?RCS: $Id: d_gconvert.U,v 3.0.1.3 1997/02/28 15:33:38 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: 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).
$cat >try.c <<'EOP'
#ifdef TRY_gconvert
#define Gconvert(x,n,t,b) gconvert((x),(n),(t),(b))
char *myname = "gconvert";
#endif
#ifdef TRY_gcvt
#define Gconvert(x,n,t,b) gcvt((x),(n),(b))
char *myname = "gcvt";
#endif
#ifdef TRY_sprintf
#define Gconvert(x,n,t,b) sprintf((b),"%.*g",(n),(x))
char *myname = "sprintf";
#endif
#include <stdio.h>
int
checkit(expect, got)
char *expect;
char *got;
{
if (strcmp(expect, got)) {
printf("%s oddity: Expected %s, got %s\n",
myname, expect, got);
exit(1);
}
}
int
main()
{
char buf[64];
buf[63] = '\0';
/* This must be 1st test on (which?) platform */
/* Alan Burlison <AlanBurlsin@unn.unisys.com> */
Gconvert(0.1, 8, 0, buf);
checkit("0.1", buf);
Gconvert(1.0, 8, 0, buf);
checkit("1", buf);
Gconvert(0.0, 8, 0, buf);
checkit("0", buf);
Gconvert(-1.0, 8, 0, buf);
checkit("-1", buf);
/* Some Linux gcvt's give 1.e+5 here. */
Gconvert(100000.0, 8, 0, buf);
checkit("100000", buf);
/* Some Linux gcvt's give -1.e+5 here. */
Gconvert(-100000.0, 8, 0, buf);
checkit("-100000", buf);
exit(0);
}
EOP
?X: List of order in which to search for functions.
?X: Usual order of efficiency is gconvert gcvt sprintf
?X: Respect a previous or hinted value.
case "$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