groups Command
Beginner User Management man(1)Print group memberships for a user
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📅 Updated: Mar 16, 2026
SYNTAX
groups [USERNAME]
What Does groups Do?
groups displays the group memberships for a user. Without arguments, it shows groups for the current user. With a username, it shows that user's groups.
groups shows the active groups in the current session, which may differ from what is stored in /etc/group if group changes have been made recently (before re-login).
Group membership is fundamental to Linux permissions. Users inherit file access permissions from all their groups, and many services (Docker, sudo) are controlled through group membership.
groups shows the active groups in the current session, which may differ from what is stored in /etc/group if group changes have been made recently (before re-login).
Group membership is fundamental to Linux permissions. Users inherit file access permissions from all their groups, and many services (Docker, sudo) are controlled through group membership.
Options & Flags
| Option | Description | Example |
|---|---|---|
| (no args) | Show groups for current user | groups |
| username | Show groups for specific user | groups www-data |
| multiple | Show groups for multiple users | groups user1 user2 |
Practical Examples
#1 Show my groups
Lists all groups the current user belongs to.
$ groups
Output:
user sudo docker www-data
#2 Show user groups
Shows groups for the www-data user.
$ groups www-data
Output:
www-data : www-data
#3 Check sudo access
Checks if current user has sudo group membership.
$ groups | grep -q sudo && echo "Has sudo" || echo "No sudo"
Output:
Has sudo
#4 Compare users
Shows group memberships for multiple users.
$ groups alice bob
Output:
alice : alice sudo docker\nbob : bob developers
#5 Verify group addition
Adds user to docker group and verifies (must re-login to take effect).
$ sudo usermod -aG docker user; groups userTips & Best Practices
Re-login for changes: Group changes do not take effect in the current session. Log out and back in, or use newgrp groupname.
newgrp for immediate effect: After being added to a group, use newgrp groupname to activate it in the current session without re-login.
groups vs id -Gn: groups shows active session groups. id -Gn shows stored groups from /etc/group. After changes, they may differ until re-login.
Frequently Asked Questions
How do I check what groups I belong to?
Run groups to see your group memberships. Or id -Gn for the same information.
Why am I not in a group I was just added to?
Group changes require logging out and back in. Or use newgrp groupname for the current session.
How do I add myself to a group?
Use sudo usermod -aG groupname $USER. Then log out/in or newgrp groupname.
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