CISE Help & Resources

Using XWindows at CISE

A default X setup has been installed for many reasons; partly to help us with administration of the system and partly to help you maintain your customizations across subtle system changes. The system is structured to allow for the three (3) main types of customizations:

In the absence of any customizations, the setup is designed to provide a basic but functional environment for CISE students and faculty.

For more information on the setup, refer to the following:

NEW X Setup:

Information on the new WindowMaker setup can be found here:

Information on the new KDE setup can be found here:

Old X Setup:

Common Problems

When trying to run an X application, you get the message "Error: Can't open display".
See the following question.
When trying to run an X application, it seems to be running, but nothing displays on the screen.
When you want to display an X application on your terminal, usually it is simply a matter of running it, but occasionally your application does not show up on your terminal. If you get a message Error: Can't open display, it means that your shell session is not authorized to connect to your display. Sometimes the program seems to run, but nothing is ever displayed on your terminal. In this case, it may mean that your shell session thinks it should be displaying somewhere other than your terminal.

Both of these occur frequently if you "leave" your normal CISE environment. This happens when you telnet/ssh outside of CISE, or when you drastically change your environment (especially when you use the "su" command or similar command to become another user).

To get around this, open up a local xterm and run the command: 
    xauth list | grep myhost
where myhost is the name of the host you want to use. For example, if you are on the machine "rain" and want to use it's display, type: 
    xauth list | grep rain
This will give you a line similar to the following: 
    rain.cise.ufl.edu:0  MIT-MAGIC-COOKIE-1 6ea722...
In the shell where you want to run the X program, set the DISPLAY environment variable to be this display. In csh or tcsh, type: 
    setenv DISPLAY rain.cise.ufl.edu:0
In a bourne style shell (zsh, ksh, bash, sh) type: 
    DISPLAY=rain.cise.ufl.edu:0
    export DISPLAY
Then you need to authorize this shell to use that display. Type the command: 
    xauth add rain.cise.ufl.edu:0 MIT-MAGIC-COOKIE-1 6ea722...
(all on one line). The easiest way to do this is to use the mouse to cut the entire line from the "xauth list" command and paste it after "xauth add".

You can now run X applications and display them on your local terminal.

Running X at Home on Windows

Caveat: While it is possible to run X Windows applications from home, it may not be usable with a very slow (i.e. modem) connection. In short, unless you have a Cable, or DSL connection (or faster) this is not for you.

If you are connecting from a Windows machine from home, and you want to run X apps remotely, you need the following:

Here is a tutorial that explains how to do it using X-Win32 and Putty, that seems to be the most popular combination.

About CISE

Academics

People

Research

News

Help & Resources

Info for Students

Info for Faculty & Staff

Industrial Advisory Board