[TUHS] MacOS X is Unix (tm)

Chet Ramey chet.ramey at case.edu
Tue Jan 3 03:53:57 AEST 2017

On 1/2/17 12:32 PM, Larry McVoy wrote:
> On Mon, Jan 02, 2017 at 12:05:15PM -0500, Chet Ramey wrote:
>> On 1/2/17 11:49 AM, Larry McVoy wrote:
>>> On Mon, Jan 02, 2017 at 11:44:06AM -0500, Chet Ramey wrote:
>>>> On 1/2/17 6:31 AM, Joerg Schilling wrote:
>>>>> David <david at kdbarto.org> wrote:
>>>>>> MacOS X is a certified Unix (tm) OS. Not Unix-Like.
>>>>> Given that MacOS X is not POSIX compliant, I would call it a UNIX-alike.
>>>>> Note that passing the certification tests unfortunately does not grant 
>>>>> POSIX compliance :-(
>>>> That's pretty much exactly what it means.  You have either found a bug or a
>>>> place where the interpretation is disputed.
>>> Joerg is pretty smart, he's been around the block.  There have been
>>> multiple POSIX standards, just like there is C9, C11, etc.  My guess is
>>> MacOS got certified for an earlier standard and hasn't kept up.

I totally agree that this happened.  Apple ships bash-3.2 as their shell,
and there is a combination of bug fixes and subsequent interpretations
that renders it non-conformant to the Posix of today.  Lots of things
change in 14 years.  My objection was that the original statement lacked

> Anyhoo, if the POSIX test suite now is anything like the one back then
> (late 1980's), it's a steaming pile of shit.  It was absolutely trivial to
> pass that test and have all sorts of stuff that wasn't POSIX compliant.

I find this very easy to believe.  I ran bash through several versions of
the 1003.2 -- back then -- conformance test, and the earliest ones (early
to mid 90s) were obviously written to ensure that ksh passed.  Just chock
full of constructs and builtins that were ksh-specific.  Most of that
stuff got cleaned up eventually, but the first versions were clearly the
product of someone who was not familiar with Posix or historical versions
of sh at all.

The worst part was the multiple subsequent discussions on the austin-group
list that ended up with some resolution like "yes, I know this is what the
text of the standard says, but this is what we really meant."  Definitely
a moving target.

> As a further aside, this was one of the best years in my life.  I was
> young and fit, 

Weren't we all.

``The lyf so short, the craft so long to lerne.'' - Chaucer
		 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet at case.edu    http://cnswww.cns.cwru.edu/~chet/

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