David Cannings: > Thomas C. Greene wrote: > > I've posted the final versions of a few simple, free shell scripts that i've > > been working on to make data hygiene more convenient on *nix systems. Thanks > > to list members who helped test them and contributed improvements. > > Is there any specific advantage of these scripts over bcwipe? > > http://www.jetico.com/index.htm#/bcwipe_unix.htm There's a general problem with applications that go through the file system to destroy the contents of a file. Unless one uses very simplistic disk harware and file systems, there is no guarantee that overwrite requests will actually overwrite the intended bits. For a example, Solaris 10 ZFS uses copy-on-write, to avoid corruption when the system crashes in the middle of an update; many disk drives have write caches built-in so only the last overwrite request takes effect; and non-volatile memory "disks" have a limited number of write cycles and try to avoid hot spots. Wietse
