Adding a new user to a Mac:
sudo dscl localhost -create /Local/Default/Users/username
sudo dscl localhost -create /Local/Default/Users/username UserShell /bin/bash
sudo dscl / -create /Local/Default/Users/username RealName "User Name"
sudo dscl localhost -create /Local/Default/Users/username RealName "User Name"
sudo dscl localhost -create /Local/Default/Users/username UniqueID 555
sudo dscl localhost -create /Local/Default/Users/username PrimaryGroupID 555
sudo dscl localhost -create /Local/Default/Users/username PrimaryGroupID 20
sudo dscl localhost -create /Local/Default/Users/username NFSHomeDirectory /Users/username
