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avstring.c
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1 /*
2  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3  * Copyright (c) 2007 Mans Rullgard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <stdarg.h>
23 #include <stdint.h>
24 #include <stdio.h>
25 #include <string.h>
26 
27 #include "config.h"
28 #include "common.h"
29 #include "mem.h"
30 #include "avassert.h"
31 #include "avstring.h"
32 #include "bprint.h"
33 
34 int av_strstart(const char *str, const char *pfx, const char **ptr)
35 {
36  while (*pfx && *pfx == *str) {
37  pfx++;
38  str++;
39  }
40  if (!*pfx && ptr)
41  *ptr = str;
42  return !*pfx;
43 }
44 
45 int av_stristart(const char *str, const char *pfx, const char **ptr)
46 {
47  while (*pfx && av_toupper((unsigned)*pfx) == av_toupper((unsigned)*str)) {
48  pfx++;
49  str++;
50  }
51  if (!*pfx && ptr)
52  *ptr = str;
53  return !*pfx;
54 }
55 
56 char *av_stristr(const char *s1, const char *s2)
57 {
58  if (!*s2)
59  return (char*)(intptr_t)s1;
60 
61  do
62  if (av_stristart(s1, s2, NULL))
63  return (char*)(intptr_t)s1;
64  while (*s1++);
65 
66  return NULL;
67 }
68 
69 char *av_strnstr(const char *haystack, const char *needle, size_t hay_length)
70 {
71  size_t needle_len = strlen(needle);
72  if (!needle_len)
73  return (char*)haystack;
74  while (hay_length >= needle_len) {
75  hay_length--;
76  if (!memcmp(haystack, needle, needle_len))
77  return (char*)haystack;
78  haystack++;
79  }
80  return NULL;
81 }
82 
83 size_t av_strlcpy(char *dst, const char *src, size_t size)
84 {
85  size_t len = 0;
86  while (++len < size && *src)
87  *dst++ = *src++;
88  if (len <= size)
89  *dst = 0;
90  return len + strlen(src) - 1;
91 }
92 
93 size_t av_strlcat(char *dst, const char *src, size_t size)
94 {
95  size_t len = strlen(dst);
96  if (size <= len + 1)
97  return len + strlen(src);
98  return len + av_strlcpy(dst + len, src, size - len);
99 }
100 
101 size_t av_strlcatf(char *dst, size_t size, const char *fmt, ...)
102 {
103  int len = strlen(dst);
104  va_list vl;
105 
106  va_start(vl, fmt);
107  len += vsnprintf(dst + len, size > len ? size - len : 0, fmt, vl);
108  va_end(vl);
109 
110  return len;
111 }
112 
113 char *av_asprintf(const char *fmt, ...)
114 {
115  char *p = NULL;
116  va_list va;
117  int len;
118 
119  va_start(va, fmt);
120  len = vsnprintf(NULL, 0, fmt, va);
121  va_end(va);
122  if (len < 0)
123  goto end;
124 
125  p = av_malloc(len + 1);
126  if (!p)
127  goto end;
128 
129  va_start(va, fmt);
130  len = vsnprintf(p, len + 1, fmt, va);
131  va_end(va);
132  if (len < 0)
133  av_freep(&p);
134 
135 end:
136  return p;
137 }
138 
139 char *av_d2str(double d)
140 {
141  char *str = av_malloc(16);
142  if (str)
143  snprintf(str, 16, "%f", d);
144  return str;
145 }
146 
147 #define WHITESPACES " \n\t"
148 
149 char *av_get_token(const char **buf, const char *term)
150 {
151  char *out = av_malloc(strlen(*buf) + 1);
152  char *ret = out, *end = out;
153  const char *p = *buf;
