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BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) NNNNAAAAMMMMEEEE bash - GNU Bourne-Again SHell SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS bbbbaaaasssshhhh [options] [file] CCCCOOOOPPPPYYYYRRRRIIIIGGGGHHHHTTTT Bash is Copyright (C) 1989, 1991 by the Free Software Foundation, Inc. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN BBBBaaaasssshhhh is an sssshhhh-compatible command language interpreter that executes commands read from the standard input or from a file. BBBBaaaasssshhhh also incorporates useful features from the _K_o_r_n and _C shells (kkkksssshhhh and ccccsssshhhh). BBBBaaaasssshhhh is ultimately intended to be a conformant implementation of the IEEE Posix Shell and Tools specification (IEEE Working Group 1003.2). OOOOPPPPTTTTIIIIOOOONNNNSSSS In addition to the single-character shell options documented in the description of the sssseeeetttt builtin command, bbbbaaaasssshhhh interprets the following flags when it is invoked: ----cccc _s_t_r_i_n_g If the ----cccc flag is present, then commands are read from _s_t_r_i_n_g. If there are arguments after the _s_t_r_i_n_g, they are assigned to the positional parameters, starting with $$$$0000. ----iiii If the ----iiii flag is present, the shell is _i_n_t_e_r_a_c_t_i_v_e. ----ssss If the ----ssss flag is present, or if no arguments remain after option processing, then commands are read from the standard input. This option allows the positional parameters to be set when invoking an interactive shell. ---- A single ---- signals the end of options and disables further option processing. Any arguments after the ---- are treated as filenames and arguments. An argument of -------- is equivalent to an argument of ----. BBBBaaaasssshhhh also interprets a number of multi-character options. These options must appear on the command line before the single-character options to be recognized. ----nnnnoooorrrrcccc Do not read and execute the personal initialization file ~/._b_a_s_h_r_c if the shell is interactive. This option is on by default if the shell is invoked as sssshhhh. ----nnnnoooopppprrrrooooffffiiiilllleeee Do not read either the system-wide startup file /_e_t_c/_p_r_o_f_i_l_e or any of the personal initialization Page 1 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) files ~/._b_a_s_h__p_r_o_f_i_l_e, ~/._b_a_s_h__l_o_g_i_n, or ~/._p_r_o_f_i_l_e. By default, bbbbaaaasssshhhh normally reads these files when it is invoked as a login shell (see IIIINNNNVVVVOOOOCCCCAAAATTTTIIIIOOOONNNN below). ----rrrrccccffffiiiilllleeee _f_i_l_e Execute commands from _f_i_l_e instead of the standard personal initialization file ~/._b_a_s_h_r_c, if the shell is interactive (see IIIINNNNVVVVOOOOCCCCAAAATTTTIIIIOOOONNNN below). ----vvvveeeerrrrssssiiiioooonnnn Show the version number of this instance of bbbbaaaasssshhhh when starting. ----qqqquuuuiiiieeeetttt Do not be verbose when starting up (do not show the shell version or any other information). This is the default. ----llllooooggggiiiinnnn Make bbbbaaaasssshhhh act as if it had been invoked as a login shell. ----nnnnoooobbbbrrrraaaacccceeeeeeeexxxxppppaaaannnnssssiiiioooonnnn Do not perform curly brace expansion (see BBBBrrrraaaacccceeee EEEExxxxppppaaaannnnssssiiiioooonnnn below). ----nnnnoooolllliiiinnnneeeeeeeeddddiiiittttiiiinnnngggg Do not use the GNU _r_e_a_d_l_i_n_e library to read command lines if interactive. ----ppppoooossssiiiixxxx Change the behavior of bash where the default operation differs from the Posix 1003.2 standard to match the standard AAAARRRRGGGGUUUUMMMMEEEENNNNTTTTSSSS If arguments remain after option processing, and neither the ----cccc nor the ----ssss option has been supplied, the first argument is assumed to be the name of a file containing shell commands. If bbbbaaaasssshhhh is invoked in this fashion, $$$$0000 is set to the name of the file, and the positional parameters are set to the remaining arguments. BBBBaaaasssshhhh reads and executes commands from this file, then exits. BBBBaaaasssshhhh''''ssss exit status is the exit status of the last command executed in the script. DDDDEEEEFFFFIIIINNNNIIIITTTTIIIIOOOONNNNSSSS bbbbllllaaaannnnkkkk A space or tab. wwwwoooorrrrdddd A sequence of characters considered as a single unit by the shell. Also known as a ttttooookkkkeeeennnn. nnnnaaaammmmeeee A _w_o_r_d consisting only of alphanumeric characters and underscores, and beginning with an alphabetic character or an underscore. Also referred to as an iiiiddddeeeennnnttttiiiiffffiiiieeeerrrr. mmmmeeeettttaaaacccchhhhaaaarrrraaaacccctttteeeerrrr A character that, when unquoted, separates words. One of the following: |||| &&&& ;;;; (((( )))) <<<< >>>> ssssppppaaaacccceeee ttttaaaabbbb ccccoooonnnnttttrrrroooollll ooooppppeeeerrrraaaattttoooorrrr A _t_o_k_e_n that performs a control function. It is one of the following symbols: |||||||| &&&& &&&&&&&& ;;;; ;;;;;;;; (((( )))) |||| <<<<nnnneeeewwwwlllliiiinnnneeee>>>> Page 2 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) RRRREEEESSSSEEEERRRRVVVVEEEEDDDD WWWWOOOORRRRDDDDSSSS _R_e_s_e_r_v_e_d _w_o_r_d_s are words that have a special meaning to the shell. The following words are recognized as reserved when unquoted and either the first word of a simple command (see SSSSHHHHEEEELLLLLLLL GGGGRRRRAAAAMMMMMMMMAAAARRRR below) or the third word of a ccccaaaasssseeee or ffffoooorrrr command: !!!! ccccaaaasssseeee ddddoooo ddddoooonnnneeee eeeelllliiiiffff eeeellllsssseeee eeeessssaaaacccc ffffiiii ffffoooorrrr ffffuuuunnnnccccttttiiiioooonnnn iiiiffff iiiinnnn sssseeeelllleeeecccctttt tttthhhheeeennnn uuuunnnnttttiiiillll wwwwhhhhiiiilllleeee {{{{ }}}} SSSSHHHHEEEELLLLLLLL GGGGRRRRAAAAMMMMMMMMAAAARRRR SSSSiiiimmmmpppplllleeee CCCCoooommmmmmmmaaaannnnddddssss A _s_i_m_p_l_e _c_o_m_m_a_n_d is a sequence of optional variable assignments followed by _b_l_a_n_k-separated words and redirections, and terminated by a _c_o_n_t_r_o_l _o_p_e_r_a_t_o_r. The first word specifies the command to be executed. The remaining words are passed as arguments to the invoked command. The return value of a _s_i_m_p_l_e _c_o_m_m_a_n_d is its exit status, or 128+_n if the command is terminated by signal _n. PPPPiiiippppeeeelllliiiinnnneeeessss A _p_i_p_e_l_i_n_e is a sequence of one or more commands separated by the character ||||. The format for a pipeline is: [ ! ] _c_o_m_m_a_n_d [ |||| _c_o_m_m_a_n_d_2 ... ] The standard output of _c_o_m_m_a_n_d is connected to the standard input of _c_o_m_m_a_n_d_2. This connection is performed before any redirections specified by the command (see RRRREEEEDDDDIIIIRRRREEEECCCCTTTTIIIIOOOONNNN below). If the reserved word !!!! precedes a pipeline, the exit status of that pipeline is the logical NOT of the exit status of the last command. Otherwise, the status of the pipeline is the exit status of the last command. The shell waits for all commands in the pipeline to terminate before returning a value. Each command in a pipeline is executed as a separate process (i.e., in a subshell). LLLLiiiissssttttssss A _l_i_s_t is a sequence of one or more pipelines separated by one of the operators ;;;;, &&&&, &&&&&&&&, or ||||||||, and terminated by one of ;;;;, &&&&, or <<<<nnnneeeewwwwlllliiiinnnneeee>>>>. Of these list operators, &&&&&&&& and |||||||| have equal precedence, followed by ;;;; and &&&&,,,, which have equal precedence. If a command is terminated by the control operator &&&&, the Page 3 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) shell executes the command in the _b_a_c_k_g_r_o_u_n_d in a subshell. The shell does not wait for the command to finish, and the return status is 0. Commands separated by a ;;;; are executed sequentially; the shell waits for each command to terminate in turn. The return status is the exit status of the last command executed. The control operators &&&&&&&& and |||||||| denote AND lists and OR lists, respectively. An AND list has the form _c_o_m_m_a_n_d &&&&&&&& _c_o_m_m_a_n_d_2 _c_o_m_m_a_n_d_2 is executed if, and only if, _c_o_m_m_a_n_d returns an exit status of zero. An OR list has the form _c_o_m_m_a_n_d |||||||| _c_o_m_m_a_n_d_2 _c_o_m_m_a_n_d_2 is executed if and only if _c_o_m_m_a_n_d returns a non-zero exit status. The return status of AND and OR lists is the exit status of the last command executed in the list. CCCCoooommmmppppoooouuuunnnndddd CCCCoooommmmmmmmaaaannnnddddssss A _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d is one of the following: (_l_i_s_t) _l_i_s_t is executed in a subshell. Variable assignments and builtin commands that affect the shell's environment do not remain in effect after the command completes. The return status is the exit status of _l_i_s_t. { _l_i_s_t; } _l_i_s_t is simply executed in the current shell environment. This is known as a _g_r_o_u_p _c_o_m_m_a_n_d. The return status is the exit status of _l_i_s_t. ffffoooorrrr _n_a_m_e [ iiiinnnn _w_o_r_d; ] ddddoooo _l_i_s_t ; ddddoooonnnneeee The list of words following iiiinnnn is expanded, generating a list of items. The variable _n_a_m_e is set to each element of this list in turn, and _l_i_s_t is executed each time. If the iiiinnnn _w_o_r_d is omitted, the ffffoooorrrr command executes _l_i_s_t once for each positional parameter that is set (see PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS below). sssseeeelllleeeecccctttt _n_a_m_e [ iiiinnnn _w_o_r_d; ] ddddoooo _l_i_s_t ; ddddoooonnnneeee The list of words following iiiinnnn is expanded, generating a list of items. The set of expanded words is printed on the standard error, each preceded by a number. If the iiiinnnn _w_o_r_d is omitted, the positional parameters are printed (see PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS below). The PPPPSSSS3333 prompt is then Page 4 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) displayed and a line read from the standard input. If the line consists of the number corresponding to one of the displayed words, then the value of _n_a_m_e is set to that word. If the line is empty, the words and prompt are displayed again. If EOF is read, the command completes. Any other value read causes _n_a_m_e to be set to null. The line read is saved in the variable RRRREEEEPPPPLLLLYYYY. The _l_i_s_t is executed after each selection until a bbbbrrrreeeeaaaakkkk or rrrreeeettttuuuurrrrnnnn command is executed. The exit status of sssseeeelllleeeecccctttt is the exit status of the last command executed in _l_i_s_t, or zero if no commands were executed. ccccaaaasssseeee _w_o_r_d iiiinnnn [ _p_a_t_t_e_r_n [ |||| _p_a_t_t_e_r_n ] ... ) _l_i_s_t ;; ] ... eeeessssaaaacccc A ccccaaaasssseeee command first expands _w_o_r_d, and tries to match it against each _p_a_t_t_e_r_n in turn, using the same matching rules as for pathname expansion (see PPPPaaaatttthhhhnnnnaaaammmmeeee EEEExxxxppppaaaannnnssssiiiioooonnnn below). When a match is found, the corresponding _l_i_s_t is executed. After the first match, no subsequent matches are attempted. The exit status is zero if no patterns are matches. Otherwise, it is the exit status of the last command executed in _l_i_s_t. iiiiffff _l_i_s_t tttthhhheeeennnn _l_i_s_t [ eeeelllliiiiffff _l_i_s_t tttthhhheeeennnn _l_i_s_t ] ... [ eeeellllsssseeee _l_i_s_t ] ffffiiii The iiiiffff _l_i_s_t is executed. If its exit status is zero, the tttthhhheeeennnn _l_i_s_t is executed. Otherwise, each eeeelllliiiiffff _l_i_s_t is executed in turn, and if its exit status is zero, the corresponding tttthhhheeeennnn _l_i_s_t is executed and the command completes. Otherwise, the eeeellllsssseeee _l_i_s_t is executed, if present. The exit status is the exit status of the last command executed, or zero if no condition tested true. wwwwhhhhiiiilllleeee _l_i_s_t ddddoooo _l_i_s_t ddddoooonnnneeee uuuunnnnttttiiiillll _l_i_s_t ddddoooo _l_i_s_t ddddoooonnnneeee The wwwwhhhhiiiilllleeee command continuously executes the ddddoooo _l_i_s_t as long as the last command in _l_i_s_t returns an exit status of zero. The uuuunnnnttttiiiillll command is identical to the wwwwhhhhiiiilllleeee command, except that the test is negated; the ddddoooo _l_i_s_t is executed as long as the last command in _l_i_s_t returns a non-zero exit status. The exit status of the wwwwhhhhiiiilllleeee and uuuunnnnttttiiiillll commands is the exit status of the last ddddoooo _l_i_s_t command executed, or zero if none was executed. [ ffffuuuunnnnccccttttiiiioooonnnn ] _n_a_m_e () { _l_i_s_t; } This defines a function named _n_a_m_e. The _b_o_d_y of the function is the _l_i_s_t of commands between { and }. This list is executed whenever _n_a_m_e is specified as the name of a simple command. The exit status of a function is the exit status of the last command executed in the body. (See FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNNSSSS below.) CCCCOOOOMMMMMMMMEEEENNNNTTTTSSSS PPPPaaaaggggeeee 5555 ((((pppprrrriiiinnnntttteeeedddd 7777////6666////99995555)))) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) In a non-interactive shell, or an interactive shell in which the ----oooo iiiinnnntttteeeerrrraaaaccccttttiiiivvvveeee----ccccoooommmmmmmmeeeennnnttttssss option to the sssseeeetttt builtin is enabled, a word beginning with #### causes that word and all remaining characters on that line to be ignored. An interactive shell without the ----oooo iiiinnnntttteeeerrrraaaaccccttttiiiivvvveeee----ccccoooommmmmmmmeeeennnnttttssss option enabled does not allow comments. QQQQUUUUOOOOTTTTIIIINNNNGGGG _Q_u_o_t_i_n_g is used to remove the special meaning of certain characters or words to the shell. Quoting can be used to disable special treatment for special characters, to prevent reserved words from being recognized as such, and to prevent parameter expansion. Each of the _m_e_t_a_c_h_a_r_a_c_t_e_r_s listed above under DDDDEEEEFFFFIIIINNNNIIIITTTTIIIIOOOONNNNSSSS has special meaning to the shell and must be quoted if they are to represent themselves. There are three quoting mechanisms: the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r, single quotes, and double quotes. A non-quoted backslash (\\\\) is the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r. It preserves the literal value of the next character that follows, with the exception of <newline>. If a \\\\<newline> pair appears, and the backslash is not quoted, the \\\\<newline> is treated as a line continuation (that is, it is effectively ignored). Enclosing characters in single quotes preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a backslash. Enclosing characters in double quotes preserves the literal value of all characters within the quotes, with the exception of $$$$, ````, and \\\\. The characters $$$$ and ```` retain their special meaning within double quotes. The backslash retains its special meaning only when followed by one of the following characters: $$$$, ````, """", \\\\, or <<<<nnnneeeewwwwlllliiiinnnneeee>>>>. A double quote may be quoted within double quotes by preceding it with a backslash. The special parameters **** and @@@@ have special meaning when in double quotes (see PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS below). PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS A _p_a_r_a_m_e_t_e_r is an entity that stores values, somewhat like a variable in a conventional programming language. It can be a _n_a_m_e, a number, or one of the special characters listed below under SSSSppppeeeecccciiiiaaaallll PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss. For the shell's purposes, a _v_a_r_i_a_b_l_e is a parameter denoted by a _n_a_m_e. A parameter is set if it has been assigned a value. The Page 6 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) null string is a valid value. Once a variable is set, it may be unset only by using the uuuunnnnsssseeeetttt builtin command (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). A _v_a_r_i_a_b_l_e may be assigned to by a statement of the form _n_a_m_e=[_v_a_l_u_e] If _v_a_l_u_e is not given, the variable is assigned the null string. All _v_a_l_u_e_s undergo tilde expansion, parameter and variable expansion, command substitution, arithmetic expansion, and quote removal. If the variable has its ----iiii attribute set (see ddddeeeeccccllllaaaarrrreeee below in SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS) then _v_a_l_u_e is subject to arithmetic expansion even if the $[...] syntax does not appear. Word splitting is not performed, with the exception of """"$$$$@@@@"""" as explained below under SSSSppppeeeecccciiiiaaaallll PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss. Pathname expansion is not performed. PPPPoooossssiiiittttiiiioooonnnnaaaallll PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss A _p_o_s_i_t_i_o_n_a_l _p_a_r_a_m_e_t_e_r is a parameter denoted by one or more digits, other than the single digit 0. Positional parameters are assigned from the shell's arguments when it is invoked, and may be reassigned using the sssseeeetttt builtin command. Positional parameters may not be assigned to with assignment statements. The positional parameters are temporarily replaced when a shell function is executed (see FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNNSSSS below). When a positional parameter consisting of more than a single digit is expanded, it must be enclosed in braces (see EEEEXXXXPPPPAAAANNNNSSSSIIIIOOOONNNN below). SSSSppppeeeecccciiiiaaaallll PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss The shell treats several parameters specially. These parameters may only be referenced; assignment to them is not allowed. **** Expands to the positional parameters, starting from one. When the expansion occurs within double quotes, it expands to a single word with the value of each parameter separated by the first character of the IIIIFFFFSSSS special variable. That is, ``$$$$****'' is equivalent to ``$$$$1111_c$$$$2222_c............'', where _c is the first character of the value of the IIIIFFFFSSSS variable. If IIIIFFFFSSSS is null or unset, the parameters are separated by spaces. @@@@ Expands to the positional parameters, starting from one. When the expansion occurs within double quotes, each parameter expands as a separate word. That is, `` $$$$@@@@'' is equivalent to ``$$$$1111'' ``$$$$2222'' ... When there are no positional parameters, ``$$$$@@@@'' and $$$$@@@@ expand to nothing (i.e., they are removed). #### Expands to the number of positional parameters in Page 7 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) decimal. ???? Expands to the status of the most recently executed foreground pipeline. ---- Expands to the current option flags as specified upon invocation, by the sssseeeetttt builtin command, or those set by the shell itself (such as the ----iiii flag). $$$$ Expands to the process ID of the shell. In a () subshell, it expands to the process ID of the current shell, not the subshell. !!!! Expands to the process ID of the most recently executed background (asynchronous) command. 