Dear All,
I was wondering.
I have been using linux and freebsd for some time.. But one question
disturbs me: there are constant notes about POSIX saying that this and
that comply to posix, the other things don't etc.
But when I tried to actually see what POSIX consists of I found that
it is not publicly available.
I ask then: what is the sense of this? What is the sense of a standard
that no one can know? And what can the contributors to all those free
oerating systems (GNU and BSD) do to comply to these standards if they
don't even know them....

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CaveSnow <cavesnow@gmail.com> wrote:
> I was wondering.
> I have been using linux and freebsd for some time.. But one question
> disturbs me: there are constant notes about POSIX saying that this and
> that comply to posix, the other things don't etc.
> But when I tried to actually see what POSIX consists of I found that
> it is not publicly available.
> I ask then: what is the sense of this? What is the sense of a standard
> that no one can know? And what can the contributors to all those free
> oerating systems (GNU and BSD) do to comply to these standards if they
> don't even know them....

The current incarnation of POSIX is the Single Unix Specification,
Version 3. You can read and download it for free from

http://www.unix.org/online.html

The only thing they ask for is a registration (but there are also
seem to be ways to get around that) and it looks very much as if
the registration is just for statisical purposes.

Regards, Jens
--
\   Jens Thoms Toerring  ___      jt@toerring.de
\__________________________      http://toerring.de

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On Jul 15, 1:32 pm, j...@toerring.de (Jens Thoms Toerring) wrote:
> CaveSnow <caves...@gmail.com> wrote: 
>
> The current incarnation of POSIX is the Single Unix Specification,
> Version 3. You can read and download it for free from
>
> http://www.unix.org/online.html
>
> The only thing they ask for is a registration (but there are also
> seem to be ways to get around that) and it looks very much as if
> the registration is just for statisical purposes.
>
>                                 Regards, Jens
> --
>   \   Jens Thoms Toerring  ___      j...@toerring.de
>    \__________________________      http://toerring.de

Ok, got it. I'm a bit a noob so I hope you don't mind if I ask you
what do you mean by "The current incarnation of POSIX is the Single
Unix Specification"... I thought that these two things were rather
different. And if now one should refer to Single Unix Specification
where has the original POSIX gone. Is it now out of date and has it
been inherited by the Single Unix Specification? You see I do not know
much about the subject, so could you tell me(or post some links like
the one above, that was rather helpful) something about the evolution
of these standards and which one a programmer should comply to?
Thanks.

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CaveSnow <cavesnow@gmail.com> wrote:
> Ok, got it. I'm a bit a noob so I hope you don't mind if I ask you
> what do you mean by "The current incarnation of POSIX is the Single
> Unix Specification"... I thought that these two things were rather
> different. And if now one should refer to Single Unix Specification
> where has the original POSIX gone.

I am also not an expert on the evolution of POSIX/SUV but as far
as I know in the beginning there was POSIX, wich was extremely
expensive. An alternative to POSIX was developed in the early
1990, the Common API Specification, which was free and thus be-
came rather popular. Then, in 1998, the "Austin Group" was set
up, which developed a combined standard, which is the Single
UNIX specification, now in version 3. And the latest version
of the POSIX.1 standard is IEEE Std 1003.1, 2004 Edition, i.e.
SUV3. For more details see e.g.

http://www.opengroup.org/austin/papers/posix_faq.html

Regards, Jens
--
\   Jens Thoms Toerring  ___      jt@toerring.de
\__________________________      http://toerring.de

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CaveSnow <cavesnow@gmail.com> writes:
>I have been using linux and freebsd for some time.. But one question
>disturbs me: there are constant notes about POSIX saying that this and
>that comply to posix, the other things don't etc.
>But when I tried to actually see what POSIX consists of I found that
>it is not publicly available.
>I ask then: what is the sense of this? What is the sense of a standard
>that no one can know? And what can the contributors to all those free
>oerating systems (GNU and BSD) do to comply to these standards if they
>don't even know them....

