Provided by: gdm3_3.28.0-0ubuntu1_amd64
gdm3 - GNOME Display Manager
gdm3 is the equivalent of xdm(1x) or wdm(1x), but uses the GNOME libraries to provide a GNOME look-and-feel. It provides the GNOME equivalent of a "login:" prompt. gdm3 reads /etc/gdm3/custom.conf for its configuration. For each local display, gdm starts an X server and runs a minimal GNOME session including a graphical greeter. If configured so, the main gdm process also listens for XDMCP requests from remote displays. These requests can either be direct, causing gdm3 to start a session on the remote display, or indirect, causing a chooser to be opened. When managing a display, gdm3 attempts to execute /etc/gdm3/Init/display, or /etc/gdm3/Init/Default if that does not exist. When a user logs in, gdm3 first attempts /etc/gdm3/PreSession/display (or /etc/gdm3/PreSession/Default), and then one of the sessions defined in /usr/share/xsessions. When the session has completed, gdm attempts to run /etc/gdm3/PostSession/display, or /etc/gdm3/PostSession/Default. gdm3 maintains information about the displays it is managing in /var/lib/gdm3. This includes xauth information, so this directory is not readable to normal users. gdm3 uses PAM to perform authentication using the config file /etc/pam.d/gdm3.
XAUTHORITY Upon session startup, GDM sets the XAUTHORITY environment variable to a session- specific file in /var/run/gdm3. Applications and scripts that assume this file is set to ~/.Xauthority will not work. To access the display you need both DISPLAY and XAUTHORITY variables.
Martin Kasper Petersen <mkp@SunSITE.auc.dk> This manual page written by Steve Haslam <email@example.com> for Debian GNU/Linux. Updated by Raphaeel Hertzog <firstname.lastname@example.org>, Ryan Murray <email@example.com>, Josselin Mouette <firstname.lastname@example.org> and Vincent Lefevre <email@example.com>.