gistfile1.php

<?php

namespace React\Whois;

use Promise\Deferred as Deferred;
use React\Curry\Util as Curry;
use React\Dns\Resolver\Resolver;

class Client
{
    private $dns;
    private $connFactory;

    public function __construct(Resolver $dns, $connFactory)
    {
        $this->dns = $dns;
        $this->connFactory = $connFactory;
    }

    public function query($domain, $callback = null)
    {
        return $this
            ->resolveWhoisServer($domain)
            ->then(Curry::bind(array($this, 'queryWhoisServer'), $domain))
            ->then(function ($result) use ($callback) {
                if (is_callable($callback)) {
                    call_user_func($callback, $result);
                }

                return $result;
            });
    }

    public function resolveWhoisServer($domain)
    {
        $deferred = new Deferred();

        $tld = substr(strrchr($domain, '.'), 1);
        $target = $tld.'.whois-servers.net';

        $this->dns->resolve($target, array($deferred, 'resolve'));

        return $deferred->promise();
    }

    public function queryWhoisServer($domain, $ip)
    {
        $deferred = new Deferred();

        $result = '';

        $conn = call_user_func($this->connFactory, $ip);
        $conn->write("$domain\r\n");
        $conn->on('data', function ($data) use (&$result) {
            $result .= $data;
        });
        $conn->on('close', array($deferred, 'resolve'));

        return $deferred
            ->promise()
            ->then(function ($result) {
                return str_replace("\r\n", "\n", $result);
            });
    }
}