ieee1284_ref, ieee1284_unref — modify a port's reference count
If you want to free the port list from
ieee1284_find_ports but open one of the
ports later on, you will need to prevent it from being
port has a reference count, and you can use
ieee1284_ref to increment it and
ieee1284_unref to decrement it.
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
ieee1284_unref on it.