#php 7.x
<?php if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
echo $ip = $_SERVER['HTTP_CLIENT_IP'];
} elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
echo $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
} else {
echo $ip = $_SERVER['REMOTE_ADDR'];
}
?>