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How to rename a user in Linux ​

Introduction ​

In this article, we will learn how to rename a user in Linux. We will also learn how to rename a user's home directory and group.

Prerequisites ​

  • A system running Linux
  • A user account with sudo privileges

Renaming a user ​

For renaming a user, we will use the usermod command. The usermod command is used to modify a user account. We cannot rename a user while the user is logged in. We need to log in as a different user or use the root account to rename a user.

Creating a new temporary user ​

Before renaming a user, we will create a new temporary user. We will use this user to log in and rename the user.

  • To create a new user, run the following command and follow the prompts to set a password for the new user:

    bash
    sudo useradd -m tempuser

    Here the -m option is used to create a home directory for the new user. we can also use the -d option to specify the home directory for the new user. As the user is temporary we don't need to specify the home directory or any other shananigans.

  • Now we need to add the new user to the sudo group so that we can run commands with root privileges. Run the following command to add the new user to the sudo group:

    bash
    sudo usermod -aG sudo tempuser

    Here the -a option is used to append the sudo group to the user's list of supplementary groups. and the -G option is used to specify the group to which the user will be added.

    We can also do the same thing with the following command:

    bash
    sudo adduser tempuser sudo

    This command will add the user to the sudo group.

  • Now we will logout and login as the new user. If we don't have a GUI, we can use the su command to switch to the new user.

    bash
    su - tempuser

    Here the - option is used to start a login shell for the new user. This will load the new user's environment and start a new login session.

Renaming the user ​

Now we will rename the user using the usermod command. Run the following command to rename the user:

bash
sudo usermod -l newuser -m -d /home/newuser olduser

Here the -l option is used to specify the new username. The -m option is used to move the contents of the old home directory to the new home directory. The -d option is used to specify the new home directory for the user.

Renaming the group ​

If we want to rename the group as well, we can use the groupmod command. Run the following command to rename the group:

bash
sudo groupmod -n newgroup oldgroup

Here the -n option is used to specify the new group name.

Verifying the changes ​

We can verify the changes by listing the contents of the /etc/passwd and /etc/group files. Run the following commands to list the contents of the files:

bash
cat /etc/passwd
cat /etc/group

We can also use the id command to verify the changes. Run the following command to display the user and group information:

bash
id newuser

Here the id command is used to display the user and group information for the specified user.

Deleting the temporary user ​

After renaming the user, we can delete the temporary user. Run the following command to delete the temporary user:

bash
sudo userdel -r tempuser

Here the -r option is used to remove the user's home directory and mail spool.

Conclusion ​

In this article, we learned how to rename a user in Linux. We also learned how to rename a user's home directory and group. We also learned how to create a new temporary user and delete the temporary user after renaming the user.