0000 Expands to the name of the shell or shell script. This is set at shell initialization. If bbbbaaaasssshhhh is invoked with a file of commands, $$$$0000 is set to the name of that file. If bbbbaaaasssshhhh is started with the ----cccc option, then $$$$0000 is set to the first argument after the string to be executed, if one is present. Otherwise, it is set to the pathname used to invoke bbbbaaaasssshhhh, as given by argument zero. ____ Expands to the last argument to the previous command, after expansion. Also set to the full pathname of each command executed and placed in the environment exported to that command. SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss The following variables are set by the shell: PPPPPPPPIIIIDDDD The process ID of the shell's parent. PPPPWWWWDDDD The current working directory as set by the ccccdddd command. OOOOLLLLDDDDPPPPWWWWDDDD The previous working directory as set by the ccccdddd command. RRRREEEEPPPPLLLLYYYY Set to the line of input read by the rrrreeeeaaaadddd builtin command when no arguments are supplied. UUUUIIIIDDDD Expands to the user ID of the current user, initialized at shell startup. EEEEUUUUIIIIDDDD Expands to the effective user ID of the current user, initialized at shell startup. BBBBAAAASSSSHHHH Expands to the full pathname used to invoke this instance of bbbbaaaasssshhhh. BBBBAAAASSSSHHHH____VVVVEEEERRRRSSSSIIIIOOOONNNN Expands to the version number of this instance of bbbbaaaasssshhhh. SSSSHHHHLLLLVVVVLLLL Incremented by one each time an instance of bbbbaaaasssshhhh is started. RRRRAAAANNNNDDDDOOOOMMMM Each time this parameter is referenced, a random integer is generated. The sequence of random numbers may be initialized by assigning a value to RRRRAAAANNNNDDDDOOOOMMMM. If RRRRAAAANNNNDDDDOOOOMMMM is unset, it loses its special properties, even if it is subsequently reset. Page 8 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) SSSSEEEECCCCOOOONNNNDDDDSSSS Each time this parameter is referenced, the number of seconds since shell invocation is returned. If a value is assigned to SSSSEEEECCCCOOOONNNNDDDDSSSS, the value returned upon subsequent references is the number of seconds since the assignment plus the value assigned. If SSSSEEEECCCCOOOONNNNDDDDSSSS is unset, it loses its special properties, even if it is subsequently reset. LLLLIIIINNNNEEEENNNNOOOO Each time this parameter is referenced, the shell substitutes a decimal number representing the current sequential line number (starting with 1) within a script or function. When not in a script or function, the value substituted is not guaranteed to be meaningful. When in a function, the value is not the number of the source line that the command appears on (that information has been lost by the time the function is executed), but is an approximation of the number of _s_i_m_p_l_e _c_o_m_m_a_n_d_s executed in the current function. If LLLLIIIINNNNEEEENNNNOOOO is unset, it loses its special properties, even if it is subsequently reset. HHHHIIIISSSSTTTTCCCCMMMMDDDD The history number, or index in the history list, of the current command. If HHHHIIIISSSSTTTTCCCCMMMMDDDD is unset, it loses its special properties, even if it is subsequently reset. OOOOPPPPTTTTAAAARRRRGGGG The value of the last option argument processed by the ggggeeeettttooooppppttttssss builtin command (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). OOOOPPPPTTTTIIIINNNNDDDD The index of the next argument to be processed by the ggggeeeettttooooppppttttssss builtin command (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). HHHHOOOOSSSSTTTTTTTTYYYYPPPPEEEE Automatically set to a string that uniquely describes the type of machine on which bbbbaaaasssshhhh is executing. The default is system-dependent. OOOOSSSSTTTTYYYYPPPPEEEE Automatically set to a string that describes the operating system on which bbbbaaaasssshhhh is executing. The default is system-dependent. The following variables are used by the shell. In some cases, bbbbaaaasssshhhh assigns a default value to a variable; these cases are noted below. IIIIFFFFSSSS The _I_n_t_e_r_n_a_l _F_i_e_l_d _S_e_p_a_r_a_t_o_r that is used for word splitting after expansion and to split lines into words with the rrrreeeeaaaadddd builtin command. The default value is ``<space><tab><newline>''. PPPPAAAATTTTHHHH The search path for commands. It is a colon-separated list of directories in which the shell looks for Page 9 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) commands (see CCCCOOOOMMMMMMMMAAAANNNNDDDD EEEEXXXXEEEECCCCUUUUTTTTIIIIOOOONNNN below). The default path is system-dependent, and is set by the administrator who installs bbbbaaaasssshhhh. A common value is ``/usr/gnu/bin:/usr/local/bin:/usr/ucb:/bin:/usr/bin:.''. HHHHOOOOMMMMEEEE The home directory of the current user; the default argument for the ccccdddd builtin command. CCCCDDDDPPPPAAAATTTTHHHH The search path for the ccccdddd command. This is a colon- separated list of directories in which the shell looks for destination directories specified by the ccccdddd command. A sample value is ``.:~:/usr''. EEEENNNNVVVV If this parameter is set when bbbbaaaasssshhhh is executing a shell script, its value is interpreted as a filename containing commands to initialize the shell, as in ._b_a_s_h_r_c. The value of EEEENNNNVVVV is subjected to parameter expansion, command substitution, and arithmetic expansion before being interpreted as a pathname. PPPPAAAATTTTHHHH is not used to search for the resultant pathname. MMMMAAAAIIIILLLL If this parameter is set to a filename and the MMMMAAAAIIIILLLLPPPPAAAATTTTHHHH variable is not set, bbbbaaaasssshhhh informs the user of the arrival of mail in the specified file. MMMMAAAAIIIILLLLCCCCHHHHEEEECCCCKKKK Specifies how often (in seconds) bbbbaaaasssshhhh checks for mail. The default is 60 seconds. When it is time to check for mail, the shell does so before prompting. If this variable is unset, the shell disables mail checking. MMMMAAAAIIIILLLLPPPPAAAATTTTHHHH A colon-separated list of pathnames to be checked for mail. The message to be printed may be specified by separating the pathname from the message with a `?'. $_ stands for the name of the current mailfile. Example: MMMMAAAAIIIILLLLPPPPAAAATTTTHHHH='/usr/spool/mail/bfox?"You have mail":~/shell-mail?"$_ has mail!"' BBBBaaaasssshhhh supplies a default value for this variable, but the location of the user mail files that it uses is system dependent (e.g., /usr/spool/mail/$$$$UUUUSSSSEEEERRRR). MMMMAAAAIIIILLLL____WWWWAAAARRRRNNNNIIIINNNNGGGG If set, and a file that bbbbaaaasssshhhh is checking for mail has been accessed since the last time it was checked, the message ``The mail in _m_a_i_l_f_i_l_e has been read'' is printed. PPPPSSSS1111 The value of this parameter is expanded (see PPPPRRRROOOOMMMMPPPPTTTTIIIINNNNGGGG below) and used as the primary prompt string. The default value is ``bbbbaaaasssshhhh\\\\$$$$ ''. PPPPSSSS2222 The value of this parameter is expanded and used as the secondary prompt string. The default is ``>>>> ''. PPPPSSSS3333 The value of this parameter is used as the prompt for the _s_e_l_e_c_t command (see SSSSHHHHEEEELLLLLLLL GGGGRRRRAAAAMMMMMMMMAAAARRRR above). PPPPSSSS4444 The value of this parameter is expanded and the value is printed before each command bbbbaaaasssshhhh displays during an execution trace. The first character of PPPPSSSS4444 is Page 10 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) replicated multiple times, as necessary, to indicate multiple levels of indirection. The default is ``++++ ''. HHHHIIIISSSSTTTTSSSSIIIIZZZZEEEE The number of commands to remember in the command history (see HHHHIIIISSSSTTTTOOOORRRRYYYY below). The default value is 500. HHHHIIIISSSSTTTTFFFFIIIILLLLEEEE The name of the file in which command history is saved. (See HHHHIIIISSSSTTTTOOOORRRRYYYY below.) The default value is ~/._b_a_s_h__h_i_s_t_o_r_y. If unset, the command history is not saved when an interactive shell exits. HHHHIIIISSSSTTTTFFFFIIIILLLLEEEESSSSIIIIZZZZEEEE The maximum number of lines contained in the history file. When this variable is assigned a value, the history file is truncated, if necessary, to contain no more than that number of lines. The default value is 500. OOOOPPPPTTTTEEEERRRRRRRR If set to the value 1, bbbbaaaasssshhhh displays error messages generated by the ggggeeeettttooooppppttttssss builtin command (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). OOOOPPPPTTTTEEEERRRRRRRR is initialized to 1 each time the shell is invoked or a shell script is executed. PPPPRRRROOOOMMMMPPPPTTTT____CCCCOOOOMMMMMMMMAAAANNNNDDDD If set, the value is executed as a command prior to issuing each primary prompt. IIIIGGGGNNNNOOOORRRREEEEEEEEOOOOFFFF Controls the action of the shell on receipt of an EEEEOOOOFFFF character as the sole input. If set, the value is the number of consecutive EEEEOOOOFFFF characters typed as the first characters on an input line before bbbbaaaasssshhhh exits. If the variable exists but does not have a numeric value, or has no value, the default value is 10. If it does not exist, EEEEOOOOFFFF signifies the end of input to the shell. This is only in effect for interactive shells. TTTTMMMMOOOOUUUUTTTT If set to a value greater than zero, the value is interpreted as the number of seconds to wait for input after issuing the primary prompt. BBBBaaaasssshhhh terminates after waiting for that number of seconds if input does not arrive. FFFFCCCCEEEEDDDDIIIITTTT The default editor for the ffffcccc builtin command. FFFFIIIIGGGGNNNNOOOORRRREEEE A colon-separated list of suffixes to ignore when performing filename completion (see RRRREEEEAAAADDDDLLLLIIIINNNNEEEE below). A filename whose suffix matches one of the entries in FFFFIIIIGGGGNNNNOOOORRRREEEE is excluded from the list of matched filenames. A sample value is ``.o:~''. IIIINNNNPPPPUUUUTTTTRRRRCCCC The filename for the readline startup file, overriding the default of ~/._i_n_p_u_t_r_c (see RRRREEEEAAAADDDDLLLLIIIINNNNEEEE below). nnnnoooottttiiiiffffyyyy Page 11 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) If set, bbbbaaaasssshhhh reports terminated background jobs immediately, rather than waiting until before printing the next primary prompt (see also the ----bbbb option to the sssseeeetttt builtin command). hhhhiiiissssttttoooorrrryyyy____ccccoooonnnnttttrrrroooollll HHHHIIIISSSSTTTTCCCCOOOONNNNTTTTRRRROOOOLLLL If set to a value of _i_g_n_o_r_e_s_p_a_c_e, lines which begin with a ssssppppaaaacccceeee character are not entered on the history list. If set to a value of _i_g_n_o_r_e_d_u_p_s, lines matching the last history line are not entered. A value of _i_g_n_o_r_e_b_o_t_h combines the two options. If unset, or if set to any other value than those above, all lines read by the parser are saved on the history list. ccccoooommmmmmmmaaaannnndddd____oooorrrriiiieeeennnntttteeeedddd____hhhhiiiissssttttoooorrrryyyy If set, bbbbaaaasssshhhh attempts to save all lines of a multiple-line command in the same history entry. This allows easy re-editing of multi-line commands. gggglllloooobbbb____ddddooootttt____ffffiiiilllleeeennnnaaaammmmeeeessss If set, bbbbaaaasssshhhh includes filenames beginning with a `.' in the results of pathname expansion. aaaalllllllloooowwww____nnnnuuuullllllll____gggglllloooobbbb____eeeexxxxppppaaaannnnssssiiiioooonnnn If set, bbbbaaaasssshhhh allows pathname patterns which match no files (see PPPPaaaatttthhhhnnnnaaaammmmeeee EEEExxxxppppaaaannnnssssiiiioooonnnn below) to expand to a null string, rather than themselves. hhhhiiiissssttttcccchhhhaaaarrrrssss The two or three characters which control history expansion and tokenization (see HHHHIIIISSSSTTTTOOOORRRRYYYY EEEEXXXXPPPPAAAANNNNSSSSIIIIOOOONNNN below). The first character is the _h_i_s_t_o_r_y _e_x_p_a_n_s_i_o_n _c_h_a_r_a_c_t_e_r, that is, the character which signals the start of a history expansion, normally `!!!!'. The second character is the _q_u_i_c_k _s_u_b_s_t_i_t_u_t_i_o_n character, which is used as shorthand for re-running the previous command entered, substituting one string for another in the command. The default is `^^^^'. The optional third character is the character which signifies that the remainder of the line is a comment, when found as the first character of a word, normally `####'. The history comment character causes history substitution to be skipped for the remaining words on the line. It does not necessarily cause the shell parser to treat the rest of the line as a comment. nnnnoooolllliiiinnnnkkkkssss If set, the shell does not follow symbolic links when executing commands that change the current working directory. It uses the physical directory structure instead. By default, bbbbaaaasssshhhh follows the logical chain of directories when performing commands which change the Page 12 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) current directory, such as ccccdddd. See also the description of the ----PPPP option to the sssseeeetttt builtin ( SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). hhhhoooossssttttnnnnaaaammmmeeee____ccccoooommmmpppplllleeeettttiiiioooonnnn____ffffiiiilllleeee HHHHOOOOSSSSTTTTFFFFIIIILLLLEEEE Contains the name of a file in the same format as /_e_t_c/_h_o_s_t_s that should be read when the shell needs to complete a hostname. The file may be changed interactively; the next time hostname completion is attempted bbbbaaaasssshhhh adds the contents of the new file to the already existing database. nnnnoooocccclllloooobbbbbbbbeeeerrrr If set, bbbbaaaasssshhhh does not overwrite an existing file with the >>>>, >>>>&&&&, and <<<<>>>> redirection operators. This variable may be overridden when creating output files by using the redirection operator >>>>|||| instead of >>>> (see also the ----CCCC option to the sssseeeetttt builtin command). aaaauuuuttttoooo____rrrreeeessssuuuummmmeeee This variable controls how the shell interacts with the user and job control. If this variable is set, single word simple commands without redirections are treated as candidates for resumption of an existing stopped job. There is no ambiguity allowed; if there is more than one job beginning with the string typed, the job most recently accessed is selected. The _n_a_m_e of a stopped job, in this context, is the command line used to start it. If set to the value _e_x_a_c_t, the string supplied must match the name of a stopped job exactly; if set to _s_u_b_s_t_r_i_n_g, the string supplied needs to match a substring of the name of a stopped job. The _s_u_b_s_t_r_i_n_g value provides functionality analogous to the %%%%???? job id (see JJJJOOOOBBBB CCCCOOOONNNNTTTTRRRROOOOLLLL below). If set to any other value, the supplied string must be a prefix of a stopped job's name; this provides functionality analogous to the %%%% job id. nnnnoooo____eeeexxxxiiiitttt____oooonnnn____ffffaaaaiiiilllleeeedddd____eeeexxxxeeeecccc If this variable exists, a non-interactive shell will not exit if it cannot execute the file specified in the eeeexxxxeeeecccc builtin command. An interactive shell does not exit if eeeexxxxeeeecccc fails. ccccddddaaaabbbblllleeee____vvvvaaaarrrrssss If this is set, an argument to the ccccdddd builtin command that is not a directory is assumed to be the name of a variable whose value is the directory to change to. EEEEXXXXPPPPAAAANNNNSSSSIIIIOOOONNNN Expansion is performed on the command line after it has been split into words. There are seven kinds of expansion Page 13 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) performed: _b_r_a_c_e _e_x_p_a_n_s_i_o_n, _t_i_l_d_e _e_x_p_a_n_s_i_o_n, _p_a_r_a_m_e_t_e_r _a_n_d _v_a_r_i_a_b_l_e _e_x_p_a_n_s_i_o_n, _c_o_m_m_a_n_d _s_u_b_s_t_i_t_u_t_i_o_n, _a_r_i_t_h_m_e_t_i_c _e_x_p_a_n_s_i_o_n, _w_o_r_d _s_p_l_i_t_t_i_n_g, and _p_a_t_h_n_a_m_e _e_x_p_a_n_s_i_o_n. The order of expansions is: brace expansion, tilde expansion, parameter, variable, command, and arithmetic substitution (done in a left-to-right fashion), word splitting, and pathname expansion. On systems that can support it, there is an additional expansion available: _p_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n. Only brace expansion, word splitting, and pathname expansion can change the number of words of the expansion; other expansions expand a single word to a single word. The single exception to this is the expansion of ``$$$$@@@@'' as explained above (see PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS). BBBBrrrraaaacccceeee EEEExxxxppppaaaannnnssssiiiioooonnnn _B_r_a_c_e _e_x_p_a_n_s_i_o_n is a mechanism by which arbitrary strings may be generated. This mechanism is similar to _p_a_t_h_n_a_m_e _e_x_p_a_n_s_i_o_n, but the filenames generated need not exist. Patterns to be brace expanded take the form of an optional _p_r_e_a_m_b_l_e, followed by a series of comma-separated strings between a pair of braces, followed by an optional _p_o_s_t_a_m_b_l_e. The preamble is prepended to each string contained within the braces, and the postamble is then appended to each resulting string, expanding left to right. Brace expansions may be nested. The results of each expanded string are not sorted; left to right order is preserved. For example, a{{{{d,c,b}}}}e expands into `ade ace abe'. Brace expansion is performed before any other expansions, and any characters special to other expansions are preserved in the result. It is strictly textual. BBBBaaaasssshhhh does not apply any syntactic interpretation to the context of the expansion or the text between the braces. A correctly-formed brace expansion must contain unquoted opening and closing braces, and at least one unquoted comma. Any incorrectly formed brace expansion is left unchanged. This construct is typically used as shorthand when the common prefix of the strings to be generated is longer than in the above example: mkdir /usr/local/src/bash/{old,new,dist,bugs} or chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}} Page 14 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) Brace expansion introduces a slight incompatibility with traditional versions of sssshhhh, the Bourne shell. sssshhhh does not treat opening or closing braces specially when they appear as part of a word, and preserves them in the output. BBBBaaaasssshhhh removes braces from words as a consequence of brace expansion. For example, a word entered to sssshhhh as _f_i_l_e{_1,_2} appears identically in the output. The same word is output as _f_i_l_e_1 _f_i_l_e_2 after expansion by bbbbaaaasssshhhh. If strict compatibility with