But this goes only one level deep. For "deeper" hash structures (like $object->{level1}{level2}=$value) this fails. See example:

use strict;
use Data::Dumper;

my $x = { a => 1, b => 2, aa => { aaa => 11 } };
print Dumper($x);

my $y = { c => 3, d => 4, aa => { bbb => 11 } };
print Dumper($y);

$x = { %$x, %$y };
print Dumper($x);
[download]

Gives (see below) with "aaa" key in 'aa'=>'aaa'=>22 lost

$VAR1 = { 'c' => 3,
          'a' => 1,
          'b' => 2,
          'd' => 4,
          'aa' => {
                    'bbb' => 11
                  }
        };
[download]

UPDATE: check this thread how to do it using Hash-Merge http://www.perlmonks.org/?node_id=1015801 In a nut shell, add as appropriate:

use Hash-Dumper qw/merge/;
[download]

and modify

$x = { %$x, %$y };
[download]

to

$x = merge( $x, $y );
[download]

and resulting hash will look much better

$VAR1 = {
          'c' => 3,
          'a' => 1,
          'b' => 2,
          'd' => 4,
          'aa' => {
                    'bbb' => 11,
                    'aaa' => 11
                  }
        };
[download]