Linux Job Foregrounding

Introduction

In the untamed vastness of the Wild West, a travelling merchant sets out in search of new opportunities and territories. Known for his adaptability and resourcefulness, this merchant knows the power of managing multiple tasks at once, much like commanding a herd of wild stallions. But even the most skilled cowboy occasionally needs to lasso a stray stallion and bring it back into focus.

In the wild frontier of Linux, tasks are like free-roaming stallions, and our merchant must learn to tame these processes and bring them to the forefront when they need direct attention. Your job is to help this entrepreneurial cowboy master the art of foregrounding tasks, using the fg command to effectively manage his many undertakings. Saddle up and prepare to turn the chaos of multitasking into productivity.

Skills Graph

Setting Up and Initiating Background Tasks

In this step, you will be helping our merchant set up his shop by simulating tasks in the background and then bringing a specific task forward.

Let's begin by creating a simple script to mimic a long-running task.

First, navigate to the ~/project directory:

cd ~/project

Create the script file named long_running_task.sh with the following code:

echo '#!/bin/bash' > long_running_task.sh
echo 'echo "Starting a long task...";sleep 60;echo "Task completed.";' >> long_running_task.sh

Make the script executable with the following command:

chmod +x long_running_task.sh

Now, run the script in the background:

./long_running_task.sh &

We will have multiple tasks running. Start another instance of the script:

./long_running_task.sh &

To bring the most recent background task to the foreground, use the fg command:

fg

You should now see a message indicating that the most recent background task has been brought to the foreground. Wait for the message "Task completed." indicating that the job has finished.

Foregrounding a Specific Job

In this step, you will assist our merchant to identify and bring a particularly important task, identified by its job number, to the foreground for immediate attention.

Let's send a couple of new tasks to the background:

./long_running_task.sh &
./long_running_task.sh &

Check the list of jobs to identify their numbers using jobs:

jobs

You will see a list of tasks with their respective job numbers, [1], [2], and so on. To bring a specific job to the foreground, use fg %jobnumber, replacing jobnumber with the job number from the list.

If you want to bring the second task to the foreground, you would type:

fg %2

Wait for the message "Task completed." indicating that the job has finished.

Summary

In this lab, we dove into the bustling world of the Wild West, undertaking the role of a traveling merchant who must expertly manage his tasks like a cowboy tames wild horses. We learned how to simulate and control long-running tasks using background and foreground operations. By writing scripts, manipulating jobs, and wielding the fg command, we gained practical skills in managing Linux processes. Through these exercises, you've harnessed the power of job control, a skill that enhances multitasking and efficiency in a Linux environment.

This lab aimed to relay a fundamental aspect of Linux job management in a hands-on, interactive way, ideal for beginners to contextualize and understand the material. By participating in the completion of this lab, you should now be comfortable with controlling background tasks and expertly focusing on specific jobs as demanded by your current working scenario.