Users

Create

On Ubuntu, it is easier to simply use:

adduser patrick

useradd is more primitive:

useradd -g users -s /bin/bash -m patrick
passwd patrick

In this example:

-g

Add to the users group.

-s

Use this shell.

-m

Create the home directory.

Other options:

-u

Force the user ID (UID).

Note

To reject shell login attempts, set the shell to /bin/false. This doesn’t stop the user from using the account to authenticate over ssh. For details see http://www.semicomplete.com/articles/ssh-security/#id54098.

Delete

userdel patrick

Files

Where the user’s name, and other pertinent information are stored. This includes the password unless your system is using shadow passwords:

/etc/passwd

Where group names are stored:

/etc/group

Modify

To modify a users account see the man pages for the usermod command.

To change a users password:

passwd patrick

To change a users group:

usermod -a -G users patrick

In this example, we add patrick to the users group.

Note:

  • Use -g to set the initial login group.

  • The user will be removed from any groups which are not listed.

To change a user ID and group, run the vipw and vipw -g commands. After updating the ID’s you will need to convert existing files to use the correct permissions. The following command will find all files in the home folder owned by UID 500 and pass them to chmod to change to the correct UID for the user name:

find /home -uid 500 -exec chown patrick: "{}" +

See find for more information on the -exec command.

View

To find your user name:

whoami

To view the groups which a user belongs to:

groups username