diff options
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 | } | ||
