Statistics
| Branch: | Revision:

root / prex-0.9.0 / bsp / drv / lib / strtoul.c @ 03e9c04a

History | View | Annotate | Download (2.91 KB)

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. Neither the name of the University nor the names of its contributors
14
 *    may be used to endorse or promote products derived from this software
15
 *    without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27
 * SUCH DAMAGE.
28
 */
29

    
30
#include <ddi.h>
31
#include <machine/limits.h>
32

    
33
/*
34
 * Convert a string to an unsigned long integer.
35
 *
36
 * Ignores `locale' stuff.  Assumes that the upper and lower case
37
 * alphabets and digits are each contiguous.
38
 *
39
 * return ULONG_MAX if error.
40
 */
41
unsigned long
42
strtoul(const char *nptr, char **endptr, int base)
43
{
44
        const char *s;
45
        unsigned long acc, cutoff;
46
        int c;
47
        int neg, any, cutlim;
48

    
49
        /*
50
         * See strtol for comments as to the logic used.
51
         */
52
        s = nptr;
53
        do {
54
                c = (unsigned char) *s++;
55
        } while (isspace(c));
56
        if (c == '-') {
57
                neg = 1;
58
                c = *s++;
59
        } else {
60
                neg = 0;
61
                if (c == '+')
62
                        c = *s++;
63
        }
64
        if ((base == 0 || base == 16) &&
65
            c == '0' && (*s == 'x' || *s == 'X')) {
66
                c = s[1];
67
                s += 2;
68
                base = 16;
69
        }
70
        if (base == 0)
71
                base = c == '0' ? 8 : 10;
72

    
73
        cutoff = ULONG_MAX / base;
74
        cutlim = (int)(ULONG_MAX % (unsigned long)base);
75
        for (acc = 0, any = 0;; c = (unsigned char) *s++) {
76
                if (isdigit(c))
77
                        c -= '0';
78
                else if (isalpha(c))
79
                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
80
                else
81
                        break;
82
                if (c >= base)
83
                        break;
84
                if (any < 0)
85
                        continue;
86
                if (acc > cutoff || (acc == cutoff && c > cutlim)) {
87
                        any = -1;
88
                        acc = ULONG_MAX;
89
                } else {
90
                        any = 1;
91
                        acc *= (unsigned long)base;
92
                        acc += c;
93
                }
94
        }
95
        if (neg && any > 0)
96
                acc = -acc;
97
        if (endptr != 0)
98
                /* LINTED interface specification */
99
                *endptr = (char *)(any ? s - 1 : nptr);
100
        return (acc);
101
}