1/* $Id: strtoul.c 276 2010-06-30 12:18:30Z nijtmans $ */
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. 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#if 0
33static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
34__RCSID("$NetBSD: strtoul.c,v 1.16 2003/08/07 16:43:45 agc Exp $");
35#endif
36
37#include <ctype.h>
38#include <errno.h>
39#include <limits.h>
40#include <stdlib.h>
41
42/*
43 * Convert a string to an unsigned long integer.
44 *
45 * Ignores `locale' stuff.  Assumes that the upper and lower case
46 * alphabets and digits are each contiguous.
47 */
48unsigned long
49strtoul(const char *nptr, char **endptr, int base)
50{
51	const char *s;
52	unsigned long acc, cutoff;
53	int c;
54	int neg, any, cutlim;
55
56	/*
57	 * See strtol for comments as to the logic used.
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) &&
72	    c == '0' && (*s == 'x' || *s == 'X')) {
73		c = s[1];
74		s += 2;
75		base = 16;
76	}
77	if (base == 0)
78		base = c == '0' ? 8 : 10;
79
80	cutoff = ULONG_MAX / (unsigned long)base;
81	cutlim = (int)(ULONG_MAX % (unsigned long)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 = ULONG_MAX;
96			errno = ERANGE;
97		} else {
98			any = 1;
99			acc *= (unsigned long)base;
100			acc += c;
101		}
102	}
103	if (neg && any > 0)
104		acc = -acc;
105	if (endptr != 0)
106		/* LINTED interface specification */
107		*endptr = (char *)(any ? s - 1 : nptr);
108	return (acc);
109}
110/*
111 * Local Variables:
112 * mode: c
113 * c-basic-offset: 8
114 * fill-column: 78
115 * End:
116 */
117