use Socket qw(IPPROTO_TCP TCP_NODELAY);

sub nagle(*;$) {
    my $fh = shift;
    if (!@_) {
        return unpack("I", getsockopt($fh, IPPROTO_TCP, TCP_NODELAY) ||
               croak "Could not get Nagle state: $!") ? 0 : 1;
    }
    if (shift) {
        setsockopt($fh, IPPROTO_TCP, TCP_NODELAY, 0) ||
            croak "Couldn't enable Nagle's algorithm: $!";
    } else {
        setsockopt($fh, IPPROTO_TCP, TCP_NODELAY,1) ||
            croak "Couldn't disable Nagle's algorithm: $!";
    }
}