D.1 Using rlogin to Run a Networked Application

To use the following procedure to run a remote application, you must meet these requirements:

• You must have access rights to the remote machine.

• Your home directory must be NFS-mountable on the remote machine.

• The application and appropriate libraries must be installed on the remote machine, or host.

Contact your system administrator if you do not understand these requirements.

The key to running a networked application on a remote machine is to make sure your environment variables are set correctly:

• The HOME environment variable in your shell on the remote machine must be set to your home directory.

• The DISPLAY environment variable in your shell on the remote machine must be set to your local screen.

• If the OpenWindows libraries have not been installed in the standard /usr/lib or /usr/local shared library directories, you must set the LD_LIBRARY_PATH environment variable to the appropriate directory (/usr/openwin/lib).

Below is an example of running a Command Tool on a remote machine using rlogin. In this example, the home directory is mounted on the remote machine on /home/mydirectory, and the OpenWindows software is located in /usr/openwin on the remote machine. Change the variables, mydirectory and mymachine as appropriate for your arrangement. Also, replace cmdtool, with the name of the application you want to run.

$ rlogin remotemachine
   .
   .
(The following commands are executed on the remote machine.)]
   .
   .
$ HOME=/home/mydirectory
$ DISPLAY=mymachine:0
$ LD_LIBRARY_PATH=/usr/openwin/lib
$ /usr/openwin/bin/cmdtool &

After you enter the last line, a Command Tool window appears on your screen. Even though you interact with this application just as you would with any other application on your screen, the Command Tool application itself is actually running on the remote machine.

Although there is no particular advantage to running a Command Tool in this way (it is already locally available on your machine and does not use a significant amount of your computing resources), this example shows how to run any remote application that may be available to you.