Book Image

Essential Linux Commands

By : Paul Olushile
Book Image

Essential Linux Commands

By: Paul Olushile

Overview of this book

The role of a system administrator is ever-evolving, with the Linux command line at its core. This makes Linux command-line mastery an essential skill to demonstrate your ability to efficiently manage and maintain systems efficiently. Essential Linux Commands addresses a diverse range of topics, including package management, file manipulation, networking strategies, system monitoring, and diagnostic tools. Each command is intricately explained to eliminate any ambiguity, ensuring ease of implementation in real-world scenarios. This book explains how to use SELinux to maintain security, run Linux machines on AWS Cloud, and transfer and download files to remote systems. With the help of practical examples and use cases, you’ll not only gain a thorough understanding of a command’s syntax but also grasp its functional breadth and limitations. The book also explores commands frequently used by system administrators to check network card statistics and firewall rules. Whether you’re a beginner or an experienced administrator, this book is an invaluable resource, filling in the gaps in your skill set and helping you improve your skills and expertise in Linux administration.
Table of Contents (20 chapters)
1
Part 1:Server Installations and Management Commands
5
Part 2:Frequently Used Commands – Part 1
9
Part 3:Frequently Used Commands – Part 2
15
Part 4:Linux Security and the Cloud

The last command

The last command is a versatile and powerful tool used by Linux system administrators to view a history of user login activity on the system. It displays a list of previous login sessions, including the date, time, duration, and remote host from which the login occurred. This information is essential for monitoring user access to the system, identifying potential security breaches, and investigating unauthorized access attempts. The last command allows administrators to track user activities, detect unusual login patterns, and ensure the security and integrity of the system. Moreover, it facilitates auditing and compliance efforts by providing a comprehensive log of user login events, making it a crucial component of the system administrator’s toolkit.

The following example shows the last logged-in users and system shutdown/reboot times:

Figure 9.20 – Viewing last logged-in users and system shutdown/reboot times

Figure 9.20 – Viewing last logged-in users and system shutdown/reboot times