Departments & Programs


Using X Window

Last revision August 6, 2004

Table of Contents:
  1. What is a windowing system?
  2. The X Window system: definitions and concepts
  3. Server startup on Unix workstations
  4. Using an X terminal, PC or Macintosh as an X server
  5. XDMCP protocol for remote X servers
  6. Starting clients
  7. Authentication
  8. Window operations

X Window server startup on Unix workstations

On Unix workstations, the X server and client programs are often run on the same local machine. On most Unix workstations, the X server is always running and controlling the console display, including providing a fancy login dialog. On others, such as many Sun systems, you first log in on the console as a dumb terminal, and then start the X server by typing a command to start the X server. You need to consult the documentation for the workstation you are using to find out this command name. It could be simply X, or xinit, or openwin (on older Suns), or something else.

On pangea, and mpany Unix systems, a general overview of the X Window system can be found in the on-line manual entry for X, that is, by typing the command:

man X

On pangea, this is a very long manual entry with information about starting X sessions, standard X client programs, access control, fonts, colors, keyboard mappings, common program options, setting program preferences, example commands to start client programs, and more.

In any case, once logged in with X running, several default windows (client programs) are usually created for you, including a console terminal emulator window for system error messages (this is also the master shell for all your X clients) and a local xterm terminal emulator window for your normal command line login shell. The system manager can configure the default windows and may include a clock, load monitor, etc. Certain default resources such as fonts and colors are also set.

You can customize for your own account the list of default windows (clients) that start automatically with the X server. You do this with a initialization shell script in your home directory, usually named .xsession or .xinit. Consult the manual for the workstation you are using to find the exact name. This contains ordinary shell commands like the .login file that controls your login shell options, but applies only when you start the X server running on that particular workstation, or connect from an X terminal using XDMCP. Usually, if this script is present, it completely controls which X programs are started for your session. That is, the system defaults only apply if this script is absent.

You can also customize which software resources are made available automatically for your own account by the X server, such as background and foreground colors, scrolling behavior in terminal windows, etc., with a file in your home directory usually called .Xdefaults or .XResources. The exact name to use will be referenced in the .xsession or equivalent initialization script.

On modern Unix systems that use the Common Desktop Environment, the simplest way to customize your X sessions is to use the menus available once you are logged in. Your settings are automatically stored in special initialization files in your home directory.

Generally, the X environment on a Unix workstation is set up so that if you kill the console terminal emulator (e.g., type exit in that window), you will kill your entire X session (kill all running X clients that are using the display). Or, you can sometimes kill the whole session from the window manager process. For example, in the CDE interface used on most modern Unix systems, there is an Exit icon on the desktop; click on that to end your entire X session.

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