130 lines
3.6 KiB
C
130 lines
3.6 KiB
C
/****************************************************************************
|
|
* libs/libc/stdlib/lib_strtoul.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
|
|
#include "libc.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: strtoul
|
|
*
|
|
* Description:
|
|
* The strtoul() function converts the initial part of the string in
|
|
* nptr to a long unsigned integer value according to the given base, which
|
|
* must be between 2 and 36 inclusive, or be the special value 0.
|
|
*
|
|
* Returned Value:
|
|
* - The converted value, if the base and number are valid
|
|
* - 0 if an error occurs, and set errno to:
|
|
* * EINVAL if base < 2 or base > 36
|
|
* - ULONG_MAX if an overflow occurs, and set errno to:
|
|
* * ERANGE if the number cannot be represented using unsigned long
|
|
*
|
|
****************************************************************************/
|
|
|
|
unsigned long strtoul(FAR const char *nptr, FAR char **endptr, int base)
|
|
{
|
|
unsigned long accum = 0;
|
|
unsigned long limit;
|
|
int value;
|
|
int last_digit;
|
|
char sign = 0;
|
|
|
|
if (nptr)
|
|
{
|
|
/* Skip leading spaces */
|
|
|
|
lib_skipspace(&nptr);
|
|
|
|
/* Check for leading + or - already done for strtol */
|
|
|
|
if (*nptr == '-' || *nptr == '+')
|
|
{
|
|
sign = *nptr;
|
|
nptr++;
|
|
}
|
|
|
|
/* Check for unspecified or incorrect base */
|
|
|
|
base = lib_checkbase(base, &nptr);
|
|
|
|
if (base < 0)
|
|
{
|
|
set_errno(EINVAL);
|
|
accum = 0;
|
|
}
|
|
else
|
|
{
|
|
limit = ULONG_MAX / base;
|
|
last_digit = ULONG_MAX % base;
|
|
|
|
/* Accumulate each "digit" */
|
|
|
|
while (lib_isbasedigit(*nptr, base, &value))
|
|
{
|
|
/* Check for overflow */
|
|
|
|
if (accum > limit || (accum == limit && value > last_digit))
|
|
{
|
|
set_errno(ERANGE);
|
|
accum = ULONG_MAX;
|
|
break;
|
|
}
|
|
|
|
accum = accum * base + value;
|
|
nptr++;
|
|
}
|
|
|
|
if (sign == '-')
|
|
{
|
|
accum = (~accum) + 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Return the final pointer to the unused value */
|
|
|
|
if (endptr)
|
|
{
|
|
if (sign)
|
|
{
|
|
if (*(nptr - 1) == sign)
|
|
{
|
|
nptr--;
|
|
}
|
|
}
|
|
|
|
*endptr = (FAR char *)nptr;
|
|
}
|
|
|
|
return accum;
|
|
}
|