1/* $NetBSD: strtoul.c,v 1.1.1.2 2008/05/18 14:29:39 aymeric Exp $ */ 2 3/* 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include "config.h" 37 38#if defined(LIBC_SCCS) && !defined(lint) 39static const char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93"; 40#endif /* LIBC_SCCS and not lint */ 41 42#include <limits.h> 43#include <ctype.h> 44#include <errno.h> 45#include <stdlib.h> 46 47/* 48 * Convert a string to an unsigned long integer. 49 * 50 * Ignores `locale' stuff. Assumes that the upper and lower case 51 * alphabets and digits are each contiguous. 52 * 53 * PUBLIC: #ifndef HAVE_STRTOUL 54 * PUBLIC: unsigned long strtoul __P((const char *, char **, int)); 55 * PUBLIC: #endif 56 */ 57unsigned long 58strtoul(const char *nptr, char **endptr, register int base) 59{ 60 register const char *s = nptr; 61 register unsigned long acc; 62 register int c; 63 register unsigned long cutoff; 64 register int neg = 0, any, cutlim; 65 66 /* 67 * See strtol for comments as to the logic used. 68 */ 69 do { 70 c = *s++; 71 } while (isspace(c)); 72 if (c == '-') { 73 neg = 1; 74 c = *s++; 75 } else if (c == '+') 76 c = *s++; 77 if ((base == 0 || base == 16) && 78 c == '0' && (*s == 'x' || *s == 'X')) { 79 c = s[1]; 80 s += 2; 81 base = 16; 82 } 83 if (base == 0) 84 base = c == '0' ? 8 : 10; 85 cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; 86 cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; 87 for (acc = 0, any = 0;; c = *s++) { 88 if (isdigit(c)) 89 c -= '0'; 90 else if (isalpha(c)) 91 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 92 else 93 break; 94 if (c >= base) 95 break; 96 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) 97 any = -1; 98 else { 99 any = 1; 100 acc *= base; 101 acc += c; 102 } 103 } 104 if (any < 0) { 105 acc = ULONG_MAX; 106 errno = ERANGE; 107 } else if (neg) 108 acc = -acc; 109 if (endptr != 0) 110 *endptr = (char *)(any ? s - 1 : nptr); 111 return (acc); 112} 113