How store only home page of domains but crawl all the pages to detect all different domains

[Asier Martínez]

Hi to all,
here is my problem. I want to crawl "all" ( to certain depth limit,
you know ) the pages of certain domains/subdomains to detect them, but
only store the home pages of the domains.( I don't have the list of
the domains )
¿There is a easy way to do this? or I have to change the source code
of some plugin? where can I start to looking?

Thanks in advance,