This gem can be used to drive a 3270 terminal emulator. You have to have a supported emulator installed on the machines on which you use the gem. Currently the supported emulators are EXTRA! X-treme by Attachmate, Quick3270 by DN-Computing, and X3270. The first two are commercial products and need to be purchased. X3270 is open source. Support for other emulators will be added as time permits.


You can view the RDocs for this project here.


Add this line to your application's Gemfile:

gem 'te3270'

And then execute:

$ bundle

Or install it yourself as:

$ gem install te3270


You can create classes that are similar to page-object classes. In these classes you can define the various fields that you wish to interact with on the screen.

class MainframeScreen
  include TE3270

  text_field(:userid, 10, 30, 20)
  text_field(:password, 12, 30, 20)

  def (username, password)
    self.userid = username
    self.password = password

emulator = TE3270.emulator_for :extra do |platform|
  platform.session_file = 'sessionfile.edp'
my_screen = MainframeScreen.new(emulator)
my_screen.userid = 'the_id'
my_screen.password = 'the_password'

If you are using this gem with cucumber then you can register the ScreenFactory module with the cucumber World like this:


You also need to setup some hooks to start and stop the emulator:

Before do
  @emulator = TE3270.emulator_for :extra do |platform|
    platform.session_file = 'sessionfile.edp'

After do

The X3270 emulator supports these hooks:

Before do
  @emulator = TE3270.emulator_for :x3270 do |platform|
    platform.executable_command = 'path to the x3270 executable'
    platform.host = 'name of host to connect to'
    platform.max_wait_time = 42  # defaults to 10
    platform.trace = true # turns on trace output from the emulator

This allows you to use the on method in your step definitions like this:

on(MainframeScreen).('the_user', 'the_password')

or you can use the version of on that takes a block like this:

on(MainframeScreen) do |screen|
  screen.userid = 'the_id'
  screen.password = 'the_password'

There is also a way to pass in a Hash and have it populate an entire screen. Just simply ensure the key for an entry in the Hash matches the name you gave a text field and it will find and set the value. This allows the gem to easily work with the DataMagic gem.

# given this Hash
my_data = { userid: 'the_id', password: 'the_password' }

# you can simply call this method
on(MainframeScreen).populate_screen_with my_data


  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request