open-stream-p

open-stream-p stream → generalized-boolean

stream — a stream.

generalized-boolean — a generalized boolean.

Returns true if stream is an open stream; otherwise, returns false.

Streams are open until they have been explicitly closed with close, or until they are implicitly closed due to exit from a with-output-to-string, with-open-file, with-input-from-string, or with-open-stream form.

(open-stream-p *standard-input*) → true

close.

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