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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 /*	Copyright (c) 1988 AT&T	*/
     28 /*	  All Rights Reserved  	*/
     29 
     30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     31 
     32 #if !defined(_BOOT) && !defined(_KMDB)
     33 #include "lint.h"
     34 #endif /* !_BOOT && !_KMDB */
     35 #include <errno.h>
     36 #include <ctype.h>
     37 #include <limits.h>
     38 #include <stdlib.h>
     39 #include <sys/types.h>
     40 
     41 #define	DIGIT(x)	\
     42 	(isdigit(x) ? (x) - '0' : islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')
     43 
     44 #define	MBASE	('z' - 'a' + 1 + 10)
     45 
     46 /*
     47  * The following macro is a local version of isalnum() which limits
     48  * alphabetic characters to the ranges a-z and A-Z; locale dependent
     49  * characters will not return 1. The members of a-z and A-Z are
     50  * assumed to be in ascending order and contiguous
     51  */
     52 #define	lisalnum(x)	\
     53 	(isdigit(x) || ((x) >= 'a' && (x) <= 'z') || ((x) >= 'A' && (x) <= 'Z'))
     54 
     55 unsigned long
     56 strtoul(const char *str, char **nptr, int base)
     57 {
     58 	unsigned long val;
     59 	int c;
     60 	int xx;
     61 	unsigned long	multmax;
     62 	int neg = 0;
     63 	const char **ptr = (const char **)nptr;
     64 	const unsigned char	*ustr = (const unsigned char *)str;
     65 
     66 	if (ptr != (const char **)0)
     67 		*ptr = (char *)ustr; /* in case no number is formed */
     68 	if (base < 0 || base > MBASE || base == 1) {
     69 		errno = EINVAL;
     70 		return (0); /* base is invalid -- should be a fatal error */
     71 	}
     72 	if (!isalnum(c = *ustr)) {
     73 		while (isspace(c))
     74 			c = *++ustr;
     75 		switch (c) {
     76 		case '-':
     77 			neg++;
     78 			/* FALLTHROUGH */
     79 		case '+':
     80 			c = *++ustr;
     81 		}
     82 	}
     83 	if (base == 0)
     84 		if (c != '0')
     85 			base = 10;
     86 		else if (ustr[1] == 'x' || ustr[1] == 'X')
     87 			base = 16;
     88 		else
     89 			base = 8;
     90 	/*
     91 	 * for any base > 10, the digits incrementally following
     92 	 *	9 are assumed to be "abc...z" or "ABC...Z"
     93 	 */
     94 	if (!lisalnum(c) || (xx = DIGIT(c)) >= base)
     95 		return (0); /* no number formed */
     96 	if (base == 16 && c == '0' && (ustr[1] == 'x' || ustr[1] == 'X') &&
     97 	    isxdigit(ustr[2]))
     98 		c = *(ustr += 2); /* skip over leading "0x" or "0X" */
     99 
    100 	multmax = ULONG_MAX / (unsigned long)base;
    101 	val = DIGIT(c);
    102 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; ) {
    103 		if (val > multmax)
    104 			goto overflow;
    105 		val *= base;
    106 		if (ULONG_MAX - val < xx)
    107 			goto overflow;
    108 		val += xx;
    109 		c = *++ustr;
    110 	}
    111 	if (ptr != (const char **)0)
    112 		*ptr = (char *)ustr;
    113 	return (neg ? -val : val);
    114 
    115 overflow:
    116 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; (c = *++ustr))
    117 		;
    118 	if (ptr != (const char **)0)
    119 		*ptr = (char *)ustr;
    120 	errno = ERANGE;
    121 	return (ULONG_MAX);
    122 }
    123