Ping HOSTNAME and if it's down then WOL it and send a notification mail to the admin.

supervise-host.sh

#!/bin/sh
 
if [ $# -ne 2 ]; then
    echo "Usage: $0 HOSTNAME NOTIFICATION-SCRIPT-URL"
    echo "Ping HOSTNAME and if it's down then WOL it and send a notification mail to the admin."
    echo "NOTIFICATION-SCRIPT-URL?host=HOSTNAME will be fetched to send the actual mail."
    echo "Example: $0 mybox http://mydomain.com/notifyme.php"
    exit
fi
 
watched_host=$1
notification_script_url=$2
 
watched_host_down_file=/tmp/$watched_host.down
 
ping -c 1 -W 1 $watched_host > /dev/null
is_watched_host_alive=$?
if [ $is_watched_host_alive -eq 0 ]; then
    if [ -e $watched_host_down_file ]; then
        echo "$watched_host has been woken up"
        rm -f $watched_host_down_file
        wget $notification_script_url?host=$watched_host
    fi
else
    echo "waking up $watched_host"
    touch $watched_host_down_file
    wol $watched_host
fi