Validating all php generated html code?

Hello ruby team.
I got a new interesting assignment, to validate all html code of all our
products. Doing this manual would take me a very long time. Thus I seek an
automated solution and wonder if anybody has done something similar? Here is
what I think needs to be done:
1. Generate each html page possible (the html code is created by MySQL and
php scripts). It would be great to have a web crawler clicking each link at
the web-site and saving the generated html-file.
2. Validating all the html files
Has anybody done something like this? Any ideas regarding what tools to use?
Any recommendations, ideas, etc?
Thanks for your help.
Bernd