Using jobs Command

Introduction

The jobs command in Unix-like operating systems is used to display the status of jobs managed by the current shell session. Jobs are processes that are started by the shell. Understanding how to use the jobs command effectively can help you manage background and foreground processes efficiently.

Basic Usage

To see the list of current jobs, simply run the jobs command without any arguments:

In this example, the output shows two jobs. The first job is a background job running the sleep 100 command, and the second job is a stopped nano editor.

Job States

Jobs can be in different states:

• Running: The job is currently executing.
• Stopped: The job has been paused by a signal.
• Terminated: The job has completed execution.

Controlling Jobs

Bringing a Job to the Foreground

To bring a background job to the foreground, use the fg command followed by the job number:

This command brings job number 1 to the foreground.

Sending a Job to the Background

To send a foreground job to the background, use the bg command followed by the job number:

This command resumes job number 2 in the background.

Managing Job Control

Stopping a Job

To stop a running job, use the Ctrl+Z keyboard shortcut. This will suspend the job and return you to the shell prompt. For example:

Resuming a Stopped Job

To resume a stopped job in the foreground, use the fg command:

To resume a stopped job in the background, use the bg command:

Practical Examples

Example 1: Running Multiple Background Jobs

Here’s how you can start multiple background jobs and list them using the jobs command:

Example 2: Managing Job States

Start a job, stop it, and then resume it:

Conclusion

The jobs command is a powerful tool for managing processes in a Unix-like operating system. By understanding how to list, stop, and resume jobs, you can effectively control the execution of multiple processes within your shell session. Use this knowledge to manage your command-line tasks more efficiently.