LPI Linux Certification in a Nutshell, 2nd Edition

Objective 2: Set Up a Display Manager

The display manager is the tool to manage X sessions on physical displays both locally and across the network. Part of its job is to handle user authentication through a graphical login screen, which replaces the familiar text-mode login.

Configuring xdm

xdm is distributed as part of XFree86 and is configured by a series of files located in /etc/X11/xdm. These files include:

Xaccess

This file controls inbound requests from remote hosts.

Xresources

This file is similar to .Xresources, discussed earlier. It holds configuration information for some xdm resources, including the graphical login screen. This file can be edited to modify the appearance of the xdm login screen.

Xservers

This file associates the X display names (:0, :1, ...) with either the local X server software or a foreign display such as an X terminal.

Xsession

This file contains the script xdm launches after a successful login. It usually looks for .xsession in the user's home directory and executes the commands found there. If such a file doesn't exist, Xsession starts a default window manager (or environment) and applications.

Xsetup_0

This file is a script started before the graphical login screen. It often includes commands to set colors, display graphics, or run other programs. This script is executed as root.

xdm-config

This file associates xdm configuration resources with the other files in this list. It usually isn't necessary to make changes in this file unless an expert ...