sssshhhh is desired, start bbbbaaaasssshhhh with the ----nnnnoooobbbbrrrraaaacccceeeeeeeexxxxppppaaaannnnssssiiiioooonnnn flag (see OOOOPPPPTTTTIIIIOOOONNNNSSSS above) or disable brace expansion with the ++++oooo bbbbrrrraaaacccceeeeeeeexxxxppppaaaannnndddd option to the sssseeeetttt command (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). TTTTiiiillllddddeeee EEEExxxxppppaaaannnnssssiiiioooonnnn If a word begins with a tilde character (`~~~~'), all of the characters preceding the first slash (or all characters, if there is no slash) are treated as a possible _l_o_g_i_n _n_a_m_e. If this _l_o_g_i_n _n_a_m_e is the null string, the tilde is replaced with the value of the parameter HHHHOOOOMMMMEEEE. If HHHHOOOOMMMMEEEE is unset, the home directory of the user executing the shell is substituted instead. If a `+' follows the tilde, the value of PPPPWWWWDDDD replaces the tilde and `+'. If a `-' follows, the value of OOOOLLLLDDDDPPPPWWWWDDDD is substituted. If the value following the tilde is a valid _l_o_g_i_n _n_a_m_e, the tilde and _l_o_g_i_n _n_a_m_e are replaced with the home directory associated with that name. If the name is invalid, or the tilde expansion fails, the word is unchanged. Each variable assignment is checked for unquoted instances of tildes following a :::: or ====. In these cases, tilde substitution is also performed. Consequently, one may use pathnames with tildes in assignments to PPPPAAAATTTTHHHH, MMMMAAAAIIIILLLLPPPPAAAATTTTHHHH, and CCCCDDDDPPPPAAAATTTTHHHH, and the shell assigns the expanded value. PPPPaaaarrrraaaammmmeeeetttteeeerrrr EEEExxxxppppaaaannnnssssiiiioooonnnn The `$$$$' character introduces parameter expansion, command substitution, or arithmetic expansion. The parameter name or symbol to be expanded may be enclosed in braces, which are optional but serve to protect the variable to be expanded from characters immediately following it which could be interpreted as part of the name. ${_p_a_r_a_m_e_t_e_r} The value of _p_a_r_a_m_e_t_e_r is substituted. The braces are required when _p_a_r_a_m_e_t_e_r is a positional parameter with more than one digit, or when _p_a_r_a_m_e_t_e_r is followed by a character which is not to be interpreted as part of its name. In each of the cases below, _w_o_r_d is subject to tilde Page 15 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) expansion, parameter expansion, command substitution, and arithmetic expansion. BBBBaaaasssshhhh tests for a parameter that is unset or null; omitting the colon results in a test only for a parameter that is unset. ${_p_a_r_a_m_e_t_e_r::::----_w_o_r_d} UUUUsssseeee DDDDeeeeffffaaaauuuulllltttt VVVVaaaalllluuuueeeessss. If _p_a_r_a_m_e_t_e_r is unset or null, the expansion of _w_o_r_d is substituted. Otherwise, the value of _p_a_r_a_m_e_t_e_r is substituted. ${_p_a_r_a_m_e_t_e_r::::====_w_o_r_d} AAAAssssssssiiiiggggnnnn DDDDeeeeffffaaaauuuulllltttt VVVVaaaalllluuuueeeessss. If _p_a_r_a_m_e_t_e_r is unset or null, the expansion of _w_o_r_d is assigned to _p_a_r_a_m_e_t_e_r. The value of _p_a_r_a_m_e_t_e_r is then substituted. Positional parameters and special parameters may not be assigned to in this way. ${_p_a_r_a_m_e_t_e_r::::????_w_o_r_d} DDDDiiiissssppppllllaaaayyyy EEEErrrrrrrroooorrrr iiiiffff NNNNuuuullllllll oooorrrr UUUUnnnnsssseeeetttt. If _p_a_r_a_m_e_t_e_r is null or unset, the expansion of _w_o_r_d (or a message to that effect if _w_o_r_d is not present) is written to the standard error and the shell, if it is not interactive, exits. Otherwise, the value of _p_a_r_a_m_e_t_e_r is substituted. ${_p_a_r_a_m_e_t_e_r::::++++_w_o_r_d} UUUUsssseeee AAAAlllltttteeeerrrrnnnnaaaatttteeee VVVVaaaalllluuuueeee. If _p_a_r_a_m_e_t_e_r is null or unset, nothing is substituted, otherwise the expansion of _w_o_r_d is substituted. ${####_p_a_r_a_m_e_t_e_r} The length in characters of the value of _p_a_r_a_m_e_t_e_r is substituted. If _p_a_r_a_m_e_t_e_r is **** or @@@@, the length substituted is the length of **** expanded within double quotes. ${_p_a_r_a_m_e_t_e_r####_w_o_r_d} ${_p_a_r_a_m_e_t_e_r########_w_o_r_d} The _w_o_r_d is expanded to produce a pattern just as in pathname expansion. If the pattern matches the beginning of the value of _p_a_r_a_m_e_t_e_r, then the expansion is the value of _p_a_r_a_m_e_t_e_r with the shortest matching pattern deleted (the ``####'' case) or the longest matching pattern deleted (the ``########'' case). ${_p_a_r_a_m_e_t_e_r%%%%_w_o_r_d} ${_p_a_r_a_m_e_t_e_r%%%%%%%%_w_o_r_d} The _w_o_r_d is expanded to produce a pattern just as in pathname expansion. If the pattern matches a trailing portion of the value of _p_a_r_a_m_e_t_e_r, then the expansion is the value of _p_a_r_a_m_e_t_e_r with the shortest matching pattern deleted (the ``%%%%'' case) or the longest matching pattern deleted (the ``%%%%%%%%'' case). CCCCoooommmmmmmmaaaannnndddd SSSSuuuubbbbssssttttiiiittttuuuuttttiiiioooonnnn _C_o_m_m_a_n_d _s_u_b_s_t_i_t_u_t_i_o_n allows the output of a command to replace the command name. There are two forms: Page 16 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) $$$$((((_c_o_m_m_a_n_d)))) or ````_c_o_m_m_a_n_d```` BBBBaaaasssshhhh performs the expansion by executing _c_o_m_m_a_n_d and replacing the command substitution with the standard output of the command, with any trailing newlines deleted. When the old-style backquote form of substitution is used, backslash retains its literal meaning except when followed by $$$$, ````, or \\\\. When using the $(_c_o_m_m_a_n_d) form, all characters between the parentheses make up the command; none are treated specially. Command substitutions may be nested. To nest when using the old form, escape the inner backquotes with backslashes. If the substitution appears within double quotes, word splitting and pathname expansion are not performed on the results. AAAArrrriiiitttthhhhmmmmeeeettttiiiicccc EEEExxxxppppaaaannnnssssiiiioooonnnn Arithmetic expansion allows the evaluation of an arithmetic expression and the substitution of the result. There are two formats for arithmetic expansion: $$$$[[[[_e_x_p_r_e_s_s_i_o_n]]]] $$$$((((((((_e_x_p_r_e_s_s_i_o_n)))))))) The _e_x_p_r_e_s_s_i_o_n is treated as if it were within double quotes, but a double quote inside the braces or parentheses is not treated specially. All tokens in the expression undergo parameter expansion, command substitution, and quote removal. Arithmetic substitutions may be nested. The evaluation is performed according to the rules listed below under AAAARRRRIIIITTTTHHHHMMMMEEEETTTTIIIICCCC EEEEVVVVAAAALLLLUUUUAAAATTTTIIIIOOOONNNN. If _e_x_p_r_e_s_s_i_o_n is invalid, bbbbaaaasssshhhh prints a message indicating failure and no substitution occurs. PPPPrrrroooocccceeeessssssss SSSSuuuubbbbssssttttiiiittttuuuuttttiiiioooonnnn _P_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n is supported on systems that support named pipes (_F_I_F_O_s) or the ////ddddeeeevvvv////ffffdddd method of naming open files. It takes the form of <<<<((((_l_i_s_t)))) or >>>>((((_l_i_s_t)))). The process _l_i_s_t is run with its input or output connected to a _F_I_F_O or some file in ////ddddeeeevvvv////ffffdddd. The name of this file is passed as an argument to the current command as the result of the expansion. If the >>>>((((_l_i_s_t)))) form is used, writing to the file will provide input for _l_i_s_t. If the <<<<((((_l_i_s_t)))) form is used, the file passed as an argument should be read to obtain the output of _l_i_s_t. Page 17 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) On systems that support it, _p_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n is performed simultaneously with _p_a_r_a_m_e_t_e_r _a_n_d _v_a_r_i_a_b_l_e _e_x_p_a_n_s_i_o_n, _c_o_m_m_a_n_d _s_u_b_s_t_i_t_u_t_i_o_n, and _a_r_i_t_h_m_e_t_i_c _e_x_p_a_n_s_i_o_n. WWWWoooorrrrdddd SSSSpppplllliiiittttttttiiiinnnngggg The shell scans the results of parameter expansion, command substitution, and arithmetic expansion that did not occur within double quotes for _w_o_r_d _s_p_l_i_t_t_i_n_g. The shell treats each character of IIIIFFFFSSSS as a delimiter, and splits the results of the other expansions into words on these characters. If the value of IIIIFFFFSSSS is exactly <<<<ssssppppaaaacccceeee>>>><<<<ttttaaaabbbb>>>><<<<nnnneeeewwwwlllliiiinnnneeee>>>>, the default, then any sequence of IIIIFFFFSSSS characters serves to delimit words. If IIIIFFFFSSSS has a value other than the default, then sequences of the whitespace characters ssssppppaaaacccceeee and ttttaaaabbbb are ignored at the beginning and end of the word, as long as the whitespace character is in the value of IIIIFFFFSSSS (an IIIIFFFFSSSS whitespace character). Any character in IIIIFFFFSSSS that is not IIIIFFFFSSSS whitespace, along with any adjacent IIIIFFFFSSSS whitespace characters, delimits a field. A sequence of IIIIFFFFSSSS whitespace characters is also treated as a delimiter. If the value of IIIIFFFFSSSS is null, no word splitting occurs. IIIIFFFFSSSS cannot be unset. Explicit null arguments ("""""""" or '''''''') are retained. Implicit null arguments, resulting from the expansion of _p_a_r_a_m_e_t_e_r_s that have no values, are removed. Note that if no expansion occurs, no splitting is performed. PPPPaaaatttthhhhnnnnaaaammmmeeee EEEExxxxppppaaaannnnssssiiiioooonnnn After word splitting, unless the ----ffff option has been set, bbbbaaaasssshhhh scans each _w_o_r_d for the characters ****, ????, and [[[[. If one of these characters appears, then the word is regarded as a _p_a_t_t_e_r_n, and replaced with an alphabetically sorted list of pathnames matching the pattern. If no matching pathnames are found, and the shell variable aaaalllllllloooowwww____nnnnuuuullllllll____gggglllloooobbbb____eeeexxxxppppaaaannnnssssiiiioooonnnn is unset, the word is left unchanged. If the variable is set, and no matches are found, the word is removed. When a pattern is used for pathname generation, the character ````````....'''''''' at the start of a name or immediately following a slash must be matched explicitly, unless the shell variable gggglllloooobbbb____ddddooootttt____ffffiiiilllleeeennnnaaaammmmeeeessss is set. The slash character must always be matched explicitly. In other cases, the ````````....'''''''' character is not treated specially. The special pattern characters have the following meanings: **** Matches any string, including the null string. ???? Matches any single character. [[[[............]]]] Matches any one of the enclosed characters. A pair of Page 18 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) characters separated by a minus sign denotes a _r_a_n_g_e; any character lexically between those two characters, inclusive, is matched. If the first character following the [[[[ is a !!!! or a ^^^^ then any character not enclosed is matched. A ---- or ]]]] may be matched by including it as the first or last character in the set. QQQQuuuuooootttteeee RRRReeeemmmmoooovvvvaaaallll After the preceding expansions, all unquoted occurrences of the characters \\\\, ````, and """" are removed. RRRREEEEDDDDIIIIRRRREEEECCCCTTTTIIIIOOOONNNN Before a command is executed, its input and output may be _r_e_d_i_r_e_c_t_e_d using a special notation interpreted by the shell. Redirection may also be used to open and close files for the current shell execution environment. The following redirection operators may precede or appear anywhere within a _s_i_m_p_l_e _c_o_m_m_a_n_d or may follow a _c_o_m_m_a_n_d. Redirections are processed in the order they appear, from left to right. In the following descriptions, if the file descriptor number is omitted, and the first character of the redirection operator is <<<<, the redirection refers to the standard input (file descriptor 0). If the first character of the redirection operator is >>>>, the redirection refers to the standard output (file descriptor 1). The word that follows the redirection operator in the following descriptions is subjected to brace expansion, tilde expansion, parameter expansion, command substitution, arithmetic expansion, quote removal, and pathname expansion. If it expands to more than one word, bbbbaaaasssshhhh reports an error. Note that the order of redirections is significant. For example, the command ls >>>> dirlist 2>>>>&&&&1 directs both standard output and standard error to the file _d_i_r_l_i_s_t, while the command ls 2>>>>&&&&1 >>>> dirlist directs only the standard output to file _d_i_r_l_i_s_t, because the standard error was duplicated as standard output before the standard output was redirected to _d_i_r_l_i_s_t. RRRReeeeddddiiiirrrreeeeccccttttiiiinnnngggg IIIInnnnppppuuuutttt Redirection of input causes the file whose name results from the expansion of _w_o_r_d to be opened for reading on file descriptor _n, or the standard input (file descriptor 0) if _n is not specified. Page 19 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) The general format for redirecting input is: [_n]<<<<_w_o_r_d RRRReeeeddddiiiirrrreeeeccccttttiiiinnnngggg OOOOuuuuttttppppuuuutttt Redirection of output causes the file whose name results from the expansion of _w_o_r_d to be opened for writing on file descriptor _n, or the standard output (file descriptor 1) if _n is not specified. If the file does not exist it is created; if it does exist it is truncated to zero size. The general format for redirecting output is: [_n]>>>>_w_o_r_d If the redirection operator is >>>>||||, then the value of the ----CCCC option to the sssseeeetttt builtin command is not tested, and file creation is attempted. (See also the description of nnnnoooocccclllloooobbbbbbbbeeeerrrr under SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss above.) AAAAppppppppeeeennnnddddiiiinnnngggg RRRReeeeddddiiiirrrreeeecccctttteeeedddd OOOOuuuuttttppppuuuutttt Redirection of output in this fashion causes the file whose name results from the expansion of _w_o_r_d to be opened for appending on file descriptor _n, or the standard output (file descriptor 1) if _n is not specified. If the file does not exist it is created. The general format for appending output is: [_n]>>>>>>>>_w_o_r_d RRRReeeeddddiiiirrrreeeeccccttttiiiinnnngggg SSSSttttaaaannnnddddaaaarrrrdddd OOOOuuuuttttppppuuuutttt aaaannnndddd SSSSttttaaaannnnddddaaaarrrrdddd EEEErrrrrrrroooorrrr BBBBaaaasssshhhh allows both the standard output (file descriptor 1) and the standard error output (file descriptor 2) to be redirected to the file whose name is the expansion of _w_o_r_d with this construct. There are two formats for redirecting standard output and standard error: &&&&>>>>_w_o_r_d and >>>>&&&&_w_o_r_d Of the two forms, the first is preferred. This is semantically equivalent to >>>>_w_o_r_d 2>>>>&&&&1 HHHHeeeerrrreeee DDDDooooccccuuuummmmeeeennnnttttssss This type of redirection instructs the shell to read input from the current source until a line containing only _w_o_r_d Page 20 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) (with no trailing blanks) is seen. All of the lines read up to that point are then used as the standard input for a command. The format of here-documents is as follows: <<<<<<<<[----]_w_o_r_d _h_e_r_e-_d_o_c_u_m_e_n_t _d_e_l_i_m_i_t_e_r No parameter expansion, command substitution, pathname expansion, or arithmetic expansion is performed on _w_o_r_d. If any characters in _w_o_r_d are quoted, the _d_e_l_i_m_i_t_e_r is the result of quote removal on _w_o_r_d, and the lines in the here- document are not expanded. Otherwise, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion. In the latter case, the pair \\\\<<<<nnnneeeewwwwlllliiiinnnneeee>>>> is ignored, and \\\\ must be used to quote the characters \\\\, $$$$, and ````. If the redirection operator is <<<<<<<<----, then all leading tab characters are stripped from input lines and the line containing _d_e_l_i_m_i_t_e_r. This allows here-documents within shell scripts to be indented in a natural fashion. DDDDuuuupppplllliiiiccccaaaattttiiiinnnngggg FFFFiiiilllleeee DDDDeeeessssccccrrrriiiippppttttoooorrrrssss The redirection operator [_n]<<<<&&&&_w_o_r_d is used to duplicate input file descriptors. If _w_o_r_d expands to one or more digits, the file descriptor denoted by _n is made to be a copy of that file descriptor. If _w_o_r_d evaluates to ----, file descriptor _n is closed. If _n is not specified, the standard input (file descriptor 0) is used. The operator [_n]>>>>&&&&_w_o_r_d is used similarly to duplicate output file descriptors. If _n is not specified, the standard output (file descriptor 1) is used. As a special case, if _n is omitted, and _w_o_r_d does not expand to one or more digits, the standard output and standard error are redirected as described previously. OOOOppppeeeennnniiiinnnngggg FFFFiiiilllleeee DDDDeeeessssccccrrrriiiippppttttoooorrrrssss ffffoooorrrr RRRReeeeaaaaddddiiiinnnngggg aaaannnndddd WWWWrrrriiiittttiiiinnnngggg The redirection operator [_n]<<<<>>>>_w_o_r_d causes the file whose name is the expansion of _w_o_r_d to be Page 21 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) opened for both reading and writing on file descriptor _n, or as the standard input and standard output if _n is not specified. If the file does not exist, it is created. FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNNSSSS A shell function, defined as described above under SSSSHHHHEEEELLLLLLLL GGGGRRRRAAAAMMMMMMMMAAAARRRR, stores a series of commands for later execution. Functions are executed in the context of the current shell; no new process is created to interpret them (contrast this with the execution of a shell script). When a function is executed, the arguments to the function become the positional parameters during its execution. The special parameter #### is updated to reflect the change. Positional parameter 0 is unchanged. Variables local to the function may be declared with the llllooooccccaaaallll builtin command. Ordinarily, variables and their values are shared between the function and its caller. If the builtin command rrrreeeettttuuuurrrrnnnn is executed in a function, the function completes and execution resumes with the next command after the function call. When a function completes, the values of the positional parameters and the special parameter #### are restored to the values they had prior to function execution. Function names may be listed with the ----ffff option to the ddddeeeeccccllllaaaarrrreeee or ttttyyyyppppeeeesssseeeetttt builtin commands. Functions may be exported so that subshells automatically have them defined with the ----ffff option to the eeeexxxxppppoooorrrrtttt builtin. Functions may be recursive. No limit is imposed on the number of recursive calls. AAAALLLLIIIIAAAASSSSEEEESSSS The shell maintains a list of _a_l_i_a_s_e_s that may be set and unset with