I have previously patched netsurf and a couple of test programs to automatically select
the appropriate nsfb backend using getenv() if it is not provided as an arg, but it may be
useful to have this as the default behavior.
the following env variables are set:
Wayland -> WAYLAND_DISPLAY
xcb -> DISPLAY
linux framebuffer -> FRAMEBUFFER (and possibly isatty()?)
vnc -> check port 5900?
able -> no idea
For the ones I'm familiar with the order should be wayland,xcb,linuxfb,sdl but I am
less familiar with able and vnc. I assume Able should fall somewhere around the linuxfb
and vnc should either be first (by checking port 5900) or required as an arg.