Re: Cross-platform availability of header files

[Ralf Corsepius]

On 03/15/2013 09:13 PM, Zack Weinberg wrote:
> On 2013-03-15 8:57 AM, Ralf Corsepius wrote:
> > aio.h and sys/mman.h are not available everywhere
>
> aio.h certainly, but are you aware of a *specific Unix-like system*
> which is in current use and does not provide <sys/mman.h>?
Unix-like! Not all OSes are Unix-like.

Most prominent one without mman.h is mingw. Others, I am aware about are 
certain newlib based toolchains.

Newlib also is one of the places which has a history of struggling with 
the _POSIX_*-defines (Also affects Cygwin).

> That header
> is mandatory in POSIX-2008 (although not before then) and the last time
> I can remember encountering a workstation-scale Unix environment that
> didn't have it was in the mid-nineties sometime.  I'd believe there
> might be embedded mostly-POSIX-compliant environments still that don't
> do virtual memory, but I've never seen one.
Correct - RTEMS is one of these. We have a rudimentary implementation of 
aio.h since 2010 and don't have mmap.h at all.

Ralf