The winfo command has just over 40 operations that return information about a widget or the display. The operations fall into the following categories:
Sending commands between applications.
Virtual root coordinates.
Atoms and IDs.
Colormaps and visuals.
Each Tk application has a name that is used when sending commands between applications using the send command, which is described in Chapter 40. The list of Tk applications is returned by the interps operation. The tk appname command is used to get the name of the application, and that command can also be used to set the application name. In Tk 3.6 and earlier, you had to use winfo name . to get the name of ...