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diff --git a/doc/builtins.0 b/doc/builtins.0 new file mode 100644 index 0000000..a721e38 --- /dev/null +++ b/doc/builtins.0 @@ -0,0 +1,1579 @@ +BASH_BUILTINS(1) BASH_BUILTINS(1) + + + +NNAAMMEE + bash, :, ., [, alias, bg, bind, break, builtin, caller, cd, command, + compgen, complete, compopt, continue, declare, dirs, disown, echo, + enable, eval, exec, exit, export, false, fc, fg, getopts, hash, help, + history, jobs, kill, let, local, logout, mapfile, popd, printf, pushd, + pwd, read, readonly, return, set, shift, shopt, source, suspend, test, + times, trap, true, type, typeset, ulimit, umask, unalias, unset, wait - + bash built-in commands, see bbaasshh(1) + +BBAASSHH BBUUIILLTTIINN CCOOMMMMAANNDDSS + Unless otherwise noted, each builtin command documented in this section + as accepting options preceded by -- accepts ---- to signify the end of the + options. The ::, ttrruuee, ffaallssee, and tteesstt builtins do not accept options + and do not treat ---- specially. The eexxiitt, llooggoouutt, bbrreeaakk, ccoonnttiinnuuee, lleett, + and sshhiifftt builtins accept and process arguments beginning with -- with- + out requiring ----. Other builtins that accept arguments but are not + specified as accepting options interpret arguments beginning with -- as + invalid options and require ---- to prevent this interpretation. + :: [_a_r_g_u_m_e_n_t_s] + No effect; the command does nothing beyond expanding _a_r_g_u_m_e_n_t_s + and performing any specified redirections. A zero exit code is + returned. + + .. _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s] + ssoouurrccee _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s] + Read and execute commands from _f_i_l_e_n_a_m_e in the current shell + environment and return the exit status of the last command exe- + cuted from _f_i_l_e_n_a_m_e. If _f_i_l_e_n_a_m_e does not contain a slash, file + names in PPAATTHH are used to find the directory containing _f_i_l_e_- + _n_a_m_e. The file searched for in PPAATTHH need not be executable. + When bbaasshh is not in _p_o_s_i_x _m_o_d_e, the current directory is + searched if no file is found in PPAATTHH. If the ssoouurrcceeppaatthh option + to the sshhoopptt builtin command is turned off, the PPAATTHH is not + searched. If any _a_r_g_u_m_e_n_t_s are supplied, they become the posi- + tional parameters when _f_i_l_e_n_a_m_e is executed. Otherwise the + positional parameters are unchanged. The return status is the + status of the last command exited within the script (0 if no + commands are executed), and false if _f_i_l_e_n_a_m_e is not found or + cannot be read. + + aalliiaass [--pp] [_n_a_m_e[=_v_a_l_u_e] ...] + AAlliiaass with no arguments or with the --pp option prints the list of + aliases in the form aalliiaass _n_a_m_e=_v_a_l_u_e on standard output. When + arguments are supplied, an alias is defined for each _n_a_m_e whose + _v_a_l_u_e is given. A trailing space in _v_a_l_u_e causes the next word + to be checked for alias substitution when the alias is expanded. + For each _n_a_m_e in the argument list for which no _v_a_l_u_e is sup- + plied, the name and value of the alias is printed. AAlliiaass + returns true unless a _n_a_m_e is given for which no alias has been + defined. + + bbgg [_j_o_b_s_p_e_c ...] + Resume each suspended job _j_o_b_s_p_e_c in the background, as if it + had been started with &&. If _j_o_b_s_p_e_c is not present, the shell's + notion of the _c_u_r_r_e_n_t _j_o_b is used. bbgg _j_o_b_s_p_e_c returns 0 unless + run when job control is disabled or, when run with job control + enabled, any specified _j_o_b_s_p_e_c was not found or was started + without job control. + + bbiinndd [--mm _k_e_y_m_a_p] [--llppssvvPPSSVV] + bbiinndd [--mm _k_e_y_m_a_p] [--qq _f_u_n_c_t_i_o_n] [--uu _f_u_n_c_t_i_o_n] [--rr _k_e_y_s_e_q] + bbiinndd [--mm _k_e_y_m_a_p] --ff _f_i_l_e_n_a_m_e + bbiinndd [--mm _k_e_y_m_a_p] --xx _k_e_y_s_e_q:_s_h_e_l_l_-_c_o_m_m_a_n_d + bbiinndd [--mm _k_e_y_m_a_p] _k_e_y_s_e_q:_f_u_n_c_t_i_o_n_-_n_a_m_e + bbiinndd _r_e_a_d_l_i_n_e_-_c_o_m_m_a_n_d + Display current rreeaaddlliinnee key and function bindings, bind a key + sequence to a rreeaaddlliinnee function or macro, or set a rreeaaddlliinnee + variable. Each non-option argument is a command as it would + appear in _._i_n_p_u_t_r_c, but each binding or command must be passed + as a separate argument; e.g., '"\C-x\C-r": re-read-init-file'. + Options, if supplied, have the following meanings: + --mm _k_e_y_m_a_p + Use _k_e_y_m_a_p as the keymap to be affected by the subsequent + bindings. Acceptable _k_e_y_m_a_p names are _e_m_a_c_s_, _e_m_a_c_s_-_s_t_a_n_- + _d_a_r_d_, _e_m_a_c_s_-_m_e_t_a_, _e_m_a_c_s_-_c_t_l_x_, _v_i_, _v_i_-_m_o_v_e_, _v_i_-_c_o_m_m_a_n_d, + and _v_i_-_i_n_s_e_r_t. _v_i is equivalent to _v_i_-_c_o_m_m_a_n_d; _e_m_a_c_s is + equivalent to _e_m_a_c_s_-_s_t_a_n_d_a_r_d. + --ll List the names of all rreeaaddlliinnee functions. + --pp Display rreeaaddlliinnee function names and bindings in such a + way that they can be re-read. + --PP List current rreeaaddlliinnee function names and bindings. + --ss Display rreeaaddlliinnee key sequences bound to macros and the + strings they output in such a way that they can be re- + read. + --SS Display rreeaaddlliinnee key sequences bound to macros and the + strings they output. + --vv Display rreeaaddlliinnee variable names and values in such a way + that they can be re-read. + --VV List current rreeaaddlliinnee variable names and values. + --ff _f_i_l_e_n_a_m_e + Read key bindings from _f_i_l_e_n_a_m_e. + --qq _f_u_n_c_t_i_o_n + Query about which keys invoke the named _f_u_n_c_t_i_o_n. + --uu _f_u_n_c_t_i_o_n + Unbind all keys bound to the named _f_u_n_c_t_i_o_n. + --rr _k_e_y_s_e_q + Remove any current binding for _k_e_y_s_e_q. + --xx _k_e_y_s_e_q::_s_h_e_l_l_-_c_o_m_m_a_n_d + Cause _s_h_e_l_l_-_c_o_m_m_a_n_d to be executed whenever _k_e_y_s_e_q is + entered. When _s_h_e_l_l_-_c_o_m_m_a_n_d is executed, the shell sets + the RREEAADDLLIINNEE__LLIINNEE variable to the contents of the rreeaadd-- + lliinnee line buffer and the RREEAADDLLIINNEE__PPOOIINNTT variable to the + current location of the insertion point. If the executed + command changes the value of RREEAADDLLIINNEE__LLIINNEE or RREEAADD-- + LLIINNEE__PPOOIINNTT, those new values will be reflected in the + editing state. + + The return value is 0 unless an unrecognized option is given or + an error occurred. + + bbrreeaakk [_n] + Exit from within a ffoorr, wwhhiillee, uunnttiill, or sseelleecctt loop. If _n is + specified, break _n levels. _n must be >= 1. If _n is greater + than the number of enclosing loops, all enclosing loops are + exited. The return value is 0 unless _n is not greater than or + equal to 1. + + bbuuiillttiinn _s_h_e_l_l_-_b_u_i_l_t_i_n [_a_r_g_u_m_e_n_t_s] + Execute the specified shell builtin, passing it _a_r_g_u_m_e_n_t_s, and + return its exit status. This is useful when defining a function + whose name is the same as a shell builtin, retaining the func- + tionality of the builtin within the function. The ccdd builtin is + commonly redefined this way. The return status is false if + _s_h_e_l_l_-_b_u_i_l_t_i_n is not a shell builtin command. + + ccaalllleerr [_e_x_p_r] + Returns the context of any active subroutine call (a shell func- + tion or a script executed with the .. or ssoouurrccee builtins. With- + out _e_x_p_r, ccaalllleerr displays the line number and source filename of + the current subroutine call. If a non-negative integer is sup- + plied as _e_x_p_r, ccaalllleerr displays the line number, subroutine name, + and source file corresponding to that position in the current + execution call stack. This extra information may be used, for + example, to print a stack trace. The current frame is frame 0. + The return value is 0 unless the shell is not executing a sub- + routine call or _e_x_p_r does not correspond to a valid position in + the call stack. + + ccdd [--LL||--PP] [_d_i_r] + Change the current directory to _d_i_r. The variable HHOOMMEE is the + default _d_i_r. The variable CCDDPPAATTHH defines the search path for + the directory containing _d_i_r. Alternative directory names in + CCDDPPAATTHH are separated by a colon (:). A null directory name in + CCDDPPAATTHH is the same as the current directory, i.e., ``..''