YAML

Data::Dumper is not the only game on the island, though. Brian Ingerson came up with Yet Another Markup Language (YAML) to provide a more readable (and more compact) dump. It works in the same way as Data::Dumper. We'll see more about YAML when we talk about modules later, so we won't say much about it here.

use YAML;

my %total_bytes;

while (<>) {
        my ($source, $destination, $bytes) = split;
        $total_bytes{$source}{$destination} += $bytes;
        }

print Dump(\%total_bytes);

--- #YAML:1.0
ginger.girl.hut:
  maryann.girl.hut: 199
  professor.hut: 1218
professor.hut:
  gilligan.crew.hut: 1250
  lovey.howell.hut: 1360
thurston.howell.hut:
  lovey.howell.hut: 1250