write command lines to stdIn

[filmkorn]

Hello,
I was trying to send commandlines to pdPlayer from Pythons subprocess module using stdin.write(). Unfortunately it seems that i'm doing something wront or pdPlayer simply isn't reading stdin.
I was wondering if is was possible to pass Command lines to a pdPlayer instance directly without startin a new instance using --attach. How does the new pdPlayer instance send the command line to the existing instance?

Thanks in advance,

Mitja

[pdimov]

How does the new pdPlayer instance send the command line to the existing instance?

Hi,

Pdplayer uses SendMessage with WM_COPYDATA to pass the (Unicode) command line to the existing window. Here's the relevant section of the code:

static bool try_existing_window( std::wstring const & cmdline )
{
	wchar_t const * class_name = L"__pdplayer_main_class";

	HWND hWnd = FindWindowW( class_name, 0 );

	if( hWnd == 0 )
	{
		return false;
	}
	else
	{
		DWORD dwProcessId = 0;
		GetWindowThreadProcessId( hWnd, &dwProcessId );

		AllowSetForegroundWindow( dwProcessId );

		COPYDATASTRUCT cds = { 0, static_cast< DWORD >( cmdline.size() * 2 ), const_cast< wchar_t * >( cmdline.data() ) };
		SendMessage( hWnd, WM_COPYDATA, 0, (LPARAM)&cds );

		return true;
	}
}

Note that 'cmdline' contains the application name as its first argument, so it would typically be something like "pdplayer64.exe --attach --play_forward". If you just pass "--play_forward", it will be ignored as it will be assumed to be the application name (argv[0]).

[filmkorn]

Thank you Peter,

I got it working!

Cheerz,
Mitja