incubator-nuttx/libs/libc/string/lib_isbasedigit.c

92 lines
2.7 KiB
C

/****************************************************************************
* libs/libc/string/lib_isbasedigit.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 <stdbool.h>
#include <string.h>
#include <ctype.h>
#include "libc.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_isbasedigit
*
* Description:
* Given an ASCII character, ch, and a base (1-36) do two
* things: 1) Determine if ch is a valid character, and 2)
* convert ch to its binary value.
*
****************************************************************************/
bool lib_isbasedigit(int ch, int base, int *value)
{
bool ret = false;
int tmp = 0;
if (base <= 10)
{
if (ch >= '0' && ch <= base + '0' - 1)
{
tmp = ch - '0';
ret = true;
}
}
else if (base <= 36)
{
if (ch >= '0' && ch <= '9')
{
tmp = ch - '0';
ret = true;
}
else if (ch >= 'a' && ch <= 'a' + base - 11)
{
tmp = ch - 'a' + 10;
ret = true;
}
else if (ch >= 'A' && ch <= 'A' + base - 11)
{
tmp = ch - 'A' + 10;
ret = true;
}
}
if (ret && value)
{
*value = tmp;
}
return ret;
}