deletions(-) diff --git a/CWRU/CWRU.chlog b/CWRU/CWRU.chlog index 83323392..7f87832d 100644 --- a/CWRU/CWRU.chlog +++ b/CWRU/CWRU.chlog @@ -2324,3 +2324,13 @@ doc/{bash.1,bashref.texi} and the shell receives a SIGINT while waiting for the foreground command to complete. Added at Red Hat's request. A complete discussion is at https://www.cons.org/cracauer/sigint.html + + 10/25 + ----- +builtins/shopt.def + - patsub_replacement: new shell option, exposes patsub_replacement + variable controlling whether pattern substitution expands `&' in + the replacement string. Still enabled by default. + +doc/{bash.1,bashref.texi} + - patsub_replacement: document new shopt option diff --git a/builtins/shopt.def b/builtins/shopt.def index d78f8d89..9dba27e3 100644 --- a/builtins/shopt.def +++ b/builtins/shopt.def @@ -95,6 +95,7 @@ extern int localvar_inherit; extern int localvar_unset; extern int varassign_redir_autoclose; extern int singlequote_translations; +extern int patsub_replacement; #if defined (EXTENDED_GLOB) extern int extended_glob; @@ -237,6 +238,7 @@ static struct { { "nocasematch", &match_ignore_case, (shopt_set_func_t *)NULL }, { "noexpand_translation", &singlequote_translations, (shopt_set_func_t *)NULL }, { "nullglob", &allow_null_glob_expansion, (shopt_set_func_t *)NULL }, + { "patsub_replacement", &patsub_replacement, (shopt_set_func_t *)NULL }, #if defined (PROGRAMMABLE_COMPLETION) { "progcomp", &prog_completion_enabled, (shopt_set_func_t *)NULL }, # if defined (ALIAS) @@ -363,6 +365,7 @@ reset_shopt_options () source_uses_path = promptvars = 1; varassign_redir_autoclose = 0; singlequote_translations = 0; + patsub_replacement = 1; #if defined (JOB_CONTROL) check_jobs_at_exit = 0; diff --git a/doc/bash.0 b/doc/bash.0 index 0a571f10..62ec3950 100644 --- a/doc/bash.0 +++ b/doc/bash.0 @@ -1846,90 +1846,91 @@ EEXXPPAANNSSIIOONN end of the expanded value of _p_a_r_a_m_e_t_e_r. If the expansion of _s_t_r_i_n_g is null, matches of _p_a_t_t_e_r_n are deleted. 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. Any unquoted instances of && in _s_t_r_i_n_g are re- - placed with the matching portion of _p_a_t_t_e_r_n. Backslash is used - to quote && in _s_t_r_i_n_g; the backslash is removed in order to per- - mit a literal && in the replacement string. Users should take - care if _s_t_r_i_n_g is double-quoted to avoid unwanted interactions - between the backslash and double-quoting. Pattern substitution - performs the check for && after expanding _s_t_r_i_n_g; shell program- - mers should quote backslashes intended to escape the && and in- + may be omitted. If the ppaattssuubb__rreeppllaacceemmeenntt shell option is en- + abled using sshhoopptt, any unquoted instances of && in _s_t_r_i_n_g are re- + placed with the matching portion of _p_a_t_t_e_r_n. Backslash is used + to quote && in _s_t_r_i_n_g; the backslash is removed in order to per- + mit a literal && in the replacement string. Users should take + care if _s_t_r_i_n_g is double-quoted to avoid unwanted interactions + between the backslash and double-quoting. Pattern substitution + performs the check for && after expanding _s_t_r_i_n_g; shell program- + mers should quote backslashes intended to escape the && and in- hibit replacement so they survive any quote removal performed by the expansion of _s_t_r_i_n_g. If the nnooccaasseemmaattcchh shell option is en- - abled, the match is performed without regard to the case of al- - phabetic 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 + abled, the match is performed without regard to the case of al- + phabetic 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. ${_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 ^^ op- + 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 ^^ op- erator converts lowercase letters matching _p_a_t_t_e_r_n to uppercase; the ,, operator converts matching uppercase letters to lowercase. - 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 omit- - ted, 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 subscripted - with @@ or **, the case modification operation is applied to each - member of the array in turn, and the expansion is the resultant + 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 omit- + ted, 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 subscripted + with @@ or **, the case modification 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@@_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: - UU The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r - with lowercase alphabetic characters converted to upper- + UU The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r + with lowercase alphabetic characters converted to upper- case. - uu The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r + uu The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r with the first character converted to uppercase, if it is alphabetic. - LL The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r - with uppercase alphabetic characters converted to lower- + LL The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r + with uppercase alphabetic characters converted to lower- case. - 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. KK Produces a possibly-quoted version of the value of _p_a_r_a_m_- _e_t_e_r, except that it prints the values of indexed and as- - sociative arrays as a sequence of quoted key-value pairs + sociative arrays as a sequence of quoted key-value pairs (see AArrrraayyss above). - 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. - kk Like the K transformation, but expands the keys and val- - ues of indexed and associative arrays to separate words + kk Like the K transformation, but expands the keys and val- + ues of indexed and associative arrays to separate words after word splitting. - 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 @@ -1943,121 +1944,121 @@ 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 undergoes the same expansions as if it were within dou- - ble quotes, but double quote characters in _e_x_p_r_e_s_s_i_o_n are not treated + The _e_x_p_r_e_s_s_i_o_n undergoes the same expansions as if it were within dou- + ble quotes, but double quote characters in _e_x_p_r_e_s_s_i_o_n are not treated specially and are removed. All tokens in the expression undergo param- - eter and variable expansion, command substitution, and quote removal. - The result is treated as the arithmetic expression to be evaluated. + eter and variable expansion, command 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 - <><><>, the default, then sequences of <>, <>, - and <> 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 + <><><>, the default, then sequences of <>, <>, + and <> 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 re- sults 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 + 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 + After word splitting, unless the --ff option has been set, bbaasshh scans + each word for the characters **, ??, and [[. If one of these characters appears, and is not quoted, 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 PPaatttteerrnn 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 + replaced with an alphabetically sorted list of filenames matching the + pattern (see PPaatttteerrnn 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 per- - formed 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 ex- - plicitly, unless the shell option ddoottgglloobb is set. In order to match + formed 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 ex- + plicitly, unless the shell option ddoottgglloobb is set. In order to match the filenames ````..'''' and ````....'''', the pattern must begin with ``.'' (for example, ``.?''), even if ddoottgglloobb is set. When not matching pathnames, - 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 + 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 - name that also matches one of the patterns in GGLLOOBBIIGGNNOORREE is removed - from the list of matches. If the nnooccaasseegglloobb option is set, the match- - ing against the patterns in GGLLOOBBIIGGNNOORREE is performed without regard to + 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 + name that also matches one of the patterns in GGLLOOBBIIGGNNOORREE is removed + from the list of matches. If the nnooccaasseegglloobb option is set, the match- + ing against the patterns in GGLLOOBBIIGGNNOORREE is performed without regard to case. The filenames ````..'''' and ````....'''' are always ignored when GGLLOOBBIIGG-- - NNOORREE is set and not null. However, setting GGLLOOBBIIGGNNOORREE to a non-null + NNOORREE is set and not null. However, setting GGLLOOBBIIGGNNOORREE to a non-null value has the effect of enabling the ddoottgglloobb shell option, so all other - filenames beginning with a ````..'''' will match. To get the old behavior - of ignoring filenames beginning with a ````..'''', make ````..**'''' one of the + filenames beginning with a ````..'''' will match. To get the old behavior + of ignoring filenames beginning with a ````..'''', make ````..**'''' one of the patterns in GGLLOOBBIIGGNNOORREE. The ddoottgglloobb option is disabled when GGLLOOBBIIGGNNOORREE is unset. The pattern matching honors the setting of the eexxttgglloobb shell option. @@ -2065,59 +2066,59 @@ EEXXPPAANNSSIIOONN PPaatttteerrnn MMaattcchhiinngg Any character that appears in a pattern, other than the special pattern - characters described below, matches itself. The NUL character may not - occur in a pattern. A backslash escapes the following character; the - escaping backslash is discarded when matching. The special pattern + characters described below, matches itself. The NUL character may not + occur in a pattern. A backslash escapes the following character; the + escaping backslash is discarded when matching. The special pattern characters must be quoted if they are to be matched literally. The special pattern characters have the following meanings: - ** Matches any string, including the null string. When the - gglloobbssttaarr shell option is enabled, and ** is used in a - pathname expansion context, two adjacent **s used as a - single pattern will match all files and zero or more di- - rectories and subdirectories. If followed by a //, two - adjacent **s will match only directories and subdirecto- + ** Matches any string, including the null string. When the + gglloobbssttaarr shell option is enabled, and ** is used in a + pathname expansion context, two adjacent **s used as a + single pattern will match all files and zero or more di- + rectories and subdirectories. If followed by a //, two + adjacent **s will match only directories and subdirecto- ries. ?? Matches any single character. - [[......]] Matches any one of the enclosed characters. A pair of - characters separated by a hyphen denotes a _r_a_n_g_e _e_x_p_r_e_s_- - _s_i_o_n; any character that falls between those two charac- + [[......]] Matches any one of the enclosed characters. A pair of + characters separated by a hyphen denotes a _r_a_n_g_e _e_x_p_r_e_s_- + _s_i_o_n; any character that falls between those two charac- ters, inclusive, using the current locale's collating se- quence and character set, is matched. If the first char- - acter following the [[ is a !! or a ^^ then any character + acter following the [[ is a !! or a ^^ then any character not enclosed is matched. The sorting order of characters - in range expressions is determined by the current locale - and the values of the LLCC__CCOOLLLLAATTEE or LLCC__AALLLL shell vari- - ables, if set. To obtain the traditional interpretation + in range expressions is determined by the current locale + and the values of the LLCC__CCOOLLLLAATTEE or LLCC__AALLLL shell vari- + ables, if set. To obtain the traditional interpretation of range expressions, where [[aa--dd]] is equivalent to - [[aabbccdd]], set value of the LLCC__AALLLL shell variable to CC, or - enable the gglloobbaasscciiiirraannggeess shell option. A -- may be + [[aabbccdd]], set value of the LLCC__AALLLL shell variable to CC, or + enable the gglloobbaasscciiiirraannggeess shell option. A -- may be matched by including it as the first or last character in the set. A ]] may be matched by including it as the first character in the set. - Within [[ and ]], _c_h_a_r_a_c_t_e_r _c_l_a_s_s_e_s can be specified using + Within [[ and ]], _c_h_a_r_a_c_t_e_r _c_l_a_s_s_e_s can be specified using the syntax [[::_c_l_a_s_s::]], where _c_l_a_s_s is one of the following classes defined in the POSIX standard: - aallnnuumm aallpphhaa aasscciiii bbllaannkk ccnnttrrll ddiiggiitt ggrraapphh lloowweerr pprriinntt + aallnnuumm aallpphhaa aasscciiii bbllaannkk ccnnttrrll ddiiggiitt ggrraapphh lloowweerr pprriinntt ppuunncctt ssppaaccee uuppppeerr wwoorrdd xxddiiggiitt A character class matches any character belonging to that class. The wwoorrdd character class matches letters, digits, and the character _. Within [[ and ]], an _e_q_u_i_v_a_l_e_n_c_e _c_l_a_s_s can be specified us- - ing the syntax [[==_c==]], which matches all characters with - the same collation weight (as defined by the current lo- + ing the syntax [[==_c==]], which matches all characters with + the same collation weight (as defined by the current lo- cale) as the character _c. Within [[ and ]], the syntax [[.._s_y_m_b_o_l..]] matches the collat- ing symbol _s_y_m_b_o_l. - If the eexxttgglloobb shell option is enabled using the sshhoopptt builtin, the - shell recognizes several extended pattern matching operators. In the + If the eexxttgglloobb shell option is enabled using the sshhoopptt builtin, the + shell recognizes several extended pattern matching operators. In the following description, a _p_a_t_t_e_r_n_-_l_i_s_t is a list of one or more patterns - separated by a ||. Composite patterns may be formed using one or more + separated by a ||. Composite patterns may be formed using one or more of the following sub-patterns: ??((_p_a_t_t_e_r_n_-_l_i_s_t)) @@ -2132,78 +2133,78 @@ EEXXPPAANNSSIIOONN Matches anything except one of the given patterns When matching filenames, the ddoottgglloobb shell option determines the set of - filenames that are tested: when ddoottgglloobb is enabled, the set of file- - names includes all files beginning with ``.'', but ``.'' and ``..'' - must be matched by a pattern or sub-pattern that begins with a dot; - when it is disabled, the set does not include any filenames beginning - with ``.'' unless the pattern or sub-pattern begins with a ``.''. As + filenames that are tested: when ddoottgglloobb is enabled, the set of file- + names includes all files beginning with ``.'', but ``.'' and ``..'' + must be matched by a pattern or sub-pattern that begins with a dot; + when it is disabled, the set does not include any filenames beginning + with ``.'' unless the pattern or sub-pattern begins with a ``.''. As above, ``.'' only has a special meaning when matching filenames. Complicated extended pattern matching against long strings is slow, es- pecially when the patterns contain alternations and the strings contain - multiple matches. Using separate matches against shorter strings, or + multiple matches. Using separate matches against shorter strings, or using arrays of strings instead of a single long string, may be faster. QQuuoottee RReemmoovvaall After the preceding expansions, all unquoted occurrences of the charac- - ters \\, '', and "" that did not result from one of the above expansions + ters \\, '', and "" that did not result from one of the above expansions are removed. RREEDDIIRREECCTTIIOONN - Before a command is executed, its input and output may be _r_e_d_i_r_e_c_t_e_d - using a special notation interpreted by the shell. _R_e_d_i_r_e_c_t_i_o_n allows - commands' file handles to be duplicated, opened, closed, made to refer + Before a command is executed, its input and output may be _r_e_d_i_r_e_c_t_e_d + using a special notation interpreted by the shell. _R_e_d_i_r_e_c_t_i_o_n allows + commands' file handles to be duplicated, opened, closed, made to refer to different files, and can change the files the command reads from and - writes to. Redirection may also be used to modify file handles in the - current shell execution environment. The following redirection opera- + writes to. Redirection may also be used to modify file handles in the + current shell execution environment. The following redirection opera- tors may precede or appear anywhere within a _s_i_m_p_l_e _c_o_m_m_a_n_d or may fol- - low a _c_o_m_m_a_n_d. Redirections are processed in the order they appear, + low a _c_o_m_m_a_n_d. Redirections are processed in the order they appear, from left to right. - Each redirection that may be preceded by a file descriptor number may + Each redirection that may be preceded by a file descriptor number may instead be preceded by a word of the form {_v_a_r_n_a_m_e}. In this case, for each redirection operator except >&- and <&-, the shell will allocate a - file descriptor greater than or equal to 10 and assign it to _v_a_r_n_a_m_e. - If >&- or <&- is preceded by {_v_a_r_n_a_m_e}, the value of _v_a_r_n_a_m_e defines - the file descriptor to close. If {_v_a_r_n_a_m_e} is supplied, the redirect- - ion persists beyond the scope of the command, allowing the shell pro- + file descriptor greater than or equal to 10 and assign it to _v_a_r_n_a_m_e. + If >&- or <&- is preceded by {_v_a_r_n_a_m_e}, the value of _v_a_r_n_a_m_e defines + the file descriptor to close. If {_v_a_r_n_a_m_e} is supplied, the redirect- + ion persists beyond the scope of the command, allowing the shell pro- grammer to manage the file descriptor's lifetime manually. The vvaarrrreeddiirr__cclloossee shell option manages this behavior. - In the following descriptions, if the file descriptor number is omit- - ted, and the first character of the redirection operator is <<, the re- - direction refers to the standard input (file descriptor 0). If the - first character of the redirection operator is >>, the redirection + In the following descriptions, if the file descriptor number is omit- + ted, and the first character of the redirection operator is <<, the re- + direction refers to the standard input (file descriptor 0). If the + first character of the redirection operator is >>, the redirection refers to the standard output (file descriptor 1). - The word following the redirection operator in the following descrip- - tions, unless otherwise noted, is subjected to brace expansion, tilde - expansion, parameter and variable expansion, command substitution, - arithmetic expansion, quote removal, pathname expansion, and word + The word following the redirection operator in the following descrip- + tions, unless otherwise noted, is subjected to brace expansion, tilde + expansion, parameter and variable expansion, command substitution, + arithmetic expansion, quote removal, pathname expansion, and word splitting. If it expands to more than one word, bbaasshh reports an error. - Note that the order of redirections is significant. For example, the + Note that the order of redirections is significant. For example, the command ls >> dirlist 2>>&&1 - directs both standard output and standard error to the file _d_i_r_l_i_s_t, + directs both standard output and standard error to the file _d_i_r_l_i_s_t, while the command ls 2>>&&1 >> dirlist - directs only the standard output to file _d_i_r_l_i_s_t, because the standard - error was duplicated from the standard output before the standard out- + directs only the standard output to file _d_i_r_l_i_s_t, because the standard + error was duplicated from the standard output before the standard out- put was redirected to _d_i_r_l_i_s_t. BBaasshh handles several filenames specially when they are used in redirec- tions, as described in the following table. If the operating system on which bbaasshh is running provides these special files, bash will use them; - otherwise it will emulate them internally with the behavior described + otherwise it will emulate them internally with the behavior described below. //ddeevv//ffdd//_f_d - If _f_d is a valid integer, file descriptor _f_d is dupli- + If _f_d is a valid integer, file descriptor _f_d is dupli- cated. //ddeevv//ssttddiinn File descriptor 0 is duplicated. @@ -2213,22 +2214,22 @@ RREEDDIIRREECCTTIIOONN File descriptor 2 is duplicated. //ddeevv//ttccpp//_h_o_s_t//_p_o_r_t If _h_o_s_t is a valid hostname or Internet address, and _p_o_r_t - is an integer port number or service name, bbaasshh attempts + is an integer port number or service name, bbaasshh attempts to open the corresponding TCP socket. //ddeevv//uuddpp//_h_o_s_t//_p_o_r_t If _h_o_s_t is a valid hostname or Internet address, and _p_o_r_t - is an integer port number or service name, bbaasshh attempts + is an integer port number or service name, bbaasshh attempts to open the corresponding UDP socket. A failure to open or create a file causes the redirection to fail. - Redirections using file descriptors greater than 9 should be used with - care, as they may conflict with file descriptors the shell uses inter- + Redirections using file descriptors greater than 9 should be used with + care, as they may conflict with file descriptors the shell uses inter- nally. RReeddiirreeccttiinngg IInnppuutt Redirection of input causes the file whose name results from the expan- - sion of _w_o_r_d to be opened for reading on file descriptor _n, or the + sion of _w_o_r_d to be opened for reading on file descriptor _n, or the standard input (file descriptor 0) if _n is not specified. The general format for redirecting input is: @@ -2236,27 +2237,27 @@ RREEDDIIRREECCTTIIOONN [_n]<<_w_o_r_d RReeddiirreeccttiinngg OOuuttppuutt - Redirection of output causes the file whose name results from the ex- - pansion of _w_o_r_d to be opened for writing on file descriptor _n, or the + Redirection of output causes the file whose name results from the ex- + pansion of _w_o_r_d to be opened for writing on file descriptor _n, or the standard output (file descriptor 1) if _n is not specified. If the file - does not exist it is created; if it does exist it is