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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 */
42int 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 */
54int 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 */
68char *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 */
83char *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 */
100size_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 */
118size_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 */
132size_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 */
140static 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 */
156char *av_asprintf(const char *fmt, ...) av_printf_format(1, 2);
157
158/**
159 * Convert a number to an av_malloced string.
160 */
161char *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 */
177char *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 */
201char *av_strtok(char *s, const char *delim, char **saveptr);
202
203/**
204 * Locale-independent conversion of ASCII isdigit.
205 */
206static 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 */
214static 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 */
222static 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 */
231static 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 */
241static 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 */
251static 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 */
261int 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 */
267int 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 */
275const 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 */
283const 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 */
296int 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 */
306char *av_append_path_component(const char *path, const char *component);
307
308enum AVEscapeMode {
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 */
347av_warn_unused_result
348int 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 */
387av_warn_unused_result
388int 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 */
396int av_match_list(const char *name, const char *list, char separator);
397
398/**
399 * @}
400 */
401
402#endif /* AVUTIL_AVSTRING_H */
403
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