🐧 Linux System User and Group Management This chapter mainly explains the methods of Linux user and group management, including account addition, modification, deletion, password management, group management, and related system file structures. This knowledge is fundamental for system maintenance, security control, and permission management. 🧭 1. Management of Linux System User Accounts Linux is … Read more
🧱 Detailed Explanation of Linux File Attributes 📘 Understanding file attributes and permissions is the first step in mastering Linux system administration. 👥 1. Linux is a Multi-User System Linux is a typical multi-user operating system. Different users have different system permissions. To ensure system security, Linux has strict rules regarding “who can access which … Read more
In-Depth Analysis of Linux File Permissions: From Basics to Special Permissions 1. Linux File Types: Understanding the “ID Card” of Files 2. Basic Permissions: The Mystery of rwx 3. Permission Management Commands 4. Special Permissions: SUID, SGID, Sticky Bit 5. umask: Default Permission Control 6. ACL: Fine-Grained Permission Control 7. Practical Case Analysis 8. Permission … Read more
1. Command Introduction and Principles 1.1 Introduction ls (list) is one of the most basic and commonly used commands in Linux systems, used to list directory contents. It is a core tool for file system navigation and management, frequently used by almost all Linux users in their daily work. 1.2 Working Principles Directory Entry Reading: … Read more
Notes on Learning Linux This book uses CentOS 7/8 as the practical environment, focusing on practical Linux skills, progressing from basic commands to service deployment, making it a high-quality guide for beginners to learn Linux. The following summarizes the core content by chapter, highlighting practical focuses and knowledge difficulties. Chapter 1: Overview of Linux System … Read more
Understanding your needs, Linux system security is an important assessment content in the Information Security Engineer examination. I have designed a 5-day Linux crash course closely aligned with the exam points, incorporating analyses of past exam questions to help you prepare efficiently. To prepare for the exam, knowledge related to Linux may appear in multiple-choice … Read more
You have gained basic access to the server, and now you need to create covert accounts, disguise identities, and form a privileged team! Are you ready to become a master of user management? 🎯 Act 1: Reconnaissance – Viewing User Intelligence cat /etc/passwd # View all user profiles cat /etc/group # View all organizational structures … Read more
81. Question:_____ command provides an overview of the current resource usage of the system, including CPU, RAM, and swap space. Option 1: top Option 2: ps Option 3: ls Option 4: sysstat Correct Answer: 1 Explanation: The top command provides an overview of the current resource usage of the system, including CPU, RAM, and swap … Read more
Have you ever encountered a situation where your server suddenly raises a disk alert, and <span>df -h</span> shows that the root partition is 98% full, but you have no idea which directory is consuming the space? After deleting hundreds of MB of log files, the space still hasn’t been freed… Don’t worry, what you need … Read more
Just took over a Linux server that suddenly reports “Service failed to start” and can’t find the critical logs after searching through the /var/log directory? Many new operations staff may fall into the “log confusion” dilemma. In fact, by mastering 3 core commands and remembering common log paths, you can locate the issue in just … Read more