1 /* $OpenBSD: ecvt.c,v 1.5 2006/01/10 16:18:37 millert 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 static char *__cvt(double, int, int *, int *, int, int); 29 30 static char * 31 __cvt(double value, int ndigit, int *decpt, int *sign, int fmode, int pad) 32 { 33 static char *s; 34 char *p, *rve; 35 size_t siz; 36 37 if (ndigit == 0) { 38 *sign = value < 0.0; 39 *decpt = 0; 40 return (""); 41 } 42 43 if (s) { 44 free(s); 45 s = NULL; 46 } 47 48 if (ndigit < 0) 49 siz = -ndigit + 1; 50 else 51 siz = ndigit + 1; 52 53 54 /* __dtoa() doesn't allocate space for 0 so we do it by hand */ 55 if (value == 0.0) { 56 *decpt = 1 - fmode; /* 1 for 'e', 0 for 'f' */ 57 *sign = 0; 58 if ((rve = s = (char *)malloc(siz)) == NULL) 59 return(NULL); 60 *rve++ = '0'; 61 *rve = '\0'; 62 } else { 63 p = __dtoa(value, fmode + 2, ndigit, decpt, sign, &rve); 64 if (*decpt == 9999) { 65 /* Infinity or Nan, convert to inf or nan like printf */ 66 *decpt = 0; 67 return(*p == 'I' ? "inf" : "nan"); 68 } 69 /* Make a local copy and adjust rve to be in terms of s */ 70 if (pad && fmode) 71 siz += *decpt; 72 if ((s = (char *)malloc(siz)) == NULL) 73 return(NULL); 74 (void) strlcpy(s, p, siz); 75 rve = s + (rve - p); 76 } 77 78 /* Add trailing zeros */ 79 if (pad) { 80 siz -= rve - s; 81 while (--siz) 82 *rve++ = '0'; 83 *rve = '\0'; 84 } 85 86 return(s); 87 } 88 89 char * 90 ecvt(double value, int ndigit, int *decpt, int *sign) 91 { 92 return(__cvt(value, ndigit, decpt, sign, 0, 1)); 93 } 94 95 char * 96 fcvt(double value, int ndigit, int *decpt, int *sign) 97 { 98 return(__cvt(value, ndigit, decpt, sign, 1, 1)); 99 } 100