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Index
two-way-stream Streams Dictionary interactive-stream-p
Function

input-stream-p, output-stream-p

input-stream-p stream ⇒ generalized-boolean

output-stream-p stream ⇒ generalized-boolean

Arguments and Values

streama stream.
generalized-booleana generalized boolean.

Description

input-stream-p returns true if stream is an input stream; otherwise, returns false.

output-stream-p returns true if stream is an output stream; otherwise, returns false.

Examples

 (input-stream-p *standard-input*) ⇒  true
 (input-stream-p *terminal-io*) ⇒  true
 (input-stream-p (make-string-output-stream)) ⇒  false

 (output-stream-p *standard-output*) ⇒  true
 (output-stream-p *terminal-io*) ⇒  true
 (output-stream-p (make-string-input-stream "jr")) ⇒  false

Exceptional Situations

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

Backlinks

broadcast-stream, Input, Output, and Bidirectional Streams, Introduction to Streams, Stream Arguments to Standardized Functions, Streams Dictionary, Symbols in the COMMON-LISP Package