Use only one filedescriptor. Open in R/O or R/W based in the '-N' option.
Make the filedescriptor a global variable instead of passing it around
as semi-global variable(s).
Remove the undocumented ability to specify type without '-T' option.
Replace fatal() with straight err(3)/errx(3). Save calls to strerror()
where applicable. Loose the progname variable.
Get the sense of the cpgflag test correct so we only issue warnings if
people specify cpg and can't get that. It can be argued that this
should be an error.
Remove the check to see if the disk is mounted: Open for writing
would fail if it were mounted.
Attempt to get the sectorsize and mediasize with the generic disk
ioctls, fall back to disklabel and /etc/disktab as we can.
Notice that on-disk labels still take precedence over /etc/disktab,
this is probably wrong, but not as wrong as the entire concept of
/etc/disktab is.
Sponsored by: DARPA & NAI Labs.
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