Obfuscation, Golfing and Secret Operators in Perl

OGSOPObfuscation, Golfing and Secret Operators in Perl

難読化・Perl Golf・ひみつの演算子

1

Obfuscation難読化

2

How do I impress my friends who don’t know much Perl

with obfuscation?

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With simple things

4

#!/usr/bin/perl $:?do{exit&&exit}:print"Just another Perl hacker,"

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#!/usr/bin/perl $:?do{exit||exit}:print"Just another Perl hacker,"

6

Spaces? What spaces?

$:?do{exit&&exit}:print"Just another Perl hacker,"

スペース？　どれよ？

7

#!/usr/bin/perl$:? do {exit &&exit } : print“Just another”.“ Perl hacker,”

Use newlines...

8

#!/usr/bin/perl$:?do{exit&&exit }:print“Jus”.“t a”.“not”.“her”.“ Pe”.“rl “.“hac”.“ker,”

As many as you can...

9

if($var) {$var = 0 }else {$var = 1 }

Forget about indentation

10

if($var) {$var = 0 } else {$var = 1 }

Or at least use it wrongly

11

print "Hello " ;print "World"

Semicolons: use wrongly

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;;;;;;;;;;;;;;;;;;;;;;;;;print "Hello World";;;;;;;;;;;;;;;;;;;;;;;;;

;;s;;print "Hello World";e;;

Semicolons: use plenty

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$a++ ; $b--$a++ , $b--$a++ . $b--$a++ .. $b--

Semicolons: use alternatives

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s//Just another Perl hacker,/ ; print

Use things indirectly

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Bend the rules

s/ / /;y/ / /;

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Bend the rules

s; ; ; ;s { }[ ]s s s sy ; ; ;;y y y y

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And use unneeded things

; s ; ; ; ;{ };s{ }[ ]s s s s s; y ; ; ; ;

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Mix them together

y s y s y ss y s y s y

19

Mix things up

1?s::::0

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Mix things up

1 ? s::: : 0

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Is it code?

y//No, it is not/;

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Is it a comment?

s##No, it is not#;

23

Is it a comment?

s##we want to print "Just another Perl hacker,"##

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Is it a comment?

s;;;;s ##we want to print "Just another Perl hacker,"##

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Is it a comment?

s;;;;s##we want to print "Just another Perl hacker,"##

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Is it a comment?

s;old;new;g;s##we want to print "Just another Perl hacker,"##

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Is it a comment?

s;old;new;g;s##we want to print "Just another Perl hacker,"##;s^.{11}^^&&eval;

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Are those brackets closed?

{y/}/{/}

29

WYSINWYG

$ perl -le ‘print “All digits!” if 0x20 =~ /^\d+\z/’All digits!

$ perl -le ‘print 0x2032

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WYSINWYG

print "No underscores!" if 1_234_567_890 !~ /_/; print "No e!" if 1e6 !~ /e/; print "There is an e!" if 6666666666666666 =~ /e/; print "There is a plus!" if 1e15 =~ /\+/; print "No dot!" if 0.00 !~ /\./;

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Hexadecimal or... whatever

eval "\x70\x72\x69\x6e\x74";

eval "\160\x72\151\x6e\164";

$_="0741171151160320971101111161041011140320801011". "14108032104097099107101114046";s;...;print chr$&;eg

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$;$:$_$^@^

Variable names

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$ ;$ :$ _$ ^@ ^

Variable names: and behold

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1 ? s : $ s : : : 0

Variable names: mix them

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1 ? s : s $ s : s $ s : : 0

Variable names: cleverly

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print ${1+1}

Variable names: calculate

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print ${$_}

Variable names: store them

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@_=(Just,another,Perl,hacker);$,=$”;print@_

$,=” another Perl “;print(“Just”,”hacker”);

Special variables

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y/a-z/:-z/

Behind human capabilities

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|&^~

Use uncommon things

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print “a” | “c”;print ~0 & 2 ;print 1 ^ 2 ;print ~0;

Use uncommon things

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sub _ { “something tricky” }_$_

so you can do clever things

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$_ = sub _ { “something tricky” }&{$_}

or don’t name it at all

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s;;;

And be inventive

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;;;;s;;;;

And be *very* inventive

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g;;;s;;;g

And be *VERY* inventive

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Example例

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print "Just another Perl hacker,"

JAPH

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print "Just ", "another ", "Perl ", "hacker,"

JAPH

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$, = " ";print "Just", "another", "Perl", "hacker,"

