examples/references/deep_copy.pl
#!/usr/bin/perl
use strict;
use warnings;

use Data::Dumper qw(Dumper);

my $ini = {
    'name' => {
            Foo => 123,
            Bar => 456,
    }
};

my $other_ini = { %{ $ini } };
print "$ini->{name}{Foo}\n";          # 123
print "$other_ini->{name}{Foo}\n";    # 123

$ini->{phone}{Baz} = 678;
print "$ini->{phone}{Baz}\n";         # 678
print "$other_ini->{phone}{Baz}\n";   # undef as expected
print Dumper $ini, $other_ini;

$ini->{name}{Foo} = 999;
print "$ini->{name}{Foo}\n";          # 999
print "$other_ini->{name}{Foo}\n";    # 999 !!!!
print Dumper $ini, $other_ini;

examples/references/deep_copy.out
123
123
678

$VAR1 = {
          'name' => {
                      'Bar' => 456,
                      'Foo' => 123
                    },
          'phone' => {
                       'Baz' => 678
                     }
        };
$VAR2 = {
          'name' => $VAR1->{'name'},
          'phone' => {}
        };
999
999
$VAR1 = {
          'name' => {
                      'Bar' => 456,
                      'Foo' => 999
                    },
          'phone' => {
                       'Baz' => 678
                     }
        };
$VAR2 = {
          'name' => $VAR1->{'name'},
          'phone' => {}
        };