gistfile1.rb

require 'services/tinyurl'
require 'services/bitly'
require 'services/isgd'
require 'services/longurl'

services =
        {
         :tinyurl => TinyUrl.new,
         :bitly => BitLy.new,
         :isgd => IsGd.new,
         :expand => LongUrl.new
        }


default_service = :isgd
service = default_service
service = ARGV[1].to_sym unless ARGV[1].nil?
servicer = services[service]

puts servicer.shrink_url(ARGV[0])