1 /*- 2 * Copyright (c) 2002 Tim J. Robbins 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <stdlib.h> 31 #include <wchar.h> 32 #include <wctype.h> 33 34 /* 35 * Convert a string to a double-precision number. 36 * 37 * This is the wide-character counterpart of strtod(). So that we do not 38 * have to duplicate the code of strtod() here, we convert the supplied 39 * wide character string to multibyte and call strtod() on the result. 40 * This assumes that the multibyte encoding is compatible with ASCII 41 * for at least the digits, radix character and letters. 42 */ 43 double 44 wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr) 45 { 46 static const mbstate_t initial; 47 mbstate_t mbs; 48 double val; 49 char *buf, *end; 50 const wchar_t *wcp; 51 size_t len; 52 53 while (iswspace(*nptr)) 54 nptr++; 55 56 /* 57 * Convert the supplied numeric wide char. string to multibyte. 58 * 59 * We could attempt to find the end of the numeric portion of the 60 * wide char. string to avoid converting unneeded characters but 61 * choose not to bother; optimising the uncommon case where 62 * the input string contains a lot of text after the number 63 * duplicates a lot of strtod()'s functionality and slows down the 64 * most common cases. 65 */ 66 wcp = nptr; 67 mbs = initial; 68 if ((len = wcsrtombs(NULL, &wcp, 0, &mbs)) == (size_t)-1) { 69 if (endptr != NULL) 70 *endptr = (wchar_t *)nptr; 71 return (0.0); 72 } 73 if ((buf = malloc(len + 1)) == NULL) 74 return (0.0); 75 mbs = initial; 76 wcsrtombs(buf, &wcp, len + 1, &mbs); 77 78 /* Let strtod() do most of the work for us. */ 79 val = strtod(buf, &end); 80 81 /* 82 * We only know where the number ended in the _multibyte_ 83 * representation of the string. If the caller wants to know 84 * where it ended, count multibyte characters to find the 85 * corresponding position in the wide char string. 86 */ 87 if (endptr != NULL) 88 /* XXX Assume each wide char is one byte. */ 89 *endptr = (wchar_t *)nptr + (end - buf); 90 91 free(buf); 92 93 return (val); 94 } 95