1 /* $OpenBSD: ecvt.c,v 1.1 2002/12/02 15:38:54 millert Exp $ */ 2 3 /* 4 * Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char rcsid[] = "$OpenBSD: ecvt.c,v 1.1 2002/12/02 15:38:54 millert Exp $"; 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 38 extern char *__dtoa(double, int, int, int *, int *, char **); 39 static char *__cvt(double, int, int *, int *, int, int); 40 41 static char * 42 __cvt(double value, int ndigit, int *decpt, int *sign, int fmode, int pad) 43 { 44 static char *s; 45 char *p, *rve; 46 size_t siz; 47 48 if (ndigit == 0) { 49 *sign = value < 0.0; 50 *decpt = 0; 51 return (""); 52 } 53 54 if (s) { 55 free(s); 56 s = NULL; 57 } 58 59 if (ndigit < 0) 60 siz = -ndigit + 1; 61 else 62 siz = ndigit + 1; 63 64 65 /* __dtoa() doesn't allocate space for 0 so we do it by hand */ 66 if (value == 0.0) { 67 *decpt = 1 - fmode; /* 1 for 'e', 0 for 'f' */ 68 *sign = 0; 69 if ((rve = s = (char *)malloc(siz)) == NULL) 70 return(NULL); 71 *rve++ = '0'; 72 *rve = '\0'; 73 } else { 74 p = __dtoa(value, fmode + 2, ndigit, decpt, sign, &rve); 75 if (*decpt == 9999) { 76 /* Nan or Infinity */ 77 *decpt = 0; 78 return(p); 79 } 80 /* make a local copy and adjust rve to be in terms of s */ 81 if (pad && fmode) 82 siz += *decpt; 83 if ((s = (char *)malloc(siz)) == NULL) 84 return(NULL); 85 (void) strlcpy(s, p, siz); 86 rve = s + (rve - p); 87 } 88 89 /* Add trailing zeros (unless we got NaN or Inf) */ 90 if (pad && *decpt != 9999) { 91 siz -= rve - s; 92 while (--siz) 93 *rve++ = '0'; 94 *rve = '\0'; 95 } 96 97 return(s); 98 } 99 100 char * 101 ecvt(double value, int ndigit, int *decpt, int *sign) 102 { 103 return(__cvt(value, ndigit, decpt, sign, 0, 1)); 104 } 105 106 char * 107 fcvt(double value, int ndigit, int *decpt, int *sign) 108 { 109 return(__cvt(value, ndigit, decpt, sign, 1, 1)); 110 } 111