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.

The groups command is used to list all the groups to which the specified user belongs. This will make it easier for you to manage users and groups in your system.

The ID command is used to display the user UID, group GID, and groups to which the current user belongs to help you with user management.

The getent command is used to fetch entries from the administrative text files like passwd, group, hosts, services, etc., also known as databases.

The gpasswd command is used to administer “/etc/group” and “/etc/gshadow” file by allowing you to manage group members in your Linux system.

The usermod command is a user management tool to modify user account information like username, user ID, default shell, home directory, and many more.

The which command locates the executable command or file location in the user’s environmental path. It will give you the complete path an executable command or file is pointing towards in your file system.

The whatis command is used to fetch a one-line description of the specified command or tool from the manual pages in your Linux system.

The whereis command is used to find the paths of binary, source, and manual files for a specified command, similarly to the find command but consuming less memory.