1, for a file, user classification
Master, family, strangers.
UID and GID
UID indicates ID number of user ID
GID represents the ID account number of Group ID user groups
2. User classification in the system
1) Root Super Admin Emperor 0
2) Puppet user virtual user 1-499
is to satisfy each running process of Linux to have a corresponding user and user group, unable to log on to the system ******
3) Ordinary users of the people of the cloth
3. User-related files
/ETC/PASSWD Information for users
/etc/shadow user's password and password information
/etc/group User Group Information
/etc/gshadow user group password and password information
4. User information contained in/ETC/PASSWD
Root:x: 0:0: Root:/root:/bin/bash
OLDBOY:X: 500:500::/home/oldboy:/bin/bash
ALEX:X: 501:501::/home/alex:/bin/bash
User name: Store password location: uid:gid: User description: User's home directory: User-used Shell (command interpreter)
/bin/bash # # #默认的命令解释器
/sbin/nologin # # #这个用成为了虚拟用户 (puppet user)
Deleting the x stored in the password is equivalent to deleting the password.
Exercises:
1. What are the user-related documents?
2. What are the categories of users?
Linux Basic Learning -9.3-users and user groups