Pretty-printer for Ruby objects.

関数pは改行を入れてくれないので、オブジェクトが大きくなると出力が見にくくなります。そんなときはppを使うべし。適当に改行を入れてくれます。
以下サンプルスクリプト

require 'pp'

hash = {
  'key1' => 1,
  'key2' => 2,
  'key3' => 3,
  'key4' => 4,
  'key5' => 5,
  'key6' => 6,
  'key7' => 7,
  'key8' => 8,
}

p hash
# =>
# {"key1"=>1, "key2"=>2, "key3"=>3, "key4"=>4, "key5"=>5, "key6"=>6, "key7"=>7, "key8"=>8}
pp hash
# =>
# {"key1"=>1,
#  "key2"=>2,
#  "key3"=>3,
#  "key4"=>4,
#  "key5"=>5,
#  "key6"=>6,
#  "key7"=>7,
#  "key8"=>8}