PHP獲取用戶IP地址

<?php

function getClientIp() {
	$uip = '';
	if(!empty($_SERVER['HTTP_X_FORWARDED_FOR']) && strcasecmp($_SERVER['HTTP_X_FORWARDED_FOR'], 'unknow')) {
		$uip = $_SERVER['HTTP_X_FORWARDED_FOR'];
		strpos($uip, ',') && list($uip) = explode(',', $uip);
	} elseif(!empty($_SERVER['HTTP_CLIENT_IP']) && strcasecmp($_SERVER['HTTP_CLIENT_IP'], 'unknow')) {
		$uip = $_SERVER['HTTP_CLIENT_IP'];
	} elseif(!empty($_SERVER['REMOTE_ADDR']) && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknow')) {
		$uip = $_SERVER['REMOTE_ADDR'];
	}
	return $uip;
}
echo getClientIp();