1 /*
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Copyright (c) 2011 The FreeBSD Foundation
6 * All rights reserved.
7 * Portions of this software were developed by David Chisnall
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)strtoul.c 8.1 (Berkeley) 6/4/93
35 * $FreeBSD: head/lib/libstand/strtoul.c 247001 2013-02-19 17:09:23Z kientzle $
36 */
37
38 #include "stand.h"
39 #include <limits.h>
40
41 /*
42 * Convert a string to an unsigned long integer.
43 *
44 * Assumes that the upper and lower case
45 * alphabets and digits are each contiguous.
46 */
47 unsigned long
strtoul(const char * __restrict nptr,char ** __restrict endptr,int base)48 strtoul(const char * __restrict nptr, char ** __restrict endptr, int base)
49 {
50 const char *s;
51 unsigned long acc;
52 char c;
53 unsigned long cutoff;
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 = *s++;
62 } while (isspace((unsigned char)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 ((s[1] >= '0' && s[1] <= '9') ||
74 (s[1] >= 'A' && s[1] <= 'F') ||
75 (s[1] >= 'a' && s[1] <= 'f'))) {
76 c = s[1];
77 s += 2;
78 base = 16;
79 }
80 if (base == 0)
81 base = c == '0' ? 8 : 10;
82 acc = any = 0;
83 if (base < 2 || base > 36)
84 goto noconv;
85
86 cutoff = ULONG_MAX / base;
87 cutlim = ULONG_MAX % base;
88 for ( ; ; c = *s++) {
89 if (c >= '0' && c <= '9')
90 c -= '0';
91 else if (c >= 'A' && c <= 'Z')
92 c -= 'A' - 10;
93 else if (c >= 'a' && c <= 'z')
94 c -= 'a' - 10;
95 else
96 break;
97 if (c >= base)
98 break;
99 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
100 any = -1;
101 else {
102 any = 1;
103 acc *= base;
104 acc += c;
105 }
106 }
107 if (any < 0) {
108 acc = ULONG_MAX;
109 errno = ERANGE;
110 } else if (!any) {
111 noconv:
112 errno = EINVAL;
113 } else if (neg)
114 acc = -acc;
115 if (endptr != NULL)
116 *endptr = (char *)(any ? s - 1 : nptr);
117 return (acc);
118 }
119