vi /path/to/message.sh #!/bin/bash PID=$(pgrep gnome-session) dbus=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-) export DBUS_SESSION_BUS_ADDRESS=$dbus notify-send -u critical "$1" crontab: `0 * * * * /path/to/message.sh "my message"`