If the idletasks keyword is specified as an argument to the command, then no new events or errors are processed; only when-idle idlers are invoked. This causes operations that are normally deferred, such as display updates and window layout calculations, to be performed immediately.
The update idletasks command is useful in scripts where changes have been made to the application's state and you want those changes to appear on the display immediately, rather than waiting for the script to complete. The update command with no options is useful in scripts where you are performing a long-running computation but you still want the application to respond to user interactions; if you occasionally call update then user input will be processed during the next call to update.
Copyright © 1990-1992 The Regents of the University of California. Copyright © 1994 Sun Microsystems, Inc. Copyright © 1995 Roger E. Critchlow Jr.