Apple - How can I list all user accounts in the terminal?

How about

dscacheutil -q user | grep -A 3 -B 2 -e uid:\ 5'[0-9][0-9]'

Try this one. I used it to find lost hidden account.

dscl . list /Users | grep -v '^_'

User accounts since 10.6 are being managed by OpenDirectory. The backend files related to users for OpenDirectory are here:

/var/db/dslocal/nodes/Default/users

Executing ls * in this directory will enumerate all local users registered on the system. Executing plutil -p <file>.plist will allow you to read some properties for specified user account (i.e. current home directory path).

This is rather undocumented so I accept downvotes. However, this method can be used to inspect a system which is not running, and for which the user has only an offline disk image.