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