Chapter 3. Perl Debuggers
The standard Perl distribution comes with a debugger, although itâs really just another Perl program, perl5db.pl. Since it is just a program, I can use it as the basis for writing my own debuggers to suit my needs, or I can use the interface perl5db.pl provides to configure its actions. Thatâs just the beginning, though. I can write my own debugger or use one of the many debuggers created by other Perl masters.
This chapter isnât about actually debugging Perl source code to find problems; people have written entire books about that. The more you practice Perl, the better you should get at that.
Before You Waste Too Much Time
Before I get started, Iâm almost required to remind you that Perl offers two huge
debugging aids: strict
and warnings
. I have the most trouble with smaller programs where I
donât think I need strict
and I
make the stupid mistakes it would have caught. I spend much more time than
I should tracking down something Perl would have shown me instantly. Itâs
the common mistakes that seem to be the hardest for me to debug. Learn
from the master: donât discount strict
or
warnings
for even small programs.
Now that Iâve said that, youâre going to look for it in the examples
in this chapter. Just pretend those lines are there, and the book costs a
bit less for the extra half a page that I saved by omitting those lines.
Or, if you donât like that, just imagine that Iâm running every program
with both strict
and
warnings
turned ...
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