input-stream—an input stream designator. The default is standard input.
eof-error-p—a generalized boolean. The default is true.
eof-value—an object.
The default is nil
.
recursive-p—a generalized boolean. The default is false.
char—a character or the eof-value.
read-char
returns the next character from input-stream.
When input-stream is an echo stream,
the character is echoed on input-stream the first time the character is
seen.
Characters that are not echoed by read-char
are those that were
put there by unread-char
and hence are assumed to have been echoed
already by a previous call to read-char
.
If recursive-p is true, this call is expected to be
embedded in a higher-level call to read
or a similar
function used by the Lisp reader.
If an end of file2 occurs and eof-error-p is false, eof-value is returned.
(with-input-from-string (is "0123")
(do ((c (read-char is) (read-char is nil 'the-end)))
((not (characterp c)))
(format t "~S " c)))
▷ #\0 #\1 #\2 #\3
→ NIL
*standard-input*
,
*terminal-io*
.
If an end of file2 occurs before a character can be read, and
eof-error-p is true,
an error of type end-of-file
is signaled.
read-byte, read-sequence, write-char, read
The corresponding output function is write-char
.