GETOPT(3C)               DOMAIN/IX SYS5                GETOPT(3C)



NAME
     getopt - get option letter from argument vector

USAGE
     int getopt(argc, argv, optstring)
     int argc;
     char **argv, *opstring;
     extern char *optarg;
     extern int optind, opterr;


DESCRIPTION
     Getopt returns the next option letter in argv that matches a
     letter in optstring.  Optstring is a string of recognized
     option letters.  If a letter is followed by a colon, the
     option should have an argument.  Optarg is set to point to
     the start of the option argument on return from getopt.

     Getopt places the argv index of the next argument to be pro-
     cessed in optind Because optind is external, it is automati-
     cally set to zero before the first call to getopt.

     When all the options have been processed (i.e., up to the
     first non-option argument), getopt returns EOF.  When spe-
     cial option - (dash) is used to delimit the end of the
     options, getopt returns EOF and ignores the dash.

EXAMPLE
     The code fragment below shows how to process the arguments
     for a command that can take the mutually exclusive options a
     and b, and the options f and o, both of which require argu-
     ments:

       main (argc, argv)
       int argc;
       char **argv;
       {
            int c;
            extern char **optarg;
            extern int optind;
            .
            .
            .
            while ((c = getopt(argc, argv, "abf:o:")) != EOF)
                 switch (c) {
                 case 'a':
                      if (bflg)
                           errflg++;
                      else
                           aflg++;



Printed 12/4/86                                          GETOPT-1

GETOPT(3C)               DOMAIN/IX SYS5                GETOPT(3C)



                      break;
                 case 'b':
                      if (aflg)
                           errflg++;
                      else
                           bproc( );
                      break;
                 case 'f':
                      ifile = optarg;
                      break;
                 case 'o':
                      ofile = optarg;
                      break;
                 case '?':
                      errflg++;
                 }
            if (errflg) {
                 fprintf(stderr, "usage: . . . ");
                 exit (2);
            }
            for ( ; optind < argc; optind++) {
                 if (access(argv[optind], 4)) {
            .
            .
            .
       }


DIAGNOSTICS
     Getopt prints an error message on stderr and returns a ques-
     tion mark (?) when it encounters an option letter that is
     not included in optstring.  This error message may be dis-
     abled by setting opterr to a non-zero value.

RELATED INFORMATION
     getopt(1)

















GETOPT-2                                          Printed 12/4/86