============== error message ====================

(zenity:14713): Gtk-WARNING **: GTK+ module /usr/lib/gtk-2.0/modules/libcanberra-gtk-module.so cannot be loaded.
GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported.
Gtk-Message: Failed to load module "canberra-gtk-module"

=============== the script =======================
#!/bin/bash

if [ -z "$1" ]
then
    minutes=60
else
    minutes=$1
fi

let "timeout=minutes * 60"

counter=0

zenity --info --text "Next alert in $minutes minutes ($timeout seconds)" --title "Decub Launched"

exec 3> >(zenity --notification --listen)

echo "icon:/home/xh/.icons/decubb_21.png" >&3

while true ; do
    echo "tooltip: DECUB Minutes Elapsed: $counter" >&3
    sleep 60

    let counter++
    echo $counter

    if [ $counter -eq $minutes ]
    then
        counter=0
        zenity --question --text="Decub time: `date '+%A, %k:%M'`" --title="Decub Trigger" --ok-label="Sleep again for $minutes minutes ($timeout seconds)" --cancel-label="Shut down..."
        if [ $? = 1 ]
        then
            zenity --question --text='Really shut down now?' --ok-label='sudo shutdown -h now' --cancel-label='Keep working' && sudo shutdown -h now
            #exit
            #exec 3>&-
        fi
    fi
done