How to Add User to Group in Linux
This post will guide you how to add new and existing users to primary or secondary groups in your Linux Operating systems. How do add a user to a group in Linux. How to remove a user from a group. How to create or delete a Group.
- Adding a User to a Group
- Adding a User to Multiple Groups
- Removing a User from a Group
- Creating a Group
- Deleting a Group
- Changing the Primary Group of a User
Adding a User to a Group
If you want to add an existing user to a secondary group, and you can use the usermod command with -G option.
For Example, if you want to add a user called mytest to another group(mydev), just type:
$ sudo usermod -a -G mydev mytest
You can verify if the secondary group of this user is added, type:
$ id mytest
Outputs:
devops@devops:~$ id mytest uid=1001(mytest) gid=1001(mytest) groups=1001(mytest),1002(mydev)
Adding a User to Multiple Groups
If you want to add an existing user to multiple secondary groups in your Linux, and you can use usermod command with -G option and names of group separated by common character.
For example, you want to add user mytest to multiple groups(mytest2,mytest3), type:
$ sudo usermod -a -G mytest2,mytest3 mytest
Let’s check if user “mytest” is added to multiple groups by using the following command:
$ id mytest
Outputs:
devops@devops:~$ id mytest uid=1001(mytest) gid=1001(mytest) groups=1001(mytest),1002(mydev),1003(mytest2),1004(mytest3)
Removing a User from a Group
If you want to remove a user from a group, and you can use the gpasswd command. For example, you want to remove a user called mytest from a group called mytest3. Type:
$ sudo gpasswd -d mytest mytest3
Outputs:
devops@devops:~$ sudo gpasswd -d mytest mytest3 Removing user mytest from group mytest3 devops@devops:~$ id mytest uid=1001(mytest) gid=1001(mytest) groups=1001(mytest),1002(mydev),1003(mytest2)
Creating a Group
If you want to create a new group in your current Linux system, and you can use the groupadd command with a group name(mytest4), type:
$ sudo groupadd mytest4
Deleting a Group
If you want to delete an existing group, and you can use the groupdel command with a group name, type:
$ sudo groupdel mytest4
Changing the Primary Group of a User
If you want to change a user primary group, and you can use the usermod command with -g option.
For example, you want to change the primary group from mytest to mytest4. Just issuing the following command:
$ sudo usermod -g mytest4 mytest
Outputs:
devops@devops:~$ sudo usermod -g mytest4 mytest devops@devops:~$ id mytest uid=1001(mytest) gid=1005(mytest4) groups=1005(mytest4),1002(mydev),1003(mytest2) devops@devops:~$
If you want to get more information about both useradd and usermod commands, and you can type the following man command at the shell prompt:
$ man usermod $ man useradd $ man groupadd
Conclusion
You should know that how to add a user to a secondary group or multiple groups in your CentOS or RHEL or Ubuntu Linux.