truncated to zero + does not exist it is created; if it does exist it is truncated to zero size. The general format for redirecting output is: [_n]>>_w_o_r_d - If the redirection operator is >>, and the nnoocclloobbbbeerr option to the sseett - builtin has been enabled, the redirection will fail if the file whose - name results from the expansion of _w_o_r_d exists and is a regular file. + If the redirection operator is >>, and the nnoocclloobbbbeerr option to the sseett + builtin has been enabled, the redirection will fail if the file whose + name results from the expansion of _w_o_r_d exists and is a regular file. If the redirection operator is >>||, or the redirection operator is >> and the nnoocclloobbbbeerr option to the sseett builtin command is not enabled, the re- direction is attempted even if the file named by _w_o_r_d exists. AAppppeennddiinngg RReeddiirreecctteedd OOuuttppuutt - Redirection of output in this fashion causes the file whose name re- + Redirection of output in this fashion causes the file whose name re- sults from the expansion of _w_o_r_d to be opened for appending on file de- - scriptor _n, or the standard output (file descriptor 1) if _n is not + scriptor _n, or the standard output (file descriptor 1) if _n is not specified. If the file does not exist it is created. The general format for appending output is: @@ -2264,11 +2265,11 @@ RREEDDIIRREECCTTIIOONN [_n]>>>>_w_o_r_d RReeddiirreeccttiinngg SSttaannddaarrdd OOuuttppuutt aanndd SSttaannddaarrdd EErrrroorr - This construct allows both the standard output (file descriptor 1) and - the standard error output (file descriptor 2) to be redirected to the + This construct allows both the standard output (file descriptor 1) and + the standard error output (file descriptor 2) to be redirected to the file whose name is the expansion of _w_o_r_d. - There are two formats for redirecting standard output and standard er- + There are two formats for redirecting standard output and standard er- ror: &&>>_w_o_r_d @@ -2280,13 +2281,13 @@ RREEDDIIRREECCTTIIOONN >>_w_o_r_d 2>>&&1 - When using the second form, _w_o_r_d may not expand to a number or --. If - it does, other redirection operators apply (see DDuupplliiccaattiinngg FFiillee DDee-- + When using the second form, _w_o_r_d may not expand to a number or --. If + it does, other redirection operators apply (see DDuupplliiccaattiinngg FFiillee DDee-- ssccrriippttoorrss below) for compatibility reasons. AAppppeennddiinngg SSttaannddaarrdd OOuuttppuutt aanndd SSttaannddaarrdd EErrrroorr - This construct allows both the standard output (file descriptor 1) and - the standard error output (file descriptor 2) to be appended to the + This construct allows both the standard output (file descriptor 1) and + the standard error output (file descriptor 2) to be appended to the file whose name is the expansion of _w_o_r_d. The format for appending standard output and standard error is: @@ -2300,10 +2301,10 @@ RREEDDIIRREECCTTIIOONN (see DDuupplliiccaattiinngg FFiillee DDeessccrriippttoorrss below). HHeerree DDooccuummeennttss - This type of redirection instructs the shell to read input from the + This type of redirection instructs the shell to read input from the current source until a line containing only _d_e_l_i_m_i_t_e_r (with no trailing - blanks) is seen. All of the lines read up to that point are then used - as the standard input (or file descriptor _n if _n is specified) for a + blanks) is seen. All of the lines read up to that point are then used + as the standard input (or file descriptor _n if _n is specified) for a command. The format of here-documents is: @@ -2312,18 +2313,18 @@ RREEDDIIRREECCTTIIOONN _h_e_r_e_-_d_o_c_u_m_e_n_t _d_e_l_i_m_i_t_e_r - No parameter and variable expansion, command substitution, arithmetic - expansion, or pathname expansion is performed on _w_o_r_d. If any part of - _w_o_r_d is quoted, the _d_e_l_i_m_i_t_e_r is the result of quote removal on _w_o_r_d, - and the lines in the here-document are not expanded. If _w_o_r_d is un- - quoted, all lines of the here-document are subjected to parameter ex- - pansion, command substitution, and arithmetic expansion, the character + No parameter and variable expansion, command substitution, arithmetic + expansion, or pathname expansion is performed on _w_o_r_d. If any part of + _w_o_r_d is quoted, the _d_e_l_i_m_i_t_e_r is the result of quote removal on _w_o_r_d, + and the lines in the here-document are not expanded. If _w_o_r_d is un- + quoted, all lines of the here-document are subjected to parameter ex- + pansion, command substitution, and arithmetic expansion, the character sequence \\<> is ignored, and \\ must be used to quote the charac- ters \\, $$, and ``. If the redirection operator is <<<<--, then all leading tab characters are - stripped from input lines and the line containing _d_e_l_i_m_i_t_e_r. This al- - lows here-documents within shell scripts to be indented in a natural + stripped from input lines and the line containing _d_e_l_i_m_i_t_e_r. This al- + lows here-documents within shell scripts to be indented in a natural fashion. HHeerree SSttrriinnggss @@ -2331,9 +2332,9 @@ RREEDDIIRREECCTTIIOONN [_n]<<<<<<_w_o_r_d - 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 + 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). @@ -2343,8 +2344,8 @@ 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 de- + 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 de- scriptor open for input, a redirection error occurs. If _w_o_r_d evaluates to --, file descriptor _n is closed. If _n is not specified, the standard input (file descriptor 0) is used. @@ -2353,12 +2354,12 @@ RREEDDIIRREECCTTIIOONN [_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 @@ -2366,7 +2367,7 @@ 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. @@ -2374,7 +2375,7 @@ 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 @@ -2382,144 +2383,144 @@ 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 + There is no mechanism for using arguments in the replacement text. If arguments are needed, use a shell function (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, and - all lines that make up a compound command, before executing any of the - commands on that line or the compound command. 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 command. As a - consequence, aliases defined in a function are not available until af- - ter that function is executed. To be safe, always put alias defini- + The rules concerning the definition and use of aliases are somewhat + confusing. BBaasshh always reads at least one complete line of input, and + all lines that make up a compound command, before executing any of the + commands on that line or the compound command. 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 command. As a + consequence, aliases defined in a function are not available until af- + ter that function is executed. To be safe, always put alias defini- tions 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 in- - terpret 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 in- + terpret 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 be- - tween 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 be- + tween 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. If a variable is declared llooccaall, the vari- - able's visible scope is restricted to that function and its children + 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 + 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 + 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 + 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 uunnsseett builtin also acts using the same dynamic scope: if a variable is local to the current scope, uunnsseett will unset it; otherwise the unset - will refer to the variable found in any calling scope as described - above. If a variable at the current local scope is unset, it will re- - main so until it is reset in that scope or until the function returns. - Once the function returns, any instance of the variable at a previous + will refer to the variable found in any calling scope as described + above. If a variable at the current local scope is unset, it will re- + main so until it is reset in that scope or until the function returns. + Once the function returns, any instance of the variable at a previous scope will become visible. If the unset acts on a variable at a previ- - ous scope, any instance of a variable with that name that had been + ous scope, any instance of a variable with that name that had been shadowed will become visible. - The FFUUNNCCNNEESSTT variable, if set to a numeric value greater than 0, de- - fines a maximum function nesting level. Function invocations that ex- + The FFUUNNCCNNEESSTT variable, if set to a numeric value greater than 0, de- + fines a maximum function nesting level. Function invocations that ex- ceed the limit cause the entire command to abort. - If the builtin command rreettuurrnn is executed in a function, the function - completes and execution resumes with the next command after the func- + If the builtin command rreettuurrnn is executed in a function, the function + completes and execution resumes with the next command after the func- tion call. Any command associated with the RREETTUURRNN trap is executed be- - fore execution resumes. When a function completes, the values of the - positional parameters and the special parameter ## are restored to the + fore execution resumes. When a function completes, the values of the + positional parameters and the special parameter ## are restored to the values they had prior to the function's execution. - Function names and definitions may be listed with the --ff option to the + Function names and definitions may be listed with the --ff option to the ddeeccllaarree or ttyyppeesseett builtin commands. The --FF option to ddeeccllaarree or ttyyppee-- - sseett will list the function names only (and optionally the source file - and line number, if the eexxttddeebbuugg shell option is enabled). Functions - may be exported so that child shell processes (those created when exe- - cuting a separate shell invocation) automatically have them defined + sseett will list the function names only (and optionally the source file + and line number, if the eexxttddeebbuugg shell option is enabled). Functions + may be exported so that child shell processes (those created when exe- + cuting a separate shell invocation) automatically have them defined with the --ff option to the eexxppoorrtt builtin. A function definition may be deleted using the --ff option to the uunnsseett builtin. Functions may be recursive. The FFUUNNCCNNEESSTT variable may be used to limit - the depth of the function call stack and restrict the number of func- + the depth of the function call stack and restrict the number of func- tion invocations. By default, no limit is imposed on the number of re- cursive calls. AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN - The shell allows arithmetic expressions to be evaluated, under