📄 builtins.0
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--pp, ddeeccllaarree will display the attributes and values of all shell variables. The --ff option will restrict the display to shell functions. The --FF option inhibits the display of function defi- nitions; only the function name and attributes are printed. If the eexxttddeebbuugg shell option is enabled using sshhoopptt, the source file name and line number where the function is defined are dis- played as well. The --FF option implies --ff. The --gg option forces variables to be created or modified at the global scope, even when ddeeccllaarree is executed in a shell function. It is ignored in all other cases. The following options can be used to restrict output to variables with the specified attribute or to give variables attributes: --aa Each _n_a_m_e is an indexed array variable (see AArrrraayyss above). --AA Each _n_a_m_e is an associative array variable (see AArrrraayyss above). --ff Use function names only. --ii The variable is treated as an integer; arithmetic evalua- tion (see AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN above) is performed when the variable is assigned a value. --ll When the variable is assigned a value, all upper-case characters are converted to lower-case. The upper-case attribute is disabled. --rr Make _n_a_m_es readonly. These names cannot then be assigned values by subsequent assignment statements or unset. --tt Give each _n_a_m_e the _t_r_a_c_e attribute. Traced functions inherit the DDEEBBUUGG and RREETTUURRNN traps from the calling shell. The trace attribute has no special meaning for variables. --uu When the variable is assigned a value, all lower-case characters are converted to upper-case. The lower-case attribute is disabled. --xx Mark _n_a_m_es for export to subsequent commands via the environment. Using `+' instead of `-' turns off the attribute instead, with the exceptions that ++aa may not be used to destroy an array vari- able and ++rr will not remove the readonly attribute. When used in a function, makes each _n_a_m_e local, as with the llooccaall command, unless the --ggPP ooppttiioonn iiss ssuupppplliieedd,, IIff aa vvaarriiaabbllee nnaammee iiss ffooll-- lloowweedd bbyy ==_v_a_l_u_e,, tthhee vvaalluuee ooff tthhee vvaarriiaabbllee iiss sseett ttoo _v_a_l_u_e.. TThhee rreettuurrnn vvaalluuee iiss 00 uunnlleessss aann iinnvvaalliidd ooppttiioonn iiss eennccoouunntteerreedd,, aann aatttteemmpptt iiss mmaaddee ttoo ddeeffiinnee aa ffuunnccttiioonn uussiinngg ````--ff ffoooo==bbaarr'''',, aann aatttteemmpptt iiss mmaaddee ttoo aassssiiggnn aa vvaalluuee ttoo aa rreeaaddoonnllyy vvaarriiaabbllee,, aann aatttteemmpptt iiss mmaaddee ttoo aassssiiggnn aa vvaalluuee ttoo aann aarrrraayy vvaarriiaabbllee wwiitthhoouutt uussiinngg tthhee ccoommppoouunndd aassssiiggnnmmeenntt ssyynnttaaxx ((sseeee AArrrraayyss above), one of the _n_a_m_e_s is not a valid shell variable name, an attempt is made to turn off readonly status for a readonly variable, an attempt is made to turn off array status for an array variable, or an attempt is made to display a non-existent function with --ff. ddiirrss [[++_n]] [[--_n]] [[--ccllppvv]] Without options, displays the list of currently remembered directories. The default display is on a single line with directory names separated by spaces. Directories are added to the list with the ppuusshhdd command; the ppooppdd command removes entries from the list. ++_n Displays the _nth entry counting from the left of the list shown by ddiirrss when invoked without options, starting with zero. --_n Displays the _nth entry counting from the right of the list shown by ddiirrss when invoked without options, starting with zero. --cc Clears the directory stack by deleting all of the entries. --ll Produces a longer listing; the default listing format uses a tilde to denote the home directory. --pp Print the directory stack with one entry per line. --vv Print the directory stack with one entry per line, pre- fixing each entry with its index in the stack. The return value is 0 unless an invalid option is supplied or _n indexes beyond the end of the directory stack. ddiissoowwnn [--aarr] [--hh] [_j_o_b_s_p_e_c ...] Without options, each _j_o_b_s_p_e_c is removed from the table of active jobs. If _j_o_b_s_p_e_c is not present, and neither --aa nor --rr is supplied, the shell's notion of the _c_u_r_r_e_n_t _j_o_b is used. If the --hh option is given, each _j_o_b_s_p_e_c is not removed from the ta- ble, but is marked so that SSIIGGHHUUPP is not sent to the job if the shell receives a SSIIGGHHUUPP. If no _j_o_b_s_p_e_c is present, and neither the --aa nor the --rr option is supplied, the _c_u_r_r_e_n_t _j_o_b is used. If no _j_o_b_s_p_e_c is supplied, the --aa option means to remove or mark all jobs; the --rr option without a _j_o_b_s_p_e_c argument restricts operation to running jobs. The return