22
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Classic code golf challenge. Write the most obscure Perl program to print "Just another Perl hacker". Here's the Wikipedia article on it. Bonus points if it fits in 3 lines / 70 characters each.

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  • 2
    \$\begingroup\$ Obfuscated instead of obscure? \$\endgroup\$ – Josh Jan 27 '11 at 21:00
  • 13
    \$\begingroup\$ Code golf has to be about shortest code, not "most obscure". Shortest is objective. "Most obscure" is subjective. \$\endgroup\$ – Chris Jester-Young Jan 27 '11 at 21:00
  • 2
    \$\begingroup\$ @Chris: Wasn't this also about general programming puzzles? Ok, arguable whether obfuscation falls under that but as far as I understood it this wasn't a pure code golf site. \$\endgroup\$ – Joey Jan 27 '11 at 21:15
  • 1
    \$\begingroup\$ @Joey: It's not, but, the Stack Exchange platform is much more effective for objective questions, not ones "that the OP likes best". \$\endgroup\$ – Chris Jester-Young Jan 27 '11 at 21:18
8
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@H=@h=(176,138,140,17,87,54,126,182,217,223,136,130,136,117,73,52,154,
134,161,36,33,92,60,51);for(;$j<24;$j++){$x=0;for($k=0;$k<24;$k++){$x
+=@h[$k]<<($j*$k%24);$x%=241;}@H[$j]=$x;}print pack('c*',@H)

I'm not sure whether a newline at the end is required: if so, the addition of ."\n" still doesn't take me up to the limit of 3 lines * 70 chars/line.

If it weren't for encoding issues the initialisation could be much smaller and extracted with unpack, so I expect someone can improve on this. I'm thinking about making a more efficient version - this is O(n^2), and O(n lg n) decoding is possible.

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  • \$\begingroup\$ +1 for <3 at the end of character value of your array! \$\endgroup\$ – Ry- Apr 28 '11 at 19:53
28
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eval eval '"'.


                                      ('['^"\+").(
           ('[')^                   ')').('`'|')').
        ('`'|'.').                ('['^'/').('{'^'['
 ).'\\'.'"'  .('`'^              '*').('['^'.').('['^
'(').('['^'/').('{'^            '[').('`'|'!').(('`')|
'.').('`'|'/').("\["^          '/').('`'|'(').('`'|'%'
  ).('['^')').(('{')^        '[').('{'^'+').('`'|'%').(
       '['^')').('`'|      ',').('{'^'[').('`'|'(').('`'
      |'!').('`'|'#'     ).('`'|'+').('`'|'%').('['^')').
     '\\'.'"'.("\!"^   '+').'"';$:='.'^'~';$~='@'|"\(";$^=
    ')'^'[';$/='`'|   '.';$,='('^'}';$\='`'|'!';$:=')'^"\}";
    $~='*'|"\`";$^=  '+'^'_';$/='&'|'@';$,='['&'~';$\=','^'|'
    ;$:='.'^'~';$~  ='@'|'(';$^=')'^'[';$/='`'|'.';$,='('^'}'
    ;$\='`'|'!';$:  =')'^'}';$~='*'|'`';$^='+'^'_';$/='&'|'@';
    $,='['&'~';$\=','^'|';$:='.'^'~';$~='@'|'(';$^=')'^'[';$/=
    '`'|'.';$,='('^'}';$\='`'|'!';$:=')'^'}';$~='*'|'`';$^='+'^
     '_';$/='&'|'@';$,='['&'~';$\=','^'|';$:='.'^'~';$~='@'|'('
     ;$^=')'^'[';$/='`'|'.';$,='('^'}';$\='`'|'!';$:=')'^'}';$~=
      '*'|'`';$^='+'^'_';$/='&'|'@';$,='['&'~';$\=','^'|';$:='.'^
       '~';$~='@'|'(';$^=')'^'[';$/='`'|'.';$,='('^'}';$\='`'|'!'
        ;$:=')'^'}';$~='*'|'`';$^='+'^'_';$/='&'|'@';$,="\["& '~'
         ;$\=','^'|';$:='.'^'~';$~='@'|'(';$^=')'^'[';$/='`'  |((
          '.'));$,='('^'}';$\='`'|'!';$:=')'^'}';$~ ='*'|'`'  ;$^
            ='+'^'_';$/='&'|'@';$,='['&'~';$\=','^  '|';$:=   '.'
             ^'~'; $~='@'|'(';$^=')'^'[';$/="\`"|   '.';$,=   '('
                   ^'}';$\='`'|'!';$:=')'^'}';$~    =('*')|   '`'
                   ;$^='+'^    '_';$/='&' |"\@";     $,='['   &+
                   '~';$\=     ','^'|';   $:='.'     ^"\~";  $~
                   =('@')|     "\(";$^=   "\)"^       "\[";  (
                   ($/))=      '`'|'.';   ($,)         ='('
                   ^"\}";     $\=('`')|   '!';         ($:)
                    =')'^     "\}";$~=    '*'|         '`';
                    ($^)=     '+'^'_'     ;$/=         '&'|
                    '@';     $,='['       &'~'         ;$\=
                    ','^     '|'          ;$:=         '.'^
                    '~';      $~=         '@'          |((
                    '('        ));       $^=           ')'
                    ^((         '['     ));            $/=
                    '`'          |((   '.'              ))
                    ;(             ($,))=               ((
                    ((              '('))               ))
                    ^+             "\}";$\=             ((
                   '`'            ))|+ "\!";            $:
                  =((           ')'))^  '}';           $~=
                 '*'|         "\`";$^=   '+'          ^'_'
               ;($/)=                                ('&')|
             "\@";$,=                               '['&'~'
\$\endgroup\$
5
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use Time'HiRes"usleep";$|=@q=(a..z,' ');@w=('just another perl hacker'
=~/./g);while("@w"ne"@e"){$e[$_]eq$w[$_]or$e[$_]=$q[rand@q]for+0..$#w;
print"\r@e";usleep+1e5}

