[TUHS] History of chown semantics

Brian S Walden tuhs at cuzuco.com
Fri Jan 10 07:29:11 AEST 2014


it follows the philosophy of pwb --  a usable system for disparate small groups
of developers on the same hardware that could be managed by admins not
system programmers.

read http://www3.alcatel-lucent.com/bstj/vol57-1978/articles/bstj57-6-2177.pdf
for the flavor of that time, and you'll understand better.

> From: Clem Cole <clemc at ccc.com>
> 
> Brian - right as I showed in the code snippet from V6 and PWB.  The idea
> came into being with PWB.
> The question that is still open is why was it added/need in the first
> place?    I always thought is was a crazy/miss feature,
> 
> I think the argument is that if you owned the file, you should be allowed
> to give it to anyone else [including root] - but that actions opens up a
> number of issues (you pointed the big security one that was handled by
> and-ing off the SUID/SGID bits).  There are accounting issues as well as
> the practical one that Tim and I pointed out with importing of files on a
> tape.
> 
> As I said, the file give-away feature comes into UNIX with PWB, so I would
> ask Mash is he remembers why it was needed and why the SVID folks wanted
> it.  As I said, I personally found it not useful/a bad idea/miss-feature.
>  I remember that I soon after I learned about it/got bitten by the side
> effect, I ran into dmr  and srb at a USENIX and asked them about that a few
> other System III features that I found a little strange.   I don't remember
> much of the conversation.   But, if there are been a "good" reason I think
> I would have remembered it and not always thought it to be a bad idea.
> 
> Clem



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