Ruby/Tk script with GUI to print a folder using a system call to lp (CUPS). (Requires cups gem)

print_folder_tk.rb

#!/usr/bin/env ruby

require 'tk'
require 'tkextlib/tile'
require 'tkextlib/bwidget'
require 'cups'

$dirname = TkVariable.new

root = TkRoot.new {title "Print Folder"}
content = Tk::Tile::Frame.new(root) {padding "3 3 12 12"}.grid(:sticky => 'nsew')
TkGrid.columnconfigure root, 0, :weight => 1; TkGrid.rowconfigure root, 0, :weight => 1

Tk::Tile::Label.new(content) {text 'Folder to Print:'}.grid(:column => 1, :row => 2, :sticky => 'w')
Tk::Tile::Label.new(content) {textvariable $dirname }.grid(:column => 2, :row => 2, :sticky => 'we')
Tk::Tile::Label.new(content) {text 'Printer:'}.grid(:column => 1, :row => 1, :sticky => 'w')
Tk::Tile::Button.new(content) {text 'Print'; command { print_dirname }}.grid(:column => 1, :row => 3, :sticky => 'we')
Tk::Tile::Button.new(content) {text 'Select Folder'; command { get_dirname }}.grid(:column => 2, :row => 3, :sticky => 'we')
Tk::Tile::Button.new(content) {text 'Quit'; command 'exit'}.grid(:column => 3, :row => 3, :sticky => 'we')

$combobox = Tk::BWidget::ComboBox.new(content).grid(:column =>2, :row => 1, :sticky =>'w')
$combobox.values = Cups.show_destinations
$combobox.place('height' => 25,
		'width'  => 150,
		'x'      => 10,
		'y'      => 10)

TkWinfo.children(content).each {|w| TkGrid.configure w, :padx => 5, :pady => 5}
root.bind("Return") { get_dirname }

def get_dirname
  begin
    $dirname.value = Tk.chooseDirectory
  rescue
    $dirname.value = ""
  end
end

def print_dirname
  if $combobox.get.empty? || $dirname.value == "" then
    Tk.messageBox(
      'icon' => 'error', 'title' => 'ERROR',
      'message' => "Please make sure a printer and folder are selected.")
  else
    system "lp #{$dirname}/*.* -o fitplot -d #{$combobox.get}"
    Tk.messageBox('title' => 'Printing', 'message' => "Printing folder #{$dirname}")
  end
end

Tk.mainloop