Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
Sure, I'll try my best. :)

Here's what I did originally:

$| = 1; # Don't buffer output print "\e[H\e[J\n"; # Clear the screen $S='|'; japh('82>2 ^7 22>5'); # 'J' japh('88^4 59>4 48/^2 812^6 29>2 />1'); # 'A' japh('815^4 515>4 415/^3 419^2 216>2 />1'); # 'P' japh('822^4 522>4 422/^3 825^7'); # 'H print "\e[24H"; # Jump to line 24 exit; # # This subroutine prints each letter of the word "JAPH" # It writes the words bottom-up, since going top-down # overwrites part of the letters that ultimately have to # be hidden by the sides. # sub japh { my $s = pop; $s =~ s/\s//g; while($s) { $s =~ s/^(\d)(\d+)// and ($y,$x) = ($1,$2); $s =~ s|^/|| and $S = $&; $s =~ s/^([>^])(\d)// and map { block($1) } (1..$2); } } # # This subroutine draws a single block, based on # the current values of the ($X, $Y) coordinates. # sub block { $s = "___ / /|/__/ || | $S|__|/"; $S = '|'; ($X, $Y, $Z) = (3*$x, 2*$y, 0); while ($b = substr($s,0,$Z+++4,"")) { print "\e[".$Y++.";$X"."H$b"; $Z>2? $Z=2: --$X; } select$d,$e,$f,.1; $_[0] eq '^'? $y--: $x++; } __END__ Commands: *YX go to coordinates (Y,X) / set symbol $S to '/' (normally '|') >N move/draw N pixels (right) ^N move/draw N pixels (up) 81>2^721>5 88^4811^75 '815^4515>4515/^3216>3'); # 'P' 822^4 522>4 422/^3 825^7

It's got some notes at the end, and I've added more comments to it just now, but it's essentially the same functionality as the final obfuscation with slightly differently formatted letters (the "H" got wider in the final version), and there wasn't any color added yet.

Note that the reason it's drawn bottom-up is because to-down would obscure parts of the characters that have to be in "front", but would be overwritten by the sides that themselves need to be obscured. The easiest way to achieve this was to cheat and do it bottom-up.

In contrast, here's the obfuscated version which has been fairly de-obfuscated:

eval( q{ $| = print"\e[2J\n"; $k = '|'; s,,2220;3500731;3522735071;1600715074;1622713,; y;0-4;8|_/%;; s;5;\e[103m;g; s,6,\e[102m,g; s;7;\e[m;g; $/ = $_; $_ = q|hb2Gbb5hhDei4dh0BhlFbi201hoC4do0CdsBbp201hvDev5dv0ChzG| +; s;[1-9];>$&;g; s;[A-I];^$&;g; y|A-I|1-9|; { s;^(\w)(\w);; ? ($y = -97 + ord $1, $x = -97 + ord $2): s,^0,, ? $k = '/': s,^([>^])(\d),, ? map { $c = $1; $X = 1 + 3 * $x; $Y = $y * 2; $Z = 4; $" = $/ =~ s;%;$k;r; map { print "\e[${\$Y++};${X}H$_"; $X-- if + ++$Z < 7 } split ';', $"; $k = '|'; select $J,$a,$p,$ARGV[0] || .1; '^' eq $c? $y--: $x++ } 1..$2: last; redo } } =~ y/8 \n/ /dr ); die "\e[22H\n" # ANSI Escape sequence -- jumps to line 22

There's a lot of standard "tricks" going on here, like using special variables in place of regular ones (such as $/ and $", and assigning $| to the print command, which simply turns off buffered output. And using $_ lets me do regex substitutions without the =~ operator, to keep the code size down.

The redo command jumps back to reenter the large { ... } block, also with a minimum of chars. And chaining four ternary operators (...) ? (...) : (...) together makes it even harder to read.

Anywhere you see \e[NNNm, you know it's doing something with Ansi colors -- 103 is yellow, 102 is green, and \e[m turns the color off.

The sequence         s,,2220;3500731;3522735071;1600715074;1622713,; constructs an encoded value into $_ "out of thin air". Then if you add some debugging:

$_ = q|hb2Gbb5hhDei4dh0BhlFbi201hoC4do0CdsBbp201hvDev5dv0ChzG| +; print "Debug: $_\n"; s;[1-9];>$&;g; print "Debug: $_\n"; s;[A-I];^$&;g; print "Debug: $_\n"; y|A-I|1-9|; print "Debug: $_\n";
you can see how the encoded string is converted back a set of commands:
Debug: hb2Gbb5hhDei4dh0BhlFbi201hoC4do0CdsBbp201hvDev5dv0ChzG Debug: hb>2Gbb>5hhDei>4dh0BhlFbi>20>1hoC>4do0CdsBbp>20>1hvDev>5dv0Chz +G Debug: hb>2^Gbb>5hh^Dei>4dh0^Bhl^Fbi>20>1ho^C>4do0^Cds^Bbp>20>1hv^Dev +>5dv0^Chz^G Debug: hb>2^7bb>5hh^4ei>4dh0^2hl^6bi>20>1ho^3>4do0^3ds^2bp>20>1hv^4ev +>5dv0^3hz^7

which still need to get parsed, but are a lot closer to the original sequence in the original program.

I hope that answers some of your curiosity about the obfuscation.

If you have any further questions don't hesitate to ask. And thanks for your interest! :D

say  substr+lc crypt(qw $i3 SI$),4,5

In reply to Re^2: Self-constructing Japh by golux
in thread Self-constructing Japh by golux

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    NodeReaper eats a grue

    How do I use this? | Other CB clients
    Other Users?
    Others browsing the Monastery: (6)
    As of 2017-10-21 16:04 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      My fridge is mostly full of:

















      Results (270 votes). Check out past polls.

      Notices?