Basic Linux Learning (7)

Seventh chapter-User and user group Management one. User Profile 1. User Information file/etc/passwd:

(1) User Management Introduction: So the more server security requirements of the server, the more need to establish a reasonable level of user rights and server operating norms.

In Linux, user information is viewed and modified primarily through user profiles. (2)/etc/passwd:

(3) Initial and additional groups:

(4) What the shell is:

2. Shadow file/etc/shadow:

(1) Shadow file/etc/shadow:

(2) time stamp conversion:

3. Group information file/etc/group and group password file/etc/gshadow:

(1) Group information file/etc/group:

(2) Group password file/etc/gshadow:

Two. User Management related files

(1) User's home directory: normal User:/home/user name/, owner and owning group are this user, permission is 700;

Superuser:/root/, owner and owning group are root users, permissions are 550

(2) User's email:/var/spool/mail/User name/

(3) User Template directory:/etc/skel/

Three. User management commands 1. User add Command useradd:

(1) Useradd command format:

(2) Add Default User:

(3) Specify options to add Users:

(4) User default value file:

2. Modify User password passwd:

(1) passwd command format:

(2) Check the status of the password:

(3) lock user and unlock User:

(4) Use a string as the user's password:

3. Modify user information Usermod Modify user password status Chage

(1) Modify user information Usermod:

(2) Modify user password status chage:

4. Delete user Userdel, user switch command su:

(1) Delete user userdel:

(2) Manually delete the user:

(3) View User id:

(4) Switch user identity su:

Four. User group management Commands 1. Add a user group:

2. Modify user groups:

3. Delete user groups: (no initial user allowed, allow additional users to exist)

4. Add the user to the group or remove it from the group:

Basic Linux Learning (7)