certain - circumstances (see the lleett and ddeeccllaarree builtin commands, the (((( com- + The shell allows arithmetic expressions to be evaluated, under certain + circumstances (see the lleett and ddeeccllaarree builtin commands, the (((( com- pound command, and AArriitthhmmeettiicc EExxppaannssiioonn). Evaluation is done in fixed- - width integers with no check for overflow, though division by 0 is - trapped and flagged as an error. The operators and their precedence, - associativity, and values are the same as in the C language. The fol- + width integers with no check for overflow, though division by 0 is + trapped and flagged as an error. The operators and their precedence, + associativity, and values are the same as in the C language. The fol- lowing list of operators is grouped into levels of equal-precedence op- erators. The levels are listed in order of decreasing precedence. @@ -2548,55 +2549,55 @@ AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN _e_x_p_r_1 ,, _e_x_p_r_2 comma - Shell variables are allowed as operands; parameter expansion is per- + Shell variables are allowed as operands; parameter expansion is per- formed before the expression is evaluated. Within an expression, shell - variables may also be referenced by name without using the parameter - expansion syntax. A shell variable that is null or unset evaluates to + variables may also be referenced by name without using the parameter + expansion syntax. A shell variable that is null or unset evaluates to 0 when referenced by name without using the parameter expansion syntax. - The value of a variable is evaluated as an arithmetic expression when - it is referenced, or when a variable which has been given the _i_n_t_e_g_e_r + The value of a variable is evaluated as an arithmetic expression when + it is referenced, or when a variable which has been given the _i_n_t_e_g_e_r attribute using ddeeccllaarree --ii is assigned a value. A null value evaluates - to 0. A shell variable need not have its _i_n_t_e_g_e_r attribute turned on + to 0. A shell variable need not have its _i_n_t_e_g_e_r attribute turned on to be used in an expression. Integer constants follow the C language definition, without suffixes or character constants. Constants with a leading 0 are interpreted as oc- - tal numbers. A leading 0x or 0X denotes hexadecimal. Otherwise, num- - bers take the form [_b_a_s_e_#]n, where the optional _b_a_s_e is a decimal num- - ber between 2 and 64 representing the arithmetic base, and _n is a num- - ber in that base. If _b_a_s_e_# is omitted, then base 10 is used. When + tal numbers. A leading 0x or 0X denotes hexadecimal. Otherwise, num- + bers take the form [_b_a_s_e_#]n, where the optional _b_a_s_e is a decimal num- + ber between 2 and 64 representing the arithmetic base, and _n is a num- + ber in that base. If _b_a_s_e_# is omitted, then base 10 is used. When specifying _n, if a non-digit is required, the digits greater than 9 are - represented by the lowercase letters, the uppercase letters, @, and _, - in that order. If _b_a_s_e is less than or equal to 36, lowercase and up- - percase letters may be used interchangeably to represent numbers be- + represented by the lowercase letters, the uppercase letters, @, and _, + in that order. If _b_a_s_e is less than or equal to 36, lowercase and up- + percase letters may be used interchangeably to represent numbers be- tween 10 and 35. - Operators are evaluated in order of precedence. Sub-expressions in - parentheses are evaluated first and may override the precedence rules + Operators are evaluated in order of precedence. Sub-expressions in + parentheses are evaluated first and may override the precedence rules above. CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS - Conditional expressions are used by the [[[[ compound command and the - tteesstt and [[ builtin commands to test file attributes and perform string - and arithmetic comparisons. The tteesstt and [[ commands determine their - behavior based on the number of arguments; see the descriptions of + Conditional expressions are used by the [[[[ compound command and the + tteesstt and [[ builtin commands to test file attributes and perform string + and arithmetic comparisons. The tteesstt and [[ commands determine their + behavior based on the number of arguments; see the descriptions of those commands for any other command-specific actions. - Expressions are formed from the following unary or binary primaries. - BBaasshh handles several filenames specially when they are used in expres- + Expressions are formed from the following unary or binary primaries. + BBaasshh handles several filenames specially when they are used in expres- sions. If the operating system on which bbaasshh is running provides these - special files, bash will use them; otherwise it will emulate them in- - ternally with this behavior: If any _f_i_l_e argument to one of the pri- + special files, bash will use them; otherwise it will emulate them in- + ternally with this behavior: If any _f_i_l_e argument to one of the pri- maries is of the form _/_d_e_v_/_f_d_/_n, then file descriptor _n is checked. If - the _f_i_l_e argument to one of the primaries is one of _/_d_e_v_/_s_t_d_i_n, - _/_d_e_v_/_s_t_d_o_u_t, or _/_d_e_v_/_s_t_d_e_r_r, file descriptor 0, 1, or 2, respectively, + the _f_i_l_e argument to one of the primaries is one of _/_d_e_v_/_s_t_d_i_n, + _/_d_e_v_/_s_t_d_o_u_t, or _/_d_e_v_/_s_t_d_e_r_r, file descriptor 0, 1, or 2, respectively, is checked. Unless otherwise specified, primaries that operate on files follow sym- bolic links and operate on the target of the link, rather than the link itself. - When used with [[[[, the << and >> operators sort lexicographically using + When used with [[[[, the << and >> operators sort lexicographically using the current locale. The tteesstt command sorts using ASCII ordering. --aa _f_i_l_e @@ -2635,30 +2636,30 @@ CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS --LL _f_i_l_e True if _f_i_l_e exists and is a symbolic link. --NN _f_i_l_e - True if _f_i_l_e exists and has been modified since it was last + True if _f_i_l_e exists and has been modified since it was last read. --OO _f_i_l_e True if _f_i_l_e exists and is owned by the effective user id. --SS _f_i_l_e True if _f_i_l_e exists and is a socket. _f_i_l_e_1 --eeff _f_i_l_e_2 - True if _f_i_l_e_1 and _f_i_l_e_2 refer to the same device and inode num- + True if _f_i_l_e_1 and _f_i_l_e_2 refer to the same device and inode num- bers. _f_i_l_e_1 -nntt _f_i_l_e_2 - True if _f_i_l_e_1 is newer (according to modification date) than + True if _f_i_l_e_1 is newer (according to modification date) than _f_i_l_e_2, or if _f_i_l_e_1 exists and _f_i_l_e_2 does not. _f_i_l_e_1 -oott _f_i_l_e_2 - True if _f_i_l_e_1 is older than _f_i_l_e_2, or if _f_i_l_e_2 exists and _f_i_l_e_1 + True if _f_i_l_e_1 is older than _f_i_l_e_2, or if _f_i_l_e_2 exists and _f_i_l_e_1 does not. --oo _o_p_t_n_a_m_e - True if the shell option _o_p_t_n_a_m_e is enabled. See the list of - options under the description of the --oo option to the sseett + True if the shell option _o_p_t_n_a_m_e is enabled. See the list of + options under the description of the --oo option to the sseett builtin below. --vv _v_a_r_n_a_m_e - True if the shell variable _v_a_r_n_a_m_e is set (has been assigned a + True if the shell variable _v_a_r_n_a_m_e is set (has been assigned a value). --RR _v_a_r_n_a_m_e - True if the shell variable _v_a_r_n_a_m_e is set and is a name refer- + True if the shell variable _v_a_r_n_a_m_e is set and is a name refer- ence. --zz _s_t_r_i_n_g True if the length of _s_t_r_i_n_g is zero. @@ -2668,8 +2669,8 @@ CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS _s_t_r_i_n_g_1 ==== _s_t_r_i_n_g_2 _s_t_r_i_n_g_1 == _s_t_r_i_n_g_2 - True if the strings are equal. == should be used with the tteesstt - command for POSIX conformance. When used with the [[[[ command, + True if the strings are equal. == should be used with the tteesstt + command for POSIX conformance. When used with the [[[[ command, this performs pattern matching as described above (CCoommppoouunndd CCoomm-- mmaannddss). @@ -2683,113 +2684,113 @@ CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS True if _s_t_r_i_n_g_1 sorts after _s_t_r_i_n_g_2 lexicographically. _a_r_g_1 OOPP _a_r_g_2 - OOPP is one of --eeqq, --nnee, --lltt, --llee, --ggtt, or --ggee. These arithmetic - 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. When used with the [[[[ command, _A_r_g_1 and - _A_r_g_2 are evaluated as arithmetic expressions (see AARRIITTHHMMEETTIICC + OOPP is one of --eeqq, --nnee, --lltt, --llee, --ggtt, or --ggee. These arithmetic + 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. 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 ex- - pansions, assignments, and redirections, from left to right, in the + pansions, assignments, and redirections, from left to right, in the following order. - 1. The words that the parser has marked as variable assignments - (those preceding the command name) and redirections are saved + 1. The words that the parser has marked as variable assignments + (those preceding the command name) and redirections are saved for later processing. - 2. The words that are not variable assignments or redirections are - expanded. If any words remain after expansion, the first word - is taken to be the name of the command and the remaining words + 2. The words that are not variable assignments or redirections are + expanded. If any words remain after expansion, the first word + is taken to be the name of the command and the remaining words are the arguments. 3. Redirections are performed as described above under RREEDDIIRREECCTTIIOONN. 