[Info-vax] What is a "real" Unix ?

[Simon Clubley]

On 2023-09-02, Bob Eager <news0009 at eager.cx> wrote:
> On Sat, 02 Sep 2023 23:07:24 +0200, Johnny Billquist wrote:
>
>> On 2023-09-01 14:50, candycane wrote:
>>>   SC> Yes, at least on Linux.
>>> 
>>>   SC> The dd on other operating systems may use a different signal.
>>> 
>>> Is dd on non unix systems?
>> 
>> Yes. Linux for example. Linux is not Unix, but it certainly tries to
>> work the same.
>
> "Jumped uo UNIX wannabe"

In that case, what is a "real" Unix ?

Is it something that implements a set of user-visible APIs and certain
behaviour within its kernel (fork() semantics for example) ?

Is it something that came from a specific source code base and hence
nothing else can never be called Unix no matter how compatible that other
something is ?

If BSD is a Unix, then is System V also a Unix ?

If System V is a Unix, then why can't something else that also implements
the same APIs and kernel behaviour also be a Unix ?

Or is Linux really a Unix after all (in every way that matters) and what's
really going on here is just some out-of-touch BSD Unix elitism ?

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.