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   * 4. 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  #if defined(LIBC_SCCS) && !defined(lint)
 31  static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
 32  #endif /* LIBC_SCCS and not lint */
 33  #include <sys/cdefs.h>
 34  __FBSDID("$FreeBSD: src/lib/libc/stdlib/strtoul.c,v 1.19 2007/01/09 00:28:10 imp Exp $");
 35  
 36  #include "xlocale_private.h"
 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   * Assumes that the upper and lower case
 47   * alphabets and digits are each contiguous.
 48   */
 49  unsigned long
 50  strtoul_l(const char * __restrict nptr, char ** __restrict endptr, int base,
 51      locale_t loc)
 52  {
 53  	const char *s;
 54  	unsigned long acc;
 55  	char c;
 56  	unsigned long cutoff;
 57  	int neg, any, cutlim;
 58  
 59  	NORMALIZE_LOCALE(loc);
 60  	/*
 61  	 * See strtol for comments as to the logic used.
 62  	 */
 63  	s = nptr;
 64  	do {
 65  		c = *s++;
 66  	} while (isspace_l((unsigned char)c, loc));
 67  	if (c == '-') {
 68  		neg = 1;
 69  		c = *s++;
 70  	} else {
 71  		neg = 0;
 72  		if (c == '+')
 73  			c = *s++;
 74  	}
 75  	if ((base == 0 || base == 16) &&
 76  	    c == '0' && (*s == 'x' || *s == 'X') &&
 77  	    ((s[1] >= '0' && s[1] <= '9') ||
 78  	    (s[1] >= 'A' && s[1] <= 'F') ||
 79  	    (s[1] >= 'a' && s[1] <= 'f'))) {
 80  		c = s[1];
 81  		s += 2;
 82  		base = 16;
 83  	}
 84  	if (base == 0)
 85  		base = c == '0' ? 8 : 10;
 86  	acc = any = 0;
 87  	if (base < 2 || base > 36)
 88  		goto noconv;
 89  
 90  	cutoff = ULONG_MAX / base;
 91  	cutlim = ULONG_MAX % base;
 92  	for ( ; ; c = *s++) {
 93  		if (c >= '0' && c <= '9')
 94  			c -= '0';
 95  		else if (c >= 'A' && c <= 'Z')
 96  			c -= 'A' - 10;
 97  		else if (c >= 'a' && c <= 'z')
 98  			c -= 'a' - 10;
 99  		else
100  			break;
101  		if (c >= base)
102  			break;
103  		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
104  			any = -1;
105  		else {
106  			any = 1;
107  			acc *= base;
108  			acc += c;
109  		}
110  	}
111  	if (any < 0) {
112  		acc = ULONG_MAX;
113  		errno = ERANGE;
114  	} else if (!any) {
115  noconv:
116  		errno = EINVAL;
117  	} else if (neg)
118  		acc = -acc;
119  	if (endptr != NULL)
120  		*endptr = (char *)(any ? s - 1 : nptr);
121  	return (acc);
122  }
123  
124  unsigned long
125  strtoul(const char * __restrict nptr, char ** __restrict endptr, int base)
126  {
127  	return strtoul_l(nptr, endptr, base, __current_locale());
128  }