sendKey.cpp

#include <iostream>
#include <windows.h>
#pragma comment (lib, "user32")
bool keyPressed(char key)
{
    return GetAsyncKeyState(key) == -32767;
}
void sendKey(char key)
{
    INPUT ip;
    ip.type = INPUT_KEYBOARD;
    ip.ki.wScan =  0;
    ip.ki.time = 0;
    ip.ki.dwExtraInfo = 0;

    ip.ki.dwFlags = 0;
    ip.ki.wVk = key;
    SendInput(1, &ip, sizeof(INPUT));
    ip.ki.dwFlags = KEYEVENTF_KEYUP;
    SendInput(1, &ip, sizeof(INPUT));
}
int main()
{
    std::cout << "Running...\n";
    int delay = 16;
    char originalKey = VK_SPACE;
    char keyToSend = VK_LWIN;
    while(true)
    {
        if(keyPressed(originalKey))
        {
            sendKey(keyToSend);
            std::cout << "PRESSED\n";
        }
        Sleep(delay);
    }
}