/
strtoul.c
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strtoul.c
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/*
* src/port/strtoul.c
*
*
* 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. 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[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include "c.h"
#include <limits.h>
#include <ctype.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(nptr, endptr, base)
const char *nptr;
char **endptr;
register int base;
{
register const char *s = nptr;
register unsigned long acc;
register unsigned char 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(c));
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 (!isascii(c))
break;
if (isdigit(c))
c -= '0';
else if (isalpha(c))
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
else
break;
if ((int) c >= base)
break;
if (any < 0 || acc > cutoff || (acc == cutoff && (int) 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 != 0)
*endptr = (char *) (any ? s - 1 : nptr);
return acc;
}