diff options
Diffstat (limited to 'src/lib/libc/stdlib/gcvt.c')
-rw-r--r-- | src/lib/libc/stdlib/gcvt.c | 99 |
1 files changed, 99 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..9fd664b346 --- /dev/null +++ b/src/lib/libc/stdlib/gcvt.c | |||
@@ -0,0 +1,99 @@ | |||
1 | /* $OpenBSD: gcvt.c,v 1.5 2003/06/17 21:56:24 millert Exp $ */ | ||
2 | |||
3 | /* | ||
4 | * Copyright (c) 2002, 2003 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 | #if defined(LIBC_SCCS) && !defined(lint) | ||
24 | static char rcsid[] = "$OpenBSD: gcvt.c,v 1.5 2003/06/17 21:56:24 millert Exp $"; | ||
25 | #endif /* LIBC_SCCS and not lint */ | ||
26 | |||
27 | #include <stdio.h> | ||
28 | #include <stdlib.h> | ||
29 | #include <string.h> | ||
30 | |||
31 | extern char *__dtoa(double, int, int, int *, int *, char **); | ||
32 | |||
33 | char * | ||
34 | gcvt(double value, int ndigit, char *buf) | ||
35 | { | ||
36 | char *digits, *dst, *src; | ||
37 | int i, decpt, sign; | ||
38 | |||
39 | if (ndigit == 0) { | ||
40 | buf[0] = '\0'; | ||
41 | return (buf); | ||
42 | } | ||
43 | |||
44 | digits = __dtoa(value, 2, ndigit, &decpt, &sign, NULL); | ||
45 | if (decpt == 9999) { | ||
46 | /* Infinity or NaN, assume buffer is at least ndigit long. */ | ||
47 | strlcpy(buf, digits, ndigit + 1); | ||
48 | return (buf); | ||
49 | } | ||
50 | |||
51 | dst = buf; | ||
52 | if (sign) | ||
53 | *dst++ = '-'; | ||
54 | |||
55 | if (decpt < 0 || decpt > ndigit) { | ||
56 | /* exponential format */ | ||
57 | if (--decpt < 0) { | ||
58 | sign = 1; | ||
59 | decpt = -decpt; | ||
60 | } else | ||
61 | sign = 0; | ||
62 | for (src = digits; *src != '\0'; ) | ||
63 | *dst++ = *src++; | ||
64 | *dst++ = 'e'; | ||
65 | if (sign) | ||
66 | *dst++ = '-'; | ||
67 | else | ||
68 | *dst++ = '+'; | ||
69 | if (decpt < 10) { | ||
70 | *dst++ = '0'; | ||
71 | *dst++ = '0' + decpt; | ||
72 | *dst = '\0'; | ||
73 | } else { | ||
74 | /* XXX - optimize */ | ||
75 | for (sign = decpt, i = 0; (sign /= 10) != 0; i++) | ||
76 | sign /= 10; | ||
77 | while (decpt != 0) { | ||
78 | dst[i--] = '0' + decpt % 10; | ||
79 | decpt /= 10; | ||
80 | } | ||
81 | } | ||
82 | } else { | ||
83 | /* standard format */ | ||
84 | for (i = 0, src = digits; i < decpt; i++) { | ||
85 | if (*src != '\0') | ||
86 | *dst++ = *src++; | ||
87 | else | ||
88 | *dst++ = '0'; | ||
89 | } | ||
90 | if (*src != '\0') { | ||
91 | *dst++ = '.'; /* XXX - locale-specific (LC_NUMERIC) */ | ||
92 | for (i = decpt; digits[i] != '\0'; i++) { | ||
93 | *dst++ = digits[i]; | ||
94 | } | ||
95 | } | ||
96 | *dst = '\0'; | ||
97 | } | ||
98 | return (buf); | ||
99 | } | ||