You probably meant

$title =~ s/%([0-9a-fA-F][0-9a-fA-F])/pack("c",hex($1))/ge;
[download]

But you'd almost certainly be better off with the uri_unescape function from URI::Escape.

--
<http://www.dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg