1 /* $OpenBSD: strtoul.c,v 1.7 2005/08/08 08:05:37 espie Exp $ */ 2 /* 3 * Copyright (c) 1990 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 /* OPENBSD ORIGINAL: lib/libc/stdlib/strtoul.c */ 32 33 #include "includes.h" 34 #ifndef HAVE_STRTOUL 35 36 #include <ctype.h> 37 #include <errno.h> 38 #include <limits.h> 39 #include <stdlib.h> 40 41 /* 42 * Convert a string to an unsigned long integer. 43 * 44 * Ignores `locale' stuff. Assumes that the upper and lower case 45 * alphabets and digits are each contiguous. 46 */ 47 unsigned long 48 strtoul(const char *nptr, char **endptr, int base) 49 { 50 const char *s; 51 unsigned long acc, cutoff; 52 int c; 53 int neg, any, cutlim; 54 55 /* 56 * See strtol for comments as to the logic used. 57 */ 58 s = nptr; 59 do { 60 c = (unsigned char) *s++; 61 } while (isspace(c)); 62 if (c == '-') { 63 neg = 1; 64 c = *s++; 65 } else { 66 neg = 0; 67 if (c == '+') 68 c = *s++; 69 } 70 if ((base == 0 || base == 16) && 71 c == '0' && (*s == 'x' || *s == 'X')) { 72 c = s[1]; 73 s += 2; 74 base = 16; 75 } 76 if (base == 0) 77 base = c == '0' ? 8 : 10; 78 79 cutoff = ULONG_MAX / (unsigned long)base; 80 cutlim = ULONG_MAX % (unsigned long)base; 81 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 82 if (isdigit(c)) 83 c -= '0'; 84 else if (isalpha(c)) 85 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 86 else 87 break; 88 if (c >= base) 89 break; 90 if (any < 0) 91 continue; 92 if (acc > cutoff || acc == cutoff && c > cutlim) { 93 any = -1; 94 acc = ULONG_MAX; 95 errno = ERANGE; 96 } else { 97 any = 1; 98 acc *= (unsigned long)base; 99 acc += c; 100 } 101 } 102 if (neg && any > 0) 103 acc = -acc; 104 if (endptr != 0) 105 *endptr = (char *) (any ? s - 1 : nptr); 106 return (acc); 107 } 108 #endif /* !HAVE_STRTOUL */ 109