4. The text after the == in each variable assignment undergoes tilde expansion, parameter expansion, command substitution, arithmetic - expansion, and quote removal before being assigned to the vari- + expansion, and quote removal before being assigned to the vari- able. If no command name results, the variable assignments affect the current - shell environment. In the case of such a command (one that consists - only of assignment statements and redirections), assignment statements - are performed before redirections. Otherwise, the variables are added - to the environment of the executed command and do not affect the cur- + shell environment. In the case of such a command (one that consists + only of assignment statements and redirections), assignment statements + are performed before redirections. Otherwise, the variables are added + to the environment of the executed command and do not affect the cur- rent shell environment. If any of the assignments attempts to assign a - value to a readonly variable, an error occurs, and the command exits + value to a readonly variable, an error occurs, and the command exits with a non-zero status. - If no command name results, redirections are performed, but do not af- - fect the current shell environment. A redirection error causes the + If no command name results, redirections are performed, but do not af- + fect the current shell environment. A redirection error causes the command to exit with a non-zero status. - If there is a command name left after expansion, execution proceeds as - described below. Otherwise, the command exits. If one of the expan- - sions contained a command substitution, the exit status of the command - is the exit status of the last command substitution performed. If + If there is a command name left after expansion, execution proceeds as + described below. Otherwise, the command exits. If one of the expan- + sions contained a command substitution, the exit status of the command + is the exit status of the last command substitution performed. If there were no command substitutions, the command exits with a status of zero. CCOOMMMMAANNDD EEXXEECCUUTTIIOONN - After a command has been split into words, if it results in a simple - command and an optional list of arguments, the following actions are + After a command has been split into words, if it results in a simple + command and an optional list of arguments, the following actions are taken. - If the command name contains no slashes, the shell attempts to locate - it. If there exists a shell function by that name, that function is - invoked as described above in FFUUNNCCTTIIOONNSS. If the name does not match a - function, the shell searches for it in the list of shell builtins. If + If the command name contains no slashes, the shell attempts to locate + it. If there exists a shell function by that name, that function is + invoked as described above in FFUUNNCCTTIIOONNSS. If the name does not match a + function, the shell searches for it in the list of shell builtins. If a match is found, that builtin is invoked. - If the name is neither a shell function nor a builtin, and contains no - slashes, bbaasshh searches each element of the PPAATTHH for a directory con- + If the name is neither a shell function nor a builtin, and contains no + slashes, bbaasshh searches each element of the PPAATTHH for a directory con- taining an executable file by that name. BBaasshh uses a hash table to re- - member the full pathnames of executable files (see hhaasshh under SSHHEELLLL - BBUUIILLTTIINN CCOOMMMMAANNDDSS below). A full search of the directories in PPAATTHH is - performed only if the command is not found in the hash table. If the + member the full pathnames of executable files (see hhaasshh under SSHHEELLLL + BBUUIILLTTIINN CCOOMMMMAANNDDSS below). A full search of the directories in PPAATTHH is + performed only if the command is not found in the hash table. If the search is unsuccessful, the shell searches for a defined shell function named ccoommmmaanndd__nnoott__ffoouunndd__hhaannddllee. If that function exists, it is invoked - in a separate execution environment with the original command and the - original command's arguments as its arguments, and the function's exit - status becomes the exit status of that subshell. If that function is + in a separate execution environment with the original command and the + original command's arguments as its arguments, and the function's exit + status becomes the exit status of that subshell. If that function is not defined, the shell prints an error message and returns an exit sta- tus of 127. - If the search is successful, or if the command name contains one or + If the search is successful, or if the command name contains one or more slashes, the shell executes the named program in a separate execu- tion environment. Argument 0 is set to the name given, and the remain- ing arguments to the command are set to the arguments given, if any. - If this execution fails because the file is not in executable format, - and the file is not a directory, it is assumed to be a _s_h_e_l_l _s_c_r_i_p_t, a + If this execution fails because the file is not in executable format, + and the file is not a directory, it is assumed to be a _s_h_e_l_l _s_c_r_i_p_t, a file containing shell commands, and the shell creates a new instance of - itself to execute it. This subshell reinitializes itself, so that the + itself to execute it. This subshell reinitializes itself, so that the effect is as if a new shell had been invoked to handle the script, with - the exception that the locations of commands remembered by the parent - (see hhaasshh below under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS) are retained by the + the exception that the locations of commands remembered by the parent + (see hhaasshh below under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS) are retained by the child. - If the program is a file beginning with ##!!, the remainder of the first - line specifies an interpreter for the program. The shell executes the + If the program is a file beginning with ##!!, the remainder of the first + line specifies an interpreter for the program. The shell executes the specified interpreter on operating systems that do not handle this exe- cutable format themselves. The arguments to the interpreter consist of - a single optional argument following the interpreter name on the first - line of the program, followed by the name of the program, followed by + a single optional argument following the interpreter name on the first + line of the program, followed by the name of the program, followed by the command arguments, if any. CCOOMMMMAANNDD EEXXEECCUUTTIIOONN EENNVVIIRROONNMMEENNTT - The shell has an _e_x_e_c_u_t_i_o_n _e_n_v_i_r_o_n_m_e_n_t, which consists of the follow- + The shell has an _e_x_e_c_u_t_i_o_n _e_n_v_i_r_o_n_m_e_n_t, which consists of the follow- ing: - +o open files inherited by the shell at invocation, as modified by + +o open files inherited by the shell at invocation, as modified by redirections supplied to the eexxeecc builtin - +o the current working directory as set by ccdd, ppuusshhdd, or ppooppdd, or + +o the current working directory as set by ccdd, ppuusshhdd, or ppooppdd, or inherited by the shell at invocation - +o the file creation mode mask as set by uummaasskk or inherited from + +o the file creation mode mask as set by uummaasskk or inherited from the shell's parent +o current traps set by ttrraapp @@ -2797,154 +2798,179 @@ CCOOMMMMAANNDD EEXXEECCUUTTIIOONN EENNVVIIRROONNMMEENN +o shell parameters that are set by variable assignment or with sseett or inherited from the shell's parent in the environment - +o shell functions defined during execution or inherited from the + +o shell functions defined during execution or inherited from the shell's parent in the environment - +o options enabled at invocation (either by default or with com- + +o options enabled at invocation (either by default or with com- mand-line arguments) or by sseett +o options enabled by sshhoopptt +o shell aliases defined with aalliiaass - +o various process IDs, including those of background jobs, the + +o various process IDs, including those of background jobs, the value of $$$$, and the value of PPPPIIDD - When a simple command other than a builtin or shell function is to be - executed, it is invoked in a separate execution environment that con- - sists of the following. Unless otherwise noted, the values are inher- + When a simple command other than a builtin or shell function is to be + executed, it is invoked in a separate execution environment that con- + sists of the following. Unless otherwise noted, the values are inher- ited from the shell. - +o the shell's open files, plus any modifications and additions + +o the shell's open files, plus any modifications and additions specified by redirections to the command +o the current working directory +o the file creation mode mask - +o shell variables and functions marked for export, along with + +o shell variables and functions marked for export, along with variables exported for the command, passed in the environment +o traps caught by the shell are reset to the values inherited from the shell's parent, and traps ignored by the shell are ignored - A command invoked in this separate environment cannot affect the + A command invoked in this separate environment cannot affect the shell's execution environment. A _s_u_b_s_h_e_l_l is a copy of the shell process. - Command substitution, commands grouped with parentheses, and asynchro- + Command substitution, commands grouped with parentheses, and asynchro- nous commands are invoked in a subshell environment that is a duplicate of the shell environment, except that traps caught by the shell are re- - set to the values that the shell inherited from its parent at invoca- + set to the values that the shell inherited from its parent at invoca- tion. Builtin commands that are invoked as part of a pipeline are also executed in a subshell environment. Changes made to the subshell envi- ronment cannot affect the shell's execution environment. Subshells spawned to execute command substitutions inherit the value of - the --ee option from the parent shell. When not in _p_o_s_i_x _m_o_d_e, bbaasshh + the --ee option from the parent shell. When not in _p_o_s_i_x _m_o_d_e, bbaasshh clears the --ee option in such subshells. - If a command is followed by a && and job control is not active, the de- + If a command is followed by a && and job control is not active, the de- fault standard input for the command is the empty file _/_d_e_v_/_n_u_l_l. Oth- - erwise, the invoked command inherits the file descriptors of the call- + erwise, the invoked command inherits the file descriptors of the call- ing shell as modified by redirections. EENNVVIIRROONNMMEENNTT - When a program is invoked it is given an array of strings called the + When a program is invoked it is given an array of strings called the _e_n_v_i_r_o_n_m_e_n_t. This is a list of _n_a_m_e-_v_a_l_u_e pairs, of the form _n_a_m_e=_v_a_l_u_e. - The shell provides several ways to manipulate the environment. On in- - vocation, the shell scans its own environment and creates a parameter - for each name found, automatically marking it for _e_x_p_o_r_t to child pro- + The shell provides several ways to manipulate the environment. On in- + vocation, the shell scans its own environment and creates a parameter + for each name found, automatically marking it for _e_x_p_o_r_t to child pro- cesses. Executed commands inherit the environment. The eexxppoorrtt and ddee-- - ccllaarree --xx commands allow parameters and functions to be added to and + ccllaarree --xx commands allow parameters and functions to be added to and deleted from the environment. If the value of a parameter in the envi- ronment is modified, the new value becomes part of the environment, re- - placing the old. The environment inherited by any executed command - consists of the shell's initial environment, whose values may be modi- - fied in the shell, less any pairs removed by the uunnsseett command, plus + placing the old. The environment inherited by any executed command + consists of the shell's initial environment, whose values may be modi- + fied in the shell, less any pairs removed by the uunnsseett command, plus any additions