尽管设置了参数CURLOPT_RETURNTRANSFER，但是为什么curl返回1

Question

这是我保留顶级域名和扩展名的服务器数组

受保护的$ servers = array（

    "com.tr" => "whois.nic.tr",
    "gen.tr" => "whois.nic.tr",
    "web.tr" => "whois.nic.tr",
    "k12.tr" => "whois.nic.tr",
    "org.tr" => "whois.nic.tr"
);

我需要获取whois信息，所以我编写了此函数

function whois($domain,$ext)
{
           $server=$this->servers[$ext];
           $domain=$domain.".".$ext;

    if (function_exists('curl_version')) {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_URL, $server);
        curl_setopt($curl, CURLOPT_PORT, 43);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_TIMEOUT, 5);
        curl_setopt($curl, CURLOPT_CUSTOMREQUEST, $domain."\r\n");
        $result = curl_exec($curl);
        curl_close($curl);

                echo '<pre>';
                echo print_r($result);
                echo '</pre>';
    } else {
        trigger_error('cURL is not found!');
        exit();
    }




}

我正在使用这种方式 whois（“ google”，“ com”）;

此功能适用于google.com，它为我提供了正确的域信息，但是当我执行google.org.tr时，（这是很有趣的一部分）有时会重新调整

No match found for "google.org.tr"(whis is expected)

 and  somethimes return "1"

@update

    curl_setopt($curl, CURLOPT_URL, $server);
    curl_setopt($curl, CURLOPT_URL, "telnet://whois.web.tr:43");
    curl_setopt($curl, CURLOPT_PORT, 43);
    curl_setopt($curl, CURLOPT_CUSTOMREQUEST, $domain."\r\n");
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, TRUE);
    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, TRUE);
    curl_setopt($curl, CURLOPT_NOPROGRESS, TRUE);
    curl_setopt($curl, CURLOPT_PROTOCOLS, CURLPROTO_TELNET);