gistfile1.txt

#!/usr/bin/env perl

use strict;
use warnings;

use Data::Dumper;

my $hash = {};

printf(Dumper($hash));

$hash->{some}->{key}->{here} = "check it out";

printf(Dumper($hash));

# $ ./autovivification.pl
# $VAR1 = {};
# $VAR1 = {
#           'some' => {
#                       'key' => {
#                                  'here' => 'check it out'
#                                }
#                     }
#         };