lispdoc - results for peek-char

(peek-char &optional (peek-type nil) (stream *standard-input*) (eof-error-p t)
 eof-value recursive-p)
(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"
   (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
(chunga:peek-char* stream &optional eof-error-p eof-value)
Function: We're simulating PEEK-CHAR by reading a character and putting it into *CHAR-BUFFER*.
(trivial-gray-streams:stream-peek-char stream)
Function: This is used to implement PEEK-CHAR; this corresponds to PEEK-TYPE of NIL. It returns either a character or :EOF. The default method calls STREAM-READ-CHAR and STREAM-UNREAD-CHAR.