I find it easier to use pidof
I'm using bash:
if [ ! "$(pidof mythfrontend)" ]
then
echo "Mythfrontend is not started. Starting Mythfrontend..."
sleep 3
DISPLAY=:0 xset -dpms
ulimit -c unlimited
DISPLAY=:0 mythfrontend --syslog local7 -q 2>&1 &
else
echo "Mythfrontend is already started."
fi
Doug