dscl . -create /Users/joeadmin
dscl . -create /Users/joeadmin UserShell /bin/bash
dscl . -create /Users/joeadmin RealName "Joe Admin" 
dscl . -create /Users/joeadmin UniqueID "510"
dscl . -create /Users/joeadmin PrimaryGroupID 20
dscl . -create /Users/joeadmin NFSHomeDirectory /Users/joeadmin
dscl . -passwd /Users/joeadmin password 

dscl . -append /Groups/admin GroupMembership joeadmin