PerlMonth: Debugging Perl CGI Scripts

[ Thanks to for this link. ]

“This month, we’re going to dig deeply into my bag of tricks and
learn how to debug a Perl CGI script. All the tips and
techniques here are straightforward; most of them are things you
probably know from your first course in programming-that is, if you
had one! And that just may be your problem: if you are a
self-taught Perl programmer, you may not have received any formal
education in debugging.”

“Our first step: verify that the script is available for
execution. … The next logical step is to verify that the script
compiles cleanly. You should as a matter of course start ALL your
perl scripts this way:

#!/usr/bin/perl -w use
diagnostics;"

“There’s a third line that you may wish to add to your code.

use strict;

I hesitate to push this on anyone because I don’t hold myself to
this standard (which most Perl experts would say reflects poorly on
me, and I have no defense for that). All I’ll say is that you
should try it, until such point as you understand what it does:
then, make up your own mind. Basically, this pragma makes Perl more
like other languages that require you to pre-declare variables. ”

Complete
Story