the aaaalllliiiiaaaassss and uuuunnnnaaaalllliiiiaaaassss builtin commands (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). The first word of each command, if unquoted, is checked to see if it has an alias. If so, that word is replaced by the text of the alias. The alias name and the replacement text may contain any valid shell input, including the _m_e_t_a_c_h_a_r_a_c_t_e_r_s listed above, with the exception that the alias name may not contain =. The first word of the replacement text is tested for aliases, but a word that is identical to an alias being expanded is not expanded a second time. This means that one may alias llllssss to llllssss ----FFFF, for instance, and bbbbaaaasssshhhh does not try to recursively expand the replacement text. If the last character of the alias value is a _b_l_a_n_k, then the next command word following the alias is also checked for alias expansion. Aliases are created and listed with the aaaalllliiiiaaaassss command, and Page 22 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) removed with the uuuunnnnaaaalllliiiiaaaassss command. There is no mechanism for using arguments in the replacement text, as in ccccsssshhhh. If arguments are needed, a shell function should be used. Aliases are not expanded when the shell is not interactive. The rules concerning the definition and use of aliases are somewhat confusing. BBBBaaaasssshhhh always reads at least one complete line of input before executing any of the commands on that line. Aliases are expanded when a command is read, not when it is executed. Therefore, an alias definition appearing on the same line as another command does not take effect until the next line of input is read. This means that the commands following the alias definition on that line are not affected by the new alias. This behavior is also an issue when functions are executed. Aliases are expanded when the function definition is read, not when the function is executed, because a function definition is itself a compound command. As a consequence, aliases defined in a function are not available until after that function is executed. To be safe, always put alias definitions on a separate line, and do not use aaaalllliiiiaaaassss in compound commands. Note that for almost every purpose, aliases are superseded by shell functions. JJJJOOOOBBBB CCCCOOOONNNNTTTTRRRROOOOLLLL _J_o_b _c_o_n_t_r_o_l refers to the ability to selectively stop (_s_u_s_p_e_n_d) the execution of processes and continue (_r_e_s_u_m_e) their execution at a later point. A user typically employs this facility via an interactive interface supplied jointly by the system's terminal driver and bbbbaaaasssshhhh. The shell associates a _j_o_b with each pipeline. It keeps a table of currently executing jobs, which may be listed with the jjjjoooobbbbssss command. When bbbbaaaasssshhhh starts a job asynchronously (in the _b_a_c_k_g_r_o_u_n_d), it prints a line that looks like: [1] 25647 indicating that this job is job number 1 and that the process ID of the last process in the pipeline associated with this job is 25647. All of the processes in a single pipeline are members of the same job. BBBBaaaasssshhhh uses the _j_o_b abstraction as the basis for job control. To facilitate the implementation of the user interface to job control, the system maintains the notion of a _c_u_r_r_e_n_t _t_e_r_m_i_n_a_l _p_r_o_c_e_s_s _g_r_o_u_p _I_D. Members of this process group (processes whose process group ID is equal to the current Page 23 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) terminal process group ID) receive keyboard-generated signals such as SSSSIIIIGGGGIIIINNNNTTTT. These processes are said to be in the _f_o_r_e_g_r_o_u_n_d. _B_a_c_k_g_r_o_u_n_d processes are those whose process group ID differs from the terminal's; such processes are immune to keyboard-generated signals. Only foreground processes are allowed to read from or write to the terminal. Background processes which attempt to read from (write to) the terminal are sent a SSSSIIIIGGGGTTTTTTTTIIIINNNN ((((SSSSIIIIGGGGTTTTTTTTOOOOUUUU)))) signal by the terminal driver, which, unless caught, suspends the process. If the operating system on which bbbbaaaasssshhhh is running supports job control, bbbbaaaasssshhhh allows you to use it. Typing the _s_u_s_p_e_n_d character (typically ^^^^ZZZZ, Control-Z) while a process is running causes that process to be stopped and returns you to bbbbaaaasssshhhh. Typing the _d_e_l_a_y_e_d _s_u_s_p_e_n_d character (typically ^^^^YYYY, Control-Y) causes the process to be stopped when it attempts to read input from the terminal, and control to be returned to bbbbaaaasssshhhh. You may then manipulate the state of this job, using the bbbbgggg command to continue it in the background, the ffffgggg command to continue it in the foreground, or the kkkkiiiillllllll command to kill it. A ^^^^ZZZZ takes effect immediately, and has the additional side effect of causing pending output and typeahead to be discarded. There are a number of ways to refer to a job in the shell. The character %%%% introduces a job name. Job number _n may be referred to as %%%%nnnn. A job may also be referred to using a prefix of the name used to start it, or using a substring that appears in its command line. For example, %%%%cccceeee refers to a stopped cccceeee job. If a prefix matches more than one job, bbbbaaaasssshhhh reports an error. Using %%%%????cccceeee, on the other hand, refers to any job containing the string cccceeee in its command line. If the substring matches more than one job, bbbbaaaasssshhhh reports an error. The symbols %%%%%%%% and %%%%++++ refer to the shell's notion of the _c_u_r_r_e_n_t _j_o_b, which is the last job stopped while it was in the foreground. The _p_r_e_v_i_o_u_s _j_o_b may be referenced using %%%%----. In output pertaining to jobs (e.g., the output of the jjjjoooobbbbssss command), the current job is always flagged with a ++++, and the previous job with a ----. Simply naming a job can be used to bring it into the foreground: %%%%1111 is a synonym for ````````ffffgggg %%%%1111'''''''', bringing job 1 from the background into the foreground. Similarly, ````````%%%%1111 &&&&'''''''' resumes job 1 in the background, equivalent to ````````bbbbgggg %%%%1111''''''''. The shell learns immediately whenever a job changes state. Normally, bbbbaaaasssshhhh waits until it is about to print a prompt before reporting changes in a job's status so as to not interrupt any other output. If the ----bbbb option to the sssseeeetttt builtin command is set, bbbbaaaasssshhhh reports such changes immediately. (See also the description of nnnnoooottttiiiiffffyyyy variable Page 24 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) under SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss above.) If you attempt to exit bbbbaaaasssshhhh while jobs are stopped, the shell prints a message warning you. You may then use the jjjjoooobbbbssss command to inspect their status. If you do this, or try to exit again immediately, you are not warned again, and the stopped jobs are terminated. SSSSIIIIGGGGNNNNAAAALLLLSSSS When bbbbaaaasssshhhh is interactive, it ignores SSSSIIIIGGGGTTTTEEEERRRRMMMM (so that kkkkiiiillllllll 0000 does not kill an interactive shell), and SSSSIIIIGGGGIIIINNNNTTTT is caught and handled (so that the wwwwaaaaiiiitttt builtin is interruptible). In all cases, bbbbaaaasssshhhh ignores SSSSIIIIGGGGQQQQUUUUIIIITTTT. If job control is in effect, bbbbaaaasssshhhh ignores SSSSIIIIGGGGTTTTTTTTIIIINNNN, SSSSIIIIGGGGTTTTTTTTOOOOUUUU, and SSSSIIIIGGGGTTTTSSSSTTTTPPPP. Synchronous jobs started by bbbbaaaasssshhhh have signals set to the values inherited by the shell from its parent. When job control is not in effect, background jobs (jobs started with &&&&) ignore SSSSIIIIGGGGIIIINNNNTTTT and SSSSIIIIGGGGQQQQUUUUIIIITTTT. Commands run as a result of command substitution ignore the keyboard-generated job control signals SSSSIIIIGGGGTTTTTTTTIIIINNNN, SSSSIIIIGGGGTTTTTTTTOOOOUUUU, and SSSSIIIIGGGGTTTTSSSSTTTTPPPP. CCCCOOOOMMMMMMMMAAAANNNNDDDD EEEEXXXXEEEECCCCUUUUTTTTIIIIOOOONNNN After a command has been split into words, if it results in a simple command and an optional list of arguments, the following actions are taken. If the command name contains no slashes, the shell attempts to locate it. If there exists a shell function by that name, that function is invoked as described above in FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNNSSSS. If the name does not match a function, the shell searches for it in the list of shell builtins. If a match is found, that builtin is invoked. If the name is neither a shell function nor a builtin, and contains no slashes, bbbbaaaasssshhhh searches each element of the PPPPAAAATTTTHHHH for a directory containing an executable file by that name. If the search is unsuccessful, the shell prints an error message and returns a nonzero exit status. If the search is successful, or if the command name contains one or more slashes, the shell executes the named program. Argument 0 is set to the name given, and the remaining arguments to the command are set to the arguments given, if any. If this execution fails because the file is not in executable format, and the file is not a directory, it is assumed to be a _s_h_e_l_l _s_c_r_i_p_t, a file containing shell commands. A subshell is spawned to execute it. This subshell reinitializes itself, so that the effect is as if a new shell had been invoked to handle the script, with the Page 25 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) exception that the locations of commands remembered by the parent (see hhhhaaaasssshhhh below under SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS) are retained by the child. If the program is a file beginning with ####!!!!, the remainder of the first line specifies an interpreter for the program. The shell executes the specified interpreter on operating systems that do not handle this executable format themselves. The arguments to the interpreter consist of a single optional argument following the interpreter name on the first line of the program, followed by the name of the program, followed by the command arguments, if any. EEEENNNNVVVVIIIIRRRROOOONNNNMMMMEEEENNNNTTTT When a program is invoked it is given an array of strings called the _e_n_v_i_r_o_n_m_e_n_t. This is a list of _n_a_m_e-_v_a_l_u_e pairs, of the form _n_a_m_e=_v_a_l_u_e. The shell allows you to manipulate the environment in several ways. On invocation, the shell scans its own environment and creates a parameter for each name found, automatically marking it for _e_x_p_o_r_t to child processes. Executed commands inherit the environment. The eeeexxxxppppoooorrrrtttt and ddddeeeeccccllllaaaarrrreeee ----xxxx commands allow parameters and functions to be added to and deleted from the environment. If the value of a parameter in the environment is modified, the new value becomes part of the environment, replacing the old. The environment inherited by any executed command consists of the shell's initial environment, whose values may be modified in the shell, less any pairs removed by the uuuunnnnsssseeeetttt command, plus any additions via the eeeexxxxppppoooorrrrtttt and ddddeeeeccccllllaaaarrrreeee ----xxxx commands. The environment for any _s_i_m_p_l_e _c_o_m_m_a_n_d or function may be augmented temporarily by prefixing it with parameter assignments, as described above in PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS. These assignment statements affect only the environment seen by that command. If the ----kkkk flag is set (see the sssseeeetttt builtin command below), then _a_l_l parameter assignments are placed in the environment for a command, not just those that precede the command name. When bbbbaaaasssshhhh invokes an external command, the variable ____ is set to the full path name of the command and passed to that command in its environment. EEEEXXXXIIIITTTT SSSSTTTTAAAATTTTUUUUSSSS For the purposes of the shell, a command which exits with a zero exit status has succeeded. An exit status of zero indicates success. A non-zero exit status indicates failure. When a command terminates on a fatal signal, bbbbaaaasssshhhh Page 26 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) uses the value of 128+ssssiiiiggggnnnnaaaallll as the exit status. If a command is not found, the child process created to execute it returns a status of 127. If a command is found but is not executable, the return status is 126. BBBBaaaasssshhhh itself returns the exit status of the last command executed, unless a syntax error occurs, in which case it exits with a non-zero value. See also the eeeexxxxiiiitttt builtin command below. PPPPRRRROOOOMMMMPPPPTTTTIIIINNNNGGGG When executing interactively, bbbbaaaasssshhhh displays the primary prompt PPPPSSSS1111 when it is ready to read a command, and the secondary prompt PPPPSSSS2222 when it needs more input to complete a command. BBBBaaaasssshhhh allows these prompt strings to be customized by inserting a number of backslash-escaped special characters that are decoded as follows: \\\\tttt the current time in HH:MM:SS format \\\\dddd the date in "Weekday Month Date" format (e.g., "Tue May 26") \\\\nnnn newline \\\\ssss the name of the shell, the basename of $$$$0000 (the portion following the final slash) \\\\wwww the current working directory \\\\WWWW the basename of the current working directory \\\\uuuu the username of the current user \\\\hhhh the hostname \\\\#### the command number of this command \\\\!!!! the history number of this command \\\\$$$$ if the effective UID is 0, a ####, otherwise a $$$$ \\\\nnnnnnnnnnnn the character corresponding to the octal number nnnnnnnnnnnn \\\\\\\\ a backslash \\\\[[[[ begin a sequence of non-printing characters, which could be used to embed a terminal control sequence into the prompt \\\\]]]] end a sequence of non-printing characters The command number and the history number are usually different: the history number of a command is its position in the history list, which may include commands restored from the history file (see HHHHIIIISSSSTTTTOOOORRRRYYYY below), while the command number is the position in the sequence of commands executed during the current shell session. After the string is decoded, it is expanded via parameter expansion, command substitution, arithmetic expansion, and word splitting. RRRREEEEAAAADDDDLLLLIIIINNNNEEEE This is the library that handles reading input when using an interactive shell, unless the ----nnnnoooolllliiiinnnneeeeeeeeddddiiiittttiiiinnnngggg option is given. By default, the line editing commands are similar to Page 27 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) those of emacs. A vi-style line editing interface is also available. In this section, the emacs-style notation is used to denote keystrokes. Control keys are denoted by C-_k_e_y, e.g., C-n means Control-N. Similarly, _m_e_t_a keys are denoted by M-_k_e_y, so M-x means Meta-X. (On keyboards without a _m_e_t_a key, M-_x means ESC _x, i.e., press the Escape key then the _x key. This makes ESC the _m_e_t_a _p_r_e_f_i_x. The combination M-C-_x means ESC-Control-_x, or press the Escape key then hold the Control key while pressing the _x key.) The default key-bindings may be changed with an ~/._i_n_p_u_t_r_c file. The value of the shell variable IIIINNNNPPPPUUUUTTTTRRRRCCCC, if set, is used instead of ~/._i_n_p_u_t_r_c. Other programs that use this library may add their own commands and bindings. For example, placing M-Control-u: universal-argument or C-Meta-u: universal-argument into the ~/._i_n_p_u_t_r_c would make M-C-u execute the readline command _u_n_i_v_e_r_s_a_l-_a_r_g_u_m_e_n_t. The following symbolic character names are recognized: _R_U_B_O_U_T, _D_E_L, _E_S_C, _L_F_D, _N_E_W_L_I_N_E, _R_E_T, _R_E_T_U_R_N, _S_P_C, _S_P_A_C_E, and _T_A_B. In addition to command names, readline allows keys to be bound to a string that is inserted when the key is pressed (a _m_a_c_r_o). Readline is customized by putting commands in an initialization file. The name of this file is taken from the value of the IIIINNNNPPPPUUUUTTTTRRRRCCCC variable. If that variable is unset, the default is ~/._i_n_p_u_t_r_c. When a program which uses the readline library starts up, the init file is read, and the key bindings and variables are set. There are only a few basic constructs allowed in the readline init file. Blank lines are ignored. Lines beginning with a #### are comments. Lines beginning with a $$$$ indicate conditional constructs. Other lines denote key bindings and variable settings. The syntax for controlling key bindings in the ~/._i_n_p_u_t_r_c file is simple. All that is required is the name of the command or the text of a macro and a key sequence to which it should be bound. The name may be specified in one of two ways: as a symbolic key name, possibly with _M_e_t_a- or _C_o_n_t_r_o_l- prefixes, or as a key sequence. When using the form kkkkeeeeyyyynnnnaaaammmmeeee:_f_u_n_c_t_i_o_n-_n_a_m_e or _m_a_c_r_o, _k_e_y_n_a_m_e is the name of a key spelled out in English. For example: Page 28 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) Control-u: universal-argument Meta-Rubout: backward-kill-word Control-o: ">&output" In the above example, _C-_u is bound to the function uuuunnnniiiivvvveeeerrrrssssaaaallll----aaaarrrrgggguuuummmmeeeennnntttt, _M-_D_E_L is bound to the function bbbbaaaacccckkkkwwwwaaaarrrrdddd----kkkkiiiillllllll----wwwwoooorrrrdddd, and _C-_o is bound to run the macro expressed on the right hand side (that is, to insert the text >&_o_u_t_p_u_t into the line). In the second form, """"kkkkeeeeyyyysssseeeeqqqq"""":_f_u_n_c_t_i_o_n-_n_a_m_e or _m_a_c_r_o, kkkkeeeeyyyysssseeeeqqqq differs from kkkkeeeeyyyynnnnaaaammmmeeee above in that strings denoting an entire key sequence may be specified by placing the sequence within double quotes. Some GNU Emacs style key escapes can be used, as in the following example. "\C-u": universal-argument "\C-x\C-r": re-read-init-file "\e[11~": "Function Key 1" In this example, _C-_u is again bound to the function uuuunnnniiiivvvveeeerrrrssssaaaallll----aaaarrrrgggguuuummmmeeeennnntttt. _C-_x _C-_r is bound to the function rrrreeee----rrrreeeeaaaadddd----iiiinnnniiiitttt----ffffiiiilllleeee, and _E_S_C [ _1 _1 ~ is bound to insert the text FFFFuuuunnnnccccttttiiiioooonnnn KKKKeeeeyyyy 1111. The full set of escape sequences is \\\\CCCC---- control prefix \\\\MMMM---- meta prefix \\\\eeee an escape character \\\\\\\\ backslash \\\\"""" literal " \\\\'''' literal ' When entering the text of a macro, single or double quotes should be used to indicate a macro definition. Unquoted text is assumed to be a function name. Backslash will quote