Path: utzoo!attcan!uunet!lll-winken!csd4.milw.wisc.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!moravian.EDU!nicholaA
From: nicholaA@moravian.EDU
Newsgroups: comp.sys.apple
Subject: Re: Shrink it question
Message-ID: <8903230713.AA26915@batman.moravian.edu>
Date: 23 Mar 89 07:13:52 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 31

>I've used Shrinkit to archive a bunch of files, and a though just occurred to
>me.  If something happens to the file (say a block or half a block goes bad
>for some reason) will I lose _everything_ in the archive or just the file(s)
>that were in that block?

If the bad block occurs in the middle of a data section, the single record
that the bad block occurred in will be damaged, but the rest of the archive
would be OK.  Even though ShrinkIT might stop once it got the IO error after
reading that bad block, you could still selectively extract the files AFTER
the bad record.

*IF* the bad block just *HAPPENS* to fall on top of a header of a record, that
is bad indeed because the headers act akin to a linked list.  If one of the
links gets destroyed, the rest of the archive isn't worth much.  Jason
Blochowiak and myself have discussed writing a sort of "archive recoverer"
which would search through a file that was a damaged NuFX archive and try
to re-construct it, much the way Glen Bredon's "Mr. Fixit" program is supposed
to work on ProDOS disks.

andy

>Kevin Lepard
>Bitnet:  Sasquatch@albion.bitnet
>
----
Andy Nicholas                     CsNET: shrinkit@moravian.edu
Box 435, Moravian College      InterNET: shrinkit%moravian.edu@relay.cs.net 
Bethlehem, PA  18018                     liberty!batman!shrinkit@sun.com
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