thinkphp之获取客户端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];}