update(5)

                                 update(1tcl)
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   update -- process pending events and idle callbacks 

Synopsis

   update [idletasks]

Description

   This command is used to bring the application ``up to date'' by
   entering the event loop repeated until all pending events (including
   idle callbacks) have been processed.

   If the idletasks keyword is specified as an argument to the command,
   then no new events or errors are processed; only idle callbacks 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. Most display updates are performed as idle callbacks, so
   update idletasks will cause them to run. However, there are some kinds
   of updates that only happen in response to events, such as those
   triggered by window size changes; these updates will not occur in
   update idletasks.

   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 events such as user interactions; if you
   occasionally call update then user input will be processed during the
   next call to update.
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   25 April 2004
   © 2004 The SCO Group, Inc. All rights reserved.
   UnixWare 7 Release 7.1.4 - 25 April 2004