-insmod loop > /dev/null 2>&1
-if [ "$LOOPDEV" -a "`losetup $LOOPDEV 2> /dev/null`" ]; then
- echo "It appears that $LOOPDEV is in use. Unable to continue" 1>&2
- echo "You need to clean up $LOOPDEV (via cleanup.sh),"
- echo "or you can change which device is used in demos/config.sh" 1>&2
- # undo previous
- [ "$TMPFILE" ] && rm $TMPFILE
- exit 2
+if [ "$LOOPDEV" ]; then
+ insmod loop > /dev/null 2>&1
+ if [ -a "`losetup $LOOPDEV 2> /dev/null`" ]; then
+ echo "It appears that $LOOPDEV is in use. Unable to continue" 1>&2
+ echo "You need to clean up $LOOPDEV (via cleanup.sh),"
+ echo "or you can change which device is used in demos/config.sh" 1>&2
+ # undo previous
+ [ "$TMPFILE" ] && rm $TMPFILE
+ exit 2
+ fi
+ losetup $LOOPDEV $TMPFILE