Re: snprintf()

On Fri, Feb/ 2/07 10:52:28PM -0500, Tom Lane wrote:
> Kate F <kate(at)cats(dot)meow(dot)at> writes:
> > ... does PostgreSQL replace my system's snprintf() prototype with
> > its own implementation's?
>
> We do on some platforms where configure decides the system version
> is deficient ... I don't recall the exact conditions at the moment.
> I wouldn't really have expected that to happen on any *BSD, but you
> could look into the generated Makefile.global to find out.

I don't see anything that looks relevant for my Makefile.global; I
would be surprised if NetBSD's were overridden too!

> > For reference, the relevant part of C99:
> > 7.19.6.5 2 If n is zero, nothing is written, and s may be a null
> > pointer.
>
> For reference, the relevant part of the Single Unix Spec:
>
> If the value of n is zero on a call to snprintf(), an
> unspecified value less than 1 is returned.

Aha! I do recall either POSIX or SUS defers to C on conflicts... I
can't find which, though. If this snprintf() is following SUS
behaviour, that's fine. Thank you!

> So the behavior you'd like to depend on is unportable anyway, and
> that coding will get rejected if submitted as a Postgres patch.

Absolutley (and I assume you target C89, too, which does not provide
snprintf()). This was just something personal where I happened to use
it for convenience.

Thank you for checking that - and appologies for posting to the wrong
list; that should have been to -bugs!

Regards,

--
Kate