Here we will described the functions that don’t fit into any of the above categories and are essentially housekeeping functions.
There is a predicate that returns a reference to the main window of a Tcl/Tk interpreter:
which given a reference to a Tcl interpreter Tclnterpreter, returns a reference to its main window in TkWindow.
The window reference can then be used in
which destroys the window or widget referenced by TkWindow and all of its sub-widgets.
tk_make_window_exist/1 also takes a window
which causes the window referenced by TkWindow in the Tcl interpreter TclInterpreter to be immediately mapped to the display. This is useful because normally Tk delays displaying new information for a long as possible (waiting until the machine is idle, for example), but using this call causes Tk to display the window immediately.
There is a predicate for determining how many main windows, and hence Tcl/Tk interpreters (excluding simple Tcl interpreters), are currently in use:
which returns an integer in the variable NumberOfWindows.