Files
vxWorks/libc/stdlib/strtoul.c
2025-08-20 18:25:46 +08:00

201 lines
6.9 KiB
C

/* strtoul.c - strtoul file for stdlib */
/* Copyright 1992-1993 Wind River Systems, Inc. */
/*
modification history
--------------------
01d,08feb93,jdi documentation cleanup for 5.1.
01c,21sep92,smb tweaks for mg
01b,20sep92,smb documentation additions.
01a,10jul92,smb documented.
*/
/*
DESCRIPTION
* Copyright (c) 1990 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.
INCLUDE FILES: stdlib.h, limits.h, ctype.h, errno.h
SEE ALSO: American National Standard X3.159-1989
NOMANUAL
*/
#include "vxWorks.h"
#include "limits.h"
#include "ctype.h"
#include "errno.h"
#include "stdlib.h"
/*****************************************************************************
*
* strtoul - convert a string to an unsigned long integer (ANSI)
*
* This routine converts the initial portion of a string <nptr> to
* `unsigned long int' representation. First, it decomposes the input
* string into three parts: an initial, possibly empty, sequence of
* white-space characters (as specified by isspace()); a subject sequence
* resembling an unsigned integer represented in some radix determined by
* the value <base>; and a final string of one or more unrecognized
* characters, including the terminating null character of the input string.
* Then, it attempts to convert the subject sequence to an unsigned integer,
* and returns the result.
*
* If the value of <base> is zero, the expected form of the subject sequence
* is that of an integer constant, optionally preceded by a plus or minus
* sign, but not including an integer suffix. If the value of <base> is
* between 2 and 36, the expected form of the subject sequence is a sequence
* of letters and digits representing an integer with the radix specified by
* letters from a (or A) through z (or Z) which are ascribed the values 10 to
* 35; only letters whose ascribed values are less than <base> are
* premitted. If the value of <base> is 16, the characters 0x or 0X may
* optionally precede the sequence of letters and digits, following the sign
* if present.
*
* The subject sequence is defined as the longest initial subsequence of the
* input string, starting with the first non-white-space character, that is
* of the expected form. The subject sequence contains no characters if the
* input string is empty or consists entirely of white space, or if the first
* non-white-space character is other than a sign or a permissible letter or
* digit.
*
* If the subject sequence has the expected form and the value of <base> is
* zero, the sequence of characters starting with the first digit is
* interpreted as an integer constant. If the subject sequence has the
* expected form and the value of <base> is between 2 and 36, it is used as
* the <base> for conversion, ascribing to each letter its value as given
* above. If the subject sequence begins with a minus sign, the value
* resulting from the conversion is negated. A pointer to the final string
* is stored in the object pointed to by <endptr>, provided that <endptr> is
* not a null pointer.
*
* In other than the "C" locale, additional implementation-defined subject
* sequence forms may be accepted. VxWorks supports only the "C" locale;
* it assumes that the upper- and lower-case alphabets and digits are
* each contiguous.
*
* If the subject sequence is empty or does not have the expected form, no
* conversion is performed; the value of <nptr> is stored in the object
* pointed to by <endptr>, provided that <endptr> is not a null pointer.
*
* INCLUDE FILES: stdlib.h
*
* RETURNS:
* The converted value, if any. If no conversion could be performed it
* returns zero. If the correct value is outside the range of representable
* values, it returns ULONG_MAX, and stores the value of the macro ERANGE in
* <errno>.
*/
ulong_t strtoul
(
const char * nptr, /* string to convert */
char ** endptr, /* ptr to final string */
FAST int base /* radix */
)
{
FAST const char *s = nptr;
FAST ulong_t acc;
FAST int c;
FAST ulong_t cutoff;
FAST int neg = 0;
FAST int any;
FAST int 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 = (ulong_t)ULONG_MAX / (ulong_t)base;
cutlim = (ulong_t)ULONG_MAX % (ulong_t)base;
for (acc = 0, any = 0;; c = *s++)
{
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)
*endptr = (any ? CHAR_FROM_CONST (s - 1) : CHAR_FROM_CONST (nptr));
return (acc);
}