#!/usr/bin/perl
#################
#
# simple encoding using tr///
#
################
use strict;
use warnings;

my $plain = "Hi there boys and girls.  Are we having fun yet?";
(my $coded = $plain) =~ tr/a-zA-Z/d-za-cD-ZA-C/;
print "plain: '$plain'.\n";
print "coded: '$coded'.\n";
