怎样做页面HTTP状态查询,该如何处理

function curl_file_get_contents($durl){
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $durl);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5);
    curl_setopt($ch, CURLOPT_HEADER, true);
    curl_setopt($ch, CURLOPT_NOBODY, 1);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $r = curl_exec($ch);
    //$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE); 
    return $r;
}