initdia
(initdia [flag]))
The initdia function determines that certain commands which normally invoke a dialog box be performed at the command line when flag is set to 0.
In fact, you can initialize that in a Lisp routine the standard command (dialog box variant) is performed as its "Minus-Command" which is performed at the command line (for example initializes the call of initdia with flag set to 0 the use of the -Layer command instead of the Layer command.