animated version :)

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3
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Less than 70 character on 3 lines:

$_=unpack("H21","9Ø
HvÂláµöÂ");s/(.)/" "x(hex$1<3).substr
"AHPJocehtunarslk",hex$1,1/eg;say

Care: It's ISO-8859-1 encoded.

perl -E '$_=unpack("H21","9Ø
HvÂláµöÂ");s/(.)/" "x(hex$1<3).substr
"AHPJocehtunarslk",hex$1,1/eg;say'

Just Another Perl Hacker 

More than 70 chars at all, but less than 100!

wc -clL <<< '$_=unpack("H21","9Ø
HvÂláµöÂ");s/(.)/" "x(hex$1<3).substr
"AHPJocehtunarslk",hex$1,1/eg;say'

  3 92  37

And a little obfuscated!

A little away?!

There is a <1'000 perl script with a full help and some features:

(It's ISO-8859-1 encoded too ;)

#!/usr/bin/perl -s
$;=$/;$_=q=sub'O{un=."\144e".q[f}sub'l{$#_==-1?leng].q[th:leng].'t'.q[h&a}sub'u{($.=
q;?02:;)=~y+0-@+a-q+;$. =~s/^/&a?"un].q[":""/mxe;$..=' "b';$..=do{$.].q[=~m+^u+?&a:1
}<<3;$..='","';$..=do{$.].q[=~m+^u+?"\44_":&a};eval $.."\42"}s].q[ub'a{pop}sub'b{$.=
"Hauri Félix, ";$v?do{$_=$.;y+?-^+_-~+;].q[s/\s.*/.ch/mgx;$_=do{$0=~m-j\w+-?$&.q.@.:
(q.w.x3).q,.,}.q qf-q].q[.$_;$..$_}:sub].q[str("lockpents ".$.,&a,1)}sub'p{pr]."in".
q<t do{$#_+1?&a."\n":do{/\n/?$_:$_.".\n"}}};sub'x{e>.pack("v",27000).q<t}sub't{sel>.
"ec".q<t O,&O,O,&a};$v&&{p $0." \251".(30*67)." ".b}&&x;$j&&do{$_="Îx¹\26§ÕIÕ\220º".
"2Õ";$_=>.q<u 12,1;s/.{4}/b ord u O,"$&",O/meg;tr+@-[+`-{+;s/./($.=$&)=~y.^-{.?-\\>.
q<\\.;$./xe;p;$c&&do{$c!=1&&do{$_=$c." ";p};fo>."reac".q<h$=(1..2*l){s/.//m;$_.=$&;p
"\33[A\r".$_;t.1}};x};$/=O;o>.chr(0x38*2).q-en$_,$0;$_=<$_>;$k&&p&&x||$p&&do{p;op-.q
len$p,$p;p<$p>;x};$h&&do{$_="Usal.q lge: ".$0." [ -v | -h | -j [-c[=string]] | -k |l
.q+ -p=file.pl ]";p;x};1+;eval||die+No.$;;

