diff --git a/res/ndn b/res/ndn
index fd492de..5803fbe 100755
--- a/res/ndn
+++ b/res/ndn
@@ -1,3 +1,13 @@
 #!/bin/sh
 
-/Applications/NDN.app/Contents/Resources/ndn/bin/"$@"
+if [[ $# -eq 0 ]] ; then
+    echo ERROR: No command specified
+    echo
+    echo Available commands:
+    for command in $(ls /Applications/NDN.app/Contents/Resources/platform/bin/ 2>/dev/null); do
+        echo "  $command"
+    done
+    exit 1
+fi
+
+/Applications/NDN.app/Contents/Resources/platform/bin/"$@"