How do I add a user to multiple groups in Ubuntu?

Question

What's the command line utility and the arguments it requires?

Solution 1

The utility is usermod and is used like:

usermod -a -G group1,group2 username

Where username is the user you want to modify and group1 and group2 are the new groups you want that user to join. Running the command without the -a argument will remove that user from all groups except group1 and group2.

To check a users group memberships use the groups command:

groups username

Solution 2

usermod -a -G group1,group2,group3 username

Solution 3

Assuming the user already exists, the easiest way is to just open the file /etc/group and add the username to the relevant groups that you want them to be a member of. The usernames are comma separated from the other usernames in the group.

You can check by doing a id -G username to verify if they are members of the groups you intended.

Solution 4

On Debian, and I assume on Ubuntu as well, the canonical way of adding users and adding users to groups is through the adduser script, not useradd. To add a user to a group, just use:

adduser user group

Though using useradd or usermod works as well of course and is probably more cross platform (but the adduser script reads settings from /etc/adduser.conf and is hence usually preferable).

Solution 5

Use usermod with the -a and -G options.

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Comments

[Gauthier]

"How do I add a user to multiple groups in Ubuntu?"

[wds]

@Gauthier run the above twice, once for each group. I figured that was obvious.

[Ariel]

Obviously you can run a command to add a user to a single group twice, but given the way the question is phrased I would expect any answer to explain how to add a user to two groups using a single command once.

[Admin]

This is completely unrelated to the question asked.