FFmpeg
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 static int getopt(int argc, char *argv[], char *opts)
42 {
43  static int sp = 1;
44  int c;
45  char *cp;
46 
47  if (sp == 1) {
48  if (optind >= argc ||
49  argv[optind][0] != '-' || argv[optind][1] == '\0')
50  return EOF;
51  else if (!strcmp(argv[optind], "--")) {
52  optind++;
53  return EOF;
54  }
55  }
56  optopt = c = argv[optind][sp];
57  if (c == ':' || !(cp = strchr(opts, c))) {
58  fprintf(stderr, ": illegal option -- %c\n", c);
59  if (argv[optind][++sp] == '\0') {
60  optind++;
61  sp = 1;
62  }
63  return '?';
64  }
65  if (*++cp == ':') {
66  if (argv[optind][sp+1] != '\0')
67  optarg = &argv[optind++][sp+1];
68  else if(++optind >= argc) {
69  fprintf(stderr, ": option requires an argument -- %c\n", c);
70  sp = 1;
71  return '?';
72  } else
73  optarg = argv[optind++];
74  sp = 1;
75  } else {
76  if (argv[optind][++sp] == '\0') {
77  sp = 1;
78  optind++;
79  }
80  optarg = NULL;
81  }
82 
83  return c;
84 }
#define NULL
Definition: coverity.c:32
static int optopt
Definition: getopt.c:38
static int optind
Definition: getopt.c:37
static int opterr
Definition: getopt.c:36
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
#define sp
Definition: regdef.h:63
AVDictionary * opts
Definition: movenc.c:50
static int getopt(int argc, char *argv[], char *opts)
Definition: getopt.c:41
static char * optarg
Definition: getopt.c:39