[ntp:questions] 4.2.8 can't find timepps.h or can it?

Harlan Stenn stenn at ntp.org
Sun Dec 21 21:39:06 UTC 2014

William Unruh writes:
> On 2014-12-21, Harlan Stenn <stenn at ntp.org> wrote:
> > It doesn't contradict itself.  It finds sys/timepps.h.  This is
> > expected.
> >
> > It does not find timepps.h.  This is expected.
> >
> > The former lives in /usr/include/sys/timepps.h, as you note above.
> >
> > The latter does not live in /usr/include/timepps.h, as you note above.
> >
> > We both note that ntpd compiles and the ATOM driver works.
> Why would it be searching for timepps.h when it had already found
> sys/timepps.h?

Using a general example, because it's much easier and safer to write and

 AC_CHECK_HEADERS([timepps.h sys/timepps.h])

than it is to unequiviocally decide that one of a choice is always
better than the other and then write code so that we *only* look for the
other one if the former doesn't exist.


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