Hi,

I am interested to understand what this guy did, but i am unable to, can someone please break it down to a newbie

I've spent the last several days at work, trying to "take over" some work left behind by a departing colleague. I realized we didn't have some of his bash scripting in ansible or in a repo, so I decided this would be a good opportunity to fix all of those problems. After a little while it became clear his script was a set of functions, run in a loop-within-a-loop to iterate through a bunch of things. In the middle, between these two loops, is a pile of inline *PERL* that runs as a bash function and passes data back and forth in all directions. This Perl generates some dynamic SQL commands each loop.

I hate SQL.

Okay... read the Perl. Now, it's been a long time and a long way since my last string of PERLs, so i didn't really grok 100% what I was reading, but I got the gist of it. Finally figured out the SQL wasn't the problem.

Another day goes by, and I finally figure out his code is self documenting! That was what all the little bits were in the perl I didnt get. PerlPod. So now I can figure this out easy . Run it, read the code, make a change, run it... *boom* what?

Nope.

It took me several more hours and a few beer, and it finally clicked. He was using PerlPod to document out the code he didn't want to run, and commented out the documenting code to run the code he wanted. What looked commented out, wasn't, and what looked like a pile of variables being set, was just a bunch of commentary. He was using a documentation module for *flow control*.

What a Hacker. Holy shit. Blew. My. Mind.

I just got schooled very seriously. It's nice to know I can still improve *that much*, even from where I am.

When PerlPod is used to document something, anything between control codes is not interpreted but treated as commented text. He would comment out the control codes (thus rendering the text interpretable) on the parts meant to run, which would differ between machines.

In reply to Using PerlPod Creatively by samijoseph

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