xwayland display variable

[Scott Anderson]

On 1/05/19 11:30 pm, Damian Ivanov wrote:
> Hello,
> 
> Is it somewhere documented how Xwayland applications are choosing
> which compositor to display on? e.g 2 compostiors (1 nested or on
> another VT)
> wayland-0 and wayland-1
> export WAYLAND_DISPLAY=wayland-1
> GDK_BACKEND=x11 gedit //starts on wayland-0
> 
> If it's not documented how to do it?
> Thank you in advance!
> 
> Damian

Hi,

X programs running through Xwayland connect to it with the exact same 
mechanism they use for connecting to a normal X server, which usually 
means looking at the DISPLAY environment variable.

Each Wayland compositor would start and manage their own separate 
Xwayland server, and would take their own DISPLAY values (e.g. 
DISPLAY=:0, DISPLAY=:1).

In the case of the WAYLAND_DISPLAY=wayland-1 compositor's X server takes 
DISPLAY=:1, you'd run that command like:

   GDK_BACKEND=x11 DISPLAY=:1 gedit

So setting WAYLAND_DISPLAY isn't technically needed, but it's still a 
good idea to set it too, because it can have an effect on other 
processes which your command can start.

Scott