Add User Account

The simplest way of creating a new user account in Linux is with the help of useradd. This utility offers various parameters to specify additional information while adding a new user. Some of the options are:

  • -c: Adds description/comment to a user account. 
    •   useradd -c "John Wise" john
  • -d: Sets the home directory for the specified user. By default, the useradd command sets it to the username (/home/john), but you can replace it with the directory of your choice as follows: 
    •   useradd -d /mnt/home/john
  • -g: Allows you to set the primary group of a user. The user will be added to a group by default if you don’t add one during the creation process.
  • -G: Adds the user to multiple groups. 
    •   useradd -G juice,apple,linux,tech john
  • -o: Creates a new user account using the UID of an existing user.
  • -p: Used to add an encrypted password to the account. You can also add your password later using the following command:
    • passwd john


For instance, here’s how you can use the useradd command and some of the above parameters to add a new user:

useradd -g tech -G apple,linux -s /bin/zsh -c "James Adem" adem


In the user creation process, the aforementioned command performs several actions:

  • Sets tech as the primary group of the user
  • Sets Zsh as the default shell for the user
  • Adds adem to the apple and linux groups. This operation also creates new entries inside the /etc/group file.
  • Sets /home/adem as the default home directory
  • Creates new entries inside the /etc/passwd and /etc/shadow files. The command adds the following line to the /etc/passwd file: 
    • adem:x:1002:1007:James Adem:/home/sara:/bin/zsh

Modify User Account

usermod is another simple yet straightforward Linux utility to modify user account details. It supports similar parameters or flags as the useradd command and that’s why its usage is quite simple.

For instance, you can change the default shell of the user adem from /bin/sh to /bin/bash as follows:

usermod -s /bin/bash adem


Now to include adem in the sales group, you’ll need to use the -aG flag as a simple -G flag will remove the user from the previously added supplementary groups: apple and linux.

usermod -aG sales adem
cat /etc/group | grep adem

Change user password

To change a user’s password, you can just run:

sudo passwd -l 'username'


Delete User Account

Linux offers another command-line utility userdel to delete any user account. Here’s the basic syntax:

userdel username


However, it will only remove the account details from the /etc/passwd file. To remove the user’s home directory as well, use the -r flag, as follows:

userdel -r username

As a precaution, we recommend finding all the files owned by the user and reassigning them to any other existing user account. Use the find command to list all the files either owned by the user or assigned to a user ID you have removed or not associated with any user.

find / -user username -ls
find / -uid 504 -ls
find / -nouser -ls