On Fri, 27 May 2022, Niall Douglas via Liaison wrote:

> From your comment would this be better?
>
> --- cut ---
> Opening a file with private mode (\code{'p'} as the last character in
> the mode argument) creates a file whose contents can not be accessed by
> other means at any point in time, but is as if created at
> \code{filename}. If the implementation is not capable of creating
> private files, it shall fail setting \code{errno} to \code{ENOTSUP}.
> --- cut ---

Yes, though that should be "cannot", and you'd need changes to the errno.h
specification to add ENOTSUP. Note that no other I/O errors have defined
errno values in ISO C, so it seems rather questionable to add one just for
this particular case.

-- 
Joseph S. Myers
joseph_at_[hidden]