. If + _d_i_r begins with a slash (/), then CCDDPPAATTHH is not used. The --PP + option says to use the physical directory structure instead of + following symbolic links (see also the --PP option to the sseett + builtin command); the --LL option forces symbolic links to be fol- + lowed. An argument of -- is equivalent to $$OOLLDDPPWWDD. If a non- + empty directory name from CCDDPPAATTHH is used, or if -- is the first + argument, and the directory change is successful, the absolute + pathname of the new working directory is written to the standard + output. The return value is true if the directory was success- + fully changed; false otherwise. + + ccoommmmaanndd [--ppVVvv] _c_o_m_m_a_n_d [_a_r_g ...] + Run _c_o_m_m_a_n_d with _a_r_g_s suppressing the normal shell function + lookup. Only builtin commands or commands found in the PPAATTHH are + executed. If the --pp option is given, the search for _c_o_m_m_a_n_d is + performed using a default value for PPAATTHH that is guaranteed to + find all of the standard utilities. If either the --VV or --vv + option is supplied, a description of _c_o_m_m_a_n_d is printed. The --vv + option causes a single word indicating the command or file name + used to invoke _c_o_m_m_a_n_d to be displayed; the --VV option produces a + more verbose description. If the --VV or --vv option is supplied, + the exit status is 0 if _c_o_m_m_a_n_d was found, and 1 if not. If + neither option is supplied and an error occurred or _c_o_m_m_a_n_d can- + not be found, the exit status is 127. Otherwise, the exit sta- + tus of the ccoommmmaanndd builtin is the exit status of _c_o_m_m_a_n_d. + + ccoommppggeenn [_o_p_t_i_o_n] [_w_o_r_d] + Generate possible completion matches for _w_o_r_d according to the + _o_p_t_i_o_ns, which may be any option accepted by the ccoommpplleettee + builtin with the exception of --pp and --rr, and write the matches + to the standard output. When using the --FF or --CC options, the + various shell variables set by the programmable completion + facilities, while available, will not have useful values. + + The matches will be generated in the same way as if the pro- + grammable completion code had generated them directly from a + completion specification with the same flags. If _w_o_r_d is speci- + fied, only those completions matching _w_o_r_d will be displayed. + + The return value is true unless an invalid option is supplied, + or no matches were generated. + + ccoommpplleettee [--aabbccddeeffggjjkkssuuvv] [--oo _c_o_m_p_-_o_p_t_i_o_n] [--DDEE] [--AA _a_c_t_i_o_n] [--GG _g_l_o_b_- + _p_a_t] [--WW _w_o_r_d_l_i_s_t] [--FF _f_u_n_c_t_i_o_n] [--CC _c_o_m_m_a_n_d] + [--XX _f_i_l_t_e_r_p_a_t] [--PP _p_r_e_f_i_x] [--SS _s_u_f_f_i_x] _n_a_m_e [_n_a_m_e _._._.] + ccoommpplleettee --pprr [--DDEE] [_n_a_m_e ...] + Specify how arguments to each _n_a_m_e should be completed. If the + --pp option is supplied, or if no options are supplied, existing + completion specifications are printed in a way that allows them + to be reused as input. The --rr option removes a completion spec- + ification for each _n_a_m_e, or, if no _n_a_m_es are supplied, all com- + pletion specifications. The --DD option indicates that the + remaining options and actions should apply to the ``default'' + command completion; that is, completion attempted on a command + for which no completion has previously been defined. The --EE + option indicates that the remaining options and actions should + apply to ``empty'' command completion; that is, completion + attempted on a blank line. + + The process of applying these completion specifications when + word completion is attempted is described above under PPrroo-- + ggrraammmmaabbllee CCoommpplleettiioonn. + + Other options, if specified, have the following meanings. The + arguments to the --GG, --WW, and --XX options (and, if necessary, the + --PP and --SS options) should be quoted to protect them from expan- + sion before the ccoommpplleettee builtin is invoked. + --oo _c_o_m_p_-_o_p_t_i_o_n + The _c_o_m_p_-_o_p_t_i_o_n controls several aspects of the comp- + spec's behavior beyond the simple generation of comple- + tions. _c_o_m_p_-_o_p_t_i_o_n may be one of: + bbaasshhddeeffaauulltt + Perform the rest of the default bbaasshh completions + if the compspec generates no matches. + ddeeffaauulltt Use readline's default filename completion if + the compspec generates no matches. + ddiirrnnaammeess + Perform directory name completion if the comp- + spec generates no matches. + ffiilleennaammeess + Tell readline that the compspec generates file- + names, so it can perform any filename-specific + processing (like adding a slash to directory + names, quoting special characters, or suppress- + ing trailing spaces). Intended to be used with + shell functions. + nnoossppaaccee Tell readline not to append a space (the + default) to words completed at the end of the + line. + pplluussddiirrss + After any matches defined by the compspec are + generated, directory name completion is + attempted and any matches are added to the + results of the other actions. + --AA _a_c_t_i_o_n + The _a_c_t_i_o_n may be one of the following to generate a + list of possible completions: + aalliiaass Alias names. May also be specified as --aa. + aarrrraayyvvaarr + Array variable names. + bbiinnddiinngg RReeaaddlliinnee key binding names. + bbuuiillttiinn Names of shell builtin commands. May also be + specified as --bb. + ccoommmmaanndd Command names. May also be specified as --cc. + ddiirreeccttoorryy + Directory names. May also be specified as --dd. + ddiissaabblleedd + Names of disabled shell builtins. + eennaabblleedd Names of enabled shell builtins. + eexxppoorrtt Names of exported shell variables. May also be + specified as --ee. + ffiillee File names. May also be specified as --ff. + ffuunnccttiioonn + Names of shell functions. + ggrroouupp Group names. May also be specified as --gg. + hheellppttooppiicc + Help topics as accepted by the hheellpp builtin. + hhoossttnnaammee + Hostnames, as taken from the file specified by + the HHOOSSTTFFIILLEE shell variable. + jjoobb Job names, if job control is active. May also + be specified as --jj. + kkeeyywwoorrdd Shell reserved words. May also be specified as + --kk. + rruunnnniinngg Names of running jobs, if job control is active. + sseerrvviiccee Service names. May also be specified as --ss. + sseettoopptt Valid arguments for the --oo option to the sseett + builtin. + sshhoopptt Shell option names as accepted by the sshhoopptt + builtin. + ssiiggnnaall Signal names. + ssttooppppeedd Names of stopped jobs, if job control is active. + uusseerr User names. May also be specified as --uu. + vvaarriiaabbllee + Names of all shell variables. May also be spec- + ified as --vv. + --GG _g_l_o_b_p_a_t + The pathname expansion pattern _g_l_o_b_p_a_t is expanded to + generate the possible completions. + --WW _w_o_r_d_l_i_s_t + The _w_o_r_d_l_i_s_t is split using the characters in the IIFFSS + special variable as delimiters, and each resultant word + is expanded. The possible completions are the members + of the resultant list which match the word being com- + pleted. + --CC _c_o_m_m_a_n_d + _c_o_m_m_a_n_d is executed in a subshell environment, and its + output is used as the possible completions. + --FF _f_u_n_c_t_i_o_n + The shell function _f_u_n_c_t_i_o_n is executed in the current + shell environment. When it finishes, the possible com- + pletions are retrieved from the value of the CCOOMMPPRREEPPLLYY + array variable. + --XX _f_i_l_t_e_r_p_a_t + _f_i_l_t_e_r_p_a_t is a pattern as used for pathname expansion. + It is applied to the list of possible completions gener- + ated by the preceding options and arguments, and each + completion matching _f_i_l_t_e_r_p_a_t is removed from the list. + A leading !! in _f_i_l_t_e_r_p_a_t negates the pattern; in this + case, any completion not matching _f_i_l_t_e_r_p_a_t is removed. + --PP _p_r_e_f_i_x + _p_r_e_f_i_x is added at the beginning of each possible com- + pletion after all other options have been applied. + --SS _s_u_f_f_i_x + _s_u_f_f_i_x is appended to each possible completion after all + other options have been applied. + + The return value is true unless an invalid option is supplied, + an option other than --pp or --rr is supplied without a _n_a_m_e argu- + ment, an attempt is made to remove a completion specification + for a _n_a_m_e for which no specification exists, or an error occurs + adding a completion specification. + + ccoommppoopptt [--oo _o_p_t_i_o_n] [--DDEE] [++oo _o_p_t_i_o_n] [_n_a_m_e] + Modify completion options for each _n_a_m_e according to the + _o_p_t_i_o_ns, or for the currently-execution completion if no _n_a_m_es + are supplied. If no _o_p_t_i_o_ns are given, display the completion + options for each _n_a_m_e or the current completion. The possible + values of _o_p_t_i_o_n are those valid for the ccoommpplleettee builtin + described above. The --DD option indicates that the remaining + options should apply to the ``default'' command completion; that + is, completion attempted on a command for which no completion + has previously been defined. The --EE option indicates that the + remaining options should apply to ``empty'' command completion; + that is, completion attempted on a blank line. + + The return value is true unless an invalid option is supplied, an + attempt is made to modify the options for a _n_a_m_e for which no comple- + tion specification exists, or an output error occurs. + + ccoonnttiinnuuee [_n] + Resume the next iteration of the enclosing ffoorr, wwhhiillee, uunnttiill, or + sseelleecctt loop. If _n is specified, resume at the _nth enclosing + loop. _n must be >= 1. If _n is greater than the number of + enclosing loops, the last enclosing loop (the ``top-level'' + loop) is resumed. The return value is 0 unless _n is not greater + than or equal to 1. + + ddeeccllaarree [--aaAAffFFiillrrttuuxx] [--pp] [_n_a_m_e[=_v_a_l_u_e] ...] + ttyyppeesseett [--aaAAffFFiillrrttuuxx] [--pp] [_n_a_m_e[=_v_a_l_u_e] ...] + Declare variables and/or give them attributes. If no _n_a_m_es are + given then display the values of variables. The --pp option will + display the attributes and values of each _n_a_m_e. When --pp is used + with _n_a_m_e arguments, additional options are ignored. When --pp is + supplied without _n_a_m_e arguments, it will display the attributes + and values of all variables having the attributes specified by + the additional options. If no other options are supplied with + --pp, ddeeccllaarree