When I’m setting up a linux system, since it’s not very often, I have to keep looking up the basic commands for user setup.

I had started putting them in a text file and now it’s reached here!

All following commands to be run as root

if no network

Edit /etc/network/interfaces and add the following:

auto eth0
allow-hotplug eth0
iface eth0 inet dhcp

install sudo

apt-get install -y sudo

change default visudo editor

update-alternatives --config editor

Full details here

enable wheel group

This is a handy group for when you want the user to access root without a password.

  1. Via visudo, enable the following
%wheel ALL=(ALL) ALL

2. Edit /etc/pam.d/su. Uncomment the following line

auth	sufficient pam_wheel.so trust

new user

Reference: AskUbuntu

create user with prompts
adduser <username>
create user with explicit settings
useradd <username>
create a new user without a group
useradd <username> --gid nogroup
create a new user without a shell
useradd <username> --shell /bin/false
Create new user with auto-create home directory
useradd -d /home/<username> -m <username>
Delete a user
deluser <username>
Delete a user with auto-delete home directory (and mail spool)
deluser --remove-home <username>

new group

Add a new Group
groupadd <groupname>

e.g.

groupadd wheel
Add existing user to existing group
usermod -a -G <groupname> <username>
Remove existing user from group
deluser <username> <groupname>
to check groups which a user belongs to
groups <username>