Provided by: gdm3_3.18.2-1ubuntu2_i386 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


           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 <>.