It is important for a Linux administrator to find out all the users in their current system so that they can adjust the rules and privileges for each one.

The cat command is pretty useful for reading, creating, and concatenating files. While the tac command also works similarly to the cat command, which outputs the last line first.

The compgen command is a very handy tool available in major Linux distributions that can help you find your system aliases, commands, directories, groups, jobs, users, etc.

Learn how to use the systemctl command, which helps you manage your systemd service in the modern Linux operating system.

Symbolic links, sometimes also referred to as "symlinks," are used to create file pointers pointing towards files and directories in the Linux system.

The systemctl mask and systemctl disable are both crucial commands for Linux administrators, and you must know their differences to decide which one to choose in certain situations.

AWK is a domain-specific programming language that can be used as a Linux command-line tool or within a shell script.

The sed command is a stream editor that helps you to search, find and replace, insert and delete strings inside the text file without opening.

In Linux, stdin, stdout, and stderr streams are already part of your Linux system and attached to your terminal device to inspect the data.

The “/dev/null” file is a special file that can be found in all Linux systems. They are also referred to as “null device files,” “void,” and sometimes “a black hole of Linux”.

The file command on Linux is used to determine the MIME encoding (e.g. ‘image/jpeg; charset=binary’) or file type (e.g. ‘ASCII text’) for the target file.

The echo command takes the text or file as an argument and prints the output on the screen. It is mostly used in shell scripts to instruct the user or give any piece of information.

This article will teach you everything you need to know about the ls command, with plenty of practical examples you won't find anywhere else.

The PWD (a.k.a. "present working directory") will print the path of the directory you are currently working in, starting from the root directory to the current directory.

In this article, you learn how to use the stat command to check the properties of a referenced file, including file system related information.

In this article, you will learn how to change referenced file or directory permissions using the chmod command in Linux (with practical examples).

The chown command is used to modify the user and group ownership of files and directories. It will be helpful to restrict the access permissions for files and directories to selective users and members of group.

The passwd command is used to modify the user’s password and its properties, like deleting the password, expiring the password, deactivating the account, and many more.

When you create a new user account and set a password for that account, the "password expires" status is set to never; however, you can later force them to change their password on their next login.

The chage command is identical to the passwd command used to change user account and password expiration information.

Linux administrators are allowed to create "normal user accounts" with a range from 1000 to 60000 uids, where uid 0 is reserved for "root users" and "system users" are allowed uids from 1 to 999.