Linux Foundation Certified System Administrator Exam: List of Background Tasks | Exam LFCS

List of Background Tasks

Question

SIMULATION -

Which command displays a list of all background tasks running in the current shell? (Specify ONLY the command without any path or parameters.)

Explanations

jobs

The command that displays a list of all background tasks running in the current shell is jobs.

When a command is executed in the shell, it can either run in the foreground or in the background. Foreground processes take control of the shell, and you must wait for them to complete before you can enter another command. On the other hand, background processes run independently of the shell, allowing you to continue working in the terminal while they run.

To run a command in the background, you can append an ampersand (&) to the end of the command. For example, the command sleep 10 & will run the sleep command in the background for 10 seconds.

Once you have started a background process, you can use the jobs command to see a list of all the background tasks running in the current shell session. This command displays a list of all the running background jobs, along with their job numbers.

For example, if you had started a background process with the sleep 10 & command, you could use the jobs command to see the job status:

shell
$ sleep 10 & [1] 1234 $ jobs [1]+ Running sleep 10 &

In this example, the sleep 10 command is running as a background job with a job number of 1. The output of the jobs command shows that the job is still running.

Note that the jobs command only shows background tasks running in the current shell session. If you open a new shell session, any background tasks running in the previous session will not be displayed by the jobs command.