"Linux learning is not difficult" user management (1): Linux User account classification

9.1 "Linux learning is not difficult" User Management ( 1 ): Linux User Account Classification

user accounts in Linux systems are sub-roles, and because of different roles, each user's permissions and the work tasks they can perform are different. In the actual management, the user's role is identified by the UID(user ID number), each user's uid is different. There are three categories of users in the Linux system, namely root , System and ordinary users.

1 . root user

in the Linux System,the root user UID is 0,the root user's permissions are the highest, the ordinary user can not perform the operation,the root user is able to complete, So it is also called super User. every file, directory, and process in a Linux system belongs to one user, without user's permission, other ordinary users are unable to operate, except for the root user. the privileges of the root user also show that the root user can read, modify, and delete files or directories beyond any user and group (within the normal license of the system), can control execution and termination of the executable, and can add to the hardware device, Create and remove operations, or modify the properties and permissions of files and directories to suit the needs of system administration.

2 . System Users

system users are also referred to as virtual users, pseudo-users, or fake users, who do not have a login the ability of Linux system, but it is an indispensable user of system operation, such as bin,daemon,adm,ftp, mail, etc. This type of user is owned by the system itself. The UID of the system user is 1~999.

3 . Normal User

ordinary users can log in to the system, Linux System on the normal operation, can operate their own directory content, its use of the system is restricted, such users are created by the system administrator, the UID is between 1000~60000 .

Note:

in different versions of Linux System , when creating system users and ordinary users UID The range is different.

This article extracts from "Linux learning is not difficult" textbook, which is one of the most practical, theoretical and practical Linux Introductory materials.

"Linux learning is not difficult" user management (1): Linux User account classification