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)
37 static const char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93";
38 #endif /* LIBC_SCCS and not lint */
39 #else
40 __RCSID("$NetBSD: strtoul.c,v 1.2 2014/01/26 21:43:45 christos Exp $");
41 #endif
42
43 #include <limits.h>
44 #include <ctype.h>
45 #include <errno.h>
46 #include <stdlib.h>
47
48 /*
49 * Convert a string to an unsigned long integer.
50 *
51 * Ignores `locale' stuff. Assumes that the upper and lower case
52 * alphabets and digits are each contiguous.
53 *
54 * PUBLIC: #ifndef HAVE_STRTOUL
55 * PUBLIC: unsigned long strtoul __P((const char *, char **, int));
56 * PUBLIC: #endif
57 */
58 unsigned long
strtoul(const char * nptr,char ** endptr,register int base)59 strtoul(const char *nptr, char **endptr, 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