| 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) |