avstring.h 9.85 KB
Newer Older
wester committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302
/*
 * Copyright (c) 2007 Mans Rullgard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef AVUTIL_AVSTRING_H
#define AVUTIL_AVSTRING_H

#include <stddef.h>
#include "attributes.h"

/**
 * @addtogroup lavu_string
 * @{
 */

/**
 * Return non-zero if pfx is a prefix of str. If it is, *ptr is set to
 * the address of the first character in str after the prefix.
 *
 * @param str input string
 * @param pfx prefix to test
 * @param ptr updated if the prefix is matched inside str
 * @return non-zero if the prefix matches, zero otherwise
 */
int av_strstart(const char *str, const char *pfx, const char **ptr);

/**
 * Return non-zero if pfx is a prefix of str independent of case. If
 * it is, *ptr is set to the address of the first character in str
 * after the prefix.
 *
 * @param str input string
 * @param pfx prefix to test
 * @param ptr updated if the prefix is matched inside str
 * @return non-zero if the prefix matches, zero otherwise
 */
int av_stristart(const char *str, const char *pfx, const char **ptr);

/**
 * Locate the first case-independent occurrence in the string haystack
 * of the string needle.  A zero-length string needle is considered to
 * match at the start of haystack.
 *
 * This function is a case-insensitive version of the standard strstr().
 *
 * @param haystack string to search in
 * @param needle   string to search for
 * @return         pointer to the located match within haystack
 *                 or a null pointer if no match
 */
char *av_stristr(const char *haystack, const char *needle);

/**
 * Locate the first occurrence of the string needle in the string haystack
 * where not more than hay_length characters are searched. A zero-length
 * string needle is considered to match at the start of haystack.
 *
 * This function is a length-limited version of the standard strstr().
 *
 * @param haystack   string to search in
 * @param needle     string to search for
 * @param hay_length length of string to search in
 * @return           pointer to the located match within haystack
 *                   or a null pointer if no match
 */
char *av_strnstr(const char *haystack, const char *needle, size_t hay_length);

/**
 * Copy the string src to dst, but no more than size - 1 bytes, and
 * null-terminate dst.
 *
 * This function is the same as BSD strlcpy().
 *
 * @param dst destination buffer
 * @param src source string
 * @param size size of destination buffer
 * @return the length of src
 *
 * @warning since the return value is the length of src, src absolutely
 * _must_ be a properly 0-terminated string, otherwise this will read beyond
 * the end of the buffer and possibly crash.
 */
size_t av_strlcpy(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, and null-terminate dst.
 *
 * This function is similar to BSD strlcat(), but differs when
 * size <= strlen(dst).
 *
 * @param dst destination buffer
 * @param src source string
 * @param size size of destination buffer
 * @return the total length of src and dst
 *
 * @warning since the return value use the length of src and dst, these
 * absolutely _must_ be a properly 0-terminated strings, otherwise this
 * will read beyond the end of the buffer and possibly crash.
 */
size_t av_strlcat(char *dst, const char *src, size_t size);

/**
 * Append output to a string, according to a format. Never write out of
 * the destination buffer, and always put a terminating 0 within
 * the buffer.
 * @param dst destination buffer (string to which the output is
 *  appended)
 * @param size total size of the destination buffer
 * @param fmt printf-compatible format string, specifying how the
 *  following parameters are used
 * @return the length of the string that would have been generated
 *  if enough space had been available
 */
size_t av_strlcatf(char *dst, size_t size, const char *fmt, ...) av_printf_format(3, 4);

/**
 * Print arguments following specified format into a large enough auto
 * allocated buffer. It is similar to GNU asprintf().
 * @param fmt printf-compatible format string, specifying how the
 *            following parameters are used.
 * @return the allocated string
 * @note You have to free the string yourself with av_free().
 */
char *av_asprintf(const char *fmt, ...) av_printf_format(1, 2);

/**
 * Convert a number to a av_malloced string.
 */
char *av_d2str(double d);

/**
 * Unescape the given string until a non escaped terminating char,
 * and return the token corresponding to the unescaped string.
 *
 * The normal \ and ' escaping is supported. Leading and trailing
 * whitespaces are removed, unless they are escaped with '\' or are
 * enclosed between ''.
 *
 * @param buf the buffer to parse, buf will be updated to point to the
 * terminating char
 * @param term a 0-terminated list of terminating chars
 * @return the malloced unescaped string, which must be av_freed by
 * the user, NULL in case of allocation failure
 */
char *av_get_token(const char **buf, const char *term);

