Flushing any pending output to the screenΒΆ

flush screen

Flush any pending output to the screen


SYNTAX

flush screen

Flushes any pending output to the screen.

The Sculptor windows system maintains two maps of the screen in memory, one representing the actual appearance of the screen, the other representing the way the screen should look if it were completely up to date. When a command sends output to the screen, only the second of these is initially updated. Unless the Sculptor system variable sys.AutoFlush is set to ON, the changes are flushed to the screen only when necessary - when an input command is executed, for example. Executing the flush screen command tells Sculptor to flush the screen now.

The existence of these two memory maps means that when Sculptor updates a screen it is able to send only those characters that have actually changed, thereby speeding up the screen display considerably.

The related Sculptor system variable sys.AutoFlush determines whether changes that update the screen are flushed after every output command.

If sys.AutoFlush is ON, changes that update the screen are flushed after every output command, automatically keeping the actual appearance of the screen completely up to date.

If sys.AutoFlush is OFF, then changes that update the screen are flushed only when necessary, such as when an input or flush screen command is given. It is useful to turn sys.AutoFlush OFF when executing several commands, all of which output to the screen, in circumstances where it is not necessary to update the screen until they are all completed.

The default for sys.AutoFlush is ON.


Note

Output may be flushed to the screen more often on a PC with the Memory Mapped option in the terminal parameter file set to Y. The flush screen command cannot be used as a means of keeping something hidden for a while, but only as a way of improving performance on a dumb terminal.