User & Group Management

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Adding Users

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Adding Users

To add a user, the useradd command can be used.

useradd username

If you want to create a user with it's own home directory, this can be done using the -m flag:

useradd -m username

The default contents of a users home directory are defined within the /etc/skel directory, please see HERE for more info on this.

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Additional options:

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Groups

When creating a user, you can also specify groups to add the user to, this is done using the -G flag:

useradd -G groupname username

Comments

When creating a user, you can also opt to add a comment using the -c flag, for example this could be a name:

useradd -c "comment" username

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Passwords

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Set Password

Once a user has been created, you can add a password using the passwd command:

passwd username

Once run, you'll be prompted to enter a new password

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Changing password

Changing a users password can be done using the passwd command when signed in as that user.

You can either SSH to the server directly using the required user, or access as root and use su- username to access the user. Once accessed, the passwd command can be run alone to change the password:

passwd

You can also change a users password using root:

passwd username

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Additional Options:

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Temporary Password

When setting a password, you're able to set a temporary placeholder password that can be used to log in by the user, upon logging in the user will be prompted to change to a password of their choice. This can be achieved by using the -e flag after setting a password

passwd username #set as temp password

passwd -e #sets password as expired

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Deleting Users

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Deleting Users

Users can be deleted using the userdel command:

userdel username

The above command only removes the user from the system, without removing their home directory.

Remove user and home directory

userdel -r username

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Groups

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Viewing Groups

groups username

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Adding Groups

New groups can be created using the groupadd command:

groupadd groupname

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Managing group users

Users can be added to a group with 2 main methods, 

1. They can be added when initially created, as mentioned above
2.  They can be added after creation, using the usermod command:

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Removing groups

Groups can be removed using the groupdel command, note that this doesn't delete the users that are part of this group.

groupdel groupname