1/*	$OpenBSD: ecvt.c,v 1.7 2009/10/16 12:15:03 martynas Exp $	*/
2
3/*
4 * Copyright (c) 2002, 2006 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 *
18 * Sponsored in part by the Defense Advanced Research Projects
19 * Agency (DARPA) and Air Force Research Laboratory, Air Force
20 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
21 */
22
23#include <sys/cdefs.h>
24#include <stdio.h>
25#include <stdlib.h>
26#include <string.h>
27
28extern char *__dtoa(double, int, int, int *, int *, char **);
29extern void  __freedtoa(char *);
30static char *__cvt(double, int, int *, int *, int, int);
31
32static char *
33__cvt(double value, int ndigit, int * __restrict decpt, int * __restrict sign, int fmode, int pad)
34{
35	static char *s;
36	char *p, *rve, c;
37	size_t siz;
38
39	if (ndigit == 0) {
40		*sign = value < 0.0;
41		*decpt = 0;
42		return ("");
43	}
44
45	if (s) {
46		free(s);
47		s = NULL;
48	}
49
50	if (ndigit < 0)
51		siz = -ndigit + 1;
52	else
53		siz = ndigit + 1;
54
55
56	/* __dtoa() doesn't allocate space for 0 so we do it by hand */
57	if (value == 0.0) {
58		*decpt = 1 - fmode;	/* 1 for 'e', 0 for 'f' */
59		*sign = 0;
60		if ((rve = s = (char *)malloc(siz)) == NULL)
61			return(NULL);
62		*rve++ = '0';
63		*rve = '\0';
64	} else {
65		p = __dtoa(value, fmode + 2, ndigit, decpt, sign, &rve);
66		if (p == NULL)
67			return (NULL);
68		if (*decpt == 9999) {
69			/* Infinity or Nan, convert to inf or nan like printf */
70			*decpt = 0;
71			c = *p;
72			__freedtoa(p);
73			return(c == 'I' ? "inf" : "nan");
74		}
75		/* Make a local copy and adjust rve to be in terms of s */
76		if (pad && fmode)
77			siz += *decpt;
78		if ((s = (char *)malloc(siz)) == NULL) {
79			__freedtoa(p);
80			return(NULL);
81		}
82		(void) strlcpy(s, p, siz);
83		rve = s + (rve - p);
84		__freedtoa(p);
85	}
86
87	/* Add trailing zeros */
88	if (pad) {
89		siz -= rve - s;
90		while (--siz)
91			*rve++ = '0';
92		*rve = '\0';
93	}
94
95	return(s);
96}
97
98char *
99ecvt(double value, int ndigit, int * __restrict decpt, int * __restrict sign)
100{
101	return(__cvt(value, ndigit, decpt, sign, 0, 1));
102}
103
104char *
105fcvt(double value, int ndigit, int * __restrict decpt, int * __restrict sign)
106{
107	return(__cvt(value, ndigit, decpt, sign, 1, 1));
108}
109