Re: Undocumented Operator Japh

[chargrill]

Clever! liverpole++

Here's a crack at deobfuscating it:

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Update: Cleared up the "obfuscated deobfuscation" as noted by ysth, though the original test was written to most closely resemble (from at least my point of view) the original obfuscated code. Apologies for any confusion. Also added a little extra explanation (with reference to associated documentation).

[liverpole]

Nicely done, chargrill, as always++

One of the fun parts of creating the obfuscation was writing the subroutine to "decrement" a word (eg. "Jus"-- => "Jur").

It wasn't clear initially clear how many "increments" I was going to want to make, and if it turned out to be more than a few (as it certainly did), I needed to a subroutine to do it.

This was what I ended up with:

sub decrement_word {
    my ($pword) = @_;
    my @vals = map { ord $_ } (split //, $$pword);
    my $idx = $#vals;
    while (1) {
        if ($vals[$idx] != ord('a') and $vals[$idx] != ord('A')) {
            --$vals[$idx];
            last;
        }
        if (0 == $idx) {
            shift @vals;
            last;
        }
        $vals[$idx] += 25;
        --$idx;
    }
    my $word = join '', map { chr } @vals;
    $$pword = $word;
}

It's too bad, I think, that a word "decrement" isn't part of the Perl language, at least for the obfuscatory potential it would provide. ;-)

[ysth]

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Please don't obfuscate your deobfuscation.