From eeaf266a7962fd1ee751288bae38a0710b3a6771 Mon Sep 17 00:00:00 2001
From: Dean Troyer <dtroyer@gmail.com>
Date: Thu, 14 Jun 2012 09:11:38 -0500
Subject: [PATCH] Skip screen if not present

Change-Id: I018249c415fa91ca6461a8f9d236767aa57a8fbd
---
 unstack.sh | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/unstack.sh b/unstack.sh
index 7de0d749e5..341270d602 100755
--- a/unstack.sh
+++ b/unstack.sh
@@ -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