any character in the macro text, including " and '. BBBBaaaasssshhhh allows the current readline key bindings to be displayed or modified with the bbbbiiiinnnndddd builtin command. The editing mode may be switched during interactive use by using the ----oooo option to the sssseeeetttt builtin command (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). Readline has variables that can be used to further customize its behavior. A variable may be set in the _i_n_p_u_t_r_c file with a statement of the form Page 29 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) sssseeeetttt _v_a_r_i_a_b_l_e-_n_a_m_e _v_a_l_u_e Except where noted, readline variables can take the values OOOOnnnn or OOOOffffffff. The variables and their default values are: hhhhoooorrrriiiizzzzoooonnnnttttaaaallll----ssssccccrrrroooollllllll----mmmmooooddddeeee ((((OOOOffffffff)))) When set to OOOOnnnn, makes readline use a single line for display, scrolling the input horizontally on a single screen line when it becomes longer than the screen width rather than wrapping to a new line. eeeeddddiiiittttiiiinnnngggg----mmmmooooddddeeee ((((eeeemmmmaaaaccccssss)))) Controls whether readline begins with a set of key bindings similar to _e_m_a_c_s or _v_i. eeeeddddiiiittttiiiinnnngggg----mmmmooooddddeeee can be set to either eeeemmmmaaaaccccssss or vvvviiii. mmmmaaaarrrrkkkk----mmmmooooddddiiiiffffiiiieeeedddd----lllliiiinnnneeeessss ((((OOOOffffffff)))) If set to OOOOnnnn, history lines that have been modified are displayed with a preceding asterisk (****). bbbbeeeellllllll----ssssttttyyyylllleeee ((((aaaauuuuddddiiiibbbblllleeee)))) Controls what happens when readline wants to ring the terminal bell. If set to nnnnoooonnnneeee, readline never rings the bell. If set to vvvviiiissssiiiibbbblllleeee, readline uses a visible bell if one is available. If set to aaaauuuuddddiiiibbbblllleeee, readline attempts to ring the terminal's bell. ccccoooommmmmmmmeeeennnntttt----bbbbeeeeggggiiiinnnn ((((````````####'''''''')))) The string that is inserted in vvvviiii mode when the vvvviiii----ccccoooommmmmmmmeeeennnntttt command is executed. mmmmeeeettttaaaa----ffffllllaaaagggg ((((OOOOffffffff)))) If set to OOOOnnnn, readline will enable eight-bit input (that is, it will not strip the high bit from the characters it reads), regardless of what the terminal claims it can support. ccccoooonnnnvvvveeeerrrrtttt----mmmmeeeettttaaaa ((((OOOOnnnn)))) If set to OOOOnnnn, readline will convert characters with the eighth bit set to an ASCII key sequence by stripping the eighth bit and prepending an escape character (in effect, using escape as the _m_e_t_a _p_r_e_f_i_x). oooouuuuttttppppuuuutttt----mmmmeeeettttaaaa ((((OOOOffffffff)))) If set to OOOOnnnn, readline will display characters with the eighth bit set directly rather than as a meta-prefixed escape sequence. ccccoooommmmpppplllleeeettttiiiioooonnnn----qqqquuuueeeerrrryyyy----iiiitttteeeemmmmssss ((((111100000000)))) This determines when the user is queried about viewing the number of possible completions generated by the ppppoooossssssssiiiibbbblllleeee----ccccoooommmmpppplllleeeettttiiiioooonnnnssss command. It may be set to any integer value greater than or equal to zero. If the number of possible completions is greater than or equal to the value of this variable, the user is asked whether or not he wishes to view them; otherwise they are simply listed on the terminal. kkkkeeeeyyyymmmmaaaapppp ((((eeeemmmmaaaaccccssss)))) Set the current readline keymap. The set of legal keymap names is _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, Page 30 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) _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. The default value is _e_m_a_c_s; the value of eeeeddddiiiittttiiiinnnngggg----mmmmooooddddeeee also affects the default keymap. sssshhhhoooowwww----aaaallllllll----iiiiffff----aaaammmmbbbbiiiigggguuuuoooouuuussss ((((OOOOffffffff)))) This alters the default behavior of the completion functions. If set to oooonnnn, words which have more than one possible completion cause the matches to be listed immediately instead of ringing the bell. eeeexxxxppppaaaannnndddd----ttttiiiillllddddeeee ((((OOOOffffffff)))) If set to oooonnnn, tilde expansion is performed when readline attempts word completion. Readline implements a facility similar in spirit to the conditional compilation features of the C preprocessor which allows key bindings and variable settings to be performed as the result of tests. There are three parser directives used. $$$$iiiiffff The $$$$iiiiffff construct allows bindings to be made based on the editing mode, the terminal being used, or the application using readline. The text of the test extends to the end of the line; no characters are required to isolate it. mmmmooooddddeeee The mmmmooooddddeeee==== form of the $$$$iiiiffff directive is used to test whether readline is in emacs or vi mode. This may be used in conjunction with the sssseeeetttt kkkkeeeeyyyymmmmaaaapppp command, for instance, to set bindings in the _e_m_a_c_s-_s_t_a_n_d_a_r_d and _e_m_a_c_s-_c_t_l_x keymaps only if readline is starting out in emacs mode. tttteeeerrrrmmmm The tttteeeerrrrmmmm==== form may be used to include terminal- specific key bindings, perhaps to bind the key sequences output by the terminal's function keys. The word on the right side of the ==== is tested against the full name of the terminal and the portion of the terminal name before the first ----. This allows _s_u_n to match both _s_u_n and _s_u_n-_c_m_d, for instance. aaaapppppppplllliiiiccccaaaattttiiiioooonnnn The aaaapppppppplllliiiiccccaaaattttiiiioooonnnn construct is used to include application-specific settings. Each program using the readline library sets the _a_p_p_l_i_c_a_t_i_o_n _n_a_m_e, and an initialization file can test for a particular value. This could be used to bind key sequences to functions useful for a specific program. For instance, the following command adds a key sequence that quotes the current or previous word in Bash: $$$$iiiiffff Bash Page 31 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) # Quote the current or previous word "\C-xq": "\eb\"\ef\"" $$$$eeeennnnddddiiiiffff $$$$eeeennnnddddiiiiffff This command, as you saw in the previous example, terminates an $$$$iiiiffff command. $$$$eeeellllsssseeee Commands in this branch of the $$$$iiiiffff directive are executed if the test fails. Readline commands may be given numeric _a_r_g_u_m_e_n_t_s, which normally act as a repeat count. Sometimes, however, it is the sign of the argument that is significant. Passing a negative argument to a command that acts in the forward direction (e.g., kkkkiiiillllllll----lllliiiinnnneeee) causes that command to act in a backward direction. Commands whose behavior with arguments deviates from this are noted. When a command is described as _k_i_l_l_i_n_g text, the text deleted is saved for possible future retrieval (_y_a_n_k_i_n_g). The killed text is saved in a _k_i_l_l-_r_i_n_g. Consecutive kills cause the text to be accumulated into one unit, which can be yanked all at once. Commands which do not kill text separate the chunks of text on the kill-ring. The following is a list of the names of the commands and the default key sequences to which they are bound. CCCCoooommmmmmmmaaaannnnddddssss ffffoooorrrr MMMMoooovvvviiiinnnngggg bbbbeeeeggggiiiinnnnnnnniiiinnnngggg----ooooffff----lllliiiinnnneeee ((((CCCC----aaaa)))) Move to the start of the current line. eeeennnndddd----ooooffff----lllliiiinnnneeee ((((CCCC----eeee)))) Move to the end of the line. ffffoooorrrrwwwwaaaarrrrdddd----cccchhhhaaaarrrr ((((CCCC----ffff)))) Move forward a character. bbbbaaaacccckkkkwwwwaaaarrrrdddd----cccchhhhaaaarrrr ((((CCCC----bbbb)))) Move back a character. ffffoooorrrrwwwwaaaarrrrdddd----wwwwoooorrrrdddd ((((MMMM----ffff)))) Move forward to the end of the next word. Words are composed of alphanumeric characters (letters and digits). bbbbaaaacccckkkkwwwwaaaarrrrdddd----wwwwoooorrrrdddd ((((MMMM----bbbb)))) Move back to the start of this, or the previous, word. Words are composed of alphanumeric characters (letters and digits). cccclllleeeeaaaarrrr----ssssccccrrrreeeeeeeennnn ((((CCCC----llll)))) Clear the screen leaving the current line at the top of the screen. With an argument, refresh the current line without clearing the screen. rrrreeeeddddrrrraaaawwww----ccccuuuurrrrrrrreeeennnntttt----lllliiiinnnneeee Page 32 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) Refresh the current line. By default, this is unbound. CCCCoooommmmmmmmaaaannnnddddssss ffffoooorrrr MMMMaaaannnniiiippppuuuullllaaaattttiiiinnnngggg tttthhhheeee HHHHiiiissssttttoooorrrryyyy aaaacccccccceeeepppptttt----lllliiiinnnneeee ((((NNNNeeeewwwwlllliiiinnnneeee,,,, RRRReeeettttuuuurrrrnnnn)))) Accept the line regardless of where the cursor is. If this line is non-empty, add it to the history list according to the state of the HHHHIIIISSSSTTTTCCCCOOOONNNNTTTTRRRROOOOLLLL variable. If the line is a modified history line, then restore the history line to its original state. pppprrrreeeevvvviiiioooouuuussss----hhhhiiiissssttttoooorrrryyyy ((((CCCC----pppp)))) Fetch the previous command from the history list, moving back in the list. nnnneeeexxxxtttt----hhhhiiiissssttttoooorrrryyyy ((((CCCC----nnnn)))) Fetch the next command from the history list, moving forward in the list. bbbbeeeeggggiiiinnnnnnnniiiinnnngggg----ooooffff----hhhhiiiissssttttoooorrrryyyy ((((MMMM----<<<<)))) Move to the first line in the history. eeeennnndddd----ooooffff----hhhhiiiissssttttoooorrrryyyy ((((MMMM---->>>>)))) Move to the end of the input history, i.e., the line currently being entered. rrrreeeevvvveeeerrrrsssseeee----sssseeeeaaaarrrrcccchhhh----hhhhiiiissssttttoooorrrryyyy ((((CCCC----rrrr)))) Search backward starting at the current line and moving `up' through the history as necessary. This is an incremental search. ffffoooorrrrwwwwaaaarrrrdddd----sssseeeeaaaarrrrcccchhhh----hhhhiiiissssttttoooorrrryyyy ((((CCCC----ssss)))) Search forward starting at the current line and moving `down' through the history as necessary. This is an incremental search. nnnnoooonnnn----iiiinnnnccccrrrreeeemmmmeeeennnnttttaaaallll----rrrreeeevvvveeeerrrrsssseeee----sssseeeeaaaarrrrcccchhhh----hhhhiiiissssttttoooorrrryyyy ((((MMMM----pppp)))) Search backward through the history starting at the current line using a non-incremental search for a string supplied by the user. nnnnoooonnnn----iiiinnnnccccrrrreeeemmmmeeeennnnttttaaaallll----ffffoooorrrrwwwwaaaarrrrdddd----sssseeeeaaaarrrrcccchhhh----hhhhiiiissssttttoooorrrryyyy ((((MMMM----nnnn)))) Search forward through the history using a non-incremental search for a string supplied by the user. hhhhiiiissssttttoooorrrryyyy----sssseeeeaaaarrrrcccchhhh----ffffoooorrrrwwwwaaaarrrrdddd Search forward through the history for the string of characters between the start of the current line and the current point. This is a non-incremental search. By default, this command is unbound. hhhhiiiissssttttoooorrrryyyy----sssseeeeaaaarrrrcccchhhh----bbbbaaaacccckkkkwwwwaaaarrrrdddd Search backward through the history for the string of characters between the start of the current line and the current point. This is a non-incremental search. By default, this command is unbound. yyyyaaaannnnkkkk----nnnntttthhhh----aaaarrrrgggg ((((MMMM----CCCC----yyyy)))) Insert the first argument to the previous command (usually the second word on the previous line) at point (the current cursor position). With an argument _n, insert the _nth word from the previous command (the words in the previous command begin with word 0). A Page 33 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) negative argument inserts the _nth word from the end of the previous command. yyyyaaaannnnkkkk----llllaaaasssstttt----aaaarrrrgggg ((((MMMM----....,,,, MMMM----____)))) Insert the last argument to the previous command (the last word on the previous line). With an argument, behave exactly like @code{yank-nth-arg}. sssshhhheeeellllllll----eeeexxxxppppaaaannnndddd----lllliiiinnnneeee ((((MMMM----CCCC----eeee)))) Expand the line the way the shell does when it reads it. This performs alias and history expansion as well as all of the shell word expansions. See HHHHIIIISSSSTTTTOOOORRRRYYYY EEEEXXXXPPPPAAAANNNNSSSSIIIIOOOONNNN below for a description of history expansion. hhhhiiiissssttttoooorrrryyyy----eeeexxxxppppaaaannnndddd----lllliiiinnnneeee ((((MMMM----^^^^)))) Perform history expansion on the current line. See HHHHIIIISSSSTTTTOOOORRRRYYYY EEEEXXXXPPPPAAAANNNNSSSSIIIIOOOONNNN below for a description of history expansion. iiiinnnnsssseeeerrrrtttt----llllaaaasssstttt----aaaarrrrgggguuuummmmeeeennnntttt ((((MMMM----....,,,, MMMM----____)))) A synonym for yyyyaaaannnnkkkk----llllaaaasssstttt----aaaarrrrgggg. ooooppppeeeerrrraaaatttteeee----aaaannnndddd----ggggeeeetttt----nnnneeeexxxxtttt ((((CCCC----oooo)))) Accept the current line for execution and fetch the next line relative to the current line from the history for editing. Any argument is ignored. CCCCoooommmmmmmmaaaannnnddddssss ffffoooorrrr CCCChhhhaaaannnnggggiiiinnnngggg TTTTeeeexxxxtttt ddddeeeelllleeeetttteeee----cccchhhhaaaarrrr ((((CCCC----dddd)))) Delete the character under the cursor. If point is at the beginning of the line, there are no characters in the line, and the last character typed was not CCCC----dddd, then return EEEEOOOOFFFF. bbbbaaaacccckkkkwwwwaaaarrrrdddd----ddddeeeelllleeeetttteeee----cccchhhhaaaarrrr ((((RRRRuuuubbbboooouuuutttt)))) Delete the character behind the cursor. When given a numeric argument, save the deleted text on the kill-ring. qqqquuuuooootttteeeedddd----iiiinnnnsssseeeerrrrtttt ((((CCCC----qqqq,,,, CCCC----vvvv)))) Add the next character that you type to the line verbatim. This is how to insert characters like CCCC----qqqq, for example. ttttaaaabbbb----iiiinnnnsssseeeerrrrtttt ((((CCCC----vvvv TTTTAAAABBBB)))) Insert a tab character. sssseeeellllffff----iiiinnnnsssseeeerrrrtttt ((((aaaa,,,, bbbb,,,, AAAA,,,, 1111,,,, !!!!,,,, ............)))) Insert the character typed. ttttrrrraaaannnnssssppppoooosssseeee----cccchhhhaaaarrrrssss ((((CCCC----tttt)))) Drag the character before point forward over the character at point. Point moves forward as well. If point is at the end of the line, then transpose the two characters before point. Negative arguments don't work. ttttrrrraaaannnnssssppppoooosssseeee----wwwwoooorrrrddddssss ((((MMMM----tttt)))) Drag the word behind the cursor past the word in front of the cursor moving the cursor over that word as well. uuuuppppccccaaaasssseeee----wwwwoooorrrrdddd ((((MMMM----uuuu)))) Uppercase the current (or following) word. With a negative argument, do the previous word, but do not Page 34 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) move point. ddddoooowwwwnnnnccccaaaasssseeee----wwwwoooorrrrdddd ((((MMMM----llll)))) Lowercase the current (or following) word. With a negative argument, do the previous word, but do not move point. ccccaaaappppiiiittttaaaalllliiiizzzzeeee----wwwwoooorrrrdddd ((((MMMM----cccc)))) Capitalize the current (or following) word. With a negative argument, do the previous word, but do not move point. KKKKiiiilllllllliiiinnnngggg aaaannnndddd YYYYaaaannnnkkkkiiiinnnngggg kkkkiiiillllllll----lllliiiinnnneeee ((((CCCC----kkkk)))) Kill the text from the current cursor position to the end of the line. bbbbaaaacccckkkkwwwwaaaarrrrdddd----kkkkiiiillllllll----lllliiiinnnneeee ((((CCCC----xxxx CCCC----RRRRuuuubbbboooouuuutttt)))) Kill backward to the beginning of the line. uuuunnnniiiixxxx----lllliiiinnnneeee----ddddiiiissssccccaaaarrrrdddd ((((CCCC----uuuu)))) Kill backward from point to the beginning of the line. kkkkiiiillllllll----wwwwhhhhoooolllleeee----lllliiiinnnneeee Kill all characters on the current line, no matter where the cursor is. By default, this is unbound. kkkkiiiillllllll----wwwwoooorrrrdddd ((((MMMM----dddd)))) Kill from the cursor to the end of the current word, or if between words, to the end of the next word. Word boundaries are the same as those used by ffffoooorrrrwwwwaaaarrrrdddd----wwwwoooorrrrdddd. bbbbaaaacccckkkkwwwwaaaarrrrdddd----kkkkiiiillllllll----wwwwoooorrrrdddd ((((MMMM----RRRRuuuubbbboooouuuutttt)))) Kill the word behind the cursor. Word boundaries are the same as those used by bbbbaaaacccckkkkwwwwaaaarrrrdddd----wwwwoooorrrrdddd. uuuunnnniiiixxxx----wwwwoooorrrrdddd----rrrruuuubbbboooouuuutttt ((((CCCC----wwww)))) Kill the word behind the cursor, using white space as a word boundary. The word boundaries are different from backward-kill-word. ddddeeeelllleeeetttteeee----hhhhoooorrrriiiizzzzoooonnnnttttaaaallll----ssssppppaaaacccceeee Delete all spaces and tabs around point. By default, this is unbound. yyyyaaaannnnkkkk ((((CCCC----yyyy)))) Yank the top of the kill ring into the buffer at the cursor. yyyyaaaannnnkkkk----ppppoooopppp ((((MMMM----yyyy)))) Rotate the kill-ring, and yank the new top. Only works following yyyyaaaannnnkkkk or yyyyaaaannnnkkkk----ppppoooopppp. NNNNuuuummmmeeeerrrriiiicccc AAAArrrrgggguuuummmmeeeennnnttttssss ddddiiiiggggiiiitttt----aaaarrrrgggguuuummmmeeeennnntttt ((((MMMM----0000,,,, MMMM----1111,,,, ............,,,, MMMM--------)))) Add this digit to the argument already accumulating, or start a new argument. M-- starts a negative argument. uuuunnnniiiivvvveeeerrrrssssaaaallll----aaaarrrrgggguuuummmmeeeennnntttt Each time this is executed, the argument count is multiplied by four. The argument count is initially one, so executing this function the first time makes the argument count four. By default, this is not bound to a key. Page 35 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) CCCCoooommmmpppplllleeeettttiiiinnnngggg ccccoooommmmpppplllleeeetttteeee ((((TTTTAAAABBBB)))) Attempt to perform completion on the text before point. BBBBaaaasssshhhh attempts completion treating the text as a variable (if the text begins with $$$$), username (if the text begins with ~~~~), hostname (if the text begins with @@@@), or command (including aliases and functions) in turn. If none of these produces a match, filename completion is attempted. ppppoooossssssssiiiibbbblllleeee----ccccoooommmmpppplllleeeettttiiiioooonnnnssss ((((MMMM----????)))) List the possible completions of the text before point. iiiinnnnsssseeeerrrrtttt----ccccoooommmmpppplllleeeettttiiiioooonnnnssss Insert all completions of the text before point that would have been generated by ppppoooossssssssiiiibbbblllleeee----ccccoooommmmpppplllleeeettttiiiioooonnnnssss. By default, this is not bound to a key. ccccoooommmmpppplllleeeetttteeee----ffffiiiilllleeeennnnaaaammmmeeee ((((MMMM----////)))) Attempt filename completion on the text