In Linux, granting a user the ability to run commands with superuser (root) privileges is often necessary for administrative tasks. This is done by configuring the sudoers file. If you encounter the error message "user is not in the sudoers file," follow this step-by-step guide to add your user to the sudoers file using root access.

1.Switch to the Root User

If you have the root password, you can switch to the root user by entering the following command:

su -

You will be prompted to enter the root password. After entering the password, you will have root access.

2. Edit the Sudoers File

Use the visudo command to safely edit the sudoers file. The visudo command opens the file in a text editor and checks for syntax errors before saving the changes.

visudo

3. Add the User to the Sudoers File

In the editor, add a line at the end of the file to grant sudo privileges to the user. Replace username with the actual username you want to add:

username ALL=(ALL:ALL) ALL

This configuration allows the specified user to execute any command as any user.

4. Save and Exit

Depending on the text editor used by visudo, follow the appropriate steps to save and exit:

• If visudo uses nano, press Ctrl + X, then Y, and Enter to save and exit.
• If visudo uses vi or vim, press Esc, type :wq, and press Enter to save and exit.

5. Verify the Changes

After adding the user to the sudoers file, verify the changes by switching back to the regular user and running a command with sudo:

sudo whoami

If the configuration is correct, the command should return root