Adicionar usuário ao grupo
usermod -a -G examplegroup exampleusername
Black Beaver
usermod -a -G examplegroup exampleusername
sudo usermod -aG <groups> <username>
sudo usermod -aG groupName userName
# restart or just run
newgrp groupName
User: the owner of the file (person who created the file).
Group:the group can contain multiple users. Therefore, all users in that group will have the same permissions. It makes things easier than assign permission for every user you want.
sudo dseditgroup -o edit -t user -a <user> <group> # OSX
useradd -mg [groups] [username]