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.
32 */
33
34 #include "config.h"
35
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static const char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93";
38 #endif /* LIBC_SCCS and not lint */
39 #else
40 __RCSID("$NetBSD: strtol.c,v 1.2 2014/01/26 21:43:45 christos Exp $");
41 #endif
42
43 #include <limits.h>
44 #include <ctype.h>
45 #include <errno.h>
46 #include <stdlib.h>
47
48 /*
49 * Convert a string to a long integer.
50 *
51 * Ignores `locale' stuff. Assumes that the upper and lower case
52 * alphabets and digits are each contiguous.
53 *
54 * PUBLIC: #ifndef HAVE_STRTOL
55 * PUBLIC: long strtol __P((const char *, char **, int));
56 * PUBLIC: #endif
57 */
58 long
strtol(const char * nptr,char ** endptr,register int base)59 strtol(const char *nptr, char **endptr, register int base)
60 {
61 register const char *s = nptr;
62 register unsigned long acc;
63 register int c;
64 register unsigned long cutoff;
65 register int neg = 0, any, cutlim;
66
67 /*
68 * Skip white space and pick up leading +/- sign if any.
69 * If base is 0, allow 0x for hex and 0 for octal, else
70 * assume decimal; if base is already 16, allow 0x.
71 */
72 do {
73 c = *s++;
74 } while (isspace(c));
75 if (c == '-') {
76 neg = 1;
77 c = *s++;
78 } else if (c == '+')
79 c = *s++;
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 longs is
97 * [-2147483648..2147483647] and the input base is 10,
98 * cutoff will be set to 214748364 and cutlim to either
99 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
100 * a value > 214748364, or equal but the next digit is > 7 (or 8),
101 * the number is too big, and we will return a range error.
102 *
103 * Set any if any `digits' consumed; make it negative to indicate
104 * overflow.
105 */
106 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
107 cutlim = cutoff % (unsigned long)base;
108 cutoff /= (unsigned long)base;
109 for (acc = 0, any = 0;; c = *s++) {
110 if (isdigit(c))
111 c -= '0';
112 else if (isalpha(c))
113 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
114 else
115 break;
116 if (c >= base)
117 break;
118 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
119 any = -1;
120 else {
121 any = 1;
122 acc *= base;
123 acc += c;
124 }
125 }
126 if (any < 0) {
127 acc = neg ? LONG_MIN : LONG_MAX;
128 errno = ERANGE;
129 } else if (neg)
130 acc = -acc;
131 if (endptr != 0)
132 *endptr = (char *)(any ? s - 1 : nptr);
133 return (acc);
134 }
135