shell后台进度条

#!/bin/sh

function progress()
{
        while true
        do
                echo -n "."
                sleep 1
        done
}

progress &

childpid=$!

num=0
while [ $num -lt 3 ]
do
        sleep 1
        num=`expr $num + 1`
done

kill $childpid

echo ""
echo "System will be reboot"