Linux system file permissions setting skills

The Windows system is similar to the Linux system. The properties of Windows system files and directories are read-only and hidden, and Linux is the same.
In Linux, every file has specific properties. It mainly includes two aspects: file type and file permission. There are five different types: normal files, catalog files, linked files, device files, and pipe files.
The so-called file permissions refer to access rights to files, including reading, writing, deleting, and executing files. Linux is a multi-user operating system that allows multiple users to log in and work at the same time. So Linux associates a file or directory with a user or group. The Access Control List (ACL) provides better access control for computers. It is used to restrict access to files, resources, or sockets for all users, including the root user. Here's how to set up a simple setup method.
Step 1 Check the system core
First check if the core of your Linux system has ACL support. Because Linux systems do not have the ability to support ACLs at the core of every version, the easiest way is to check if the current core of the system can support:
[root@mail /]# cat /boot/config-kernel- Version