php 获取客户端地址

php getip

function getip(){    //获取真实ip             if ($HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"]){                 return  $HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"];             }elseif($HTTP_SERVER_VARS["HTTP_CLIENT_IP"]){                 return  $HTTP_SERVER_VARS["HTTP_CLIENT_IP"];             }elseif($HTTP_SERVER_VARS["REMOTE_ADDR"]){                 return  $HTTP_SERVER_VARS["REMOTE_ADDR"];             }elseif(getenv("HTTP_X_FORWARDED_FOR")){                 return  getenv("HTTP_X_FORWARDED_FOR");             }elseif(getenv("HTTP_CLIENT_IP")){                 return getenv("HTTP_CLIENT_IP");             }elseif(getenv("REMOTE_ADDR")){                 return  getenv("REMOTE_ADDR");             }else{                 return "Unknown";             }     }