pax/getoldopt.c

   1 /*      $OpenBSD: getoldopt.c,v 1.3 1997/09/01 18:29:52 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 #ifndef lint
  14 static char rcsid[] __attribute__((__unused__)) = "$OpenBSD: getoldopt.c,v 1.3 1997/09/01 18:29:52 deraadt Exp $";
  15 #endif /* not lint */
  16
  17 #include <stdio.h>
  18 #include <string.h>
  19 #include <unistd.h>
  20
  21 int
  22 getoldopt(argc, argv, optstring)
  23         int     argc;
  24         char    **argv;
  25         char    *optstring;
  26 {
  27         extern char     *optarg;        /* Points to next arg */
  28         extern int      optind;         /* Global argv index */
  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) return EOF;
  38                 key = argv[1];
  39                 if (*key == '-')
  40                         use_getopt++;
  41                 else
  42                         optind = 2;
  43         }
  44
  45         if (use_getopt)
  46                 return getopt(argc, argv, optstring);
  47
  48         c = *key++;
  49         if (c == '\0') {
  50                 key--;
  51                 return EOF;
  52         }
  53         place = strchr(optstring, c);
  54
  55         if (place == NULL || c == ':') {
  56                 fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
  57                 return('?');
  58         }
  59
  60         place++;
  61         if (*place == ':') {
  62                 if (optind < argc) {
  63                         optarg = argv[optind];
  64                         optind++;
  65                 } else {
  66                         fprintf(stderr, "%s: %c argument missing\n",
  67                                 argv[0], c);
  68                         return('?');
  69                 }
  70         }
  71
  72         return(c);
  73 }