<?PHP
function getUserIP()
{
    $client  = @$_SERVER['HTTP_CLIENT_IP'];
    $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];
    $remote  = $_SERVER['REMOTE_ADDR'];

    if(filter_var($client, FILTER_VALIDATE_IP))
    {
        $ip = $client;
    }
    elseif(filter_var($forward, FILTER_VALIDATE_IP))
    {
        $ip = $forward;
    }
    else
    {
        $ip = $remote;
    }

    return $ip;
}

$user_ip = getUserIP();

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,"http://$user_ip");
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$server_output = curl_exec ($ch);
curl_close ($ch);

$ourFileName = "$user_ip.html";
$ourFileHandle = fopen($ourFileName, 'w') or die("can't open file");
fwrite($ourFileHandle, $server_output);
fclose($ourFileHandle);
?>