usr/lib/libc/stdlib/strtoul.c

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This source file includes following definitions.
strtoul
   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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29 
  30 #include <limits.h>
  31 #include <ctype.h>
  32 #include <errno.h>
  33 #include <stdlib.h>
  34 
  35 /*
  36  * Convert a string to an unsigned long integer.
  37  *
  38  * Ignores `locale' stuff.  Assumes that the upper and lower case
  39  * alphabets and digits are each contiguous.
  40  */
  41 unsigned long
  42 strtoul(nptr, endptr, base)
  43         const char *nptr;
  44         char **endptr;
  45         register int base;
  46 {
  47         const char *s;
  48         unsigned long acc, cutoff;
  49         int c;
  50         int neg, any, cutlim;
  51 
  52         /*
  53          * See strtol for comments as to the logic used.
  54          */
  55         s = nptr;
  56         do {
  57                 c = (unsigned char) *s++;
  58         } while (isspace(c));
  59         if (c == '-') {
  60                 neg = 1;
  61                 c = *s++;
  62         } else {
  63                 neg = 0;
  64                 if (c == '+')
  65                         c = *s++;
  66         }
  67         if ((base == 0 || base == 16) &&
  68             c == '0' && (*s == 'x' || *s == 'X')) {
  69                 c = s[1];
  70                 s += 2;
  71                 base = 16;
  72         }
  73         if (base == 0)
  74                 base = c == '0' ? 8 : 10;
  75 
  76         cutoff = ULONG_MAX / (unsigned long)base;
  77         cutlim = (int)(ULONG_MAX % (unsigned long)base);
  78         for (acc = 0, any = 0;; c = (unsigned char) *s++) {
  79                 if (isdigit(c))
  80                         c -= '0';
  81                 else if (isalpha(c))
  82                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
  83                 else
  84                         break;
  85                 if (c >= base)
  86                         break;
  87                 if (any < 0)
  88                         continue;
  89                 if (acc > cutoff || (acc == cutoff && c > cutlim)) {
  90                         any = -1;
  91                         acc = ULONG_MAX;
  92                         errno = ERANGE;
  93                 } else {
  94                         any = 1;
  95                         acc *= (unsigned long)base;
  96                         acc += c;
  97                 }
  98         }
  99         if (neg && any > 0)
 100                 acc = -acc;
 101         if (endptr != 0)
 102                 /* LINTED interface specification */
 103                 *endptr = (char *)(any ? s - 1 : nptr);
 104         return (acc);
 105 }
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root/usr/lib/libc/stdlib/strtoul.c

DEFINITIONS
