$url=~/(\d{4})\.htm/i;

##</code><code>##

$num = $1;

##</code><code>##

$url=~/(\d{4,})\.htm/i;

##</code><code>##

$url=~/(\d{4,5})\.htm/i;

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;
use v5.10;

my $url = 'something-12345.html'; 
$url =~ /(?<num>\d{4,5})\.htm/i;
my $num = $+{num};
print "$num\n";
exit;