via the eexxppoorrtt and ddeeccllaarree --xx commands. - The environment for any _s_i_m_p_l_e _c_o_m_m_a_n_d or function may be augmented - temporarily by prefixing it with parameter assignments, as described + The environment for any _s_i_m_p_l_e _c_o_m_m_a_n_d or function may be augmented + temporarily by prefixing it with parameter assignments, as described above in PPAARRAAMMEETTEERRSS. These assignment statements affect only the envi- ronment seen by that command. - If the --kk option is set (see the sseett builtin command below), then _a_l_l - parameter assignments are placed in the environment for a command, not + If the --kk option is set (see the sseett builtin command below), then _a_l_l + parameter assignments are placed in the environment for a command, not just those that precede the command name. - When bbaasshh invokes an external command, the variable __ is set to the + When bbaasshh invokes an external command, the variable __ is set to the full filename of the command and passed to that command in its environ- ment. EEXXIITT SSTTAATTUUSS - The exit status of an executed command is the value returned by the + The exit status of an executed command is the value returned by the _w_a_i_t_p_i_d system call or equivalent function. Exit statuses fall between - 0 and 255, though, as explained below, the shell may use values above + 0 and 255, though, as explained below, the shell may use values above 125 specially. Exit statuses from shell builtins and compound commands are also limited to this range. Under certain circumstances, the shell will use special values to indicate specific failure modes. For the shell's purposes, a command which exits with a zero exit status - has succeeded. An exit status of zero indicates success. A non-zero - exit status indicates failure. When a command terminates on a fatal + has succeeded. An exit status of zero indicates success. A non-zero + exit status indicates failure. When a command terminates on a fatal signal _N, bbaasshh uses the value of 128+_N as the exit status. - If a command is not found, the child process created to execute it re- - turns a status of 127. If a command is found but is not executable, + If a command is not found, the child process created to execute it re- + turns a status of 127. If a command is found but is not executable, the return status is 126. If a command fails because of an error during expansion or redirection, the exit status is greater than zero. - Shell builtin commands return a status of 0 (_t_r_u_e) if successful, and - non-zero (_f_a_l_s_e) if an error occurs while they execute. All builtins - return an exit status of 2 to indicate incorrect usage, generally in- + Shell builtin commands return a status of 0 (_t_r_u_e) if successful, and + non-zero (_f_a_l_s_e) if an error occurs while they execute. All builtins + return an exit status of 2 to indicate incorrect usage, generally in- valid options or missing arguments. The exit status of the last command is available in the special parame- ter $?. - BBaasshh itself returns the exit status of the last command executed, un- - less a syntax error occurs, in which case it exits with a non-zero + BBaasshh itself returns the exit status of the last command executed, un- + less a syntax error occurs, in which case it exits with a non-zero value. See also the eexxiitt builtin command below. SSIIGGNNAALLSS - When bbaasshh is interactive, in the absence of any traps, it ignores + When bbaasshh is interactive, in the absence of any traps, it ignores SSIIGGTTEERRMM (so that kkiillll 00 does not kill an interactive shell), and SSIIGGIINNTT - is caught and handled (so that the wwaaiitt builtin is interruptible). In + is caught and handled (so that the wwaaiitt builtin is interruptible). In all cases, bbaasshh ignores SSIIGGQQUUIITT. If job control is in effect, bbaasshh ig- nores SSIIGGTTTTIINN, SSIIGGTTTTOOUU, and SSIIGGTTSSTTPP. Non-builtin commands run by bbaasshh have signal handlers set to the values inherited by the shell from its parent. When job control is not in ef- - fect, asynchronous commands ignore SSIIGGIINNTT and SSIIGGQQUUIITT in addition to - these inherited handlers. Commands run as a result of command substi- + fect, asynchronous commands ignore SSIIGGIINNTT and SSIIGGQQUUIITT in addition to + these inherited handlers. Commands run as a result of command substi- tution ignore the keyboard-generated job control signals SSIIGGTTTTIINN, SSIIGGTT-- TTOOUU, and SSIIGGTTSSTTPP. - The shell exits by default upon receipt of a SSIIGGHHUUPP. Before exiting, - an interactive shell resends the SSIIGGHHUUPP to all jobs, running or + The shell exits by default upon receipt of a SSIIGGHHUUPP. Before exiting, + an interactive shell resends the SSIIGGHHUUPP to all jobs, running or stopped. Stopped jobs are sent SSIIGGCCOONNTT to ensure that they receive the - SSIIGGHHUUPP. To prevent the shell from sending the signal to a particular - job, it should be removed from the jobs table with the ddiissoowwnn builtin - (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below) or marked to not receive SSIIGGHHUUPP us- + SSIIGGHHUUPP. To prevent the shell from sending the signal to a particular + job, it should be removed from the jobs table with the ddiissoowwnn builtin + (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below) or marked to not receive SSIIGGHHUUPP us- ing ddiissoowwnn --hh. - If the hhuuppoonneexxiitt shell option has been set with sshhoopptt, bbaasshh sends a + If the hhuuppoonneexxiitt shell option has been set with sshhoopptt, bbaasshh sends a SSIIGGHHUUPP to all jobs when an interactive login shell exits. - If bbaasshh is waiting for a command to complete and receives a signal for + If bbaasshh is waiting for a command to complete and receives a signal for which a trap has been set, the trap will not be executed until the com- - mand completes. When bbaasshh is waiting for an asynchronous command via - the wwaaiitt builtin, the reception of a signal for which a trap has been + mand completes. When bbaasshh is waiting for an asynchronous command via + the wwaaiitt builtin, the reception of a signal for which a trap has been set will cause the wwaaiitt builtin to return immediately with an exit sta- tus greater than 128, immediately after which the trap is executed. + When job control is not enabled, and bbaasshh is waiting for a foreground + command to complete, the shell receives keyboard-generated signals such + as SSIIGGIINNTT (usually generated by ^^CC) that users commonly intend to send + to that command. This happens because the shell and the command are in + the same process group as the terminal, and ^^CC sends SSIIGGIINNTT to all pro- + cesses in that process group. + + When bbaasshh is running without job control enabled and receives SSIIGGIINNTT + while waiting for a foreground command, it waits until that foreground + command terminates and then decides what to do about the SSIIGGIINNTT: + + 1. If the command terminates due to the SSIIGGIINNTT, bbaasshh concludes that + the user meant to end the entire script, and acts on the SSIIGGIINNTT + (e.g., by running a SSIIGGIINNTT trap or exiting itself); + + 2. If the command does not terminate due to SSIIGGIINNTT, the program + handled the SSIIGGIINNTT itself and did not treat it as a fatal sig- + nal. In that case, bbaasshh does not treat SSIIGGIINNTT as a fatal sig- + nal, either, instead assuming that the SSIIGGIINNTT was used as part + of the program's normal operation (e.g., emacs uses it to abort + editing commands) or deliberately discarded. However, bbaasshh will + run any trap set on SSIIGGIINNTT, as it does with any other trapped + signal it receives while it is waiting for the foreground com- + mand to complete, for compatibility. + JJOOBB CCOONNTTRROOLL _J_o_b _c_o_n_t_r_o_l refers to the ability to selectively stop (_s_u_s_p_e_n_d) the ex- ecution of processes and continue (_r_e_s_u_m_e) their execution at a later @@ -5754,6 +5780,7 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS ccoommppaatt4422 ccoommppaatt4433 ccoommppaatt4444 + ccoommppaatt5500 These control aspects of the shell's compatibility mode (see SSHHEELLLL CCOOMMPPAATTIIBBIILLIITTYY MMOODDEE below). @@ -5969,74 +5996,80 @@ SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS PPaatthhnnaammee EExxppaannssiioonn above) to expand to a null string, rather than themselves. + ppaattssuubb__rreeppllaacceemmeenntt + If set, bbaasshh expands occurrences of && in the replacement + string of pattern substitution to the text matched by + the pattern, as described under PPaarraammeetteerr EExxppaannssiioonn + above. This option is enabled by default. + pprrooggccoommpp If set, the programmable completion facilities (see PPrroo-- ggrraammmmaabbllee CCoommpplleettiioonn above) are enabled. This option is enabled by default. pprrooggccoommpp__aalliiaass - If set, and programmable completion is enabled, bbaasshh - treats a command name that doesn't have any completions - as a possible alias and attempts alias expansion. If it - has an alias, bbaasshh attempts programmable completion us- + If set, and programmable completion is enabled, bbaasshh + treats a command name that doesn't have any completions + as a possible alias and attempts alias expansion. If it + has an alias, bbaasshh attempts programmable completion us- ing the command word resulting from the expanded alias. pprroommppttvvaarrss If set, prompt strings undergo parameter expansion, com- - mand substitution, arithmetic expansion, and quote re- - moval after being expanded as described in PPRROOMMPPTTIINNGG + mand substitution, arithmetic expansion, and quote re- + moval after being expanded as described in PPRROOMMPPTTIINNGG above. This option is enabled by default. rreessttrriicctteedd__sshheellll - The shell sets this option if it is started in re- - stricted mode (see RREESSTTRRIICCTTEEDD SSHHEELLLL below). The value - may not be changed. This is not reset when the startup - files are executed, allowing the startup files to dis- + The shell sets this option if it is started in re- + stricted mode (see RREESSTTRRIICCTTEEDD SSHHEELLLL below). The value + may not be changed. This is not reset when the startup + files are executed, allowing the startup files to dis- cover whether or not a shell is restricted. sshhiifftt__vveerrbboossee - If set, the sshhiifftt builtin prints an error message when + If set, the sshhiifftt builtin prints an error message when the shift count exceeds the number of positional parame- ters. ssoouurrcceeppaatthh If set, the .. (ssoouurrccee) builtin uses the value of PPAATTHH to - find the directory containing the file supplied as an + find the directory containing the file supplied as an argument. This option is enabled by default. vvaarrrreeddiirr__cclloossee - If set, the shell automatically closes file descriptors + If set, the shell automatically closes file descriptors assigned using the _{_v_a_r_n_a_m_e_} redirection syntax (see RREE-- - DDIIRREECCTTIIOONN above) instead of leaving them open when the + DDIIRREECCTTIIOONN above) instead of leaving them open when the command completes. xxppgg__eecchhoo - If set, the eecchhoo builtin expands backslash-escape se- + If set, the eecchhoo builtin expands backslash-escape se- quences by default. ssuussppeenndd [--ff] - Suspend the execution of this shell until it receives a SSIIGGCCOONNTT + Suspend the execution of this shell until it receives a SSIIGGCCOONNTT signal. A login shell cannot be suspended; the --ff option can be used to override this and force the suspension. The return sta- - tus is 0 unless the shell is a login shell and --ff is not sup- + tus is 0 unless the shell is a login shell and --ff is not sup- plied, or if job control is not enabled. 