will display the attributes and values of all shell + variables. The --ff option will restrict the display to shell + functions. The --FF option inhibits the display of function defi- + nitions; only the function name and attributes are printed. If + the eexxttddeebbuugg shell option is enabled using sshhoopptt, the source + file name and line number where the function is defined are dis- + played as well. The --FF option implies --ff. The following + options can be used to restrict output to variables with the + specified attribute or to give variables attributes: + --aa Each _n_a_m_e is an indexed array variable (see AArrrraayyss + above). + --AA Each _n_a_m_e is an associative array variable (see AArrrraayyss + above). + --ff Use function names only. + --ii The variable is treated as an integer; arithmetic evalua- + tion (see AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN above) is performed when + the variable is assigned a value. + --ll When the variable is assigned a value, all upper-case + characters are converted to lower-case. The upper-case + attribute is disabled. + --rr Make _n_a_m_es readonly. These names cannot then be assigned + values by subsequent assignment statements or unset. + --tt Give each _n_a_m_e the _t_r_a_c_e attribute. Traced functions + inherit the DDEEBBUUGG and RREETTUURRNN traps from the calling + shell. The trace attribute has no special meaning for + variables. + --uu When the variable is assigned a value, all lower-case + characters are converted to upper-case. The lower-case + attribute is disabled. + --xx Mark _n_a_m_es for export to subsequent commands via the + environment. + + Using `+' instead of `-' turns off the attribute instead, with + the exceptions that ++aa may not be used to destroy an array vari- + able and ++rr will not remove the readonly attribute. When used + in a function, makes each _n_a_m_e local, as with the llooccaall command. + If a variable name is followed by =_v_a_l_u_e, the value of the vari- + able is set to _v_a_l_u_e. The return value is 0 unless an invalid + option is encountered, an attempt is made to define a function + using ``-f foo=bar'', an attempt is made to assign a value to a + readonly variable, an attempt is made to assign a value to an + array variable without using the compound assignment syntax (see + AArrrraayyss above), one of the _n_a_m_e_s is not a valid shell variable + name, an attempt is made to turn off readonly status for a read- + only variable, an attempt is made to turn off array status for + an array variable, or an attempt is made to display a non-exis- + tent function with --ff. + + ddiirrss [[++_n]] [[--_n]] [[--ccppllvv]] + Without options, displays the list of currently remembered + directories. The default display is on a single line with + directory names separated by spaces. Directories are added to + the list with the ppuusshhdd command; the ppooppdd command removes + entries from the list. + ++_n Displays the _nth entry counting from the left of the list + shown by ddiirrss when invoked without options, starting with + zero. + --_n Displays the _nth entry counting from the right of the + list shown by ddiirrss when invoked without options, starting + with zero. + --cc Clears the directory stack by deleting all of the + entries. + --ll Produces a longer listing; the default listing format + uses a tilde to denote the home directory. + --pp Print the directory stack with one entry per line. + --vv Print the directory stack with one entry per line, pre- + fixing each entry with its index in the stack. + + The return value is 0 unless an invalid option is supplied or _n + indexes beyond the end of the directory stack. + + ddiissoowwnn [--aarr] [--hh] [_j_o_b_s_p_e_c ...] + Without options, each _j_o_b_s_p_e_c is removed from the table of + active jobs. If _j_o_b_s_p_e_c is not present, and neither --aa nor --rr + is supplied, the shell's notion of the _c_u_r_r_e_n_t _j_o_b is used. If + the --hh option is given, each _j_o_b_s_p_e_c is not removed from the ta- + ble, but is marked so that SSIIGGHHUUPP is not sent to the job if the + shell receives a SSIIGGHHUUPP. If no _j_o_b_s_p_e_c is present, and neither + the --aa nor the --rr option is supplied, the _c_u_r_r_e_n_t _j_o_b is used. + If no _j_o_b_s_p_e_c is supplied, the --aa option means to remove or mark + all jobs; the --rr option without a _j_o_b_s_p_e_c argument restricts + operation to running jobs. The return value is 0 unless a _j_o_b_- + _s_p_e_c does not specify a valid job. + + eecchhoo [--nneeEE] [_a_r_g ...] + Output the _a_r_gs, separated by spaces, followed by a newline. + The return status is always 0. If --nn is specified, the trailing + newline is suppressed. If the --ee option is given, interpreta- + tion of the following backslash-escaped characters is enabled. + The --EE option disables the interpretation of these escape char- + acters, even on systems where they are interpreted by default. + The xxppgg__eecchhoo shell option may be used to dynamically determine + whether or not eecchhoo expands these escape characters by default. + eecchhoo does not interpret ---- to mean the end of options. eecchhoo + interprets the following escape sequences: + \\aa alert (bell) + \\bb backspace + \\cc suppress further output + \\ee an escape character + \\ff form feed + \\nn new line + \\rr carriage return + \\tt horizontal tab + \\vv vertical tab + \\\\ backslash + \\00_n_n_n the eight-bit character whose value is the octal value + _n_n_n (zero to three octal digits) + \\xx_H_H the eight-bit character whose value is the hexadecimal + value _H_H (one or two hex digits) + + eennaabbllee [--aa] [--ddnnppss] [--ff _f_i_l_e_n_a_m_e] [_n_a_m_e ...] + Enable and disable builtin shell commands. Disabling a builtin + allows a disk command which has the same name as a shell builtin + to be executed without specifying a full pathname, even though + the shell normally searches for builtins before disk commands. + If --nn is used, each _n_a_m_e is disabled; otherwise, _n_a_m_e_s are + enabled. For example, to use the tteesstt binary found via the PPAATTHH + instead of the shell builtin version, run ``enable -n test''. + The --ff option means to load the new builtin command _n_a_m_e from + shared object _f_i_l_e_n_a_m_e, on systems that support dynamic loading. + The --dd option will delete a builtin previously loaded with --ff. + If no _n_a_m_e arguments are given, or if the --pp option is supplied, + a list of shell builtins is printed. With no other option argu- + ments, the list consists of all enabled shell builtins. If --nn + is supplied, only disabled builtins are printed. If --aa is sup- + plied, the list printed includes all builtins, with an indica- + tion of whether or not each is enabled. If --ss is supplied, the + output is restricted to the POSIX _s_p_e_c_i_a_l builtins. The return + value is 0 unless a _n_a_m_e is not a shell builtin or there is an + error loading a new builtin from a shared object. + + eevvaall [_a_r_g ...] + The _a_r_gs are read and concatenated together into a single com- + mand. This command is then read and executed by the shell, and + its exit status is returned as the value of eevvaall. If there are + no _a_r_g_s, or only null arguments, eevvaall returns 0. + + eexxeecc [--ccll] [--aa _n_a_m_e] [_c_o_m_m_a_n_d [_a_r_g_u_m_e_n_t_s]] + If _c_o_m_m_a_n_d is specified, it replaces the shell. No new process + is created. The _a_r_g_u_m_e_n_t_s become the arguments to _c_o_m_m_a_n_d. If + the --ll option is supplied, the shell places a dash at the begin- + ning of the zeroth argument passed to _c_o_m_m_a_n_d. This is what + _l_o_g_i_n(1) does. The --cc option causes _c_o_m_m_a_n_d to be executed with + an empty environment. If --aa is supplied, the shell passes _n_a_m_e + as the zeroth argument to the executed command. If _c_o_m_m_a_n_d can- + not be executed for some reason, a non-interactive shell exits, + unless the shell option eexxeeccffaaiill is enabled, in which case it + returns failure. An interactive shell returns failure if the + file cannot be executed. If _c_o_m_m_a_n_d is not specified, any redi- + rections take effect in the current shell, and the return status + is 0. If there is a redirection error, the return status is 1. + + eexxiitt [_n] + Cause the shell to exit with a status of _n. If _n is omitted, + the exit status is that of the last command executed. A trap on + EEXXIITT is executed before the shell terminates. + + eexxppoorrtt [--ffnn] [_n_a_m_e[=_w_o_r_d]] ... + eexxppoorrtt --pp + The supplied _n_a_m_e_s are marked for automatic export to the envi- + ronment of subsequently executed commands. If the --ff option is + given, the _n_a_m_e_s refer to functions. If no _n_a_m_e_s are given, or + if the --pp option is supplied, a list of all names that are + exported in this shell is printed. The --nn option causes the + export property to be removed from each _n_a_m_e. If a variable + name is followed by =_w_o_r_d, the value of the variable is set to + _w_o_r_d. eexxppoorrtt returns an exit status of 0 unless an invalid + option is encountered, one of the _n_a_m_e_s is not a valid shell + variable name, or --ff is supplied with a _n_a_m_e that is not a func- + tion. + + ffcc [--ee _e_n_a_m_e] [--llnnrr] [_f_i_r_s_t] [_l_a_s_t] + ffcc --ss [_p_a_t=_r_e_p] [_c_m_d] + Fix Command. In the first form, a range of commands from _f_i_r_s_t + to _l_a_s_t