ieee1284_claim man page
ieee1284_claim — claim access to the port
int ieee1284_claim(struct parport *port);
With the exception of ieee1284_get_deviceid(3), ieee1284_claim must be called on an open port before any other libieee1284 function for accessing a device on it.
Success. Note that, unless the F1284_EXCL flag was specified to start with, the port should be released within a “reasonable” amount of time.
There is not enough memory.
The port parameter is invalid (for instance, it might not have been opened yet).
There was a problem at the operating system level. The global variable errno has been set appropriately.
Tim Waugh <firstname.lastname@example.org>
Copyright © 2001-2003 Tim Waugh
ieee1284_read_data(3), ieee1284_release(3), libieee1284(3).