2.11BSD#431 - /usr/src/lib/libc/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: #if defined(LIBC_SCCS) && !defined(lint)
  35: static char sccsid[] = "@(#)strtoul.c	8.1.1 (2.11BSD) 1996/1/11";
  36: #endif /* LIBC_SCCS and not lint */
  37: 
  38: #include <limits.h>
  39: #include <ctype.h>
  40: #include <errno.h>
  41: #include <stdlib.h>
  42: 
  43: /*
  44:  * Convert a string to an unsigned long integer.
  45:  *
  46:  * Ignores `locale' stuff.  Assumes that the upper and lower case
  47:  * alphabets and digits are each contiguous.
  48:  */
  49: unsigned long
  50: strtoul(nptr, endptr, base)
  51:     char *nptr;
  52:     char **endptr;
  53:     register int base;
  54: {
  55:     register char *s = nptr;
  56:     register unsigned long acc;
  57:     register int c;
  58:     register unsigned long cutoff;
  59:     register int neg = 0, any, cutlim;
  60: 
  61:     /*
  62: 	 * See strtol for comments as to the logic used.
  63: 	 */
  64:     do {
  65:         c = *s++;
  66:     } while (isspace(c));
  67:     if (c == '-') {
  68:         neg = 1;
  69:         c = *s++;
  70:     } else if (c == '+')
  71:         c = *s++;
  72:     if ((base == 0 || base == 16) &&
  73:         c == '0' && (*s == 'x' || *s == 'X')) {
  74:         c = s[1];
  75:         s += 2;
  76:         base = 16;
  77:     }
  78:     if (base == 0)
  79:         base = c == '0' ? 8 : 10;
  80:     cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
  81:     cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
  82:     for (acc = 0, any = 0;; c = *s++) {
  83:         if (isdigit(c))
  84:             c -= '0';
  85:         else if (isalpha(c))
  86:             c -= isupper(c) ? 'A' - 10 : 'a' - 10;
  87:         else
  88:             break;
  89:         if (c >= base)
  90:             break;
  91:         if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
  92:             any = -1;
  93:         else {
  94:             any = 1;
  95:             acc *= base;
  96:             acc += c;
  97:         }
  98:     }
  99:     if (any < 0) {
 100:         acc = ULONG_MAX;
 101:         errno = ERANGE;
 102:     } else if (neg)
 103:         acc = -acc;
 104:     if (endptr != 0)
 105:         *endptr = (char *)(any ? s - 1 : nptr);
 106:     return (acc);
 107: }

Defined functions

Defined variables