I am currently working with C and SDL2, and I need to know whether Wayland is currently used as the windowing system (Obviously because I want to use Wayland, but SDL2 defaults to Xwayland). While SDL_VIDEODRIVER=wayland does work, it won't work if you are in X11, saying that the video driver is unavailable. So, what I am looking for, is a low-level way of getting the current windowing system (Possibly by asking the compositor?) on GNU/Linux. It also needs to be unmodifiable, that is, no application or user will be able to change it unless the session ends.

CodePudding user response：

Initialize SDL with no subsystem via SDL_Init(0) then ask SDL to connect to whatever Wayland session is running via SDL_VideoInit("wayland"); if that call succeeds you're good to go with the usual SDL_Init(SDL_INIT_EVERYTHING) & window creation.

Though for more robustness you should iterate over the SDL_GetNumVideoDrivers()/SDL_GetVideoDriver() string list to verify the SDL install in use was even built with Wayland support.

See the test program here for video driver enumeration & testing.