Guess the encoding of a line-based resource on the web and print it to STDERR, followed by the contents

guess.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'open-uri'
require 'csv'
require 'charlock_holmes'

def read(url)
  contents = File.read(open(url))

  detection = CharlockHolmes::EncodingDetector.detect(contents)
  STDERR.puts detection[:encoding]

  utf8_encoded_content = CharlockHolmes::Converter.convert contents, detection[:encoding], 'UTF-8'

  CSV.new(utf8_encoded_content, headers: :first_row).each do |line|
    puts line
  end
end

ARGV.length == 1 or abort 'No file argument given'

read(ARGV[0])