Learn how to manage your linux system with the groupadd command to add groups and useradd to add users.
This blog post will discuss how to use the groupadd command in Linux. This command adds a new group to the system. Understanding how to use this command to manage your Linux system effectively is important. By the end of the post, you will know how to create groups and add users to the groups you make.
Let's get started!
Sudo Privileges
The first step is to open the terminal. You can do this by pressing Ctrl+Alt+T on your keyboard.
You cannot add a group without sudo privileges. Therefore, you must use the Sudo command to gain access or log in as a root user. To do this, type:
sudo -
Enter your password when prompted.
Once you have access, you can manage your system.
groupadd command
We add groups using the groupadd
command, followed by the name of the group you want to add.
The syntax for the command is:
groupadd [options] groupname
Example:
If we wanted to add a group called "geekbits", we would type:
groupadd geekbits
OR: use sudo if not a root user.
sudo groupadd geekbits
To confirm that the group was added successfully, run this command:
cat /etc/group
Output:
redis:x:119:
ssl-cert:x:120:postgres
postgres:x:121:
superman:x:1001:
`geekbits:x:1002:`
As you can see the group "geekbits" was added successfully.
Creating Users : Useradd command
To create a user, we use the useradd
command followed by the user's name.
The syntax is as follows:
useradd [username]
Example
sudo useradd grandmaster
Let's confirm the user add was successful.
cat /etc/passwd
Output:
j4y:x:1000:1000:,,,:/home/j4y:/bin/bash
redis:x:112:119::/var/lib/redis:/usr/sbin/nologin
postgres:x:113:121:PostgreSQL administrator,,,:/var/lib/postgresql:/bin/bash
superman:x:1001:1001::/home/superman:/bin/sh
`grandmaster:x:1002:1003::/home/grandmaster:/bin/bash`
Now that the user "grandmaster" was added successfully, Let's see how to add users to groups.
Adding users to a group
New user:
To add a new user to a group, we use the useradd
command with -G
flag followed by the group's name and then the user's name.
The syntax is as follows:
useradd -G [group name] [username]
Example
sudo useradd -G geekbits jeff
Output:
ssl-cert:x:120:postgres
postgres:x:121:
superman:x:1001:
geekbits:x:1002:`jeff`
As you can see, the geekbits group has a new user "jeff."
Existing user:
We add existing users to a group using the usermod
command.
The syntax is as follows:
usermod -G [group name] [username]
Example
sudo usermod -G geekbits grandmaster
We use the -G
option to specify the group to which we want to add the user.
Output:
ssl-cert:x:120:postgres
postgres:x:121:
superman:x:1001:
`geekbits:x:1002:jeff,grandmaster`
And that's it! You have successfully added a new group to your Linux system (geekbits) and added users (jeff, grandmaster) to the group.
Remember, you can only add groups if you have sudo privileges or be logged in as root. If you need help managing your groups, feel free to contact us for assistance. We're always happy to help!
Thanks for reading:)