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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)strtol.c 8.1 (Berkeley) 6/4/93
36 * Convert a string to a long integer.
38 * Ignores `locale' stuff. Assumes that the upper and lower case
39 * alphabets and digits are each contiguous.
42 strtol(const char *nptr
, char **endptr
, int base
)
48 int neg
= 0, any
, cutlim
;
50 /* Be sensible about NULL strings */
56 * Skip white space and pick up leading +/- sign if any.
57 * If base is 0, allow 0x for hex and 0 for octal, else
58 * assume decimal; if base is already 16, allow 0x.
68 if ((base
== 0 || base
== 16) &&
69 c
== '0' && (*s
== 'x' || *s
== 'X')) {
75 base
= c
== '0' ? 8 : 10;
78 * Compute the cutoff value between legal numbers and illegal
79 * numbers. That is the largest legal value, divided by the
80 * base. An input number that is greater than this value, if
81 * followed by a legal input character, is too big. One that
82 * is equal to this value may be valid or not; the limit
83 * between valid and invalid numbers is then based on the last
84 * digit. For instance, if the range for longs is
85 * [-2147483648..2147483647] and the input base is 10,
86 * cutoff will be set to 214748364 and cutlim to either
87 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
88 * a value > 214748364, or equal but the next digit is > 7 (or 8),
89 * the number is too big, and we will return a range error.
91 * Set any if any `digits' consumed; make it negative to indicate
94 cutoff
= neg
? -(unsigned long)LONG_MIN
: LONG_MAX
;
95 cutlim
= cutoff
% (unsigned long)base
;
96 cutoff
/= (unsigned long)base
;
97 for (acc
= 0, any
= 0;; c
= *s
++) {
103 c
-= isupper(c
) ? 'A' - 10 : 'a' - 10;
108 if (any
< 0 || acc
> cutoff
|| (acc
== cutoff
&& c
> cutlim
))
117 acc
= neg
? LONG_MIN
: LONG_MAX
;
122 *endptr
= (char *)(any
? s
- 1 : nptr
);