php 获取IP

<?php
	echo 'your ip is :';

	if (@$_SERVER["HTTP_X_FORWARDED_FOR"])
		$ip = $_SERVER["HTTP_X_FORWARDED_FOR"];
	else if (@$_SERVER["HTTP_CLIENT_IP"])
		$ip = $_SERVER["HTTP_CLIENT_IP"];
	else if (@$_SERVER["REMOTE_ADDR"])
		$ip = $_SERVER["REMOTE_ADDR"];
	else if (@getenv("HTTP_X_FORWARDED_FOR"))
		$ip = getenv("HTTP_X_FORWARDED_FOR");
	else if (@getenv("HTTP_CLIENT_IP"))
		$ip = getenv("HTTP_CLIENT_IP");
	else if (@getenv("REMOTE_ADDR"))
		$ip = getenv("REMOTE_ADDR");
	else
		$ip = "Unknown";

	echo $ip;
	return;
?>