getting "can't open display" when using ssh

**marinara** · August 24th, 2012

I'm used to ssh-ing to my other box, and running GUI apps after setting DISPLAY=:0
The X server is on the box i'm ssh-ing to because i'm not using ssh -X.
With the upgrade to 12.04.1, this stopped working (coincidence?)

I'd like to get this working so I can run programs from ssh.

**sanderj** · August 24th, 2012

Originally Posted by marinara

I'm used to ssh-ing to my other box, and running GUI apps after setting DISPLAY=:0
The X server is on the box i'm ssh-ing to because i'm not using ssh -X.
With the upgrade to 12.04.1, this stopped working (coincidence?)

I'd like to get this working so I can run programs from ssh.

FWIW: The X *server* is the computer having a physical display, so normally the computer in front of you.

DISPLAY=:0 ... ? That points to the same machine. No IP address needed?

And why don't you use 'ssh -X'? That works for me without difficult DISPLAY stuff.

**dozdozez** · August 24th, 2012

May be a question of permissions. Type:

Code:

xhost

This command will tell you which users has access to that computer's X server.
If your user is not listed, add it:

Code:

xhost +SI:localuser:<user>

If you want to grant access to anyone you can do so with xhost +, but this is not recomended for security iissues.

I hope this work for you.

**Lars Noodén** · August 24th, 2012

To followup on what sanderj wrote, you need to have the x-server on the machine on which you will actually do the viewing. Then connect to the remote machine with the -X option. Setting DISPLAY=:0 on the remote machine will cause the program to be displayed on the remote machine itself, if it has an X-server running.

Alternately, instead of using the -X option each time, if you're always going to use X forwarding, you could modify ~/.ssh/config and make an entry for that host:

Code:

Host otherbox
  HostName otherbox.example.edu
  ForwardX11 yes

Either way, you want to leave the DISPLAY variable alone.

**Rexilion** · August 24th, 2012

For me, sometimes

ssh -Y

works. (and no, this is not a lame joke

)

**marinara** · August 24th, 2012

I tried xhost +
Didn't work.
ssh -X works fine. That's not my problem. I want the X server to be on the machine I ssh to. Most likely I installed something stupid, and broke it somehow.