#amodule.rb
#!/usr/bin/ruby

module RubyModule
  def do_something
    #do nothing
  end
end


#main.rb
#!/usr/bin/ruby

require './amodule.rb'

RubyModule.do_something




#When I run "ruby main.rb", I get the following error:
#main.rb:5:in `<main>': undefined local variable or method `do_something' for main:Object (NameError)