2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
42 * Convert a string to a long integer.
44 * Ignores `locale' stuff. Assumes that the upper and lower case
45 * alphabets and digits are each contiguous.
48 strtol(nptr, endptr, base)
53 register const char *s;
54 register unsigned long acc;
55 register unsigned char c;
56 register unsigned long cutoff;
57 register int neg = 0, any, cutlim;
59 /* Be sensible about NULL strings */
65 * Skip white space and pick up leading +/- sign if any.
66 * If base is 0, allow 0x for hex and 0 for octal, else
67 * assume decimal; if base is already 16, allow 0x.
77 if ((base == 0 || base == 16) &&
78 c == '0' && (*s == 'x' || *s == 'X')) {
84 base = c == '0' ? 8 : 10;
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 longs is
94 * [-2147483648..2147483647] and the input base is 10,
95 * cutoff will be set to 214748364 and cutlim to either
96 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
97 * a value > 214748364, or equal but the next digit is > 7 (or 8),
98 * the number is too big, and we will return a range error.
100 * Set any if any `digits' consumed; make it negative to indicate
103 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
104 cutlim = cutoff % (unsigned long)base;
105 cutoff /= (unsigned long)base;
106 for (acc = 0, any = 0;; c = *s++) {
112 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
117 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
126 acc = neg ? LONG_MIN : LONG_MAX;
131 *endptr = (char *)(any ? s - 1 : nptr);