?RCS: $Id: d_gconvert.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: Original Author: Andy Dougherty <doughera@lafcol.lafayette.edu>
?RCS:
?RCS: $Log: d_gconvert.U,v $
?RCS: Revision 3.0.1.3  1997/02/28  15:33:38  ram
?RCS: patch61: integrated new unit from perl5
?RCS:
?RCS: Revision 3.0.1.2  1995/07/25  13:55:59  ram
?RCS: patch56: improved comments about the Gconvert macro (ADO)
?RCS: patch56: force compile-link test since it may exist but be unusable (ADO)
?RCS:
?RCS: Revision 3.0.1.1  1994/10/29  16:12:51  ram
?RCS: patch36: created by ADO
?RCS:
?MAKE:d_Gconvert: cat cc ccflags ldflags libs Inlibc rm _o
?MAKE:	-pick add $@ %<
?S:d_Gconvert:
?S:	This variable holds what Gconvert is defined as to convert
?S:	floating point numbers into strings. It could be 'gconvert'
?S:	or a more complex macro emulating gconvert with gcvt() or sprintf.
?S:.
?C:Gconvert:
?C:	This preprocessor macro is defined to convert a floating point
?C:	number to a string without a trailing decimal point.  This
?C:	emulates the behavior of sprintf("%g"), but is sometimes much more
?C:	efficient.  If gconvert() is not available, but gcvt() drops the
?C:	trailing decimal point, then gcvt() is used.  If all else fails,
?C:	a macro using sprintf("%g") is used. Arguments for the Gconvert
?C:	macro are: value, number of digits, whether trailing zeros should
?C:	be retained, and the output buffer.
?C:	Possible values are:
?C:		d_Gconvert='gconvert((x),(n),(t),(b))'
?C:		d_Gconvert='gcvt((x),(n),(b))'
?C:		d_Gconvert='sprintf((b),"%.*g",(n),(x))'
?C:	The last two assume trailing zeros should not be kept.
?C:.
?H:#define Gconvert(x,n,t,b) $d_Gconvert
?H:.
?T: xxx_list xxx_convert
?F:!try
?X: 
: Check how to convert floats to strings.
echo " "
echo "Checking for an efficient way to convert floats to strings."
?X: We want to be sure to drop trailing decimal points (perl5
?X: needs this).
$cat >try.c <<'EOP'
#ifdef TRY_gconvert
#define Gconvert(x,n,t,b) gconvert((x),(n),(t),(b))
char *myname = "gconvert";
#endif
#ifdef TRY_gcvt
#define Gconvert(x,n,t,b) gcvt((x),(n),(b))
char *myname = "gcvt";
#endif
#ifdef TRY_sprintf
#define Gconvert(x,n,t,b) sprintf((b),"%.*g",(n),(x))
char *myname = "sprintf";
#endif

#include <stdio.h>

int
checkit(expect, got)
char *expect;
char *got;
{
    if (strcmp(expect, got)) {
		printf("%s oddity:  Expected %s, got %s\n",
			myname, expect, got);
		exit(1);
	}
}

int
int main()
{ 
	char buf[64]; 
	buf[63] = '\0';

	/* This must be 1st test on (which?) platform */
	/* Alan Burlison <AlanBurlsin@unn.unisys.com> */
	Gconvert(0.1, 8, 0, buf);
	checkit("0.1", buf);

	Gconvert(1.0, 8, 0, buf); 
	checkit("1", buf);

	Gconvert(0.0, 8, 0, buf); 
	checkit("0", buf);

	Gconvert(-1.0, 8, 0, buf); 
	checkit("-1", buf);

	/* Some Linux gcvt's give 1.e+5 here. */
	Gconvert(100000.0, 8, 0, buf); 
	checkit("100000", buf);
	
	/* Some Linux gcvt's give -1.e+5 here. */
	Gconvert(-100000.0, 8, 0, buf); 
	checkit("-100000", buf);

	exit(0);
}
EOP
?X: List of order in which to search for functions.
?X: Usual order of efficiency is gconvert gcvt sprintf
?X: Respect a previous or hinted value.
case "$d_Gconvert" in
gconvert*) xxx_list='gconvert gcvt sprintf' ;;
gcvt*) xxx_list='gcvt gconvert sprintf' ;;
sprintf*) xxx_list='sprintf gconvert gcvt' ;;
*) xxx_list='gconvert gcvt sprintf' ;;
esac

for xxx_convert in $xxx_list; do
	echo "Trying $xxx_convert"
	$rm -f try try$_o
	if $cc $ccflags -DTRY_$xxx_convert $ldflags -o try \
		try.c $libs > /dev/null 2>&1 ; then
		echo "$xxx_convert" found. >&4
		if ./try; then
			echo "I'll use $xxx_convert to convert floats into a string." >&4
			break;
		else
			echo "...But $xxx_convert didn't work as I expected."
		fi
	else
		echo "$xxx_convert NOT found." >&4
	fi
done
		
case "$xxx_convert" in
gconvert) d_Gconvert='gconvert((x),(n),(t),(b))' ;;
gcvt) d_Gconvert='gcvt((x),(n),(b))' ;;
*) d_Gconvert='sprintf((b),"%.*g",(n),(x))' ;;
esac