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avstring.h
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1 /*
2  * Copyright (c) 2007 Mans Rullgard
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 #ifndef AVUTIL_AVSTRING_H
22 #define AVUTIL_AVSTRING_H
23 
24 #include <stddef.h>
25 #include <stdint.h>
26 #include "attributes.h"
27 
28 /**
29  * @addtogroup lavu_string
30  * @{
31  */
32 
33 /**
34  * Return non-zero if pfx is a prefix of str. If it is, *ptr is set to
35  * the address of the first character in str after the prefix.
36  *
37  * @param str input string
38  * @param pfx prefix to test
39  * @param ptr updated if the prefix is matched inside str
40  * @return non-zero if the prefix matches, zero otherwise
41  */
42 int av_strstart(const char *str, const char *pfx, const char **ptr);
43 
44 /**
45  * Return non-zero if pfx is a prefix of str independent of case. If
46  * it is, *ptr is set to the address of the first character in str
47  * after the prefix.
48  *
49  * @param str input string
50  * @param pfx prefix to test
51  * @param ptr updated if the prefix is matched inside str
52  * @return non-zero if the prefix matches, zero otherwise
53  */
54 int av_stristart(const char *str, const char *pfx, const char **ptr);
55 
56 /**
57  * Locate the first case-independent occurrence in the string haystack
58  * of the string needle. A zero-length string needle is considered to
59  * match at the start of haystack.
60  *
61  * This function is a case-insensitive version of the standard strstr().
62  *
63  * @param haystack string to search in
64  * @param needle string to search for
65  * @return pointer to the located match within haystack
66  * or a null pointer if no match
67  */
68 char *av_stristr(const char *haystack, const char *needle);
69 
70 /**
71  * Locate the first occurrence of the string needle in the string haystack
72  * where not more than hay_length characters are searched. A zero-length
73  * string needle is considered to match at the start of haystack.
74  *
75  * This function is a length-limited version of the standard strstr().
76  *
77  * @param haystack string to search in
78  * @param needle string to search for
79  * @param hay_length length of string to search in
80  * @return pointer to the located match within haystack
81  * or a null pointer if no match
82  */
83 char *av_strnstr(const char *haystack, const char *needle, size_t hay_length);
84 
85 /**
86  * Copy the string src to dst, but no more than size - 1 bytes, and
87  * null-terminate dst.
88  *
89  * This function is the same as BSD strlcpy().
90  *
91  * @param dst destination buffer
92  * @param src source string
93  * @param size size of destination buffer
94  * @return the length of src
95  *
96  * @warning since the return value is the length of src, src absolutely
97  * _must_ be a properly 0-terminated string, otherwise this will read beyond
98  * the end of the buffer and possibly crash.
99  */
100 size_t av_strlcpy(char *dst, const char *src, size_t size);
101 
102 /**
103  * Append the string src to the string dst, but to a total length of
104  * no more than size - 1 bytes, and null-terminate dst.
105  *
106  * This function is similar to BSD strlcat(), but differs when
107  * size <= strlen(dst).
108  *
109  * @param dst destination buffer
110  * @param src source string
111  * @param size size of destination buffer
112  * @return the total length of src and dst
113  *
114  * @warning since the return value use the length of src and dst, these
115  * absolutely _must_ be a properly 0-terminated strings, otherwise this
116  * will read beyond the end of the buffer and possibly crash.
117  */
118 size_t av_strlcat(char *dst, const char *src, size_t size);
119 
120 /**
121  * Append output to a string, according to a format. Never write out of
122  * the destination buffer, and always put a terminating 0 within
123  * the buffer.
124  * @param dst destination buffer (string to which the output is
125  * appended)
126  * @param size total size of the destination buffer
127  * @param fmt printf-compatible format string, specifying how the
128  * following parameters are used
129  * @return the length of the string that would have been generated
130  * if enough space had been available
131  */
132 size_t av_strlcatf(char *dst, size_t size, const char *fmt, ...) av_printf_format(3, 4);
133 
134 /**
135  * Get the count of continuous non zero chars starting from the beginning.
136  *
137  * @param len maximum number of characters to check in the string, that
138  * is the maximum value which is returned by the function
139  */
140 static inline size_t av_strnlen(const char *s, size_t len)
141 {
142  size_t i;
143  for (i = 0; i < len && s[i]; i++)
144  ;
145  return i;
146 }
147 
148 /**
149  * Print arguments following specified format into a large enough auto
150  * allocated buffer. It is similar to GNU asprintf().
151  * @param fmt printf-compatible format string, specifying how the
152  * following parameters are used.
