Index: /trunk/source/level-1/l1-streams.lisp
===================================================================
--- /trunk/source/level-1/l1-streams.lisp	(revision 14436)
+++ /trunk/source/level-1/l1-streams.lisp	(revision 14437)
@@ -5636,6 +5636,7 @@
   
 (defun fd-stream-listen (s ioblock)
-  (declare (ignore s))
-  (unread-data-available-p (ioblock-device ioblock)))
+  (if (interactive-stream-p s)
+    (unread-data-available-p (ioblock-device ioblock))
+    (not (fd-stream-eofp s ioblock))))
 
 (defun fd-stream-close (s ioblock)