before point. ppppoooossssssssiiiibbbblllleeee----ffffiiiilllleeeennnnaaaammmmeeee----ccccoooommmmpppplllleeeettttiiiioooonnnnssss ((((CCCC----xxxx ////)))) List the possible completions of the text before point, treating it as a filename. ccccoooommmmpppplllleeeetttteeee----uuuusssseeeerrrrnnnnaaaammmmeeee ((((MMMM----~~~~)))) Attempt completion on the text before point, treating it as a username. ppppoooossssssssiiiibbbblllleeee----uuuusssseeeerrrrnnnnaaaammmmeeee----ccccoooommmmpppplllleeeettttiiiioooonnnnssss ((((CCCC----xxxx ~~~~)))) List the possible completions of the text before point, treating it as a username. ccccoooommmmpppplllleeeetttteeee----vvvvaaaarrrriiiiaaaabbbblllleeee ((((MMMM----$$$$)))) Attempt completion on the text before point, treating it as a shell variable. ppppoooossssssssiiiibbbblllleeee----vvvvaaaarrrriiiiaaaabbbblllleeee----ccccoooommmmpppplllleeeettttiiiioooonnnnssss ((((CCCC----xxxx $$$$)))) List the possible completions of the text before point, treating it as a shell variable. ccccoooommmmpppplllleeeetttteeee----hhhhoooossssttttnnnnaaaammmmeeee ((((MMMM----@@@@)))) Attempt completion on the text before point, treating it as a hostname. ppppoooossssssssiiiibbbblllleeee----hhhhoooossssttttnnnnaaaammmmeeee----ccccoooommmmpppplllleeeettttiiiioooonnnnssss ((((CCCC----xxxx @@@@)))) List the possible completions of the text before point, treating it as a hostname. ccccoooommmmpppplllleeeetttteeee----ccccoooommmmmmmmaaaannnndddd ((((MMMM----!!!!)))) Attempt completion on the text before point, treating it as a command name. Command completion attempts to match the text against aliases, reserved words, shell functions, builtins, and finally executable filenames, in that order. ppppoooossssssssiiiibbbblllleeee----ccccoooommmmmmmmaaaannnndddd----ccccoooommmmpppplllleeeettttiiiioooonnnnssss ((((CCCC----xxxx !!!!)))) List the possible completions of the text before point, treating it as a command name. ddddyyyynnnnaaaammmmiiiicccc----ccccoooommmmpppplllleeeetttteeee----hhhhiiiissssttttoooorrrryyyy ((((MMMM----TTTTAAAABBBB)))) Attempt completion on the text before point, comparing the text against lines from the history list for possible completion matches. ccccoooommmmpppplllleeeetttteeee----iiiinnnnttttoooo----bbbbrrrraaaacccceeeessss ((((MMMM----{{{{)))) Page 36 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) Perform filename completion and return the list of possible completions enclosed within braces so the list is available to the shell (see BBBBrrrraaaacccceeee EEEExxxxppppaaaannnnssssiiiioooonnnn above). KKKKeeeeyyyybbbbooooaaaarrrrdddd MMMMaaaaccccrrrroooossss ssssttttaaaarrrrtttt----kkkkbbbbdddd----mmmmaaaaccccrrrroooo ((((CCCC----xxxx (((()))) Begin saving the characters typed into the current keyboard macro. eeeennnndddd----kkkkbbbbdddd----mmmmaaaaccccrrrroooo ((((CCCC----xxxx )))))))) Stop saving the characters typed into the current keyboard macro and save the definition. ccccaaaallllllll----llllaaaasssstttt----kkkkbbbbdddd----mmmmaaaaccccrrrroooo ((((CCCC----xxxx eeee)))) Re-execute the last keyboard macro defined, by making the characters in the macro appear as if typed at the keyboard. MMMMiiiisssscccceeeellllllllaaaannnneeeeoooouuuussss rrrreeee----rrrreeeeaaaadddd----iiiinnnniiiitttt----ffffiiiilllleeee ((((CCCC----xxxx CCCC----rrrr)))) Read in the contents of your init file, and incorporate any bindings or variable assignments found there. aaaabbbboooorrrrtttt ((((CCCC----gggg)))) Abort the current editing command and ring the terminal's bell (subject to the setting of bbbbeeeellllllll----ssssttttyyyylllleeee). ddddoooo----uuuuppppppppeeeerrrrccccaaaasssseeee----vvvveeeerrrrssssiiiioooonnnn ((((MMMM----aaaa,,,, MMMM----bbbb,,,, ............)))) Run the command that is bound to the corresponding uppercase character. pppprrrreeeeffffiiiixxxx----mmmmeeeettttaaaa ((((EEEESSSSCCCC)))) Metafy the next character typed. EEEESSSSCCCC ffff is equivalent to MMMMeeeettttaaaa----ffff. uuuunnnnddddoooo ((((CCCC----____,,,, CCCC----xxxx CCCC----uuuu)))) Incremental undo, separately remembered for each line. rrrreeeevvvveeeerrrrtttt----lllliiiinnnneeee ((((MMMM----rrrr)))) Undo all changes made to this line. This is like typing the uuuunnnnddddoooo command enough times to return the line to its initial state. ttttiiiillllddddeeee----eeeexxxxppppaaaannnndddd ((((MMMM----~~~~)))) Perform tilde expansion on the current word. dddduuuummmmpppp----ffffuuuunnnnccccttttiiiioooonnnnssss Print all of the functions and their key bindings to the readline output stream. If a numeric argument is supplied, the output is formatted in such a way that it can be made part of an _i_n_p_u_t_r_c file. ddddiiiissssppppllllaaaayyyy----sssshhhheeeellllllll----vvvveeeerrrrssssiiiioooonnnn ((((CCCC----xxxx CCCC----vvvv)))) Display version information about the current instance of bbbbaaaasssshhhh. eeeemmmmaaaaccccssss----eeeeddddiiiittttiiiinnnngggg----mmmmooooddddeeee ((((CCCC----eeee)))) When in vvvviiii editing mode, this causes a switch to eeeemmmmaaaaccccssss editing mode. HHHHIIIISSSSTTTTOOOORRRRYYYY When interactive, the shell provides access to the _c_o_m_m_a_n_d _h_i_s_t_o_r_y, the list of commands previously typed. The text of Page 37 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) the last HHHHIIIISSSSTTTTSSSSIIIIZZZZEEEE commands (default 500) is saved in a history list. The shell stores each command in the history list prior to parameter and variable expansion (see EEEEXXXXPPPPAAAANNNNSSSSIIIIOOOONNNN above) but after history expansion is performed, subject to the values of the shell variables ccccoooommmmmmmmaaaannnndddd____oooorrrriiiieeeennnntttteeeedddd____hhhhiiiissssttttoooorrrryyyy and HHHHIIIISSSSTTTTCCCCOOOONNNNTTTTRRRROOOOLLLL. On startup, the history is initialized from the file named by the variable HHHHIIIISSSSTTTTFFFFIIIILLLLEEEE (default ~/._b_a_s_h__h_i_s_t_o_r_y). HHHHIIIISSSSTTTTFFFFIIIILLLLEEEE is truncated, if necessary, to contain no more than HHHHIIIISSSSTTTTFFFFIIIILLLLEEEESSSSIIIIZZZZEEEE lines. The builtin command ffffcccc (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below) may be used to list or edit and re-execute a portion of the history list. The hhhhiiiissssttttoooorrrryyyy builtin can be used to display the history list and manipulate the history file. When using the command-line editing, search commands are available in each editing mode that provide access to the history list. When an interactive shell exits, the last HHHHIIIISSSSTTTTSSSSIIIIZZZZEEEE lines are copied from the history list to HHHHIIIISSSSTTTTFFFFIIIILLLLEEEE. If HHHHIIIISSSSTTTTFFFFIIIILLLLEEEE is unset, or if the history file is unwritable, the history is not saved. HHHHIIIISSSSTTTTOOOORRRRYYYY EEEEXXXXPPPPAAAANNNNSSSSIIIIOOOONNNN The shell supports a history expansion feature that is similar to the history expansion in ccccsssshhhh.... This section describes what syntax features are available. This feature is enabled by default for interactive shells, and can be disabled using the ++++HHHH option to the sssseeeetttt builtin command (see SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS below). Non-interactive shells do not perform history expansion. History expansion is performed immediately after a complete line is read, before the shell breaks it into words. It takes place in two parts. The first is to determine which line from the previous history to use during substitution. The second is to select portions of that line for inclusion into the current one. The line selected from the previous history is the _e_v_e_n_t, and the portions of that line that are acted upon are _w_o_r_d_s. The line is broken into words in the same fashion as when reading input, so that several _m_e_t_a_c_h_a_r_a_c_t_e_r-separated words surrounded by quotes are considered as one word. Only backslash (\\\\) and single quotes can quote the history escape character, which is !!!! by default. The shell allows control of the various characters used by the history expansion mechanism (see the description of hhhhiiiissssttttcccchhhhaaaarrrrssss above under SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss). EEEEvvvveeeennnntttt DDDDeeeessssiiiiggggnnnnaaaattttoooorrrrssss An event designator is a reference to a command line entry in the history list. !!!! Start a history substitution, except when followed by a Page 38 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) bbbbllllaaaannnnkkkk, newline, = or (. !!!!!!!! Refer to the previous command. This is a synonym for `!-1'. !!!!_n Refer to command line _n. !!!!----_n Refer to the current command line minus _n. !!!!_s_t_r_i_n_g Refer to the most recent command starting with _s_t_r_i_n_g. !!!!????_s_t_r_i_n_g[[[[????]]]] Refer to the most recent command containing _s_t_r_i_n_g. ^^^^_s_t_r_i_n_g_1^^^^_s_t_r_i_n_g_2^^^^ Quick substitution. Repeat the last command, replacing _s_t_r_i_n_g_1 with _s_t_r_i_n_g_2. Equivalent to ``!!:s/_s_t_r_i_n_g_1/_s_t_r_i_n_g_2/'' (see MMMMooooddddiiiiffffiiiieeeerrrrssss below). !!!!#### The entire command line typed so far. WWWWoooorrrrdddd DDDDeeeessssiiiiggggnnnnaaaattttoooorrrrssss A :::: separates the event specification from the word designator. It can be omitted if the word designator begins with a ^^^^, $$$$, ****, or %%%%. Words are numbered from the beginning of the line, with the first word being denoted by a 0 (zero). 0000 ((((zzzzeeeerrrroooo)))) The zeroth word. For the shell, this is the command word. _n The _nth word. ^^^^ The first argument. That is, word 1. $$$$ The last argument. %%%% The word matched by the most recent `?_s_t_r_i_n_g?' search. _x----_y A range of words; `-_y' abbreviates `0-_y'. **** All of the words but the zeroth. This is a synonym for `_1-$'. It is not an error to use **** if there is just one word in the event; the empty string is returned in that case. xxxx**** Abbreviates _x-$. xxxx---- Abbreviates _x-$ like xxxx****, but omits the last word. MMMMooooddddiiiiffffiiiieeeerrrrssss After the optional word designator, you can add a sequence of one or more of the following modifiers, each preceded by a `:'. hhhh Remove a trailing pathname component, leaving only the head. rrrr Remove a trailing suffix of the form ._x_x_x, leaving the basename. eeee Remove all but the trailing suffix. tttt Remove all leading pathname components, leaving the tail. pppp Print the new command but do not execute it. qqqq Quote the substituted words, escaping further substitutions. Page 39 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) xxxx Quote the substituted words as with qqqq, but break into words at bbbbllllaaaannnnkkkkssss and newlines. ssss////_o_l_d////_n_e_w//// Substitute _n_e_w for the first occurrence of _o_l_d in the event line. Any delimiter can be used in place of /. The final delimiter is optional if it is the last character of the event line. The delimiter may be quoted in _o_l_d and _n_e_w with a single backslash. If & appears in _n_e_w, it is replaced by _o_l_d. A single backslash will quote the &. &&&& Repeat the previous substitution. gggg Cause changes to be applied over the entire event line. This is used in conjunction with `::::ssss' (e.g., `::::ggggssss////_o_l_d////_n_e_w////') or `::::&&&&'. If used with `::::ssss', any delimiter can be used in place of /, and the final delimiter is optional if it is the last character of the event line. AAAARRRRIIIITTTTHHHHMMMMEEEETTTTIIIICCCC EEEEVVVVAAAALLLLUUUUAAAATTTTIIIIOOOONNNN The shell allows arithmetic expressions to be evaluated, under certain circumstances (see the lllleeeetttt builtin command and AAAArrrriiiitttthhhhmmmmeeeettttiiiicccc EEEExxxxppppaaaannnnssssiiiioooonnnn). Evaluation is done in long integers with no check for overflow, though division by 0 is trapped and flagged as an error. The following list of operators is grouped into levels of equal-precedence operators. The levels are listed in order of decreasing precedence. ---- ++++ unary minus and plus !!!! ~~~~ logical and bitwise negation **** //// %%%% multiplication, division, remainder ++++ ---- addition, subtraction <<<<<<<< >>>>>>>> left and right bitwise shifts <<<<==== >>>>==== <<<< >>>> comparison ======== !!!!==== equality and inequality &&&& bitwise AND ^^^^ bitwise exclusive OR |||| bitwise OR &&&&&&&& logical AND |||||||| logical OR ==== ****==== ////==== %%%%==== ++++==== ----==== assignment Shell variables are allowed as operands; parameter expansion is performed before the expression is evaluated. The value of a parameter is coerced to a long integer within an expression. A shell variable need not have its integer attribute turned on to be used in an expression. Page 40 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) Constants with a leading 0 are interpreted as octal numbers. A leading _0_x or _0_X denotes hexadecimal. Otherwise, numbers take the form [_b_a_s_e#]n, where _b_a_s_e is a decimal number between 2 and 36 representing the arithmetic base, and _n is a number in that base. If _b_a_s_e is omitted, then base 10 is used. Operators are evaluated in order of precedence. Sub- expressions in parentheses are evaluated first and may override the precedence rules above. SSSSHHHHEEEELLLLLLLL BBBBUUUUIIIILLLLTTTTIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS :::: [_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] ssssoooouuuurrrrcccceeee _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 executed from _f_i_l_e_n_a_m_e. If _f_i_l_e_n_a_m_e does not contain a slash, pathnames in PPPPAAAATTTTHHHH are used to find the directory containing _f_i_l_e_n_a_m_e. The file searched for in PPPPAAAATTTTHHHH need not be executable. The current directory is searched if no file is found in PPPPAAAATTTTHHHH. If any _a_r_g_u_m_e_n_t_s are supplied, they become the positional parameters when _f_i_l_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. aaaalllliiiiaaaassss [_n_a_m_e[=_v_a_l_u_e] ...] AAAAlllliiiiaaaassss with no arguments prints the list of aliases in the form _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 supplied, the name and value of the alias is printed. AAAAlllliiiiaaaassss returns true unless a _n_a_m_e is given for which no alias has been defined. bbbbgggg [_j_o_b_s_p_e_c] Place _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. bbbbgggg _j_o_b_s_p_e_c returns 0 unless run when job control is disabled or, when run with job control enabled, if _j_o_b_s_p_e_c was not found or started without job control. Page 41 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) bbbbiiiinnnndddd [----mmmm _k_e_y_m_a_p] [----llllvvvvdddd] [----qqqq _n_a_m_e] bbbbiiiinnnndddd [----mmmm _k_e_y_m_a_p] ----ffff _f_i_l_e_n_a_m_e bbbbiiiinnnndddd [----mmmm _k_e_y_m_a_p] _k_e_y_s_e_q:_f_u_n_c_t_i_o_n-_n_a_m_e Display current rrrreeeeaaaaddddlllliiiinnnneeee key and function bindings, or bind a key sequence to a rrrreeeeaaaaddddlllliiiinnnneeee function or macro. The binding syntax accepted is identical to that of ._i_n_p_u_t_r_c, but each binding must be passed as a separate argument; e.g., '"\C-x\C-r": re-read-init-file'. Options, if supplied, have the following meanings: ----mmmm _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. ----llll List the names of all rrrreeeeaaaaddddlllliiiinnnneeee functions ----vvvv List current function names and bindings ----dddd Dump function names and bindings in such a way that they can be re-read ----ffff _f_i_l_e_n_a_m_e Read key bindings from _f_i_l_e_n_a_m_e ----qqqq _f_u_n_c_t_i_o_n Query about which keys invoke the named _f_u_n_c_t_i_o_n The return value is 0 unless an unrecognized option is given or an error occurred. bbbbrrrreeeeaaaakkkk [_n] Exit from within a ffffoooorrrr, wwwwhhhhiiiilllleeee, or uuuunnnnttttiiiillll 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 the shell is not executing a loop when bbbbrrrreeeeaaaakkkk is executed. bbbbuuuuiiiillllttttiiiinnnn _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 you wish to define a function whose name is the same as a shell builtin, but need the functionality of the builtin within the function itself. The ccccdddd 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. ccccdddd [_d_i_r] Change the current directory to _d_i_r. The variable HHHHOOOOMMMMEEEE is the default _d_i_r. The variable CCCCDDDDPPPPAAAATTTTHHHH defines the search path for the directory containing _d_i_r. Alternative directory names are separated by a colon (:). A null directory name in CCCCDDDDPPPPAAAATTTTHHHH is the same as the current directory, i.e., ``....''