1  /*
       2   * Copyright (c) 1990 Regents of the University of California.
       3   * 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. [rescinded 22 July 1999]
      14   * 4. Neither the name of the University nor the names of its contributors
      15   *    may be used to endorse or promote products derived from this software
      16   *    without specific prior written permission.
      17   *
      18   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
      19   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      20   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      21   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
      22   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      23   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      24   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      25   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      26   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      27   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      28   * SUCH DAMAGE.
      29   */
      30  
      31  #ifdef HAVE_CONFIG_H
      32  #include "config.h"
      33  #endif
      34  #ifdef HAVE_LIMITS_H
      35  #include <limits.h>
      36  #endif
      37  #ifdef HAVE_SYS_PARAM_H
      38  #include <sys/param.h>
      39  #endif
      40  #include <errno.h>
      41  #ifdef NEED_DECLARATION_ERRNO
      42  extern int errno;
      43  #endif
      44  #if 0
      45  #include <stdlib.h>
      46  #endif
      47  #include "ansidecl.h"
      48  #include "safe-ctype.h"
      49  
      50  #ifndef ULONG_MAX
      51  #define	ULONG_MAX	((unsigned long)(~0L))		/* 0xFFFFFFFF */
      52  #endif
      53  
      54  /*
      55   * Convert a string to an unsigned long integer.
      56   *
      57   * Ignores `locale' stuff.  Assumes that the upper and lower case
      58   * alphabets and digits are each contiguous.
      59   */
      60  unsigned long
      61  strtoul(const char *nptr, char **endptr, register int base)
      62  {
      63  	register const char *s = nptr;
      64  	register unsigned long acc;
      65  	register int c;
      66  	register unsigned long cutoff;
      67  	register int neg = 0, any, cutlim;
      68  
      69  	/*
      70  	 * See strtol for comments as to the logic used.
      71  	 */
      72  	do {
      73  		c = *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 = (unsigned long)ULONG_MAX / (unsigned long)base;
      89  	cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
      90  	for (acc = 0, any = 0;; c = *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  }