wlseeds/docs/env_vars.md

wlroots reads these environment variables

# wlroots specific

* *WLR_BACKENDS*: comma-separated list of backends to use (available backends:
  libinput, drm, wayland, x11, headless, noop)
* *WLR_NO_HARDWARE_CURSORS*: set to 1 to use software cursors instead of
  hardware cursors
* *WLR_XWAYLAND*: specifies the path to an Xwayland binary to be used (instead
  of following shell search semantics for "Xwayland")
* *WLR_RENDERER*: forces the creation of a specified renderer (available
  renderers: gles2, pixman, vulkan)
* *WLR_RENDER_DRM_DEVICE*: specifies the DRM node to use for
  hardware-accelerated renderers.

## DRM backend

* *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_DRM_NO_MODIFIERS*: set to 1 to always allocate planes without modifiers,
  this can fix certain modeset failures because of bandwidth restrictions.

## Headless backend

* *WLR_HEADLESS_OUTPUTS*: when using the headless backend specifies the number
  of outputs

## libinput backend

* *WLR_LIBINPUT_NO_DEVICES*: set to 1 to not fail without any input devices

## Wayland backend

* *WLR_WL_OUTPUTS*: when using the wayland backend specifies the number of outputs

## X11 backend

* *WLR_X11_OUTPUTS*: when using the X11 backend specifies the number of outputs

## gles2 renderer

* *WLR_RENDERER_ALLOW_SOFTWARE*: allows the gles2 renderer to use software
  rendering

# Generic

* *DISPLAY*: if set probe X11 backend in `wlr_backend_autocreate`
* *WAYLAND_DISPLAY*, *WAYLAND_SOCKET*: if set probe Wayland backend in
  `wlr_backend_autocreate`
* *XCURSOR_PATH*: directory where xcursors are located
* *XDG_SESSION_ID*: if set, session ID used by the logind session
Document env vars used by wlroots 7 years ago			`wlroots reads these environment variables`

Add FreeRDP backend for remote desktop support 6 years ago			`# wlroots specific`

backend: allow multiple backends in WLR_BACKENDS 7 years ago			`* WLR_BACKENDS: comma-separated list of backends to use (available backends:`
Drop RDP backend Users interested in remote access to wlroots compositors should use wayvnc: https://github.com/any1/wayvnc 5 years ago			`libinput, drm, wayland, x11, headless, noop)`
output: introduce WLR_NO_HARDWARE_CURSORS 6 years ago			`* WLR_NO_HARDWARE_CURSORS: set to 1 to use software cursors instead of`
			`hardware cursors`
xwayland: introduce WLR_XWAYLAND for specifying which Xwayland to use When debugging Xwayland-related issues, a common first step in debugging has been to ask the reporter to move their real Xwayland to /usr/bin/Xwayland.bin, and create a shell script starting Xwayland with extra arguments under the original /usr/bin/Xwayland location. Introducing a `WLR_XWAYLAND` environment variable makes this less invasive, by allowing the user to swap out Xwayland without resorting to global system changes (or source patches). 4 years ago			`* WLR_XWAYLAND: specifies the path to an Xwayland binary to be used (instead`
			`of following shell search semantics for "Xwayland")`
render: introduce WLR_RENDERER in wlr_renderer_autocreate_with_drm_fd This env var forces the creation of a specific renderer. If no renderer is specified, the function will try to create all of the renderers one by one until one is created successfuly. 4 years ago			`* WLR_RENDERER: forces the creation of a specified renderer (available`
docs: mention WLR_RENDERER=vulkan. This option was added with commit 8e346922508aa3eaccd6e12f2917f6574f349843. 3 years ago			`renderers: gles2, pixman, vulkan)`
render: introduce WLR_RENDER_DRM_DEVICE This env var allows to override the DRM node used by the GLES2 and Vulkan renderers. It's especially useful to select a DRM node when running with the headless backend. References: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/2656 3 years ago			`* WLR_RENDER_DRM_DEVICE: specifies the DRM node to use for`
			`hardware-accelerated renderers.`
Document env vars used by wlroots 7 years ago
docs: establish one section per backend 5 years ago			`## DRM backend`

			`* 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`
backend/drm: add env variable to disable modifiers In some cases modesets fail if the planes are initialized with modifiers. Since in this case possibly all planes need to reinitialized, which is not possible in the current wlroots design, add an environment variable for affected users. 5 years ago			`* WLR_DRM_NO_MODIFIERS: set to 1 to always allocate planes without modifiers,`
			`this can fix certain modeset failures because of bandwidth restrictions.`
docs: establish one section per backend 5 years ago
			`## Headless backend`
Add FreeRDP backend for remote desktop support 6 years ago
			`* WLR_HEADLESS_OUTPUTS: when using the headless backend specifies the number`
			`of outputs`

docs: establish one section per backend 5 years ago			`## libinput backend`

			`* WLR_LIBINPUT_NO_DEVICES: set to 1 to not fail without any input devices`

			`## Wayland backend`
Add FreeRDP backend for remote desktop support 6 years ago
			`* WLR_WL_OUTPUTS: when using the wayland backend specifies the number of outputs`

docs: establish one section per backend 5 years ago			`## X11 backend`
Add FreeRDP backend for remote desktop support 6 years ago
			`* WLR_X11_OUTPUTS: when using the X11 backend specifies the number of outputs`

render/egl: fail to create wlr_egl on software renderer The creation of `wlr_egl` will fail is the device extension EGL_MESA_device_software is defined. The creation process is allowed to continue only if the environment variable `WLR_RENDERER_ALLOW_SOFTWARE` is defined to the value 1. 4 years ago			`## gles2 renderer`

			`* WLR_RENDERER_ALLOW_SOFTWARE: allows the gles2 renderer to use software`
			`rendering`

Add FreeRDP backend for remote desktop support 6 years ago			`# Generic`

docs/env_vars: document seatd session 4 years ago			* DISPLAY: if set probe X11 backend in `wlr_backend_autocreate`
docs/env_vars: _WAYLAND_DISPLAY isn't used anymore 4 years ago			`* WAYLAND_DISPLAY, WAYLAND_SOCKET: if set probe Wayland backend in`
			`wlr_backend_autocreate`
Document env vars used by wlroots 7 years ago			`* XCURSOR_PATH: directory where xcursors are located`
docs: document XDG_SESSION_ID 5 years ago			`* XDG_SESSION_ID: if set, session ID used by the logind session`