January 2014
Intermediate to advanced
400 pages
9h 23m
English
Content preview from Mastering Perl, 2nd EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Chapter 3. Perl Debuggers
The standard Perl distribution comes with a debugger, although it’s 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. That’s just the beginning, though. I can write my own debugger or use one of the many debuggers created by other Perl masters.
This chapter isn’t 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, I’m 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
don’t 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. It’s
the common mistakes that seem to be the hardest for me to debug. Learn
from the master: don’t discount strict or
warnings
for even small programs.
Now that I’ve said that, you’re 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 don’t like that, just imagine that I’m running every program
with both strict and
warnings turned on from the command line: ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.