How to (ab)use sort

sort is, like, the single most abusable function in all of Perl. Seriously, side effects in the sorting code!

use strict;
use warnings;()=
sort{index+0x47,&$a($b)}sub{print&{;pop}},
sort{sub J{$!++&1}[0]}sub{exec''},map{@$_}
sort{sub _{[(pop)x((1<<$!-->>47)|1)]}!{()=
sort{my$_=$a;$a=_(sub{$_})if!/0/}$a,$b,0}}
sort J('rke%ca hlrPe rhetoan tus;J')=~/./g
[download]

Obviously, this code depends on the internal, unspecified implementation of sort. I only tested it on Strawberry Perl 5.14.2 (64 bits); please let me know whether it works anywhere else. Edit: minor code improvements.

Comment on How to (ab)use sort Download Code

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Re: How to (ab)use sort by moritz (Cardinal) on Apr 17, 2012 at 09:04 UTC
`$ perl -v\|head -n2 This is perl 5, version 14, subversion 1 (v5.14.1) built for x86_64-li +nux $ perl obfu.pl Just another Perl hacker,Unknown warnings category 'CODE(0x1151998)' a +t obfu.pl line 6 BEGIN failed--compilation aborted at obfu.pl line 9.` [download] (with a pretty long pause after `Just another Perl hacker,`). Perl 6 - the future is here, just unevenly distributed	[reply] [d/l] [select]
Re^2: How to (ab)use sort by choroba (Cardinal) on Apr 17, 2012 at 09:21 UTC
Similar behaviour (plus a zero printed) in 5.10.1 for i486-linux-gnu-thread-multi.	[reply]
Re^3: How to (ab)use sort by Grimy (Pilgrim) on Apr 17, 2012 at 09:36 UTC
Thanks for the feedback :) Well, at least it prints what it's supposed to print before dying. s/use warnings/use warnings;@;=/ should fix this (both versions work with Strawberry, and the @;= version sounds less like an exploit).	[reply]
Re: How to (ab)use sort by biohisham (Priest) on Apr 22, 2012 at 16:33 UTC
`bioslayer@bioslayer:~/Desktop/Development/test$ perl - use strict; use warnings;()= sort{index+0x47,&$a($b)}sub{print&{;pop}}, sort{sub J{$!++&1}[0]}sub{exec''},map{@$_} sort{sub _{[(pop)x((1<<$!-->>47)\|1)]}!{()= sort{my$_=$a;$a=_(sub{$_})if!/0/}$a,$b,0}} sort J('rke%ca hlrPe rhetoan tus;J')=~/./g __END__ Just another Perl hacker0bioslayer@bioslayer:~/Desktop/Development/tes +t$` [download] Works as advertised, printing an extra 0 at the trail. `##Platform## Perl 5, version 12, subversion 4 (v5.12.4) built for i686-linux-gnu-th +read-multi-64int` [download] David R. Gergen said "We know that second terms have historically been marred by hubris and by scandal." and I am a two y.o. monk today :D, June,12th, 2011...	[reply] [d/l] [select]
Re: How to (ab)use sort by kcott (Archbishop) on Apr 23, 2012 at 00:15 UTC
G'day Grimy, I'm getting a different result under Mac OS X: ken@ganymede: ~/tmp $ cat pm_sort_abuse.pl use strict; use warnings;()= sort{index+0x47,&$a($b)}sub{print&{;pop}}, sort{sub J{$!++&1}[0]}sub{exec''},map{@$_} sort{sub _{[(pop)x((1<<$!-->>47)\|1)]}!{()= sort{my$_=$a;$a=_(sub{$_})if!/0/}$a,$b,0}} sort J('rke%ca hlrPe rhetoan tus;J')=~/./g ken@ganymede: ~/tmp $ perl pm_sort_abuse.pl Can't use string ("J") as an ARRAY ref while "strict refs" in use at p +m_sort_abuse.pl line 4. ken@ganymede: ~/tmp $ perl -v This is perl 5, version 14, subversion 2 (v5.14.2) built for darwin-th +read-multi-2level ... [download] -- Ken	[reply] [d/l]