The following works in cron:
* * * * * non-root-user export DISPLAY=:0.0; zenity --info
And displays a zenity dialog on non-root-user's desktop each minute.
But if I do the following:
* * * * * root export DISPLAY=:0.0; zenity --info
it does not work - nothing is shown on 0.0 display. What am I doing wrong?