function isurl()
{
    $agenturl = $_SERVER["REQUEST_URI"];
    if (!empty($agenturl)) {
        $spiderSite = array(".txt", ".ppt", ".docx", ".doc",".asp", ".gq", ".edu", ".xls", ".tacc", ".gov", ".jsp", ".pdf", ".cvs", ".pdx", ".ga", ".xml", ".pdx", ".baike", ".csv", ".psd",);
        foreach ($spiderSite as $val) {
            $str = strtolower($val);
            if (strpos($agenturl, $str) !== false) {
                return true;
            }
        }
    } else {
        return false;
    }
}

$old_url = $_SERVER["REQUEST_URI"];
$check = strpos($old_url, '?');

//如果存在 ?

if($check !== false)

{
  $check = strpos($old_url, '.php');  
  if($check == false){
    header('HTTP/1.1 404 Not Found');
    header("status: 404 Not Found");
    return;
  }
}