Linux the next day

File permissions and user groups

Groupadd Group Name

Groupadd Policeman

View Groups

Vi/etc/group

Cat/etc/group

Create a user and specify which group to assign the user to

USERADD-G Group name User name

View all user information in Linux

vi/etc/passwd

cat/etc/passwd

-rw-r--r--

-representative file type

rw-represents the file's owner's permissions on the file

The permissions are divided into three types, R can be read with 4 means W writable 2 means x executable with 1 means

r--represents the permissions for the file in the same group.

The last r--represents the permissions of the other group's users on the file.

How to modify the access permissions of a file

chmod 777 User 7 is exactly r (4) +w (2) +x (1) =7

chmod 777 along

chmod 770 Along the result is: drwxrwx---

chmod 664 Aaa.java

Add user specifies which group to add, same as root admin permission can change a user's group

USERMOD-G Group name User name

usermod-d Directory name User name change the initial directory where the user is logged on

Linux the next day