Perl: sort Data::Dumper

Default sort:

$Data::Dumper::Sortkeys  = 1;

Sort by keys:

$Data::Dumper::Sortkeys = sub { [sort {$a cmp $b} keys %{$_[0]}] };

Sort by values:

$Data::Dumper::Sortkeys = sub { [ sort { $_[0]->{$a} <=> $_[0]->{$b} } keys %{$_[0]} ] };