1 /* SPDX-License-Identifier: BSD-3-Clause */
2
3 /*
4 * Copyright (c) 1990 Regents of the University of California.
5 * 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 #include <limits.h>
33 #include <ctype.h>
34 #include <errno.h>
35 #include <stdlib.h>
36
37 /*
38 * Convert a string to an unsigned long long integer.
39 *
40 * Ignores `locale' stuff. Assumes that the upper and lower case
41 * alphabets and digits are each contiguous.
42 */
strtoull(const char * nptr,char ** endptr,register int base)43 unsigned long long strtoull(const char *nptr, char **endptr, register int base)
44 {
45 register const char *s = nptr;
46 register unsigned long long acc;
47 register int c;
48 register unsigned long long cutoff;
49 register int neg = 0, any, cutlim;
50
51 /*
52 * See strtol for comments as to the logic used.
53 */
54 do {
55 c = *s++;
56 } while (isspace(c) != 0);
57 if (c == '-') {
58 neg = 1;
59 c = *s++;
60 } else if (c == '+') {
61 c = *s++;
62 }
63
64 if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X')) {
65 c = s[1];
66 s += 2;
67 base = 16;
68 }
69
70 if (base == 0) {
71 base = c == '0' ? 8 : 10;
72 }
73
74 cutoff = (unsigned long long)ULLONG_MAX / (unsigned long long)base;
75 cutlim = (unsigned long long)ULLONG_MAX % (unsigned long long)base;
76 for (acc = 0, any = 0;; c = *s++) {
77 if (isdigit(c) != 0) {
78 c -= '0';
79 } else if (isalpha(c) != 0) {
80 c -= isupper(c) != 0 ? 'A' - 10 : 'a' - 10;
81 } else {
82 break;
83 }
84 if (c >= base) {
85 break;
86 }
87 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) {
88 any = -1;
89 } else {
90 any = 1;
91 acc *= base;
92 acc += c;
93 }
94 }
95 if (any < 0) {
96 acc = ULLONG_MAX;
97 errno = ERANGE;
98 } else if (neg) {
99 acc = -acc;
100 }
101 if (endptr != NULL) {
102 *endptr = (char *)(any ? (char *)s - 1 : nptr);
103 }
104 return acc;
105 }
106
