xinit

From Wikipedia:

The xinit program allows a user to manually start an Xorg display server. The startx(1) script is a front-end for xinit(1).

xinit is typically used to start window managers or desktop environments. While you can also use xinit to run GUI applications without a window manager, many graphical applications expect an EWMH compliant window manager. Display managers start Xorg for you and generally source xprofile.

Installation

Install the xorg-xinit package.

Configuration

xinit and startx take an optional client program argument, see #Override xinitrc. If you do not provide one they will look for ~/.xinitrc to run as a shell script to start up client programs.

xinitrc

~/.xinitrc is handy to run programs depending on X and set environment variables on X server startup. If it is present in a user's home directory, startx and xinit execute it. Otherwise startx will run the default /etc/X11/xinit/xinitrc.

Note: Xinit has its own default behaviour instead of executing the file. See xinit(1) for details.

This default xinitrc will start a basic environment with Twm, xorg-xclock and Xterm (assuming that the necessary packages are installed). Therefore, to start a different window manager or desktop environment, first create a copy of the default xinitrc in your home directory:

$ cp /etc/X11/xinit/xinitrc ~/.xinitrc

Then edit the file and replace the default programs with desired commands. Remember that lines following a command using exec would be ignored. For example, to start xscreensaver in the background and then start openbox, use the following:

~/.xinitrc

...
xscreensaver &
exec openbox-session

Note: At the very least, ensure that the last if block in /etc/X11/xinit/xinitrc is present in your ~/.xinitrc file to ensure that the scripts in /etc/X11/xinit/xinitrc.d are sourced.

Long-running programs started before the window manager, such as a screensaver and wallpaper application, must either fork themselves or be run in the background by appending an & sign. Otherwise, the script would halt and wait for each program to exit before executing the window manager or desktop environment. Note that some programs should instead not be forked, to avoid race bugs, as is the case of xrdb. Prepending exec will replace the script process with the window manager process, so that X does not exit even if this process forks to the background.

xserverrc

The xserverrc file is a shell script responsible for starting up the X server. Both startx and xinit execute ~/.xserverrc if it exists, startx will use /etc/X11/xinit/xserverrc otherwise.

See Xserver(1) for a list of all command line options.

Passing virtual terminal number

In order to maintain an authenticated session with logind and to prevent bypassing the screen locker by switching terminals, Xorg has to be started on the same virtual terminal where the login occurred [1]. For this purpose, Xorg needs to be passed the number of the current virtual terminal.

If you are invoking startx, nothing more needs to be done – it contains logic to compute and pass the virtual terminal number to Xorg.

In other cases, e.g. if you are running xinit, it is recommended to specify vt$XDG_VTNR in the ~/.xserverrc file:

~/.xserverrc

#!/bin/sh

exec /usr/bin/Xorg -nolisten tcp "$@" vt$XDG_VTNR

Tip: -nolisten local can be added after -nolisten tcp to disable abstract sockets of X11 to help with isolation. There is a quick background on how this potentially affects X11 security.

Note: To re-enable redirection of the output from X session into the Xorg log file, add the -keeptty option. See Xorg#Session log redirection for details.

Usage

To run Xorg as a regular user, issue:

$ startx

Or if #xserverrc is configured:

$ xinit -- :1

Note: xinit does not handle multiple displays when another X server is already started. For that you must specify the display by appending -- :display_number, where display_number is 1 or more.

Your window manager (or desktop environment) of choice should now start correctly.

To quit X, run your window manager's exit function (assuming it has one). If it lacks such functionality, run:

$ pkill -15 Xorg

Note: pkill will kill all running X instances. To specifically kill the window manager on the current virtual terminal, run:

$ pkill -15 -t tty"$XDG_VTNR" Xorg

Tips and tricks

Override xinitrc

If you have a working ~/.xinitrc but just want to try other window manager or desktop environment, you can run it by issuing startx followed by the path to the window manager, for example:

$ startx /usr/bin/i3

If the binary takes arguments, they need to be quoted to be recognized as part of the first parameter of startx:

$ startx "/usr/bin/application --key value"

Note that the full path is required. You can also specify custom options for the #xserverrc script by appending them after the double dash -- sign:

$ startx /usr/bin/enlightenment -- -br +bs -dpi 96

Autostart X at login

Make sure that startx is properly configured.

Place the following in your login shell initialization file (e.g. ~/.bash_profile for Bash or ~/.zprofile for Zsh):

if [ -z "$DISPLAY" ] && [ "$XDG_VTNR" = 1 ]; then
  exec startx
fi

You can replace the -eq comparison with one like -le 3 (for vt1 to vt3) if you want to use graphical logins on more than one virtual terminal.

Alternative conditions to detect the virtual terminal include "$(tty)" = "/dev/tty1", which does not allow comparison with -le, and "$(fgconsole 2>/dev/null || echo -1)" -eq 1, which does not work in serial consoles.

The exec command ensures that the user is logged out when the X server exits, crashes or is killed by an attacker. If you want to take the risk and remain logged in when the X session ends, remove exec.

Tip: This method can be combined with automatic login to virtual console.

Switching between desktop environments/window managers

If you are frequently switching between different desktop environments or window managers, it is convenient to either use a display manager or expand ~/.xinitrc to make the switching possible.

The following example shows how to start a particular desktop environment or window manager with an argument:

~/.xinitrc

...

# Here Xfce is kept as default
session=${1:-xfce}

case $session in
    i3|i3wm           ) exec i3;;
    kde               ) exec startplasma-x11;;
    xfce|xfce4        ) exec startxfce4;;
    # No known session, try to run it as command
    *                 ) exec $1;;
esac

To pass the argument session:

$ xinit session

or

$ startx ~/.xinitrc session

Starting applications without a window manager

It is possible to start only specific applications without a window manager, although most likely this is only useful with a single application shown in full-screen mode. For example:

~/.xinitrc

...

exec chromium

Alternatively the binary can be called directly from the command prompt as described in #Override xinitrc.

With this method you need to set each application's window geometry through its own configuration files (if possible at all).

Tip: This can be useful to launch graphical games, where excluding the overhead of a compositor can help improve the game's performance.

Output redirection using startx

See Xorg#Session log redirection for details.

Running in a virtual server

This article or section is a candidate for moving to Xorg.

Notes: Not related to xinit. (Discuss in Talk:Xinit)

Useful for running graphical applications:

Without showing their GUI.
On testcases.
Within a system that does not have xorg-server running.
While building in a clean chroot.

Install xorg-server-xvfb, then run xvfb-run command.