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.
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.