. If _d_i_r begins with Page 42 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) a slash (/), then CCCCDDDDPPPPAAAATTTTHHHH is not used. An argument of ---- is equivalent to $$$$OOOOLLLLDDDDPPPPWWWWDDDD. The return value is true if the directory was successfully changed; false otherwise. ccccoooommmmmmmmaaaannnndddd [----ppppVVVVvvvv] _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 PPPPAAAATTTTHHHH are executed. If the ----pppp option is given, the search for _c_o_m_m_a_n_d is performed using a default value for PPPPAAAATTTTHHHH that is guaranteed to find all of the standard utilities. If either the ----VVVV or ----vvvv option is supplied, a description of _c_o_m_m_a_n_d is printed. The ----vvvv option causes a single word indicating the command or pathname used to invoke _c_o_m_m_a_n_d to be printed; the ----VVVV option produces a more verbose description. An argument of -------- disables option checking for the rest of the arguments. If the ----VVVV or ----vvvv 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 cannot be found, the exit status is 127. Otherwise, the exit status of the ccccoooommmmmmmmaaaannnndddd builtin is the exit status of _c_o_m_m_a_n_d. ccccoooonnnnttttiiiinnnnuuuueeee [_n] Resume the next iteration of the enclosing ffffoooorrrr, wwwwhhhhiiiilllleeee, or uuuunnnnttttiiiillll 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 the shell is not executing a loop when ccccoooonnnnttttiiiinnnnuuuueeee is executed. ddddeeeeccccllllaaaarrrreeee [----ffffrrrrxxxxiiii] [_n_a_m_e[=_v_a_l_u_e]] ttttyyyyppppeeeesssseeeetttt [----ffffrrrrxxxxiiii] [_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 instead. The options can be used to restrict output to variables with the specified attribute. ----ffff Use function names only ----rrrr Make _n_a_m_es readonly. These names cannot then be assigned values by subsequent assignment statements. ----xxxx Mark _n_a_m_es for export to subsequent commands via the environment. ----iiii The variable is treated as an integer; arithmetic evaluation (see AAAARRRRIIIITTTTHHHHMMMMEEEETTTTIIIICCCC EEEEVVVVAAAALLLLUUUUAAAATTTTIIIIOOOONNNN )))) is performed when the variable is assigned a value. Using `+' instead of `-' turns off the attribute instead. When used in a function, makes _n_a_m_es local, as with the llllooooccccaaaallll command. The return value is 0 Page 43 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) unless an illegal option is encountered, an attempt is made to define a function using "-f foo=bar", one of the _n_a_m_e_s is not a legal shell variable name, an attempt is made to turn off readonly status for a readonly variable, or an attempt is made to display a non-existant function with -f. ddddiiiirrrrssss [[[[----llll]]]] [[[[++++////----nnnn]]]] Display the list of currently remembered directories. Directories are added to the list with the ppppuuuusssshhhhdddd command; the ppppooooppppdddd command moves back up through the list. ++++nnnn displays the _nth entry counting from the left of the list shown by ddddiiiirrrrssss when invoked without options, starting with zero. ----nnnn displays the _nth entry counting from the right of the list shown by ddddiiiirrrrssss when invoked without options, starting with zero. ----llll produces a longer listing; the default listing format uses a tilde to denote the home directory. The return value is 0 unless an illegal option is supplied or _n indexes beyond the end of the directory stack. eeeecccchhhhoooo [----nnnneeeeEEEE] [_a_r_g ...] Output the _a_r_gs, separated by spaces. The return status is always 0. If ----nnnn is specified, the trailing newline is suppressed. If the ----eeee option is given, interpretation of the following backslash-escaped characters is enabled. The ----EEEE option disables the interpretation of these escape characters, even on systems where they are interpreted by default. \\\\aaaa alert (bell) \\\\bbbb backspace \\\\cccc suppress trailing newline \\\\ffff form feed \\\\nnnn new line \\\\rrrr carriage return \\\\tttt horizontal tab \\\\vvvv vertical tab \\\\\\\\ backslash \\\\nnnnnnnnnnnn the character whose ASCII code is _n_n_n (octal) eeeennnnaaaabbbblllleeee [----nnnn] [----aaaallllllll] [_n_a_m_e ...] Enable and disable builtin shell commands. This allows the execution of a disk command which has the same name as a shell builtin without specifying a full pathname. If ----nnnn is used, each _n_a_m_e is disabled; otherwise, _n_a_m_e_s are enabled. For example, to use the tttteeeesssstttt binary found via the PPPPAAAATTTTHHHH instead of the shell builtin version, type ``enable -n test''. If no arguments are given, a list Page 44 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) of all enabled shell builtins is printed. If only ----nnnn is supplied, a list of all disabled builtins is printed. If only ----aaaallllllll is supplied, the list printed includes all builtins, with an indication of whether or not each is enabled. eeeennnnaaaabbbblllleeee accepts ----aaaa as a synonym for ----aaaallllllll. The return value is 0 unless a _n_a_m_e is not a shell builtin. eeeevvvvaaaallll [_a_r_g ...] The _a_r_gs are read and concatenated together into a single command. This command is then read and executed by the shell, and its exit status is returned as the value of the eeeevvvvaaaallll command. If there are no _a_r_g_s, or only null arguments, eeeevvvvaaaallll returns true. eeeexxxxeeeecccc [[----] _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 first argument is ----, the shell places a dash in the zeroth arg passed to _c_o_m_m_a_n_d. This is what login does. If the file cannot be executed for some reason, a non-interactive shell exits, unless the shell variable nnnnoooo____eeeexxxxiiiitttt____oooonnnn____ffffaaaaiiiilllleeeedddd____eeeexxxxeeeecccc exists, 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 redirections take effect in the current shell, and the return status is 0. eeeexxxxiiiitttt [_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 EEEEXXXXIIIITTTT is executed before the shell terminates. eeeexxxxppppoooorrrrtttt [----nnnnffff] [_n_a_m_e[=_w_o_r_d]] ... eeeexxxxppppoooorrrrtttt ----pppp The supplied _n_a_m_e_s are marked for automatic export to the environment of subsequently executed commands. If the ----ffff option is given, the _n_a_m_e_s refer to functions. If no _n_a_m_e_s are given, or if the ----pppp option is supplied, a list of all names that are exported in this shell is printed. The ----nnnn option causes the export property to be removed from the named variables. An argument of -------- disables option checking for the rest of the arguments. eeeexxxxppppoooorrrrtttt returns an exit status of 0 unless an illegal option is encountered, one of the _n_a_m_e_s is not a legal shell variable name, or ----ffff is supplied with a _n_a_m_e that is not a function. ffffcccc [----eeee _e_n_a_m_e] [----nnnnllllrrrr] [_f_i_r_s_t] [_l_a_s_t] ffffcccc ----ssss [_p_a_t=_r_e_p] [_c_m_d] Page 45 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) 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 current command number). If _l_a_s_t is not specified it is set to the current command for listing (so that ffffcccc ----llll ----11110000 prints the last 10 commands) and to _f_i_r_s_t otherwise. If _f_i_r_s_t is not specified it is set to the previous command for editing and -16 for listing. The ----nnnn flag suppresses the command numbers when listing. The ----rrrr flag reverses the order of the commands. If the ----llll flag is given, the commands are listed on standard output. Otherwise, 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 FFFFCCCCEEEEDDDDIIIITTTT variable is used, and the value of EEEEDDDDIIIITTTTOOOORRRR if FFFFCCCCEEEEDDDDIIIITTTT is not set. If neither variable is set, _v_i 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 command. If the first form is used, the return value is 0 unless an illegal option is encountered or _f_i_r_s_t or _l_a_s_t specify history lines out of range. If the ----eeee 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- executed, unless _c_m_d does not specify a valid history line, in which case ffffcccc returns failure. ffffgggg [_j_o_b_s_p_e_c] Place _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 specify a valid job or _j_o_b_s_p_e_c specifies a job that was started without job control. ggggeeeettttooooppppttttssss _o_p_t_s_t_r_i_n_g _n_a_m_e [_a_r_g_s] ggggeeeettttooooppppttttssss is used by shell procedures to parse positional parameters. _o_p_t_s_t_r_i_n_g contains the option letters to Page 46 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) be recognized; if a letter is followed by a colon, the option is expected to have an argument, which should be separated from it by white space. Each time it is invoked, ggggeeeettttooooppppttttssss 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 OOOOPPPPTTTTIIIINNNNDDDD. OOOOPPPPTTTTIIIINNNNDDDD is initialized to 1 each time the shell or a shell script is invoked. When an option requires an argument, ggggeeeettttooooppppttttssss places that argument into the variable OOOOPPPPTTTTAAAARRRRGGGG. The shell does not reset OOOOPPPPTTTTIIIINNNNDDDD automatically; it must be manually reset between multiple calls to ggggeeeettttooooppppttttssss within the same shell invocation if a new set of parameters is to be used. ggggeeeettttooooppppttttssss 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 illegal options or missing option arguments are encountered. If the variable OOOOPPPPTTTTEEEERRRRRRRR is set to 0, no error message will be displayed, even if the first character of _o_p_t_s_t_r_i_n_g is not a colon. If an illegal option is seen, ggggeeeettttooooppppttttssss places ? into _n_a_m_e and, if not silent, prints an error message and unsets OOOOPPPPTTTTAAAARRRRGGGG. If ggggeeeettttooooppppttttssss is silent, the option character found is placed in OOOOPPPPTTTTAAAARRRRGGGG and no diagnostic message is printed. If a required argument is not found, and ggggeeeettttooooppppttttssss is not silent, a question mark (????) is placed in _n_a_m_e, OOOOPPPPTTTTAAAARRRRGGGG is unset, and a diagnostic message is printed. If ggggeeeettttooooppppttttssss is silent, then a colon (::::) is placed in _n_a_m_e and OOOOPPPPTTTTAAAARRRRGGGG is set to the option character found. ggggeeeettttooooppppttttssss normally parses the positional parameters, but if more arguments are given in _a_r_g_s, ggggeeeettttooooppppttttssss parses those instead. ggggeeeettttooooppppttttssss returns true if an option, specified or unspecified, is found. It returns false if the end of options is encountered or an error occurs. hhhhaaaasssshhhh [----rrrr] [_n_a_m_e] For each _n_a_m_e, the full pathname of the command is determined and remembered. The ----rrrr option causes the shell to forget all remembered locations. If no arguments are given, information about remembered commands is printed. An argument of -------- disables option checking for the rest of the arguments. The return status is true unless a _n_a_m_e is not found or an illegal option is supplied. Page 47 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) hhhheeeellllpppp [_p_a_t_t_e_r_n] Display helpful information about builtin commands. If _p_a_t_t_e_r_n is specified, hhhheeeellllpppp gives detailed help on all commands matching _p_a_t_t_e_r_n; otherwise a list of the builtins is printed. The return status is 0 unless no command matches _p_a_t_t_e_r_n. hhhhiiiissssttttoooorrrryyyy [_n] hhhhiiiissssttttoooorrrryyyy ----rrrrwwwwaaaannnn [_f_i_l_e_n_a_m_e] With no options, display the command history list with line numbers. Lines listed with a **** have been modified. An argument of _n lists only the last _n lines. If a non-option argument is supplied, it is used as the name of the history file; if not, the value of HHHHIIIISSSSTTTTFFFFIIIILLLLEEEE is used. Options, if supplied, have the following meanings: ----aaaa Append the ``new'' history lines (history lines entered since the beginning of the current bbbbaaaasssshhhh session) to the history file ----nnnn 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 bbbbaaaasssshhhh session. ----rrrr Read the contents of the history file and use them as the current history ----wwww Write the current history to the history file, overwriting the history file's contents. The return value is 0 unless an illegal option is encountered or an error occurs while reading or writing the history file. jjjjoooobbbbssss [----llllnnnnpppp] [ _j_o_b_s_p_e_c ... ] jjjjoooobbbbssss ----xxxx _c_o_m_m_a_n_d [ _a_r_g_s ... ] The first form lists the active jobs. The ----llll option lists process IDs in addition to the normal information; the ----pppp option lists only the process ID of the job's process group leader. The ----nnnn option displays only jobs that have changed status since last notified. 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 illegal option is encountered or an illegal _j_o_b_s_p_e_c is supplied. If the ----xxxx option is supplied, jjjjoooobbbbssss 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. kkkkiiiillllllll [----ssss ssssiiiiggggssssppppeeeecccc | ----ssssiiiiggggssssppppeeeecccc] [_p_i_d | _j_o_b_s_p_e_c] ... kkkkiiiillllllll ----llll [_s_i_g_n_u_m] Send the signal named by _s_i_g_s_p_e_c to the processes named Page 48 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) by _p_i_d or _j_o_b_s_p_e_c. _s_i_g_s_p_e_c is either a signal name such as SSSSIIIIGGGGKKKKIIIILLLLLLLL or a signal number. If _s_i_g_s_p_e_c is a signal name, the name is case insensitive and may be given with or without the SSSSIIIIGGGG prefix. If _s_i_g_s_p_e_c is not present, then SSSSIIIIGGGGTTTTEEEERRRRMMMM is assumed. An argument of ----llll lists the signal names. If any arguments are supplied when ----llll is given, the names of the specified signals are listed, and the return status is 0. An argument of -------- disables option checking for the rest of the arguments. kkkkiiiillllllll returns true if at least one signal was successfully sent, or false if an error occurs or an illegal option is encountered. lllleeeetttt _a_r_g [_a_r_g ...] Each _a_r_g is an arithmetic expression to be evaluated (see AAAARRRRIIIITTTTHHHHMMMMEEEETTTTIIIICCCC EEEEVVVVAAAALLLLUUUUAAAATTTTIIIIOOOONNNN). If the last _a_r_g evaluates to 0, lllleeeetttt returns 1; 0 is returned otherwise. llllooooccccaaaallll [_n_a_m_e[=_v_a_l_u_e] ...] For each argument, create a local variable named _n_a_m_e, and assign it _v_a_l_u_e. When llllooooccccaaaallll is used within a function, it causes the variable _n_a_m_e to have a visible scope restricted to that function and its children. With no operands, llllooooccccaaaallll writes a list of local variables to the standard output. It is an error to use llllooooccccaaaallll when not within a function. The return status is 0 unless llllooooccccaaaallll is used outside a function, or an illegal _n_a_m_e is supplied. llllooooggggoooouuuutttt Exit a login shell. ppppooooppppdddd [++++////----nnnn] Removes entries from the directory stack. With no arguments, removes the top directory from the stack, and performs a ccccdddd to the new top directory. ++++nnnn removes the _nth entry counting from the left of the list shown by ddddiiiirrrrssss, starting with zero. For example: ``popd +0'' removes the first directory, ``popd +1'' the second. ----nnnn removes the _nth entry counting from the right of the list shown by ddddiiiirrrrssss, starting with zero. For example: ``popd -0'' removes the last directory, ``popd -1'' the next to last. If the ppppooooppppdddd command is successful, a ddddiiiirrrrssss is performed as well, and the return status is 0. ppppooooppppdddd returns false if an illegal option is encountered, the directory stack is empty, a non-existent directory stack entry is specified, or the directory change fails. Page 49 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) ppppuuuusssshhhhdddd [_d_i_r] ppppuuuusssshhhhdddd ++++////----nnnn 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. ++++nnnn Rotates the stack so that the _nth directory (counting from the left of the list shown by ddddiiiirrrrssss) is at the top. ----nnnn Rotates the stack so that the _nth directory (counting from the right) is at the top. ddddiiiirrrr adds _d_i_r to the directory stack at the top, making it the new current working directory. If the ppppuuuusssshhhhdddd command is successful, a ddddiiiirrrrssss is performed as well. If the first form is used, ppppuuuusssshhhhdddd returns 0 unless the cd to _d_i_r fails. With the second form, ppppuuuusssshhhhdddd returns 0 unless the directory stack is empty, a non-existant directory stack element is specified, or the directory change to the specified new current directory fails. ppppwwwwdddd Print the absolute pathname of the current working directory. The path printed contains no symbolic links if the ----PPPP option to the sssseeeetttt builtin command is set. See also the description of nnnnoooolllliiiinnnnkkkkssss under SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss above). The return status is 0 unless an error occurs while reading the pathname of the current directory. rrrreeeeaaaadddd [----rrrr] [_n_a_m_e ...] One line is read from the standard input, 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 assigned to the last _n_a_m_e. Only the characters in IIIIFFFFSSSS are recognized as word delimiters. If no _n_a_m_e_s are supplied, the line read is assigned to the variable RRRREEEEPPPPLLLLYYYY. The return code is zero, unless end-of-file is encountered. If the ----rrrr option is given, a backslash- newline pair is not ignored, and the backslash is considered to be part of the line. rrrreeeeaaaaddddoooonnnnllllyyyy [----ffff] [_n_a_m_e ...] rrrreeeeaaaaddddoooonnnnllllyyyy ----pppp The given _n_a_m_e_s are marked readonly and the values of these _n_a_m_e_s may not be changed by subsequent assignment. If the ----ffff option is supplied, the functions corresponding to the _n_a_m_e_s are so marked. If no arguments are given, or if the ----pppp option is supplied, a list of all readonly names is printed. An argument of -------- disables option checking for the rest of Page 50 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) the arguments. The return status is 0 unless an illegal option is encountered, one of the _n_a_m_e_s is not a legal shell variable name, or ----ffff is supplied with a _n_a_m_e that is not a function. rrrreeeettttuuuurrrrnnnn [_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 .... (ssssoooouuuurrrrcccceeee) 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. sssseeeetttt [--------aaaabbbbeeeeffffhhhhkkkkmmmmnnnnppppttttuuuuvvvvxxxxllllddddCCCCHHHHPPPP] [----oooo _o_p_t_i_o_n] [_a_r_g ...] ----aaaa Automatically mark variables which are modified or created for export to the environment of subsequent commands. ----bbbb Cause the status of terminated background jobs to be reported immediately, rather than before the next primary prompt. (Also see nnnnoooottttiiiiffffyyyy under SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss above). ----eeee Exit immediately if a _s_i_m_p_l_e-_c_o_m_m_a_n_d (see SSSSHHHHEEEELLLLLLLL GGGGRRRRAAAAMMMMMMMMAAAARRRR above) exits with a non-zero status. The shell does not exit if the command that fails is part of an _u_n_t_i_l or _w_h_i_l_e loop, part of an _i_f statement, part of a &&&&&&&& or |||||||| list, or if the command's return value is being inverted via !!!!. ----ffff Disable pathname expansion. ----hhhh Locate and remember function commands as functions are defined. Function commands are normally looked up when the function is executed. ----kkkk All keyword arguments are placed in the environment for a command, not just those that precede the command name. ----mmmm Monitor mode. Job control is enabled. This flag is on by default for interactive shells on systems that support it (see JJJJOOOOBBBB CCCCOOOONNNNTTTTRRRROOOOLLLL above). Background processes run in a separate process group and a line containing their exit status is printed upon their completion. ----nnnn Read commands but do not execute them. This may be used to check a shell script for syntax errors. This is ignored for interactive shells. ----oooo _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: Page 51 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) aaaalllllllleeeexxxxppppoooorrrrtttt Same as ----aaaa. bbbbrrrraaaacccceeeeeeeexxxxppppaaaannnndddd The shell performs brace expansion (see BBBBrrrraaaacccceeee EEEExxxxppppaaaannnnssssiiiioooonnnn above). This is on by default. eeeemmmmaaaaccccssss Use an emacs-style command line editing interface. This is enabled by default when the shell is interactive, unless the shell is started with the ----nnnnoooolllliiiinnnneeeeeeeeddddiiiittttiiiinnnngggg option. eeeerrrrrrrreeeexxxxiiiitttt Same as ----eeee. hhhhiiiisssstttteeeexxxxppppaaaannnndddd Same as ----HHHH. iiiiggggnnnnoooorrrreeeeeeeeooooffff