判断进程是否挂掉和重启进程

#！/bin/sh
ps -ef | grep httpd | grep -v grep
if [ $? -ne 0 ]
then
echo "start process......"
else
echo "runing......"
fi

#！/bin/sh
while true;do
ps -ef | grep httpd | grep -v grep
if [ $? -ne 0 ]
then
echo "start process......"
service httpd start
else
echo "runing......"
fi
sleep 20
done