compat/getopt.c

   1 /*
   2  * This file is part of Libav.
   3  *
   4  * Libav is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * Libav is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with Libav; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 /*
  20  * This file was copied from the following newsgroup posting:
  21  *
  22  * Newsgroups: mod.std.unix
  23  * Subject: public domain AT&T getopt source
  24  * Date: 3 Nov 85 19:34:15 GMT
  25  *
  26  * Here's something you've all been waiting for:  the AT&T public domain
  27  * source for getopt(3).  It is the code which was given out at the 1985
  28  * UNIFORUM conference in Dallas.  I obtained it by electronic mail
  29  * directly from AT&T.  The people there assure me that it is indeed
  30  * in the public domain.
  31  */
  32
  33 #include <stdio.h>
  34 #include <string.h>
  35
  36 static int opterr = 1;
  37 static int optind = 1;
  38 static int optopt;
  39 static char *optarg;
  40
  41 #undef fprintf
  42
  43 static int getopt(int argc, char *argv[], char *opts)
  44 {
  45     static int sp = 1;
  46     int c;
  47     char *cp;
  48
  49     if (sp == 1)
  50         if (optind >= argc ||
  51             argv[optind][0] != '-' || argv[optind][1] == '\0')
  52             return EOF;
  53         else if (!strcmp(argv[optind], "--")) {
  54             optind++;
  55             return EOF;
  56         }
  57     optopt = c = argv[optind][sp];
  58     if (c == ':' || (cp = strchr(opts, c)) == NULL) {
  59         fprintf(stderr, ": illegal option -- %c\n", c);
  60         if (argv[optind][++sp] == '\0') {
  61             optind++;
  62             sp = 1;
  63         }
  64         return '?';
  65     }
  66     if (*++cp == ':') {
  67         if (argv[optind][sp+1] != '\0')
  68             optarg = &argv[optind++][sp+1];
  69         else if(++optind >= argc) {
  70             fprintf(stderr, ": option requires an argument -- %c\n", c);
  71             sp = 1;
  72             return '?';
  73         } else
  74             optarg = argv[optind++];
  75         sp = 1;
  76     } else {
  77         if (argv[optind][++sp] == '\0') {
  78             sp = 1;
  79             optind++;
  80         }
  81         optarg = NULL;
  82     }
  83
  84     return c;
  85 }