gistfile1.rb

#!/usr/bin/env ruby
require 'optparse'

radix = 36

OptionParser.new do |opt|
  opt.on('-d') { radix = 10 }
  opt.on('-z') { radix = 36 }
  opt.on('-r VAL') {|v| radix = Integer v }
  opt.parse! ARGV
end

def bad_url; abort "Please specify the URL to Twitter's status"; end

url = ARGV.shift
bad_url unless url

STATUS_URL_REGEXP = /^https?:\/\/twitter\.com\/\w+\/status(?:es)?\/(\d+)\/?$/
status_id = STATUS_URL_REGEXP.match(url).to_a[1]
bad_url unless status_id

case radix
when 10
  puts "http://ex.itter.ch/#{status_id}"
when 36
  puts "http://#{status_id.to_i.to_s radix}.itter.ch/"
else
  abort 'The radix should be 10 or 36'
end