/**
 * Split the string into several tokens which can be accessed by
 * successive calls to av_strtok().
 *
 * A token is defined as a sequence of characters not belonging to the
 * set specified in delim.
 *
 * On the first call to av_strtok(), s should point to the string to
 * parse, and the value of saveptr is ignored. In subsequent calls, s
 * should be NULL, and saveptr should be unchanged since the previous
 * call.
 *
 * This function is similar to strtok_r() defined in POSIX.1.
 *
 * @param s the string to parse, may be NULL
 * @param delim 0-terminated list of token delimiters, must be non-NULL
 * @param saveptr user-provided pointer which points to stored
 * information necessary for av_strtok() to continue scanning the same
 * string. saveptr is updated to point to the next character after the
 * first delimiter found, or to NULL if the string was terminated
 * @return the found token, or NULL when no token is found
 */
char *av_strtok(char *s, const char *delim, char **saveptr);

/**
 * Locale-independent conversion of ASCII isdigit.
 */
int av_isdigit(int c);

/**
 * Locale-independent conversion of ASCII isgraph.
 */
int av_isgraph(int c);

/**
 * Locale-independent conversion of ASCII isspace.
 */
int av_isspace(int c);

/**
 * Locale-independent conversion of ASCII characters to uppercase.
 */
static inline int av_toupper(int c)
{
    if (c >= 'a' && c <= 'z')
        c ^= 0x20;
    return c;
}

/**
 * Locale-independent conversion of ASCII characters to lowercase.
 */
static inline int av_tolower(int c)
{
    if (c >= 'A' && c <= 'Z')
        c ^= 0x20;
    return c;
}

/**
 * Locale-independent conversion of ASCII isxdigit.
 */
int av_isxdigit(int c);

/**
 * Locale-independent case-insensitive compare.
 * @note This means only ASCII-range characters are case-insensitive
 */
int av_strcasecmp(const char *a, const char *b);

/**
 * Locale-independent case-insensitive compare.
 * @note This means only ASCII-range characters are case-insensitive
 */
int av_strncasecmp(const char *a, const char *b, size_t n);


/**
 * Thread safe basename.
 * @param path the path, on DOS both \ and / are considered separators.
 * @return pointer to the basename substring.
 */
const char *av_basename(const char *path);

/**
 * Thread safe dirname.
 * @param path the path, on DOS both \ and / are considered separators.
 * @return the path with the separator replaced by the string terminator or ".".
 * @note the function may change the input string.
 */
const char *av_dirname(char *path);

enum AVEscapeMode {
    AV_ESCAPE_MODE_AUTO,      ///< Use auto-selected escaping mode.
    AV_ESCAPE_MODE_BACKSLASH, ///< Use backslash escaping.
    AV_ESCAPE_MODE_QUOTE,     ///< Use single-quote escaping.
};

/**
 * Consider spaces special and escape them even in the middle of the
 * string.
 *
 * This is equivalent to adding the whitespace characters to the special
 * characters lists, except it is guaranteed to use the exact same list
 * of whitespace characters as the rest of libavutil.
 */
#define AV_ESCAPE_FLAG_WHITESPACE 0x01

/**
 * Escape only specified special characters.
 * Without this flag, escape also any characters that may be considered
 * special by av_get_token(), such as the single quote.
 */
#define AV_ESCAPE_FLAG_STRICT 0x02

/**
 * Escape string in src, and put the escaped string in an allocated
 * string in *dst, which must be freed with av_free().
 *
 * @param dst           pointer where an allocated string is put
 * @param src           string to escape, must be non-NULL
 * @param special_chars string containing the special characters which
 *                      need to be escaped, can be NULL
 * @param mode          escape mode to employ, see AV_ESCAPE_MODE_* macros.
 *                      Any unknown value for mode will be considered equivalent to
 *                      AV_ESCAPE_MODE_BACKSLASH, but this behaviour can change without
 *                      notice.
 * @param flags         flags which control how to escape, see AV_ESCAPE_FLAG_ macros
 * @return the length of the allocated string, or a negative error code in case of error
 * @see av_bprint_escape()
 */
int av_escape(char **dst, const char *src, const char *special_chars,
              enum AVEscapeMode mode, int flags);

/**
 * @}
 */

#endif /* AVUTIL_AVSTRING_H */