116 lines
3.7 KiB
C
116 lines
3.7 KiB
C
/****************************************************************************
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* libc/stdlib/lib_checkbase.c
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*
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* Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <string.h>
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#include <ctype.h>
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#include "lib_internal.h"
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: lib_checkbase
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*
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* Description:
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* This is part of the strol() family implementation. This function checks
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* the initial part of a string to see if it can determine the numeric
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* base that is represented.
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*
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* Assumptions:
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* *ptr points to the first, non-whitespace character in the string.
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*
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****************************************************************************/
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int lib_checkbase(int base, FAR const char **pptr)
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{
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const char *ptr = *pptr;
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/* Check for unspecified base */
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if (!base)
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{
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/* Assume base 10 */
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base = 10;
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/* Check for leading '0' - that would signify octal or hex (or binary) */
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if (*ptr == '0')
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{
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/* Assume octal */
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base = 8;
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ptr++;
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/* Check for hexadecimal */
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if ((*ptr == 'X' || *ptr == 'x') &&
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lib_isbasedigit(ptr[1], 16, NULL))
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{
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base = 16;
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ptr++;
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}
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}
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}
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/* If it a hexadecimal representation, than discard any leading "0X" or "0x" */
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else if (base == 16)
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{
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if (ptr[0] == '0' && (ptr[1] == 'X' || ptr[1] == 'x'))
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{
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ptr += 2;
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}
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}
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/* Return the updated pointer and base */
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*pptr = ptr;
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return base;
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}
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