Provided by: gdm3_3.18.3-0ubuntu2.2_amd64 bug


       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.


           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 <>

       This manual page written by Steve Haslam <> for Debian GNU/Linux.
       Updated by Raphaeel Hertzog <>, Ryan Murray <>,
       Josselin Mouette <> and Vincent Lefevre <>.