is selected from the history list. _F_i_r_s_t and _l_a_s_t may + be specified as a string (to locate the last command beginning + with that string) or as a number (an index into the history + list, where a negative number is used as an offset from the cur- + rent command number). If _l_a_s_t is not specified it is set to the + current command for listing (so that ``fc -l -10'' prints the + last 10 commands) and to _f_i_r_s_t otherwise. If _f_i_r_s_t is not spec- + ified it is set to the previous command for editing and -16 for + listing. + + The --nn option suppresses the command numbers when listing. The + --rr option reverses the order of the commands. If the --ll option + is given, the commands are listed on standard output. Other- + wise, the editor given by _e_n_a_m_e is invoked on a file containing + those commands. If _e_n_a_m_e is not given, the value of the FFCCEEDDIITT + variable is used, and the value of EEDDIITTOORR if FFCCEEDDIITT is not set. + If neither variable is set, is used. When editing is complete, + the edited commands are echoed and executed. + + In the second form, _c_o_m_m_a_n_d is re-executed after each instance + of _p_a_t is replaced by _r_e_p. A useful alias to use with this is + ``r="fc -s"'', so that typing ``r cc'' runs the last command + beginning with ``cc'' and typing ``r'' re-executes the last com- + mand. + + If the first form is used, the return value is 0 unless an + invalid option is encountered or _f_i_r_s_t or _l_a_s_t specify history + lines out of range. If the --ee option is supplied, the return + value is the value of the last command executed or failure if an + error occurs with the temporary file of commands. If the second + form is used, the return status is that of the command re-exe- + cuted, unless _c_m_d does not specify a valid history line, in + which case ffcc returns failure. + + ffgg [_j_o_b_s_p_e_c] + Resume _j_o_b_s_p_e_c in the foreground, and make it the current job. + If _j_o_b_s_p_e_c is not present, the shell's notion of the _c_u_r_r_e_n_t _j_o_b + is used. The return value is that of the command placed into + the foreground, or failure if run when job control is disabled + or, when run with job control enabled, if _j_o_b_s_p_e_c does not spec- + ify a valid job or _j_o_b_s_p_e_c specifies a job that was started + without job control. + + ggeettooppttss _o_p_t_s_t_r_i_n_g _n_a_m_e [_a_r_g_s] + ggeettooppttss is used by shell procedures to parse positional parame- + ters. _o_p_t_s_t_r_i_n_g contains the option characters to be recog- + nized; if a character is followed by a colon, the option is + expected to have an argument, which should be separated from it + by white space. The colon and question mark characters may not + be used as option characters. Each time it is invoked, ggeettooppttss + places the next option in the shell variable _n_a_m_e, initializing + _n_a_m_e if it does not exist, and the index of the next argument to + be processed into the variable OOPPTTIINNDD. OOPPTTIINNDD is initialized to + 1 each time the shell or a shell script is invoked. When an + option requires an argument, ggeettooppttss places that argument into + the variable OOPPTTAARRGG. The shell does not reset OOPPTTIINNDD automati- + cally; it must be manually reset between multiple calls to + ggeettooppttss within the same shell invocation if a new set of parame- + ters is to be used. + + When the end of options is encountered, ggeettooppttss exits with a + return value greater than zero. OOPPTTIINNDD is set to the index of + the first non-option argument, and nnaammee is set to ?. + + ggeettooppttss normally parses the positional parameters, but if more + arguments are given in _a_r_g_s, ggeettooppttss parses those instead. + + ggeettooppttss can report errors in two ways. If the first character + of _o_p_t_s_t_r_i_n_g is a colon, _s_i_l_e_n_t error reporting is used. In + normal operation diagnostic messages are printed when invalid + options or missing option arguments are encountered. If the + variable OOPPTTEERRRR is set to 0, no error messages will be dis- + played, even if the first character of _o_p_t_s_t_r_i_n_g is not a colon. + + If an invalid option is seen, ggeettooppttss places ? into _n_a_m_e and, if + not silent, prints an error message and unsets OOPPTTAARRGG. If + ggeettooppttss is silent, the option character found is placed in + OOPPTTAARRGG and no diagnostic message is printed. + + If a required argument is not found, and ggeettooppttss is not silent, + a question mark (??) is placed in _n_a_m_e, OOPPTTAARRGG is unset, and a + diagnostic message is printed. If ggeettooppttss is silent, then a + colon (::) is placed in _n_a_m_e and OOPPTTAARRGG is set to the option + character found. + + ggeettooppttss returns true if an option, specified or unspecified, is + found. It returns false if the end of options is encountered or + an error occurs. + + hhaasshh [--llrr] [--pp _f_i_l_e_n_a_m_e] [--ddtt] [_n_a_m_e] + For each _n_a_m_e, the full file name of the command is determined + by searching the directories in $$PPAATTHH and remembered. If the --pp + option is supplied, no path search is performed, and _f_i_l_e_n_a_m_e is + used as the full file name of the command. The --rr option causes + the shell to forget all remembered locations. The --dd option + causes the shell to forget the remembered location of each _n_a_m_e. + If the --tt option is supplied, the full pathname to which each + _n_a_m_e corresponds is printed. If multiple _n_a_m_e arguments are + supplied with --tt, the _n_a_m_e is printed before the hashed full + pathname. The --ll option causes output to be displayed in a for- + mat that may be reused as input. If no arguments are given, or + if only --ll is supplied, information about remembered commands is + printed. The return status is true unless a _n_a_m_e is not found + or an invalid option is supplied. + + hheellpp [--ddmmss] [_p_a_t_t_e_r_n] + Display helpful information about builtin commands. If _p_a_t_t_e_r_n + is specified, hheellpp gives detailed help on all commands matching + _p_a_t_t_e_r_n; otherwise help for all the builtins and shell control + structures is printed. + --dd Display a short description of each _p_a_t_t_e_r_n + --mm Display the description of each _p_a_t_t_e_r_n in a manpage-like + format + --ss Display only a short usage synopsis for each _p_a_t_t_e_r_n + The return status is 0 unless no command matches _p_a_t_t_e_r_n. + + hhiissttoorryy [[_n]] + hhiissttoorryy --cc + hhiissttoorryy --dd _o_f_f_s_e_t + hhiissttoorryy --aannrrww [_f_i_l_e_n_a_m_e] + hhiissttoorryy --pp _a_r_g [_a_r_g _._._.] + hhiissttoorryy --ss _a_r_g [_a_r_g _._._.] + With no options, display the command history list with line num- + bers. Lines listed with a ** have been modified. An argument of + _n lists only the last _n lines. If the shell variable HHIISSTTTTIIMMEE-- + FFOORRMMAATT is set and not null, it is used as a format string for + _s_t_r_f_t_i_m_e(3) to display the time stamp associated with each dis- + played history entry. No intervening blank is printed between + the formatted time stamp and the history line. If _f_i_l_e_n_a_m_e is + supplied, it is used as the name of the history file; if not, + the value of HHIISSTTFFIILLEE is used. Options, if supplied, have the + following meanings: + --cc Clear the history list by deleting all the entries. + --dd _o_f_f_s_e_t + Delete the history entry at position _o_f_f_s_e_t. + --aa Append the ``new'' history lines (history lines entered + since the beginning of the current bbaasshh session) to the + history file. + --nn Read the history lines not already read from the history + file into the current history list. These are lines + appended to the history file since the beginning of the + current bbaasshh session. + --rr Read the contents of the history file and use them as the + current history. + --ww Write the current history to the history file, overwrit- + ing the history file's contents. + --pp Perform history substitution on the following _a_r_g_s and + display the result on the standard output. Does not + store the results in the history list. Each _a_r_g must be + quoted to disable normal history expansion. + --ss Store the _a_r_g_s in the history list as a single entry. + The last command in the history list is removed before + the _a_r_g_s are added. + + If the HHIISSTTTTIIMMEEFFOORRMMAATT variable is set, the time stamp informa- + tion associated with each history entry is written to the his- + tory file, marked with the history comment character. When the + history file is read, lines beginning with the history comment + character followed immediately by a digit are interpreted as + timestamps for the previous history line. The return value is 0 + unless an invalid option is encountered, an error occurs while + reading or writing the history file, an invalid _o_f_f_s_e_t is sup- + plied as an argument to --dd, or the history expansion supplied as + an argument to --pp fails. + + jjoobbss [--llnnpprrss] [ _j_o_b_s_p_e_c ... ] + jjoobbss --xx _c_o_m_m_a_n_d [ _a_r_g_s ... ] + The first form lists the active jobs. The options have the fol- + lowing meanings: + --ll List process IDs in addition to the normal information. + --pp List only the process ID of the job's process group + leader. + --nn Display information only about jobs that have changed + status since the user was last notified of their status. + --rr