Linux atd Command with Practical Examples

Introduction

In this lab, you will learn how to use the Linux atd command to schedule one-time tasks and monitor and control those scheduled tasks. You will start by understanding the atd command and its usage, then move on to scheduling a one-time task using the atd command. Finally, you will explore how to monitor and control the scheduled tasks, including viewing the list of scheduled tasks, removing tasks, and viewing the details of a scheduled task.

The lab covers the essential aspects of process management in Linux, providing practical examples and hands-on experience with the atd command. By the end of this lab, you will have a solid understanding of how to effectively manage scheduled tasks on your Linux system.

Linux Commands Cheat Sheet

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL linux(("`Linux`")) -.-> linux/BasicSystemCommandsGroup(["`Basic System Commands`"]) linux(("`Linux`")) -.-> linux/TextProcessingGroup(["`Text Processing`"]) linux(("`Linux`")) -.-> linux/FileandDirectoryManagementGroup(["`File and Directory Management`"]) linux(("`Linux`")) -.-> linux/BasicFileOperationsGroup(["`Basic File Operations`"]) linux(("`Linux`")) -.-> linux/SystemInformationandMonitoringGroup(["`System Information and Monitoring`"]) linux/BasicSystemCommandsGroup -.-> linux/echo("`Text Display`") linux/TextProcessingGroup -.-> linux/grep("`Pattern Searching`") linux/FileandDirectoryManagementGroup -.-> linux/cd("`Directory Changing`") linux/FileandDirectoryManagementGroup -.-> linux/mkdir("`Directory Creating`") linux/BasicFileOperationsGroup -.-> linux/ls("`Content Listing`") linux/SystemInformationandMonitoringGroup -.-> linux/ps("`Process Displaying`") subgraph Lab Skills linux/echo -.-> lab-422558{{"`Linux atd Command with Practical Examples`"}} linux/grep -.-> lab-422558{{"`Linux atd Command with Practical Examples`"}} linux/cd -.-> lab-422558{{"`Linux atd Command with Practical Examples`"}} linux/mkdir -.-> lab-422558{{"`Linux atd Command with Practical Examples`"}} linux/ls -.-> lab-422558{{"`Linux atd Command with Practical Examples`"}} linux/ps -.-> lab-422558{{"`Linux atd Command with Practical Examples`"}} end

Monitoring and Controlling Scheduled Tasks

In this step, we will learn how to monitor and control the scheduled tasks using the at command.

To view the list of scheduled tasks, use the atq (at queue) command:

atq

This will display the job ID, date and time, and the user who scheduled the task.

Example output:

3       2023-04-14 12:40 a labex

If you want to remove a scheduled task, use the atrm (at remove) command followed by the job ID:

atrm 3

This will remove the task with the job ID 3 from the queue.

You can also use the at -c [job_id] command to view the details of a scheduled task, including the commands that will be executed:

at -c 3

Example output:

#!/bin/sh
## atrun uid=1000 gid=1000
## mail labex 0
echo "Hello, World!" > ~/project/output.txt

This shows the shell script that will be executed when the scheduled task runs.

Summary

In this lab, you learned how to monitor and control scheduled tasks using the at command. You can view the list of scheduled tasks with the atq command, remove a task with the atrm command, and view the details of a scheduled task with the at -c [job_id] command. This allows you to manage your scheduled tasks effectively and ensure they are executed as planned.