PHP截取中英文字符函数

<?PHP 

    /**

     * 截取中英文字符

     * Enter description here ...

     * @param unkNown_type $str

     * @param unkNown_type $start

     * @param unkNown_type $length

     * @param unkNown_type $charset

     * @param unkNown_type $suffix

     * @return unkNown|string

     */

    public static function csubstr($str,$start=0,$length,$charset="utf-8",$suffix=true)

    {

    if(function_exists("mb_substr"))

    {

    if(mb_strlen($str,$charset) <= $length) return $str;

    $slice = mb_substr($str,$start,$charset);

    } else {

    $re['utf-8']   = "/[x01-x7f]|[xc2-xdf][x80-xbf]|[xe0-xef][x80-xbf]{2}|[xf0-xff][x80-xbf]{3}/";

    $re['gb2312'] = "/[x01-x7f]|[xb0-xf7][xa0-xfe]/";

    $re['gbk']          = "/[x01-x7f]|[x81-xfe][x40-xfe]/";

    $re['big5']          = "/[x01-x7f]|[x81-xfe]([x40-x7e]|xa1-xfe])/";

    preg_match_all($re[$charset],$str,$match);

    if(count($match[0]) <= $length) return $str;

    $slice = join("",array_slice($match[0],$length));

    }

    if($suffix) return $slice."…";

    return $slice;

    }

?>

调用方法：

<?PHP echo  Url::csubstr($title,15);?>