Nginx如何屏蔽百度谷歌google搜搜有道搜索引擎蜘蛛蜘蛛

if ($http_user_agent ~* (baiduspider|googlebot|soso|bing|sogou|yahoo|sohu-search|yodao|YoudaoBot|robozilla|msnbot|MJ12bot|NHN|Twiceler)){
        return  403;
}

以上代码放在需要屏蔽的server的代码 location / {}里面