/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Copyright (c) 2011 The FreeBSD Foundation
* All rights reserved.
* Portions of this software were developed by David Chisnall
* under sponsorship from the FreeBSD Foundation.
*
* 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. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <limits.h>
#include <ctype.h>
#include <stdlib.h>
/*
* Convert a string to a long integer.
*
* Assumes that the upper and lower case
* alphabets and digits are each contiguous.
*/
long
strtol(const char *__restrict nptr, char **__restrict endptr, int base)
{
const char *s;
unsigned long acc;
char c;
unsigned long cutoff;
int neg, any, cutlim;
/*
* 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 = *s++;
} while(isspace((unsigned char)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') &&
((s[1] >= '0' && s[1] <= '9') ||
(s[1] >= 'A' && s[1] <= 'F') ||
(s[1] >= 'a' && s[1] <= 'f'))) {
c = s[1];
s += 2;
base = 16;
}
if(base == 0) {
base = c == '0' ? 8 : 10;
}
acc = any = 0;
if(base < 2 || base > 36) {
goto noconv;
}
/*
* 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 ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX
: LONG_MAX;
cutlim = cutoff % base;
cutoff /= base;
for(; ; c = *s++) {
if(c >= '0' && c <= '9') {
c -= '0';
} else if(c >= 'A' && c <= 'Z') {
c -= 'A' - 10;
} else if(c >= 'a' && c <= 'z') {
c -= 'a' - 10;
} else {
break;
}
if(c >= base) {
break;
}
if(any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) {
any = -1;
} else {
any = 1;
acc *= base;
acc += c;
}
}
if(any < 0) {
acc = neg ? LONG_MIN : LONG_MAX;
} else if(!any) {
} else if(neg) {
acc = -acc;
}
noconv:
if(endptr != NULL) {
*endptr = (char *)(any ? s - 1 : nptr);
}
return (acc);
}