Restrict output to running jobs. + --ss Restrict output to stopped jobs. + + If _j_o_b_s_p_e_c is given, output is restricted to information about + that job. The return status is 0 unless an invalid option is + encountered or an invalid _j_o_b_s_p_e_c is supplied. + + If the --xx option is supplied, jjoobbss replaces any _j_o_b_s_p_e_c found in + _c_o_m_m_a_n_d or _a_r_g_s with the corresponding process group ID, and + executes _c_o_m_m_a_n_d passing it _a_r_g_s, returning its exit status. + + kkiillll [--ss _s_i_g_s_p_e_c | --nn _s_i_g_n_u_m | --_s_i_g_s_p_e_c] [_p_i_d | _j_o_b_s_p_e_c] ... + kkiillll --ll [_s_i_g_s_p_e_c | _e_x_i_t___s_t_a_t_u_s] + Send the signal named by _s_i_g_s_p_e_c or _s_i_g_n_u_m to the processes + named by _p_i_d or _j_o_b_s_p_e_c. _s_i_g_s_p_e_c is either a case-insensitive + signal name such as SSIIGGKKIILLLL (with or without the SSIIGG prefix) or + a signal number; _s_i_g_n_u_m is a signal number. If _s_i_g_s_p_e_c is not + present, then SSIIGGTTEERRMM is assumed. An argument of --ll lists the + signal names. If any arguments are supplied when --ll is given, + the names of the signals corresponding to the arguments are + listed, and the return status is 0. The _e_x_i_t___s_t_a_t_u_s argument to + --ll is a number specifying either a signal number or the exit + status of a process terminated by a signal. kkiillll returns true + if at least one signal was successfully sent, or false if an + error occurs or an invalid option is encountered. + + lleett _a_r_g [_a_r_g ...] + Each _a_r_g is an arithmetic expression to be evaluated (see AARRIITTHH-- + MMEETTIICC EEVVAALLUUAATTIIOONN above). If the last _a_r_g evaluates to 0, lleett + returns 1; 0 is returned otherwise. + + llooccaall [_o_p_t_i_o_n] [_n_a_m_e[=_v_a_l_u_e] ...] + For each argument, a local variable named _n_a_m_e is created, and + assigned _v_a_l_u_e. The _o_p_t_i_o_n can be any of the options accepted + by ddeeccllaarree. When llooccaall is used within a function, it causes the + variable _n_a_m_e to have a visible scope restricted to that func- + tion and its children. With no operands, llooccaall writes a list of + local variables to the standard output. It is an error to use + llooccaall when not within a function. The return status is 0 unless + llooccaall is used outside a function, an invalid _n_a_m_e is supplied, + or _n_a_m_e is a readonly variable. + + llooggoouutt Exit a login shell. + + mmaappffiillee [--nn _c_o_u_n_t] [--OO _o_r_i_g_i_n] [--ss _c_o_u_n_t] [--tt] [--uu _f_d] [--CC _c_a_l_l_b_a_c_k] + [--cc _q_u_a_n_t_u_m] [_a_r_r_a_y] + rreeaaddaarrrraayy [--nn _c_o_u_n_t] [--OO _o_r_i_g_i_n] [--ss _c_o_u_n_t] [--tt] [--uu _f_d] [--CC _c_a_l_l_b_a_c_k] + [--cc _q_u_a_n_t_u_m] [_a_r_r_a_y] + Read lines from the standard input into the indexed array vari- + able _a_r_r_a_y, or from file descriptor _f_d if the --uu option is sup- + plied. The variable MMAAPPFFIILLEE is the default _a_r_r_a_y. Options, if + supplied, have the following meanings: + --nn Copy at most _c_o_u_n_t lines. If _c_o_u_n_t is 0, all lines are + copied. + --OO Begin assigning to _a_r_r_a_y at index _o_r_i_g_i_n. The default + index is 0. + --ss Discard the first _c_o_u_n_t lines read. + --tt Remove a trailing newline from each line read. + --uu Read lines from file descriptor _f_d instead of the stan- + dard input. + --CC Evaluate _c_a_l_l_b_a_c_k each time _q_u_a_n_t_u_m lines are read. The + --cc option specifies _q_u_a_n_t_u_m. + --cc Specify the number of lines read between each call to + _c_a_l_l_b_a_c_k. + + If --CC is specified without --cc, the default quantum is 5000. + When _c_a_l_l_b_a_c_k is evaluated, it is supplied the index of the next + array element to be assigned as an additional argument. _c_a_l_l_- + _b_a_c_k is evaluated after the line is read but before the array + element is assigned. + + If not supplied with an explicit origin, mmaappffiillee will clear + _a_r_r_a_y before assigning to it. + + mmaappffiillee returns successfully unless an invalid option or option + argument is supplied, _a_r_r_a_y is invalid or unassignable, or if + _a_r_r_a_y is not an indexed array. + + ppooppdd [-nn] [+_n] [-_n] + Removes entries from the directory stack. With no arguments, + removes the top directory from the stack, and performs a ccdd to + the new top directory. Arguments, if supplied, have the follow- + ing meanings: + --nn Suppresses the normal change of directory when removing + directories from the stack, so that only the stack is + manipulated. + ++_n Removes the _nth entry counting from the left of the list + shown by ddiirrss, starting with zero. For example: ``popd + +0'' removes the first directory, ``popd +1'' the second. + --_n Removes the _nth entry counting from the right of the list + shown by ddiirrss, starting with zero. For example: ``popd + -0'' removes the last directory, ``popd -1'' the next to + last. + + If the ppooppdd command is successful, a ddiirrss is performed as well, + and the return status is 0. ppooppdd returns false if an invalid + option is encountered, the directory stack is empty, a non-exis- + tent directory stack entry is specified, or the directory change + fails. + + pprriinnttff [--vv _v_a_r] _f_o_r_m_a_t [_a_r_g_u_m_e_n_t_s] + Write the formatted _a_r_g_u_m_e_n_t_s to the standard output under the + control of the _f_o_r_m_a_t. The _f_o_r_m_a_t is a character string which + contains three types of objects: plain characters, which are + simply copied to standard output, character escape sequences, + which are converted and copied to the standard output, and for- + mat specifications, each of which causes printing of the next + successive _a_r_g_u_m_e_n_t. In addition to the standard _p_r_i_n_t_f(1) for- + mats, %%bb causes pprriinnttff to expand backslash escape sequences in + the corresponding _a_r_g_u_m_e_n_t (except that \\cc terminates output, + backslashes in \\'', \\"", and \\?? are not removed, and octal escapes + beginning with \\00 may contain up to four digits), and %%qq causes + pprriinnttff to output the corresponding _a_r_g_u_m_e_n_t in a format that can + be reused as shell input. + + The --vv option causes the output to be assigned to the variable + _v_a_r rather than being printed to the standard output. + + The _f_o_r_m_a_t is reused as necessary to consume all of the _a_r_g_u_- + _m_e_n_t_s. If the _f_o_r_m_a_t requires more _a_r_g_u_m_e_n_t_s than are supplied, + the extra format specifications behave as if a zero value or + null string, as appropriate, had been supplied. The return + value is zero on success, non-zero on failure. + + ppuusshhdd [--nn] [+_n] [-_n] + ppuusshhdd [--nn] [_d_i_r] + Adds a directory to the top of the directory stack, or rotates + the stack, making the new top of the stack the current working + directory. With no arguments, exchanges the top two directories + and returns 0, unless the directory stack is empty. Arguments, + if supplied, have the following meanings: + --nn Suppresses the normal change of directory when adding + directories to the stack, so that only the stack is + manipulated. + ++_n Rotates the stack so that the _nth directory (counting + from the left of the list shown by ddiirrss, starting with + zero) is at the top. + --_n Rotates the stack so that the _nth directory (counting + from the right of the list shown by ddiirrss, starting with + zero) is at the top. + _d_i_r Adds _d_i_r to the directory stack at the top, making it the + new current working directory. + + If the ppuusshhdd command is successful, a ddiirrss is performed as well. + If the first form is used, ppuusshhdd returns 0 unless the cd to _d_i_r + fails. With the second form, ppuusshhdd returns 0 unless the direc- + tory stack is empty, a non-existent directory stack element is + specified, or the directory change to the specified new current + directory fails. + + ppwwdd [--LLPP] + Print the absolute pathname of the current working directory. + The pathname printed contains no symbolic links if the --PP option + is supplied or the --oo pphhyyssiiccaall option to the sseett builtin command + is enabled. If the --LL option is used, the pathname printed may + contain symbolic links. The return status is 0 unless an error + occurs while reading the name of the current directory or an + invalid option is supplied. + + rreeaadd [--eerrss] [--aa _a_n_a_m_e] [--dd _d_e_l_i_m] [--ii _t_e_x_t] [--nn _n_c_h_a_r_s] [--NN _n_c_h_a_r_s] [--pp + _p_r_o_m_p_t] [--tt _t_i_m_e_o_u_t] [--uu _f_d] [_n_a_m_e ...] + One line is read from the standard input, or from the file + descriptor _f_d supplied as an argument to the --uu option, and the + first word is assigned to the first _n_a_m_e, the second word to the + second _n_a_m_e, and so on, with leftover words and their interven- + ing separators assigned to the last _n_a_m_e. If there are fewer + words read from the input stream than names, the remaining names + are assigned empty values. The characters in IIFFSS are used to + split the line into words. The backslash character (\\) may be + used to remove any special meaning for the next character read + and for line continuation. Options, if supplied, have the fol- + lowing meanings: + --aa _a_n_a_m_e + The words are assigned to sequential indices of the array + variable _a_n_a_m_e, starting at 0. _a_n_a_m_e is unset before any + new values are assigned. Other _n_a_m_e arguments are + ignored. + --dd _d_e_l_i_m + The first