Wayland: Difference between revisions

Latest revision as of 19:08, 18 May 2024

Wayland is a new display protocol that aims to replace X11.

Multiple compositor implementations exist, including Sway, Mutter (GNOME's compositor) and Kwin (KDE's compositor). A more exhaustive list is available in the ArchWiki.

XDG_RUNTIME_DIR

As per the protocol spec, Wayland compositors require the XDG_RUNTIME_DIR variable to be set. There are a few ways to configure create a temporary runtime directory and export this variable:

elogind can do this and also export other XDG environment variables automatically for each session.
pam-rundir can handle this for logins. To use this PAM is required.
mkrundir is an executable that can be used to initialise the runtime directory explicitly by each user.
Setting it up manually (see below).

Note that this variable MUST be initialised before the Wayland compositor, and also before the D-Bus session instance is started.

Configuring XDG_RUNTIME_DIR manually

Generally, care should be taken when configuring the XDG_* variables manually as this configuration may have errors or conflict with other utilities that do this automatically.

On a system that's not using elogind nor any pam module that handles this, the XDG_RUNTIME_DIR can be initialised manually. The easiest approach is by adding a snippet like this one to shell init scripts (e.g.: ~/.profile):

Contents of ~/.profile

if [ -z "$XDG_RUNTIME_DIR" ]; then
	XDG_RUNTIME_DIR="/tmp/$(id -u)-runtime-dir"

	mkdir -pm 0700 "$XDG_RUNTIME_DIR"
	export XDG_RUNTIME_DIR
fi

@@ Line 1: / Line 1: @@
-Wayland is a new display protocol that aims to replace X11.
+[https://en.wikipedia.org/wiki/Wayland%20(protocol) Wayland] is a new display protocol that aims to replace X11.
+Multiple compositor implementations exist, including [[Sway]], [https://en.wikipedia.org/wiki/Mutter%20(software) Mutter] ([[GNOME]]'s compositor) and [https://en.wikipedia.org/wiki/KWin Kwin] ([[KDE]]'s compositor). [https://wiki.archlinux.org/title/Wayland#Compositors A more exhaustive list is available in the ArchWiki].
 == XDG_RUNTIME_DIR ==
-Weston and other compositors require the XDG_RUNTIME_DIR variable to be set. Simply save the following script in /etc/profile.d/xdg_runtime_dir.sh and re-login to have it set up properly.
- if test -z "${XDG_RUNTIME_DIR}"; then
+As per the protocol spec, Wayland compositors require the <code>XDG_RUNTIME_DIR</code> variable to be set. There are a few ways to configure create a temporary runtime directory and export this variable:
-   export XDG_RUNTIME_DIR=/tmp/$(id -u)-runtime-dir
-   if ! test -d "${XDG_RUNTIME_DIR}"; then
-     mkdir "${XDG_RUNTIME_DIR}"
-     chmod 0700 "${XDG_RUNTIME_DIR}"
-   fi
- fi
+* [[elogind]] can do this and also export other XDG environment variables automatically for each session.
+* {{pkg|pam-rundir}} can handle this for logins. To use this [[PAM]] is required.
+* [https://git.sr.ht/~whynothugo/mkrundir mkrundir] is an executable that can be used to initialise the runtime directory explicitly by each user.
+* Setting it up manually ([[#Configuring_XDG_RUNTIME_DIR_manually|see below]]).
-This code was taken from Weston's build instructions. Only ${UID} (not present on Alpine Linux) has been replaced with $(id -u).
+Note that this variable MUST be initialised before the Wayland compositor, and also before the D-Bus session instance is started.
+=== Configuring XDG_RUNTIME_DIR manually ===
+Generally, care should be taken when configuring the <code>XDG_*</code> variables manually as this configuration may have errors or conflict with other utilities that do this automatically.
+On a system that's not using elogind nor any pam module that handles this, the <code>XDG_RUNTIME_DIR</code> can be initialised manually. The easiest approach is by adding a snippet like this one to shell init scripts (e.g.: {{Path|~/.profile}}):
+{{Cat|~/.profile|<nowiki>if [ -z "$XDG_RUNTIME_DIR" ]; then
+	XDG_RUNTIME_DIR="/tmp/$(id -u)-runtime-dir"
+	mkdir -pm 0700 "$XDG_RUNTIME_DIR"
+	export XDG_RUNTIME_DIR
+fi
+</nowiki>}}
+== See also ==
+* [https://wiki.archlinux.org/title/Wayland Wayland - Arch Wiki]
+* [https://wiki.gentoo.org/wiki/Wayland Wayland - Gentoo Wiki]
+* [https://en.wikipedia.org/wiki/Wayland_(protocol) Wayland (protocol) - Wikipedia]
 [[Category:Desktop]]
+[[Category:Wayland]]