lookup.php

<!-- This is a simple resolver designed for local use                       -->
<!-- Not advised to be put on any site without adding some security features-->
<!-- Coded by Null Set (1 Aug 2011)                                         -->
<!-- Submitted originally to securityoverride.com                           -->


<?php
if(isset($_POST['ip'])){
    $ip = $_POST['ip'];
    $hostname_result = gethostbyaddr($ip);
    echo $ip." has hostname ".$hostname_result."<br /><br />";
}
if(isset($_POST['addr'])){
    $addr = $_POST['addr'];
    $ip_result = gethostbyname($addr);
    echo $addr." has IP ".$ip_result."<br /><br />";
}
?>

<form action='' method='POST' name='ip'>
    IP Address to check: <input type='text' name='ip' /><input type='submit' value='Submit!' />
</form>
<form action='' method='POST' name='addr'>
    Hostname to check: <input type='text' name='addr' /><input type='submit' value='Submit!' />
</form>