There are some features:

./japh.pl -h
Usage: ./japh.pl [ -v | -h | -j [-c[=string]] | -k | -p=file.pl ].

Where:

  • -v signature
  • -h help string
  • -j prompt Just another perl hacker.
  • -c animate the japh string or a submited string if any
  • -k dump the script himself
  • -p polute another script

So:

./japh.pl -j
Just another perl hacker.

./japh.pl -k | wc -lcL
     14     998      84

./japh.pl -p=$(which perldoc) >japhedPerldoc
chmod +x japhedPerldoc 

./japhedPerldoc perl | head
PERL(1)               User Contributed Perl Documentation              PERL(1)

NAME
   perl - The Perl 5 language interpreter

SYNOPSIS
       perl [ -sTtuUWX ]      [ -hv ] [ -V[:configvar] ]
            [ -cw ] [ -d[t][:debugger] ] [ -D[number/list] ]

./japhedPerldoc -j -c
Just another perl hacker.

(The last string is animated:)

Trying to de-obfucate

There is a nice B::Deparse module available on CPAN:

perl -MO=Deparse japh.pl    
$; = $/;
$_ = qq[sub'O{undef}sub'l{\$#_==-1?length:length&a}sub'u{(\$.=\nq;?02:;)=~y+0-\@+a-q+;\$. =~s/^/&a?"un":""/mxe;\$..=' "b';\$..=do{\$.=~m+^u+?&a:1\n}<<3;\$..='","';\$..=do{\$.=~m+^u+?"\\44_":&a};eval\$.."\\42"}sub'a{pop}sub'b{\$.=\n"Hauri F\351lix, ";\$v?do{\$_=\$.;y+?-^+_-~+;s/\\s.*/.ch/mgx;\$_=do{\$0=~m-j\\w+-?\$&.q.\@.:\n(q.w.x3).q,.,}.q qf-q.\$_;\$..\$_}:substr("lockpents ".\$.,&a,1)}sub'p{print do{\$#_+1?&a."\\n":do{/\\n/?\$_:\$_.".\\n"}}};sub'x{e] . pack('v', 27000) . q[t}sub't{sel] . 'ec' . qq[t O,&O,O,&a};\$v&&{p \$0." \\251".(30*67)." ".b}&&x;\$j&&do{\$_="\316x\271\\26\247\325I\325\\220\272".\n"2\325";\$_=] . 'u 12,1;s/.{4}/b ord u O,"$&",O/meg;tr+@-[+`-{+;s/./($.=$&)=~y.^-{.?-\\' . '\\.;$./xe;p;$c&&do{$c!=1&&do{$_=$c." ";p};fo' . 'reac' . qq(h\$=(1..2*l){s/.//m;\$_.=\$&;p\n"\\33[A\\r".\$_;t.1}};x};\$/=O;o) . 'p' . 'en$_,$0;$_=<$_>;$k&&p&&x||$p&&do{p;op' . 'en$p,$p;p<$p>;x};$h&&do{$_="Usa' . 'ge: ".$0." [ -v | -h | -j [-c[=string]] | -k |' . ' -p=file.pl ]";p;x};1';
die 'No' . $; unless eval $_;
japh.pl syntax OK

Well, this is more readable, but...

