Unable to run .sh script for cron task. Changing background image

Question

I have tried several approaches to fixing this issue, but all I want to do is change the desktop wallpaper when this script is run in cron. Below is what I have so far.

PID=$(pgrep gnome-session)
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)
sudo gsettings set org.gnome.desktop.background picture-uri file:///home/mark/Pictures/Background_Pictures/CAP.jpg

I get the following error when I run this in cron.

(process:17154): dconf-WARNING **: failed to commit changes to dconf: Cannot autolaunch D-Bus without X11 $DISPLAY

I know that part of the problem is that I need to set the DBUS_SESSION_BUS_ADDRESS variable, but I have and it seems to have a valid value.

I'm at a loss as how to accomplish this. Does anyone have a valid solution for this?

Yes. I can't get cron to successfully run the command I specified above without errors. — TheRedCameron, Jan 25 '17 at 05:36
Within System Settings -> Appearance it can cycle through wallpaper I believe. — WinEunuuchs2Unix, Jan 25 '17 at 05:40
I'm trying to set specific times on a particular day when I want the wallpaper to change. Not just like a slideshow. — TheRedCameron, Jan 25 '17 at 05:43
I've attempted without sudo and also with dbus-launch. Neither have worked. — TheRedCameron, Jan 25 '17 at 05:45
Is this a user crontab or a root crontab? Have you tried DISPLAY=:0 gsettings in place of sudo gsettings ? (adjust :0 if that's not the target display) — steeldriver, Jan 25 '17 at 09:51
There are three answers to your question here, one of them using cron script: http://askubuntu.com/questions/835853/how-can-i-get-one-wallpaper-for-each-day-of-the-week — WinEunuuchs2Unix, Jan 25 '17 at 11:13
I just used DISPLAY=:0 instead of sudo and I got this message instead. "(process:24089): dconf-WARNING **: failed to commit changes to dconf: The connection is closed" — TheRedCameron, Jan 27 '17 at 01:51

score 1 · Accepted Answer · answered Jan 28 '17 at 15:44

Found the solution. I used the following script.

PID=$(pgrep gnome-session) 
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-) 
gsettings set org.gnome.desktop.background picture-uri "file:///home/mark/Pictures/Wallpapers/CAP.jpg"

However, the issue was in my cron file. I was using the line

***** root sh /home/mark/scripts/desktop.sh

when it should have been

***** mark sh /home/mark/scripts/desktop.sh

When I ran the script in cron with my own privileges, then I was able to run the script in cron successfully.

Unable to run .sh script for cron task. Changing background image

1 Answers1