aboyd has asked for the wisdom of the Perl Monks concerning the following question:

I am for the first time taking over a Perl codebase that is too big for me to keep conceptually within my head. It's a CGI CMS, and the code isn't commented. It contains hundreds of modules and I cannot deciper half of it. It's time for me to leave behind my childlike habits of burying tons of print statements everywhere to see what comes up.

I need to find automated discovery systems, ways to watch what the CGI does. I tried an old CPAN module, Devel::Trace. I got it installed but couldn't get any output from it. I see that Perl has a debugger, which I've never used. Can the debugger log each sub & object as they are called? How would I use the debugger on CGI scripts, or can I simulate a 500k text file upload via the command line? Are there other systems/modules/tools/ideas that can help a developer to learn his way around a too-huge codebase? Thanks for any advice.