1 /* $OpenBSD: strtoll.c,v 1.8 2014/09/13 20:10:12 schwarze 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 #include <sys/types.h>
32
33 #include <ctype.h>
34 #include <errno.h>
35 #include <limits.h>
36 #include <stdlib.h>
37
38 /*
39 * Convert a string to a long long.
40 *
41 * Ignores `locale' stuff. Assumes that the upper and lower case
42 * alphabets and digits are each contiguous.
43 */
44 long long
strtoll(const char * nptr,char ** endptr,int base)45 strtoll(const char *nptr, char **endptr, int base)
46 {
47 const char *s;
48 long long acc, cutoff;
49 int c;
50 int neg, any, cutlim;
51
52 /*
53 * Ensure that base is between 2 and 36 inclusive, or the special
54 * value of 0.
55 */
56 if (base < 0 || base == 1 || base > 36) {
57 if (endptr != 0)
58 *endptr = (char *)nptr;
59 errno = EINVAL;
60 return 0;
61 }
62
63 /*
64 * Skip white space and pick up leading +/- sign if any.
65 * If base is 0, allow 0x for hex and 0 for octal, else
66 * assume decimal; if base is already 16, allow 0x.
67 */
68 s = nptr;
69 do {
70 c = (unsigned char) *s++;
71 } while (isspace(c));
72 if (c == '-') {
73 neg = 1;
74 c = *s++;
75 } else {
76 neg = 0;
77 if (c == '+')
78 c = *s++;
79 }
80 if ((base == 0 || base == 16) &&
81 c == '0' && (*s == 'x' || *s == 'X')) {
82 c = s[1];
83 s += 2;
84 base = 16;
85 }
86 if (base == 0)
87 base = c == '0' ? 8 : 10;
88
89 /*
90 * Compute the cutoff value between legal numbers and illegal
91 * numbers. That is the largest legal value, divided by the
92 * base. An input number that is greater than this value, if
93 * followed by a legal input character, is too big. One that
94 * is equal to this value may be valid or not; the limit
95 * between valid and invalid numbers is then based on the last
96 * digit. For instance, if the range for long longs is
97 * [-9223372036854775808..9223372036854775807] and the input base
98 * is 10, cutoff will be set to 922337203685477580 and cutlim to
99 * either 7 (neg==0) or 8 (neg==1), meaning that if we have
100 * accumulated a value > 922337203685477580, or equal but the
101 * next digit is > 7 (or 8), the number is too big, and we will
102 * return a range error.
103 *
104 * Set any if any `digits' consumed; make it negative to indicate
105 * overflow.
106 */
107 cutoff = neg ? LLONG_MIN : LLONG_MAX;
108 cutlim = cutoff % base;
109 cutoff /= base;
110 if (neg) {
111 if (cutlim > 0) {
112 cutlim -= base;
113 cutoff += 1;
114 }
115 cutlim = -cutlim;
116 }
117 for (acc = 0, any = 0;; c = (unsigned char) *s++) {
118 if (isdigit(c))
119 c -= '0';
120 else if (isalpha(c))
121 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
122 else
123 break;
124 if (c >= base)
125 break;
126 if (any < 0)
127 continue;
128 if (neg) {
129 if (acc < cutoff || (acc == cutoff && c > cutlim)) {
130 any = -1;
131 acc = LLONG_MIN;
132 errno = ERANGE;
133 } else {
134 any = 1;
135 acc *= base;
136 acc -= c;
137 }
138 } else {
139 if (acc > cutoff || (acc == cutoff && c > cutlim)) {
140 any = -1;
141 acc = LLONG_MAX;
142 errno = ERANGE;
143 } else {
144 any = 1;
145 acc *= base;
146 acc += c;
147 }
148 }
149 }
150 if (endptr != 0)
151 *endptr = (char *) (any ? s - 1 : nptr);
152 return (acc);
153 }
154
155 __strong_alias(strtoq, strtoll);
156