User Management

usermod Linux Command

Modifies an existing user account (groups, shell, home directory, etc.).

What does usermod do?

Modifies an existing user account (groups, shell, home directory, etc.).

usermod [options] username

sudo usermod -aG sudo john

How do I add a user to a group?

Use `sudo usermod -aG groupname username` to add a user to a group. The `-a` flag appends without removing from other groups.

What does usermod -aG do?

The `-a` flag means append and `-G` specifies supplementary groups. Without `-a`, the user would be removed from all other groups.

How do I change a user's shell?

Use `sudo usermod -s /bin/zsh username` to change the login shell. Use `chsh` as an alternative command.

How do I lock a user account?

Use `sudo usermod -L username` to lock the account. This disables password login while keeping the account intact.

How do I unlock a user account?

Use `sudo usermod -U username` to unlock a previously locked account.

How do I change a user's home directory?

Use `sudo usermod -d /new/home -m username` to change and move the home directory. The `-m` flag moves existing files.

How do I change a user's primary group?

Use `sudo usermod -g groupname username` to set the primary group. This is different from adding supplementary groups with `-G`.

How do I set an account expiry date?

Use `sudo usermod -e YYYY-MM-DD username` to set when the account expires and becomes disabled.

Creates a new user account on the system.

Deletes a user account. Use -r to also remove the home directory.

Changes the password for a user account.

Creates a new group on the system.

Executes a command with superuser (root) privileges.

Deletes an existing group from the system.