Linux Job Control: bg, fg & Ctrl+Z

Job Description

A job is a process that the shell manages. Each job is assigned a sequential job ID. Because a job is a process, each job has an associated PID. There are three types of job statuses:

1. Foreground: When you enter a command in a terminal window, the command occupies that terminal window until it completes. This is a foreground job.
2. Background: When you enter an ampersand (&) symbol at the end of a command line, the command runs without occupying the terminal window. The shell prompt is displayed immediately after you press Return. This is an example of a background job.
3. Stopped: If you press Control + Z for a foreground job, or enter the stop command for a background job, the job stops. This job is called a stopped job.

Job Control Commands

Job control commands enable you to place jobs in the foreground or background, and to start or stop jobs. The table describes the job control commands.