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FSCTL_SET_SPARSE (Windows Embedded CE 6.0)

1/6/2010

This I/O control marks the specified file as sparse. In a sparse file, large ranges of zeros may not require disk allocation. Space for nonzero data is allocated as needed as the file is written.

Parameters

  • hDevice
    [in] Handle to the file or alternate stream to be made sparse. To obtain 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, the DeviceIoControl function returns a nonzero value. If the operation fails, DeviceIoControl returns zero. For extended error information, call GetLastError.

Remarks

This I/O control 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

Header fsioctl.h
Windows Embedded CE Windows CE 5.0 and later

See Also

Reference

FS I/O Controls
CreateFile

Other Resources

DeviceIoControl