clear-input &optional input-stream => nil
Arguments and Values:
input-stream---an input stream designator. The default is standard input.
Clears any available input from input-stream.
If clear-input does not make sense for input-stream, then clear-input does nothing.
;; The exact I/O behavior of this example might vary from implementation ;; to implementation depending on the kind of interactive buffering that ;; occurs. (The call to SLEEP here is intended to help even out the ;; differences in implementations which do not do line-at-a-time buffering.) (defun read-sleepily (&optional (clear-p nil) (zzz 0)) (list (progn (print '>) (read)) ;; Note that input typed within the first ZZZ seconds ;; will be discarded. (progn (print '>) (if zzz (sleep zzz)) (print '>>) (if clear-p (clear-input)) (read)))) (read-sleepily) >> > 10 >> > >> >> 20 => (10 20) (read-sleepily t) >> > 10 >> > >> >> 20 => (10 20) (read-sleepily t 10) >> > 10 >> > 20 ; Some implementations won't echo typeahead here. >> >> 30 => (10 30)
The input-stream is modified.
Should signal an error of type type-error if input-stream is not a stream designator.