after(n)		     Ck Built-In Commands		      after(n)



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NAME
       after - Execute a command after a time delay

SYNOPSIS
       after ms
       after ms ?script script script ...?
       after cancel id
       after cancel script script script ...
       after idle ?script script script ...?
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DESCRIPTION
       This  command is used to delay execution of the program or to execute a
       command in background after a delay.  It has several  forms,  depending
       on the first argument to the command:

       after ms
	      Ms  must	be an integer giving a time in milliseconds.  The com-
	      mand sleeps for ms milliseconds and  then	 returns.   While  the
	      command  is  sleeping  the  application does not respond to key-
	      presses or any other events.

       after ms ?script script script ...?
	      In this form the command returns immediately,  but  it  arranges
	      for  a  Tcl  command  to	be executed ms milliseconds later as a
	      background event handler.	 The delayed command is formed by con-
	      catenating  all  the script arguments in the same fashion as the
	      concat command.  The command will be executed  at	 global	 level
	      (outside	the context of any Tcl procedure).  If an error occurs
	      while executing the delayed command then the  tkerror  mechanism
	      is used to report the error.  The after command returns an iden-
	      tifier that can be used to cancel the delayed command using  af-
	      ter cancel.

       after cancel id
	      Cancels  the  execution of a delayed command that was previously
	      scheduled.  Id indicates which command should be	canceled;   it
	      must  have  been the return value from a previous after command.
	      If the command given by id has already been  executed  then  the
	      after cancel command has no effect.

       after cancel script script ...
	      This  command  also  cancels the execution of a delayed command.
	      The script arguments are concatenated together with space	 sepa-
	      rators  (just  as in the concat command).	 If there is a pending
	      command that matches the string, it is cancelled and will	 never
	      be  executed;   if no such command is currently pending then the
	      after cancel command has no effect.

       after idle script ?script script ...?
	      Concatenates the script arguments together with space separators
	      (just  as in the concat command), and arranges for the resulting
	      script to be evaluated later as an idle handler (the script runs
	      the  next	 time  the  Tk	event loop is entered and there are no
	      events to process).  The command returns an identifier that  can
	      be used to cancel the delayed command using after cancel.	 If an
	      error occurs while executing the script then the tkerror	mecha-
	      nism is used to report the error.


SEE ALSO
       tkerror


KEYWORDS
       cancel, delay, sleep, time



Ck				      8.0			      after(n)
