blob: 31e930ef53b6c20636dfdd12c660e4e32c10b41c [file] [log] [blame]
/* SPDX-License-Identifier: BSD-3-Clause */
/*
* Copyright (c) 1990 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. 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 <limits.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
/*
* Convert a string to an unsigned long integer.
*
* Ignores `locale' stuff. Assumes that the upper and lower case
* alphabets and digits are each contiguous.
*/
unsigned long strtoul(const char *nptr, char **endptr, register int base)
{
register const char *s = nptr;
register unsigned long acc;
register int c;
register unsigned long cutoff;
register int neg = 0, any, cutlim;
/*
* See strtol for comments as to the logic used.
*/
do {
c = *s++;
} while (isspace((unsigned char)c) != 0);
if (c == '-') {
neg = 1;
c = *s++;
} else 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;
}
cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
for (acc = 0, any = 0;; c = *s++) {
if (isdigit((unsigned char)c) != 0) {
c -= '0';
} else if (isalpha((unsigned char)c) != 0) {
c -= isupper((unsigned char)c) != 0 ? 'A' - 10 : '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 = ULONG_MAX;
errno = ERANGE;
} else if (neg) {
acc = -acc;
}
if (endptr != NULL) {
*endptr = (char *)(any ? s - 1 : nptr);
}
return acc;
}