Linux Review basics of account and security

Accounts and Groups

1. Create Accounts and Groups

Useradd Create an account

-C Set Account description information

-D Set Account home directory

-e Set Account expiration date

-G Set the basic group of Accounts

-G set up an additional group of accounts

-M does not create home directories and is typically used in conjunction with-s

-S Set the login shell default to bash

Useradd-s/sbin/nologin

-U Specify account UID

2.groupadd creating groups

-G Set ID number

3.id

Describe account and group information

Modify accounts and Groups

1.password

+ User Change Password

Change account authentication Information

-L lock account, only root is available for this option

-U Unlock Account

-D Quick Erase password

2.usermod

Modify account information

-D Modify Account home directory

-e Modify Account expiration date

-G Modify the base group to which the user belongs

-G Modify the additional group to which the user belongs

-S Modify account login Shell

-U Modify account UID

3. Delete accounts and groups

Userdel

Delete accounts and related files

-R All Delete home directory

Groupdel

Delete a group account

Account information saved in/etc/password

Account password information saved in/etc/shadow

Group account information is saved in/etc/group

Group account password information is saved in/etc/gshadow

File and Directory Permissions

1.R W x

Viewing permissions with Ls-l

---------

Owner Group Other accounts

2. Modifying document properties

chmod

Eg:chmod 777 File name

chmod u=,g=,o= file name

chmod u:,g:,o: File name

ACL access Rights control

1.setfacl

eg:setfacl-m u::---file name

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Linux Review basics of account and security