CLCS
Function

finish-output, force-output, clear-output

finish-output &optional output-stream ⇒ nil

force-output &optional output-stream ⇒ nil

clear-output &optional output-stream ⇒ nil

Arguments and Values

output-streaman output stream designator. The default is standard output.

Description

finish-output, force-output, and clear-output exercise control over the internal handling of buffered stream output.

finish-output attempts to ensure that any buffered output sent to output-stream has reached its destination, and then returns.

force-output initiates the emptying of any internal buffers but does not wait for completion or acknowledgment to return.

clear-output attempts to abort any outstanding output operation in progress in order to allow as little output as possible to continue to the destination.

If any of these operations does not make sense for output-stream, then it does nothing. The precise actions of these functions are implementation-dependent.

Examples

;; Implementation A
 (progn (princ "am i seen?") (clear-output))
⇒  NIL

;; Implementation B
 (progn (princ "am i seen?") (clear-output))
 |>  am i seen?
⇒  NIL

Affected By

*standard-output*

Exceptional Situations

Should signal an error of type type-error if output-stream is not a stream designator.

See Also

clear-input