?RCS: $Id: d_nolnbuf.U 1 2006-08-24 12:32:52Z rmanfredi $
?RCS:
?RCS: Copyright (c) 1991-1997, 2004-2006, 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 4.0.
?RCS:
?RCS: $Log: d_nolnbuf.U,v $
?RCS: Revision 3.0.1.1  1994/05/06  14:46:07  ram
?RCS: patch23: avoid looping in the "see that again?" prompt (WED)
?RCS:
?RCS: Revision 3.0  1993/08/18  12:06:43  ram
?RCS: Baseline for dist 3.0 netwide release.
?RCS:
?MAKE:d_nolnbuf: test +cc cat rm Setvar Myread
?MAKE:	-pick add $@ %<
?S:d_nolnbuf:
?S:	This variable conditionally defines the NOLINEBUF symbol, which
?S:	indicates to the C program that stdout is not buffered, so that
?S:	the program can call setbuf() or setlinebuf() for efficiency.
?S:.
?C:NOLINEBUF:
?C:	This symbol, if defined, indicates that stdout is not buffered, so that
?C:	the program can call setbuf() or setlinebuf() for efficiency.
?C:.
?H:#$d_nolnbuf	NOLINEBUF	/**/
?H:.
?T:xxx
?F:!blurfl
?LINT:set d_nolnbuf
: check for buffering of stdout
echo " "
case "$d_nolnbuf" in
'')
	$cat <<'EOT' >blurfl.c
#include <stdio.h>
int main()
{
	int i;

	for (i = 0; i < 5; i++) {
		putchar(i+'a');
		sleep(1);
	}
	putchar('\n');
}
EOT
	$cc -o blurfl blurfl.c >/dev/null 2>&1;
	$rm -f blurfl.c
	$cat >&4 <<'EOM'
Checking for buffering of stdout to terminal.

Observe the following characters as they are printed out, to see whether they
print out all at once, or with a 1 second pause between each of them.  If they
print out one by one, you don't have buffering.  If they print together (after
about a 5 second pause), you do have buffering.

EOM
	dflt='Type return to start printing the test characters'
	rp=''
	. ./myread
	xxx=y
	while $test "$xxx" = 'y'; do
		./blurfl 1>&4
		dflt=n
		rp='Would you like to see that again?'
		. ./myread
 		case "$ans" in
		[yY]*) xxx="y";;
		*) xxx="n";;
 		esac
	done
	dflt=y
	rp="Do you have buffering (printed all at once)?"
	. ./myread
	case "$ans" in
	n*) val="$define";;
	*)  val="$undef";;
	esac
	;;
*)
	case "$d_nolnbuf" in
	"$define") dflt=n;;
	*) dflt=y;;
	esac
	rp="Do you have buffering on stdout to terminals?"
	. ./myread
	case "$ans" in
	n*) val="$define";;
	*)  val="$undef";;
	esac
	;;
esac
set d_nolnbuf
eval $setvar

