src/system/libroot/posix/stdlib/strtouq.c

   1 /*-
   2  * Copyright (c) 1992 The Regents of the University of California.
   3  * 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 #include <sys/types.h>
  35
  36 #include <ctype.h>
  37 #include <errno.h>
  38 //#include <limits.h>
  39 #include <stdlib.h>
  40
  41 #include <errno_private.h>
  42
  43
  44 #define UQUAD_MAX 0xffffffffffffffffULL
  45 /*
  46  * Convert a string to an unsigned quad integer.
  47  *
  48  * Ignores `locale' stuff.  Assumes that the upper and lower case
  49  * alphabets and digits are each contiguous.
  50  */
  51 uint64
  52 strtouq(nptr, endptr, base)
  53         const char *nptr;
  54         char **endptr;
  55         register int base;
  56 {
  57         register const char *s;
  58         register uint64 acc, cutoff;
  59         register int c;
  60         register int neg, any, cutlim;
  61
  62         /*
  63          * See strtoq for comments as to the logic used.
  64          */
  65         s = nptr;
  66         do {
  67                 c = (unsigned char) *s++;
  68         } while (isspace(c));
  69         if (c == '-') {
  70                 neg = 1;
  71                 c = *s++;
  72         } else {
  73                 neg = 0;
  74                 if (c == '+')
  75                         c = *s++;
  76         }
  77         if ((base == 0 || base == 16) &&
  78             c == '0' && (*s == 'x' || *s == 'X')) {
  79                 c = s[1];
  80                 s += 2;
  81                 base = 16;
  82         }
  83         if (base == 0)
  84                 base = c == '0' ? 8 : 10;
  85
  86         cutoff = UQUAD_MAX / (uint64)base;
  87         cutlim = UQUAD_MAX % (uint64)base;
  88         for (acc = 0, any = 0;; c = (unsigned char) *s++) {
  89                 if (isdigit(c))
  90                         c -= '0';
  91                 else if (isalpha(c))
  92                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
  93                 else
  94                         break;
  95                 if (c >= base)
  96                         break;
  97                 if (any < 0)
  98                         continue;
  99                 if (acc > cutoff || (acc == cutoff && c > cutlim)) {
 100                         any = -1;
 101                         acc = UQUAD_MAX;
 102                         __set_errno(ERANGE);
 103                 } else {
 104                         any = 1;
 105                         acc *= (uint64)base;
 106                         acc += c;
 107                 }
 108         }
 109         if (neg && any > 0)
 110                 acc = -acc;
 111         if (endptr != 0)
 112                 *endptr = (char *) (any ? s - 1 : nptr);
 113         return (acc);
 114 }