API PHP IP-TUNNEL di Ubuntu 18.04 x64

<?php

$ipaddr = $_GET['ip'];

$update = shell_exec("sudo ip tunnel change ipip0 remote $ipaddr");

$file= fopen("ip.txt","w");

fputs($file, $ipaddr);

fclose($file);

$lastip = file_get_contents("ip.txt");

echo '<pre>IP Update: '.$lastip.'</pre>';