X without Display Manager

From Gentoo Wiki
Jump to:navigation Jump to:search

Traditionally, the X11 session is started by a display manager. However, when running a single-user system, display managers are not strictly necessary. This article describes how to start an X11 session without a display manager.

Starting X11 from console

Using startx

See the Using startx section of the Xorg/Guide article.

Using a dedicated session runner

Some of the desktop environments provide their own replacements for startx. For example, Xfce4 provides startxfce4:

user $startxfce4 -- vt7

Starting X11 automatically

Starting X11 on console login

To avoid having to run startx after login, logging in to a specific vt may be configured to start X11 automatically. One of the ways to achieve this is to put code into the shell's login script (e.g. ~/.bash_profile):

The GPU could have not been yet initialized when startx is executed. An easy solution would be to add sleep 5; before startx.


FILE ~/.bash_profileX11 autostart with login on tty1
if shopt -q login_shell; then
    [[ -f ~/.bashrc ]] && source ~/.bashrc
    [[ -t 0 && $(tty) == /dev/tty1 && ! $DISPLAY ]] && exec startx
    exit 1 # Somehow this is a non-bash or non-login shell.


FILE ~/.bash_profileX11 autostart with login on vt8
if [[ ! ${DISPLAY} && ${XDG_VTNR} == 8 ]]; then
    exec startx

The XDG_VTNR variable specifies the VT number. To use another VT adjust the number accordingly.

The additional DISPLAY check is necessary because the snippet will be executed on both graphical and non-graphical logins. Since XDG_VTNR will be set to the same value in the shells started within the X11 session (e.g. terminals), it is necessary to prevent them from trying to start X11.

The exec command causes the login shell to be replaced by the X11 session. This means that the user won't be able to use the shell used to start X11 anymore, and whenever the X11 session terminates, user will be logged back out. To remain logged in into vt, remove the exec word.

The DISPLAY check is fairly fragile. Make sure it isn't influenced by side-effects from earlier in the login process.

Ensure the user has permission to execute the ~/.bash_profile script:

user $chmod u+x ~/.bash_profile

Multiple X sessions/Virtual consoles

An alternate method is to auto-login to a Window Manager (WM) or a Desktop Environment (DE) depending on the Virtual Console (VT) used to login. A fallback session can be easily achieved in this manner. Just grab the following file excerpts to get going:

First, set up the sessions or WM or DE to use depending on the VT:

# $Header: ~/.xinitrc, 2014/11/22 Exp $
case $(tty | cut -b9-) in
	(1) exec enlightenment_start;;
	(2) exec lxsession          ;;
	(3) exec openbox-session    ;;

And then set up the login shell accordingly:

# $Header: ~/.bash_login, 2014/11/30 Exp $
# Auto startx depending on the VT
if [[ -z "$DISPLAY" && $(id -u) -ge 1000 ]] ; then
    [[ "${TTY/tty}" != "$TTY" && "${TTY:8:1}" = "3" ]] &&
        startx 1>~/.log/xsession-errors 2>&1 &
    unset TTY

Or else, a zsh variant could be used instead.

# $Header: ~/.zlogin, 2014/11/30 Exp $
# Auto startx depending on the tty
if [[ -z $DISPLAY ]] && (( $EUID != 0 )) {
    [[ ${TTY/tty} != $TTY ]] && (( ${TTY:8:1} <= 3 )) &&
        startx 1>~/.log/xsession-errors 2>&1 &

The previous files can be used to login into an Enlightenment or LXDE session without needing any middle man or rather Display Manager (DM)! and Openbox session as a fallback session using VT 1, 2, and 3.

Adapt to preferred DE or WM.

X11 autologin with systemd

Method 1

In order to obtain complete X11 autologin, it is possible to use the getty/login autologin feature along with the aforementioned trick.

First, create a new service file like the following:

FILE /etc/systemd/system/x11.serviceAn example service file for X11 autologin

ExecStart=/sbin/mingetty --autologin username --noclear tty8 38400


username replaced by the user's username, and tty8 being the tty the X11-starting login to be performed on. It should be noted that this tty will be used for login and console output, and X11 can be started on any other tty.

This way can only be used for vt7+. Earlier vts are used by default getty generator and require a different kind of hackery.

Afterwards, add the previous snippet to bashrc (with the same vt specified), enable the service:

root #systemctl enable x11.service

In order to avoid relying on the DISPLAY+XDG_VTNR trick to determine whether to start X11, the two above approaches may be extended by using a dedicated environment variable to distinguish the specific shell where X11 is to be started.

First, create a dedicated login wrapper:

FILE /usr/local/sbin/x11loginX11 vt login wrapper
exec /bin/login "${@}" START_X11=1

This causes the user to be logged in with START_X11=1 environment variable set. Then, tell getty to use that file instead of the default /bin/login:

FILE /etc/systemd/system/x11.serviceX11 autologin service using login wrapper

ExecStart=/sbin/mingetty --autologin username --loginprog=/usr/local/sbin/x11login --noclear tty8 38400


Finally, modify ~/.bashrc (or equivalent) to use the variable rather than guessing:

FILE ~/.bashrcX11 autostart checking dedicated variable
if [[ ${START_X11} == 1 ]]; then
    unset START_X11
    exec startx

Remember to unset the variable before starting X11 -- otherwise all the X11 terminals would have it set and try to spawn another X11 session.

Method 2

An alternative method is to use su and xinit for direct login in X.

Service example:

FILE /etc/systemd/system/xinit-login.serviceAn example service file for X11 autologin using su and xinit

ExecStart=/bin/su username -l -c /usr/bin/xinit -- VT08


startx can be used rather than xinit.

In case X startup fails with the error Xorg.wrap: Only console users are allowed to run the X server then read man Xorg.wrap how to allow any user to do so.


Automatic user selection

On a 1-user system it's possible to avoid typing the username, so the login prompt will ask only for the password. E.g. adjust /etc/inittab so that the third terminal asks about the password only:

FILE /etc/inittabPreselect user in TERMINALS section
c3:2345:respawn:/sbin/agetty --noclear --skip-login --login-options=my_user 38400 tty3 linux

Of course, one can have various preselected users on different terminals, e.g. user_a on tty1 and user_b on tty2.

Custom text in console logon

It is possible to create a simple wrapper for /bin/login to show supplementary information on the console logon screen. E.g. on a 1-user system one may wish to see if there are any new emails without logging in. First, create a simple bash wrapper for /bin/login:

FILE /root/login.shWrapper for /bin/login

# Show sender and subject of all new emails:
egrep -r --max-count=2 '^(From|Subject|$):' ~email_user/.maildir/new

# Show user count, terminal, time, kernel version:
echo $(who -q) $(tty) $(date '+[%b-%-d %-H:%M]') $(uname -r)

# Continue with normal login:
exec /bin/login preselected_login_user

The last line calls the actual /bin/login which will do all the heavy lifting. Omit the user name in that line to be prompted for it. Passing a username results in being prompted about the password only.

Finally edit /etc/inittab to use login.sh wrapper, here on tty2:

FILE /etc/inittabUse login.sh wrapper
c2:2345:respawn:/sbin/agetty --noclear --skip-login --login-program=/root/login.sh 38400 tty2 linux