whois query using TCP socket in PHP

query.php

<?php
error_reporting(E_ALL);


echo "connection to whois.twnic.net.tw\n";

$address = gethostbyname('whois.iana.org.');

$fp = @fsockopen($address, 43, $errno, $errstr, 5) or die("Socket Error " . $errno . " - " . $errstr);
stream_set_blocking($fp, true);
echo "socket openned\n";


// whois protocol RFC
// https://www.rfc-editor.org/rfc/rfc3912.txt
echo "sending request ... ";
$query = 'zeroplex.tw' . "\r\n";
fputs($fp, $query);
echo "ok \n";

echo "closing socket ... ";
fclose($fp);
echo "ok\n";

$refer = preg_match('/refer: +([^ ]+)/', $result, $matches);
if (1 === $refer) {
    echo "refer found: ";
    var_dump($matches);
} else {
    echo "--------------- \n";
    echo $result . "\n";
}