fam.php

<?php
$ip = $_POST["ip"];
if ($ip) {
	// super fancy regex check!
	if (preg_match('/^(([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])/',$ip)) {
		exec('ping -c 1 '.$ip, $cmd_result);
		foreach($cmd_result as $str){
			if (strpos($str, '100% packet loss') !== false){
				printf("<h3>Target is NOT alive.</h3>");
				break;
			} else if (strpos($str, ', 0% packet loss') !== false){
				printf("<h3>Target is alive.</h3>");
				break;
			}
		}
	} else {
		echo "Wrong IP Format.";
	}
}
?>