JAPH

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$, = " "; print reverse "hacker,", "Perl", "another", "Just"

JAPH

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$, = " "; print reverse"hacker,","Perl","another","Just"

JAPH

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$, = " "; push@,,$_ for reverse"hacker,","Perl","another",”Just”;

print @_

JAPH

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$, = $" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;

print @_

JAPH

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$, =+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;

print @_

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;

print @_

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”; join$,,@_ ;print $_

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s //join$,,@_/e;print $_

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s //”join”.’$,,@_’/ee;print $_

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s //"\x6a\x6f\x69\x6e".’$,,@_’/ee;print $_

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s //"\x6a\x6f\x69\x6e".’$,,@,’/ee;print $_

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s //"\x6a\x6f\x69\x6e".’$,,@,’/ee;print

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s{}/"\x6a\x6f\x69\x6e".’$,,@,’/ee;print

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s{};"\x6a\x6f\x69\x6e".’$,,@,’;ee;print

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s{};"print \x6a\x6f\x69\x6e".’$,,@,’;ee;eval

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s{};"print \x6a\x6f\x69\x6e".’$,,@,’;eee

JAPH

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+$,=+$" ; push@,,$_ for reverse"hacker,","Perl","another",”Just”;s{};"\160\162\151\156\164 \x6a\x6f\x69\x6e".’$,,@,’;eee

JAPH

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(+$,=+$"). push@,,$_ for reverse"hacker,","Perl","another",”Just”;s{};"\160\162\151\156\164 \x6a\x6f\x69\x6e".’$,,@,’;eee

JAPH

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(+$,=+$").#s# most people # think # this is a comment #push@,,$_ for reverse"hacker,","Perl","another",”Just”;s{};"\160\162\151\156\164 \x6a\x6f\x69\x6e".’$,,@,’;eee

JAPH

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Warning警告

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Don’t you ever, ever, ever, run obfuscated code you don’t

understand and cannot trust

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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see

Random code on the web

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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|‘{; ; y; -/:-@[-‘{-};‘-{/" -;;s;;$_;see


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So what’s on $_ afterall?


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So what’s on $_ afterall?

system”rm -rf /”


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Golfingゴルフ

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One character variables

$c $d $e $f $g

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If you don’t need it...

print “something”;

print”something”

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Forget about \n

s/\n//;

s///;

$_=”something\n”

$_=”something“

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END in the beginning

something;END{something_else}

END{something_else}something

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Learn the alternatives

map{[$_]}@array

map[$_],@array

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for the other way around

for(@a){something}

something for@a

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Learn the switches

#!/usr/bin/perlprint”this\n”;print”that\n”;print”the other\n”;

#!/usr/bin/perl -lprint”this”;print”that”;print”the other”;

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Learn the special variables

#!/usr/bin/perl@_=qw/Just another Perl hacker,/;print join” “,@_

#!/usr/bin/perl@_=qw/Just another Perl hacker,”;print”@_”

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Golfing techniques

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Golfing techniques

$_ x=

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Golfing techniques

What does this do?

$_ x= / /;

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Golfing techniques

y///c

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Secret Operatorsひみつの演算子

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Secret Eskimo Greeting

}{

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#!/usr/bin/perl -n# What does this do?}{print$.

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$ perldoc -perlrun

[...]

#!/usr/bin/perlLINE: while (<>) { ... # your program goes here }

[...]

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#!/usr/bin/perlLINE: while (<>) {}{print$. }

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Supermarket Trolley

@{[]}

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Supermarket Trolley

my @stuff = qw/pocket_watch 3ninja_tshirts/;

print "Our list includes: @{[map {ucfirst} @things_for_my_other_talks]}."

print "Our list includes: ", map {ucfirst} @things_for_my_other_talks], "."

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Supermarket Trolley




my @new_list = map {ucfirst} @things_for_my_other_talks;

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Supermarket Trolley




my @new_list = map {ucfirst} @things_for_my_other_talks;

print "Our list includes: @new_list."

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Goatse

=()=

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Goatse

my $_ = "Just another Perl hacker,";my $spaces =()= / /g

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Inchworm on a stick

~-

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Inchworm on a stick

What does this do?

$y = ~-$x*4;

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Inchworm on a stick

What does this do?

$y = ~-$x*4;$y = ($x-1)*4;

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Inchworm on a stick

What does this do?

