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MyFSD_SetEndOfFile (Compact 2013)

  • Artigo

3/26/2014

This function moves the end-of-file position for the specified file in an installable file system to the current position of the file pointer. The application does not call this function directly. Instead, it uses the corresponding standard Win32 function SetEndOfFile. The File System Disk Manager (FSDMGR) determines the file system type and calls the MyFSD_SetEndOfFile implementation of the function.

Syntax

BOOL MyFSD_SetEndOfFile( 
  PFILE pFile
);

Parameters

  • pFile
    [in] Pointer to the value that an FSD passes to the FSDMGR_CreateFileHandle function when creating the file handle.

Return Value

Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError.

Remarks

An FSD exports this function if it supports the SetEndOfFile function. All FSD functions can be called on re-entry. Therefore, take this into account when developing an FSD.

FSDMGR is a DLL that manages all OS interaction with installable files systems. Each installable file system requires an FSD, which is a DLL that supports an installable file system. The name of the DLL and the names of the functions it exports start with the name of the associated installable file system. For example, if the name of file system is MyFSD, its DLL is MyFSD.dll, and its exported functions are prefaced with MyFSD_*.

FSDMGR provides services to FSDs. The FSDMGR_RegisterVolume, the FSDMGR_CreateFileHandle, and the FSDMGR_CreateSearchHandle functions record a DWORD of volume-specific data that an FSD associates with a volume. This volume-specific data is passed as the first parameter of these three functions.

Applications that access an installable file system use standard Win32 functions. For example, when an application creates a folder on a device that contains an installable file system, it calls the CreateDirectory function. FSDMGR recognizes that the path is to a device containing an installable file system and calls the appropriate function, which in the case of the FAT file system is FATFSD_CreateDirectoryW.That is, the application calls CreateDirectory, causing FSDMGR to call FATFSD_CreateDirectoryW.

This function can be used to truncate or extend a file. If the file is extended, the contents of the file between the old end-of-file position and the new position are not defined.

Requirements

Header

fsdmgr.h

Library

Fsdmgr.lib

See Also

Reference

MyFSD Functions
CreateDirectory
CreateFile
FSDMGR_CreateFileHandle
FSDMGR_CreateSearchHandle
FSDMGR_RegisterVolume
SetEndOfFile