php实现escape和Unescape方法

function escape($str) {

    preg_match_all("/[\x80-\xff].|[\x01-\x7f]+/",$str,$r);

    $ar = $r[0];

    foreach($ar as $k=>$v) {

        if(ord($v[0]) < 128)

            $ar[$k] = rawurlencode($v);

        else

            $ar[$k] = "%u".bin2hex(iconv("GB2312","UCS-2",$v));

    }

    return join("",$ar);

}

function Un_escape($str) {

    $str = rawurldecode($str); 

    preg_match_all("/(?:%u.{4})|.+/",$str,$r);

    $ar = $r[0];

    foreach($ar as $k=>$v) {

        if(substr($v,0,2) == "%u" && strlen($v) == 6) 

$ar[$k] = iconv("UCS-2","GB2312",pack("H4",substr($v,-4)));

    }

    return join("",$ar);

}