turn off monitors

turnoffmonitors.cpp

#include <windows.h>

void TurnOffMonitors(BOOL bLock = FALSE)
{
	::PostMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, 2);
	if (bLock) ::LockWorkStation();
}

template <BOOL bLock>
LRESULT CALLBACK HookProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	if (nCode == HC_ACTION)
	{
		KBDLLHOOKSTRUCT *s = (KBDLLHOOKSTRUCT*)lParam;

		switch (s->vkCode)
		{
		case 'L':
			if (wParam == WM_KEYDOWN && GetKeyState(VK_RCONTROL) & 0x8000)
				TurnOffMonitors(bLock);
			break;
		}
	}
	return ::CallNextHookEx(NULL, nCode, wParam, lParam);
}

int CALLBACK WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
	BOOL bDaemon = FALSE;
	BOOL bNoLock = FALSE;

	for (int i = 1; i < __argc; ++i)
	{
		if (strncmp(__argv[i], "-d", 3) == 0)
			bDaemon = TRUE;
		else if (strncmp(__argv[i], "-n", 3) == 0)
			bNoLock = TRUE;
	}

	if (bDaemon)
	{
		if (bNoLock)
			::SetWindowsHookEx(WH_KEYBOARD_LL, HookProc<FALSE>, NULL, 0);
		else
			::SetWindowsHookEx(WH_KEYBOARD_LL, HookProc<TRUE>, NULL, 0);

		MSG msg;
		while (::GetMessage(&msg, NULL, 0, 0))
		{
			::TranslateMessage(&msg);
			::DispatchMessage(&msg);
		}
	}
	else
	{
		TurnOffMonitors(!bNoLock);
	}

	return EXIT_SUCCESS;
}