/*

 * 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.

 */

#include <net-snmp/net-snmp-config.h>

#if defined(LIBC_SCCS) && !defined(lint)

static char     sccsid[] = "@(#)strtoul.c   8.1 (Berkeley) 6/4/93";

#endif                          /* LIBC_SCCS and not lint */

#if HAVE_LIMITS_H

#include <limits.h>

#endif

#include <ctype.h>

#include <errno.h>

#if HAVE_STDLIB_H

#include <stdlib.h>

#endif

/*

 * 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, int base)

{

    const char     *s = nptr;

    unsigned long   acc;

    unsigned char   c;

    unsigned long   cutoff;

    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 (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 != 0)

        *endptr = (char *) (any ? s - 1 : nptr);

    return (acc);

}