FSCTL_SET_SPARSE (Windows CE 5.0)

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This IOCTL marks an indicated file as sparse. In a sparse file, large ranges of zeros may not require disk allocation. Space for nonzero data will be allocated as needed as the file is written.

Parameters

  • hDevice
    [in] Handle to the file or alternate stream to be made sparse. To retrieve a handle, call the CreateFile function.
  • dwIoControlCode
    [in] Set to FSCTL_SET_SPARSE.
  • lpInBuf
    Not used. Set to NULL.
  • nInBufSize
    Not used. Set to zero.
  • lpOutBuf
    Not used. Set to NULL.
  • nOutBufSize
    Not used. Set to NULL.
  • lpBytesReturned
    [out] Pointer to a variable that receives the size of the data stored in the output buffer, in bytes.
  • lpOverlapped
    Not used.

Return Values

If the operation succeeds, DeviceIoControl returns a nonzero value.

If the operation fails, DeviceIoControl returns zero. For extended error information, call GetLastError.

Remarks

This IOCTL sets the FILE_ATTRIBUTE_SPARSE_FILE attribute of the specified file. The only way to clear this attribute is to overwrite the file, for example, by calling the CreateFile function with the CREATE_ALWAYS flag.

Requirements

OS Versions: Windows CE 5.0 and later.
Header: Fsioctl.h

See Also

FSD IOCTLs | CreateFile | DeviceIoControl | GetLastError

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