As discussed in ITS #3737, I'm going to write a new backend based upon
back-passwd (calling it "back-posix" for want of a better name), but
before I do so I want to make sure that I won't be wasting my time by
having to throw everything out and starting again.
Our objective here is to provide a single search against multiple sources
including /etc/passwd, so back-posix would slot underneath back-meta. It
would be as general as possible whilst catering for our needs, hence the
I've browsed the archives noting the points therein, especially the
threads openldap-devel/199901/msg00035 and openldap-devel/199903/msg00011,
and ITS #40.
Returns objectClass inetOrgPerson/posixAccount, with as many attributes as
I can find or infer, as uid=pw_name :
cn: Set from pw_name (configurable? )
gidNumber: Set from pw_gid
homeDirectory: Set from pw_dir
sn: Inferred from pw_gecos 
uid: Set from pw_name
uidNumber: Set from pw_uid
description: Set from pw_gecos (up to first comma?)
gecos: Set from pw_gecos
givenName: Set from first token in pw_gecos (or pw_name if "&")
loginShell: Set from pw_shell
userPassword: Set from pw_passwd 
Other optional attributes (which we don't use):
host: It's only in "account" 
l: Set from getdomainname()
mail: Set from pw_name @ domain
telephone: Extract from pw_gecos 
Other considerations (which definitely won't be in the first cut):
Remove the serialisation.
Implement some form of cache.
 Or configurable, as long as it's a required attribute.
 I prefer my configuration options to be set at run time, not
compile time, wherever possible. Other options include returning
pw_gecos instead, or givenName+sn?
 Take everything before first "," and then all but first token,
perhaps skipping what looks like initials.
 Probably useless in a shadowed environment.
 But could be a configurable option...
 How portable is this field, as Howard noted? On FreeBSD at
least, it's full name, office, work phone, home phone. One
whacky idea could be "gecos l,telephoneNumber,homePhone" i.e.
parse the stuff after the first comma into those attributes.