"Okay, I removed the colors."

But you have failed to add an Update: indicating this change. Please reread "How do I change/delete my post?" which will explain that to you; in particular, note the It is uncool to update a node in a way that renders replies confusing or meaningless section. I recall we had this discussion last month: "Re^2: Error handling in a module".

"To make it work, I added a dummy file into the lib directory of perl called warnings.pm ..."

So, your code relies on this addition of a "dummy" pragmatic module; however, your post still retains the statement "... it does not rely on any Perl modules ..." which you should correct.

I suggest you look at $^W which was available in Perl 5.004 (see https://metacpan.org/release/CHIPS/perl5.004/view/pod/perlvar.pod#$^W).

If you are going to present code to run on ancient versions of Perl — 5.004 was released 26 years ago; see perlhist — please state that clearly near the start of your post. As it stands, you have to scroll through an entire screenful of comments to find 'use 5.004;'.

Please reread "Writeup Formatting Tips"; this time paying attention to the Use <readmore> tags in long posts section. The code you posted takes up 14 screenfuls on my 27" monitor; probably many more for those with smaller devices. Please be considerate of your fellow monks.