1
/* $OpenBSD: strtoul.c,v 1.7 2005/08/08 08:05:37 espie Exp $ */
3
* Copyright (c) 1990 Regents of the University of California.
6
* Redistribution and use in source and binary forms, with or without
7
* modification, are permitted provided that the following conditions
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.
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
37
* Convert a string to an unsigned long integer.
39
* Ignores `locale' stuff. Assumes that the upper and lower case
40
* alphabets and digits are each contiguous.
43
strtoul(const char *nptr, char **endptr, int base)
46
unsigned long acc, cutoff;
51
* See strtol for comments as to the logic used.
55
c = (unsigned char) *s++;
65
if ((base == 0 || base == 16) &&
66
c == '0' && (*s == 'x' || *s == 'X')) {
72
base = c == '0' ? 8 : 10;
74
cutoff = ULONG_MAX / (unsigned long)base;
75
cutlim = ULONG_MAX % (unsigned long)base;
76
for (acc = 0, any = 0;; c = (unsigned char) *s++) {
80
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
87
if (acc > cutoff || (acc == cutoff && c > cutlim)) {
93
acc *= (unsigned long)base;
100
*endptr = (char *) (any ? s - 1 : nptr);