What was lacking a year ago was a clear direction for the user interface. Tk is an extension to Tcl that supports building graphical user interfaces under X-Windows. These are all similar. Let us consider the obey command. Args holds the optional arguments to the action.
Various options are available including -success command .
This specifies a Tcl command to be executed when and if the obey completes successfully. This specifies a Tcl command to be executed if the obey completes with an error. The Tk command button creates a button widget and pack makes it appear. The label of the button is specified with -text . A Tcl command to be executed when the button is pressed is specified with -command .