The effect is as if the shell command `IGNOREEOF=10' had been executed (see SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss above). iiiinnnntttteeeerrrraaaaccccttttiiiivvvveeee----ccccoooommmmmmmmeeeennnnttttssss Allow a word beginning with #### to cause that word and all remaining characters on that line to be ignored in an interactive shell (see CCCCOOOOMMMMMMMMEEEENNNNTTTTSSSS above). mmmmoooonnnniiiittttoooorrrr Same as ----mmmm. nnnnoooocccclllloooobbbbbbbbeeeerrrr Same as ----CCCC. nnnnooooeeeexxxxeeeecccc Same as ----nnnn. nnnnoooogggglllloooobbbb Same as ----ffff. nnnnoooohhhhaaaasssshhhh Same as ----dddd. nnnnoooottttiiiiffffyyyy Same as ----bbbb. nnnnoooouuuunnnnsssseeeetttt Same as ----uuuu. pppphhhhyyyyssssiiiiccccaaaallll Same as ----PPPP. ppppoooossssiiiixxxx Change the behavior of bash where the default operation differs from the Posix 1003.2 standard to match the standard. pppprrrriiiivvvviiiilllleeeeggggeeeedddd Same as ----pppp. vvvveeeerrrrbbbboooosssseeee Same as ----vvvv. vvvviiii Use a vi-style command line editing interface. xxxxttttrrrraaaacccceeee Same as ----xxxx. If no _o_p_t_i_o_n-_n_a_m_e is supplied, the values of the current options are printed. ----pppp Turn on _p_r_i_v_i_l_e_g_e_d mode. In this mode, the $$$$EEEENNNNVVVV file is not processed, and shell functions are not inherited from the environment. This is enabled automatically on startup if the effective user (group) id is not equal to the real user (group) id. Turning this option off causes the effective user and group ids to be Page 52 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) set to the real user and group ids. ----tttt Exit after reading and executing one command. ----uuuu Treat unset variables as an error when performing parameter expansion. If expansion is attempted on an unset variable, the shell prints an error message, and, if not interactive, exits with a non-zero status. ----vvvv Print shell input lines as they are read. ----xxxx After expanding each _s_i_m_p_l_e-_c_o_m_m_a_n_d, bbbbaaaasssshhhh displays the expanded value of PPPPSSSS4444, followed by the command and its expanded arguments. ----llll Save and restore the binding of _n_a_m_e in a ffffoooorrrr _n_a_m_e [in wwwwoooorrrrdddd] command (see SSSSHHHHEEEELLLLLLLL GGGGRRRRAAAAMMMMMMMMAAAARRRR above). ----dddd Disable the hashing of commands that are looked up for execution. Normally, commands are remembered in a hash table, and once found, do not have to be looked up again. ----CCCC The effect is as if the shell command `noclobber=' had been executed (see SSSShhhheeeellllllll VVVVaaaarrrriiiiaaaabbbblllleeeessss above). ----HHHH Enable !!!! style history substitution. This flag is on by default when the shell is interactive. ----PPPP If set, do not follow symbolic links when performing commands such as ccccdddd which change the current directory. The physical directory is used instead. -------- If no arguments follow this flag, then the positional parameters are unset. Otherwise, the positional parameters 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 ----xxxx and ----vvvv options are turned off. If there are no _a_r_gs, the positional parameters remain unchanged. The flags are off by default unless otherwise noted. Using + rather than - causes these flags to be turned off. The flags can also be specified as options to an invocation of the shell. The current set of flags may be found in $$$$----. After the option arguments are processed, the remaining _n _a_r_gs are treated as values for the positional parameters and are assigned, in order, to $$$$1111, $$$$2222, ............ $$$$_n. If no options or _a_r_gs are supplied, all shell variables are printed. The return status is always true unless an illegal option is encountered. sssshhhhiiiifffftttt [_n] The positional parameters from _n+1 ... are renamed to $$$$1111 ................ Parameters represented by the numbers $$$$#### down Page 53 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) to $$$$####-_n+1 are unset. If _n is 0, no parameters are changed. If _n is not given, it is assumed to be 1. _n must be a non-negative number less than or equal to $$$$####. If _n is greater than $$$$####, the positional parameters are not changed. The return status is greater than 0 if _n is greater than $$$$#### or less than 0; otherwise 0. ssssuuuussssppppeeeennnndddd [----ffff] Suspend the execution of this shell until it receives a SSSSIIIIGGGGCCCCOOOONNNNTTTT signal. The ----ffff option says not to complain if this is a login shell; just suspend anyway. The return status is 0 unless the shell is a login shell and ----ffff is not supplied, or if job control is not enabled. tttteeeesssstttt _e_x_p_r [[[[ _e_x_p_r ]]]] Return a status of 0 (true) or 1 (false) depending on the evaluation of the conditional expression _e_x_p_r. Expressions may be unary or binary. Unary expressions are often used to examine the status of a file. There are string operators and numeric comparison operators as well. Each operator and operand must be a separate argument. If _f_i_l_e is of the form /dev/fd/_n, then file descriptor _n is checked. ----bbbb _f_i_l_e True if _f_i_l_e exists and is block special. ----cccc _f_i_l_e True if _f_i_l_e exists and is character special. ----dddd _f_i_l_e True if _f_i_l_e exists and is a directory. ----eeee _f_i_l_e True if _f_i_l_e exists. ----ffff _f_i_l_e True if _f_i_l_e exists and is a regular file. ----gggg _f_i_l_e True if _f_i_l_e exists and is set-group-id. ----kkkk _f_i_l_e True if _f_i_l_e has its ``sticky'' bit set. ----LLLL _f_i_l_e True if _f_i_l_e exists and is a symbolic link. ----pppp _f_i_l_e True if _f_i_l_e exists and is a named pipe. ----rrrr _f_i_l_e True if _f_i_l_e exists and is readable. ----ssss _f_i_l_e True if _f_i_l_e exists and has a size greater than zero. ----SSSS _f_i_l_e True if _f_i_l_e exists and is a socket. ----tttt _f_d True if _f_d is opened on a terminal. ----uuuu _f_i_l_e Page 54 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) True if _f_i_l_e exists and its set-user-id bit is set. ----wwww _f_i_l_e True if _f_i_l_e exists and is writable. ----xxxx _f_i_l_e True if _f_i_l_e exists and is executable. ----OOOO _f_i_l_e True if _f_i_l_e exists and is owned by the effective user id. ----GGGG _f_i_l_e True if _f_i_l_e exists and is owned by the effective group id. _f_i_l_e_1 -nnnntttt _f_i_l_e_2 True if _f_i_l_e_1 is newer (according to modification date) than _f_i_l_e_2. _f_i_l_e_1 -ooootttt _f_i_l_e_2 True if _f_i_l_e_1 is older than file2. _f_i_l_e_1 ----eeeeffff _f_i_l_e True if _f_i_l_e_1 and _f_i_l_e_2 have the same device and inode numbers. ----zzzz _s_t_r_i_n_g True if the length of _s_t_r_i_n_g is zero. ----nnnn _s_t_r_i_n_g _s_t_r_i_n_g True if the length of _s_t_r_i_n_g is non-zero. _s_t_r_i_n_g_1 ==== _s_t_r_i_n_g_2 True if the strings are equal. _s_t_r_i_n_g_1 !!!!==== _s_t_r_i_n_g_2 True if the strings are not equal. !!!! _e_x_p_r True if _e_x_p_r is false. _e_x_p_r_1 -aaaa _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 -oooo _e_x_p_r_2 True if either _e_x_p_r_1 OR _e_x_p_r_2 is true. _a_r_g_1 OOOOPPPP _a_r_g_2 OOOOPPPP is one of ----eeeeqqqq, ----nnnneeee, ----lllltttt, ----lllleeee, ----ggggtttt, or ----ggggeeee. These arithmetic binary operators return true if _a_r_g_1 is equal, not-equal, less-than, less-than- or-equal, greater-than, or greater-than-or-equal than _a_r_g_2, respectively. _A_r_g_1 and _a_r_g_2 may be positive integers, negative integers, or the special expression ----llll _s_t_r_i_n_g, which evaluates to the length of _s_t_r_i_n_g. ttttiiiimmmmeeeessss Print the accumulated user and system times for the shell and for processes run from the shell. The return status is 0. ttttrrrraaaapppp [----llll] [_a_r_g] [_s_i_g_s_p_e_c] The command _a_r_g is to be read and executed when the Page 55 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) shell receives signal(s) _s_i_g_s_p_e_c. If _a_r_g is absent or ----, all specified signals are reset to their original values (the values they had upon entrance to the shell). If _a_r_g is the null string this signal is ignored by the shell and by the commands it invokes. _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. If _s_i_g_s_p_e_c is EEEEXXXXIIIITTTT (0) the command _a_r_g is executed on exit from the shell. With no arguments, ttttrrrraaaapppp prints the list of commands associated with each signal number. The ----llll option causes the shell to print a list of signal names and their corresponding numbers. An argument of -------- disables option checking for the rest of the arguments. Signals ignored upon entry to the shell cannot be trapped or reset. Trapped signals are reset to their original values in a child process when it is created. The return status is false if either the trap name or number is invalid; otherwise ttttrrrraaaapppp returns true. ttttyyyyppppeeee [----aaaallllllll] [----ttttyyyyppppeeee | ----ppppaaaatttthhhh] _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 ----ttttyyyyppppeeee flag is used, ttttyyyyppppeeee prints a phrase 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 name is not found, then nothing is printed, and an exit status of false is returned. If the ----ppppaaaatttthhhh flag is used, ttttyyyyppppeeee either returns the name of the disk file that would be executed if _n_a_m_e were specified as a command name, or nothing if ----ttttyyyyppppeeee would not return _f_i_l_e. If a command is hashed, ----ppppaaaatttthhhh prints the hashed value, not necessarily the file that appears first in PPPPAAAATTTTHHHH. If the ----aaaallllllll flag is used, ttttyyyyppppeeee prints all of the places that contain an executable named _n_a_m_e. This includes aliases and functions, if and only if the ----ppppaaaatttthhhh flag is not also used. The table of hashed commands is not consulted when using ----aaaallllllll. ttttyyyyppppeeee accepts ----aaaa, ----tttt, and ----pppp in place of ----aaaallllllll, ----ttttyyyyppppeeee, and ----ppppaaaatttthhhh, respectively. An argument of -------- disables option checking for the rest of the arguments. ttttyyyyppppeeee returns true if any of the arguments are found, false if none are found. uuuulllliiiimmmmiiiitttt [----SSSSHHHHaaaaccccddddffffmmmmssssttttppppnnnnuuuuvvvv [_l_i_m_i_t]] UUUUlllliiiimmmmiiiitttt provides control over the resources available to the shell and to processes started by it, on systems that allow such control. The value of _l_i_m_i_t can be a number in the unit specified for the resource, or the value uuuunnnnlllliiiimmmmiiiitttteeeedddd. The HHHH and SSSS options specify that the hard or soft limit is set for the given resource. A hard limit cannot be increased once it is set; a soft limit may be increased up to the value of the hard Page 56 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) limit. If neither HHHH nor SSSS is specified, the command applies to the soft limit. If _l_i_m_i_t is omitted, the current value of the soft limit of the resource is printed, unless the HHHH option is given. When more than one resource is specified, the limit name and unit is printed before the value. Other options are interpreted as follows: ----aaaa all current limits are reported ----cccc the maximum size of core files created ----dddd the maximum size of a process's data segment ----ffff the maximum size of files created by the shell ----mmmm the maximum resident set size ----ssss the maximum stack size ----tttt the maximum amount of cpu time in seconds ----pppp the pipe size in 512-byte blocks (this may not be set) ----nnnn the maximum number of open file descriptors (most systems do not allow this value to be set, only displayed) ----uuuu the maximum number of processes available to a single user ----vvvv The maximum amount of virtual memory available to the shell An argument of -------- disables option checking for the rest of the arguments. If _l_i_m_i_t is given, it is the new value of the specified resource (the ----aaaa option is display only). If no option is given, then ----ffff is assumed. Values are in 1024-byte increments, except for ----tttt, which is in seconds, ----pppp, which is in units of 512-byte blocks, and ----nnnn and ----uuuu, which are unscaled values. The return status is 0 unless an illegal option is encountered, a non-numeric argument other than uuuunnnnlllliiiimmmmiiiitttteeeedddd is supplied as _l_i_m_i_t, or an error occurs while setting a new limit. uuuummmmaaaasssskkkk [----SSSS] [_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, or if the ----SSSS option is supplied, the current value of the mask is printed. The ----SSSS option causes the mask to be printed in symbolic form; the default output is an octal number. An argument of -------- disables option checking for the rest of the arguments. The return status is 0 if the mode was successfully changed or if no _m_o_d_e argument was supplied, and false otherwise. uuuunnnnaaaalllliiiiaaaassss [-aaaa] [_n_a_m_e ...] Remove _n_a_m_es from the list of defined aliases. If ----aaaa is supplied, all alias definitions are removed. The Page 57 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) return value is true unless a supplied _n_a_m_e is not a defined alias. uuuunnnnsssseeeetttt [-ffffvvvv] [_n_a_m_e ...] For each _n_a_m_e, remove the corresponding variable or, given the ----ffff option, function. An argument of -------- disables option checking for the rest of the arguments. Note that PPPPAAAATTTTHHHH, IIIIFFFFSSSS, PPPPPPPPIIIIDDDD, PPPPSSSS1111, PPPPSSSS2222, UUUUIIIIDDDD, and EEEEUUUUIIIIDDDD cannot be unset. If any of RRRRAAAANNNNDDDDOOOOMMMM, SSSSEEEECCCCOOOONNNNDDDDSSSS, LLLLIIIINNNNEEEENNNNOOOO, or HHHHIIIISSSSTTTTCCCCMMMMDDDD are unset, they lose their special properties, even if they are subsequently reset. The exit status is true unless a _n_a_m_e does not exist or is non- unsettable. wwwwaaaaiiiitttt [_n] Wait for the specified process and return its termination status. _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 processes are waited for, and the return status is zero. If _n specifies a non- existant process or job, the return status is 127. Otherwise, the return status is the exit status of the last process or job waited for. IIIINNNNVVVVOOOOCCCCAAAATTTTIIIIOOOONNNN A _l_o_g_i_n _s_h_e_l_l is one whose first character of argument zero is a ----, or one started with the ----llllooooggggiiiinnnn flag. An _i_n_t_e_r_a_c_t_i_v_e shell is one whose standard input and output are both connected to terminals (as determined by _i_s_a_t_t_y(3)), or one started with the ----iiii option. PPPPSSSS1111 is set and $$$$---- includes iiii if bbbbaaaasssshhhh is interactive, allowing a shell script or a startup file to test this state. Login shells: On login (subject to the ----nnnnoooopppprrrrooooffffiiiilllleeee option): if /_e_t_c/_p_r_o_f_i_l_e exists, source it. if ~/._b_a_s_h__p_r_o_f_i_l_e exists, source it, else if ~/._b_a_s_h__l_o_g_i_n exists, source it, else if ~/._p_r_o_f_i_l_e exists, source it. On exit: if ~/._b_a_s_h__l_o_g_o_u_t exists, source it. Non-login interactive shells: On startup (subject to the ----nnnnoooorrrrcccc and ----rrrrccccffffiiiilllleeee options): if ~/._b_a_s_h_r_c exists, source it. Non-interactive shells: On startup: Page 58 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) if the environment variable EEEENNNNVVVV is non-null, expand it and source the file it names, as if the command if [ "$ENV" ]; then . $ENV; fi had been executed, but do not use PPPPAAAATTTTHHHH to search for the pathname. When not started in Posix mode, bash looks for BBBBAAAASSSSHHHH____EEEENNNNVVVV before EEEENNNNVVVV. If Bash is invoked as sssshhhh, it tries to mimic the behavior of sssshhhh as closely as possible. For a login shell, it attempts to source only /_e_t_c/_p_r_o_f_i_l_e and ~/._p_r_o_f_i_l_e, in that order. The ----nnnnoooopppprrrrooooffffiiiilllleeee option may still be used to disable this behavior. A shell invoked as sssshhhh does not attempt to source any other startup files. When bbbbaaaasssshhhh is started in _p_o_s_i_x mode, as with the ----ppppoooossssiiiixxxx command line option, it follows the Posix standard for startup files. In this mode, the EEEENNNNVVVV variable is expanded and that file sourced; no other startup files are read. SSSSEEEEEEEE AAAALLLLSSSSOOOO _B_a_s_h _F_e_a_t_u_r_e_s, Brian Fox and Chet Ramey _T_h_e _G_n_u _R_e_a_d_l_i_n_e _L_i_b_r_a_r_y, Brian Fox and Chet Ramey _T_h_e _G_n_u _H_i_s_t_o_r_y _L_i_b_r_a_r_y, Brian Fox and Chet Ramey Lennert _A _S_y_s_t_e_m _V _C_o_m_p_a_t_i_b_l_e _I_m_p_l_e_m_e_n_t_a_t_i_o_n _o_f _4._2_B_S_D _J_o_b _C_o_n_t_r_o_l, David _U_t_i_l_i_t_i_e_s, IEEE _P_o_r_t_a_b_l_e _O_p_e_r_a_t_i_n_g _S_y_s_t_e_m _I_n_t_e_r_f_a_c_e (_P_O_S_I_X) _P_a_r_t _2: _S_h_e_l_l _a_n_d _s_h(1), _k_s_h(1), _c_s_h(1) _e_m_a_c_s(1), _v_i(1) _r_e_a_d_l_i_n_e(3) FFFFIIIILLLLEEEESSSS /_b_i_n/_b_a_s_h The bbbbaaaasssshhhh executable /_e_t_c/_p_r_o_f_i_l_e The systemwide initialization file, executed for login shells ~/._b_a_s_h__p_r_o_f_i_l_e The personal initialization file, executed for login shells ~/._b_a_s_h_r_c The individual per-interactive-shell startup file ~/._i_n_p_u_t_r_c Individual _r_e_a_d_l_i_n_e initialization file AAAAUUUUTTTTHHHHOOOORRRRSSSS Brian Fox, Free Software Foundation (primary author) bfox@ai.MIT.Edu Chet Ramey, Case Western Reserve University chet@ins.CWRU.Edu Page 59 (printed 7/6/95) BBBBAAAASSSSHHHH((((1111)))) GGGGNNNNUUUU ((((1111999999995555 MMMMaaaarrrr 9999)))) BBBBAAAASSSSHHHH((((1111)))) BBBBUUUUGGGG RRRREEEEPPPPOOOORRRRTTTTSSSS If you find a bug in bbbbaaaasssshhhh,,,, you should report it. But first, you should make sure that it really is a bug, and that it appears in the latest version of bbbbaaaasssshhhh that you have. Once you have determined that a bug actually exists, mail a bug report to _b_a_s_h-_m_a_i_n_t_a_i_n_e_r_s@_p_r_e_p._a_i._M_I_T._E_d_u. If you have a fix, you are welcome to mail that as well! Suggestions and `philosophical' bug reports may be mailed to _b_u_g- _b_a_s_h@_p_r_e_p._a_i._M_I_T._E_d_u or posted to the Usenet newsgroup ggggnnnnuuuu....bbbbaaaasssshhhh....bbbbuuuugggg. ALL bug reports should include: The version number of bbbbaaaasssshhhh The hardware and operating system The compiler used to compile A description of the bug behaviour A short script or `recipe' which exercises the bug Comments and bug reports concerning this manual page should be directed to _c_h_e_t@_i_n_s._C_W_R_U._E_d_u. BBBBUUUUGGGGSSSS It's too big and too slow. There are some subtle differences between bbbbaaaasssshhhh and traditional versions of sssshhhh, mostly because of the PPPPOOOOSSSSIIIIXXXX specification. Aliases are confusing in some uses. Page 60 (printed 7/6/95) 
