Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!clyde!rutgers!seismo!munnari!moncskermit!goanna!yabbie!rcodi
From: rcodi@yabbie.UUCP
Newsgroups: comp.unix.wizards
Subject: Re: rm with a block scrub
Message-ID: <505@yabbie.oz>
Date: Fri, 22-May-87 00:23:17 EDT
Article-I.D.: yabbie.505
Posted: Fri May 22 00:23:17 1987
Date-Received: Sat, 23-May-87 08:39:24 EDT
References: <7421@brl-adm.ARPA> <6899@alice.UUCP> <520@unisec.usi.com>
Organization: RMIT Comm & Elec Eng, Melbourne, Australia.
Lines: 14

In article <520@unisec.usi.com>, dpw@unisec.usi.com (Darryl P. Wagoner) writes:
> Before you go out "scrubbing" the file with zeros make sure it is the
> last link or you will find yourself with a file that has been
> wiped clean.  Could have some very bad results if it was say, ptmp.
 
Also, if the file was a random file (ie: may have holes in it),
you could easily run out of disk space whilst writing trash into it
unless you only wrote trash into blocks that read as non-zero (ie:
those blocks that were never allocated but are below the file size).

A kernel implementation could do that much more efficiently, since
it knows where the holes are.

Ian D.