/*      $OpenBSD: getoldopt.c,v 1.4 2000/01/22 20:24:51 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 Pubic Domain for your edification and enjoyment.
 *
 * $FreeBSD: src/bin/pax/getoldopt.c,v 1.1.2.1 2001/08/01 05:03:11 obrien Exp $
 * $DragonFly: src/bin/pax/getoldopt.c,v 1.3 2003/09/28 14:39:14 hmp Exp $
 */

#include <stdio.h>
#include <string.h>
#include <unistd.h>

int
getoldopt(int argc, char **argv, 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 EOF;
                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 EOF;
        }
        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);
}