gistfile1.rb

# the hash
hash = Hash.new {|h,k| h[k] = 0}

# populate the hash
File.open('email').each do |line|
  line.split(/\s+/).each do |word| 
    hash[word] += 1
  end
end

# print, most occurrences first
hash.sort_by{|str,count| count}.reverse.each do |arr|
  str, count = *arr
  puts "#{str}: #{count}"
end