after - Execute a command after a time delay

SYNOPSIS

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 command sleeps for ms milliseconds and then returns. While the command is sleeping the application does not respond to X events or any other events.

after ms ?arg arg arg ...?

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 concatenating all the arg 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 identifier that can be used to cancel the delayed command using after 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 command

This command also cancels the execution of a delayed command. The command argument specifies the text of the command to be cancelled. If there exists such a command among those whose execution is still pending, then it is cancelled and will never be executed; if no such command is currently pending then the after cancel command has no effect.

SEE ALSO

KEYWORDS