contrib/bind-9.3/lib/bind/bsd/strtoul.c

   1 #if defined(LIBC_SCCS) && !defined(lint)
   2 static const char sccsid[] = "@(#)strtoul.c     8.1 (Berkeley) 6/4/93";
   3 static const char rcsid[] = "$Id: strtoul.c,v 1.1.2.1 2003/06/27 03:51:35 marka Exp $";
   4 #endif /* LIBC_SCCS and not lint */
   5
   6 /*
   7  * Copyright (c) 1990, 1993
   8  *    The Regents of the University of California.  All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include "port_before.h"
  40
  41 #include <sys/types.h>
  42 #include <sys/param.h>
  43
  44 #include <ctype.h>
  45 #include <errno.h>
  46 #include <limits.h>
  47 #include <stdlib.h>
  48
  49 #include "port_after.h"
  50
  51 #ifndef NEED_STRTOUL
  52 int __strtoul_unneeded__;
  53 #else
  54
  55 /*
  56  * Convert a string to an unsigned long integer.
  57  *
  58  * Ignores `locale' stuff.  Assumes that the upper and lower case
  59  * alphabets and digits are each contiguous.
  60  */
  61 u_long
  62 strtoul(const char *nptr, char **endptr, int base) {
  63         const char *s = nptr;
  64         u_long acc, cutoff;
  65         int neg, c, any, cutlim;
  66
  67         neg = 0;
  68
  69         /*
  70          * See strtol for comments as to the logic used.
  71          */
  72         do {
  73                 c = *(unsigned char *)s++;
  74         } while (isspace(c));
  75         if (c == '-') {
  76                 neg = 1;
  77                 c = *s++;
  78         } else if (c == '+')
  79                 c = *s++;
  80         if ((base == 0 || base == 16) &&
  81             c == '0' && (*s == 'x' || *s == 'X')) {
  82                 c = s[1];
  83                 s += 2;
  84                 base = 16;
  85         }
  86         if (base == 0)
  87                 base = c == '0' ? 8 : 10;
  88         cutoff = (u_long)ULONG_MAX / (u_long)base;
  89         cutlim = (u_long)ULONG_MAX % (u_long)base;
  90         for (acc = 0, any = 0;; c = *(unsigned char*)s++) {
  91                 if (isdigit(c))
  92                         c -= '0';
  93                 else if (isalpha(c))
  94                         c -= isupper(c) ? 'A' - 10 : '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                 errno = ERANGE;
 110         } else if (neg)
 111                 acc = -acc;
 112         if (endptr != 0)
 113                 *endptr = (char *)(any ? s - 1 : nptr);
 114         return (acc);
 115 }
 116
 117 #endif /*NEED_STRTOUL*/