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. @@ -6053,139 +6086,139 @@ 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. - When used with tteesstt or [[, the << and >> operators sort lexico- + When used with tteesstt or [[, the << and >> operators sort lexico- graphically using ASCII ordering. - 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_r_g] _s_i_g_s_p_e_c ...] - The command _a_r_g is to be read and executed when the shell re- + The command _a_r_g is to be read and executed when the shell re- ceives signal(s) _s_i_g_s_p_e_c. If _a_r_g is absent (and there is a sin- - gle _s_i_g_s_p_e_c) or --, each specified signal is reset to its origi- - nal disposition (the value it had upon entrance to the shell). - If _a_r_g 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 invokes. If _a_r_g - is not present and --pp has been supplied, then the trap commands + gle _s_i_g_s_p_e_c) or --, each specified signal is reset to its origi- + nal disposition (the value it had upon entrance to the shell). + If _a_r_g 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 invokes. If _a_r_g + is not present and --pp has been supplied, then the trap commands associated with each _s_i_g_s_p_e_c are displayed. If no arguments are - supplied or if only --pp is given, ttrraapp prints the list of com- - mands associated with each signal. The --ll option causes the - shell 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 + supplied or if only --pp is given, ttrraapp prints the list of com- + mands associated with each signal. The --ll option causes the + shell 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_r_g is executed on exit - from the shell. If a _s_i_g_s_p_e_c is DDEEBBUUGG, the command _a_r_g is exe- - cuted 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, every arithmetic _f_o_r command, and before the - first command executes in a shell function (see SSHHEELLLL GGRRAAMMMMAARR - above). Refer to the description of the eexxttddeebbuugg option to the + If a _s_i_g_s_p_e_c is EEXXIITT (0) the command _a_r_g is executed on exit + from the shell. If a _s_i_g_s_p_e_c is DDEEBBUUGG, the command _a_r_g is exe- + cuted 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, every arithmetic _f_o_r command, and before the + first command executes in a shell function (see SSHHEELLLL GGRRAAMMMMAARR + above). Refer to the description of the eexxttddeebbuugg option to the sshhoopptt builtin for details of its effect on the DDEEBBUUGG trap. If a _s_i_g_s_p_e_c is RREETTUURRNN, the command _a_r_g is executed each time a shell function or a script executed with the .. or ssoouurrccee builtins fin- ishes executing. - If a _s_i_g_s_p_e_c is EERRRR, the command _a_r_g is executed whenever a + If a _s_i_g_s_p_e_c is EERRRR, the command _a_r_g 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. Signals ignored upon entry to the shell cannot be trapped or re- - set. Trapped signals that are not being ignored are reset to + set. 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 is false if any _s_i_g_s_p_e_c is + one is created. The return status is false if any _s_i_g_s_p_e_c is invalid; otherwise ttrraapp returns true. 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 disk file, respectively. If the _n_a_m_e is not found, - then nothing is printed, and an exit status of false is re- - turned. If the --pp option is used, ttyyppee either returns the name - of the disk file that would be executed if _n_a_m_e were specified - as a command name, or nothing if ``type -t name'' would not re- - turn _f_i_l_e. The --PP option forces a PPAATTHH search for each _n_a_m_e, + 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 disk file, respectively. If the _n_a_m_e is not found, + then nothing is printed, and an exit status of false is re- + turned. If the --pp option is used, ttyyppee either returns the name + of the disk file that would be executed if _n_a_m_e were specified + as a command name, or nothing if ``type -t name'' would not re- + turn _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 necessar- - ily the file that appears first in PPAATTHH. If the --aa option is - used, ttyyppee prints all of the places that contain an executable + ily the file that appears first in PPAATTHH. If the --aa option is + used, ttyyppee prints all of the places that contain an executable named _n_a_m_e. This includes aliases and functions, if and only if the --pp option is not also used. The table of hashed commands is - not consulted when using --aa. The --ff option suppresses shell + not consulted when using --aa. 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) @@ -6194,132 +6227,132 @@ 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. Otherwise, the return status is the + changes status. If _i_d specifies a non-existent process or job, + the return status is 127. 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 `shell compatibility level', spec- ified as a set of options to the shopt builtin ccoommppaatt3311, ccoommppaatt3322, ccoomm-- - ppaatt4400, ccoommppaatt4411, and so on). There is only one current compatibility + ppaatt4400, ccoommppaatt4411, and so on). There is only one current compatibility level -- each option is mutually exclusive. The compatibility level is - intended to allow users to select behavior from previous versions that - is incompatible with newer versions while they migrate scripts to use - current features and behavior. It's intended to be a temporary solu- + intended to allow users to select behavior from previous versions that + is incompatible with newer versions while they migrate scripts to use + current features and behavior. It's intended to be a temporary solu- tion. - 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 above). - 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 @@ -6327,108 +6360,108 @@ 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 (declare -a foo='(1 2)'). Later versions + +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 (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. 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- @@ -6437,10 +6470,10 @@ 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 @@ -6450,14 +6483,14 @@ RREESSTTRRIICCTTEEDD 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 @@ -6475,10 +6508,10 @@ 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 @@ -6492,15 +6525,15 @@ 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: @@ -6511,7 +6544,7 @@ 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 @@ -6528,10 +6561,10 @@ 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. @@ -6540,4 +6573,4 @@ BBUUGGSS -GNU Bash 5.1 2021 October 8 BASH(1) +GNU Bash 5.1 2021 October 25 BASH(1) diff --git a/doc/bash.1 b/doc/bash.1 index 537337d2..d9dfb9e4 100644 --- a/doc/bash.1 +++ b/doc/bash.1 @@ -5,12 +5,12 @@ .\" Case Western Reserve University .\" chet.ramey@case.edu .\" -.\" Last Change: Tue Oct 19 11:34:57 EDT 2021 +.\" Last Change: Mon Oct 25 11:23:10 EDT 2021 .\" .\" bash_builtins, strip all but Built-Ins section .if \n(zZ=1 .ig zZ .if \n(zY=1 .ig zY -.TH BASH 1 "2021 October 19" "GNU Bash 5.1" +.TH BASH 1 "2021 October 25" "GNU Bash 5.1" .\" .\" There's some problem with having a `@' .\" in a tagged paragraph with the BSD man macros. @@ -3367,7 +3367,8 @@ matches of \fIpattern\fP are deleted. If \fIstring\fP is null, matches of \fIpattern\fP are deleted and the \fB/\fP following \fIpattern\fP may be omitted. -Any unquoted instances of \fB&\fP in \fIstring\fP are replaced with the +If the \fBpatsub_replacement\fP shell option is enabled using \fBshopt\fP, +any unquoted instances of \fB&\fP in \fIstring\fP are replaced with the matching portion of \fIpattern\fP. Backslash is used to quote \fB&\fP in \fIstring\fP; the backslash is removed in order to permit a literal \fB&\fP in the replacement string. @@ -10481,6 +10482,13 @@ files (see above) to expand to a null string, rather than themselves. .TP 8 +.B patsub_replacement +If set, \fBbash\fP +expands occurrences of \fB&\fP in the replacement string of pattern +substitution to the text matched by the pattern, as described +under \fBParameter Expansion\fP above. +This option is enabled by default. +.TP 8 .B progcomp If set, the programmable completion facilities (see \fBProgrammable Completion\fP above) are enabled. diff --git a/doc/bashref.info b/doc/bashref.info index 9595aa9f..d6646c54 100644 --- a/doc/bashref.info +++ b/doc/bashref.info @@ -2,9 +2,9 @@ This is bashref.info, produced by makeinfo version 6.8 from bashref.texi. This text is a brief description of the features that are present in the -Bash shell (version 5.1, 15 October 2021). +Bash shell (version 5.1, 25 October 2021). - This is Edition 5.1, last updated 15 October 2021, of 'The GNU Bash + This is Edition 5.1, last updated 25 October 2021, of 'The GNU Bash Reference Manual', for 'Bash', Version 5.1. Copyright (C) 1988-2021 Free Software Foundation, Inc. @@ -27,10 +27,10 @@ Bash Features ************* This text is a brief description of the features that are present in the -Bash shell (version 5.1, 15 October 2021). The Bash home page is +Bash shell (version 5.1, 25 October 2021). The Bash home page is . - This is Edition 5.1, last updated 15 October 2021, of 'The GNU Bash + This is Edition 5.1, last updated 25 October 2021, of 'The GNU Bash Reference Manual', for 'Bash', Version 5.1. Bash contains features that appear in other popular shells, and some @@ -2076,7 +2076,8 @@ omitted, the operator tests only for existence. of PATTERN are deleted and the '/' following PATTERN may be omitted. - Any unquoted instances of '&' in STRING are replaced with the + If the 'patsub_replacement' shell option is enabled using 'shopt', + any unquoted instances of '&' in STRING are replaced with the matching portion of PATTERN. This is intended to duplicate a common 'sed' idiom. Backslash is used to quote '&' in STRING; the backslash is removed in order to permit a literal '&' in the @@ -3022,6 +3023,33 @@ the 'wait' builtin, the reception of a signal for which a trap has been set will cause the 'wait' builtin to return immediately with an exit status greater than 128, immediately after which the trap is executed. + When job control is not enabled, and Bash is waiting for a foreground +command to complete, the shell receives keyboard-generated