stdlib/strtoull.c

   1 /*-
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)strtouq.c   8.1 (Berkeley) 6/4/93";
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 #if defined(LIBC_SCCS) && !defined(lint)
  39 static const char rcsid[] =
  40   "$FreeBSD: src/lib/libc/stdlib/strtoull.c,v 1.5.2.1 2001/03/02 09:45:20 obrien Exp $";
  41 #endif
  42
  43 #include <sys/types.h>
  44
  45 #include <limits.h>
  46 #include <errno.h>
  47 #include <ctype.h>
  48 #include <stdlib.h>
  49
  50 /*
  51  * Convert a string to an unsigned long long integer.
  52  *
  53  * Ignores `locale' stuff.  Assumes that the upper and lower case
  54  * alphabets and digits are each contiguous.
  55  */
  56 unsigned long long
  57 strtoull(nptr, endptr, base)
  58         const char *nptr;
  59         char **endptr;
  60         register int base;
  61 {
  62         register const char *s = nptr;
  63         register unsigned long long acc;
  64         register unsigned char c;
  65         register unsigned long long qbase, cutoff;
  66         register int neg, any, cutlim;
  67
  68         /*
  69          * See strtoq for comments as to the logic used.
  70          */
  71         s = nptr;
  72         do {
  73                 c = *s++;
  74         } while (isspace(c));
  75         if (c == '-') {
  76                 neg = 1;
  77                 c = *s++;
  78         } else {
  79                 neg = 0;
  80                 if (c == '+')
  81                         c = *s++;
  82         }
  83         if ((base == 0 || base == 16) &&
  84             c == '0' && (*s == 'x' || *s == 'X')) {
  85                 c = s[1];
  86                 s += 2;
  87                 base = 16;
  88         }
  89         if (base == 0)
  90                 base = c == '0' ? 8 : 10;
  91         qbase = (unsigned)base;
  92         cutoff = (unsigned long long)ULLONG_MAX / qbase;
  93         cutlim = (unsigned long long)ULLONG_MAX % qbase;
  94         for (acc = 0, any = 0;; c = *s++) {
  95                 if (!isascii(c))
  96                         break;
  97                 if (isdigit(c))
  98                         c -= '0';
  99                 else if (isalpha(c))
 100                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 101                 else
 102                         break;
 103                 if (c >= base)
 104                         break;
 105                 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 106                         any = -1;
 107                 else {
 108                         any = 1;
 109                         acc *= qbase;
 110                         acc += c;
 111                 }
 112         }
 113         if (any < 0) {
 114                 acc = ULLONG_MAX;
 115                 errno = ERANGE;
 116         } else if (neg)
 117                 acc = -acc;
 118         if (endptr != 0)
 119                 *endptr = (char *)(any ? s - 1 : nptr);
 120         return (acc);
 121 }