Ok, there is a pack('v', 27000), what it mean:

perl -E "say pack('v', 27000)";
xi

Hmm. so we could try to simplify deparser's work:

perl -MO=Deparse <(sed -e <japh.pl 's/pack("v",27000)/"xi"/')
$; = $/;
$_ = qq(sub'O{undef}sub'l{\$#_==-1?length:length&a}sub'u{(\$.=\nq;?02:;)=~y+0-\@+a-q+;\$. =~s/^/&a?"un":""/mxe;\$..=' "b';\$..=do{\$.=~m+^u+?&a:1\n}<<3;\$..='","';\$..=do{\$.=~m+^u+?"\\44_":&a};eval \$.."\\42"}sub'a{pop}sub'b{\$.=\n"Hauri F\351lix, ";\$v?do{\$_=\$.;y+?-^+_-~+;s/\\s.*/.ch/mgx;\$_=do{\$0=~m-j\\w+-?\$&.q.\@.:\n(q.w.x3).q,.,}.q qf-q.\$_;\$..\$_}:substr("lockpents ".\$.,&a,1)}sub'p{print do{\$#_+1?&a."\\n":do{/\\n/?\$_:\$_.".\\n"}}};sub'x{exit}sub't{select O,&O,O,&a};\$v&&{p \$0." \\251".(30*67)." ".b}&&x;\$j&&do{\$_="\316x\271\\26\247\325I\325\\220\272".\n"2\325";\$_=u 12,1;s/.{4}/b ord u O,"\$&",O/meg;tr+\@-[+`-{+;s/./(\$.=\$&)=~y.^-{.?-\\\\.;\$./xe;p;\$c&&do{\$c!=1&&do{\$_=\$c." ";p};foreach\$=(1..2*l){s/.//m;\$_.=\$&;p\n"\\33[A\\r".\$_;t.1}};x};\$/=O;open\$_,\$0;\$_=<\$_>;\$k&&p&&x||\$p&&do{p;open\$p,\$p;p<\$p>;x};\$h&&do{\$_="Usage: ".\$0." [ -v | -h | -j [-c[=string]] | -k | -p=file.pl ]";p;x};1);
die 'No' . $; unless eval $_;
/dev/fd/63 syntax OK

Well, now it is clear that whole script is contained in qq(...) on line 2 and have to be submited to eval. We could now:

perl -MO=Deparse <(sed -e <japh.pl 's/pack("v",27000)/"xi"/') |
    sed -ne 's/$_ = \(qq(.*)\);/print \1/p' |
    perl
/dev/fd/63 syntax OK
sub'O{undef}sub'l{$#_==-1?length:length&a}sub'u{($.=
q;?02:;)=~y+0-@+a-q+;$. =~s/^/&a?"un":""/mxe;$..=' "b';$..=do{$.=~m+^u+?&a:1
}<<3;$..='","';$..=do{$.=~m+^u+?"\44_":&a};eval $.."\42"}sub'a{pop}sub'b{$.=
"Hauri Félix, ";$v?do{$_=$.;y+?-^+_-~+;s/\s.*/.ch/mgx;$_=do{$0=~m-j\w+-?$&.q.@.:
(q.w.x3).q,.,}.q qf-q.$_;$..$_}:substr("lockpents ".$.,&a,1)}sub'p{print do{$#_+1?&a."\n":do{/\n/?$_:$_.".\n"}}};sub'x{exit}sub't{select O,&O,O,&a};$v&&{p $0." \251".(30*67)." ".b}&&x;$j&&do{$_="Îx¹\26§ÕIÕ\220º".
"2Õ";$_=u 12,1;s/.{4}/b ord u O,"$&",O/meg;tr+@-[+`-{+;s/./($.=$&)=~y.^-{.?-\\.;$./xe;p;$c&&do{$c!=1&&do{$_=$c." ";p};foreach$=(1..2*l){s/.//m;$_.=$&;p
"\33[A\r".$_;t.1}};x};$/=O;open$_,$0;$_=<$_>;$k&&p&&x||$p&&do{p;open$p,$p;p<$p>;x};$h&&do{$_="Usage: ".$0." [ -v | -h | -j [-c[=string]] | -k | -p=file.pl ]";p;x};1

