gistfile1.rb

#!/usr/bin/ruby

# must place in dir containing the wukong code
$: << File.dirname(__FILE__)+'/wukong/lib'

require 'wukong'

module WordCount
  class Mapper < Wukong::Streamer::LineStreamer
    # Emit each word in the line.
    def process line
      words = line.strip.split(" ").reject(&:blank?)
      yield [words[4], 1]
    end
  end
  
  class Reducer < Wukong::Streamer::ListReducer
    def finalize
      total = 0
      counts = values.map(&:last).map(&:to_i)
      counts.each {|x| total += x}
      yield [ key, total ]
    end
  end
end
    
Wukong::Script.new(WordCount::Mapper, WordCount::Reducer).run