use Term::ReadKey;
               ReadMode 4; # Turn off controls keys
               while (not defined ($key = ReadKey(-1))) {
                       # No key yet
                       select undef,undef,undef,0.1; # sleep 0.1 second
               }
               print "Get key $key\n";
               ReadMode 0; # Reset tty mode before exiting

##</code><code>##

$ perl test.pl
<press d>
Get key d
$