usermod

Change a user, for example add them to a group

What it does

usermod changes the settings of an existing user. Most often, their supplementary groups: -aG docker anna adds anna to the docker group so she can run containers without sudo.

New groups take effect from the next login: the user has to log in again or reconnect over SSH. groups <user> shows which groups a user is in.

Careful. Without -a, -G does not add but replaces the list of groups: the user drops out of all the others, sudo included. Always type -aG together.

Syntax

sudo usermod -aG <group> <user>
groups <user>

Examples

• Add the user anna to the docker group, keeping anna in the other groups

  sudo usermod -aG docker anna

  same as: sudo usermod -a -G docker anna, sudo usermod --append --groups docker anna

  • usermod — change a user
  • -a — add to the groups instead of replacing them
  • -G docker — a supplementary group
  • anna — who

Related commands

• adduser — Create a new user
• chown — Change the owner and group of a file or folder
• whoami — Find out which user you are working as

Practise · All commands