freebsd-dev/contrib/bind9/lib/lwres/strtoul.c
2005-12-29 04:22:58 +00:00

136 lines
4.3 KiB
C

/*
* Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 2003 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*! \file */
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
/* $Id: strtoul.c,v 1.2.4.1 2005/06/08 02:08:31 marka Exp $ */
#include <config.h>
#include <limits.h>
#include <ctype.h>
#include <errno.h>
#include <lwres/stdlib.h>
#define DE_CONST(konst, var) \
do { \
union { const void *k; void *v; } _u; \
_u.k = konst; \
var = _u.v; \
} while (0)
/*!
* Convert a string to an unsigned long integer.
*
* Ignores `locale' stuff. Assumes that the upper and lower case
* alphabets and digits are each contiguous.
*/
unsigned long
lwres_strtoul(const char *nptr, char **endptr, int base) {
const char *s = nptr;
unsigned long acc;
unsigned char c;
unsigned long cutoff;
int neg = 0, any, cutlim;
/*
* See strtol for comments as to the logic used.
*/
do {
c = *s++;
} while (isspace(c));
if (c == '-') {
neg = 1;
c = *s++;
} else if (c == '+')
c = *s++;
if ((base == 0 || base == 16) &&
c == '0' && (*s == 'x' || *s == 'X')) {
c = s[1];
s += 2;
base = 16;
}
if (base == 0)
base = c == '0' ? 8 : 10;
cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
for (acc = 0, any = 0;; c = *s++) {
if (!isascii(c))
break;
if (isdigit(c))
c -= '0';
else if (isalpha(c))
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
else
break;
if (c >= base)
break;
if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
any = -1;
else {
any = 1;
acc *= base;
acc += c;
}
}
if (any < 0) {
acc = ULONG_MAX;
errno = ERANGE;
} else if (neg)
acc = -acc;
if (endptr != 0)
DE_CONST(any ? s - 1 : nptr, *endptr);
return (acc);
}