FSCTL_SET_SPARSE
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4/8/2010
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 |
| Windows Mobile | Windows Mobile Version 5.0 and later |