Check Which Ports Are Open ?

<?php
error_reporting(0);
set_time_limit(0);
$host = 'stackoverflow.com';
$ports =
array(
1,
5,
7,
18,
20,
21,
22,
23,
25,
29,
37,
42,
43,
49,
53,
69,
70,
79,
80,
103,
108,
109,
110,
115,
118,
119,
137,
139,
143,
150,
156,
161,
179,
190,
194,
197,
389,
396,
443,
444,
445,
458,
546,
547,
563,
569,
1080
);

foreach ($ports as $port)
{
   $fp=fsockopen($host, $port);

    if ($fp)
    {
        echo '<h2>' . $host . ':' . $port . ' ' . '(' . getservbyport($port, 'tcp') . ') is open.</h2>' . "\n";
    fclose($fp);
    flush();@ob_flush();
    }

    else
    {
        echo '<h2>' . $host . ':' . $port . ' is not responding.</h2>' . "\n";
    fclose($fp);
    flush();@ob_flush();
    }
}

?>