This is diskdump v0.30, a copy program with simple cutting capability.
It has been written for fastly accessing raw harddisks.
In contrast to dd(1) it uses llseek(2)/lseek(2) for this purpose which just
makes the fast access possible.

The usage is:  diskdump [options] [file].

Diskdump is one of a bunch of simple disk utilities (named disk*), which
should be available at the sunsite ftp site (sunsite.unc.edu), probably in
pub/Linux/utils/disk-management.
