Issue Running GUI Exec Binding Command


I’m trying to make openHAB show the openHAB log, via MultiTail (the colorful one that shows both the events.log and openhab.log) on the screen of the server/machine running openHAB.

I have successfully made a shell script as well as an xfce desktop launcher file that both successfully open a new terminal window and show the MultiTail log. My script to accomplish this is:

xdotool key Escape && sleep 1 && xfce4-terminal --maximize && sleep 1 && xdotool type 'openhablog' && sleep .5 && xdotool key 'Return' && sleep .5 && xdotool key ctrl+minus

The above script wakes up the screen, opens a maximized new terminal window, runs the “openhablog” command to launch MultiTail and then zooms out once so I can properly see the text on my screen.

I have set the proper permissions, etc. to make the Exec Binding properly run the script, and it does.
However, I receive an error, I’m guessing because the Exec Binding doesn’t allow for GUI/X-session or whatever it’s called applications to run (hoping this isn’t the case).

Here is my error:
[INFO ] [e.smarthome.model.script.openHAB log] - Error: Can’t open display: (null)
Failed creating new xdo instance

I have used a third-party tool (TriggerCMD) in the past, but I don’t like using it and would like to accomplish my task directly using openHAB and the Exec Binding.

How can I make this work? Thank you!!

Commands run in the exec binding do not have a shell, hence no display. Some people call a shell script using the exec binding. I do not know if that would work in this situation.


For X programs to run on the right display a variable called DISPLAY needs to be set.
Some information is given here.
As multiple users can share a computer with different displays a security token is used to only allow the owner of the DISPLAY connect to it ( ).
You can try to either disable the security by using xhost+ in the environment of the target display or try to run your command via a ssh tunnel ( connect from openhab user to the user that owns the display ).


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Actually they need a shell to set the display, hence my suggestion of using a shell script.

Those discussions are well outside the topic of this thread though. They are more appropriate in a Linux or UNIX forum. Yes, I was a UNIX Administrator for many years.

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