Its publicly available... You just have to pay for it.

This is pretty true for just about any standards body work. Ie. the
ITU, other IEEE work, even the NEC (national electric code) are
available, for a fee. The fees support the standards body to make the
standard in the first place.

Ie. POSIX as you would probably want, is available from shop.ieee.org.
The 1003.1 2004 EDITION IEEE Standard for Information Technology --
Portable Operating System Interface is available for $240 for PDF download.
(nobody's going to be printing 3760 pages to ship dead trees anywhere).

Even getting something certified by IEEE as POSIX isn't all that bad,
around $5k to start, and $2k to renew, but thats something a handful of
developers aren't going to be able to raise, but a company or foundation
should be able to.

But, the core of what POSIX is now is the Single Unix Specification,
produced by what is now The Open Group. They don't charge for access
to the SUS.

The two groups started seperately, but decided to merge their work
together quite some time ago, so the core of POSIX is the SUS, but
you'd still have to through the IEEE to certify something POSIX (tm).

The Opengroup's history page is probably better than others I've seen
out there.

http://opengroup.org/austin/papers/single_unix_faq.html

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Jens Thoms Toerring wrote:

> I am also not an expert on the evolution of POSIX/SUV but as far
> as I know in the beginning there was POSIX, wich was extremely
> expensive. An alternative to POSIX was developed in the early
> 1990, the Common API Specification, which was free and thus be-
> came rather popular.

Not even close.

The X/Open specifications that became SUS were around before POSIX.
They were originally called the "X/Open Portability Guide" (XPG).
XPG1 and XPG2 were based mostly on System V.  XPG3 was modified to
align with the original POSIX.1 (i.e. it was a superset of
POSIX.1-1988).  XPG4 was further modified to align with the ISO C
Standard, POSIX.1-1990 and POSIX.2-1992.  Then when the UNIX
trademark was donated to X/Open by Novell, a bunch of extra
interfaces were added to XPG4 to turn it into the Single UNIX
Specification, version 1 (SUSv1).

Up until this point all of these specifications and standards
(from IEEE/ISO or X/Open) were only available on paper, and were
expensive.

Next, realtime and threads interfaces were added to POSIX.1, and
the revised POSIX.1-1996 was incorporated into SUSv2 (along with
ISO C Amendment 1 and large file support).  The definitive SUSv2
was the paper version, but an HTML version was also produced and
made freely available on The Open Group's website.

> Then, in 1998, the "Austin Group" was set up, ...

That part you got right.

--
Geoff Clare <netnews@gclare.org.uk>

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Geoff Clare <geoff@clare.see-my-signature.invalid> wrote:
> Jens Thoms Toerring wrote:
 
[vbcol=seagreen]
> Not even close.

> The X/Open specifications that became SUS were around before POSIX.
> They were originally called the "X/Open Portability Guide" (XPG).
> XPG1 and XPG2 were based mostly on System V.  XPG3 was modified to
> align with the original POSIX.1 (i.e. it was a superset of
> POSIX.1-1988).  XPG4 was further modified to align with the ISO C
> Standard, POSIX.1-1990 and POSIX.2-1992.  Then when the UNIX
> trademark was donated to X/Open by Novell, a bunch of extra
> interfaces were added to XPG4 to turn it into the Single UNIX
> Specification, version 1 (SUSv1).

> Up until this point all of these specifications and standards
> (from IEEE/ISO or X/Open) were only available on paper, and were
> expensive.

> Next, realtime and threads interfaces were added to POSIX.1, and
> the revised POSIX.1-1996 was incorporated into SUSv2 (along with
> ISO C Amendment 1 and large file support).  The definitive SUSv2
> was the paper version, but an HTML version was also produced and
> made freely available on The Open Group's website.

Thanks for the correction - as I said I am definitely no expert
on the somewhat convoluted history of the different standards;-)

Regards, Jens
--
\   Jens Thoms Toerring  ___      jt@toerring.de
\__________________________      http://toerring.de

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