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Re: FYI: POSIX update - SIGWINCH and 'struct winsize' (etc) to be added

On 22.10.2017 06:22, Robert Elz wrote:
>     Date:        Sun, 22 Oct 2017 05:59:41 +0200
>     From:        Kamil Rytarowski <>
>     Message-ID:  <>
>   | As far as I can tell, if something defines a namespace like
>   | _POSIX_SOURCE, it excludes _NETBSD_SOURCE. I've not researched the
>   | source of this mechanism, but this is my observation and common in 3rd
>   | party software.
> Excludes by default, yes, it is from sys/featuretest.h (which is included
> by just about every other standard header file.)
> #if !defined(_ANSI_SOURCE) && !defined(_POSIX_C_SOURCE) && \
>     !defined(_XOPEN_SOURCE) && !defined(_NETBSD_SOURCE)
> #define _NETBSD_SOURCE 1
> #endif
> That's where the _NETBSD_SOURCE definition normally comes from.
> I'm not sure that case is important for the current issue though, as if
> something is specifically defining _POSIX_SOURCE (or one of the other 2)
> then it certainly should not be using ioctl() and if there are such
> applications, and we break them, well, good...
> kre

What UNIX-like systems skip ioctl(2)s except plan9 (assuming that it is
UNIX-like)? We have a reversed logic compared to GNU. In GLIBC
additional namespace definitions include additional features instead of
hiding existing ones.

I think that 1 vnode optimization is a nanooptimization. I recall about
it somewhere, that in the past this was a bottle-neck.. but it was like
30-40 years ago. I'm personally for adding a new header.

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