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ffescape.c
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1 /*
2  * Copyright (c) 2012 Stefano Sabatini
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "config.h"
22 #if HAVE_UNISTD_H
23 #include <unistd.h> /* getopt */
24 #endif
25 
26 #include "libavutil/log.h"
27 #include "libavutil/bprint.h"
28 
29 #if !HAVE_GETOPT
30 #include "compat/getopt.c"
31 #endif
32 
33 /**
34  * @file
35  * escaping utility
36  */
37 
38 static void usage(void)
39 {
40  printf("Escape an input string, adopting the av_get_token() escaping logic\n");
41  printf("usage: ffescape [OPTIONS]\n");
42  printf("\n"
43  "Options:\n"
44  "-e echo each input line on output\n"
45  "-f flag select an escape flag, can assume the values 'whitespace' and 'strict'\n"
46  "-h print this help\n"
47  "-i INFILE set INFILE as input file, stdin if omitted\n"
48  "-l LEVEL set the number of escaping levels, 1 if omitted\n"
49  "-m ESCAPE_MODE select escape mode between 'auto', 'backslash', 'quote'\n"
50  "-o OUTFILE set OUTFILE as output file, stdout if omitted\n"
51  "-p PROMPT set output prompt, is '=> ' by default\n"
52  "-s SPECIAL_CHARS set the list of special characters\n");
53 }
54 
55 int main(int argc, char **argv)
56 {
57  AVBPrint src;
58  char *src_buf, *dst_buf;
59  const char *outfilename = NULL, *infilename = NULL;
60  FILE *outfile = NULL, *infile = NULL;
61  const char *prompt = "=> ";
62  enum AVEscapeMode escape_mode = AV_ESCAPE_MODE_AUTO;
63  int escape_flags = 0;
64  int level = 1;
65  int echo = 0;
66  char *special_chars = NULL;
67  int c;
68 
69  while ((c = getopt(argc, argv, "ef:hi:l:o:m:p:s:")) != -1) {
70  switch (c) {
71  case 'e':
72  echo = 1;
73  break;
74  case 'h':
75  usage();
76  return 0;
77  case 'i':
78  infilename = optarg;
79  break;
80  case 'f':
81  if (!strcmp(optarg, "whitespace")) escape_flags |= AV_ESCAPE_FLAG_WHITESPACE;
82  else if (!strcmp(optarg, "strict")) escape_flags |= AV_ESCAPE_FLAG_STRICT;
83  else {
84  av_log(NULL, AV_LOG_ERROR,
85  "Invalid value '%s' for option -f, "
86  "valid arguments are 'whitespace', and 'strict'\n", optarg);
87  return 1;
88  }
89  break;
90  case 'l':
91  {
92  char *tail;
93  long int li = strtol(optarg, &tail, 10);
94  if (*tail || li > INT_MAX || li < 0) {
95  av_log(NULL, AV_LOG_ERROR,
96  "Invalid value '%s' for option -l, argument must be a non negative integer\n",
97  optarg);
98  return 1;
99  }
100  level = li;
101  break;
102  }
103  case 'm':
104  if (!strcmp(optarg, "auto")) escape_mode = AV_ESCAPE_MODE_AUTO;
105  else if (!strcmp(optarg, "backslash")) escape_mode = AV_ESCAPE_MODE_BACKSLASH;
106  else if (!strcmp(optarg, "quote")) escape_mode = AV_ESCAPE_MODE_QUOTE;
107  else {
108  av_log(NULL, AV_LOG_ERROR,
109  "Invalid value '%s' for option -m, "
110  "valid arguments are 'backslash', and 'quote'\n", optarg);
111  return 1;
112  }
113  break;
114  case 'o':
115  outfilename = optarg;
116  break;
117  case 'p':
118  prompt = optarg;
119  break;
120  case 's':
121  special_chars = optarg;
122  break;
123  case '?':
124  return 1;
125  }
126  }
127 
128  if (!infilename || !strcmp(infilename, "-")) {
129  infilename = "stdin";
130  infile = stdin;
131  } else {
132  infile = fopen(infilename, "r");
133  }
134  if (!infile) {
135  av_log(NULL, AV_LOG_ERROR, "Impossible to open input file '%s': %s\n", infilename, strerror(errno));
136  return 1;
137  }
138 
139  if (!outfilename || !strcmp(outfilename, "-")) {
140  outfilename = "stdout";
141  outfile = stdout;
142  } else {
143  outfile = fopen(outfilename, "w");
144  }
145  if (!outfile) {
146  av_log(NULL, AV_LOG_ERROR, "Impossible to open output file '%s': %s\n", outfilename, strerror(errno));
147  return 1;
148  }
149 
150  /* grab the input and store it in src */
152  while ((c = fgetc(infile)) != EOF)
153  av_bprint_chars(&src, c, 1);
154  av_bprint_chars(&src, 0, 1);
155 
156  if (!av_bprint_is_complete(&src)) {
157  av_log(NULL, AV_LOG_ERROR, "Could not allocate a buffer for the source string\n");
158  av_bprint_finalize(&src, NULL);
159  return 1;
160  }
161  av_bprint_finalize(&src, &src_buf);
162 
163  if (echo)
164  fprintf(outfile, "%s", src_buf);
165 
166  /* escape */
167  dst_buf = src_buf;
168  while (level--) {
169  if (av_escape(&dst_buf, src_buf, special_chars, escape_mode, escape_flags) < 0) {
170  av_log(NULL, AV_LOG_ERROR, "Could not escape string\n");
171  return 1;
172  }
173  av_free(src_buf);
174  src_buf = dst_buf;
175  }
176 
177  fprintf(outfile, "%s%s", prompt, dst_buf);
178  av_free(dst_buf);
179  return 0;
180 }