获取客户端IP

get_client_ip

public static function get_client_ip($type=0,$adv=false){
		$type=$type?1:0;
		static $ip=null;
		if($ip!==null){
			return $ip[$type];
		}
		if($adv){
			if(isset($_SERVER['HTTP_X_FORWARDED_FOR'])){
				$arr=explode(',',$_SERVER['HTTP_X_FORWARDED_FOR']);
				$pos=array_search('unknown',$arr);
				if(false!==$pos){
					unset($arr[$pos]);
				}
				$ip=trim($arr[0]);
			}elseif(isset($_SERVER['HTTP_CLIENT_IP'])){
				$ip=$_SERVER['HTTP_CLIENT_IP'];
			}elseif(isset($_SERVER['REMOTE_ADDR'])){
				$ip=$_SERVER['REMOTE_ADDR'];
			}
		}elseif(isset($_SERVER['REMOTE_ADDR'])){
			$ip=$_SERVER['REMOTE_ADDR'];
		}
		// IP地址合法验证
		$long=sprintf("%u",ip2long($ip));
		$ip=$long?[
			$ip,
			$long
		]:[
			'0.0.0.0',
			0
		];
		return $ip[$type];
	}