source: trunk/third/sendmail/libsm/strto.c @ 19204

/*
 * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
 *      All rights reserved.
 * Copyright (c) 1992
 *      The Regents of the University of California.  All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 */

#include <sm/gen.h>
SM_IDSTR(id, "@(#)$Id: strto.c,v 1.1.1.1 2003-04-08 15:06:42 zacheiss Exp $")

#include <sys/param.h>
#include <sys/types.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <sm/limits.h>
#include <sm/conf.h>
#include <sm/string.h>

/*
**  SM_STRTOLL --  Convert a string to a (signed) long long integer.
**
**  Ignores `locale' stuff.  Assumes that the upper and lower case
**  alphabets and digits are each contiguous.
**
**      Parameters:
**              nptr -- string containing number
**              endptr -- location of first invalid character
**              base -- numeric base that 'nptr' number is based in
**
**      Returns:
**              Failure: on underflow LLONG_MIN is returned; on overflow
**                      LLONG_MAX is returned and errno is set.
**                      When 'endptr' == '\0' then the entire string 'nptr'
**                      was valid.
**              Success: returns the converted number
*/

LONGLONG_T
sm_strtoll(nptr, endptr, base)
        const char *nptr;
        char **endptr;
        register int base;
{
        register bool neg;
        register const char *s;
        register LONGLONG_T acc, cutoff;
        register int c;
        register int 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 = (unsigned char) *s++;
        } while (isascii(c) && isspace(c));
        if (c == '-')
        {
                neg = true;
                c = *s++;
        }
        else
        {
                neg = false;
                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;

        /*
        **  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 long-long's is
        **  [-9223372036854775808..9223372036854775807] and the input base
        **  is 10, cutoff will be set to 922337203685477580 and cutlim to
        **  either 7 (!neg) or 8 (neg), meaning that if we have
        **  accumulated a value > 922337203685477580, 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 ? LLONG_MIN : LLONG_MAX;
        cutlim = cutoff % base;
        cutoff /= base;
        if (neg)
        {
                if (cutlim > 0)
                {
                        cutlim -= base;
                        cutoff += 1;
                }
                cutlim = -cutlim;
        }
        for (acc = 0, any = 0;; c = (unsigned char) *s++)
        {
                if (isascii(c) && isdigit(c))
                        c -= '0';
                else if (isascii(c) && isalpha(c))
                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
                else
                        break;
                if (c >= base)
                        break;
                if (any < 0)
                        continue;
                if (neg)
                {
                        if (acc < cutoff || (acc == cutoff && c > cutlim))
                        {
                                any = -1;
                                acc = LLONG_MIN;
                                errno = ERANGE;
                        }
                        else
                        {
                                any = 1;
                                acc *= base;
                                acc -= c;
                        }
                }
                else
                {
                        if (acc > cutoff || (acc == cutoff && c > cutlim))
                        {
                                any = -1;
                                acc = LLONG_MAX;
                                errno = ERANGE;
                        }
                        else
                        {
                                any = 1;
                                acc *= base;
                                acc += c;
                        }
                }
        }
        if (endptr != 0)
                *endptr = (char *) (any ? s - 1 : nptr);
        return acc;
}

/*
**  SM_STRTOULL --  Convert a string to an unsigned long long integer.
**
**  Ignores `locale' stuff.  Assumes that the upper and lower case
**  alphabets and digits are each contiguous.
**
**      Parameters:
**              nptr -- string containing (unsigned) number
**              endptr -- location of first invalid character
**              base -- numeric base that 'nptr' number is based in
**
**      Returns:
**              Failure: on overflow ULLONG_MAX is returned and errno is set.
**                      When 'endptr' == '\0' then the entire string 'nptr'
**                      was valid.
**              Success: returns the converted number
*/

ULONGLONG_T
sm_strtoull(nptr, endptr, base)
        const char *nptr;
        char **endptr;
        register int base;
{
        register const char *s;
        register ULONGLONG_T acc, cutoff;
        register int c;
        register bool neg;
        register int any, cutlim;

        /* See sm_strtoll for comments as to the logic used. */
        s = nptr;
        do
        {
                c = (unsigned char) *s++;
        } while (isascii(c) && isspace(c));
        neg = (c == '-');
        if (neg)
        {
                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 = ULLONG_MAX / (ULONGLONG_T)base;
        cutlim = ULLONG_MAX % (ULONGLONG_T)base;
        for (acc = 0, any = 0;; c = (unsigned char) *s++)
        {
                if (isascii(c) && isdigit(c))
                        c -= '0';
                else if (isascii(c) && isalpha(c))
                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
                else
                        break;
                if (c >= base)
                        break;
                if (any < 0)
                        continue;
                if (acc > cutoff || (acc == cutoff && c > cutlim))
                {
                        any = -1;
                        acc = ULLONG_MAX;
                        errno = ERANGE;
                }
                else
                {
                        any = 1;
                        acc *= (ULONGLONG_T)base;
                        acc += c;
                }
        }
        if (neg && any > 0)
                acc = -((LONGLONG_T) acc);
        if (endptr != 0)
                *endptr = (char *) (any ? s - 1 : nptr);
        return acc;
}