value is 0 unless a _j_o_b_- _s_p_e_c does not specify a valid job. eecchhoo [--nneeEE] [_a_r_g ...] Output the _a_r_gs, separated by spaces, followed by a newline. The return status is always 0. If --nn is specified, the trailing newline is suppressed. If the --ee option is given, interpreta- tion of the following backslash-escaped characters is enabled. The --EE option disables the interpretation of these escape char- acters, even on systems where they are interpreted by default. The xxppgg__eecchhoo shell option may be used to dynamically determine whether or not eecchhoo expands these escape characters by default. eecchhoo does not interpret ---- to mean the end of options. eecchhoo interprets the following escape sequences: \\aa alert (bell) \\bb backspace \\cc suppress further output \\ee \\EE an escape character \\ff form feed \\nn new line \\rr carriage return \\tt horizontal tab \\vv vertical tab \\\\ backslash \\00_n_n_n the eight-bit character whose value is the octal value _n_n_n (zero to three octal digits) \\xx_H_H the eight-bit character whose value is the hexadecimal value _H_H (one or two hex digits) \\uu_H_H_H_H the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value _H_H_H_H (one to four hex digits) \\UU_H_H_H_H_H_H_H_H the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value _H_H_H_H_H_H_H_H (one to eight hex digits) eennaabbllee [--aa] [--ddnnppss] [--ff _f_i_l_e_n_a_m_e] [_n_a_m_e ...] Enable and disable builtin shell commands. Disabling a builtin allows a disk command which has the same name as a shell builtin to be executed without specifying a full pathname, even though the shell normally searches for builtins before disk commands. If --nn is used, each _n_a_m_e is disabled; otherwise, _n_a_m_e_s are enabled. For example, to use the tteesstt binary found via the PPAATTHH instead of the shell builtin version, run ``enable -n test''. The --ff option means to load the new builtin command _n_a_m_e from shared object _f_i_l_e_n_a_m_e, on systems that support dynamic loading. The --dd option will delete a builtin previously loaded with --ff. If no _n_a_m_e arguments are given, or if the --pp option is supplied, a list of shell builtins is printed. With no other option argu- ments, the list consists of all enabled shell builtins. If --nn is supplied, only disabled builtins are printed. If --aa is sup- plied, the list printed includes all builtins, with an indica- tion of whether or not each is enabled. If --ss is supplied, the output is restricted to the POSIX _s_p_e_c_i_a_l builtins. The return value is 0 unless a _n_a_m_e is not a shell builtin or there is an error loading a new builtin from a shared object. eevvaall [_a_r_g ...] The _a_r_gs are read and concatenated together into a single com- mand. This command is then read and executed by the shell, and its exit status is returned as the value of eevvaall. If there are no _a_r_g_s, or only null arguments, eevvaall returns 0. eexxeecc [--ccll] [--aa _n_a_m_e] [_c_o_m_m_a_n_d [_a_r_g_u_m_e_n_t_s]] If _c_o_m_m_a_n_d is specified, it replaces the shell. No new process is created. The _a_r_g_u_m_e_n_t_s become the arguments to _c_o_m_m_a_n_d. If the --ll option is supplied, the shell places a dash at the begin- ning of the zeroth argument passed to _c_o_m_m_a_n_d. This is what _l_o_g_i_n(1) does. The --cc option causes _c_o_m_m_a_n_d to be executed with an empty environment. If --aa is supplied, the shell passes _n_a_m_e as the zeroth argument to the executed command. If _c_o_m_m_a_n_d can- not be executed for some reason, a non-interactive shell exits, unless the shell option eexxeeccffaaiill is enabled, in which case it returns failure. An interactive shell returns failure if the file cannot be executed. If _c_o_m_m_a_n_d is not specified, any redi- rections take effect in the current shell, and the return status is 0. If there is a redirection error, the return status is 1. eexxiitt [_n] Cause the shell to exit with a status of _n. If _n is omitted, the exit status is that of the last command executed. A trap on EEXXIITT is executed before the shell terminates. eexxppoorrtt [--ffnn] [_n_a_m_e[=_w_o_r_d]] ... eexxppoorrtt --pp The supplied _n_a_m_e_s are marked for automatic export to the envi- ronment of subsequently executed commands. If the --ff option is given, the _n_a_m_e_s refer to functions. If no _n_a_m_e_s are given, or if the --pp option is supplied, a list of all names that are exported in this shell is printed. The --nn option causes the export property to be removed from each _n_a_m_e. If a variable name is followed by =_w_o_r_d, the value of the variable is set to _w_o_r_d. eexxppoorrtt returns an exit status of 0 unless an invalid option is encountered, one of the _n_a_m_e_s is not a valid shell variable name, or --ff is supplied with a _n_a_m_e that is not a func- tion.
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