$y = ~-$x*4;$y = ($x-1)*4;

High precedence decrement

(or a high precedence increment, if $x<0)

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///

///

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///

What does this do?

print ///4;

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///

What does this do?

print ///4;print //; # prints 1

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///

What does this do?

print ///4;print //; # prints 1print 1/4; # prints 0.25

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///

What does this do?

print ///4;print //; # prints 1print 1/4; # prints 0.25print ///4; # prints 0.25

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Inchworm

~~

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Inchworm

What does this do?

print ~~ gmtime

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Inchworm

$ perl -e 'print gmtime'31441214410831340

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Inchworm

$ perl -e 'print gmtime'31441214410831340

$ perl -e 'print ~~ gmtime'Wed May 14 12:44:35 2008

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Min Max

[ ]->[ ]

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Min Max

What does this do?

[ $x => $y ]->[ $y <= $x ]

128

Min Max

What does this do?

[ $x => $y ]->[ $y <= $x ]

...that’s the lesser of $x and $y

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Min Max

What does this do?

[ $x => $y ]->[ $y <= $x ]

...that’s the lesser of $x and $y

[ $x => $y ]->[ $x <= $y ]

...and that’s the greater of $x and $y

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Examples例

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Erudil’s Camel Code #!/usr/bin/perl -w # camel codeuse strict;

$_='ev al("seek\040D ATA,0, 0;");foreach(1..3) {<DATA>;}my @camel1hump;my$camel; my$Camel ;while( <DATA>){$_=sprintf("%-69s",$_);my@dromedary 1=split(//);if(defined($_=<DATA>)){@camel1hum p=split(//);}while(@dromeda ry1){my$camel1hump=0 ;my$CAMEL=3;if(defined($_=shif t(@dromedary1 ))&&/\S/){$camel1hump+=1<<$CAMEL;} $CAMEL--;if(d efined($_=shift(@dromedary1))&&/\S/){ $camel1hump+=1 <<$CAMEL;}$CAMEL--;if(defined($_=shift( @camel1hump))&&/\S/){$camel1hump+=1<<$CAMEL;}$CAMEL--;if( defined($_=shift(@camel1hump))&&/\S/){$camel1hump+=1<<$CAME L;;}$camel.=(split(//,"\040..m`{/J\047\134}L^7FX"))[$camel1h ump];}$camel.="\n";}@camel1hump=split(/\n/,$camel);foreach(@ camel1hump){chomp;$Camel=$_;y/LJF7\173\175`\047/\061\062\063\ 064\065\066\067\070/;y/12345678/JL7F\175\173\047`/;$_=reverse; print"$_\040$Camel\n";}foreach(@camel1hump){chomp;$Camel=$_;y /LJF7\173\175`\047/12345678/;y/12345678/JL7F\175\173\0 47`/; $_=reverse;print"\040$_$Camel\n";}';;s/\s*//g;;eval; eval ("seek\040DATA,0,0;");undef$/;$_=<DATA>;s/\s*//g;( );;s ;^.*_;;;map{eval"print\"$_\"";}/.{4}/g; __DATA__ \124 \1 50\145\040\165\163\145\040\157\1 46\040\1 41\0 40\143\141 \155\145\1 54\040\1 51\155\ 141 \147\145\0 40\151\156 \040\141 \163\16 3\ 157\143\ 151\141\16 4\151\1 57\156 \040\167 \151\164\1 50\040\ 120\1 45\162\ 154\040\15 1\163\ 040\14 1\040\1 64\162\1 41\144 \145\ 155\14 1\162\ 153\04 0\157 \146\ 040\11 7\047\ 122\1 45\15 1\154\1 54\171 \040 \046\ 012\101\16 3\16 3\15 7\143\15 1\14 1\16 4\145\163 \054 \040 \111\156\14 3\056 \040\ 125\163\145\14 4\040\ 167\1 51\164\1 50\0 40\160\ 145\162 \155\151 \163\163 \151\1 57\156\056

