How to use the command fg (with examples)

The fg command is used to bring suspended or running background jobs to the foreground. It helps in managing and interacting with background processes.

Use case 1: Bringing most recently suspended or running background job to foreground

Code:

fg

Motivation: This use case is useful when you have recently suspended a background job and want to bring it back to the foreground to continue its execution or to interact with it directly.

Explanation:

• There are no arguments required for this use case.
• The fg command without any argument brings the most recently suspended or running background job to the foreground.
• It resumes the job and redirects its output to the terminal where the command is executed.

Example Output:

[1]+  Stopped                 sleep 60

In this example, the previously suspended job with job ID 1 (which is a sleep command waiting for 60 seconds) is brought to the foreground.

Use case 2: Bringing a specific job to foreground

Code:

fg %job_id

Motivation: This use case is helpful when you have multiple background jobs running concurrently and you want to bring a specific job to the foreground for closer monitoring or interaction.

Explanation:

• In this use case, you need to provide the job ID as an argument represented by job_id.
• The fg %job_id command brings the specific background job identified by job_id to the foreground.
• It resumes the job and redirects its output to the terminal where the command is executed.

Example Output:

[2]+  Stopped                 sleep 120

Here, the background job with job ID 2 (another sleep command waiting for 120 seconds) is brought to the foreground.

Conclusion:

The fg command is a handy tool for managing and interacting with background processes. By using it, you can easily bring suspended or running background jobs to the foreground, allowing you to monitor and control those processes effectively.