In a bash shell, type the complete command that sets and exports the environment variable X clients read to find their display, so that they connect to screen 0 of display 0 on the local machine.
LPIC-1 Exam 102-500, objective 106. User interfaces and desktops medium
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How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
Answer
Type the answer.
Accepted answers
export DISPLAY=:0.0export DISPLAY=:0export DISPLAY=':0.0'export DISPLAY=":0.0"export DISPLAY=':0'export DISPLAY=":0"
Case sensitive — Linux is, and grading LS as ls would teach a falsehood.
Why
DISPLAY tells an X client which X server to contact, in the form host:display.screen. An empty host means the local machine over a Unix domain socket, so :0.0 is display 0, screen 0, locally; :0 is the common shorthand because screen 0 is the default. A remote form looks like workstation.example.com:0.0, and `ssh -X` sets DISPLAY to a proxy value such as localhost:10.0 in the remote shell. The variable must be exported, not merely set, so that child processes inherit it.
Where this comes from
- Cited
- LPI exam objective 106.1
- What it says
- Awareness of the DISPLAY variable and how X clients locate an X server.
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 106 and space the ones you get wrong.
More questions on this objective
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- Type the command, with no arguments and no options, that prints whether host-based access control is currently enabled on your X server together with the list of hosts and users allowed to connect. machine-checked
- An X11-forwarded ssh session authorises the remote client to talk to your local X server without you ever running an xhost command. Which mechanism provides that authorisation? machine-checked
- A display manager is the program that presents the graphical login screen and starts the user's session after authentication. Which three of the following are display managers? (Choose three.) machine-checked
- A user types with one hand and cannot hold Ctrl or Shift down while pressing another key. Which accessibility feature lets a modifier key stay active after it is released, so the next key press is combined with it? machine-checked