Perl hash-based config

file.cfg

{
  author  => 'sergio',
  handle  => 'smpb',
  country => 'portugal',

  complexity => {
    number  => 4,
    depth   => [ 'a', 'b', 'c' ]
  }
}

load_config.pl

#!perl

use 5.014;
use warnings;

use Data::Dumper;

open my $fh, '<', $ARGV[0]; 
my $contents = do { local $/; <$fh> };
close $fh;

my $config = eval $contents;
die "Config file did not return a hashref.\n"
  unless ref $config && ref $config eq 'HASH';

foreach my $key (keys %{$config})
{
  say "$key => $config->{$key}";
}

say Dumper $config;