1 /* $OpenBSD: ecvt.c,v 1.11 2019/01/25 00:19:25 millert Exp $ */
2
3 /*
4 * Copyright (c) 2002, 2006 Todd C. Miller <millert@openbsd.org>
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 <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include "gdtoa.h"
27
28 static char *__cvt(double, int, int *, int *, int, int);
29
30 static char *
__cvt(double value,int ndigit,int * decpt,int * sign,int fmode,int pad)31 __cvt(double value, int ndigit, int *decpt, int *sign, int fmode, int pad)
32 {
33 static char *s;
34 char *p, *rve, c;
35 size_t siz;
36
37 if (ndigit == 0) {
38 *sign = value < 0.0;
39 *decpt = 0;
40 return ("");
41 }
42
43 free(s);
44 s = NULL;
45
46 if (ndigit < 0)
47 siz = -ndigit + 1;
48 else
49 siz = ndigit + 1;
50
51
52 /* __dtoa() doesn't allocate space for 0 so we do it by hand */
53 if (value == 0.0) {
54 *decpt = 1 - fmode; /* 1 for 'e', 0 for 'f' */
55 *sign = 0;
56 if ((rve = s = malloc(siz)) == NULL)
57 return(NULL);
58 *rve++ = '0';
59 *rve = '\0';
60 } else {
61 p = __dtoa(value, fmode + 2, ndigit, decpt, sign, &rve);
62 if (p == NULL)
63 return (NULL);
64 if (*decpt == 9999) {
65 /* Infinity or Nan, convert to inf or nan like printf */
66 *decpt = 0;
67 c = *p;
68 __freedtoa(p);
69 return(c == 'I' ? "inf" : "nan");
70 }
71 /* Make a local copy and adjust rve to be in terms of s */
72 if (pad && fmode)
73 siz += *decpt;
74 if ((s = malloc(siz)) == NULL) {
75 __freedtoa(p);
76 return(NULL);
77 }
78 (void) strlcpy(s, p, siz);
79 rve = s + (rve - p);
80 __freedtoa(p);
81 }
82
83 /* Add trailing zeros */
84 if (pad) {
85 siz -= rve - s;
86 while (--siz)
87 *rve++ = '0';
88 *rve = '\0';
89 }
90
91 return(s);
92 }
93
94 char *
ecvt(double value,int ndigit,int * decpt,int * sign)95 ecvt(double value, int ndigit, int *decpt, int *sign)
96 {
97 return(__cvt(value, ndigit, decpt, sign, 0, 1));
98 }
99
100 char *
fcvt(double value,int ndigit,int * decpt,int * sign)101 fcvt(double value, int ndigit, int *decpt, int *sign)
102 {
103 return(__cvt(value, ndigit, decpt, sign, 1, 1));
104 }
105