--- loncom/homework/lonr.pm	2009/04/18 16:03:17	1.3
+++ loncom/homework/lonr.pm	2009/04/18 23:43:50	1.4
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Interface routines to R CAS
 #
-# $Id: lonr.pm,v 1.3 2009/04/18 16:03:17 www Exp $
+# $Id: lonr.pm,v 1.4 2009/04/18 23:43:50 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -68,6 +68,8 @@ sub blacklisted {
         'dev\.list','dev\.next','dev\.prev','dev\.set',
         'dev\.off','dev\.copy','dev\.print','graphics',
         'library','package','source','sink','objects',
+        'Sys\.','unlink','file\.','on\.exit','error',
+        'q\(\)'
      ) {
 	if ($cmd=~/$forbidden/s) { return 1; }
     }