153  * @return the allocated string
154  * @note You have to free the string yourself with av_free().
155  */
156 char *av_asprintf(const char *fmt, ...) av_printf_format(1, 2);
157 
158 /**
159  * Convert a number to an av_malloced string.
160  */
161 char *av_d2str(double d);
162 
163 /**
164  * Unescape the given string until a non escaped terminating char,
165  * and return the token corresponding to the unescaped string.
166  *
167  * The normal \ and ' escaping is supported. Leading and trailing
168  * whitespaces are removed, unless they are escaped with '\' or are
169  * enclosed between ''.
170  *
171  * @param buf the buffer to parse, buf will be updated to point to the
172  * terminating char
173  * @param term a 0-terminated list of terminating chars
174  * @return the malloced unescaped string, which must be av_freed by
175  * the user, NULL in case of allocation failure
176  */
177 char *av_get_token(const char **buf, const char *term);
178 
179 /**
180  * Split the string into several tokens which can be accessed by
181  * successive calls to av_strtok().
182  *
183  * A token is defined as a sequence of characters not belonging to the
184  * set specified in delim.
185  *
186  * On the first call to av_strtok(), s should point to the string to
187  * parse, and the value of saveptr is ignored. In subsequent calls, s
188  * should be NULL, and saveptr should be unchanged since the previous
189  * call.
190  *
191  * This function is similar to strtok_r() defined in POSIX.1.
192  *
193  * @param s the string to parse, may be NULL
194  * @param delim 0-terminated list of token delimiters, must be non-NULL
195  * @param saveptr user-provided pointer which points to stored
196  * information necessary for av_strtok() to continue scanning the same
197  * string. saveptr is updated to point to the next character after the
198  * first delimiter found, or to NULL if the string was terminated
199  * @return the found token, or NULL when no token is found
200  */
201 char *av_strtok(char *s, const char *delim, char **saveptr);
202 
203 /**
204  * Locale-independent conversion of ASCII isdigit.
205  */
206 static inline av_const int av_isdigit(int c)
207 {
208  return c >= '0' && c <= '9';
209 }
210 
211 /**
212  * Locale-independent conversion of ASCII isgraph.
213  */
214 static inline av_const int av_isgraph(int c)
215 {
216  return c > 32 && c < 127;
217 }
218 
219 /**
220  * Locale-independent conversion of ASCII isspace.
221  */
222 static inline av_const int av_isspace(int c)
223 {
224  return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' ||
225  c == '\v';
226 }
227 
228 /**
229  * Locale-independent conversion of ASCII characters to uppercase.
230  */
231 static inline av_const int av_toupper(int c)
232 {
233  if (c >= 'a' && c <= 'z')
234  c ^= 0x20;
235  return c;
236 }
237 
238 /**
239  * Locale-independent conversion of ASCII characters to lowercase.
240  */
241 static inline av_const int av_tolower(int c)
242 {
243  if (c >= 'A' && c <= 'Z')
244  c ^= 0x20;
245  return c;
246 }
247 
248 /**
249  * Locale-independent conversion of ASCII isxdigit.
250  */
251 static inline av_const int av_isxdigit(int c)
252 {
253  c = av_tolower(c);
254  return av_isdigit(c) || (c >= 'a' && c <= 'f');
255 }
256 
257 /**
258  * Locale-independent case-insensitive compare.
259  * @note This means only ASCII-range characters are case-insensitive
260  */
261 int av_strcasecmp(const char *a, const char *b);
262 
263 /**
264  * Locale-independent case-insensitive compare.
265  * @note This means only ASCII-range characters are case-insensitive
266  */
267 int av_strncasecmp(const char *a, const char *b, size_t n);
268 
269 
270 /**
271  * Thread safe basename.
272  * @param path the path, on DOS both \ and / are considered separators.
273  * @return pointer to the basename substring.
274  */
275 const char *av_basename(const char *path);
276 
277 /**
278  * Thread safe dirname.
279  * @param path the path, on DOS both \ and / are considered separators.
280  * @return the path with the separator replaced by the string terminator or ".".
281  * @note the function may change the input string.
282  */
283 const char *av_dirname(char *path);
284 
285 /**
286  * Match instances of a name in a comma-separated list of names.
287  * List entries are checked from the start to the end of the names list,
288  * the first match ends further processing. If an entry prefixed with '-'
289  * matches, then 0 is returned. The "ALL" list entry is considered to
290  * match all names.
291  *
292  * @param name Name to look for.
293  * @param names List of names.
