Finding all user groups without knowing how groups are defined

["Fu, Jing" <jing_fu@atlanta.stercomm.com>]

Is there a way for a generic software to enumerate all the user groups in a
directory, without knowing how the groups are defined and how the directory
is structured?  I read from somewhere that there are at least 4 different
schemes of defining user groups (or whatever groups):

	1. Let each ou double as a group.
	2. Represent each group as a groupOfNames or groupOfUniqueNames
object, and the group object has a list of attributes that indicates the
group members.
	3. put a memberOfGroup attribute in each member of the group
	4. Define groups based on dynamic search rules

And these schemes may be combined or used in parallel.  Of course some
schemes may turn out to be better than the others, but I'd assume each has a
large number of followers.  Since I will have no influence to and no
knowledge of how my customers would configure their directories, I want to
make my program as general and adaptive as possible in terms of user groups.
But it seems to be quite a mess, and I'm still not sure where I should
start.  Any suggestions?

Another question is, how can I tell, efficiently, if a group is for users or
for something else like printers or other resources?

Thanks,
Jing