IRIX Base Documentation 2002 November/SGI IRIX Base Documentation 2002 November.iso/usr/share/catman/u_man/cat1/getopts.z/getopts

Text File | 2002-10-03 | 5.7 KB | 133 lines

GGGGEEEETTTTOOOOPPPPTTTTSSSS((((1111))))                                                          GGGGEEEETTTTOOOOPPPPTTTTSSSS((((1111))))



NNNNAAAAMMMMEEEE
     getopts, getoptcvt - parse command options

SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
     ggggeeeettttooooppppttttssss optstring name [arg ...]

     ////uuuussssrrrr////lllliiiibbbb////ggggeeeettttooooppppttttccccvvvvtttt [----bbbb] file

DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
     _g_e_t_o_p_t_s is a built-in command to _s_h(1) used to parse positional
     parameters and to check for legal options.  It supports all applicable
     rules of the command syntax standard (see Rules 3-10, _i_n_t_r_o(1)).  It
     should be used in place of the _g_e_t_o_p_t(1) command.  See the WWWWAAAARRRRNNNNIIIINNNNGGGGSSSS
     section below.

     _o_p_t_s_t_r_i_n_g must contain the option letters the command using _g_e_t_o_p_t_s will
     recognize; if a letter is followed by a colon, the option is expected to
     have an argument, or group of arguments, which must be separated from it
     by white space.

     Each time it is invoked, _g_e_t_o_p_t_s will place the next option in the shell
     variable _n_a_m_e and the index of the next argument to be processed in the
     shell variable OOOOPPPPTTTTIIIINNNNDDDD.  Whenever the shell or a shell procedure is
     invoked, OOOOPPPPTTTTIIIINNNNDDDD is initialized to 1111.

     When an option requires an option-argument, _g_e_t_o_p_t_s places it in the
     shell variable OOOOPPPPTTTTAAAARRRRGGGG.

     If an illegal option is encountered, ???? will be placed in _n_a_m_e.

     When the end of options is encountered, _g_e_t_o_p_t_s exits with a non-zero
     exit status.  The special option ``--------'' may be used to delimit the end of
     the options.

     By default, _g_e_t_o_p_t_s parses the positional parameters.  If extra arguments
     (_a_r_g ...)  are given on the _g_e_t_o_p_t_s command line, _g_e_t_o_p_t_s will parse them
     instead.

     /_u_s_r/_l_i_b/_g_e_t_o_p_t_c_v_t reads the shell script in _f_i_l_e, converts it to use
     _g_e_t_o_p_t_s(1) instead of _g_e_t_o_p_t(1), and writes the results on the standard
     output.

     ----bbbb   the results of running /_u_s_r/_l_i_b/_g_e_t_o_p_t_c_v_t will be portable to
          earlier releases of the UNIX system.  /_u_s_r/_l_i_b/_g_e_t_o_p_t_c_v_t modifies
          the shell script in _f_i_l_e so that when the resulting shell script is
          executed, it determines at run time whether to invoke _g_e_t_o_p_t_s(1) or
          _g_e_t_o_p_t(1).

     So all new commands will adhere to the command syntax standard described
     in _i_n_t_r_o(1), they should use _g_e_t_o_p_t_s(1) or _g_e_t_o_p_t(3C) to parse positional
     parameters and check for options that are legal for that command (see the
     WWWWAAAARRRRNNNNIIIINNNNGGGGSSSS section below).



                                                                        PPPPaaaaggggeeee 1111






GGGGEEEETTTTOOOOPPPPTTTTSSSS((((1111))))                                                          GGGGEEEETTTTOOOOPPPPTTTTSSSS((((1111))))



EEEEXXXXAAAAMMMMPPPPLLLLEEEE
     The following fragment of a shell program shows how one might process the
     arguments for a command that can take the options aaaa or bbbb, as well as the
     option oooo, which requires an option-argument:

          while getopts abo: c
          do
               case $c in
               a | b)    FLAG=$c;;
               o)        OARG=$OPTARG;;
               \?)       echo $USAGE
                         exit 2;;
               esac
          done
          shift `expr $OPTIND - 1`

     This code will accept any of the following as equivalent:

          cmd -a -b -o "xxx z yy" file
          cmd -a -b -o "xxx z yy" -- file
          cmd -ab -o xxx,z,yy file
          cmd -ab -o "xxx z yy" file
          cmd -o xxx,z,yy -b -a file

SSSSEEEEEEEE AAAALLLLSSSSOOOO
     intro(1), sh(1), getopt(3C)

WWWWAAAARRRRNNNNIIIINNNNGGGGSSSS
     Although the following command syntax rule (see _i_n_t_r_o(1)) relaxations are
     permitted under the current implementation, they should not be used
     because they may not be supported in future releases of the system.  As
     in the EEEEXXXXAAAAMMMMPPPPLLLLEEEE section above, aaaa and bbbb are options, and the option oooo
     requires an option-argument:

          cmd -aboxxx file  (Rule 5 violation:  options with
                option-arguments must not be grouped with other options)
          cmd -ab -oxxx file  (Rule 6 violation:  there must be
                white space after an option that takes an option-argument)

     Changing the value of the shell variable OOOOPPPPTTTTIIIINNNNDDDD or parsing different sets
     of arguments may lead to unexpected results.

DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
     _g_e_t_o_p_t_s prints an error message on the standard error when it encounters
     an option letter not included in _o_p_t_s_t_r_i_n_g.










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