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LightDM
LightDM is a cross-desktop display manager whose aim is to be the standard display manager for the X server.
The key features (as listed by upstream) include:
- A well-defined greeter API allowing multiple GUIs.
- Support for all display manager use cases, with plugins where appropriate.
- Low code complexity.
- Fast performance.
Installation
USE flags
USE flags for x11-misc/lightdm A lightweight display manager
+gnome
|
Add GNOME support |
+gtk
|
Pull in the gtk+ greeter |
+introspection
|
Add support for GObject based introspection |
audit
|
Enable support for Linux audit subsystem using sys-process/audit |
elogind
|
Enable session tracking via sys-auth/elogind |
non-root
|
Use non-root user by default |
qt5
|
Add support for the Qt 5 application and UI framework |
systemd
|
Enable use of systemd-specific libraries and features like socket activation or session tracking |
vala
|
Enable bindings for dev-lang/vala |
Emerge
Install lightdm:
root #
emerge --ask x11-misc/lightdm
Configuration
The (global) configuration file for LightDM can be found at:
- /etc/lightdm/lightdm.conf
GTK+
The GTK+ greeter configuration can be modified by manually editing the following file:
/etc/lightdm/lightdm-gtk-greeter.conf
RazorQt
The RazorQt greeter currently does not offer any configuration options.
Boot service
OpenRC
Set LightDM as the default display manager:
/etc/conf.d/xdm
DISPLAYMANAGER="lightdm"
To start LightDM on boot, add dbus and xdm to the default runlevel. dbus is necessary because LightDM depends on it to pass messages:
root #
rc-update add dbus default
root #
rc-update add xdm default
To start LightDM now:
root #
/etc/init.d/dbus start
root #
/etc/init.d/xdm start
systemd
To start LightDM on boot:
root #
systemctl enable lightdm
To start LightDM now:
root #
systemctl start lightdm
Command-line tool
LightDM includes a command-line tool, dm-tool, which can be used to switch user sessions, lock the current seat, etc. To see a list of available commands, use the --help
option:
user $
dm-tool --help
For example, to lock the current seat:
user $
dm-tool lock
Tips
Running commands at log-in
A user can run some programs automatically when logging in using LightDM by adding commands in ~/.xprofile, which will be sourced by LightDM. For example:
~/.xprofile
# Starting redshift, setting the dpi with xrandr and set the brightness to 50% with xbacklight xrandr --dpi 192 & redshift-gtk & xbacklight -set 50 &
Troubleshooting
Cursor themes not working
As of March 28, 2015, the stable versions of lightdm (lightdm-1.10.3) and lightdm-gtk-greeter (lightdm-gtk-greeter-1.7.0) have a bug that affects some DEs such as XFCE with setting the mouse cursor. Applications will apply the new mouse theme, but the root window where the window manager draws on does not. To get around this, simply unmask the latest versions (lightdm-1.13.2 and lightdm-gtk-greeter-2.0.0 at the time of writing) and the cursors will be set correctly.
More information can be found in Ubuntu's bug #1024482.
See also
- SDDM — a modern display manager that supports both the X11 server and the Wayland protocol.
- XDM —