C / C++ / MFC

kk.tvm wrote:

#define txtmsg(x) write(x)

kk.tvm wrote:

txtmsg("tempvalue = %d", tmpval );

#define txtmsg write

kk.tvm wrote:

I had wrote a code as follows below, is it works fine ?

akashag wrote:

1. Does this type of code may cause some warnings or other issues?

akashag wrote:

2. Is it an optimized approach or do I need to save the value returned by foo()?

#include <Winioctl.h>
VOID LogicalToPhysical(TCHAR *szDrive)
{
	CString szPhysical;
	HANDLE h = CreateFile(szDrive, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE,NULL,OPEN_EXISTING,0,NULL);
	if(INVALID_HANDLE_VALUE != h)
	{
		STORAGE_DEVICE_NUMBER sd;
		DWORD dwRet;
		if(DeviceIoControl(h, IOCTL_STORAGE_GET_DEVICE_NUMBER, NULL, 0, &sd, sizeof(STORAGE_DEVICE_NUMBER), &dwRet, NULL))
		{
			szPhysical.Format(_T("\\\\.\\PhysicalDrive%d"), sd.DeviceNumber);
		}
		CloseHandle(h);
	}
}

//Usage:
LogicalToPhysical(_T("\\\\.\\\\C:"));

Bram van Kampen wrote:

Cannot find the (hex)Value of IOCTL_STORAGE_GET_DEVICE_NUMBER.

#define FILE_ANY_ACCESS                 0
#define FILE_SPECIAL_ACCESS    (FILE_ANY_ACCESS)
#define FILE_READ_ACCESS          ( 0x0001 )    // file & pipe
#define FILE_WRITE_ACCESS         ( 0x0002 )    // file & pipe

#define METHOD_BUFFERED                 0
#define METHOD_IN_DIRECT                1
#define METHOD_OUT_DIRECT               2
#define METHOD_NEITHER                  3

#define FILE_DEVICE_MASS_STORAGE        0x0000002d
#define IOCTL_STORAGE_BASE FILE_DEVICE_MASS_STORAGE

#define CTL_CODE( DeviceType, Function, Method, Access ) (                 \
    ((DeviceType) << 16) | ((Access) << 14) | ((Function) << 2) | (Method) \
)
#define IOCTL_STORAGE_GET_DEVICE_NUMBER       CTL_CODE(IOCTL_STORAGE_BASE, 0x0420, METHOD_BUFFERED, FILE_ANY_ACCESS)

typedef struct _STORAGE_DEVICE_NUMBER {

    //
    // The FILE_DEVICE_XXX type for this device.
    //

    DEVICE_TYPE DeviceType;

    //
    // The number of this device
    //

    DWORD       DeviceNumber;

    //
    // If the device is partitionable, the partition number of the device.
    // Otherwise -1
    //

    DWORD       PartitionNumber;
} STORAGE_DEVICE_NUMBER, *PSTORAGE_DEVICE_NUMBER;