|input-stream||an input stream, default is standard input|
|eof-error-p||a boolean, true (default) is EOF should be signaled|
|eof-value||an object that is returned as EOF value|
|recursive-p||flag to note recursive processing|
READ-CHAR function reads a character from input stream.
(let ((s (make-string-input-stream (format nil "line 1~%line 2~%line 3)")))) (read-char s)) => #\l