Mark Dominus@mjd@mathstodon.xyz

Philippe Bruhat brought to my attention that someone is selling shirts on Redbubble with my prizewinning obfuscated Perl program. (This is not a complaint.) Unfortunately the code is illegible in the catalog pictures.

Here it is though:

@p=split//,".URRUU\c8R";@d=split//,"\nrekcah xinU / lreP rehtona tsuJ";sub p{
@p{"r$p","u$p"}=(P,P);pipe"r$p","u$p";++$p;($q*=2)+=$f=!fork;map{$P=$P[$f^ord
($p{$_})&6];$p{$_}=/ ^$P/ix?$P:close$_}keys%p}p;p;p;p;p;map{$p{$_}=~/^[P.]/&&
close$_}%p;wait until$?;map{/^r/&&<$_>}%p;$_=$d[$q];sleep rand(2)if/\S/;print

(It fits exactly into four lines of 77 characters each, perfect for a Usenet signature…)

redbubble.com/i/t-shirt/Just-P

RedbubbleRedbubble"Just Perl things..." Classic T-Shirt by sa1xPerl Scripts are awesome... look at my awesome and clean script! • Millions of unique designs by independent artists. Find your thing.
Mark Dominus@mjd@mathstodon.xyz

Replying to @mjd@mathstodon.xyz

I thought this probably wouldn't work with recent Perls, but i tried it with 5.38.2 just now and was delighted to find out that it does run correctly!

I was sure that Perl had deprecated the `"\c8"` escape long ago. This asks Perl to construct a string containing the character control-8.

(There is no such character as control-8.)

But it did do _something_, and my program depends on it doing that thing. Which it still does! Thanks p5p for retaining this crucial backward-compatibility feature.

Jul 5, 2026, 13:59 UTCen