gdm is the equivalent of xdm(1x) or wdm(1x), but uses the \s-1GNOME\s0
libraries to provide a \s-1GNOME\s0 look-and-feel. It provides the \s-1GNOME\s0
equivalent of a login: prompt.
gdm reads /etc/gdm/gdm.conf for its configuration. For each
local display, gdm starts an X server and runs gdmlogin(8x) on that
display. The main gdm process also listens for \s-1XDMCP\s0 requests from
remote displays. These requests can either be direct, causing gdmto start a gdmlogin(8x) on the remote display, or indirect, causing
a gdmchooser(8x) to be opened.
When managing a display, gdm attempts to execute
/etc/gdm/Init/display, or /etc/gdm/Init/Default if that does
not exist. When a user logs in, gdm first attempts
/etc/gdm/PreSession/display (or /etc/gdm/PreSession/Default),
and then one of the sessions in /etc/gdm/Sessions. When the session
has completed, gdm attempts to run
/etc/gdm/PostSession/Default. Of all these files, only the
/etc/gdm/Sessions one is required to exist.
gdm maintains information about the displays it is managing in
/var/lib/gdm. This includes xauth information, so this directory
is not readable to normal users.
gdm uses \s-1PAM\s0 to perform authentication using the config file
Martin Kasper Petersen <mkp@SunSITE.auc.dk>
This manual page written by Steve Haslam <email@example.com> for
Debian GNU/Linux. Updated by Rapha