@comment -*- Mode:CommonLISP; Package:USER -*-

@lisp

(defun big-endian-bytes (array &rest bytes)
  "Combine bytes into an integer, most significant come first"
  (do ((number 0 (+ (* number 256) (aref array (car l))))
       (l bytes (cdr l)))
      ((null l) number)))

(defvar *last-bogus-buffer* nil)

(defun get-imagen-status (&optional (printer si:*default-printer*) &aux address)
  (assert (setq address (ip:parse-internet-address printer))
	  (printer)
	  "~A is not a valid Internet host name or address" printer)
  (with-open-file (stream (format nil "UDP-HOST:~A.IMAGEN" address))

    (let ((buff (udp:get-udp-buffer)))
      (fillarray buff '(0.))
      (funcall stream :write-packet buff)
      (send stream :force-output)
      (dotimes (j 12.)
	(if (and (funcall stream :listen)
		 (funcall stream :read-packet buff)
		 (not (zerop (array-active-length buff))))
	    (return)
	  (process-sleep 60. "Waiting for Imagen")))
      (cond
	((null buff)
	 (format t "Imagen status not available"))
	((zerop (array-active-length buff))
	 (warn "Null UDP packet received")
	 ;;Help for debugging:
	 (setq *last-bogus-buffer* buff)
	 nil)
	(:else
	   (format t "~&~A"
		   (substring buff
			      (big-endian-bytes buff 16 1)
			      (+ (big-endian-bytes buff 16 1)
				 (big-endian-bytes buff 18 19)))))))))

@end(lisp)