@@ -25,9 +25,12 @@ if [[ "$1" == "--all" ]]; then

 fi

 # Shut down devstack's screen to get the bulk of OpenStack services in one shot

-SESSION=$(screen -ls | grep "[0-9].stack" | awk '{ print $1 }')

-if [[ -n "$SESSION" ]]; then

-    screen -X -S $SESSION quit

+SCREEN=$(which screen)

+if [[ -n "$SCREEN" ]]; then

+    SESSION=$(screen -ls | awk '/[0-9].stack/ { print $1 }')

+    if [[ -n "$SESSION" ]]; then

+        screen -X -S $SESSION quit

+    fi

 fi

 # Swift runs daemons