break;
		case BIO_CTRL_SET_CLOSE:
			dprintf("Got BIO_SET_CLOSE");
			BIO_set_shutdown(bio, num);
			break;
		case BIO_CTRL_EOF:
			dprintf("Got BIO_CTRL_EOF");
			ret = ((chan) ? Tcl_Eof(chan) : 1);
			break;
		case BIO_CTRL_PENDING:
			dprintf("Got BIO_CTRL_PENDING");
			ret = ((chan) ? ((Tcl_InputBuffered(chan) ? 1 : 0)) : 0);
			dprintf("BIO_CTRL_PENDING(%d)", (int) ret);
			break;
		case BIO_CTRL_WPENDING:
			dprintf("Got BIO_CTRL_WPENDING");
			ret = 0;
			break;
		case BIO_CTRL_DUP:
			dprintf("Got BIO_CTRL_DUP");
			break;
		case BIO_CTRL_FLUSH:
			dprintf("Got BIO_CTRL_FLUSH");
			ret = ((chan) && (Tcl_WriteRaw(chan, "", 0) >= 0) ? 1 : -1);
			dprintf("BIO_CTRL_FLUSH returning value %li", ret);
			break;
		default:
			dprintf("Got unknown control command (%i)", cmd);
			ret = -2;
			break;
	}