How to change my group in linux

How can I change a user’s default group in Linux?

I’ve just finished reading the user administration book in the Linux/Unix Administrator’s handbook, but some things are still a little hazy. Basically useradd seems straight forward enough:

useradd -c "David Hilbert" -d /home/math/hilbert -g faculty -G famous -m -s /bin/sh hilbert 

1. Would this command still work if the groups faculty and famous did not exist? Would it just create them?
2. If not, what command do I use to create new groups?
3. If I remove the user hilbert and there are no other users in those groups, will they still exist? Should I remove them?
4. After I run the useradd command above, how do I remove David from the famous group, and reassign his primary group to hilbert which does not yet exist?

5 Answers 5

The usermod command will allow you to change a user’s primary group, supplementary group or a number of other attributes. The -g switch controls the primary group.

1. If you specify a group, groupname , that does not exist during the useradd stage, you will receive an error — useradd: unknown group groupname
2. The groupadd command creates new groups.
3. The group will remain if you remove all users contained within. You don’t necessarily have to remove the empty group.
4. Create the hilbert group via groupadd hilbert . Then move David’s primary group using usermod -g hilbert hilbert . (Please note that the first hilbert is the group name and the second hilbert is the username. This is important in cases, where you are moving a user to a group with a different name)

You may be complicating things a bit here, though. In many Linux distributions, a simple useradd hilbert will create the user hilbert and a group of the same name as the primary. I would add supplementary groups specified together using the -G switch.

thanks. if i do usermod -g hilbert hilbert will that remove hilbert’s other groups? If so, how would I keep those other groups?If not, wow would I remove him from his other groups?

@MIck’s answer gets my upvote because he points out that you need to use -a with -G (otherwise any group you leave off will be removed)

You need to read the man usermod which explains what happens with the various options:

will replace your login group from ‘faculty’ to ‘hilder’, as long as the group ‘hilder’ exists. If it doesn’t exist then you first need to create it with groupadd.

When you use the -G option you should also use the -a option to append new groups to the current list of supplementary groups that user ‘hilder’ belongs. Without the -a option you will replace current supplementary groups with a new group set. Therefore use this cautiously.

To change a user’s primary group in Linux:

• usermod -g new_group user_name
• terminate alluser_name‘s active sessions

To test your changes run id and look at the value of gid=

If the command runs without errors but the gid hasn’t change you’ve missed the bold part of step 2.

answer #1 is good, still you could also choose to issue the following to add a new group:

The downside of editing /etc/group directly is that you will have to come up with an unused GID (group ID number).

The following will allow you to change the primary group of a user. # nano /etc/passwd

You locate the line of the user, and change the GID (group number, look it up in /etc/group ), keep in mind that the syntax is as follows:

There is no downside I can think of to this approach (provided you know the GID), it is what I frequently use for local users, mainly because I use many different UNIX systems with differing usermod , adduser , and useradd command options.

It is a bit more manual, however does the job. Note that you can use vi iso nano to edit the files, if you know vi .

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Chgrp Command in Linux (Change Group)

To change the group ownership of a file or directory invoke the chgrp command followed by the new group name and the target file as arguments. If you run the command with an unprivileged user, you will get an “Operation not permitted” error. To suppress the error message, invoke the command with the -f option.

1. How do I switch groups in Linux?
2. How do I change the owner of a group?
3. How do I change my primary group in Linux?
4. How do I change the user and group of a file in Linux?
5. How do I find groups in Linux?
6. How do I change my current group?
7. How do I change owner in Linux?
8. How do I change the owner of a group recursively in Linux?
9. What is Sudo Chown?
10. How do I remove a primary group in Linux?
11. How do I list all groups in Linux?
12. How do I change a secondary group in Linux?

How do I switch groups in Linux?

chgrp command in Linux is used to change the group ownership of a file or directory. All files in Linux belong to an owner and a group. You can set the owner by using “chown” command, and the group by the “chgrp” command.

How do I change the owner of a group?

To change a group’s owner, use the pts chown command. To change its name, use the pts rename command. You can change the owner or name of a group that you own (either directly or because you belong to the owning group). You can assign group ownership to another user, another group, or the group itself.

How do I change my primary group in Linux?

To set or change a user primary group, we use option ‘-g’ with usermod command. Before, changing user primary group, first make sure to check the current group for the user tecmint_test. Now, set the babin group as a primary group to user tecmint_test and confirm the changes.

How do I change the user and group of a file in Linux?

The chown command allows you to change the user and/or group ownership of a given file, directory, or symbolic link. In Linux, all files are associated with an owner and a group and assigned with permission access rights for the file owner, the group members, and others.

How do I find groups in Linux?

In order to list groups on Linux, you have to execute the “cat” command on the “/etc/group” file. When executing this command, you will be presented with the list of groups available on your system.

How do I change my current group?

The newgrp command is used to change the current group ID during a login session. If the optional — flag is given, the user’s environment will be reinitialized as though the user had logged in, otherwise the current environment, including current working directory, remains unchanged.

