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

   1 /*
   2  * Copyright (c) 1990, 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
  35 #include <limits.h>
  36 #include <ctype.h>
  37 #include <errno.h>
  38 #include <stdlib.h>
  39
  40 #include <errno_private.h>
  41
  42
  43 /*
  44  * Convert a string to an unsigned long integer.
  45  *
  46  * Assumes that the upper and lower case
  47  * alphabets and digits are each contiguous.
  48  */
  49
  50 unsigned long
  51 strtoul(const char * __restrict nptr, char ** __restrict endptr, int base)
  52 {
  53         const char *s;
  54         unsigned long acc;
  55         char c;
  56         unsigned long cutoff;
  57         int neg, any, cutlim;
  58
  59         /*
  60          * See strtol for comments as to the logic used.
  61          */
  62         s = nptr;
  63         do {
  64                 c = *s++;
  65         } while (isspace((unsigned char)c));
  66         if (c == '-') {
  67                 neg = 1;
  68                 c = *s++;
  69         } else {
  70                 neg = 0;
  71                 if (c == '+')
  72                         c = *s++;
  73         }
  74         if ((base == 0 || base == 16) &&
  75             c == '0' && (*s == 'x' || *s == 'X')) {
  76                 c = s[1];
  77                 s += 2;
  78                 base = 16;
  79         }
  80         if (base == 0)
  81                 base = c == '0' ? 8 : 10;
  82         acc = any = 0;
  83         if (base < 2 || base > 36)
  84                 goto noconv;
  85
  86         cutoff = ULONG_MAX / base;
  87         cutlim = ULONG_MAX % base;
  88         for ( ; ; c = *s++) {
  89                 if (c >= '0' && c <= '9')
  90                         c -= '0';
  91                 else if (c >= 'A' && c <= 'Z')
  92                         c -= 'A' - 10;
  93                 else if (c >= 'a' && c <= 'z')
  94                         c -= 'a' - 10;
  95                 else
  96                         break;
  97                 if (c >= base)
  98                         break;
  99                 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 100                         any = -1;
 101                 else {
 102                         any = 1;
 103                         acc *= base;
 104                         acc += c;
 105                 }
 106         }
 107         if (any < 0) {
 108                 acc = ULONG_MAX;
 109                 __set_errno(ERANGE);
 110         } else if (!any) {
 111 noconv:
 112                 __set_errno(EINVAL);
 113         } else if (neg)
 114                 acc = -acc;
 115         if (endptr != NULL)
 116                 *endptr = (char *)(any ? s - 1 : nptr);
 117         return (acc);
 118 }
 119
 120
 121 unsigned long __strtoul_internal(const char *number, char **_end, int base, int group);
 122
 123 unsigned long
 124 __strtoul_internal(const char *number, char **_end, int base, int group)
 125 {
 126         // ToDo: group is currently not supported!
 127         (void)group;
 128
 129         return strtoul(number, _end, base);
 130 }
 131