294  * @return 1 on match, 0 otherwise.
295  */
296 int av_match_name(const char *name, const char *names);
297 
298 /**
299  * Append path component to the existing path.
300  * Path separator '/' is placed between when needed.
301  * Resulting string have to be freed with av_free().
302  * @param path base path
303  * @param component component to be appended
304  * @return new path or NULL on error.
305  */
306 char *av_append_path_component(const char *path, const char *component);
307 
309  AV_ESCAPE_MODE_AUTO, ///< Use auto-selected escaping mode.
310  AV_ESCAPE_MODE_BACKSLASH, ///< Use backslash escaping.
311  AV_ESCAPE_MODE_QUOTE, ///< Use single-quote escaping.
312 };
313 
314 /**
315  * Consider spaces special and escape them even in the middle of the
316  * string.
317  *
318  * This is equivalent to adding the whitespace characters to the special
319  * characters lists, except it is guaranteed to use the exact same list
320  * of whitespace characters as the rest of libavutil.
321  */
322 #define AV_ESCAPE_FLAG_WHITESPACE (1 << 0)
323 
324 /**
325  * Escape only specified special characters.
326  * Without this flag, escape also any characters that may be considered
327  * special by av_get_token(), such as the single quote.
328  */
329 #define AV_ESCAPE_FLAG_STRICT (1 << 1)
330 
331 /**
332  * Escape string in src, and put the escaped string in an allocated
333  * string in *dst, which must be freed with av_free().
334  *
335  * @param dst pointer where an allocated string is put
336  * @param src string to escape, must be non-NULL
337  * @param special_chars string containing the special characters which
338  * need to be escaped, can be NULL
339  * @param mode escape mode to employ, see AV_ESCAPE_MODE_* macros.
340  * Any unknown value for mode will be considered equivalent to
341  * AV_ESCAPE_MODE_BACKSLASH, but this behaviour can change without
342  * notice.
343  * @param flags flags which control how to escape, see AV_ESCAPE_FLAG_ macros
344  * @return the length of the allocated string, or a negative error code in case of error
345  * @see av_bprint_escape()
346  */
348 int av_escape(char **dst, const char *src, const char *special_chars,
349  enum AVEscapeMode mode, int flags);
350 
351 #define AV_UTF8_FLAG_ACCEPT_INVALID_BIG_CODES 1 ///< accept codepoints over 0x10FFFF
352 #define AV_UTF8_FLAG_ACCEPT_NON_CHARACTERS 2 ///< accept non-characters - 0xFFFE and 0xFFFF
353 #define AV_UTF8_FLAG_ACCEPT_SURROGATES 4 ///< accept UTF-16 surrogates codes
354 #define AV_UTF8_FLAG_EXCLUDE_XML_INVALID_CONTROL_CODES 8 ///< exclude control codes not accepted by XML
355 
356 #define AV_UTF8_FLAG_ACCEPT_ALL \
357  AV_UTF8_FLAG_ACCEPT_INVALID_BIG_CODES|AV_UTF8_FLAG_ACCEPT_NON_CHARACTERS|AV_UTF8_FLAG_ACCEPT_SURROGATES
358 
359 /**
360  * Read and decode a single UTF-8 code point (character) from the
361  * buffer in *buf, and update *buf to point to the next byte to
362  * decode.
363  *
364  * In case of an invalid byte sequence, the pointer will be updated to
365  * the next byte after the invalid sequence and the function will
366  * return an error code.
367  *
368  * Depending on the specified flags, the function will also fail in
369  * case the decoded code point does not belong to a valid range.
370  *
371  * @note For speed-relevant code a carefully implemented use of
372  * GET_UTF8() may be preferred.
373  *
374  * @param codep pointer used to return the parsed code in case of success.
375  * The value in *codep is set even in case the range check fails.
376  * @param bufp pointer to the address the first byte of the sequence
377  * to decode, updated by the function to point to the
378  * byte next after the decoded sequence
379  * @param buf_end pointer to the end of the buffer, points to the next
380  * byte past the last in the buffer. This is used to
381  * avoid buffer overreads (in case of an unfinished
382  * UTF-8 sequence towards the end of the buffer).
383  * @param flags a collection of AV_UTF8_FLAG_* flags
384  * @return >= 0 in case a sequence was successfully read, a negative
385  * value in case of invalid sequence
386  */
388 int av_utf8_decode(int32_t *codep, const uint8_t **bufp, const uint8_t *buf_end,
389  unsigned int flags);
390 
391 /**
392  * Check if a name is in a list.
