Wait for reboot

#!/bin/bash

HOST=$1 # Resolvable host name or IP address of remote host.
TIMEOUT=$2

wait_for_reboot() {
    cnt=0
    host=$1

    ping -c 1 -n -w 1 $host | grep "1 received" > /dev/null
    [ $? != 0 ] && status=down || status=up
    [ "$2" == "" ] && timeout=90 || timeout=$2

    echo
    echo -n "Waiting for host \"$host\" to come online: "

    while true; do
        ping -c 1 -n -w 1 $host | grep "0 received" > /dev/null
        result=$?

        echo -n "."
        cnt=$((cnt+1))
        [ $result == 1 ] && sleep 1 || status=down

        [ $result == 1 ] && [ $status == "down" ] && {
            sleep 1
            echo -e "\nHost \"$host\" is back online."
            break
        } || [ $cnt -ge $timeout ] && {
            echo -e "\nRemote host \"$host\" did not reboot.\n"
            break
        }
    done
}

echo
ssh root@$HOST reboot

wait_for_reboot $HOST $TIMEOUT