This section provides an overview of the spooler mechanisms used by AIX Version 3.2.5 and AIX Version 4. Because the backend piobe, used to process print jobs on local queues, is the most commonly used and possibly the most complex backend shipped with the AIX operating system, it is used as the primary example in this section. Using piobe in this fashion will allow a better development of AIX spooler concepts. Appropriate notes indicate significant differences between AIX Version 3.2.5 and AIX Version 4.
This section should give the reader a solid impression of the spooler as a real process that has a beginning, discrete points in between (no black boxes), and an ending. If you learn to treat the spooler as a series of components that interact with one another in ways completely dependent upon how a specific queue is configured, three useful events can occur: