To simplify the startup of X applications on UNIX/Linux hosts, define the following environment variables on your host:
If you would like to start X applications on a Sun host running OpenWindows, you may also need to specify the following environment variables on your host:
This section describes how to define the DISPLAY environment variable for your current login session on a UNIX/Linux host. Many X applications use this variable to determine the X server display they should display.
Note: |
The syntax you use to specify the DISPLAY environment variable depends on whether you are using the C shell (displays a percentage "%" prompt, by default) or the Bourne or Korn shell (displays a dollar sign "$" prompt, by default). |
The following table lists the commands you need to type at the command prompt for each shell to set the DISPLAY environment variable.
Shell |
Command |
Example |
---|---|---|
C (%) |
setenv DISPLAY displayspec |
setenv DISPLAY eodhost:2 |
Bourne/Korn ($) |
DISPLAY=displayspec export DISPLAY |
DISPLAY=eodhost:2 export DISPLAY |
Note: |
Do not specify the DISPLAY environment variable in your host login Xstart file since your displayspec is not necessarily the same in each session. |
PATH, OPENWINHOME, and LD_LIBRARY_PATH Environment Variables
This section describes how to specify the PATH, OPENWINHOME, and LD_LIBRARY_PATH environment variables on UNIX/Linux hosts.
Note: |
The OPENWINHOME and LD_LIBRARY_PATH environment variables are needed only for Sun OpenWindows hosts. |
Using these environment variables, you can add directories to your path specification. If you enter a command without specifying its full path, the shell searches each directory listed in the PATH, OPENWINHOME, or LD_LIBRARY_PATH environment variables for the application executable and executes the first one it finds. Consider specifying these environment variables in your host login Xstart file so they are set each time you log on to the host.
The following table lists the commands required by each shell to set the PATH environment variable, where path is a directory that you want to include on your host path. Separate multiple paths with colons (:).
Shell |
Command |
Example |
---|---|---|
C (%) |
setenv PATH path:path:path |
setenv PATH /usr/bin/X11:/usr/bin/jsmith |
Bourne/Korn ($) |
PATH=path:path:path export PATH |
PATH=/usr/bin/X11:/usr/bin/jsmith export PATH |
The following table lists the commands required by each shell to set the OPENWINHOME and LD_LIBRARY_PATH environment variable, where usr is the directory on the host where the X Window system files reside.
Shell |
Example |
---|---|
C(%) |
setenv OPENWINHOME /usr/openwin setenv LD_LIBRARY_PATH /usr/openwin/lib |
Bourne/Korn($) |
OPENWINHOME=/usr/openwin LD_LIBRARY_PATH=/usr/openwin/lib export OPENWINHOME LD_LIBRARY_PATH |
To determine which environment variables are defined and their values, type the following commands at the shell prompt:
Shell |
Commands |
---|---|
C(%) |
setenv printenv |
Bourne/Korn($) |
env export printenv |
To determine if a specific environment variable is defined and to determine its value, type the following command at the shell prompt;
where variablename is the name of the environment variable.
If the environment variable is not defined or is incorrectly defined, define it properly in your host login Xstart file.
To define the environment variable in your host startup login file:
Note: |
If the environment variable is not defined, specify the environment variable by typing the command at the end of the file. |
The next time you start a shell session, your environment variable will be set according to your host startup login file. To verify this, start a new login/shell session and use the necessary commands described to determine the current value of these environment variables.