Source: https://xkcd.com/149/
Introduction
sudo is a program for Unix-like computer operating systems that allows users to run programs with the security privileges of another user, by default the superuser. The name is a contraction of “substitute user do”.
Unlike the related command su, users must supply their own password for authentication, rather than the password of the target user. After authentication, and if the configuration file, which is typically located at /etc/sudoers, permits the user access, the system invokes the requested command. The configuration file offers details access permissions, including enabling commands only from the invoking terminal; requiring a password per user or group; requiring re-entry of a password every time or never requiring a password at all for a particular command line. It can also be configured to permit passing arguments or multiple commands. (Source: Wikipedia)
Installation
First, connect with PuTTY or the Terminal to your environment (see setting up your environment). Then, before installing sudo, we have to become root first:
su
then we can simply install sudo:
pkg install sudo
and finally we have exit the root account:
exit