Low-Level Keyboard Input Detection

[Don Guy]

Hey there, I am writing an software that should be able to detect all keyboard inputs by the user. i.e., both hardware and software/on-screen keyboard. This software is going to be written in a platform independent way and supposed to run on Windows, Linux, Android & iOS. The idea is to capture the keyboard inputs from a low level, there by making sure that it doesn't miss any inputs even if it's a on-screen keyboard like in a mobile device. I am looking at possible open source libraries that can be used. Anyone got any good ideas on what to use? Thanks in advance!

[Lost User]

Given that those platforms have very different operating systems and hardware it is unlikely that you will find a library that can handle each type, especially at the hardware level. If you want open source code then Google should be your search tool.

[Rage]

A cross-plattform key-logger :~ ? This sounds like the ultimate trojan, so finding resources will not be easy...

~RaGE();

I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Entropy isn't what it used to.

[Software_Developer]

For Windows, here is a global key hook example, prints pressed keycodes to the console. It even works when it's in the background. And this is a Windows discussion board, also ask in Linux, Android and IOS sections for answers..

#include
#include

HHOOK hKeyboardHook;

__declspec(dllexport) LRESULT CALLBACK KeyboardEvent (int nCode, WPARAM wParam, LPARAM lParam)
{
DWORD SHIFT_key=0;
DWORD CTRL_key=0;
DWORD ALT_key=0;

if  ((nCode == HC\_ACTION) &&   ((wParam == WM\_SYSKEYDOWN) ||  (wParam == WM\_KEYDOWN)))      
{
	KBDLLHOOKSTRUCT hooked\_key = 	\*((KBDLLHOOKSTRUCT\*)lParam);
	DWORD dwMsg = 1;
	dwMsg += hooked\_key.scanCode << 16;
	dwMsg += hooked\_key.flags << 24;
	char lpszKeyName\[1024\] = {0};
	lpszKeyName\[0\] = '\[';

	int i = GetKeyNameText(dwMsg,	(lpszKeyName+1),0xFF) + 1;
	lpszKeyName\[i\] = '\]';

	int key = hooked\_key.vkCode;

	SHIFT\_key = GetAsyncKeyState(VK\_SHIFT);
	CTRL\_key = GetAsyncKeyState(VK\_CONTROL);
    ALT\_key = GetAsyncKeyState(VK\_MENU);

	if (key >= 'A' && key <= 'Z')   mmmmmmcjmcfkgkgcgkj.j.g     
	{
		 
		if  (GetAsyncKeyState(VK\_SHIFT)>= 0) key +=32;

		if (CTRL\_key !=0 && key == 'y' )
		{
           MessageBox(NULL, "CTRL-y was pressed\\nLaunch your app here", "H O T K E Y", MB\_OK); 
           CTRL\_key=0;
		}

		if (CTRL\_key !=0 && key == 'q' )
		{
			MessageBox(NULL, "Shutting down", "H O T K E Y", MB\_OK); 
           PostQuitMessage(0);
		}




		printf("key = %c\\n", key);

		SHIFT\_key = 0;
		CTRL\_key = 0;
		ALT\_key = 0;

	}

	printf("lpszKeyName = %s\\n",  lpszKeyName );
}
return CallNextHookEx(hKeyboardHook,	nCode,wParam,lParam);

}

void MessageLoop()
{
MSG message;
while (GetMessage(&message,NULL,0,0))
{
TranslateMessage( &message );
DispatchMessage( &message );
}
}

DWORD WINAPI my_HotKey(LPVOID lpParm)
{
HINSTANCE hInstance = GetModuleHandle(NULL);
if (!hInstance) hInstance = LoadLibrary((LPCSTR) lpParm);
if (!hInstance) return 1;

hKeyboardHook = SetWindowsHookEx ( 	WH\_KEYBOARD\_LL, (HOOKPROC) KeyboardEvent,  	hInstance,  NULL    );
MessageLoop();
UnhookWindowsHookEx(hKeyboardHook);
return 0;

}

int main(int argc, char** argv)
{
HANDLE hThread;
DWORD dwThread;

hThread = CreateThread(NULL,NULL,(LPTHREAD\_START\_ROUTINE) 	my\_HotKey, (LPVOID) argv\[0\], NULL, &dwThread);

//ShowWindow(FindWindowA("ConsoleWindowClass", NULL), false);

if (hThread) return WaitForSingleObject(hThread,INFINI

[Don Guy]

Thanks for the code! Does this work if it's a on-screen/software key board?