Use CSTD and remove local CSTD settings which are no longer needed.
[dragonfly.git] / lib / libstand / strtol.c
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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.
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32 *
33 * @(#)strtol.c 8.1 (Berkeley) 6/4/93
ff2aef30 34 * $DragonFly: src/lib/libstand/strtol.c,v 1.4 2005/12/11 02:27:26 swildner Exp $
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35 */
36
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37#include "stand.h"
38#include <limits.h>
39
40/*
41 * Convert a string to a long integer.
42 *
43 * Ignores `locale' stuff. Assumes that the upper and lower case
44 * alphabets and digits are each contiguous.
45 */
46long
ff2aef30 47strtol(const char *nptr, char **endptr, int base)
984263bc 48{
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49 const char *s;
50 unsigned long acc;
51 unsigned char c;
52 unsigned long cutoff;
53 int neg = 0, any, cutlim;
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54
55 /* Be sensible about NULL strings */
56 if (nptr == NULL)
57 nptr = "";
58 s = nptr;
59
60 /*
61 * Skip white space and pick up leading +/- sign if any.
62 * If base is 0, allow 0x for hex and 0 for octal, else
63 * assume decimal; if base is already 16, allow 0x.
64 */
65 do {
66 c = *s++;
67 } while (isspace(c));
68 if (c == '-') {
69 neg = 1;
70 c = *s++;
71 } else if (c == '+')
72 c = *s++;
73 if ((base == 0 || base == 16) &&
74 c == '0' && (*s == 'x' || *s == 'X')) {
75 c = s[1];
76 s += 2;
77 base = 16;
78 }
79 if (base == 0)
80 base = c == '0' ? 8 : 10;
81
82 /*
83 * Compute the cutoff value between legal numbers and illegal
84 * numbers. That is the largest legal value, divided by the
85 * base. An input number that is greater than this value, if
86 * followed by a legal input character, is too big. One that
87 * is equal to this value may be valid or not; the limit
88 * between valid and invalid numbers is then based on the last
89 * digit. For instance, if the range for longs is
90 * [-2147483648..2147483647] and the input base is 10,
91 * cutoff will be set to 214748364 and cutlim to either
92 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
93 * a value > 214748364, or equal but the next digit is > 7 (or 8),
94 * the number is too big, and we will return a range error.
95 *
96 * Set any if any `digits' consumed; make it negative to indicate
97 * overflow.
98 */
99 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
100 cutlim = cutoff % (unsigned long)base;
101 cutoff /= (unsigned long)base;
102 for (acc = 0, any = 0;; c = *s++) {
103 if (!isascii(c))
104 break;
105 if (isdigit(c))
106 c -= '0';
107 else if (isalpha(c))
108 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
109 else
110 break;
111 if (c >= base)
112 break;
113 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
114 any = -1;
115 else {
116 any = 1;
117 acc *= base;
118 acc += c;
119 }
120 }
121 if (any < 0) {
122 acc = neg ? LONG_MIN : LONG_MAX;
123 errno = ERANGE;
124 } else if (neg)
125 acc = -acc;
126 if (endptr != 0)
127 *endptr = (char *)(any ? s - 1 : nptr);
128 return (acc);
129}