Calculates the difference between the editor contents and the disk file for the selected document, and shows the difference with the default application. Requires diff(1).
Berekent it ferskil tusken de ynhâld fan de bewurker en de triem op skiif foar it selektearre dokumint, en lit it ferskil sjen mei de standert applikaasje. Fereasket diff( 1).