signals such +as 'SIGINT' (usually generated by '^C') that users commonly intend to +send to that command. This happens because the shell and the command +are in the same process group as the terminal, and '^C' sends 'SIGINT' +to all processes in that process group. See *note Job Control::, for a +more in-depth discussion of process groups. + + When Bash is running without job control enabled and receives +'SIGINT' while waiting for a foreground command, it waits until that +foreground command terminates and then decides what to do about the +'SIGINT': + + 1. If the command terminates due to the 'SIGINT', Bash concludes that + the user meant to end the entire script, and acts on the 'SIGINT' + (e.g., by running a 'SIGINT' trap or exiting itself); + + 2. If the pipeline does not terminate due to 'SIGINT', the program + handled the 'SIGINT' itself and did not treat it as a fatal signal. + In that case, Bash does not treat 'SIGINT' as a fatal signal, + either, instead assuming that the 'SIGINT' was used as part of the + program's normal operation (e.g., 'emacs' uses it to abort editing + commands) or deliberately discarded. However, Bash will run any + trap set on 'SIGINT', as it does with any other trapped signal it + receives while it is waiting for the foreground command to + complete, for compatibility. +  File: bashref.info, Node: Shell Scripts, Prev: Executing Commands, Up: Basic Shell Features @@ -4932,6 +4960,12 @@ This builtin allows you to change additional shell optional behavior. If set, Bash allows filename patterns which match no files to expand to a null string, rather than themselves. + 'patsub_replacement' + If set, Bash expands occurrences of '&' in the replacement + string of pattern substitution to the text matched by the + pattern, as described above (*note Shell Parameter + Expansion::). This option is enabled by default. + 'progcomp' If set, the programmable completion facilities (*note Programmable Completion::) are enabled. This option is @@ -12373,103 +12407,103 @@ Node: Shell Expansions69747 Node: Brace Expansion71874 Node: Tilde Expansion74608 Node: Shell Parameter Expansion77229 -Node: Command Substitution95023 -Node: Arithmetic Expansion96378 -Node: Process Substitution97346 -Node: Word Splitting98466 -Node: Filename Expansion100410 -Node: Pattern Matching103010 -Node: Quote Removal107618 -Node: Redirections107913 -Node: Executing Commands117573 -Node: Simple Command Expansion118243 -Node: Command Search and Execution120353 -Node: Command Execution Environment122731 -Node: Environment125766 -Node: Exit Status127429 -Node: Signals129213 -Node: Shell Scripts131180 -Node: Shell Builtin Commands134207 -Node: Bourne Shell Builtins136245 -Node: Bash Builtins157706 -Node: Modifying Shell Behavior188523 -Node: The Set Builtin188868 -Node: The Shopt Builtin199281 -Node: Special Builtins214710 -Node: Shell Variables215689 -Node: Bourne Shell Variables216126 -Node: Bash Variables218230 -Node: Bash Features251045 -Node: Invoking Bash252058 -Node: Bash Startup Files258071 -Node: Interactive Shells263174 -Node: What is an Interactive Shell?263584 -Node: Is this Shell Interactive?264233 -Node: Interactive Shell Behavior265048 -Node: Bash Conditional Expressions268561 -Node: Shell Arithmetic273203 -Node: Aliases276147 -Node: Arrays278760 -Node: The Directory Stack284769 -Node: Directory Stack Builtins285553 -Node: Controlling the Prompt289813 -Node: The Restricted Shell292778 -Node: Bash POSIX Mode295375 -Node: Shell Compatibility Mode306648 -Node: Job Control313304 -Node: Job Control Basics313764 -Node: Job Control Builtins318766 -Node: Job Control Variables324166 -Node: Command Line Editing325322 -Node: Introduction and Notation326993 -Node: Readline Interaction328616 -Node: Readline Bare Essentials329807 -Node: Readline Movement Commands331590 -Node: Readline Killing Commands332550 -Node: Readline Arguments334468 -Node: Searching335512 -Node: Readline Init File337698 -Node: Readline Init File Syntax338959 -Node: Conditional Init Constructs360239 -Node: Sample Init File364435 -Node: Bindable Readline Commands367559 -Node: Commands For Moving368763 -Node: Commands For History370814 -Node: Commands For Text375808 -Node: Commands For Killing379457 -Node: Numeric Arguments382490 -Node: Commands For Completion383629 -Node: Keyboard Macros387820 -Node: Miscellaneous Commands388507 -Node: Readline vi Mode394446 -Node: Programmable Completion395353 -Node: Programmable Completion Builtins403133 -Node: A Programmable Completion Example413828 -Node: Using History Interactively419075 -Node: Bash History Facilities419759 -Node: Bash History Builtins422764 -Node: History Interaction427772 -Node: Event Designators431392 -Node: Word Designators432746 -Node: Modifiers434506 -Node: Installing Bash436317 -Node: Basic Installation437454 -Node: Compilers and Options441176 -Node: Compiling For Multiple Architectures441917 -Node: Installation Names443610 -Node: Specifying the System Type445719 -Node: Sharing Defaults446435 -Node: Operation Controls447108 -Node: Optional Features448066 -Node: Reporting Bugs459159 -Node: Major Differences From The Bourne Shell460434 -Node: GNU Free Documentation License477284 -Node: Indexes502461 -Node: Builtin Index502915 -Node: Reserved Word Index509742 -Node: Variable Index512190 -Node: Function Index528682 -Node: Concept Index542466 +Node: Command Substitution95095 +Node: Arithmetic Expansion96450 +Node: Process Substitution97418 +Node: Word Splitting98538 +Node: Filename Expansion100482 +Node: Pattern Matching103082 +Node: Quote Removal107690 +Node: Redirections107985 +Node: Executing Commands117645 +Node: Simple Command Expansion118315 +Node: Command Search and Execution120425 +Node: Command Execution Environment122803 +Node: Environment125838 +Node: Exit Status127501 +Node: Signals129285 +Node: Shell Scripts132734 +Node: Shell Builtin Commands135761 +Node: Bourne Shell Builtins137799 +Node: Bash Builtins159260 +Node: Modifying Shell Behavior190077 +Node: The Set Builtin190422 +Node: The Shopt Builtin200835 +Node: Special Builtins216549 +Node: Shell Variables217528 +Node: Bourne Shell Variables217965 +Node: Bash Variables220069 +Node: Bash Features252884 +Node: Invoking Bash253897 +Node: Bash Startup Files259910 +Node: Interactive Shells265013 +Node: What is an Interactive Shell?265423 +Node: Is this Shell Interactive?266072 +Node: Interactive Shell Behavior266887 +Node: Bash Conditional Expressions270400 +Node: Shell Arithmetic275042 +Node: Aliases277986 +Node: Arrays280599 +Node: The Directory Stack286608 +Node: Directory Stack Builtins287392 +Node: Controlling the Prompt291652 +Node: The Restricted Shell294617 +Node: Bash POSIX Mode297214 +Node: Shell Compatibility Mode308487 +Node: Job Control315143 +Node: Job Control Basics315603 +Node: Job Control Builtins320605 +Node: Job Control Variables326005 +Node: Command Line Editing327161 +Node: Introduction and Notation328832 +Node: Readline Interaction330455 +Node: Readline Bare Essentials331646 +Node: Readline Movement Commands333429 +Node: Readline Killing Commands334389 +Node: Readline Arguments336307 +Node: Searching337351 +Node: Readline Init File339537 +Node: Readline Init File Syntax340798 +Node: Conditional Init Constructs362078 +Node: Sample Init File366274 +Node: Bindable Readline Commands369398 +Node: Commands For Moving370602 +Node: Commands For History372653 +Node: Commands For Text377647 +Node: Commands For Killing381296 +Node: Numeric Arguments384329 +Node: Commands For Completion385468 +Node: Keyboard Macros389659 +Node: Miscellaneous Commands390346 +Node: Readline vi Mode396285 +Node: Programmable Completion397192 +Node: Programmable Completion Builtins404972 +Node: A Programmable Completion Example415667 +Node: Using History Interactively420914 +Node: Bash History Facilities421598 +Node: Bash History Builtins424603 +Node: History Interaction429611 +Node: Event Designators433231 +Node: Word Designators434585 +Node: Modifiers436345 +Node: Installing Bash438156 +Node: Basic Installation439293 +Node: Compilers and Options443015 +Node: Compiling For Multiple Architectures443756 +Node: Installation Names445449 +Node: Specifying the System Type447558 +Node: Sharing Defaults448274 +Node: Operation Controls448947 +Node: Optional Features449905 +Node: Reporting Bugs460998 +Node: Major Differences From The Bourne Shell462273 +Node: GNU Free Documentation License479123 +Node: Indexes504300 +Node: Builtin Index504754 +Node: Reserved Word Index511581 +Node: Variable Index514029 +Node: Function Index530521 +Node: Concept Index544305  End Tag Table diff --git a/doc/bashref.texi b/doc/bashref.texi index eff82cee..cfa1e57a 100644 --- a/doc/bashref.texi +++ b/doc/bashref.texi @@ -2440,7 +2440,8 @@ If @var{string} is null, matches of @var{pattern} are deleted and the @samp{/} following @var{pattern} may be omitted. -Any unquoted instances of @samp{&} in @var{string} are replaced with the +If the @code{patsub_replacement} shell option is enabled using @code{shopt}, +any unquoted instances of @samp{&} in @var{string} are replaced with the matching portion of @var{pattern}. This is intended to duplicate a common @code{sed} idiom. Backslash is used to quote @samp{&} in @var{string}; the backslash is removed @@ -5786,6 +5787,13 @@ If the string is not translated, this has no effect. If set, Bash allows filename patterns which match no files to expand to a null string, rather than themselves. +@item patsub_replacement +If set, Bash +expands occurrences of @samp{&} in the replacement string of pattern +substitution to the text matched by the pattern, as described +above (@pxref{Shell Parameter Expansion}). +This option is enabled by default. + @item progcomp If set, the programmable completion facilities (@pxref{Programmable Completion}) are enabled. diff --git a/doc/version.texi b/doc/version.texi index c65f9885..10d21ea3 100644 --- a/doc/version.texi +++ b/doc/version.texi @@ -2,10 +2,10 @@ Copyright (C) 1988-2021 Free Software Foundation, Inc. @end ignore -@set LASTCHANGE Tue Oct 19 11:34:34 EDT 2021 +@set LASTCHANGE Mon Oct 25 11:21:24 EDT 2021 @set EDITION 5.1 @set VERSION 5.1 -@set UPDATED 19 October 2021 +@set UPDATED 25 October 2021 @set UPDATED-MONTH October 2021 diff --git a/tests/RUN-ONE-TEST b/tests/RUN-ONE-TEST index 0b063810..c8bef8dd 100755 --- a/tests/RUN-ONE-TEST +++ b/tests/RUN-ONE-TEST @@ -1,4 +1,4 @@ -BUILD_DIR=/usr/local/build/chet/bash/bash-current +BUILD_DIR=/usr/local/build/bash/bash-current THIS_SH=$BUILD_DIR/bash PATH=$PATH:$BUILD_DIR diff --git a/tests/shopt.right b/tests/shopt.right index b659c8b2..177ea2f0 100644 --- a/tests/shopt.right +++ b/tests/shopt.right @@ -48,6 +48,7 @@ shopt -u nocaseglob shopt -u nocasematch shopt -u noexpand_translation shopt -u nullglob +shopt -s patsub_replacement shopt -s progcomp shopt -u progcomp_alias shopt -s promptvars @@ -70,6 +71,7 @@ shopt -s force_fignore shopt -s globasciiranges shopt -s hostcomplete shopt -s interactive_comments +shopt -s patsub_replacement shopt -s progcomp shopt -s promptvars shopt -s sourcepath