use strict;
use warnings;

use CGI qw(a);
use URI::Find::Schemeless;

my $text   = do {local $/;<DATA>};
my $finder = URI::Find::Schemeless->new(
   sub { return a{href=>$_[0]->abs},$_[1] }
);

$finder->find(\$text);
print $text;

__DATA__
stuff stuff
http://foo.com/bar/qux.html stuff
stuff stuff
http://bar.com/baz.cgi?foo=bar stuff
stuff stuff
www.perlmonks.org/?node_id=255439