character of _d_e_l_i_m is used to terminate the + input line, rather than newline. + --ee If the standard input is coming from a terminal, rreeaaddlliinnee + (see RREEAADDLLIINNEE above) is used to obtain the line. Read- + line uses the current (or default, if line editing was + not previously active) editing settings. + --ii _t_e_x_t + If rreeaaddlliinnee is being used to read the line, _t_e_x_t is + placed into the editing buffer before editing begins. + --nn _n_c_h_a_r_s + rreeaadd returns after reading _n_c_h_a_r_s characters rather than + waiting for a complete line of input, but honor a delim- + iter if fewer than _n_c_h_a_r_s characters are read before the + delimiter. + --NN _n_c_h_a_r_s + rreeaadd returns after reading exactly _n_c_h_a_r_s characters + rather than waiting for a complete line of input, unless + EOF is encountered or rreeaadd times out. Delimiter charac- + ters encountered in the input are not treated specially + and do not cause rreeaadd to return until _n_c_h_a_r_s characters + are read. + --pp _p_r_o_m_p_t + Display _p_r_o_m_p_t on standard error, without a trailing new- + line, before attempting to read any input. The prompt is + displayed only if input is coming from a terminal. + --rr Backslash does not act as an escape character. The back- + slash is considered to be part of the line. In particu- + lar, a backslash-newline pair may not be used as a line + continuation. + --ss Silent mode. If input is coming from a terminal, charac- + ters are not echoed. + --tt _t_i_m_e_o_u_t + Cause rreeaadd to time out and return failure if a complete + line of input is not read within _t_i_m_e_o_u_t seconds. _t_i_m_e_- + _o_u_t may be a decimal number with a fractional portion + following the decimal point. This option is only effec- + tive if rreeaadd is reading input from a terminal, pipe, or + other special file; it has no effect when reading from + regular files. If _t_i_m_e_o_u_t is 0, rreeaadd returns success if + input is available on the specified file descriptor, + failure otherwise. The exit status is greater than 128 + if the timeout is exceeded. + --uu _f_d Read input from file descriptor _f_d. + + If no _n_a_m_e_s are supplied, the line read is assigned to the vari- + able RREEPPLLYY. The return code is zero, unless end-of-file is + encountered, rreeaadd times out (in which case the return code is + greater than 128), or an invalid file descriptor is supplied as + the argument to --uu. + + rreeaaddoonnllyy [--aaAAppff] [_n_a_m_e[=_w_o_r_d] ...] + The given _n_a_m_e_s are marked readonly; the values of these _n_a_m_e_s + may not be changed by subsequent assignment. If the --ff option + is supplied, the functions corresponding to the _n_a_m_e_s are so + marked. The --aa option restricts the variables to indexed + arrays; the --AA option restricts the variables to associative + arrays. If no _n_a_m_e arguments are given, or if the --pp option is + supplied, a list of all readonly names is printed. The --pp + option causes output to be displayed in a format that may be + reused as input. If a variable name is followed by =_w_o_r_d, the + value of the variable is set to _w_o_r_d. The return status is 0 + unless an invalid option is encountered, one of the _n_a_m_e_s is not + a valid shell variable name, or --ff is supplied with a _n_a_m_e that + is not a function. + + rreettuurrnn [_n] + Causes a function to exit with the return value specified by _n. + If _n is omitted, the return status is that of the last command + executed in the function body. If used outside a function, but + during execution of a script by the .. (ssoouurrccee) command, it + causes the shell to stop executing that script and return either + _n or the exit status of the last command executed within the + script as the exit status of the script. If used outside a + function and not during execution of a script by .., the return + status is false. Any command associated with the RREETTUURRNN trap is + executed before execution resumes after the function or script. + + sseett [----aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [--oo _o_p_t_i_o_n] [_a_r_g ...] + sseett [++aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [++oo _o_p_t_i_o_n] [_a_r_g ...] + Without options, the name and value of each shell variable are + displayed in a format that can be reused as input for setting or + resetting the currently-set variables. Read-only variables can- + not be reset. In _p_o_s_i_x _m_o_d_e, only shell variables are listed. + The output is sorted according to the current locale. When + options are specified, they set or unset shell attributes. Any + arguments remaining after option processing are treated as val- + ues for the positional parameters and are assigned, in order, to + $$11, $$22, ...... $$_n. Options, if specified, have the following + meanings: + --aa Automatically mark variables and functions which are + modified or created for export to the environment of + subsequent commands. + --bb Report the status of terminated background jobs immedi- + ately, rather than before the next primary prompt. This + is effective only when job control is enabled. + --ee Exit immediately if a _p_i_p_e_l_i_n_e (which may consist of a + single _s_i_m_p_l_e _c_o_m_m_a_n_d), a _s_u_b_s_h_e_l_l command enclosed in + parentheses, or one of the commands executed as part of + a command list enclosed by braces (see SSHHEELLLL GGRRAAMMMMAARR + above) exits with a non-zero status. The shell does not + exit if the command that fails is part of the command + list immediately following a wwhhiillee or uunnttiill keyword, + part of the test following the iiff or eelliiff reserved + words, part of any 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 with !!. A trap on EERRRR, + if set, is executed before the shell exits. This option + applies to the shell environment and each subshell envi- + ronment separately (see CCOOMMMMAANNDD EEXXEECCUUTTIIOONN EENNVVIIRROONNMMEENNTT + above), and may cause subshells to exit before executing + all the commands in the subshell. + --ff Disable pathname expansion. + --hh Remember the location of commands as they are looked up + for execution. This is enabled by default. + --kk All arguments in the form of assignment statements are + placed in the environment for a command, not just those + that precede the command name. + --mm Monitor mode. Job control is enabled. This option is + on by default for interactive shells on systems that + support it (see JJOOBB CCOONNTTRROOLL above). Background pro- + cesses run in a separate process group and a line con- + taining their exit status is printed upon their comple- + tion. + --nn Read commands but do not execute them. This may be used + to check a shell script for syntax errors. This is + ignored by interactive shells. + --oo _o_p_t_i_o_n_-_n_a_m_e + The _o_p_t_i_o_n_-_n_a_m_e can be one of the following: + aalllleexxppoorrtt + Same as --aa. + bbrraacceeeexxppaanndd + Same as --BB. + eemmaaccss Use an emacs-style command line editing inter- + face. This is enabled by default when the shell + is interactive, unless the shell is started with + the ----nnooeeddiittiinngg option. This also affects the + editing interface used for rreeaadd --ee. + eerrrreexxiitt Same as --ee. + eerrrrttrraaccee + Same as --EE. + ffuunnccttrraaccee + Same as --TT. + hhaasshhaallll Same as --hh. + hhiisstteexxppaanndd + Same as --HH. + hhiissttoorryy Enable command history, as described above under + HHIISSTTOORRYY. This option is on by default in inter- + active shells. + iiggnnoorreeeeooff + The effect is as if the shell command + ``IGNOREEOF=10'' had been executed (see SShheellll + VVaarriiaabblleess above). + kkeeyywwoorrdd Same as --kk. + mmoonniittoorr Same as --mm. + nnoocclloobbbbeerr + Same as --CC. + nnooeexxeecc Same as --nn. + nnoogglloobb Same as --ff. + nnoolloogg Currently ignored. + nnoottiiffyy Same as --bb. + nnoouunnsseett Same as --uu. + oonneeccmmdd Same as --tt. + pphhyyssiiccaall + Same as --PP. + ppiippeeffaaiill + If set, the return value of a pipeline is the + value of the last (rightmost) command to exit + with a non-zero status, or zero if all commands + in the pipeline exit successfully. This option + is disabled by default. + ppoossiixx Change the behavior of bbaasshh where the default + operation differs from the POSIX standard to + match the standard (_p_o_s_i_x _m_o_d_e). + pprriivviilleeggeedd + Same as --pp. + vveerrbboossee Same as --vv. + vvii Use a vi-style command line editing interface. + This also affects the editing interface used for + rreeaadd --ee. + xxttrraaccee Same as --xx. + If --oo is supplied with no _o_p_t_i_o_n_-_n_a_m_e, the values of the + current options are printed. If ++oo is supplied with no + _o_p_t_i_o_n_-_n_a_m_e, a series of sseett commands to recreate the + current option settings is displayed on the standard + output. + --pp Turn on _p_r_i_v_i_l_e_g_e_d mode. In this mode, the $$EENNVV and + $$BBAASSHH__EENNVV files are not processed, shell functions are + not inherited from the environment, and the SSHHEELLLLOOPPTTSS, + BBAASSHHOOPPTTSS, CCDDPPAATTHH, and GGLLOOBBIIGGNNOORREE variables, if they + appear in the environment, are ignored. If the shell is + started with the effective user (group) id not equal to + the real user (group) id, and the --pp option is not sup- + plied, these actions are taken and the effective user id + is set to the real user id. If