#!/usr/bin/perl

# http://perlmonks.org/?node_id=1207789

use strict;
use warnings;
use Data::Dumper;

my $big_string = 'special:1001:area_code:617|special:1001:zip_code:02205|special:1001:dow:0|special:1001:tod:14';

my %hash = map +(split /:/)[-2, -1], split /\|/, $big_string;

print Dumper \%hash;