154  if (!out)
155  return NULL;
156  p += strspn(p, WHITESPACES);
157 
158  while (*p && !strspn(p, term)) {
159  char c = *p++;
160  if (c == '\\' && *p) {
161  *out++ = *p++;
162  end = out;
163  } else if (c == '\'') {
164  while (*p && *p != '\'')
165  *out++ = *p++;
166  if (*p) {
167  p++;
168  end = out;
169  }
170  } else {
171  *out++ = c;
172  }
173  }
174 
175  do
176  *out-- = 0;
177  while (out >= end && strspn(out, WHITESPACES));
178 
179  *buf = p;
180 
181  return ret;
182 }
183 
184 char *av_strtok(char *s, const char *delim, char **saveptr)
185 {
186  char *tok;
187 
188  if (!s && !(s = *saveptr))
189  return NULL;
190 
191  /* skip leading delimiters */
192  s += strspn(s, delim);
193 
194  /* s now points to the first non delimiter char, or to the end of the string */
195  if (!*s) {
196  *saveptr = NULL;
197  return NULL;
198  }
199  tok = s++;
200 
201  /* skip non delimiters */
202  s += strcspn(s, delim);
203  if (*s) {
204  *s = 0;
205  *saveptr = s+1;
206  } else {
207  *saveptr = NULL;
208  }
209 
210  return tok;
211 }
212 
213 int av_strcasecmp(const char *a, const char *b)
214 {
215  uint8_t c1, c2;
216  do {
217  c1 = av_tolower(*a++);
218  c2 = av_tolower(*b++);
219  } while (c1 && c1 == c2);
220  return c1 - c2;
221 }
222 
223 int av_strncasecmp(const char *a, const char *b, size_t n)
224 {
225  const char *end = a + n;
226  uint8_t c1, c2;
227  do {
228  c1 = av_tolower(*a++);
229  c2 = av_tolower(*b++);
230  } while (a < end && c1 && c1 == c2);
231  return c1 - c2;
232 }
233 
234 const char *av_basename(const char *path)
235 {
236  char *p = strrchr(path, '/');
237 
238 #if HAVE_DOS_PATHS
239  char *q = strrchr(path, '\\');
240  char *d = strchr(path, ':');
241 
242  p = FFMAX3(p, q, d);
243 #endif
244 
245  if (!p)
246  return path;
247 
248  return p + 1;
249 }
250 
251 const char *av_dirname(char *path)
252 {
253  char *p = strrchr(path, '/');
254 
255 #if HAVE_DOS_PATHS
256  char *q = strrchr(path, '\\');
257  char *d = strchr(path, ':');
258 
259  d = d ? d + 1 : d;
260 
261  p = FFMAX3(p, q, d);
262 #endif
263 
264  if (!p)
265  return ".";
266 
267  *p = '\0';
268 
269  return path;
270 }
271 
272 int av_escape(char **dst, const char *src, const char *special_chars,
273  enum AVEscapeMode mode, int flags)
274 {
275  AVBPrint dstbuf;
276 
278  av_bprint_escape(&dstbuf, src, special_chars, mode, flags);
279 
280  if (!av_bprint_is_complete(&dstbuf)) {
281  av_bprint_finalize(&dstbuf, NULL);
282  return AVERROR(ENOMEM);
283  } else {
284  av_bprint_finalize(&dstbuf, dst);
285  return dstbuf.len;
286  }
287 }
288 
289 int av_isdigit(int c)
290 {
291  return c >= '0' && c <= '9';
292 }
293 
294 int av_isgraph(int c)
295 {
296  return c > 32 && c < 127;
297 }
298 
299 int av_isspace(int c)
300 {
301  return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' ||
302  c == '\v';
303 }
304 
305 int av_isxdigit(int c)
306 {
307  c = av_tolower(c);
308  return av_isdigit(c) || (c >= 'a' && c <= 'f');
309 }
310 
311 int av_match_name(const char *name, const char *names)
