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1e64b3ba JH |
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 | #if defined(LIBC_SCCS) && !defined(lint) | |
35 | static char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93"; | |
36 | #endif /* LIBC_SCCS and not lint */ | |
37 | ||
38 | #include <limits.h> | |
39 | #include <ctype.h> | |
40 | #include <errno.h> | |
41 | #include <stdlib.h> | |
42 | ||
43 | #include <sys/cdefs.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 | unsigned long | |
52 | strtoul(nptr, endptr, base) | |
53 | const char *nptr; | |
54 | char **endptr; | |
55 | register int base; | |
56 | { | |
57 | register const char *s = nptr; | |
58 | register unsigned long acc; | |
59 | register int c; | |
60 | register unsigned long cutoff; | |
61 | register int neg = 0, any, cutlim; | |
62 | ||
63 | /* | |
64 | * See strtol for comments as to the logic used. | |
65 | */ | |
66 | do { | |
67 | c = *s++; | |
68 | } while (isspace(c)); | |
69 | if (c == '-') { | |
70 | neg = 1; | |
71 | c = *s++; | |
72 | } else if (c == '+') | |
73 | c = *s++; | |
74 | if ((base == 0 || base == 16) && | |
75 | c == '0' && (*s == 'x' || *s == 'X')) { | |
76 | c = s[1]; | |
77 | s += 2; | |
78 | base = 16; | |
79 | } | |
80 | if (base == 0) | |
81 | base = c == '0' ? 8 : 10; | |
82 | cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; | |
83 | cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; | |
84 | for (acc = 0, any = 0;; c = *s++) { | |
85 | if (isdigit(c)) | |
86 | c -= '0'; | |
87 | else if (isalpha(c)) | |
88 | c -= isupper(c) ? 'A' - 10 : 'a' - 10; | |
89 | else | |
90 | break; | |
91 | if (c >= base) | |
92 | break; | |
93 | if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) | |
94 | any = -1; | |
95 | else { | |
96 | any = 1; | |
97 | acc *= base; | |
98 | acc += c; | |
99 | } | |
100 | } | |
101 | if (any < 0) { | |
102 | acc = ULONG_MAX; | |
103 | errno = ERANGE; | |
104 | } else if (neg) | |
105 | acc = -acc; | |
106 | if (endptr != 0) | |
107 | *endptr = (char *)(any ? s - 1 : nptr); | |
108 | return (acc); | |
109 | } |