Use following command to edit the sudoer file
$ sudo visudo
The sudo command is configured through a file located at /etc/sudoers.
Note: Never edit this file with a normal text editor! Always use the visudo command instead!
Because improper syntax in the sudoers file can leave you with a system where it is impossible to obtain elevated privileges, it is important to use the visudo command to edit the file.
How To Modify the Sudoers File
use the visudo command to open the file, and file the following line
## Allow root to run any commands anywhere
root ALL=(ALL) ALL
add user ALL=(ALL) ALL following the root ALL=(ALL) ALL line
If you want the sudo command without password, you can change the command to
user ALL=(ALL) NOPASSWD:ALL
If you want to add the whole group to sudoer, you can change the command to
user ALL=(ALL:ALL) ALL
