RE: Writing Rules

[Dan Kegel]

Kevin Ryde wrote:

>    if grep "IP Filter: v3\.4\." /usr/include/netinet/ipl.h >/dev/null;
>then
>      AC_DEFINE(IPF_4_3, 1, [Define for IP Filter v3.4.x])
>    fi
>
> (Though whether it's particularly robust to be grepping particular
> include files is another matter.)

You can't assume the include files are in /usr/include.  Best to use
the proper macro for this, namely AC_EGREP_HEADER or AC_EGREP_CPP.  See

http://www.gnu.org/manual/autoconf-2.52/html_node/autoconf_67.html

e.g.
  AC_EGREP_HEADER("IP Filter: v3\.4\.", netinet/ipl.h, AC_DEFINE(IPF_4_3, 1,
[Define for IP Filter v3.4.x]))
or something like that.  (Untested, sorry.)

This matters a lot to me because I want every package to be
cross-compile-friendly...
- Dan