I see you're dealing with a Tk::TextUndo. Taking a quick peek at the docs, I see it says "see also" Tk::Text (if you look inside TextUndo you'll see use base qw(Tk::Text);). A Tk::Text widget has many methods available to it, and they're mostly documented (if they're not, look at the source or try perltk.org). Also, the Tk widget demo contains lots of examples.