How to check if the X11 display manager is installed?

Question

I recently had some problems on sharing the screen on zoom, and I found out that disabling Wayland does the trick. It worked fine for my computer, but when I tried doing this on another computer, I wasn't able to login anymore.

My question is: How can I check if I X11 is installed before disabling Wayland?

Thank you in advance!

Solution

To see if you have x11 installed, simply run this command from a terminal:

dpkg -l | grep xserver-xorg-core

and if you get something like:

ii  xserver-xorg-core                      2:1.19.5-0ubuntu2                                          amd64        Xorg X server - core server

then you have the server installed.

Comments

[Tooniis]

X11 is always installed by default unless you manually removed it. Also this looks like an XY Problem: meta.stackexchange.com/questions/66377/what-is-the-xy-proble‌​m

[marko]

The action of logging in to your graphical environment is generally done by your display manager. If you can specify what distribution you are using and what steps / commands you used to disable Wayland, we might be able to help you. If you want to check whether x11 is installed, run dpkg -l | grep xorg. If you want to check if x11 is currently running (if logged in) then run echo $XDG_SESSION_TYPE. Paste the output.

[Aditzu]

The steps used for disabling wayland was to edit custom.conf file from /etc/dgm3 and uncomment WaylandEnabled = false. For one pc worked fine and echo $XDG_SESSION_TYPE displayed x11, for the other whch failed to disable wayland when executing $XDG_SESSION_TYPE displayed wayland :) On both laptops I have Ubuntu 17.10

[Aditzu]

@Tooniss I said what was my actual problem, I manage to fix it on one laptop with that solution. I don't think that my initial problem is related with the current one. First one was regarding zoom and google handgout, the actual one is regarding x11 display manager.

[marko]

In the section that graphically prompts you to log in (the display manager), there should be an option that allows you to switch between Wayland and Xorg. It will be one of the buttons that you see on the screen. You shouldn't do anything else. Once this i selected, it remembers it.

[Aditzu]

Can we please concentrate to the subject? @marko in 2 hours I have a demo and I cannot make experiments now but I promise right after I will try again and come back with the result. Many thanks!

[Robert Riedl]

@Aditzu, have a look at this question and answers. There are more possibilities than just WaylandEnabled = false

[Aditzu]

@marko you solution worked just well. Selecting Ubuntu on Xorg did the trick without any additional changes. Thank you!

[David Kariuki]

What is the output if it is not installed?