function check($host) {
$server = 'whois.tcinet.ru';
$socket = fsockopen($server, 43);
if ($socket) {
fputs($socket, $host . PHP_EOL);
$text = '';
while (!feof($socket)) {
$text .= fgets($socket, 128);
}
fclose($socket);
echo $text;
}
}
<pre><?=check('domen.ru')?></pre>