Tp框架获取客户端IP地址

 /**
  * 获取客户端IP地址
  * @param integer $type 返回类型 0 返回IP地址 1 返回IPV4地址数字
  * @return mixed
  */
 function get_client_ip($type = 0) {
     $type       =  $type ? 1 : 0;
     static $ip  =   NULL;
     if ($ip !== NULL) return $ip[$type];
     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'];
     }
     // IP地址合法验证
     $long = sprintf("%u",ip2long($ip));
     $ip   = $long ? array($ip, $long) : array('0.0.0.0', 0);
     return $ip[$type];
 }