pax/getoldopt.c

   1 /*      $OpenBSD: getoldopt.c,v 1.8 2003/07/02 21:19:33 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 Public Domain for your edification and enjoyment.
  11  */
  12
  13 #include <sys/cdefs.h>
  14 #ifndef lint
  15 __used static const char rcsid[] = "$OpenBSD: getoldopt.c,v 1.8 2003/07/02 21:19:33 deraadt Exp $";
  16 #endif /* not lint */
  17
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include "pax.h"
  24 #include "extern.h"
  25
  26 int
  27 getoldopt(int argc, char **argv, const char *optstring)
  28 {
  29         static char     *key;           /* Points to next keyletter */
  30         static char     use_getopt;     /* !=0 if argv[1][0] was '-' */
  31         char            c;
  32         char            *place;
  33
  34         optarg = NULL;
  35
  36         if (key == NULL) {              /* First time */
  37                 if (argc < 2)
  38                         return (-1);
  39                 key = argv[1];
  40                 if (*key == '-')
  41                         use_getopt++;
  42                 else
  43                         optind = 2;
  44         }
  45
  46         if (use_getopt)
  47                 return (getopt(argc, argv, optstring));
  48
  49         c = *key++;
  50         if (c == '\0') {
  51                 key--;
  52                 return (-1);
  53         }
  54         place = strchr(optstring, c);
  55
  56         if (place == NULL || c == ':') {
  57                 fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
  58                 return ('?');
  59         }
  60
  61         place++;
  62         if (*place == ':') {
  63                 if (optind < argc) {
  64                         optarg = argv[optind];
  65                         optind++;
  66                 } else {
  67                         fprintf(stderr, "%s: %c argument missing\n",
  68                                 argv[0], c);
  69                         return ('?');
  70                 }
  71         }
  72
  73         return (c);
  74 }