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Diffstat (limited to 'src/lib/libc/stdlib/gcvt.c')
-rw-r--r-- | src/lib/libc/stdlib/gcvt.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/gcvt.c b/src/lib/libc/stdlib/gcvt.c new file mode 100644 index 0000000000..bc6295c03d --- /dev/null +++ b/src/lib/libc/stdlib/gcvt.c | |||
@@ -0,0 +1,108 @@ | |||
1 | /* $OpenBSD: gcvt.c,v 1.9 2006/01/10 16:18:37 millert Exp $ */ | ||
2 | |||
3 | /* | ||
4 | * Copyright (c) 2002, 2003, 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 <locale.h> | ||
24 | #include <stdio.h> | ||
25 | #include <stdlib.h> | ||
26 | #include <string.h> | ||
27 | |||
28 | extern char *__dtoa(double, int, int, int *, int *, char **); | ||
29 | |||
30 | char * | ||
31 | gcvt(double value, int ndigit, char *buf) | ||
32 | { | ||
33 | char *digits, *dst, *src; | ||
34 | int i, decpt, sign; | ||
35 | struct lconv *lconv; | ||
36 | |||
37 | lconv = localeconv(); | ||
38 | if (ndigit == 0) { | ||
39 | buf[0] = '\0'; | ||
40 | return (buf); | ||
41 | } | ||
42 | |||
43 | digits = __dtoa(value, 2, ndigit, &decpt, &sign, NULL); | ||
44 | if (decpt == 9999) { | ||
45 | /* | ||
46 | * Infinity or NaN, convert to inf or nan with sign. | ||
47 | * We assume the buffer is at least ndigit long. | ||
48 | */ | ||
49 | snprintf(buf, ndigit + 1, "%s%s", sign ? "-" : "", | ||
50 | *digits == 'I' ? "inf" : "nan"); | ||
51 | return (buf); | ||
52 | } | ||
53 | |||
54 | dst = buf; | ||
55 | if (sign) | ||
56 | *dst++ = '-'; | ||
57 | |||
58 | if (decpt < 0 || decpt > ndigit) { | ||
59 | /* exponential format (e.g. 1.2345e+13) */ | ||
60 | if (--decpt < 0) { | ||
61 | sign = 1; | ||
62 | decpt = -decpt; | ||
63 | } else | ||
64 | sign = 0; | ||
65 | src = digits; | ||
66 | *dst++ = *src++; | ||
67 | *dst++ = *lconv->decimal_point; | ||
68 | while (*src != '\0') | ||
69 | *dst++ = *src++; | ||
70 | *dst++ = 'e'; | ||
71 | if (sign) | ||
72 | *dst++ = '-'; | ||
73 | else | ||
74 | *dst++ = '+'; | ||
75 | if (decpt < 10) { | ||
76 | *dst++ = '0'; | ||
77 | *dst++ = '0' + decpt; | ||
78 | *dst = '\0'; | ||
79 | } else { | ||
80 | /* XXX - optimize */ | ||
81 | for (sign = decpt, i = 0; (sign /= 10) != 0; i++) | ||
82 | continue; | ||
83 | dst[i + 1] = '\0'; | ||
84 | while (decpt != 0) { | ||
85 | dst[i--] = '0' + decpt % 10; | ||
86 | decpt /= 10; | ||
87 | } | ||
88 | } | ||
89 | } else { | ||
90 | /* standard format */ | ||
91 | for (i = 0, src = digits; i < decpt; i++) { | ||
92 | if (*src != '\0') | ||
93 | *dst++ = *src++; | ||
94 | else | ||
95 | *dst++ = '0'; | ||
96 | } | ||
97 | if (*src != '\0') { | ||
98 | if (src == digits) | ||
99 | *dst++ = '0'; /* zero before decimal point */ | ||
100 | *dst++ = *lconv->decimal_point; | ||
101 | for (i = decpt; digits[i] != '\0'; i++) { | ||
102 | *dst++ = digits[i]; | ||
103 | } | ||
104 | } | ||
105 | *dst = '\0'; | ||
106 | } | ||
107 | return (buf); | ||
108 | } | ||