summaryrefslogtreecommitdiff
path: root/src/lib/libc/stdlib/strtol.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libc/stdlib/strtol.c')
-rw-r--r--src/lib/libc/stdlib/strtol.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/strtol.c b/src/lib/libc/stdlib/strtol.c
new file mode 100644
index 0000000000..e4ad557fd5
--- /dev/null
+++ b/src/lib/libc/stdlib/strtol.c
@@ -0,0 +1,150 @@
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * 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.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char *rcsid = "$OpenBSD: strtol.c,v 1.4 1996/08/19 08:33:51 tholo Exp $";
36#endif /* LIBC_SCCS and not lint */
37
38#include <ctype.h>
39#include <errno.h>
40#include <limits.h>
41#include <stdlib.h>
42
43
44/*
45 * Convert a string to a long integer.
46 *
47 * Ignores `locale' stuff. Assumes that the upper and lower case
48 * alphabets and digits are each contiguous.
49 */
50long
51strtol(nptr, endptr, base)
52 const char *nptr;
53 char **endptr;
54 register int base;
55{
56 register const char *s;
57 register long acc, cutoff;
58 register int c;
59 register int neg, any, cutlim;
60
61 /*
62 * Skip white space and pick up leading +/- sign if any.
63 * If base is 0, allow 0x for hex and 0 for octal, else
64 * assume decimal; if base is already 16, allow 0x.
65 */
66 s = nptr;
67 do {
68 c = (unsigned char) *s++;
69 } while (isspace(c));
70 if (c == '-') {
71 neg = 1;
72 c = *s++;
73 } else {
74 neg = 0;
75 if (c == '+')
76 c = *s++;
77 }
78 if ((base == 0 || base == 16) &&
79 c == '0' && (*s == 'x' || *s == 'X')) {
80 c = s[1];
81 s += 2;
82 base = 16;
83 }
84 if (base == 0)
85 base = c == '0' ? 8 : 10;
86
87 /*
88 * Compute the cutoff value between legal numbers and illegal
89 * numbers. That is the largest legal value, divided by the
90 * base. An input number that is greater than this value, if
91 * followed by a legal input character, is too big. One that
92 * is equal to this value may be valid or not; the limit
93 * between valid and invalid numbers is then based on the last
94 * digit. For instance, if the range for longs is
95 * [-2147483648..2147483647] and the input base is 10,
96 * cutoff will be set to 214748364 and cutlim to either
97 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
98 * a value > 214748364, or equal but the next digit is > 7 (or 8),
99 * the number is too big, and we will return a range error.
100 *
101 * Set any if any `digits' consumed; make it negative to indicate
102 * overflow.
103 */
104 cutoff = neg ? LONG_MIN : LONG_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 = LONG_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 = LONG_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}