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 <stdio.h> 24 #include <stdlib.h> 25 #include <string.h> 26 27 extern char *__dtoa(double, int, int, int *, int *, char **); 28 extern void __freedtoa(char *); 29 static char *__cvt(double, int, int *, int *, int, int); 30 31 static char * 32 __cvt(double value, int ndigit, int *decpt, int *sign, int fmode, int pad) 33 { 34 static char *s; 35 char *p, *rve, c; 36 size_t siz; 37 38 if (ndigit == 0) { 39 *sign = value < 0.0; 40 *decpt = 0; 41 return (""); 42 } 43 44 if (s) { 45 free(s); 46 s = NULL; 47 } 48 49 if (ndigit < 0) 50 siz = -ndigit + 1; 51 else 52 siz = ndigit + 1; 53 54 55 /* __dtoa() doesn't allocate space for 0 so we do it by hand */ 56 if (value == 0.0) { 57 *decpt = 1 - fmode; /* 1 for 'e', 0 for 'f' */ 58 *sign = 0; 59 if ((rve = s = (char *)malloc(siz)) == NULL) 60 return(NULL); 61 *rve++ = '0'; 62 *rve = '\0'; 63 } else { 64 p = __dtoa(value, fmode + 2, ndigit, decpt, sign, &rve); 65 if (p == NULL) 66 return (NULL); 67 if (*decpt == 9999) { 68 /* Infinity or Nan, convert to inf or nan like printf */ 69 *decpt = 0; 70 c = *p; 71 __freedtoa(p); 72 return(c == 'I' ? "inf" : "nan"); 73 } 74 /* Make a local copy and adjust rve to be in terms of s */ 75 if (pad && fmode) 76 siz += *decpt; 77 if ((s = (char *)malloc(siz)) == NULL) { 78 __freedtoa(p); 79 return(NULL); 80 } 81 (void) strlcpy(s, p, siz); 82 rve = s + (rve - p); 83 __freedtoa(p); 84 } 85 86 /* Add trailing zeros */ 87 if (pad) { 88 siz -= rve - s; 89 while (--siz) 90 *rve++ = '0'; 91 *rve = '\0'; 92 } 93 94 return(s); 95 } 96 97 char * 98 ecvt(double value, int ndigit, int *decpt, int *sign) 99 { 100 return(__cvt(value, ndigit, decpt, sign, 0, 1)); 101 } 102 103 char * 104 fcvt(double value, int ndigit, int *decpt, int *sign) 105 { 106 return(__cvt(value, ndigit, decpt, sign, 1, 1)); 107 } 108