In order to use printers with FreeBSD, you will need to set them up to work with the
Berkeley line printer spooling system, also known as the LPD
spooling system. It is the standard printer control system in FreeBSD. This chapter
introduces the LPD spooling system, often simply called LPD, and will guide you through its configuration.
If you are already familiar with LPD or another printer
spooling system, you may wish to skip to section Setting up the spooling system.
LPD controls everything about a host's printers. It is
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 have 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 a 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 (/etc/printcap), 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.
If you are the sole user of your system, you may be wondering why you should bother
with the spooler when you do not need access control, header pages, or printer
accounting. While it is possible to enable direct access to a printer, you should use the
spooler anyway since:
-
LPD prints jobs in the background; you do not have to wait
for data to be copied to the printer.
-
LPD can conveniently run a job to be printed through
filters to add date/time headers or convert a special file format (such as a TeX DVI
file) into a format the printer will understand. You will not have to do these steps
manually.
-
Many free and commercial programs that provide a print feature usually expect to talk
to the spooler on your system. By setting up the spooling system, you will more easily
support other software you may later add or already have.
