Trivially ported to FreeBSD 4.x with only extremely minor tweaks,
largely to adapt to no OPENDEV() on FreeBSD.  For 5.0 and above,
we'll need to teach scan_ffs about multiple MAGIC's for UFS1 vs.
UFS2, fix it to understand the more complex structures and
different constant names, etc.

Make sure to run this tool on the slice, if you use slices, rather
than the disk itself, or all the offsets will be off.  I.e.,

	./scan_ffs ad0s1

as opposed to:

	./scan_ffs ad0

Robert Watson <rwatson@FreeBSD.org>
