/* subgetopt.c, subgetopt.h: (yet another) improved getopt clone, inner layer

D. J. Bernstein, djb@pobox.com.

No dependencies.

No system requirements.

19970228: Cleanups.

931129: Adapted from getopt.c.

No known patent problems.

Documentation in subgetopt.3.

*/

#define SUBGETOPTNOSHORT

#include "subgetopt.h"

#define sgopt subgetopt

#define optind subgetoptind

#define optpos subgetoptpos

#define optarg subgetoptarg

#define optproblem subgetoptproblem

#define optdone subgetoptdone

int optind = 1;

int optpos = 0;

char *optarg = 0;

int optproblem = 0;

int optdone = SUBGETOPTDONE;

int sgopt(argc,argv,opts)

int argc;

char **argv;

char *opts;

{

  int c;

  char *s;

  optarg = 0;

  if (!argv || (optind >= argc) || !argv[optind]) return optdone;

  if (optpos && !argv[optind][optpos]) {

    ++optind;

    optpos = 0;

    if ((optind >= argc) || !argv[optind]) return optdone;

  }

  if (!optpos) {

    if (argv[optind][0] != '-') return optdone;

    ++optpos;

    c = argv[optind][1];

    if ((c == '-') || (c == 0)) {

      if (c) ++optind;

      optpos = 0;

      return optdone;

    }

    /* otherwise c is reassigned below */

  }

  c = argv[optind][optpos];

  ++optpos;

  s = opts;

  while (*s) {

    if (c == *s) {

      if (s[1] == ':') {

        optarg = argv[optind] + optpos;

        ++optind;

        optpos = 0;

        if (!*optarg) {

          optarg = argv[optind];

          if ((optind >= argc) || !optarg) { /* argument past end */

            optproblem = c;

            return '?';

          }

	  ++optind;

        }

      }

      return c;

    }

    ++s;

    if (*s == ':') ++s;

  }

  optproblem = c;

  return '?';

}