commands/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
  13
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <unistd.h>
  19
  20 #include "pax.h"
  21 #include "extern.h"
  22
  23 int
  24 getoldopt(int argc, char **argv, const char *optstring)
  25 {
  26         static char     *key;           /* Points to next keyletter */
  27         static char     use_getopt;     /* !=0 if argv[1][0] was '-' */
  28         char            c;
  29         char            *place;
  30
  31         optarg = NULL;
  32
  33         if (key == NULL) {              /* First time */
  34                 if (argc < 2) return EOF;
  35                 key = argv[1];
  36                 if (*key == '-')
  37                         use_getopt++;
  38                 else
  39                         optind = 2;
  40         }
  41
  42         if (use_getopt)
  43                 return getopt(argc, argv, optstring);
  44
  45         c = *key++;
  46         if (c == '\0') {
  47                 key--;
  48                 return EOF;
  49         }
  50         place = strchr(optstring, c);
  51
  52         if (place == NULL || c == ':') {
  53                 fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
  54                 return('?');
  55         }
  56
  57         place++;
  58         if (*place == ':') {
  59                 if (optind < argc) {
  60                         optarg = argv[optind];
  61                         optind++;
  62                 } else {
  63                         fprintf(stderr, "%s: %c argument missing\n",
  64                                 argv[0], c);
  65                         return('?');
  66                 }
  67         }
  68
  69         return(c);
  70 }