1/*
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "config.h"
35
36#if defined(LIBC_SCCS) && !defined(lint)
37static const char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
38#endif /* LIBC_SCCS and not lint */
39
40#include <limits.h>
41#include <ctype.h>
42#include <errno.h>
43#include <stdlib.h>
44
45/*
46 * Convert a string to an unsigned long integer.
47 *
48 * Ignores `locale' stuff.  Assumes that the upper and lower case
49 * alphabets and digits are each contiguous.
50 *
51 * PUBLIC: #ifndef HAVE_STRTOUL
52 * PUBLIC: unsigned long strtoul __P((const char *, char **, int));
53 * PUBLIC: #endif
54 */
55unsigned long
56strtoul(nptr, endptr, base)
57	const char *nptr;
58	char **endptr;
59	register int base;
60{
61	register const char *s = nptr;
62	register unsigned long acc;
63	register int c;
64	register unsigned long cutoff;
65	register int neg = 0, any, cutlim;
66
67	/*
68	 * See strtol for comments as to the logic used.
69	 */
70	do {
71		c = *s++;
72	} while (isspace(c));
73	if (c == '-') {
74		neg = 1;
75		c = *s++;
76	} else if (c == '+')
77		c = *s++;
78	if ((base == 0 || base == 16) &&
79	    c == '0' && (*s == 'x' || *s == 'X')) {
80		c = s[1];
81		s += 2;
82		base = 16;
83	}
84	if (base == 0)
85		base = c == '0' ? 8 : 10;
86	cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
87	cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
88	for (acc = 0, any = 0;; c = *s++) {
89		if (isdigit(c))
90			c -= '0';
91		else if (isalpha(c))
92			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
93		else
94			break;
95		if (c >= base)
96			break;
97		if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
98			any = -1;
99		else {
100			any = 1;
101			acc *= base;
102			acc += c;
103		}
104	}
105	if (any < 0) {
106		acc = ULONG_MAX;
107		errno = ERANGE;
108	} else if (neg)
109		acc = -acc;
110	if (endptr != 0)
111		*endptr = (char *)(any ? s - 1 : nptr);
112	return (acc);
113}
114