[sudo-users] Defaults:user

[Victor Engle]

I read the man page but I'm a little confused about the format for
Defaults:user. In particular, I want to be able to parse the line, pull out
the users and validate them, then reconstruct the line minus invalid users.

If a list of users is specified how are the users in the list delimited and
how is the user list delimited from the parameter at the end of the entry?

Thanks for any help.
Thanks!
Vic