Each pair in @japh (I reformatted $q into @japh for convenience) encodes two or three pieces of information. Each number is split as a nibble and a byte. If the nibble in the first number is non-zero then the byte from the second number is an offset into $data to find a two byte hex encoded character. If the nibble was zero then each byte specifies an index into $data to retrieve the two nibbles of the two byte hex encoded character. The first number's byte is the most significant nibble in that value.

The de-obfuscated source

#!/usr/bin/perl -w
use strict;

my $c = sub {substr shift(), 0, 2 };
my $d = sub {substr shift(), 0, 1 };
my $f = sub { $_[1] ->( $_[0] ) };
my $data =
    join '',
    map sprintf( '%02x', $_ & 1 ? $_ : 255 - $_ ),
    0 .. 255;

my @japh = (
    [qw[082 15E]],
    [qw[258 0B1]],
    [qw[258 071]],
    [qw[258 091]],
    [qw[042 002]],
    [qw[258 0C2]],
    [qw[124 028]],
    [qw[258 0DE]],
    [qw[258 16F]],
    [qw[0C2 0F0]],
    [qw[258 0CA]],
    [qw[258 051]],
    [qw[1A0 00A]],
    [qw[258 015]],
    [qw[258 134]],
    [qw[258 1AF]],
    [qw[0C2 064]],
    [qw[1A4 1F4]],
    [qw[0D6 116]],
    [qw[258 13C]],
    [qw[258 0C6]],
    [qw[258 0D6]],
    [qw[0C2 1EB]],
    [qw[1F1 1A0]],
    [qw[258 042]],
    [qw[1F4 0A0]]);

while (my $chr = shift @japh) {
    my ($l, $r) = map hex(), @$chr;

    print chr hex
        ($l >= 501
         ? substr($data, $r, 2)
         : substr($data, $l, 1) . substr($data, $r, 1) );
}

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In reply to Re: indirection by diotalevi
in thread indirection by iamcal

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