You press Ctrl+Z while a long-running command occupies the foreground of your bash shell. What happens?
LPIC-1 Exam 101-500, objective 103. GNU and Unix commands easy
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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.
The options
Not correct The job continues in the background immediately.
Wrong. Ctrl+Z only suspends. You must then run `bg` to let the stopped job continue in the background.
Not correct The job is terminated by SIGINT.
Wrong. SIGINT is what Ctrl+C sends, and it normally terminates the foreground job rather than suspending it.
Not correct The job keeps running but is detached from the terminal.
Wrong. Nothing is detached; the job is stopped and consumes no CPU. Detaching from the terminal is what nohup, disown or a screen/tmux session do.
Correct The job is stopped (suspended) and control returns to the shell prompt.
Correct. Ctrl+Z sends SIGTSTP, which suspends the job. It appears in `jobs` as Stopped and can be resumed with fg or bg.
Why
Ctrl+Z sends SIGTSTP and the job stops. `jobs` lists it, `bg %1` resumes it in the background, `fg %1` brings it back to the foreground. A stopped job is frozen — it makes no progress until it receives SIGCONT via bg or fg.
Where this comes from
- Cited
- LPI exam objective 103.5
- What it says
- Manage background and foreground jobs with jobs, bg and fg.
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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