nop has asked for the wisdom of the Perl Monks concerning the following question:

This is a strange question, and asked for the purposed of an obfuscation exercise.
Is there a way for a running perl program to access its own source code (beyond using $0 to find its own name, opening its own .pl file, and slurping itself in)?

Replies are listed 'Best First'.
(jeffa) Re: Obfuscation: program seeing own source
by jeffa (Bishop) on Feb 08, 2001 at 03:07 UTC
    Mess around with this a bit: 
    seek(DATA,0,0);
print while(<DATA>);
__DATA__

    [download]
    Fun stuff ;)

    Jeff 

    L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
F--F--F--F--F--F--F--F--
(the triplet paradiddle)
[reply]
[d/l]
      Excellent!

      But why does seek(DATA,0,0); go to the start of the file, not the start of __DATA__ ?

      andy.

      update: so it's a handle for the script itself... on disk, presumably, rather than in memory? shame.

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

print "foo\n";

seek(DATA,0,0);

while (<DATA>) {
        s/foo/bar/ and ! /eval/ and eval ;
}

__DATA__

      [download]
      versus 
      #!/usr/bin/perl -w
use strict;

print "foo\n";

seek(DATA,0,0);

my @me = <DATA> ;

foreach (@me) {
        s/foo/bar/ and ! /eval/ and eval ;
}

foreach (@me) {
        s/bar/baz/ and ! /eval/ and eval ;
}

__DATA__

      [download]
[reply]
[d/l]
[select]
Quines
by MrNobo1024 (Hermit) on Feb 08, 2001 at 04:31 UTC
    I think what you're looking for is a quine (a program that displays its own source code without accessing it). Here's an example: 
    $q=q(print"\$q=q($q);$q";);print"\$q=q($q);$q";

    [download]
[reply]
[d/l]
Re: Obfuscation: program seeing own source
by Adam (Vicar) on Feb 08, 2001 at 03:17 UTC
[reply]
      I bought my camel shirt cool code too!
[reply]
Re: Obfuscation: program seeing own source
by MeowChow (Vicar) on Feb 08, 2001 at 04:35 UTC
    When a project calls for self-modifying or self-reading code {g}, I like to stick my code in $_ and eval it like so: 

    $_='
#obfuscated
#self-modifying code
#here
#and then
eval
#again if you want to get really messy
',eval;

    [download]
    Of course, there are other, more obfuscated ways to go about doing this too :-) 
       MeowChow                                               
                print $/='"',(`$^X\144oc $^X\146aq1`)[-2]
[reply]
[d/l]
Re: Obfuscation: program seeing own source
by arhuman (Vicar) on Feb 08, 2001 at 12:42 UTC

    See Morph on obfuscation section.
    For it's what I've done in this prog.

[reply]

Back to Seekers of Perl Wisdom