1 /* $OpenBSD: strtoumax.c,v 1.1 2006/01/13 17:58:09 millert Exp $ */ 2 3 /*- 4 * Copyright (c) 1992 The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <ctype.h> 33 #include <errno.h> 34 #include <inttypes.h> 35 36 /* 37 * Convert a string to a uintmax_t. 38 * 39 * Ignores `locale' stuff. Assumes that the upper and lower case 40 * alphabets and digits are each contiguous. 41 */ 42 uintmax_t 43 strtoumax(const char *nptr, char **endptr, int base) 44 { 45 const char *s; 46 uintmax_t acc, cutoff; 47 int c; 48 int neg, any, cutlim; 49 50 /* 51 * See strtoq for comments as to the logic used. 52 */ 53 s = nptr; 54 do { 55 c = (unsigned char) *s++; 56 } while (isspace(c)); 57 if (c == '-') { 58 neg = 1; 59 c = *s++; 60 } else { 61 neg = 0; 62 if (c == '+') 63 c = *s++; 64 } 65 if ((base == 0 || base == 16) && 66 c == '0' && (*s == 'x' || *s == 'X')) { 67 c = s[1]; 68 s += 2; 69 base = 16; 70 } 71 if (base == 0) 72 base = c == '0' ? 8 : 10; 73 74 /* BIONIC: avoid division and modulo for common cases */ 75 #define CASE_BASE(x) \ 76 case x: cutoff = UINTMAX_MAX / x; \ 77 cutlim = UINTMAX_MAX % x; \ 78 break 79 80 switch (base) { 81 CASE_BASE(8); 82 CASE_BASE(10); 83 CASE_BASE(16); 84 default: 85 cutoff = UINTMAX_MAX / base; 86 cutlim = UINTMAX_MAX % base; 87 } 88 89 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 90 if (isdigit(c)) 91 c -= '0'; 92 else if (isalpha(c)) 93 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 94 else 95 break; 96 if (c >= base) 97 break; 98 if (any < 0) 99 continue; 100 if (acc > cutoff || (acc == cutoff && c > cutlim)) { 101 any = -1; 102 acc = UINTMAX_MAX; 103 errno = ERANGE; 104 } else { 105 any = 1; 106 acc *= (uintmax_t)base; 107 acc += c; 108 } 109 } 110 if (neg && any > 0) 111 acc = -acc; 112 if (endptr != 0) 113 *endptr = (char *) (any ? s - 1 : nptr); 114 return (acc); 115 } 116
