It seems few use deref overlay. This feature is mentioned on feature list†, but there is no manual for the overlay; only one line is about it in ldapsearch(1) manual. In the last years, only one person mentioned it in 2009 on this mailing list, and his question was unanswered.

I observed this is the way it is supposed to work:

$ ldapsearch -E deref=secretary:sn

Would put the surname of the secretary as the value of 'secretary' attribute.

In reality this search extension errs with a confusing "event not found":

$ ldapsearch -x -E !deref=secretary:sn cn=Betsy secretary bash: !deref=secretary: event not found

A TCP dump shows the surname of the secretary was not mentioned. Here is the data I am experimenting with, very minimalism:

$ ldapsearch -x objectClass=pilotPerson # extended LDIF # # LDAPv3 # base <dc=example,dc=com> (default) with scope subtree # filter: objectClass=pilotPerson # requesting: ALL #

# David, editors dn: cn=David,ou=editors,dc=example,dc=com cn: David objectClass: pilotPerson objectClass: person objectClass: top sn: Jones

# Betsy, editors dn: cn=Betsy,ou=editors,dc=example,dc=com cn: Betsy objectClass: pilotPerson objectClass: person objectClass: top sn: Shwan secretary: cn=David,ou=editors,dc=example,dc=com

# search result search: 2 result: 0 Success

# numResponses: 3 # numEntries: 2

Any hint on how to make it work? Or more importantly, was there anyone using the overlay at all??

Thanks.

P.S. the email subject intends to guide googlers to land in this discussion.

† http://www.openldap.org/faq/data/cache/645.html