ANSI Common Lisp 21 Streams 21.2 Dictionary of Streams
&optional input-stream eof-error-p eof-value recursive-p
- Arguments and Values:
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
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
- Affected By:
- Exceptional Situations:
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.
- See Also:
The corresponding output function is write-char.
- Allegro CL Implementation Details: