count_token.rb

#!/usr/bin/env ruby1.9
# -*- coding: utf-8 -*-
require 'ripper'

result = Hash.new{ |h,k| h[k] = 0 }

ARGF.read.split(/\s/).each{ |file|
  Ripper.tokenize(open(file, "r:utf-8").read).each{ |token|
    result[token] += 1
  }
}

result.to_a.sort_by{ |pair| pair[1] }.reverse.each{ |pair|
  token, count = *pair
  puts "#{count} #{token.inspect}"
}