PHP取得用户真实IP

　　function getIp() {　　if($_SERVER['HTTP_CLIENT_IP']) {　　$ip = $_SERVER['HTTP_CLIENT_IP'];　　} elseif ($_SERVER['HTTP_X_FORWARDED_FOR']) {　　$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];　　} else {　　$ip = $_SERVER['REMOTE_ADDR'];　　}　　}