bin/pax/getoldopt.c

   1 /*      $OpenBSD: getoldopt.c,v 1.9 2009/10/27 23:59:22 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/types.h>
  14 #include <sys/stat.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18 #include "pax.h"
  19 #include "extern.h"
  20
  21 int
  22 getoldopt(int argc, char **argv, const char *optstring)
  23 {
  24         static char     *key;           /* Points to next keyletter */
  25         static char     use_getopt;     /* !=0 if argv[1][0] was '-' */
  26         char            c;
  27         char            *place;
  28
  29         optarg = NULL;
  30
  31         if (key == NULL) {              /* First time */
  32                 if (argc < 2)
  33                         return (-1);
  34                 key = argv[1];
  35                 if (*key == '-')
  36                         use_getopt++;
  37                 else
  38                         optind = 2;
  39         }
  40
  41         if (use_getopt)
  42                 return (getopt(argc, argv, optstring));
  43
  44         c = *key++;
  45         if (c == '\0') {
  46                 key--;
  47                 return (-1);
  48         }
  49         place = strchr(optstring, c);
  50
  51         if (place == NULL || c == ':') {
  52                 fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
  53                 return ('?');
  54         }
  55
  56         place++;
  57         if (*place == ':') {
  58                 if (optind < argc) {
  59                         optarg = argv[optind];
  60                         optind++;
  61                 } else {
  62                         fprintf(stderr, "%s: %c argument missing\n",
  63                                 argv[0], c);
  64                         return ('?');
  65                 }
  66         }
  67
  68         return (c);
  69 }