1 /* $OpenBSD: strtoumax.c,v 1.4 2017/07/06 16:23:11 millert Exp $ */ 2 /* 3 * Copyright (c) 1992 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <ctype.h> 32 #include <errno.h> 33 #include <inttypes.h> 34 35 /* 36 * Convert a string to a uintmax_t. 37 * 38 * Ignores `locale' stuff. Assumes that the upper and lower case 39 * alphabets and digits are each contiguous. 40 */ 41 uintmax_t 42 strtoumax(const char *nptr, char **endptr, int base) 43 { 44 const char *s; 45 uintmax_t acc, cutoff; 46 int c; 47 int neg, any, cutlim; 48 49 /* 50 * See strtoimax for comments as to the logic used. 51 */ 52 if (base < 0 || base == 1 || base > 36) { 53 if (endptr != 0) 54 *endptr = (char *)nptr; 55 errno = EINVAL; 56 return 0; 57 } 58 59 s = nptr; 60 do { 61 c = (unsigned char) *s++; 62 } while (isspace(c)); 63 if (c == '-') { 64 neg = 1; 65 c = *s++; 66 } else { 67 neg = 0; 68 if (c == '+') 69 c = *s++; 70 } 71 if ((base == 0 || base == 16) && c == '0' && 72 (*s == 'x' || *s == 'X') && isxdigit((unsigned char)s[1])) { 73 c = s[1]; 74 s += 2; 75 base = 16; 76 } 77 if (base == 0) 78 base = c == '0' ? 8 : 10; 79 80 cutoff = UINTMAX_MAX / (uintmax_t)base; 81 cutlim = UINTMAX_MAX % (uintmax_t)base; 82 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 83 if (isdigit(c)) 84 c -= '0'; 85 else if (isalpha(c)) 86 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 87 else 88 break; 89 if (c >= base) 90 break; 91 if (any < 0) 92 continue; 93 if (acc > cutoff || (acc == cutoff && c > cutlim)) { 94 any = -1; 95 acc = UINTMAX_MAX; 96 errno = ERANGE; 97 } else { 98 any = 1; 99 acc *= (uintmax_t)base; 100 acc += c; 101 } 102 } 103 if (neg && any > 0) 104 acc = -acc; 105 if (endptr != 0) 106 *endptr = (char *) (any ? s - 1 : nptr); 107 return (acc); 108 } 109 DEF_STRONG(strtoumax); 110