/* $NetBSD: strtol.c,v 1.15 1999/09/20 04:39:42 lukem Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: strtol.c,v 1.15 1999/09/20 04:39:42 lukem Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include
#include
#include
#include
#include
/*
* Convert a string to a long integer.
*
* Ignores `locale' stuff. Assumes that the upper and lower case
* alphabets and digits are each contiguous.
*/
long
strtol(nptr, endptr, base)
const char *nptr;
char **endptr;
int base;
{
const char *s;
long acc, cutoff;
int c;
int neg, any, cutlim;
_DIAGASSERT(nptr != NULL);
/* endptr may be NULL */
/*
* Skip white space and pick up leading +/- sign if any.
* If base is 0, allow 0x for hex and 0 for octal, else
* assume decimal; if base is already 16, allow 0x.
*/
s = nptr;
do {
c = (unsigned char) *s++;
} while (isspace(c));
if (c == '-') {
neg = 1;
c = *s++;
} else {
neg = 0;
if (c == '+')
c = *s++;
}
if ((base == 0 || base == 16) &&
c == '0' && (*s == 'x' || *s == 'X')) {
c = s[1];
s += 2;
base = 16;
}
if (base == 0)
base = c == '0' ? 8 : 10;
/*
* Compute the cutoff value between legal numbers and illegal
* numbers. That is the largest legal value, divided by the
* base. An input number that is greater than this value, if
* followed by a legal input character, is too big. One that
* is equal to this value may be valid or not; the limit
* between valid and invalid numbers is then based on the last
* digit. For instance, if the range for longs is
* [-2147483648..2147483647] and the input base is 10,
* cutoff will be set to 214748364 and cutlim to either
* 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
* a value > 214748364, or equal but the next digit is > 7 (or 8),
* the number is too big, and we will return a range error.
*
* Set any if any `digits' consumed; make it negative to indicate
* overflow.
*/
cutoff = neg ? LONG_MIN : LONG_MAX;
cutlim = (int)(cutoff % base);
cutoff /= base;
if (neg) {
if (cutlim > 0) {
cutlim -= base;
cutoff += 1;
}
cutlim = -cutlim;
}
for (acc = 0, any = 0;; c = (unsigned char) *s++) {
if (isdigit(c))
c -= '0';
else if (isalpha(c))
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
else
break;
if (c >= base)
break;
if (any < 0)
continue;
if (neg) {
if (acc < cutoff || (acc == cutoff && c > cutlim)) {
any = -1;
acc = LONG_MIN;
errno = ERANGE;
} else {
any = 1;
acc *= base;
acc -= c;
}
} else {
if (acc > cutoff || (acc == cutoff && c > cutlim)) {
any = -1;
acc = LONG_MAX;
errno = ERANGE;
} else {
any = 1;
acc *= base;
acc += c;
}
}
}
if (endptr != 0)
/* LINTED interface specification */
*endptr = (char *)(any ? s - 1 : nptr);
return (acc);
}