/**  +----------------------------------------------------------  * 检查字符串是否是UTF8编码  +----------------------------------------------------------  * @param string $string 字符串  +----------------------------------------------------------  * @return Boolean  +---------------------------------------------------------- */ function is_utf8($string) {
        return preg_match('%^(?:          [\x09\x0A\x0D\x20-\x7E]            # ASCII        | [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte        |  \xE0[\xA0-\xBF][\x80-\xBF]        # excluding overlongs        | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte        |  \xED[\x80-\x9F][\x80-\xBF]        # excluding surrogates        |  \xF0[\x90-\xBF][\x80-\xBF]{2}     # planes 1-3        | [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15        |  \xF4[\x80-\x8F][\x80-\xBF]{2}     # plane 16    )*$%xs', $string); }