How to call zenity from cron script?

Found answer here. Add to ~/.bashrc:

xhost local:$USER > /dev/null

and then use zenity in script evoked by cron like this:

zenity --error --text='Something very bad has happened!' --display=:0.0

adding --display=:0.0 is what's important

To run a GUI command on cron, you'll have to tell cron what display the program should use. For that you use:export DISPLAY=:0

For a zenity notification each 30 minutes, edit with crontab -e and set a job like:

*/30 *  * * *  export DISPLAY=:0 && /somedirectory/your_zenity_script.sh

Detailed how to: link

There's another possible solution if you want it to work regardless of username, by finding the active user of the X display, using ConsoleKit (the command ck-list-sessions). Assuming the below script is run as root, it will show a zenity message to the current active user on your computer:

#!/bin/bash
ACTIVE=$(ck-list-sessions | awk -F' = ' '
    function f(){if(A=="TRUE"){P=U"\t"D;gsub("'"'"'","",P);print P}}
    $1=="\tunix-user"{U=$2} 
    $1=="\tx11-display"{D=$2} 
    $1=="\tactive"{A=$2} 
    END{f()} /^[^\t]/{f()}
')
USERID=${ACTIVE%    *} # tab
USERNAME=$(getent passwd $USERID|cut -f1 -d':')
DISPLAY=${ACTIVE#*  } # tab

DISPLAY="$DISPLAY" su $USERNAME -c "zenity --error --text='Something very bad has happened!'"

The little awk script is just for parsing ck-list-sessions and outputting the username and display of the user that is active (could also require that it's a local connection if you want to exclude ssh -X users, if you want).

(I use this in a backup script that runs on plugging in a USB drive.)

How to call zenity from cron script?

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