Linux login Command with Practical Examples

Introduction

In this lab, we will explore the Linux login command and its practical applications. The lab covers understanding the basic syntax and usage of the login command, logging in as a regular user, and logging in as the root user. This lab is designed to provide a comprehensive understanding of the login command, which is a crucial tool for system administrators and users to access their accounts and perform various tasks on a Linux system.

The lab starts by explaining the basic syntax of the login command and its various options. It then demonstrates how to log in as a regular user by simply typing login and entering the username and password when prompted. Finally, the lab covers the process of logging in as the root user, which requires additional privileges and should be used with caution.

Linux Commands Cheat Sheet

Skills Graph

Understanding the login Command

In this step, we will explore the login command in Linux, which is used to log in to the system. The login command is a crucial tool for system administrators and users to access their accounts and perform various tasks.

First, let's understand the basic syntax of the login command:

login [options] [username]

The login command can be used with various options, such as -p to preserve the environment, -h to specify the host, and -f to force a login without authentication.

To log in as a regular user, simply type login and enter your username and password when prompted:

$ login
Username: labex
Password:

Example output:

Last login: Thu Apr 13 10:30:00 UTC 2023 on pts/0
Welcome to Ubuntu 22.04.2 LTS (GNU/Linux 5.15.0-69-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

This system has been minimized by removing packages and services to reduce
security risks and improve performance. If you need to restore functionality
please use the 'sudo apt-get install -y ubuntu-standard' command.

The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

labex@ubuntu:~/project$

The output shows that the user labex has successfully logged in to the system.

Logging in as a Regular User

In this step, we will learn how to log in as a regular user on the Linux system.

As mentioned in the previous step, the login command is used to log in to the system. To log in as a regular user, simply type login and enter your username and password when prompted:

$ login
Username: labex
Password:

Example output:

Last login: Thu Apr 13 10:30:00 UTC 2023 on pts/0
Welcome to Ubuntu 22.04.2 LTS (GNU/Linux 5.15.0-69-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

This system has been minimized by removing packages and services to reduce
security risks and improve performance. If you need to restore functionality
please use the 'sudo apt-get install -y ubuntu-standard' command.

The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

labex@ubuntu:~/project$

The output shows that the user labex has successfully logged in to the system as a regular user.

Logging in as the Root User

In this step, we will learn how to log in as the root user on the Linux system. The root user is the superuser with the highest level of privileges and access to the system.

To log in as the root user, you can use the login command with the root username:

$ login root
Password:

Example output:

Welcome to Ubuntu 22.04.2 LTS (GNU/Linux 5.15.0-69-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

This system has been minimized by removing packages and services to reduce
security risks and improve performance. If you need to restore functionality
please use the 'sudo apt-get install -y ubuntu-standard' command.

The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

root@ubuntu:~/project## ```

The output shows that the user has successfully logged in as the root user. Note that the prompt has changed to `root@ubuntu:~/project#`, indicating the root user.

As a best practice, it is recommended to use the `sudo` command instead of logging in as the root user directly. This helps maintain better security and control over the system.

Summary

In this lab, we explored the Linux login command, which is used to log in to the system. We learned the basic syntax of the login command and how to log in as a regular user by simply typing login and entering the username and password when prompted. We also discussed logging in as the root user, which requires special privileges and should be done with caution. The lab provided practical examples and highlighted the importance of the login command for system administrators and users to access their accounts and perform various tasks.

Linux Commands Cheat Sheet