xwd: unable to open display 'localhost:15.0'

laredotornado · 07-05-2011, 09:10 AM

Hi,

I'm SSH'ed in to my Ubuntu 11.04 machine and trying to take a screen shot of a virtual display where I'm running (hopefully) Firefox. I get the error

Code:

selenium@selenium:~$ xwd -display localhost:15.0 -out ~/desk.xwd -root
xwd:  unable to open display 'localhost:15.0'

I know that I have displayed the right display variable because in an earlier script that runs at system bootup I have

Code:

        export DISPLAY=localhost:15.0
        /usr/bin/Xvfb :15 -ac -screen 0 1024x768x16 &

Anyway, looking for any hints to help me take a screen shot. Thanks, - Dave

smallpond · 07-07-2011, 01:18 PM

This doesn't work for me either on most remote logins, even tho it always works when you are on the local display. I've never tracked down the cases where it works or doesn't but I suspect it is to do with default DISPLAY variable and X forwarding.

I can get it to work from Cygwin on my Windows PC if I do:

Code:

ssh -Y smallpond
xwd -out foo.xwd

Where smallpond is my Fedora 15 linux box. Note that I did not specify display, I let ssh set its default values. I get the crosshair cursor and can click on a smallpond window and it will generate the xwd file.