the --pp option is sup- + plied at startup, the effective user id is not reset. + Turning this option off causes the effective user and + group ids to be set to the real user and group ids. + --tt Exit after reading and executing one command. + --uu Treat unset variables and parameters other than the spe- + cial parameters "@" and "*" as an error when performing + parameter expansion. If expansion is attempted on an + unset variable or parameter, the shell prints an error + message, and, if not interactive, exits with a non-zero + status. + --vv Print shell input lines as they are read. + --xx After expanding each _s_i_m_p_l_e _c_o_m_m_a_n_d, ffoorr command, ccaassee + command, sseelleecctt command, or arithmetic ffoorr command, dis- + play the expanded value of PPSS44, followed by the command + and its expanded arguments or associated word list. + --BB The shell performs brace expansion (see BBrraaccee EExxppaannssiioonn + above). This is on by default. + --CC If set, bbaasshh does not overwrite an existing file with + the >>, >>&&, and <<>> redirection operators. This may be + overridden when creating output files by using the redi- + rection operator >>|| instead of >>. + --EE If set, any trap on EERRRR is inherited by shell functions, + command substitutions, and commands executed in a sub- + shell environment. The EERRRR trap is normally not inher- + ited in such cases. + --HH Enable !! style history substitution. This option is on + by default when the shell is interactive. + --PP If set, the shell does not follow symbolic links when + executing commands such as ccdd that change the current + working directory. It uses the physical directory + structure instead. By default, bbaasshh follows the logical + chain of directories when performing commands which + change the current directory. + --TT If set, any traps on DDEEBBUUGG and RREETTUURRNN are inherited by + shell functions, command substitutions, and commands + executed in a subshell environment. The DDEEBBUUGG and + RREETTUURRNN traps are normally not inherited in such cases. + ---- If no arguments follow this option, then the positional + parameters are unset. Otherwise, the positional parame- + ters are set to the _a_r_gs, even if some of them begin + with a --. + -- Signal the end of options, cause all remaining _a_r_gs to + be assigned to the positional parameters. The --xx and --vv + options are turned off. If there are no _a_r_gs, the posi- + tional parameters remain unchanged. + + The options are off by default unless otherwise noted. Using + + rather than - causes these options to be turned off. The + options can also be specified as arguments to an invocation of + the shell. The current set of options may be found in $$--. The + return status is always true unless an invalid option is encoun- + tered. + + sshhiifftt [_n] + The positional parameters from _n+1 ... are renamed to $$11 ........ + Parameters represented by the numbers $$## down to $$##-_n+1 are + unset. _n must be a non-negative number less than or equal to + $$##. If _n is 0, no parameters are changed. If _n is not given, + it is assumed to be 1. If _n is greater than $$##, the positional + parameters are not changed. The return status is greater than + zero if _n is greater than $$## or less than zero; otherwise 0. + + sshhoopptt [--ppqqssuu] [--oo] [_o_p_t_n_a_m_e ...] + Toggle the values of variables controlling optional shell behav- + ior. With no options, or with the --pp option, a list of all set- + table options is displayed, with an indication of whether or not + each is set. The --pp option causes output to be displayed in a + form that may be reused as input. Other options have the fol- + lowing meanings: + --ss Enable (set) each _o_p_t_n_a_m_e. + --uu Disable (unset) each _o_p_t_n_a_m_e. + --qq Suppresses normal output (quiet mode); the return status + indicates whether the _o_p_t_n_a_m_e is set or unset. If multi- + ple _o_p_t_n_a_m_e arguments are given with --qq, the return sta- + tus is zero if all _o_p_t_n_a_m_e_s are enabled; non-zero other- + wise. + --oo Restricts the values of _o_p_t_n_a_m_e to be those defined for + the --oo option to the sseett builtin. + + If either --ss or --uu is used with no _o_p_t_n_a_m_e arguments, the dis- + play is limited to those options which are set or unset, respec- + tively. Unless otherwise noted, the sshhoopptt options are disabled + (unset) by default. + + The return status when listing options is zero if all _o_p_t_n_a_m_e_s + are enabled, non-zero otherwise. When setting or unsetting + options, the return status is zero unless an _o_p_t_n_a_m_e is not a + valid shell option. + + The list of sshhoopptt options is: + + aauuttooccdd If set, a command name that is the name of a directory + is executed as if it were the argument to the ccdd com- + mand. This option is only used by interactive shells. + ccddaabbllee__vvaarrss + If set, an argument to the ccdd builtin command that is + not a directory is assumed to be the name of a variable + whose value is the directory to change to. + ccddssppeellll If set, minor errors in the spelling of a directory com- + ponent in a ccdd command will be corrected. The errors + checked for are transposed characters, a missing charac- + ter, and one character too many. If a correction is + found, the corrected file name is printed, and the com- + mand proceeds. This option is only used by interactive + shells. + cchheecckkhhaasshh + If set, bbaasshh checks that a command found in the hash ta- + ble exists before trying to execute it. If a hashed + command no longer exists, a normal path search is per- + formed. + cchheecckkjjoobbss + If set, bbaasshh lists the status of any stopped and running + jobs before exiting an interactive shell. If any jobs + are running, this causes the exit to be deferred until a + second exit is attempted without an intervening command + (see JJOOBB CCOONNTTRROOLL above). The shell always postpones + exiting if any jobs are stopped. + cchheecckkwwiinnssiizzee + If set, bbaasshh checks the window size after each command + and, if necessary, updates the values of LLIINNEESS and CCOOLL-- + UUMMNNSS. + ccmmddhhiisstt If set, bbaasshh attempts to save all lines of a multiple- + line command in the same history entry. This allows + easy re-editing of multi-line commands. + ccoommppaatt3311 + If set, bbaasshh changes its behavior to that of version 3.1 + with respect to quoted arguments to the conditional com- + mand's =~ operator. + ccoommppaatt3322 + If set, bbaasshh changes its behavior to that of version 3.2 + with respect to locale-specific string comparison when + using the conditional command's < and > operators. + ccoommppaatt4400 + If set, bbaasshh changes its behavior to that of version 4.0 + with respect to locale-specific string comparison when + using the conditional command's < and > operators and + the effect of interrupting a command list. + ddiirrssppeellll + If set, bbaasshh attempts spelling correction on directory + names during word completion if the directory name ini- + tially supplied does not exist. + ddoottgglloobb If set, bbaasshh includes filenames beginning with a `.' in + the results of pathname expansion. + eexxeeccffaaiill + If set, a non-interactive shell will not exit if it can- + not execute the file specified as an argument to the + eexxeecc builtin command. An interactive shell does not + exit if eexxeecc fails. + eexxppaanndd__aalliiaasseess + If set, aliases are expanded as described above under + AALLIIAASSEESS. This option is enabled by default for interac- + tive shells. + eexxttddeebbuugg + If set, behavior intended for use by debuggers is + enabled: + 11.. The --FF option to the ddeeccllaarree builtin displays the + source file name and line number corresponding to + each function name supplied as an argument. + 22.. If the command run by the DDEEBBUUGG trap returns a + non-zero value, the next command is skipped and + not executed. + 33.. If the command run by the DDEEBBUUGG trap returns a + value of 2, and the shell is executing in a sub- + routine (a shell function or a shell script exe- + cuted by the .. or ssoouurrccee builtins), a call to + rreettuurrnn is simulated. + 44.. BBAASSHH__AARRGGCC and BBAASSHH__AARRGGVV are updated as described + in their descriptions above. + 55.. Function tracing is enabled: command substitu- + tion, shell functions, and subshells invoked with + (( _c_o_m_m_a_n_d )) inherit the DDEEBBUUGG and RREETTUURRNN traps. + 66.. Error tracing is enabled: command substitution, + shell functions, and subshells invoked with (( + _c_o_m_m_a_n_d )) inherit the EERRRROORR trap. + eexxttgglloobb If set, the extended pattern matching features described + above under PPaatthhnnaammee EExxppaannssiioonn are enabled. + eexxttqquuoottee + If set, $$'_s_t_r_i_n_g' and $$"_s_t_r_i_n_g" quoting is performed + within $${{_p_a_r_a_m_e_t_e_r}} expansions enclosed in double + quotes. This option is enabled by default. + ffaaiillgglloobb + If set, patterns which fail to match filenames during + pathname expansion result in an expansion error. + ffoorrccee__ffiiggnnoorree + If set, the suffixes specified by the FFIIGGNNOORREE shell + variable cause words to be ignored when performing word + completion even if the ignored words are the only possi- + ble completions. See SSHHEELLLL VVAARRIIAABBLLEESS above for a + description of FFIIGGNNOORREE. This option is enabled by + default. + gglloobbssttaarr + If set, the pattern **** used in a pathname expansion con- + text will match a files and zero or more directories and + subdirectories. If the pattern is followed by a //, only + directories and subdirectories match. + ggnnuu__eerrrrffmmtt + If set, shell error messages are written in the standard + GNU error message format. + hhiissttaappppeenndd + If set, the history list is appended to the file named + by the value of the HHIISSTTFFIILLEE variable when the shell + exits, rather than overwriting the file. + hhiissttrreeeeddiitt + If set, and rreeaaddlliinnee is being used, a user is given the + opportunity to re-edit a failed history substitution. + hhiissttvveerriiffyy + If set, and rreeaaddlliinnee is being used, the results of his- + tory substitution are not immediately passed to the + shell parser. Instead, the resulting line is loaded + into the rreeaaddlliinnee editing buffer, allowing further modi- + fication. + hhoossttccoommpplleettee + If set, and rreeaaddlliinnee is being used, bbaasshh will attempt to + perform hostname completion when a word containing a @@ + is being completed (see CCoommpplleettiinngg under RREEAADDLLIINNEE + above). This is enabled by default. + hhuuppoonneexxiitt + If set, bbaasshh will send SSIIGGHHUUPP to all jobs when an inter- + active login shell exits. + iinntteerraaccttiivvee__ccoommmmeennttss + If set, allow a word beginning with ## to cause that word + and all remaining characters on that line to be ignored + in an interactive shell (see CCOOMMMMEENNTTSS above). This + option is enabled by default. + lliitthhiisstt If set, and the ccmmddhhiisstt option is enabled, multi-line + commands are saved to the history with embedded newlines + rather than using semicolon separators where possible. + llooggiinn__sshheellll + The shell sets this option if it is started as a login + shell (see IINNVVOOCCAATTIIOONN above). The value may not be + changed. + mmaaiillwwaarrnn + If set, and a file that bbaasshh is checking for mail has + been accessed since the last time it was checked, the + message ``The mail in _m_a_i_l_f_i_l_e has been read'' is dis- + played. + nnoo__eemmppttyy__ccmmdd__ccoommpplleettiioonn + If set, and rreeaaddlliinnee is being used, bbaasshh will not + attempt to search the PPAATTHH for possible completions when + completion is attempted on an empty line. + nnooccaasseegglloobb + If set, bbaasshh matches filenames in a case-insensitive + fashion when performing pathname expansion (see PPaatthhnnaammee + EExxppaannssiioonn above). + nnooccaasseemmaattcchh + If set, bbaasshh matches patterns in a case-insensitive + fashion when performing matching while executing ccaassee or + [[[[ conditional commands. + nnuullllgglloobb + If set, bbaasshh allows patterns which match no files (see + PPaatthhnnaammee EExxppaannssiioonn above) to expand to a null string, + rather than themselves. + pprrooggccoommpp + If set, the programmable completion facilities (see PPrroo-- + ggrraammmmaabbllee CCoommpplleettiioonn above) are enabled. This option is + enabled by default. + pprroommppttvvaarrss + If set, prompt strings undergo parameter expansion, com- + mand substitution, arithmetic expansion, and quote + removal 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 + restricted 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 + 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 + argument. This option is enabled by default. + xxppgg__eecchhoo + If set, the eecchhoo builtin expands backslash-escape + sequences by default. + ssuussppeenndd [--ff] + 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- + plied, or if job control is not enabled. + tteesstt _e_x_p_r + [[ _e_x_p_r ]] + Return a status of 0 or 1 depending on the evaluation of the + conditional expression _e_x_p_r. Each operator and operand 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 + depends on the number of arguments; see below. + !! _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 + 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. + _e_x_p_r_1 -oo _e_x_p_r_2 + True if either _e_x_p_r_1 or _e_x_p_r_2 is true. + + tteesstt and [[ evaluate conditional expressions using a set of rules + based on the number of arguments. + + 0 arguments + The expression is false. + 1 argument + The expression is true if and only if the argument is not + 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 + true if the unary test is true. If the first argument is + not a valid unary conditional operator, the expression is + false. + 3 arguments + 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 + 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- + wise, the expression is false. + 4 arguments + If the first argument is !!, the result is the negation of + the three-argument expression composed of the remaining + arguments. Otherwise, the expression is parsed and eval- + uated according to precedence using the rules listed + above. + 5 or more arguments + The expression is parsed and evaluated according to + precedence using the rules listed above. + + 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 + receives signal(s) _s_i_g_s_p_e_c. If _a_r_g is absent (and there is a + single _s_i_g_s_p_e_c) or --, each specified signal is reset to its + original disposition (the value it had upon entrance to the + shell). If _a_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 commands associated with each signal. The --ll option + causes the shell to print a list of signal names and their cor- + responding 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 SIG 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 + 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 sim- + ple command has a non-zero exit status, subject to 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, part of a + command executed in a &&&& or |||| list, or if the command's return + value is being inverted via !!. These are the same conditions + obeyed by the eerrrreexxiitt option. + + Signals ignored upon entry to the shell cannot be trapped or + reset. 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 + 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 + 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 + returned. 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 speci- + fied as a command name, or nothing if ``type -t name'' would not + return _f_i_l_e. The --PP option forces a PPAATTHH search for each _n_a_m_e, + even if ``type -t name'' would not return _f_i_l_e. If a command is + hashed, --pp and --PP print the hashed value, not necessarily 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 func- + tion lookup, as with the ccoommmmaanndd builtin. ttyyppee returns true if + all of the arguments are found, false if any are not found. + + uulliimmiitt [--HHSSTTaabbccddeeffiillmmnnppqqrrssttuuvvxx [_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. + 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- + 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, + respectively. 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 are printed before the value. Other options are inter- + preted as follows: + --aa All current limits are reported + --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 + children + --ii The maximum number of pending signals + --ll The maximum size that may be locked into memory + --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) + --pp The pipe size in 512-byte blocks (this may not be set) + --qq The maximum number of bytes in POSIX message queues + --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 + user + --vv The maximum amount of virtual memory available to the + shell + --xx The maximum number of file locks + --TT The maximum number of threads + + If _l_i_m_i_t is given, it is the new value of the specified resource + (the --aa option is display only). If no option is given, then --ff + is assumed. Values are in 1024-byte increments, except for --tt, + which is in seconds, --pp, which is in units of 512-byte blocks, + and --TT, --bb, --nn, and --uu, which are unscaled values. 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 + 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, + 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 + is true unless a supplied _n_a_m_e is not a defined alias. + + uunnsseett [-ffvv] [_n_a_m_e ...] + For each _n_a_m_e, remove the corresponding variable or function. + If no options are supplied, or the --vv option is given, each _n_a_m_e + refers to a shell variable. 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. Each unset vari- + able or function is removed from the environment passed to sub- + sequent commands. If any of CCOOMMPP__WWOORRDDBBRREEAAKKSS, RRAANNDDOOMM, SSEECCOONNDDSS, + LLIINNEENNOO, HHIISSTTCCMMDD, FFUUNNCCNNAAMMEE, GGRROOUUPPSS, or DDIIRRSSTTAACCKK are unset, they + lose their special properties, even if they are subsequently + reset. The exit status is true unless a _n_a_m_e is readonly. + + wwaaiitt [_n _._._.] + Wait for each specified process and return its termination sta- + tus. Each _n 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 _n is not given, all currently active child pro- + cesses are waited for, and the return status is zero. If _n + 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. + +SSEEEE AALLSSOO + bash(1), sh(1) + + + +GNU Bash-4.0 2004 Apr 20 BASH_BUILTINS(1) |