bin/pax/getoldopt.c

   1 /*      $OpenBSD: getoldopt.c,v 1.4 2000/01/22 20:24:51 deraadt Exp $   */
   2 /*      $NetBSD: getoldopt.c,v 1.3 1995/03/21 09:07:28 cgd Exp $        */
   3
   4 /*
   5  * Plug-compatible replacement for getopt() for parsing tar-like
   6  * arguments.  If the first argument begins with "-", it uses getopt;
   7  * otherwise, it uses the old rules used by tar, dump, and ps.
   8  *
   9  * Written 25 August 1985 by John Gilmore (ihnp4!hoptoad!gnu) and placed
  10  * in the Pubic Domain for your edification and enjoyment.
  11  *
  12  * $FreeBSD: src/bin/pax/getoldopt.c,v 1.1.2.1 2001/08/01 05:03:11 obrien Exp $
  13  * $DragonFly: src/bin/pax/getoldopt.c,v 1.3 2003/09/28 14:39:14 hmp Exp $
  14  */
  15
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <unistd.h>
  19
  20 int
  21 getoldopt(int argc, char **argv, char *optstring)
  22 {
  23         static char     *key;           /* Points to next keyletter */
  24         static char     use_getopt;     /* !=0 if argv[1][0] was '-' */
  25         char            c;
  26         char            *place;
  27
  28         optarg = NULL;
  29
  30         if (key == NULL) {              /* First time */
  31                 if (argc < 2) return EOF;
  32                 key = argv[1];
  33                 if (*key == '-')
  34                         use_getopt++;
  35                 else
  36                         optind = 2;
  37         }
  38
  39         if (use_getopt)
  40                 return getopt(argc, argv, optstring);
  41
  42         c = *key++;
  43         if (c == '\0') {
  44                 key--;
  45                 return EOF;
  46         }
  47         place = strchr(optstring, c);
  48
  49         if (place == NULL || c == ':') {
  50                 fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
  51                 return('?');
  52         }
  53
  54         place++;
  55         if (*place == ':') {
  56                 if (optind < argc) {
  57                         optarg = argv[optind];
  58                         optind++;
  59                 } else {
  60                         fprintf(stderr, "%s: %c argument missing\n",
  61                                 argv[0], c);
  62                         return('?');
  63                 }
  64         }
  65
  66         return(c);
  67 }