duckstation

avstring.h (14940B)

---

 /*
  * 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 <stdint.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);
 
 /**
  * Get the count of continuous non zero chars starting from the beginning.
  *
  * @param s   the string whose length to count
  * @param len maximum number of characters to check in the string, that
  *            is the maximum value which is returned by the function
  */
 static inline size_t av_strnlen(const char *s, size_t len)
 {
     size_t i;
     for (i = 0; i < len && s[i]; i++)
         ;
     return i;
 }
 
 /**
  * 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);
 
 /**
  * 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.
  */
 static inline av_const int av_isdigit(int c)
 {
     return c >= '0' && c <= '9';
 }
 
 /**
  * Locale-independent conversion of ASCII isgraph.
  */
 static inline av_const int av_isgraph(int c)
 {
     return c > 32 && c < 127;
 }
 
 /**
  * Locale-independent conversion of ASCII isspace.
  */
 static inline av_const int av_isspace(int c)
 {
     return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' ||
            c == '\v';
 }
 
 /**
  * Locale-independent conversion of ASCII characters to uppercase.
  */
 static inline av_const int av_toupper(int c)
 {
     if (c >= 'a' && c <= 'z')
         c ^= 0x20;
     return c;
 }
 
 /**
  * Locale-independent conversion of ASCII characters to lowercase.
  */
 static inline av_const int av_tolower(int c)
 {
     if (c >= 'A' && c <= 'Z')
         c ^= 0x20;
     return c;
 }
 
 /**
  * Locale-independent conversion of ASCII isxdigit.
  */
 static inline av_const int av_isxdigit(int c)
 {
     c = av_tolower(c);
     return av_isdigit(c) || (c >= 'a' && c <= 'f');
 }
 
 /**
  * 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);
 
 /**
  * Locale-independent strings replace.
  * @note This means only ASCII-range characters are replaced.
  */
 char *av_strireplace(const char *str, const char *from, const char *to);
 
 /**
  * Thread safe basename.
  * @param path the string to parse, on DOS both \ and / are considered separators.
  * @return pointer to the basename substring.
  * If path does not contain a slash, the function returns a copy of path.
  * If path is a NULL pointer or points to an empty string, a pointer
  * to a string "." is returned.
  */
 const char *av_basename(const char *path);
 
 /**
  * Thread safe dirname.
  * @param path the string to parse, on DOS both \ and / are considered separators.
  * @return A pointer to a string that's the parent directory of path.
  * If path is a NULL pointer or points to an empty string, a pointer
  * to a string "." is returned.
  * @note the function may modify the contents of the path, so copies should be passed.
  */
 const char *av_dirname(char *path);
 
 /**
  * Match instances of a name in a comma-separated list of names.
  * List entries are checked from the start to the end of the names list,
  * the first match ends further processing. If an entry prefixed with '-'
  * matches, then 0 is returned. The "ALL" list entry is considered to
  * match all names.
  *
  * @param name  Name to look for.
  * @param names List of names.
  * @return 1 on match, 0 otherwise.
  */
 int av_match_name(const char *name, const char *names);
 
 /**
  * Append path component to the existing path.
  * Path separator '/' is placed between when needed.
  * Resulting string have to be freed with av_free().
  * @param path      base path
  * @param component component to be appended
  * @return new path or NULL on error.
  */
 char *av_append_path_component(const char *path, const char *component);
 
 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.
     AV_ESCAPE_MODE_XML,       ///< Use XML non-markup character data 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 (1 << 0)
 
 /**
  * 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 (1 << 1)
 
 /**
  * Within AV_ESCAPE_MODE_XML, additionally escape single quotes for single
  * quoted attributes.
  */
 #define AV_ESCAPE_FLAG_XML_SINGLE_QUOTES (1 << 2)
 
 /**
  * Within AV_ESCAPE_MODE_XML, additionally escape double quotes for double
  * quoted attributes.
  */
 #define AV_ESCAPE_FLAG_XML_DOUBLE_QUOTES (1 << 3)
 
 
 /**
  * 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()
  */
 av_warn_unused_result
 int av_escape(char **dst, const char *src, const char *special_chars,
               enum AVEscapeMode mode, int flags);
 
 #define AV_UTF8_FLAG_ACCEPT_INVALID_BIG_CODES          1 ///< accept codepoints over 0x10FFFF
 #define AV_UTF8_FLAG_ACCEPT_NON_CHARACTERS             2 ///< accept non-characters - 0xFFFE and 0xFFFF
 #define AV_UTF8_FLAG_ACCEPT_SURROGATES                 4 ///< accept UTF-16 surrogates codes
 #define AV_UTF8_FLAG_EXCLUDE_XML_INVALID_CONTROL_CODES 8 ///< exclude control codes not accepted by XML
 
 #define AV_UTF8_FLAG_ACCEPT_ALL \
     AV_UTF8_FLAG_ACCEPT_INVALID_BIG_CODES|AV_UTF8_FLAG_ACCEPT_NON_CHARACTERS|AV_UTF8_FLAG_ACCEPT_SURROGATES
 
 /**
  * Read and decode a single UTF-8 code point (character) from the
  * buffer in *buf, and update *buf to point to the next byte to
  * decode.
  *
  * In case of an invalid byte sequence, the pointer will be updated to
  * the next byte after the invalid sequence and the function will
  * return an error code.
  *
  * Depending on the specified flags, the function will also fail in
  * case the decoded code point does not belong to a valid range.
  *
  * @note For speed-relevant code a carefully implemented use of
  * GET_UTF8() may be preferred.
  *
  * @param codep   pointer used to return the parsed code in case of success.
  *                The value in *codep is set even in case the range check fails.
  * @param bufp    pointer to the address the first byte of the sequence
  *                to decode, updated by the function to point to the
  *                byte next after the decoded sequence
  * @param buf_end pointer to the end of the buffer, points to the next
  *                byte past the last in the buffer. This is used to
  *                avoid buffer overreads (in case of an unfinished
  *                UTF-8 sequence towards the end of the buffer).
  * @param flags   a collection of AV_UTF8_FLAG_* flags
  * @return >= 0 in case a sequence was successfully read, a negative
  * value in case of invalid sequence
  */
 av_warn_unused_result
 int av_utf8_decode(int32_t *codep, const uint8_t **bufp, const uint8_t *buf_end,
                    unsigned int flags);
 
 /**
  * Check if a name is in a list.
  * @returns 0 if not found, or the 1 based index where it has been found in the
  *            list.
  */
 int av_match_list(const char *name, const char *list, char separator);
 
 /**
  * See libc sscanf manual for more information.
  * Locale-independent sscanf implementation.
  */
 int av_sscanf(const char *string, const char *format, ...);
 
 /**
  * @}
  */
 
 #endif /* AVUTIL_AVSTRING_H */