path: root/libavutil/avstring.h

/*
 * Copyright (c) 2007 Mans Rullgard
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; 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);

/**
 * 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);

/**
 * 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);


/**
 * 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);


/**
 * Match instances of a name in a comma-separated list of 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);

/**
 * @}
 */

#endif /* AVUTIL_AVSTRING_H */