execute a command as another user

change user password

-d, --delete
    Delete a user's password (make it empty). This is a quick way to disable a password for an account.
    It will set the named account passwordless.

-l, --lock
    Lock the password of the named account. This option disables a password by changing it to a value
    which matches no possible encrypted value (it adds a ´!´ at the beginning of the password).

    Note that this does not disable the account. The user may still be able to login using another
    authentication token (e.g. an SSH key). To disable the account, administrators should use usermod
    --expiredate 1 (this set the account's expire date to Jan 2, 1970).

    Users with a locked password are not allowed to change their password.