16636 want ptsname_r

16636 want ptsname_r

[Robert Mustacchi]

https://code.illumos.org/c/illumos-gate/+/3571

This adds a new POSIX-specified re-entrant version of ptsname().

Robert

Re: [developer] 16636 want ptsname_r

[Yuri Pankov]

Robert Mustacchi wrote:
> https://code.illumos.org/c/illumos-gate/+/3571
> 
> This adds a new POSIX-specified re-entrant version of ptsname().

Hi Robert,

Is there any published document for this (a draft?)?  All I could find
is documentation in FreeBSD and Linux where "non-standard" ptsname_r()
is setting errno in addition to returning non-0 value, and that doesn't
seem to match what's in review, so the standard has probably changed that?

Re: [developer] 16636 want ptsname_r

[Robert Mustacchi]

On 7/3/24 21:22, Yuri Pankov wrote:
> Robert Mustacchi wrote:
>> https://code.illumos.org/c/illumos-gate/+/3571
>>
>> This adds a new POSIX-specified re-entrant version of ptsname().
> 
> Hi Robert,
> 
> Is there any published document for this (a draft?)?  All I could find
> is documentation in FreeBSD and Linux where "non-standard" ptsname_r()
> is setting errno in addition to returning non-0 value, and that doesn't
> seem to match what's in review, so the standard has probably changed that?

Yes, POSIX 2024 was published. I didn't want to work off a non-draft.
The web form of it seems to not have been updated by the open group yet,
but the spec is available at
https://ieeexplore.ieee.org/document/10555529, but not for free
unfortunately. There are versions of what led to it at
https://austingroupbugs.net/view.php?id=508.

I have a "If successful, the ptsname_r( ) function shall return zero.
Otherwise, an error number shall be returned to indicate the error."
with the rationale being "Historically, some versions of ptsname( ) did
not set errno even when returning a null pointer. However, ptsname_r( )
is required to either populate the buffer with a valid name or return an
error value."

Spot checking the manual page I have for ptsname_r() in Ubuntu 22.04,
this matches. Same with musl. The FreeBSD manual page is different, but
notes it's changing for POSIX compat. Does that help at all?

Robert

Re: [developer] 16636 want ptsname_r

[Alan Coopersmith]

On 7/4/24 06:46, Robert Mustacchi wrote:
> Yes, POSIX 2024 was published. I didn't want to work off a non-draft.
> The web form of it seems to not have been updated by the open group yet,

They've said they're working on the web release, and hope to have it done in
"a few more weeks".  A couple of recent bugs in their tracker have been
corrections they found while working on the web publication:

https://www.mail-archive.com/austin-group-l@opengroup.org/msg12711.html
https://www.mail-archive.com/austin-group-l@opengroup.org/msg12725.html
https://www.mail-archive.com/austin-group-l@opengroup.org/msg12727.html

	-alan-