See Also
 Important: |
|---|
| This is retired content. This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist. |
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 CreateFilefunction.
- 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 DeviceIoControlfunction returns a nonzero value. If the operation fails, DeviceIoControlreturns 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 CreateFilefunction with the CREATE_ALWAYS flag.
Requirements
| Header | fsioctl.h |
| Windows Embedded CE | Windows CE 5.0 and later |
| Windows Mobile | Windows Mobile Version 5.0 and later |