<!doctype html>
<html>
<body>
<form action="/" method="POST">
Domain Name
<input type="text" name="domain_name">
<input type="submit" value="nslookup">
</form>
</body>
</html>
<?php
function is_domain($domain)
{
//domain, sub domain, top level domain
return preg_match(\'/^ (?: [a-z0-9] (?:[a-z0-9\\-]* [a-z0-9])? \\. )*[a-z0-9] (?:[a-z0-9\\-]* [a-z0-9])?\\.[a-z]{2,6}$/ix\', $domain);
}
if(isset($_POST["domain_name"]) && is_domain($_POST["domain_name"]))
{
system("nslookup " . $_POST["domain_name"]);
}
?>