Final answer:
To set the display environment variable in Linux, use the 'export' command followed by 'DISPLAY=:0', replacing ':0' with your display configuration. To see the current DISPLAY value, use 'echo $DISPLAY'. To make changes permanent, add them to your '~/.bashrc' or '~/.profile' file.
Step-by-step explanation:
To set the display environment variable in Linux, it's crucial to understand the role of environment variables in the operating system. They are used to define the behavior of processes in a session. The DISPLAY environment variable instructs an X client on which X server it is supposed to connect to by default.
Firstly, to see the current value of the DISPLAY variable, you can use the following command in the terminal:
echo $DISPLAY
This command will return the current value, such as ':0'. This value indicates the first display screen on the machine.
To set or change the DISPLAY variable, you can use the export command as follows:
export DISPLAY=:0
You would replace ':0' with the appropriate display number or network information depending on your configuration.
For example, if you're working on a remote server via SSH and need to forward graphical applications to your local X server, you could use:
export DISPLAY=localhost:10.0
This would tell the applications to use the local machine's display.
If the changes to the DISPLAY variable are meant to be permanent, you need to add the export command to the end of your ~/.bashrc or ~/.profile file, so it gets executed every time you open a terminal session.
Remember that messing with environment variables can affect your system's behavior; always be sure of the changes you make.