--- loncom/homework/lonr.pm	2009/04/18 13:18:58	1.2
+++ loncom/homework/lonr.pm	2009/04/18 16:03:17	1.3
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Interface routines to R CAS
 #
-# $Id: lonr.pm,v 1.2 2009/04/18 13:18:58 www Exp $
+# $Id: lonr.pm,v 1.3 2009/04/18 16:03:17 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -61,11 +61,13 @@ sub rreply {
 sub blacklisted {
     my ($cmd)=@_;
     foreach my $forbidden (
-        'read\.table','scan','plot','X11','windows','quartz',
+        'read','write','scan','save','socket','connections',
+        'open','close',
+        'plot','X11','windows','quartz',
         'postscript','pdf','png','jpeg',
         'dev\.list','dev\.next','dev\.prev','dev\.set',
-        'dev\.off','dev\.copy','dev\.print','graphics\.off',
-        'library','package','source','sink','objects'
+        'dev\.off','dev\.copy','dev\.print','graphics',
+        'library','package','source','sink','objects',
      ) {
 	if ($cmd=~/$forbidden/s) { return 1; }
     }