Automated testing of cgi / perl

Hello, I have the following situation:

- Existing site with about 18,000 cgi pages.
- Most pages are data driven (fill out form, submit, get results).
Exact results may change from day to day as data get updated.
- Some static html mixed in
- Many pages require authentication. It is a custom in-house
authentication mechanism, but ultimately it stores a temporary session
ID in a session cookie.

I would like to implement automated testing that will:

- Tell me if anything breaks.
- Tell me if a new installation of the same overall site is working
the same as the original (for an upgrade project).
- Tell me if I break anything during maintenance (regression testing)

Can anyone give me some pointers on this? Tool? Overall approach?
Pitfalls? Any clues appreciated.

Larry

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