393  * @returns 0 if not found, or the 1 based index where it has been found in the
394  * list.
395  */
396 int av_match_list(const char *name, const char *list, char separator);
397 
398 /**
399  * @}
400  */
401 
402 #endif /* AVUTIL_AVSTRING_H */
#define av_const
Definition: attributes.h:76
const char * s
Definition: avisynth_c.h:631
av_warn_unused_result int av_utf8_decode(int32_t *codep, const uint8_t **bufp, const uint8_t *buf_end, unsigned int flags)
Read and decode a single UTF-8 code point (character) from the buffer in *buf, and update *buf to poi...
Definition: avstring.c:343
static av_const int av_isdigit(int c)
Locale-independent conversion of ASCII isdigit.
Definition: avstring.h:206
const char * fmt
Definition: avisynth_c.h:632
size_t static size_t av_strnlen(const char *s, size_t len)
Get the count of continuous non zero chars starting from the beginning.
Definition: avstring.h:140
char * av_stristr(const char *haystack, const char *needle)
Locate the first case-independent occurrence in the string haystack of the string needle...
Definition: avstring.c:56
av_warn_unused_result int av_escape(char **dst, const char *src, const char *special_chars, enum AVEscapeMode mode, int flags)
Escape string in src, and put the escaped string in an allocated string in *dst, which must be freed ...
Definition: avstring.c:303
const char * b
Definition: vf_curves.c:113
static av_const int av_isspace(int c)
Locale-independent conversion of ASCII isspace.
Definition: avstring.h:222
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:223
Use backslash escaping.
Definition: avstring.h:310
Macro definitions for various function/variable attributes.
int av_stristart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str independent of case.
Definition: avstring.c:45
const char * av_basename(const char *path)
Thread safe basename.
Definition: avstring.c:234
uint8_t
mode
Definition: f_perms.c:27
char char * av_d2str(double d)
Convert a number to an av_malloced string.
Definition: avstring.c:139
Use single-quote escaping.
Definition: avstring.h:311
ptrdiff_t size
Definition: opengl_enc.c:101
static av_const int av_tolower(int c)
Locale-independent conversion of ASCII characters to lowercase.
Definition: avstring.h:241
int av_match_list(const char *name, const char *list, char separator)
Check if a name is in a list.
Definition: avstring.c:419
int av_match_name(const char *name, const char *names)
Match instances of a name in a comma-separated list of names.
Definition: avstring.c:320
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:83
char * av_get_token(const char **buf, const char *term)
Unescape the given string until a non escaped terminating char, and return the token corresponding to...
Definition: avstring.c:149
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:156
Use auto-selected escaping mode.
Definition: avstring.h:309
int av_strcasecmp(const char *a, const char *b)
Locale-independent case-insensitive compare.
Definition: avstring.c:213
int32_t
int n
Definition: avisynth_c.h:547
#define src
Definition: vp9dsp.c:530
void * buf
Definition: avisynth_c.h:553
static av_const int av_toupper(int c)
Locale-independent conversion of ASCII characters to uppercase.
Definition: avstring.h:231
static av_const int av_isxdigit(int c)
Locale-independent conversion of ASCII isxdigit.
Definition: avstring.h:251
size_t av_strlcat(char *dst, const char *src, size_t size)
Append the string src to the string dst, but to a total length of no more than size - 1 bytes...
Definition: avstring.c:93
static int flags
Definition: cpu.c:47
#define av_warn_unused_result
Definition: attributes.h:56
char * av_strtok(char *s, const char *delim, char **saveptr)
Split the string into several tokens which can be accessed by successive calls to av_strtok()...
Definition: avstring.c:184
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
Definition: avstring.c:34
static av_const int av_isgraph(int c)
Locale-independent conversion of ASCII isgraph.
Definition: avstring.h:214
char * av_append_path_component(const char *path, const char *component)
Append path component to the existing path.
Definition: avstring.c:272
char * av_strnstr(const char *haystack, const char *needle, size_t hay_length)
Locate the first occurrence of the string needle in the string haystack where not more than hay_lengt...
Definition: avstring.c:69
static double c[64]
const char * av_dirname(char *path)
Thread safe dirname.
Definition: avstring.c:251
int len
AVEscapeMode
Definition: avstring.h:308
char * av_asprintf(const char *fmt,...) av_printf_format(1
Print arguments following specified format into a large enough auto allocated buffer.
size_t av_strlcatf(char *dst, size_t size, const char *fmt,...) av_printf_format(3
Append output to a string, according to a format.
const char * name
Definition: opengl_enc.c:103