lispdoc - results for peek-byte

(flexi-streams:peek-byte flexi-input-stream &optional peek-type (eof-error-p)
 eof-value)
Undocumented
  
(peek-char &optional (peek-type nil) (stream *standard-input*) (eof-error-p t)
 eof-value recursive-p)
Undocumented
Example:
(defun skip-whitespace (stream)
  "Skip over XML whitespace in stream, return first non-whitespace
  character which was peeked but not read, return nil on eof"
  (loop
   (let ((char (peek-char nil stream nil nil)))
     (if (and char (whitespace-char-p char))
         (read-char stream)
         (return char)))))
Mentioned in:
CLtL2 - 21.2. Creating New Streams
CLtL2 - 22.2.1. Input from Character Streams
HyperSpec - Function PEEK-CHAR
PCL - extracting information from an id3 tag
Successful Lisp - chapter19