<code lang="Ruby">require 'getoptlong'
require 'tk'

class DummyFtpClient

  def initialize
    
    @host = nil
    @user = nil
    @password = nil
    
    opts = GetoptLong.new(
      [ "--host",     "-h",            GetoptLong::OPTIONAL_ARGUMENT ],
      [ "--user",     "-u",            GetoptLong::OPTIONAL_ARGUMENT ],
      [ "--password", "-p",            GetoptLong::OPTIONAL_ARGUMENT ]
    )
    opts.each { |opt,arg|
      case opt
        when '--host'
          @host = arg
        when '--user'
          @user = arg
        when '--password'
          @password = arg
      end
    }

    if @host.nil? || @user.nil? || @password.nil?
      get_missed_arguments
    end
  end

  def get_missed_arguments
    root = TkRoot.new('title' => 'Connection parameters')

    hostVar = add_entry(root, 'Host:', @host)
    userVar = add_entry(root, 'User:', @user)
    passwordVar = add_entry(root, 'Password:', @password)

    onConnect = proc {
      @host = hostVar.value unless hostVar.nil?
      @user = userVar.value unless userVar.nil?
      @password = passwordVar.value unless passwordVar.nil?
      Tk.exit
    }
    
    TkButton.new(root) {
      text 'Connect'
      command onConnect
    }.pack('padx' => 10, 'pady' => 10)
    Tk.mainloop
  end

  def add_entry(root, prompt, value)
    if value.nil?
      tkVar = TkVariable.new
      tkVar.value = value
      TkLabel.new(root) {
        text prompt
        pack { padx 5; pady 5 }
      }
      TkEntry.new(root, 'textvariable' => tkVar) {
        pack { padx 5; pady 5 }
      }
      return tkVar
    else
      return nil
    end
  end

  def connect
    puts "About to connect to #{@host} as #{@user}/#{@password}"
  end
  
end

client = DummyFtpClient.new
client.connect</code>