PHP获取客户端IP方法改进

PHP获取客户端IP方法改进

function get_client_ip() { 
	if(isset($_SERVER)){
		if(isset($_SERVER['HTTP_X_FORWARDED_FOR'])){
			$realip = $_SERVER['HTTP_X_FORWARDED_FOR'];
		}elseif(isset($_SERVER['HTTP_CLIENT_IP'])){
			$realip = $_SERVER['HTTP_CLIENT_IP'];
		}else{
			$realip = $_SERVER['REMOTE_ADDR'];
		}
	}else{
		if(getenv("HTTP_X_FORWARDED_FOR")){
			$realip = getenv( "HTTP_X_FORWARDED_FOR");
		}elseif (getenv("HTTP_CLIENT_IP")){
			$realip = getenv("HTTP_CLIENT_IP");
		}else{
			$realip = getenv("REMOTE_ADDR");
		}
	}
	$arr = explode(",",trim($realip));
	foreach($arr as $o){
		if(preg_match("/^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/",$o)){
			return $o;
		}
	}
	return "unknown";
}