#include <ieee1284.h>
If you use ieee1284_ref at any stage, you must later call ieee1284_unref to relinquish the extra reference. If you do not do this, the resources associated with the port will not be cleaned up.
If you have not previously used ieee1284_ref on a port, you must not use ieee1284_unref on it.
These functions return the number of references held after the increment or decrement.
Tim Waugh <twaugh@redhat.com>