Dumper and sorting of keys

When you use Dumper for debugging via comfortable logging data structures by reference, you can additionally apply sorting to the output. Say, you have a hash addressed by $hash_ref reference. If you need to output the hash contents, but have its keys sorted, you can do:

use strict;
use Data::Dumper;

$hash_ref = generate your hash here

$Data::Dumper::Sortkeys = \&my_filter;
print Dumper($hash_ref), "\n";

sub my_filter {
 my ($hash) = @_;
 # return an array ref containing the hash keys to dump
 # in the order that you want them to be dumped
        return [
            sort {$a <=> $b} keys %$hash
        ];
}