dscl

Get a list of all users’ short names:

dscl . -list /Users

Get detailed user info on a particular user:

dscl . -read /Users/

Get a particular value in a user’s info:

dscl . -read /Users/ 

Example of are UniqueID

Get detailed user info for all users:

dscl . -readall /Users

Get a particular value in all users’ info:

dscl . -readall /Users