|Perl: the Markov chain saw|
Re: Fun With Reserved Keywordsby Chady (Priest)
|on Sep 11, 2003 at 09:17 UTC||Need Help??|
This is a really cool obfu. and it's the first time I attempt to crack an obfuscation. Please correct me where I'm wrong(spoilers in readmore)
First of all, this obfu uses a lot of quoting, and the xors are there to seperate the statements, so if we hunt down the qw// q// qq// s/// we end up with something that looks like this.
Line 1 : decorative?
Lines 2-4 : These lines evaluate the statement in line 3 - length uc ord returns a true values so that and gets to the print which prints out the first letter of the quoted words 'join use sub tied'. ord return the ord of the first letter, and then chr passes that letter to print. So these lines print 'just'
Lines 6-7 : These lines use the same technique to print 'another' using a small variation.
Lines 10-11 : print 'perl'
Lines 13-15 : print 'hacker' in another variation
The smart thing is the way the last part (lines 10-16) are compiled to be executed in that order; depending on the return values, these last lines evaluate to roughly 0 or 1 and 0 gt 0, and having the statements inside evals makes sure they are executed in order.
I hope I got it right?
He who asks will be a fool for five minutes, but he who doesn't ask will remain a fool for life.
Chady | http://chady.net/