How to add a new user and a new group in Linux?
Jul 11, 2025 am 01:54 AM
In Linux systems, use the useradd and groupadd commands to add new users and new groups respectively. 1. Add the commonly used commands for users as sudo useradd -m username, where -m creates the home directory, -g specifies the main group, and -s sets the default shell; 2. Add a group to use the sudo group add group name, and then you can specify the group when creating a user through useradd -g group name, or use usermod -aG group name, and existing users to add the existing users to the group; 3. You can view user and group information through groups, groups username, and cat /etc/group to ensure the correct configuration.
In Linux systems, adding new users and new groups is the basic operation in system management. Usually used for permission management and resource isolation in multi-user environments. To complete these two operations, two main commands are used: useradd and groupadd .
Add new users
In most Linux distributions, using the useradd command can create a new user. The basic format of this command is as follows:
sudo useradd [Options] Username
A common practice is to add the -m parameter, which will automatically create a home directory for the user:
-
-m: Creates the user's home directory if it does not exist. -
-g: Specify the main group of the user (must already exist). -
-s: Set the user's default shell, such as/bin/bash.
For example, add a user named alice and create their home directory:
sudo useradd -m alice
If you also want to set a password at the same time, you can run:
sudo passwd alice
You will be prompted to enter and confirm your password.
Add a new group
Use the groupadd command to create a new user group:
sudo groupadd group name
For example, create a group called developers:
sudo groupadd developers
After that, you can add users to this group. There are two ways:
- Specify the group when creating a user:
useradd -g developers newuser - Add existing users to the group:
usermod -aG developers existinguser
Here -aG means "append to the specified additional group", which will not affect the user's existing permissions of other group.
View user and group information
Sometimes you need to confirm whether the user belongs to a certain group, or check whether the group exists. The following methods can be used:
View the group to which the current user belongs:
groups
View the group to which a user belongs:
groups username
View information for all groups:
cat /etc/group
These commands can help you quickly confirm whether the configuration is in effect.
Basically that's it. Although adding users and groups is not complicated, you should pay attention to parameter order and permission control in details, otherwise permission problems or directory ownership errors are prone to occur.
The above is the detailed content of How to add a new user and a new group in Linux?. For more information, please follow other related articles on the PHP Chinese website!
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