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/*
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 * Copyright (c) 1990, 1993
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 *        The Regents of the University of California.  All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#include <limits.h>
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#include <ctype.h>
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#include <errno.h>
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#include <stdlib.h>
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/*
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 * Convert a string to an unsigned long integer.
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 *
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 * Ignores `locale' stuff.  Assumes that the upper and lower case
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 * alphabets and digits are each contiguous.
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 */
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unsigned long
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strtoul(nptr, endptr, base)
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        const char *nptr;
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        char **endptr;
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        register int base;
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{
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        const char *s;
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        unsigned long acc, cutoff;
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        int c;
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        int neg, any, cutlim;
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        /*
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         * See strtol for comments as to the logic used.
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         */
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        s = nptr;
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        do {
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                c = (unsigned char) *s++;
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        } while (isspace(c));
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        if (c == '-') {
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                neg = 1;
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                c = *s++;
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        } else {
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                neg = 0;
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                if (c == '+')
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                        c = *s++;
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        }
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        if ((base == 0 || base == 16) &&
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            c == '0' && (*s == 'x' || *s == 'X')) {
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                c = s[1];
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                s += 2;
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                base = 16;
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        }
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        if (base == 0)
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                base = c == '0' ? 8 : 10;
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        cutoff = ULONG_MAX / (unsigned long)base;
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        cutlim = (int)(ULONG_MAX % (unsigned long)base);
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        for (acc = 0, any = 0;; c = (unsigned char) *s++) {
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                if (isdigit(c))
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                        c -= '0';
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                else if (isalpha(c))
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                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
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                else
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                        break;
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                if (c >= base)
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                        break;
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                if (any < 0)
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                        continue;
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                if (acc > cutoff || (acc == cutoff && c > cutlim)) {
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                        any = -1;
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                        acc = ULONG_MAX;
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                        errno = ERANGE;
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                } else {
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                        any = 1;
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                        acc *= (unsigned long)base;
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                        acc += c;
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                }
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        }
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        if (neg && any > 0)
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                acc = -acc;
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        if (endptr != 0)
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                /* LINTED interface specification */
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                *endptr = (char *)(any ? s - 1 : nptr);
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        return (acc);
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}