How do I change owner in Linux?

1. Become superuser or assume an equivalent role.
2. Change the owner of a file by using the chown command. # chown new-owner filename. new-owner. .
3. Verify that the owner of the file has changed. # ls -l filename.

How do I change the owner of a group recursively in Linux?

To recursively change the group ownership of all files and directories under a given directory, use the -R option. Other options that can be used when recursively changing the group ownership are -H and -L . If the argument passed to chgrp command is a symbolic link, the -H option will cause the command to traverse it.

What is Sudo Chown?

sudo stands for superuser do. Using sudo , the user can act as a ‘root’ level of system operation. Shortly, sudo gives user a privilege as a root system. And then, about chown , chown is used for setting the ownership of folder or file. . That command will result in user www-data .

How do I remove a primary group in Linux?

1. We can use gpasswd to remove user from group.
2. But if a user is part of multiple groups then you need to execute gpasswd multiple times.
3. Or write a script to remove user from all the supplementary groups.
4. Alternatively we can use usermod -G «»

How do I list all groups in Linux?

To view all groups present on the system simply open the /etc/group file. Each line in this file represents information for one group. Another option is to use the getent command which displays entries from databases configured in /etc/nsswitch.

How do I change a secondary group in Linux?

1. To create a new group, enter the following: sudo groupadd new_group. .
2. Use the adduser command to add a user to a group: sudo adduser user_name new_group. .
3. To delete a group, use the command: sudo groupdel new_group.
4. Linux comes with several different groups by default.

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How to change my current unix group

I belong to several user groups (say coder, projectmanager, sudo), for some reason I may not be in a particular group. This happens when I am in a particular directory that belong to a particular group where I need the write access to create new files. It is quite annoying that I am in a different group. When I run the groups command, I am listed as in groupA, how do I become groupB? When I do a search, the top link goes to how to create groups.

2 Answers 2

If you’re an admin, just do it as root or as a user with the appropriate permissions.

If you’re trying to avoid that, you can add yourself to the group. Most systems will let you do that with a simple command:

sudo usermod -a -G newgroup username 

Older systems require editing /etc/group . First try sudo vigr («vi group,» much like vipw for the passwd file) and if that isn’t present, you may edit it directly via sudo vi /etc/group .

Find the relevant group and append yourself to it. Users are in the last colon-delimited section and are comma-delimited within that section. For example, you can add yourself to the «cdrom» and «games» groups:

root:x:0: users:x:100:kemin cdrom:x:24: games:x:60:adam 

root:x:0: users:x:100:kemin cdrom:x:24:kemin games:x:60:adam,kemin 

A very quick programmatic approach —which lacks safeties— could look like:

sudo sed -i '/^games:/s/$/,kemin/; s/:,/:/g' /etc/group 

I only added one safety above, which accounts for an empty group (no comma needed). This does not check to ensure you’re initially absent from the group, and I didn’t use a regex alternation ( /^\(games\|cdrom\):/… ) because non-GNU sed doesn’t support it.

(This may not work on systems that lock /etc/group to vigr. The fact that it’s hard to get all the safeties correct is why such locking is justified.)

This will not immediately work! You need to log out and log back in, or else sudo as yourself (which is a good way to test without the hassle of logging out), e.g. sudo -u $USERNAME groups , or get a new login through a virtual terminal ( Alt + F2 ) or something like ssh localhost .

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How To Change User Group In Linux?

Linux users are assigned to different groups to get different permissions. A single user may have single or multiple groups. In this tutorial, we examine how to change user groups in Linux operating system.

Linux Group Types

There are two types of Linux Groups. First is the primary group which is generally the same as the user. The primary group is used when the user creates a file or folder the primary group is assigned as the group for the created file or folder. The second group type is the second group which is mainly used to provide permission for other files and folders to access.

Display User Groups

A user may have single or more groups. These groups can be listed by using the groups command like below.

ismail adm cdrom sudo dip plugdev lpadmin lxd sambashare wireshark

Change Primary Group

The primary group can be changed with the usermod command. The -g option is used to provide the primary group name to be set. The syntax of the usermod command is like below.

usermod -g PRIMARY_GROUP USERNAME

• PRIMARY_GROUP is the group name we want to change.
• USERNAME is the user we want to change.

In the following example, we set the user “ismail” secondary group as “admin”.

Change Secondary (Other) Group

The secondary group of a user can be changed using the -G option. This is also called changing another group of users. The -G option is used to specify the secondary group to add for the user. Also, the -a option is used to add a new secondary group. In the following example, we set the secondary group of the “ismail” as “editor”.

Change Multiple Groups

The usermod command can be also used to set multiple secondary groups for a user. The multiple group names are provided with the -G option of separating all group names with a comma. In the following example, we set multiple user groups for the user “ismail”.

$ usermod -a -G admin,editor,superadmin ismail

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