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getopt.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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  }
58  optopt = c = argv[optind][sp];
59  if (c == ':' || (cp = strchr(opts, c)) == NULL) {
60  fprintf(stderr, ": illegal option -- %c\n", c);
61  if (argv[optind][++sp] == '\0') {
62  optind++;
63  sp = 1;
64  }
65  return '?';
66  }
67  if (*++cp == ':') {
68  if (argv[optind][sp+1] != '\0')
69  optarg = &argv[optind++][sp+1];
70  else if(++optind >= argc) {
71  fprintf(stderr, ": option requires an argument -- %c\n", c);
72  sp = 1;
73  return '?';
74  } else
75  optarg = argv[optind++];
76  sp = 1;
77  } else {
78  if (argv[optind][++sp] == '\0') {
79  sp = 1;
80  optind++;
81  }
82  optarg = NULL;
83  }
84 
85  return c;
86 }