𝐋𝐢𝐧𝐮𝐱 𝐅𝐢𝐥𝐞 𝐏𝐞𝐫𝐦𝐢𝐬𝐬𝐢𝐨𝐧𝐬: 𝐀𝐧 𝐄𝐬𝐬𝐞𝐧𝐭𝐢𝐚𝐥 𝐒𝐤𝐢𝐥𝐥 𝐟𝐨𝐫 𝐃𝐞𝐯𝐎𝐩𝐬 𝐚𝐧𝐝 𝐒𝐑𝐄 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐬

As DevOps and SRE engineers, you are responsible for managing and maintaining the infrastructure and systems that run on Linux. One of the key concepts that you need to understand and master is Linux file permissions.

What are Linux file permissions?

Linux file permissions are a set of rules that control who can access, modify, and execute files and directories on a Linux system. These permissions are set for each file and directory on the system and determine what users or groups can perform specific actions on those files and directories.

The three basic types of permissions that can be set for files and directories in Linux are:

Read (r): Allows users to view the contents of a file or directory Write (w): Allows users to modify or delete files or directories Execute (x): Allows users to run files or access directories

In addition to these basic permissions, three types of users can be granted permission to access files and directories:

Owner [U]: The user who created the file or directory Group [G]: A group of users who have been granted permission to access the file or directory Others [O]: Any user who is not the owner or a member of the group

Each of these users can be granted a different level of permission to access and modify files and directories.

How does Linux File Permissions Work?

Linux file permissions are represented by a series of numbers and symbols. The numbers represent the permission level for each of the three types of users (owner, group, and others), and the symbols indicate the type of permission that has been granted (read, write, or execute).

The permission levels are represented as follows:

4: Read permission 2: Write permission 1: Execute permission

The permission levels for each user type are added together to create a three-digit number that represents the permission level for that file or directory. For example, if the owner has read and write permission, the group has read permission, and others have no permission, the permission level would be represented as 640 (4+2 for the owner, 4 for the group, and 0 for others).

The symbols used to represent permissions are as follows:

'r': Read permission 'w': Write permission 'x': Execute permission '-': No permission

Why are Linux file permissions important for DevOps and SRE engineers?

Linux file permissions are crucial for DevOps and SRE engineers, as they ensure system security and data management. Proficiency in this area is essential for tasks involving scripting and automation, which require interacting with files and directories without compromising system security.