i want to disallow Robots what i need to write quoted bellow is fine? also it ll be take effect to subdomains or not? because i can see them as directory in main domain
An additional way to stop your content from being indexed is to use meta tags. You need to place the following tag in the <head> section of your pages. <META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW"> That's just a little more security against indexing. I like to use both.
As long as you have that in all your top-level directories most reputable crawlers will ignore your site.