Without display manager you need to log in into the console and then statrx.
Display Managers put them selfs in between those two steps. They are started by
adding display-manager to the default boot level: rc-update add display-manager default.
This reads the file/etc/conf.d/display-manager
that contains the name of the
login manager. After login startx starts what is stored in the XSESSION environmental variable or does what is inside the
file~/.xinitrc
of the user that has logged in.
Most desktop environments com with their own display manager that replaces xdm as gdm for gnome, kdm for kde and lxdm for LXDE.
startx test it, see log file for problems:
/var/log/Xorg.0.log
Ctrl + D exits
startx checks if in your home directory
~/.xinitrc
exist. If so, it starts what it will find
inside. Maybe you have done one of the following commands:
echo "exec startxfce4" > ~/.xinitrc
echo "exec startkde" > ~/.xinitrc
This command created the file~/.xinitrc
,
and executes kde. Otherwise it starts the session found in
/etc/X11/Sessions
where/etc/rc.conf
points to.
To start x automatically rc-update add display-manager default. This starts the Display manager as default xdm that allows
also to login graphically. If you use an other login manage set its name in/etc/conf.d/display-manager
For Gentoo display-manager-init replaced xdm and had its config file /etc/conf.d/xdm
and requires rc-update add xdm
X is a display server, the program name is Xserver. Check man Xserver
The script startx is a script in and calls xinit that calls Xserver.
See man startx to see for example how options are passed.
Slim is a lightweight login manager. See https://sourceforge.net/projects/slim.berlios/. Slim has also a log file
/var/log/slim.log
.
Slim will start per default what is set by the environmental variable XSESSION that is initialized
via/etc/rc.conf
.
Alternatively the environmental variable can be set via/etc/end.d
add XSESSION="Xfce4" to/etc/env.d/90xsession
env-update && source /etc/profile
To have a setting per user ~/.xinitrc
has to be started. Put the following
login_cmd exec /bin/sh - ~/.xinitrc %session
command in/etc/slim.conf
Unfortunately slim does not have an autologin with timeout and it maps the numeric key to the laptop keypad (Fn)
Lightdm is an other display manager with its config file /etc/lightdm/lightdm.conf
Lightdm is not as light as it seems to be, it is full featured but needs no special configuration on config file levels. It can login a user automatically with a time out for intervention.
sddm is recommended to be used with LXQT. https://wiki.gentoo.org/wiki/SDDM
However it has issues with keyboard localization layout.