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Saturn

#!/usr/bin/perl ;;;;;; ;;;;;;;;;;; ;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;; +$I=sub{+s+^+ ;;;;;;; ;;;;;;;;; $"x$_[1]+gem;$/x$_# ;;;; ;;;;;;;; [0].$_.$/};$W=sub{$~=!q~ ;;;;;;; ~.pop();system($^O=~Win?ClS:# ;;;;;;; 'clear'),print,select$Z,$Z,$Z,!" ;;;;;; "||$~for@_};$H=sub{+join$/,map($_# ;;;;;; x$_[0],pop=~m-.+-g),!_};$_=!Mima,s-- ;;;;; "@{['=9+)w'^RINGS]}\%;local@{[Saturn^# ;;;;; wNXIBP]}"-see;s-^#!..+?$/(?=$"+;)--is ;;;; y-;-'-;s-\w-~-gi;$S=$_;#--Beautiful] ;;;; @S=m-.+-g;$N=1+.6-!th_,$--=-82-$--- ;;; $_.=$"x-(y---c-$-)for@S;$R=sub{$i# ;;; -d =0;join$/,map{$j=$%;join!_,grep# ;;; Rhea !($j++%$_[$%]),m-.-g}grep!($i# ;;; -Titan ++%$_[0]),@S};$L=join!_,map# ;;; -Huygens ~~reverse.$/,@S;@R=(&$I(q- ;;; -&&20,051, $_=_^q-q-),&$I(20,41-!q- ;;; -,$_=F|K),$ I->(15,31,$_=&$R(4-!q- ;;; -)),&$I(13-!" ;;",28,$_=&$R(3)),&${ ;;; _^_^I}(10,20-!" ;;;;;",$_=$R->(2)),q- ;;; -&&$S);@O=map&{" ;;;;;; "&&$H}($_,&${ ;;; R.!-_}($_))x$_,!" ;;;;; "+2..2*~~2 ;;; @Y=reverse@R#Dione ;;;;;; &${m-- ;;; S|A|T|U}(@R,$N)||!q- ;;;;;;; b- ;;; &$W(@O[0,1,2,1,0!=!q- ;;;;;;; ;;;; -],!1!~~1);&$W($S.!q- ;;;;;;;;; ;;;;; -,$L,0.16)for$%..5+!q- ;;;;;;;;;; ;;;;;;;;; Cassini-;&{$W||q- ;;;;;;;;;;;;;;;;;;;;;; -}(@Y,1.6) ;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;

133

Space Invaders

#!/usr/bin/perl

use strict; use Term'ReadKey;ReadMode 'cbreak';$,=$/;$/=++$b+$b;$=='8';$b=$= x28;$*=$=x2;@!=(qw(4 _ " a 1 1 0 0 ));$![7]=`clear`;push(@!,split shift(@!),q 7$=W8W$=8$b eq "j"8W$=8$=W8 $b eq"l"8W$=8W!8($b eq"k"&&$_!~/!/)a#W$=8#$=W8$=W#8W$=#8#!8##a\*8$=8p$=8$=p 8$=q8q$=8p(#.{59})$=8$=$ 1q8#q(.{60})$=8#$=$1 pap(.{60})!8$![0]++;"\*$ 1$="8q(.{60})!8$![0] ++;"\*$1$="8(t.*)!8$b=(l ength$1)-61;substr($ 1,0,$b )."!". substr($1, $b+1).$=4x"gs'"x"c"es'"c"z"gs if'.shift"z"l"just another perl hacker"l4'SpaceInvaders'.($=x12).'[email protected] j=left k=fire l=right'_'#'x58_("$*p$*"x11).$=x3_$*.("$*$*q"x11).$=_("p$*$*"x11).$=x3_($=x3).("$*$*q"x11)_1_$b.$=."W$b"_'#'x 587);j(split shift@!,pop@!);a(split shift@!,pop@!);push(@!,split shift@!,pop@!);$_=$a;map{s/\n//g}@!;map{s/v//g}@!;map{s/ //g}@!;&p;sub'j{$_=shift;$a.=m/^1/?("#$b$=$=$b#$,"x12):"#".eval( )."#$,";@_&&j(@_)}sub'END{ReadMode 'normal' }sub'a{eval"sub'".pop().'{eval\'s/\'.(shift).\'/\'.(shift).\'/'.pop().';@_&&'.pop().'(@_)}';@_&&a(@_)}sub'p{$b=ReadKey -1;$![1]%3==0&&x(split$=,$![6]);z(split$=,$![4]);x(split$=,$![5]);c(split$=,$![7]);$![1]++;select+(@-,@-,@-,0.05);($![2]=$_)=~s/$=/ /g;/pW|Wq/&&h('Game over');$_!~/p|q/&&h('You saved our planet. Yeah');print$![3],$![2 ];&p}sub h{print $![ 3],shift,"You killed $![0] space invaders ",$,;exit}

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mailto:[email protected]

mailto:[email protected]

Obfuscation, Golfing and Secret Operators in Perl

Technology

Transcript of Obfuscation, Golfing and Secret Operators in Perl