my $key;
while(undef($key)) {
    $key = <STDIN>;
}

##</code><code>##

my $key;
my $term = new POSIX::Termios;
$term->setlflag(~ICANON);  # turn canonical mode off
$term->setcc(VMIN,1);      # read 1 char min
$term->setcc(VTIME,0);     # no timeout
$term->setattr(0,TCSANOW); # apply it to STDIN
while( read(STDIN,$key,1) ) {
    last if(defined($key));
}

##</code><code>##

$term->setlflag(ICANON);   # set back to canonical mode
$term->setattr(0,TCSANOW); # apply it to STDIN
undef($term);  # cleaning up