GetLastInputInfoFromWMI.c

#pragma comment (lib, "ole32")
#pragma comment (lib, "oleaut32")
#pragma comment (lib, "wbemuuid")

#include <stdio.h>
#include <windows.h>
#include <wbemidl.h>

void GetLastInputInfoFromWmi()
{
	HRESULT hr = 0;

	IWbemLocator *locator  = NULL;
	IWbemServices *services = NULL;
	IEnumWbemClassObject *results  = NULL;

	BSTR resource = SysAllocString(L"ROOT\\CIMV2");
	BSTR language = SysAllocString(L"WQL");
	BSTR query = SysAllocString(L"SELECT * FROM Win32_process where name=\"csrss.exe\"");

	hr = CoInitializeEx(0, COINIT_MULTITHREADED);
	hr = CoInitializeSecurity(NULL, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL);

	hr = CoCreateInstance(&CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, &IID_IWbemLocator, (LPVOID *) &locator);
	hr = locator->lpVtbl->ConnectServer(locator, resource, NULL, NULL, NULL, 0, NULL, NULL, &services);

	hr = services->lpVtbl->ExecQuery(services, language, query, WBEM_FLAG_BIDIRECTIONAL, NULL, &results);

	if (results != NULL)
	{
		IWbemClassObject *result = NULL;
		ULONG returnedCount = 0;

		while((hr = results->lpVtbl->Next(results, WBEM_INFINITE, 1, &result, &returnedCount)) == S_OK)
		{
			VARIANT roCnt, seId;
			ULONGLONG lCnt = 0;

			hr = result->lpVtbl->Get(result, L"SessionId", 0, &seId, 0, 0);
			printf("Session ID %d\n", seId.uintVal);
			
			hr = result->lpVtbl->Get(result, L"ReadOperationCount", 0, &roCnt, 0, 0);
			VarUI8FromStr(roCnt.bstrVal, GetSystemDefaultLCID(), 0, &lCnt);
			printf("Read Operation Count %llu\n", lCnt);

			result->lpVtbl->Release(result);
		}
	}

	results->lpVtbl->Release(results);
	services->lpVtbl->Release(services);
	locator->lpVtbl->Release(locator);

	CoUninitialize();

	SysFreeString(query);
	SysFreeString(language);
	SysFreeString(resource);

}

void main()
{
	GetLastInputInfoFromWmi();
}