?RCS: $Id: d_fd_set.U,v 3.0.1.3 1997/02/28 15:33:16 ram Exp $
?RCS:
?RCS: Copyright (c) 1991-1993, Raphael Manfredi
?RCS: 
?RCS: You may redistribute only under the terms of the Artistic Licence,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic Licence; a copy of which may be found at the root
?RCS: of the source tree for dist 3.0.
?RCS:
?RCS: $Log: d_fd_set.U,v $
?RCS: Revision 3.0.1.3  1997/02/28  15:33:16  ram
?RCS: patch61: added ?F: metalint hint
?RCS:
?RCS: Revision 3.0.1.2  1994/06/20  06:57:23  ram
?RCS: patch30: extended scope for fd_set checks (ADO)
?RCS:
?RCS: Revision 3.0.1.1  1994/01/24  14:06:27  ram
?RCS: patch16: comments for HAS_FD_* symbols were not consistent
?RCS:
?RCS: Revision 3.0  1993/08/18  12:06:02  ram
?RCS: Baseline for dist 3.0 netwide release.
?RCS:
?MAKE:d_fd_set d_fd_macros d_fds_bits: Compile cat rm Oldconfig \
	d_socket i_systime i_sysselct i_stdlib run
?MAKE:	-pick add $@ %<
?S:d_fd_set:
?S:	This variable contains the eventual value of the HAS_FD_SET symbol,
?S:	which indicates if your C compiler knows about the fd_set typedef.
?S:.
?S:d_fd_macros:
?S:	This variable contains the eventual value of the HAS_FD_MACROS symbol,
?S:	which indicates if your C compiler knows about the macros which
?S:	manipulate an fd_set.
?S:.
?S:d_fds_bits:
?S:	This variable contains the eventual value of the HAS_FDS_BITS symbol,
?S:	which indicates if your fd_set typedef contains the fds_bits member.
?S:	If you have an fd_set typedef, but the dweebs who installed it did
?S:	a half-fast job and neglected to provide the macros to manipulate
?S:	an fd_set, HAS_FDS_BITS will let us know how to fix the gaffe.
?S:.
?C:HAS_FD_SET:
?C:	This symbol, when defined, indicates presence of the fd_set typedef
?C:	in <sys/types.h>
?C:.
?C:HAS_FD_MACROS:
?C:	This symbol, when defined,  indicates presence of the macros used to
?C:	manipulate an fd_set.
?C:.
?C:HAS_FDS_BITS:
?C:	This symbol, when defined, indicates presence of the fds_bits member in
?C:	fd_set.  This knowledge is useful if fd_set is available but the macros
?C:	aren't.
?C:.
?H:#$d_fd_set HAS_FD_SET	/**/
?H:#$d_fd_macros HAS_FD_MACROS	/**/
?H:#$d_fds_bits HAS_FDS_BITS	/**/
?H:.
: check for fd_set items
$cat <<EOM

Checking to see how well your C compiler handles fd_set and friends ...
EOM
?X: The FD_SET macros can be in strange places.  On some SysV-based
?X: systems, they are in <sys/bsdtypes.h>, which is included (perhaps)
?X: by <sys/socket.h>.  We won't force people to include
?X: <sys/bsdtypes.h> because it might introduce other
?X: incompatibilities.
$cat >try.c <<EOCP
#$i_stdlib I_STDLIB
#ifdef I_STDLIB
#include <stdlib.h>
#endif
#$i_systime I_SYS_TIME
#$i_sysselct I_SYS_SELECT
#$d_socket HAS_SOCKET
#include <sys/types.h>
#ifdef HAS_SOCKET
#include <sys/socket.h> /* Might include <sys/bsdtypes.h> */
#endif
#ifdef I_SYS_TIME
#include <sys/time.h>
#endif
#ifdef I_SYS_SELECT
#include <sys/select.h>
#endif
int main() {
	fd_set fds;

#ifdef TRYBITS
	if(fds.fds_bits);
#endif

#if defined(FD_SET) && defined(FD_CLR) && defined(FD_ISSET) && defined(FD_ZERO)
	exit(0);
#else
	exit(1);
#endif
}
EOCP
set try -DTRYBITS
if eval $compile; then
	d_fds_bits="$define"
	d_fd_set="$define"
	echo "Well, your system knows about the normal fd_set typedef..." >&4
	if $run ./try; then
		echo "and you have the normal fd_set macros (just as I'd expect)." >&4
		d_fd_macros="$define"
	else
		$cat >&4 <<'EOM'
but not the normal fd_set macros!  Gaaack!  I'll have to cover for you.
EOM
		d_fd_macros="$undef"
	fi
else
	$cat <<'EOM'
Hmm, your compiler has some difficulty with fd_set.  Checking further...
EOM
	set try
	if eval $compile; then
		d_fds_bits="$undef"
		d_fd_set="$define"
		echo "Well, your system has some sort of fd_set available..." >&4
		if $run ./try; then
			echo "and you have the normal fd_set macros." >&4
			d_fd_macros="$define"
		else
			$cat <<'EOM'
but not the normal fd_set macros!  Gross!  More work for me...
EOM
			d_fd_macros="$undef"
		fi
	else
	echo "Well, you got zip.  That's OK, I can roll my own fd_set stuff." >&4
		d_fd_set="$undef"
		d_fds_bits="$undef"
		d_fd_macros="$undef"
	fi
fi
$rm -f try try.*