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Darren Tucker81eb5d52005-06-01 21:39:33 +10001/* OPENBSD ORIGINAL: lib/libc/stdlib/strtoll.c */
2
3/*-
4 * Copyright (c) 1992 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include "includes.h"
33#ifndef HAVE_STRTOLL
34
35#if defined(LIBC_SCCS) && !defined(lint)
36static const char rcsid[] = "$OpenBSD: strtoll.c,v 1.4 2005/03/30 18:51:49 pat Exp $";
37#endif /* LIBC_SCCS and not lint */
38
39#include <sys/types.h>
40
41#include <ctype.h>
42#include <errno.h>
43#include <limits.h>
44#include <stdlib.h>
45
46/*
47 * Convert a string to a long long.
48 *
49 * Ignores `locale' stuff. Assumes that the upper and lower case
50 * alphabets and digits are each contiguous.
51 */
52long long
53strtoll(const char *nptr, char **endptr, int base)
54{
55 const char *s;
56 long long acc, cutoff;
57 int c;
58 int neg, any, cutlim;
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 s = nptr;
66 do {
67 c = (unsigned char) *s++;
68 } while (isspace(c));
69 if (c == '-') {
70 neg = 1;
71 c = *s++;
72 } else {
73 neg = 0;
74 if (c == '+')
75 c = *s++;
76 }
77 if ((base == 0 || base == 16) &&
78 c == '0' && (*s == 'x' || *s == 'X')) {
79 c = s[1];
80 s += 2;
81 base = 16;
82 }
83 if (base == 0)
84 base = c == '0' ? 8 : 10;
85
86 /*
87 * Compute the cutoff value between legal numbers and illegal
88 * numbers. That is the largest legal value, divided by the
89 * base. An input number that is greater than this value, if
90 * followed by a legal input character, is too big. One that
91 * is equal to this value may be valid or not; the limit
92 * between valid and invalid numbers is then based on the last
93 * digit. For instance, if the range for long longs is
94 * [-9223372036854775808..9223372036854775807] and the input base
95 * is 10, cutoff will be set to 922337203685477580 and cutlim to
96 * either 7 (neg==0) or 8 (neg==1), meaning that if we have
97 * accumulated a value > 922337203685477580, or equal but the
98 * next digit is > 7 (or 8), the number is too big, and we will
99 * return a range error.
100 *
101 * Set any if any `digits' consumed; make it negative to indicate
102 * overflow.
103 */
104 cutoff = neg ? LLONG_MIN : LLONG_MAX;
105 cutlim = cutoff % base;
106 cutoff /= base;
107 if (neg) {
108 if (cutlim > 0) {
109 cutlim -= base;
110 cutoff += 1;
111 }
112 cutlim = -cutlim;
113 }
114 for (acc = 0, any = 0;; c = (unsigned char) *s++) {
115 if (isdigit(c))
116 c -= '0';
117 else if (isalpha(c))
118 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
119 else
120 break;
121 if (c >= base)
122 break;
123 if (any < 0)
124 continue;
125 if (neg) {
126 if (acc < cutoff || (acc == cutoff && c > cutlim)) {
127 any = -1;
128 acc = LLONG_MIN;
129 errno = ERANGE;
130 } else {
131 any = 1;
132 acc *= base;
133 acc -= c;
134 }
135 } else {
136 if (acc > cutoff || (acc == cutoff && c > cutlim)) {
137 any = -1;
138 acc = LLONG_MAX;
139 errno = ERANGE;
140 } else {
141 any = 1;
142 acc *= base;
143 acc += c;
144 }
145 }
146 }
147 if (endptr != 0)
148 *endptr = (char *) (any ? s - 1 : nptr);
149 return (acc);
150}
151#endif /* HAVE_STRTOLL */