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From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: net.sources.bugs
Subject: Re: Beware of Blindly Un-SHARing a File
Message-ID: <979@kitty.UUCP>
Date: Sun, 20-Apr-86 23:19:13 EST
Article-I.D.: kitty.979
Posted: Sun Apr 20 23:19:13 1986
Date-Received: Sat, 26-Apr-86 03:54:50 EST
References: <947@kitty.UUCP> <403@ukecc.UUCP>
Organization: Recognition Research Corp., Clarence, NY
Lines: 22
Keywords: ``Relink'' April Fool
Summary: Don't most ports of UNIX zero disk blocks after an unlink(2)?

In article <403@ukecc.UUCP>, edward@ukecc.UUCP (Edward C. Bennett) writes:
>> 
>>         Part of the joke was funny, and part of it was not so funny.  Anyone
>> naive enough to believe that a deleted file could be recovered was well
>> fooled by the introductory remarks and the phony manual page.
> 
> 	But you can recover an unlinked file! I know, I've had to do it.
> You must unmount the file system and search the free list for your data.
> It's a PITA, but worth it if you lose something big.

	I don't claim to be a UNIX internals expert (I have enough trouble
writing I/O drivers :-) ), but don't most ports of UNIX zero disk blocks after
an unlink(2)?  As I seem to recall, unlink(2) is derived from unlink.s, which
is assembly language specific for the given machine.  And unlink.s contains
a routine _unlink which fills the disk blocks with .word defined as 0x0000.
	Any comments from those who know more?

==>  Larry Lippman @ Recognition Research Corp., Clarence, New York
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