How to add/remove users, change password, create, edit groups and create sudo user on Debian linux?

List all local users

cat /etc/passwd

You could also use the following command to print only the username part of the above /etc/passwd output.

cut -d: -f1 /etc/passwd

The above parameters: -d: use colon as the delimeter, -f1 get the first field.

 

You must be root for the following

su
 

Add new user

adduser username

Remove user

userdel username

User directory need to be deleted separately if required

rm -r /home/username

Edit username

usermod -l {new username} {old username}
 

Change password

passwd username
 

Create group

groupadd groupname

Add user to group
usermod -a -G groupname username

List all groups current user belong to

groups

List all groups

cut -d: -f1 /etc/group
 

Create sudo user

usermod -aG sudo username

Test sudo user

sudo ls -la /root

The above only works for root/sudo user

You will require to input the user password for the 1st time

 

If sudo command does not work you will need to install sudo package

apt install sudo