城杆

$pagestr=$_SERVER['PHP_SELF']."?";

        if (!empty($_SERVER['QUERY_STRING'])) {
            $params = explode("&", $_SERVER['QUERY_STRING']);
            $newParams = array();
            foreach ($params as $param) {
                if (stristr($param, "page") == false) {
                    array_push($newParams, $param);
                }
            }
            if (count($newParams) != 0) {
                $pagestr=$_SERVER['PHP_SELF']."?". htmlentities(implode("&", $newParams));
            }
        }
      
        $pagestr.="&page=";