When you execute a unix shell-script or command that takes a long time, you can run it as a background job.
In this article, let us review how to execute a job in the background, bring a job to the foreground, view all background jobs, and kill a background job.
Executing a background job
Appending an ampersand ( & ) to the command runs the job in the background.
For example, when you execute a find command that might take a lot time to execute, you can put it in the background as shown below.
- yum update &
Sending the current foreground job to the background using CTRL-Z and bg command
You can send an already running foreground job to background as explained below:
- Press ‘CTRL+Z’ which will suspend the current foreground job.
- Execute bg to make that command to execute in background.
View all the background jobs using jobs command
You can list out the background jobs with the command jobs
Taking a job from the background to the foreground using fg command
You can bring a background job to the foreground using fg command. When executed without arguments, it will take the most recent background job to the foreground
If you have multiple background ground jobs, and would want to bring a certain job to the foreground, execute jobs command which will show the job id and command.
In the following example, fg %1 will bring the job#1 (i.e download-file.sh) to the foreground.
Kill a specific background job using kill %
If you want to kill a specific background job use, kill %job-number. For example, to kill the job 2 use
# kill #1