the utmp.h header file

The program qbiff from the qmail package uses the header utmp.h, which
houses the declaration of various structures needed to use the login
database in systems that are perhaps not FreeBSD.  The program qbiff.c
doesn't compile because it can't find utmp.h.

It seems FreeBSD has either evolved the system to use utmpx.h or perhaps
it never used the utmp.h header we perhaps find in GNU systems.  I've no
idea.

I'm wondering if there's anything easy that can be done so that qbiff
would compile and work correctly.  Just making a symbolic link from
utmp.h to utmpx.h wouldn't suffice because all structures defined by
utmpx.h in FreeBSD have different names.  So perhaps I'm out of luck.

By the way, I'm not really interested in qbiff.  On the contrary, I'm
more interested in understanding FreeBSD with regard to this
compatibility question involving other systems.