Which of the following environment variables must be set in remote shell in order to launch the graphical interface?

A developer is trying to install an application remotely that requires a graphical interface for installation. The developer requested assistance to set up the necessary environment variables along with X11 forwarding in SSH.

Which of the following environment variables must be set in remote shell in order to launch the graphical interface?
A . $RHOST
B . SETENV
C . $SHELL
D . $DISPLAY

View Answer

Answer: D

Explanation:

The environment variable that must be set in remote shell in order to launch the graphical interface is

$DISPLAY. This variable tells X11 applications where to display their windows on screen. It usually has the form hostname:displaynumber.screennumber, where hostname is the name of the computer running the X server, displaynumber is a unique identifier for an X display on that computer, and screennumber is an optional identifier for a screen within an X display. For example, localhost:0.0 means display number 0 on the local host. If the hostname is omitted, it defaults to the local host.

The other options are not correct environment variables for launching the graphical interface. $RHOST is a variable that stores the name of the remote host, but it is not used by X11 applications. SETENV is a command that sets environment variables in some shells, but it is not an environment variable itself. $SHELL is a variable that stores the name of the current shell, but it is not related to X11 forwarding.

References: How to enable or disable X11 forwarding in an SSH server; How to Configure X11 Forwarding Using SSH In Linux