1 /* $OpenBSD: strtoll.c,v 1.6 2005/11/10 10:00:17 espie Exp $ */
2 /*-
3 * Copyright (c) 1992 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 /* OPENBSD ORIGINAL: lib/libc/stdlib/strtoll.c */
32
33 #include "includes.h"
34 #ifndef HAVE_STRTOLL
35
36 #include <sys/types.h>
37
38 #include <ctype.h>
39 #include <errno.h>
40 #include <limits.h>
41 #include <stdlib.h>
42
43 /*
44 * Convert a string to a long long.
45 *
46 * Ignores `locale' stuff. Assumes that the upper and lower case
47 * alphabets and digits are each contiguous.
48 */
49 long long
strtoll(const char * nptr,char ** endptr,int base)50 strtoll(const char *nptr, char **endptr, int base)
51 {
52 const char *s;
53 long long acc, cutoff;
54 int c;
55 int neg, any, cutlim;
56
57 /*
58 * Skip white space and pick up leading +/- sign if any.
59 * If base is 0, allow 0x for hex and 0 for octal, else
60 * assume decimal; if base is already 16, allow 0x.
61 */
62 s = nptr;
63 do {
64 c = (unsigned char) *s++;
65 } while (isspace(c));
66 if (c == '-') {
67 neg = 1;
68 c = *s++;
69 } else {
70 neg = 0;
71 if (c == '+')
72 c = *s++;
73 }
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
83 /*
84 * Compute the cutoff value between legal numbers and illegal
85 * numbers. That is the largest legal value, divided by the
86 * base. An input number that is greater than this value, if
87 * followed by a legal input character, is too big. One that
88 * is equal to this value may be valid or not; the limit
89 * between valid and invalid numbers is then based on the last
90 * digit. For instance, if the range for long longs is
91 * [-9223372036854775808..9223372036854775807] and the input base
92 * is 10, cutoff will be set to 922337203685477580 and cutlim to
93 * either 7 (neg==0) or 8 (neg==1), meaning that if we have
94 * accumulated a value > 922337203685477580, or equal but the
95 * next digit is > 7 (or 8), the number is too big, and we will
96 * return a range error.
97 *
98 * Set any if any `digits' consumed; make it negative to indicate
99 * overflow.
100 */
101 cutoff = neg ? LLONG_MIN : LLONG_MAX;
102 cutlim = cutoff % base;
103 cutoff /= base;
104 if (neg) {
105 if (cutlim > 0) {
106 cutlim -= base;
107 cutoff += 1;
108 }
109 cutlim = -cutlim;
110 }
111 for (acc = 0, any = 0;; c = (unsigned char) *s++) {
112 if (isdigit(c))
113 c -= '0';
114 else if (isalpha(c))
115 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
116 else
117 break;
118 if (c >= base)
119 break;
120 if (any < 0)
121 continue;
122 if (neg) {
123 if (acc < cutoff || (acc == cutoff && c > cutlim)) {
124 any = -1;
125 acc = LLONG_MIN;
126 errno = ERANGE;
127 } else {
128 any = 1;
129 acc *= base;
130 acc -= c;
131 }
132 } else {
133 if (acc > cutoff || (acc == cutoff && c > cutlim)) {
134 any = -1;
135 acc = LLONG_MAX;
136 errno = ERANGE;
137 } else {
138 any = 1;
139 acc *= base;
140 acc += c;
141 }
142 }
143 }
144 if (endptr != 0)
145 *endptr = (char *) (any ? s - 1 : nptr);
146 return (acc);
147 }
148 #endif /* HAVE_STRTOLL */
149