[Linux] Bash bg Usage: Resume suspended jobs in the background

Overview

The bg command in Bash is used to resume a suspended job and run it in the background. This allows users to continue working in the terminal while the job executes without occupying the foreground.

Usage

The basic syntax of the bg command is as follows:

bg [job_spec]

Where job_spec refers to the job number or job ID of the suspended job you want to resume.

Common Options

• job_spec: Specifies which job to resume. This can be a job number (e.g., %1) or a job ID (e.g., 1234).

Common Examples

1. Resume the most recent suspended job: If you have suspended a job (e.g., by pressing Ctrl+Z), you can resume it in the background with:

   bg
   

2. Resume a specific job by job number: If you have multiple jobs suspended, you can specify which one to resume:

   bg %1
   

   This resumes the job with job number 1.

3. Resume a specific job by job ID: If you know the job ID, you can also use it to resume the job:

   bg 1234
   

   This resumes the job with the ID 1234.

4. Check the status of jobs before resuming: To see a list of suspended jobs, use the jobs command:

   jobs
   

   This will display all jobs along with their job numbers, which you can use with bg.

Tips

• Always check the status of your jobs with the jobs command before using bg to ensure you are resuming the correct job.
• If you want to bring a job back to the foreground instead of the background, use the fg command.
• Remember that background jobs may still produce output to the terminal, so consider redirecting their output if needed.