trollop.rb

require 'trollop'

class Test
  attr_reader :a
  attr_reader :opts
  def initialize
    @a = 'qwer'
    @opts = Trollop::options do
      opt :monkey, "Use monkey mode"                     # a flag --monkey, defaulting to false
      opt :goat, "Use goat mode", :default => true       # a flag --goat, defaulting to true
      opt :num_limbs, "Number of limbs", :default => 4   # an integer --num-limbs <i>, defaulting to 4
      opt :qwer, 'Test', :default => "This is a - #{@a}"
      opt :num_thumbs, "Number of thumbs", :type => :int # an integer --num-thumbs <i>, defaulting to nil
    end

  end
end


a = Test.new()

puts("this is #{a.a} and it's good")


## if called with no arguments
p a.opts # => { :monkey => false, :goat => true, :num_limbs => 4, :num_thumbs => nil }

Не видит @A на 12-й строке