In the hope deparser could better understand, now:

perl -MO=Deparse <(sed -e <japh.pl 's/pack("v",27000)/"xi"/') |
    sed -ne 's/$_ = \(qq(.*)\);/print \1/p' |
    perl |
    perl -MO=Deparse
/dev/fd/63 syntax OK
sub O {
    undef;
}
sub l {
    $#_ == -1 ? length $_ : length &a;
}
sub u {
    ($. = '?02:') =~ tr/0-@/a-q/;
    $. =~ s/^/&a ? 'un' : '';/emx;
    $. .= ' "b';
    $. .= do {
        $. =~ /^u/ ? &a : 1
    } << 3;
    $. .= '","';
    $. .= do {
        $. =~ /^u/ ? '$_' : &a
    };
    eval $. . '"';
}
sub a {
    pop();
}
sub b {
    $. = "Hauri F\351lix, ";
    $v ? do {
        $_ = $.;
        tr/?-^/_-~/;
        s/\s.*/.ch/gmx;
        $_ = do {
            $0 =~ /j\w+/ ? $& . '@' : 'w' x 3 . '.'
        } . 'f-' . $_;
        $. . $_
    } : substr('lockpents ' . $., &a, 1);
}
sub p {
    print do {
        $#_ + 1 ? &a . "\n" : do {
            /\n/ ? $_ : $_ . ".\n"
        }
    };
}
sub x {
    exit;
}
sub t {
    select O(), &O, O(), &a;
}
x  if $v and {p($0 . " \251" . 2010 . ' ' . b())};
if ($j) {
    $_ = "\316x\271\cV\247\325I\325\220\2722\325";
    $_ = u(12, 1);
    s/.{4}/b ord u(O(), "$&", O());/egm;
    tr/@-[/`-{/;
    s[.][($. = $&) =~ tr/^-{/?-\\/;
    $.;]ex;
    p ;
    if ($c) {
        if ($c != 1) {
            $_ = $c . ' ';
            p ;
        }
        foreach $= (1 .. 2 * l()) {
            s/.//m;
            $_ .= $&;
            p "\e[A\r" . $_;
            t 0.1;
        }
    }
    x ;
}
$/ = O();
open $_, $0;
$_ = <$_>;
$p and do {
    p ;
    open $p, $p;
    p <$p>;
    x 
} unless $k and p  and x ;
if ($h) {
    $_ = 'Usage: ' . $0 . ' [ -v | -h | -j [-c[=string]] | -k | -p=file.pl ]';
    p ;
    x ;
}
'???';
- syntax OK

Well! We got something near readable, now. Do this alway give same result?

perl -MO=Deparse <(sed -e <japh.pl 's/pack("v",27000)/"xi"/') |
    sed -ne 's/$_ = \(qq(.*)\);/print \1/p' |
    perl |
    perl -MO=Deparse |
    perl -s /dev/stdin -j -c="That's all folks"
/dev/fd/63 syntax OK
- syntax OK
Just another perl hacker.
That's all folks .

(And the last line is animated:)

\$\endgroup\$
1
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use strict;*1=*CORE'die,*!=*=,@=='hacker',s??'&1(@!,$/)'?ee;s;;%ENV=~m
,..$,,$&+10;e,@!=(chr.'ust',~~reverse('rehtona'),'Perl',$@);&1("@{=}")

It works with strictures enabled. Although it does not work on all machines/perls, because of CORE'die and ~~%ENV.

$ perl
use strict;*1=*CORE'die,*!=*=,@=='hacker',s??'&1(@!,$/)'?ee;s;;%ENV=~m
,..$,,$&+10;e,@!=(chr.'ust',~~reverse('rehtona'),'Perl',$@);&1("@{=}")
^Z
Just another Perl hacker
\$\endgroup\$

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