https://bbs.archlinux.org/viewtopic.php?id=123701 https://unix.stackexchange.com/questions/193827/what-is-display-0 https://askubuntu.com/questions/85612/how-to-call-zenity-from-cron-script https://askubuntu.com/questions/235310/how-do-i-run-a-simple-zenity-script-after-disconnecting-from-wifi `DISPLAY=:0` `su t510599 -c 'zenity --info --text "test" --display=:0.0'`