1/*	$OpenBSD: strtoull.c,v 1.9 2017/07/06 16:23:11 millert Exp $ */
2/*
3 * Copyright (c) 1992 The 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#include <sys/types.h>
32
33#include <ctype.h>
34#include <errno.h>
35#include <limits.h>
36#include <stdlib.h>
37
38/*
39 * Convert a string to an unsigned long long.
40 *
41 * Ignores `locale' stuff.  Assumes that the upper and lower case
42 * alphabets and digits are each contiguous.
43 */
44unsigned long long
45strtoull(const char *nptr, char **endptr, int base)
46{
47	const char *s;
48	unsigned long long acc, cutoff;
49	int c;
50	int neg, any, cutlim;
51
52	/*
53	 * See strtoll for comments as to the logic used.
54	 */
55	if (base < 0 || base == 1 || base > 36) {
56		if (endptr != 0)
57			*endptr = (char *)nptr;
58		errno = EINVAL;
59		return 0;
60	}
61
62	s = nptr;
63	do {
64		c = (unsigned char) *s++;
65	} while (isspace(c));
66	if (c == '-') {
67		neg = 1;
68		c = *s++;
69	} else {
70		neg = 0;
71		if (c == '+')
72			c = *s++;
73	}
74	if ((base == 0 || base == 16) && c == '0' &&
75	    (*s == 'x' || *s == 'X') && isxdigit((unsigned char)s[1])) {
76		c = s[1];
77		s += 2;
78		base = 16;
79	}
80	if (base == 0)
81		base = c == '0' ? 8 : 10;
82
83	cutoff = ULLONG_MAX / (unsigned long long)base;
84	cutlim = ULLONG_MAX % (unsigned long long)base;
85	for (acc = 0, any = 0;; c = (unsigned char) *s++) {
86		if (isdigit(c))
87			c -= '0';
88		else if (isalpha(c))
89			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
90		else
91			break;
92		if (c >= base)
93			break;
94		if (any < 0)
95			continue;
96		if (acc > cutoff || (acc == cutoff && c > cutlim)) {
97			any = -1;
98			acc = ULLONG_MAX;
99			errno = ERANGE;
100		} else {
101			any = 1;
102			acc *= (unsigned long long)base;
103			acc += c;
104		}
105	}
106	if (neg && any > 0)
107		acc = -acc;
108	if (endptr != 0)
109		*endptr = (char *) (any ? s - 1 : nptr);
110	return (acc);
111}
112DEF_STRONG(strtoull);
113
114__weak_alias(strtouq, strtoull);
115