Counting words in a web page and sorting them in order of frequency

wordcount.rb

require 'nokogiri'
require 'open-uri'

url = ARGV[0]

doc = Nokogiri::HTML(open(url))
all_words = doc.inner_text.split(/\s*[\W-[[:cntrl:]]]\s*/)
          .reject{|w| /^(\d*|\w)$/ =~ w}
          .map{|w| w.downcase}
          .sort
words = Hash.new(0)
all_words.each{|w| words[w] += 1}
words = words.sort{|a,b| b[1] <=> a[1]}
words.each do |w|
  puts "#{w[1]} #{w[0]}"
end