Your SSH connection dropped while a long compile was running inside GNU screen. After logging in again, `screen -ls` lists one session marked (Detached). Which command puts you back into it?
LPIC-1 Exam 101-500, objective 103. GNU and Unix commands easy
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Treat it as a good draft rather than as settled fact, and read the source below before you rely on it. It is not used in mock exams here — only questions a person has signed for are.
How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Correct screen -r
Correct. -r reattaches a detached session; with only one to choose from, no session name is needed.
Not correct screen -ls
Wrong. -ls only lists the sessions and their attached or detached state, which you have already done.
Not correct screen -S build
Wrong. -S names a session at creation time, so this starts a second, empty session rather than returning to the existing one.
Not correct screen -d
Wrong. -d detaches a session that is currently attached elsewhere, the opposite of what is wanted. It is useful combined as -dr.
Why
screen keeps its windows running in processes that survive the loss of the controlling terminal, so a dropped connection leaves the session detached rather than dead. `screen -ls` lists sessions, `screen -r [name]` reattaches a detached one, and `screen -dr [name]` first detaches a session still held by another terminal and then attaches it here. tmux offers the same pattern with `tmux ls`, `tmux attach` and `tmux attach -d`.
Where this comes from
- Cited
- manual page screen(1)
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 103 and space the ones you get wrong.
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