111 lines
5.9 KiB
C
Executable File
111 lines
5.9 KiB
C
Executable File
/**************************************************************************/
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/* */
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/* Copyright (c) Microsoft Corporation. All rights reserved. */
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/* */
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/* This software is licensed under the Microsoft Software License */
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/* Terms for Microsoft Azure RTOS. Full text of the license can be */
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/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
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/* and in the root directory of this software. */
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/* */
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/**************************************************************************/
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/**************************************************************************/
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/**************************************************************************/
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/** */
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/** FileX Component */
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/** */
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/** File */
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/** */
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/**************************************************************************/
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/**************************************************************************/
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#define FX_SOURCE_CODE
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/* Include necessary system files. */
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#include "fx_api.h"
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#include "fx_file.h"
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FX_CALLER_CHECKING_EXTERNS
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/**************************************************************************/
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/* */
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/* FUNCTION RELEASE */
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/* */
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/* _fxe_file_relative_seek PORTABLE C */
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/* 6.1 */
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/* AUTHOR */
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/* */
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/* William E. Lamie, Microsoft Corporation */
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/* */
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/* DESCRIPTION */
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/* */
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/* This function checks for errors in the file relative seek call. */
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/* */
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/* INPUT */
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/* */
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/* file_ptr File control block pointer */
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/* byte_offset Byte offset of the seek */
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/* seek_from Direction for relative seek, */
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/* legal values are: */
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/* */
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/* FX_SEEK_BEGIN */
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/* FX_SEEK_END */
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/* FX_SEEK_FORWARD */
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/* FX_SEEK_BACK */
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/* */
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/* OUTPUT */
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/* */
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/* return status */
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/* */
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/* CALLS */
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/* */
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/* _fx_file_relative_seek Actual relative file seek */
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/* service */
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/* */
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/* CALLED BY */
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/* */
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/* Application Code */
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/* */
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/* RELEASE HISTORY */
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/* */
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/* DATE NAME DESCRIPTION */
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/* */
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/* 05-19-2020 William E. Lamie Initial Version 6.0 */
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/* 09-30-2020 William E. Lamie Modified comment(s), */
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/* resulting in version 6.1 */
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/* */
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/**************************************************************************/
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UINT _fxe_file_relative_seek(FX_FILE *file_ptr, ULONG byte_offset, UINT seek_from)
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{
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UINT status;
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/* Check for a null file pointer. */
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if (file_ptr == FX_NULL)
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{
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return(FX_PTR_ERROR);
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}
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/* Check for valid seek from option. */
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if ((seek_from != FX_SEEK_BEGIN) && (seek_from != FX_SEEK_END) &&
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(seek_from != FX_SEEK_FORWARD) && (seek_from != FX_SEEK_BACK))
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{
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return(FX_INVALID_OPTION);
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}
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/* Check for a valid caller. */
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FX_CALLER_CHECKING_CODE
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/* Call actual file relative seek service. */
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status = _fx_file_relative_seek(file_ptr, byte_offset, seek_from);
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/* Seek is complete, return status. */
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return(status);
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}
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