PHP获取客户端真实IP

//获取用户真实IP
function getIp() {

if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))

$ip = getenv("HTTP_CLIENT_IP"); else

if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_F ORWARDED_FOR"), "unknown"))

$ip = getenv("HTTP_X_FORWARDED_FOR");
else
if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR") , "unknown"))

$ip = getenv("REMOTE_ADDR"); else

if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_A DDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))

$ip = $_SERVER['REMOTE_ADDR'];
else
$ip = "unknown";
return ($ip);
}

echo getIp();