use warnings;
use strict;

use Data::Dumper;
use JSON;

my %data;

for (0..10){
    $data{$_} = $_ * 5;
}

my $json = encode_json \%data;

open my $wfh, '>', 'saved.json'
  or die "can't open the damned file for writing!: $!";

print $wfh $json;
close $wfh;

open my $fh, '<', 'saved.json'
  or die "can't open the damned file for reading!: $!";

my $perl_href;

{
    local $/;
    $perl_href = decode_json $json
}

print Dumper $perl_href;