Q: search filter to determine if a uid is in a group?

["Eric Merth" <emerth@hotmail.com>]

I have a simple schema with two groups and some users:

dc=com
   dc=company
        ou=people
             cn=web_users            (a posixGroup)
             cn=ftp_users              (a posixGroup)
             uid=emerth                 (a posixAccount)
             uid=...                        (more posixAccounts)

I would like to write a search filter for pureFTPd and one for mod_ldap 
(apache) that
can tell if (1) a user has a posixAccount, and (2) if that user is a member 
of one of the
groups.

I cannot find or derive syntax for a compound filter that, given a uid - say 
'emerth', will
return a non-empty result when 'emerth' exists as a posixAcount and is also 
a member of
a specified group.

I have been trying to turn these two filters into a compound filter with no 
success:

  (&(objectClass=posixAccount)(uid=emerth))
  (&(objectClass=posixGroup)(cn=web_users)(memberUid=emerth))

Is there a different way to determine if a name is in a posixGroup than this 
kind of
filter?


Could anyone help or point me at a good tutorial on writing filters and/or 
search
techniques?

T.I.A.!

Eric

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