if [ "$PING" ]; then
sleep 0
else
sleep 1
if ! "$PING" && ! ls ~/$HOST.log >/dev/null 2>&1; then
echo "$HOST ($IP) down at $DATE" | mail -s "$HOST down" $MAIL
touch ~/$HOST.log
fi
fi
if ls ~/$HOST.log >/dev/null 2>&1 && "$PING" ; then
echo "$HOST ($IP) up at $DATE" | mail -s "$HOST up" $MAIL
rm ~/$HOST.log >/dev/null 2>&1
fi