GETOPT(1)           RISC/os Reference Manual            GETOPT(1)



NAME
     getopt - parse command options

SYNOPSIS
     set -- getopt optstring $*

DESCRIPTION
     The getopts command supersedes getopt, which is a built-in
     to the Bourne shell.  For more information, see the NOTES
     below.

     getopt is used to break up options in command lines for easy
     parsing by shell procedures and to check for legal options.
     optstring is a string of recognized option letters; see
     getopt(3C).  If a letter is followed by a colon, the option
     is expected to have an argument which may or may not be
     separated from it by white space.  The special option -- is
     used to delimit the end of the options.  If it is used
     explicitly, getopt recognizes it; otherwise, getopt gen-
     erates it; in either case, getopt places it at the end of
     the options.  The positional parameters ($1 $2 ...) of the
     shell are reset so that each option is preceded by a - and
     is in its own positional parameter; each option argument is
     also parsed into its own positional parameter.

INTERNATIONAL FUNCTIONALITY
     Characters from supplementary code sets can be read as the
     argument to optstring.  Note, however, that the recognized
     string of option letters specified in optstring must be a
     single-byte characters.

EXAMPLE
     The following code fragment shows how one might process the
     arguments for a command that can take the options a or b, as
     well as the option o, which requires an argument:

          set -- getopt abo: $*
          if [ $? != 0 ]
          then
               echo $USAGE
               exit 2
          fi
          for i in $*
          do
               case $i in
               -a | -b)  FLAG=$i; shift;;
               -o)       OARG=$2; shift I;;
               --)       shift; break;;
               esac
          done





                        Printed 11/19/92                   Page 1

GETOPT(1)           RISC/os Reference Manual            GETOPT(1)



     This code accepts any of the following as equivalent:

          cmd -aoarg file file
          cmd -a -o arg file file
          cmd -oarg -a file file
          cmd -a -oarg -- file file

SEE ALSO
     getopts(1), sh(1).
     getopt(3C) in the Programmer's Reference Manual.

DIAGNOSTICS
     getopt prints an error message on the standard error when it
     encounters an option letter not included in optstring.

NOTES
     getopt will not be supported in the next major release.  For
     this release a conversion tool has been provided, getoptcvt.
     For more information about getopts and getoptcvt, see
     getopts(1).

     Reset optind to 1 when rescanning the options.

     getopt does not support the part of Rule 8 of the command
     syntax standard [see intro(1)] that permits groups of
     option-arguments following an option to be separated by
     white space and quoted.  For example,

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

     is not handled correctly.  To correct this deficiency, use
     the getopts command in place of getopt.

     If an option that takes an option-argument is followed by a
     value that is the same as one of the options listed in opt-
     string (referring to the earlier EXAMPLE section, but using
     the following command line:  cmd -o -a file), getopt always
     treats a as an option-argument to o; it never recognizes a
     as an option.  For this case, the for loop in the example
     shifts past the file argument.















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