[Ubuntu] Spawning graphical apps on desktop via remote shell

cheeken · 01-19-2009, 10:39 AM

I would like to remotely ssh into my Ubuntu box and run applications which require a display (a la gedit) through my ssh console and have those applications spawn on the Ubuntu desktop (not on the machine I am ssh'ing from).

I have achieved success in doing this on Redhad and SLED (running Xvnc) by assigning the DISPLAY environment variable to the appropriate value (:0.0, for example). However, Ubuntu presents other difficulties (it uses vino/gnome, not Xvnc) which seem to be tied to xauth.

After setting DISPLAY and issuing a command like gedit, I am returned the following error. (On my Redhat and SLED systems, simply setting DISPLAY to the appropriate value is all I have to do.)

Code:

myuser@myhost:~$ gedit
Invalid MIT-MAGIC-COOKIE-1 keycannot open display:
Run 'gedit --help' to see a full list of available command line options.

If I peek at my desktop's environment - specifically the XAUTHORITY variable - and apply that same value to my shell session, the command runs without errors and the gedit window spawns on the desktop. But is there a way to figure out the value of XAUTHORITY without looking at my desktop session? Moreover, is there a better approach to this problem than trying to set DISPLAY and XAUTHORITY to the appropriate values?

Any thoughts are greatly appreciated. Thanks!

CITguy · 02-04-2009, 01:24 AM

Have you tried using the command ssh rather than using vnc? There is an "-X" option that allows you to redirect X to the local machine.

SYNTAX:

Code:

ssh <user>@<machine name or IP address> -X

EXAMPLE:
If I (foo) wanted to ssh into my desktop (Achilles: 192.168.1.20), I would use one of the following commands:

Code:

foo@localhost:~$ ssh foo@Achilles -X
or
foo@localhost:~$ ssh foo@192.168.1.20 -X

Then, once I'm connected to Achilles, I run the "gedit" command to open the application on my local machine.

Code:

foo@Achilles:~$ gedit

jschiwal · 02-04-2009, 01:27 AM

Is your local terminal on a Linux or windows machine. If you run "ssh -X" from Linux, ssh will handle xauth and the DISPLAY name for you. If you are using windows you can install Cygwin/X and use ssh the same way.

CITguy · 02-04-2009, 01:47 AM

In my instructions, I am referring to the local machine as a Linux box.
As far as Windows goes, I am not familiar with opening X apps locally.

blackhole54 · 02-04-2009, 03:23 AM

Uh, the OP wants to open the application on the remote machine, not on the local machine:

Quote:

Originally Posted by cheeken

... and have those applications spawn on the Ubuntu desktop (not on the machine I am ssh'ing from).

On my (older) Ubuntu system, $XAUTHORITY just points to the ~/.Xauthority file. Are you saying on yours it contains the actual value of the cookie and there is no ~/.Xauthority file? If so, I think you could have a script write that value to a file when you graphically log in to your Ubuntu box. (Make sure you think about security implications. And certainly make sure such a file is readable only by the user.) Then you can read that file and set the variable when ssh in. In Gnome you can set the script which writes the file to run from:

System ->Preferences -> Sessions -> Startup Programs

jschiwal · 02-04-2009, 05:00 AM

What use is a graphical program running remotely if you can't control it?
If that is truly what you want, then you can precede the command with DISPLAY=':0.0'. Example:
DISPLAY=':0.0' gedit