#!/usr/bin/env perl -l

use strict;
use warnings;

my @data = do { local $/ = ''; <DATA> };
my %urls = map { /^\[(\d+)/ => $_  } split /^/ => $data[-1];
print $data[$_], @urls{$data[$_] =~ /\[.*?\]\[(\d+)\]/g} for 0 .. $#data - 1;

__DATA__
This is a an example of [Markdown][1] footer links. I'm trying to use [Perl][2] to organize them more coherently.

But I'm getting too many newlines and I'm hoping the [PerlMonks][3] can help.

[1]: https://daringfireball.net/projects/markdown/
[2]: http://www.perl.org/
[3]: http://www.perlmonks.org/

##</code><code>##

This is a an example of [Markdown][1] footer links. I'm trying to use [Perl][2] to organize them more coherently.

[1]: https://daringfireball.net/projects/markdown/
[2]: http://www.perl.org/

But I'm getting too many newlines and I'm hoping the [PerlMonks][3] can help.

[3]: http://www.perlmonks.org/