Merge pull request #943 from agx/env-vars

Document env vars used by wlroots/rootston

docs/env_vars.md

@@ -0,0 +1,20 @@
+wlroots reads these environment variables
+
+wlroots specific
+----------------
+* *WLR_DRM_DEVICES*: specifies the DRM devices (as a colon separated list) instead of auto probing them. The first existing device in this list is considered the primary DRM device.
+* *WLR_DRM_NO_ATOMIC*: set to 1 to use legacy DRM interface instead of atomic mode setting
+* *WLR_LIBINPUT_NO_DEVICES*: set to 1 to not fail without any input devices
+* *WLR_WL_OUTPUTS*: when using the wayland backend specifies the number of outputs
+* *WLR_X11_OUTPUTS*: when using the X11 backend specifies the number of outputs
+
+rootston specific
+------------------
+* *XKB_DEFAULT_RULES*, *XKB_DEFAULT_MODEL*, *XKB_DEFAULT_LAYOUT*, *XKB_DEFAULT_VARIANT*, *XKB_DEFAULT_OPTIONS*: xkb setup
+
+generic
+-------
+* *DISPLAY*: if set probe X11 backend in *wlr_backend_autocreate*
+* *WAYLAND_DISPLAY*, *_WAYLAND_DISPLAY*, *WAYLAND_SOCKET*: if set probe Wayland backend in *wlr_backend_autocreate*
+* *XCURSOR_PATH*: directory where xcursors are located
+* *XDG_RUNTIME_DIR*: used to store non persistent temporary files