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This article mainly explains "the usage of the Linux basic command useradd". The content of the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "the usage of the Linux basic command useradd".

Useradd

To create a new system user, the useradd directive can only be run as an administrator, and the created users are in the "/ etc/passwd" file. When the-D parameter is not added, the useradd instruction uses the command line to specify the settings for the new account and uses the default values on the system. The new user account will generate some system files, user directory creation, copy starting files, etc., all of which can be specified by command line options. This version is available for RedHat Linux and allows each new user to create a separate group without adding the-n option.

The scope of this command: RedHat, RHEL, Ubuntu, CentOS, SUSE, openSUSE, Fedora.

1. Grammar

Useradd [- D] [options] [parameters]

Useradd [- c comment] [- d home_dir] [- e expire_date] [- f inactive_time] [- g initial_group] [- G group [,...]] [- m [- k skeleton_dir] |-M] [- s shell] [- u uid [- o]] [- n] [- r] login

Useradd-D [- g default_group] [- b default_home] [- f default_inactive] [- e default_expire_date] [- s default_shell]

2. List of options

Option

Description

-- help

Show help documentation

-- version

Show command version

Use the-D option

-b dir

Specify the user's base directory. The default is home.

-e date

Date of validity of user account

-f days

Specify how many days to close the account after the password expires

-g group

Specifies the group of the account, which must exist

-s shell

Specify the shell used by the account

Do not use the-D option

-c comment

Remarks information

-d home

The directory used for each login of the account

-e date

Account termination date, MM/DD/YY

-f days

How long after the account expires?

-g group

Specifies the group of the account, which must exist

-G group

Specify the additional group for the user

-m

If the consumer directory does not exist, it is automatically created

-n

Cancel the group automatically created on the account with the same name

-p password

Set the password for the account

-r

Create a system account

S

Specify the shell used after the account is logged in

-u uid

Specify user ID

3. Files

/ etc/passwd, user account information.

/ etc/shadow, the user account information is encrypted.

/ etc/group, group information.

/ etc/default/useradd, define the information.

/ etc/login.defs, the system generalized setting.

/ etc/skel, which contains the directory of the definition file.

4. Examples

1) create a user

[root@localhost david] # useradd-p 123456 user01 / / create user, password 123456

[root@localhost david] # tail-n 2 / etc/passwd / / check whether it is created successfully

Webalizer:x:67:67:Webalizer:/var/www/usage:/sbin/nologin

User01:x:503:503::/home/user01:/bin/bash

[root@localhost david] # ls / home/ create a home directory under home

David test01 user01 weijie

2) set the user's home directory, uid, and comments

[root@localhost david] # useradd-d / home/other-u 600-c "test user" user02 / / create a user

[root@localhost david] # tail-n 2 / etc/passwd / / View user information

User01:x:503:503::/home/user01:/bin/bash

User02:x:600:600:test user:/home/other:/bin/bash

[root@localhost david] # ls / home/ Home directory other

David other test01 user01 weijie

Thank you for your reading, the above is the content of "the usage of the Linux basic command useradd". After the study of this article, I believe you have a deeper understanding of the usage of the Linux basic command useradd, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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