How to find out what group a given user has?

Question

In Unix/Linux, how do you find out what group a given user is in via command line?

Answer 1

id user

# for example:

id root

Answer 2

Most Unix and Linus distributions provide a command called "groups".

With no parameters, it simply returns the name of the groups assigned to the current user. Optionally you can specify a user name as the first and only parameter to the groups command, which will show all groups assigned to that user.

For example, the following displays all groups assigned to you

$ groups

anyuser adm sudo lpadmin

$

The following displays all groups assigned to the sys user:

$ groups sys

sys : sys

$