312 {
313  const char *p;
314  int len, namelen;
315 
316  if (!name || !names)
317  return 0;
318 
319  namelen = strlen(name);
320  while ((p = strchr(names, ','))) {
321  len = FFMAX(p - names, namelen);
322  if (!av_strncasecmp(name, names, len))
323  return 1;
324  names = p + 1;
325  }
326  return !av_strcasecmp(name, names);
327 }
328 
329 int av_utf8_decode(int32_t *codep, const uint8_t **bufp, const uint8_t *buf_end,
330  unsigned int flags)
331 {
332  const uint8_t *p = *bufp;
333  uint32_t top;
334  uint64_t code;
335  int ret = 0, tail_len;
336  uint32_t overlong_encoding_mins[6] = {
337  0x00000000, 0x00000080, 0x00000800, 0x00010000, 0x00200000, 0x04000000,
338  };
339 
340  if (p >= buf_end)
341  return 0;
342 
343  code = *p++;
344 
345  /* first sequence byte starts with 10, or is 1111-1110 or 1111-1111,
346  which is not admitted */
347  if ((code & 0xc0) == 0x80 || code >= 0xFE) {
348  ret = AVERROR(EILSEQ);
349  goto end;
350  }
351  top = (code & 128) >> 1;
352 
353  tail_len = 0;
354  while (code & top) {
355  int tmp;
356  tail_len++;
357  if (p >= buf_end) {
358  (*bufp) ++;
359  return AVERROR(EILSEQ); /* incomplete sequence */
360  }
361 
362  /* we assume the byte to be in the form 10xx-xxxx */
363  tmp = *p++ - 128; /* strip leading 1 */
364  if (tmp>>6) {
365  (*bufp) ++;
366  return AVERROR(EILSEQ);
367  }
368  code = (code<<6) + tmp;
369  top <<= 5;
370  }
371  code &= (top << 1) - 1;
372 
373  /* check for overlong encodings */
374  av_assert0(tail_len <= 5);
375  if (code < overlong_encoding_mins[tail_len]) {
376  ret = AVERROR(EILSEQ);
377  goto end;
378  }
379 
380  if (code >= 1<<31) {
381  ret = AVERROR(EILSEQ); /* out-of-range value */
382  goto end;
383  }
384 
385  *codep = code;
386 
387  if (code > 0x10FFFF &&
389  ret = AVERROR(EILSEQ);
390  if (code < 0x20 && code != 0x9 && code != 0xA && code != 0xD &&
392  ret = AVERROR(EILSEQ);
393  if (code >= 0xD800 && code <= 0xDFFF &&
395  ret = AVERROR(EILSEQ);
396  if ((code == 0xFFFE || code == 0xFFFF) &&
398  ret = AVERROR(EILSEQ);
399 
400 end:
401  *bufp = p;
402  return ret;
403 }
404 
405 #ifdef TEST
406 
407 int main(void)
408 {
409  int i;
410  static const char * const strings[] = {
411  "''",
412  "",
413  ":",
414  "\\",
415  "'",
416  " '' :",
417  " '' '' :",
418  "foo '' :",
419  "'foo'",
420  "foo ",
421  " ' foo ' ",
422  "foo\\",
423  "foo': blah:blah",
424  "foo\\: blah:blah",
425  "foo\'",
426  "'foo : ' :blahblah",
427  "\\ :blah",
428  " foo",
429  " foo ",
430  " foo \\ ",
431  "foo ':blah",
432  " foo bar : blahblah",
433  "\\f\\o\\o",
434  "'foo : \\ \\ ' : blahblah",
435  "'\\fo\\o:': blahblah",
436  "\\'fo\\o\\:': foo ' :blahblah"
437  };
438 
439  printf("Testing av_get_token()\n");
440  for (i = 0; i < FF_ARRAY_ELEMS(strings); i++) {
441  const char *p = strings[i];
442  char *q;
443  printf("|%s|", p);
444  q = av_get_token(&p, ":");
445  printf(" -> |%s|", q);
446  printf(" + |%s|\n", p);
447  av_free(q);
448  }
449 
450  return 0;
451 }
452 
453 #endif /* TEST */