Ubuntu User add
https://www.digitalocean.com/community/tutorials/how-to-add-and-delete-users-on-ubuntu-16-04
user add
sudo useradd -m sixx
-m, –create-home create the user’s home directory
password
sudo passwd sixx
default shell
sudo chsh -s /bin/bash username
Sudo
sixx계정에 sudo그룹의 권한을 추가
sudo usermod -aG sudo sixx
-G, –groups GROUPS new list of supplementary GROUPS
