LightDM

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LightDM è un cross-desktop display manager whose il cui scopo è quello di essere il display manager standard per il server X.

Le caratteristiche principali (come indicato dagli sviluppatori) includono:

• Un ben definito greeter API consente ambienti grafici GUIs multipli
• Supporto per tutti i display manager utilizzati, con i plugins se necessari
• Bassa complessità del codice
• Performance veloci

Installazione

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

Data provided by the Gentoo Package Database · Last update: 2025-01-26 09:22 More information about USE flags

Emerge

Installare lightdm:

root #emerge --ask x11-misc/lightdm

Configurazione

La configurazione (globale) per LightDM può essere trovata su:

GTK+

The GTK greeter configuration can be modified by manually editing the following file:

/etc/lightdm/lightdm-gtk-greeter.conf

RazorQt

Il greeter RazorQt al momento non offre opzioni di configurazione.

Servizio di avvio

OpenRC

With display-manager

root #emerge --ask gui-libs/display-manager-init

Set LightDM as the default display manager:

FILE /etc/conf.d/display-manager

DISPLAYMANAGER="lightdm"

To start LightDM on boot, add dbus and display-manager 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 display-manager default

To start LightDM now:

root #rc-service dbus start

root #rc-service display-manager start

With the deprecated xdm init script

Impostare LightDM come display manager principale:

FILE /etc/conf.d/xdm

DISPLAYMANAGER="lightdm"

Per avviare LightDM all'avvio, aggiungere dbus e xdm sul default runlevel (runlevel predefinito):

root #rc-update add dbus default

root #rc-update add xdm default

Per avviare subito LightDM:

root #/etc/init.d/dbus start

root #/etc/init.d/xdm start

systemd

Per avviare LightDM all'avvio:

root #systemctl enable lightdm

Per avviare subito LightDM:

root #systemctl start lightdm

Strumento da riga di comando

LightDM include uno strumento per la linea di comando, dm-tool, che può essere utilizzato per spostarsi tra le sessioni utente, bloccare la sessione corrente, ecc... Per vedere una lista dei comandi disponibili, utilizzare l'opzione --help:

user $dm-tool --help

Per esempio, per bloccare la sessione corrente:

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:

FILE ~/.xprofile

# Starting redshift, setting the dpi with xrandr and set the brightness to 50% with xbacklight
xrandr --dpi 192 &
redshift-gtk &
xbacklight -set 50 &

Unlock GNOME Keyring

To unlock your GNOME Keyring (gnome-base/gnome-keyring) automatically on login, edit /etc/pam.d/lightdm to look as follows. Note: Lines ending with the comment #keyring should be added.

FILE /etc/pam.d/lightdm

auth     substack        system-local-login
auth     optional        pam_gnome_keyring.so #keyring
account  substack        system-local-login
password substack        system-local-login
session  substack        system-local-login
session  optional        pam_gnome_keyring.so auto_start #keyring

Locking the screen with elogind after suspend or sleep

For security, it is good practice to lock the screen after elogind triggers suspend or sleep. This can be done easily by doing the following:

Install light-locker:

root #emerge --ask x11-misc/light-locker

Start light-locker after the X server has started by putting light-locker & into either an ~/.xprofile or ~/.xinitrc file.

FILE ~/.xprofile

# Starting light-lock with X session
light-locker &

Create a lock.sh file under /lib64/elogind/system-sleep/ (be sure to add execute permissions to the file):

root #chmod +x /lib64/elogind/system-sleep/lock.sh

Risoluzione dei problemi

LightDM crashes upon first login if hostname changes during login

In some cases LightDM may crash when trying to log in for the first time if the hostname changes in the time between the boot and login (launchpad bug #1677058).

This may be encountered if net-misc/networkmanager is using the default settings to obtain the hostname from DHCP server and the hostname differs from the default one set on boot.

To disable NetworkManager hostname setting behavior, set the following line in [main] section of /etc/NetworkManager/NetworkManager.conf:

FILE /etc/NetworkManager/NetworkManager.conf

[main]
...
hostname-mode=none
...

LightDM fails to launch with Nvidia GPU

Users with Nvidia GPUs may encounter failures when using LightDM (GitHub issue #263).

A workaround for this issue involves editing /etc/lightdm/lightdm.conf and adding the line logind-check-graphical=false within the [LightDM] section.

FILE /etc/lightdm/lightdm.conf

[LightDM]
...
logind-check-graphical=false
...

See also

• SDDM — a modern display manager that supports both the X server and the Wayland protocol.