7.1. What the Spooler Does

LPD controls everything about a host's printers. It's responsible for a number of things:

• It controls access to attached printers and printers attached to other hosts on the network.

• It enables users to submit files to be printed; these submissions are known as jobs.

• It prevents multiple users from accessing a printer at the same time by maintaining a queue for each printer.

• It can print header pages (also known as banner or burst pages) so users can easily find jobs they've printed in a stack of printouts.

• It takes care of communications parameters for printers connected on serial ports.

• It can send jobs over the network to another LPD spooler on another host.

• It can run special filters to format jobs to be printed for various printer languages or printer capabilities.

• It can account for printer usage.

Through a configuration file, and by providing the special filter programs, you can enable the LPD system to do all or some subset of the above for a great variety of printer hardware.