On Tuesday 05 of February 2019 00:38:11 Felix Miata wrote:
> Sl�vek Banko composed on 2019-02-04 23:02 (UTC+0100):
> > Felix Miata wrote:
> >> https://www.maketecheasier.com/take-screenshot-of-login-screen-linux
> >>/ is the closest I have found to instructions to use ImageMagick to
> >> get one, but tdm seems to be different from lightdm and gdm such
> >> that I can't figure out what to change. I tried logging in and
> >> grepping XAUTHORITY from set, but it apparently cannot be found
> >> there.
> >>
> >> I want a fullscreen screenshot that has the integrated default
> >> theme's menu expanded to show the selection of session types. Can
> >> anyone here help?
> >
> > You can search in: /var/run/xauth/
>
> I don't see any connection. e.g. in Stretch I see (only):
>
> 	/var/run/xauth/A:0-TZtcAa
>
> 44 binary bytes owned by root and containing string
> "MIT-MAGIC-COOKIE-1". On openSUSE it's the same except for the last 6
> characters of the filename. How can that be translated to
>
> /var/lib/gdm/$DISPLAY.Xauth
> or
> /var/run/lightdm/root/$DISPLAY
>
> ???
>
> Would it be simply
>
> 	/var/run/xauth/$DISPLAY
>
> or something else?
>
> I tried putting
>
> 	#! /bin/bash
> 	chvt 7
> 	DISPLAY=:0 XAUTHORITY=/var/run/xauth/$DISPLAY xwd -root
>
> in the script, but the resulting output image is always 0 bytes, and
> error messages:
>
> 	No protocol specified
> 	xwd: unable to open display ':0'
>
> I tried on Tubuntu 18.04/14.1 with same result.

First, for XAUTHORITY should be: XAUTHORITY=/var/run/xauth/A${DISPLAY}-*

Second, I do not see in the man page that xwd would accept the environment 
variable XAUTHORITY or option like -auth or -xauth.

Cheers
-- 
Sl�vek