+
−/*
+
− * Embedded [v]sprintf() implementation by Michael Spacefalcon,
+
− * loosely based on the 4.3BSD-Tahoe version.
+
− *
+
− * This module contains the floating point conversion functions.
+
− */
+
−
+
−#include <sys/types.h>
+
−#include <ctype.h>
+
−#include "defs.h"
+
−
+
−extern double modf();
+
−
+
−extern u_char * _sprintf_field(u_char *op, int width, int flags, int sign,
+
−			u_char *body, int size, int dprec, int fpprec);
+
−
+
−#define	MAX_INT_DIGITS	10	/* 2^32-1 in decimal */
+
−#define	MAXFRACT	16	/* max sensible for 64-bit double */
+
−#define	DEFPREC		6
+
−
+
−static char *
+
−emit_integer_portion(unsigned number, char *endp)
+
−{
+
−	char *t = endp;
+
−
+
−	do {
+
−		*--t = tochar(number % 10);
+
−		number /= 10;
+
−	} while (number);
+
−	return (t);
+
−}
+
−
+
−static int
+
−f_round(double fract, char *start, char *end, int sign)
+
−{
+
−	double tmp;
+
−
+
−	(void)modf(fract * 10, &tmp);
+
−	if (tmp > 4)
+
−		for (;; --end) {
+
−			if (*end == '.')
+
−				--end;
+
−			if (++*end <= '9')
+
−				break;
+
−			*end = '0';
+
−		}
+
−	/* ``"%.3f", (double)-0.0004'' gives you a negative 0. */
+
−	else if (sign == '-')
+
−		for (;; --end) {
+
−			if (*end == '.')
+
−				--end;
+
−			if (*end != '0')
+
−				break;
+
−			if (end == start)
+
−				return(1);	/* clear the -ve */
+
−		}
+
−	return(0);
+
−}
+
−
+
−u_char *
+
−_sprintf_percent_f(u_char *op, int width, int flags, int sign,
+
−		double number, int prec)
+
−{
+
−	char buf[MAX_INT_DIGITS + 1 + MAXFRACT];
+
−	int extra_prec = 0;
+
−	int origsign = sign;
+
−	double fract, tmp;
+
−	char *start, *t;
+
−
+
−	/* first order of business: weed out infinities and NaNs */
+
−	if (isinf(number)) {
+
−		if (number < 0)
+
−			sign = '-';
+
−		return _sprintf_field(op, width, flags, sign, "Inf", 3, 0, 0);
+
−	}
+
−	if (isnan(number))
+
−		return _sprintf_field(op, width, flags, sign, "NaN", 3, 0, 0);
+
−	/* OK, we know it's a valid real like in the good old VAX days */
+
−	if (number < 0) {
+
−		sign = '-';
+
−		number = -number;
+
−	}
+
−	fract = modf(number, &tmp);
+
−	if (tmp > (double) 0xFFFFFFFF)
+
−		return _sprintf_field(op, width, flags, sign, "Toobig", 6,
+
−					0, 0);
+
−	start = emit_integer_portion((unsigned) tmp, buf + MAX_INT_DIGITS);
+
−	if (prec > MAXFRACT) {
+
−		extra_prec = prec - MAXFRACT;
+
−		prec = MAXFRACT;
+
−	} else if (prec == -1)
+
−		prec = DEFPREC;
+
−	t = buf + MAX_INT_DIGITS;
+
−	/*
+
−	 * if precision required or alternate flag set, add in a
+
−	 * decimal point.
+
−	 */
+
−	if (prec || flags&ALT)
+
−		*t++ = '.';
+
−	/* if requires more precision and some fraction left */
+
−	if (fract) {
+
−		if (prec)
+
−			do {
+
−				fract = modf(fract * 10, &tmp);
+
−				*t++ = tochar((int)tmp);
+
−			} while (--prec && fract);
+
−		if (fract && f_round(fract, start, t - 1, sign))
+
−			sign = origsign;
+
−	}
+
−	return _sprintf_field(op, width, flags, sign, start, t - start,
+
−				0, prec + extra_prec);
+
−}