php获取用户ip

function getip(){
	if (getenv('HTTP_CLIENT_IP'))
	{
		$ip = getenv('HTTP_CLIENT_IP'); //可伪造
	}
	elseif (getenv('HTTP_X_FORWARDED_FOR'))
	{
		$ip = getenv('HTTP_X_FORWARDED_FOR'); //可伪造
	}
	elseif (getenv('HTTP_X_FORWARDED'))
	{
		$ip = getenv('HTTP_X_FORWARDED');
	}
	elseif (getenv('HTTP_FORWARDED_FOR'))
	{
		$ip = getenv('HTTP_FORWARDED_FOR');
	}
	elseif (getenv('HTTP_FORWARDED'))
	{
		$ip = getenv('HTTP_FORWARDED');
	}
	else
	{
		$ip = $_SERVER['REMOTE_ADDR'];
	}
	return $ip;
}

　　php获取用户ip