source: freewrt/tools/paxmirabilis/getoldopt.c@ c6ac237

/*      $OpenBSD: getoldopt.c,v 1.8 2003/07/02 21:19:33 deraadt Exp $   */
/*      $NetBSD: getoldopt.c,v 1.3 1995/03/21 09:07:28 cgd Exp $        */

/*
 * Plug-compatible replacement for getopt() for parsing tar-like
 * arguments.  If the first argument begins with "-", it uses getopt;
 * otherwise, it uses the old rules used by tar, dump, and ps.
 *
 * Written 25 August 1985 by John Gilmore (ihnp4!hoptoad!gnu) and placed
 * in the Public Domain for your edification and enjoyment.
 */

#ifndef lint
static const char rcsid[] = "$OpenBSD: getoldopt.c,v 1.8 2003/07/02 21:19:33 deraadt Exp $";
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "pax.h"
#include "extern.h"

int
getoldopt(int argc, char **argv, const char *optstring)
{
        static char     *key;           /* Points to next keyletter */
        static char     use_getopt;     /* !=0 if argv[1][0] was '-' */
        char            c;
        char            *place;

        optarg = NULL;

        if (key == NULL) {              /* First time */
                if (argc < 2)
                        return (-1);
                key = argv[1];
                if (*key == '-')
                        use_getopt++;
                else
                        optind = 2;
        }

        if (use_getopt)
                return (getopt(argc, argv, optstring));

        c = *key++;
        if (c == '\0') {
                key--;
                return (-1);
        }
        place = strchr(optstring, c);

        if (place == NULL || c == ':') {
                fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
                return ('?');
        }

        place++;
        if (*place == ':') {
                if (optind < argc) {
                        optarg = argv[optind];
                        optind++;
                } else {
                        fprintf(stderr, "%s: %c argument missing\n",
                                argv[0], c);
                        return ('?');
                }
        }

        return (c);
}