require 'tk'

fbar = TkFrame.new.pack('fill'=>'x')
scr = TkScrollbar.new.pack('fill'=>'y', 'side'=>'right')
text = TkText.new.pack('side'=>'right')
text.yscrollbar( scr )
cut_buffer = ''

def open_file ( text )
  filename = Tk.getOpenFile
  file = open( filename )
    textdata = file.read
  file.close
  text.insert( 'end', textdata )
end

def save_file ( text )
  filename = Tk.getSaveFile
  textdata = text.get( '1.0','end' )
  file = open( filename, "w" )
    file.print( textdata )
  file.close
end

menu_spec = [
  [ ['File', 0],
    ['Open File', proc{open_file text}],
    ['Save File', proc{save_file text}],
    '---',
    ['Clear',  proc{ text.delete('1.0', 'end') }],
    '---',
    ['Quit',      proc{exit}]
  ],
  [ ['Edit', 0],
    ['Cut',       proc{ cut_buffer = text.get('sel.first', 'sel.last'); text.delete('sel.first', 'sel.last') }],
    ['Copy',      proc{ cut_buffer = text.get('sel.first', 'sel.last') }],
    ['Paste',     proc{ text.insert('insert',cut_buffer ) }]
  ]
]
TkMenubar.new(fbar, menu_spec, 'tearoff'=>false).pack('fill'=>'x', 'side'=>'top')

Tk.mainloop