[Sussex] UC!

[Steve Dobson]

Geoff

On 08 July 2003 at 08:08 Geoff Teale wrote:
> On Tuesday 08 July 2003 7:32, Steve Dobson wrote:
> > What out here, this is dangerous.  The Open Group, the trademark holders
of
> > "Unix",
> > don't like statements like "Linux is like Unix", in fact I seam to
recall
> > that they
> > are taking Apple to court over Apple's use of the term "Unix".
> >
> > It is much safer (the Open Group can't do anything about it) is to say
the
> > "Unix is
> > like Linux".
> 
> Mmmm, yes.  Linux is an implementation of a Unix like 
> operating system, this much we know for sure.  

I'm with you 100% so far.

> Whether it _is_ actually Unix or not is a more difficult question.   

I think not - but more for legal reasons than technical.

> (Unless you believe SCO,) Linux doesn't contain any of the actual Unix
code, 
> but it does contain a lot of it's concepts (structurally it is deliberatly

> almost exactly a Unix clone).  However, this in itself is not necessarily 
> enough to call it Unix, many OS that are definitely not Unix are very
close - 
> BeOS, QNX, etc... even, in some respects, Windows (certainly DOS was
inspired 
> by Unix, even if it was a legendarily poor implementation).

I don't think common code matters.  Just because the same bit of code is in
two
different programs does not make them the same.  But yes, the internal
structures
are very similar.  And yes, that does not make them a Unix clone. 

Was DOS really inspired by Unix?  The big competitor in the small personal
computer
space at the time was CPM.  I do think that good utilities get passed
around, so
some utilities crop up all over the place.  So later version of DOS may have
had
some utilities that would be familiar to a Unix person.

> So the difficulty here is what defines something as actually being Unix -
is 
> there a clear definition?

Yes - there is a set of tests that can be applied.  I think this was done
once
for Linux and it passed.  However, this is an expensive process, and the
rate
at which new code is added to Linux (or *BSD) means that it is never likely
to be
tested against the Unix spec very often.

> Most people agree that *BSD are Unix, yet since the court case in the
early 
> 1990's they, like Linux, share no source code with AT&T's offspring.

I think *BSD also has the same cost barrier with the Unix standard.

> What about Mach (the core of Apple Mac OS X)?  Certainly it was always 
> referred to as "a microkernel Unix" when I was a lad (and all this were 
> fields, yer know)  - but know people are doubting Apple's claims that
Darwin 
> (which is a combination of the Mach kernel and FreeBSD libraries) is Unix.

Isn't this what the Open Group is taking Apple to court over?

> Linux on the other hand is, as RMS insists, and implementation of the GNU 
> System running on a Linux kernel, and as we all know GNU's Not Unix!

RMS as re-stated his mantra that it is GNU/Linux not just Linux for the
SCO/IBM war.  See
http://techupdate.zdnet.com/techupdate/stories/main/0,14179,2914132,00.html
While I don't disagree with the distinction between the OS (including the
kernel) and just the kernel I getting a little board of RMS.  While a lot
of software that ships under the various distributions is developed against
the GPL not all units are.  What about the Apache web server?  Shouldn't 
system that have Apache running be called "GNU/AFS/Linux"?

> On the other hand - if I address the older IT professionals on this list,
why 
> did you first get into Linux?  I'll bet for a lot of you it's because it 
> meant you could have Unix on your home machines and you could get your
hands 
> dirty in it.

Well for me this wasn't the reason.  It was performance pure and simple.  I
was
already running Solaris 2.5.1 (x86) so I already had Unix on my home PC.
Then
I was show how much fast Linux ran on the same hardware - I swapped.

If truth be told I did have Linux running before Solaris, but the kernel
didn't
support (then) some programming I wanted to play with.  When I got hold of
Solaris I could play with it.  In hind sight I wish I had taken the Linux
code
and added in the support for writable mmap(2) pages in userland - I'd be a
proper
Linux kernel hacker now.   On well "life" is a four letter word.

> So when is a Unix not a Unix - every third wednesday and on bank holidays,
as 
> near as I can tell.

And when there is a y in the month.

Steve