FSCTL_SET_SPARSE (Windows CE 5.0)
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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