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### Re: PM Obfu

by husoft (Monk)
 on Oct 12, 2002 at 18:36 UTC ( #204798=note: print w/replies, xml ) Need Help??

Can you explain a few things I don't understand?

- First thing I don't understand is this way of making
subs (sub'i, sub'p, sub'f) what's the main difference
from the sub i{..}.

- Second, in this line : \;\$m.="\$/\$/\$/\$/\$/\$/1; I don't
really get what you are doing there.

- Third, \$/\$/\$/\$/\$/\$/\$/";; why ;;?

```#!/usr/bin/perl

\$m=q\\$g=59;
\$s=23;

@v=(\$",\$",'.',';','x','X','M');
\$t=[map{[(split('',\$_))[0..\$g]]}reverse+split(\$/,\$m)];

sub'i{
(\$b)=@_;
\$b->[0]=[(0)x(\$g+1)];

for(@{\$b->[0]}){
\$_=\$#v*(int(rand(7))<3);
}

for(1..(\$s)){
@{\$b}[\$_]=[(0)x(\$g+1)];
}
}
sub'p{
(\$b)=@_;
system(\$^O=~/MSWin32/ ? 'cls': 'clear');

\$str='';
for \$r(reverse(0..\$s)){
for \$c(0..\$g){
\$str.=(\$t->[\$r][\$c]eq\$"?\$":@v[int \$b->[\$r][\$c]]);
}\$str.=\$/;
}
print \$str;
}

sub'f{
(\$x)=@_;\$b=[];i(\$b);

for \$r(1..(\$s-1)){
for\$c(1..(\$g-1)){if(int(rand(2))){
\$v=0;for\$ri(-1..1){
for\$ci(-1..1){
\$v+=\$x->[\$r+\$ri][\$c+\$ci];
}
}

\$b->[\$r][\$c]=\$v/9;
}else{

\$b->[\$r][\$c]=\$x->[\$r-1][\$c];}}}
return \$b;

}

\$z=[];
i(\$z);
p(\$z);
while(1){
\$z=f(\$z);
p(\$z);
}

\;\$m.="\$/\$/\$/\$/\$/\$/1;
\$/\$/\$/\$/\$/\$/\$/";;
s//\$m/;
s/\$"//g;
s|\$/||g;
eval

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Re: Re: PM Obfu
by Felonious (Chaplain) on Oct 12, 2002 at 19:07 UTC
1) sub'i{} means the same as sub main::i {}, in this case it's used to get rid of the space (important because spaces are used as a mask).
2 and 3) these serve as filler to make the code rectangular and for tweaking the position of the mask over the output.

[TINPC@perlcabal.com shh]\$ su real

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