1130b656e5
This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
3877 lines
142 KiB
Plaintext
3877 lines
142 KiB
Plaintext
<!-- This is an SGML document in the linuxdoc DTD describing
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Printing with FreeBSD. By Sean Kelly, 1995.
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$FreeBSD$
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The FreeBSD Documentation Project
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<!DOCTYPE linuxdoc PUBLIC "-//FreeBSD//DTD linuxdoc//EN">
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<article>
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<title> Printing with FreeBSD
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<author> Sean Kelly <tt/kelly@fsl.noaa.gov/
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<date> 30 September 1995, (c) 1995
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<abstract> This document describes printing with FreeBSD. It
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tells how to set up printer hardware, how to configure FreeBSD
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to use printers, and how to control the print queue and print
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a variety of file formats. </abstract>
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<toc>
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-->
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<chapt><heading>Printing<label id="printing"></heading>
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<p><em>Contributed by &a.kelly;<newline>30 September 1995</em>
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In order to use printers with FreeBSD, you will need to set
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them up to work with the Berkeley line printer spooling
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system, also known as the LPD spooling system. It is the
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standard printer control system in FreeBSD. This section
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introduces the LPD spooling system, often simply called LPD.
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If you are already familiar with LPD or another printer
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spooling system, you may wish to skip to section <ref
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id="printing:intro:setup" name="Setting up the spooling
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system">.
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<sect><heading>What the Spooler Does<label
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id="printing:intro:spooler"></heading>
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<p> LPD controls everything about a host's printers. It is
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responsible for a number of things:
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<itemize>
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<item>It controls access to attached printers and
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printers attached to other hosts on the network.
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<item>It enables users to submit files to be printed;
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these submissions are known as <em/jobs/.
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<item>It prevents multiple users from accessing a printer
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at the same time by maintaining a <em/queue/ for each
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printer.
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<item>It can print <em/header pages/ (also known as
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<em/banner/ or <em/burst/ pages) so users can easily
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find jobs they have printed in a stack of printouts.
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<item>It takes care of communications parameters for
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printers connected on serial ports.
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<item>It can send jobs over the network to another LPD
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spooler on another host.
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<item>It can run special filters to format jobs to be
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printed for various printer languages or printer
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capabilities.
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<item>It can account for printer usage.
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</itemize>
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Through a configuration file, and by providing the special
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filter programs, you can enable the LPD system to do all or
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some subset of the above for a great variety of printer
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hardware.
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<sect><heading>Why You Should Use the Spooler<label
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id="printing:intro:why"></heading>
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<p> If you are the sole user of your system, you may be
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wondering why you should bother with the spooler when you
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do not need access control, header pages, or printer
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accounting. While it is possible to enable direct access to
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a printer, you should use the spooler anyway since
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<itemize>
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<item>LPD prints jobs in the background; you do not have
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to wait for data to be copied to the printer.
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<item>LPD can conveniently run a job to be printed
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through filters to add date/time headers or convert a
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special file format (such as a TeX DVI file) into a
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format the printer will understand. You will not have to do
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these steps manually.
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<item>Many free and commercial programs that provide a
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print feature usually expect to talk to the spooler on
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your system. By setting up the spooling system, you will
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more easily support other software you may later add or
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already have.
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</itemize>
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<sect><heading>Setting Up the Spooling System<label
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id="printing:intro:setup"></heading>
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<p> To use printers with the LPD spooling system, you will need
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to set up both your printer hardware and the LPD software.
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This document describes two levels of setup:
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<itemize>
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<item>See section <ref name="Simple Printer Setup"
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id="printing:simple"> to learn how to connect a
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printer, tell LPD how to communicate with it, and
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print plain text files to the printer.
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<item>See section <ref name="Advanced Printer Setup"
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id="printing:advanced"> to find out how to print a
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variety of special file formats, to print header
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pages, to print across a network, to control access to
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printers, and to do printer accounting.
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</itemize>
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<sect><heading>Simple Printer Setup<label
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id="printing:simple"></heading>
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<p> This section tells how to configure printer hardware and the
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LPD software to use the printer. It teaches the basics:
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<itemize>
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<item>Section <ref id="printing:hardware" name="Hardware
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Setup"> gives some hints on connecting the printer to a
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port on your computer.
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<item>Section <ref id="printing:software" name="Software
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Setup"> shows how to setup the LPD spooler configuration
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file <tt>/etc/printcap</tt>.
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</itemize>
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If you are setting up a printer that uses a network protocol
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to accept data to print instead of a serial or parallel interface,
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see <ref id="printing:advanced:network:net-if" name="Printers
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With Networked Data Stream Interaces">.
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Although this section is called ``Simple Printer Setup,'' it is
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actually fairly complex. Getting the printer to work with
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your computer and the LPD spooler is the hardest part. The
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advanced options like header pages and accounting are fairly
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easy once you get the printer working.
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<sect1><heading>Hardware Setup<label id="printing:hardware"></heading>
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<p> This section tells about the various ways you can connect a
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printer to your PC. It talks about the kinds of ports and
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cables, and also the kernel configuration you may need to
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enable FreeBSD to speak to the printer.
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If you have already connected your printer and have
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successfully printed with it under another operating system,
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you can probably skip to section <ref id="printing:software"
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name="Software Setup">.
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<sect2><heading>Ports and Cables<label
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id="printing:ports"></heading>
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<p> Nearly all printers you can get for a PC today support
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one or both of the following interfaces:
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<itemize>
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<item><em/Serial/ interfaces use a serial port on your
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computer to send data to the printer. Serial
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interfaces are common in the computer industry and
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cables are readily available and also easy to
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construct. Serial interfaces sometimes need special
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cables and might require you to configure somewhat
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complex communications options.
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<item><em/Parallel/ interfaces use a parallel port on
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your computer to send data to the printer. Parallel
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interfaces are common in the PC market. Cables are
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readily available but more difficult to construct by
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hand. There are usually no communications options
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with parallel interfaces, making their configuration
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exceedingly simple.
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<p> Parallel interfaces are sometimes known as
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``Centronics'' interfaces, named after the connector
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type on the printer.
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</itemize>
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In general, serial interfaces are slower than parallel
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interfaces. Parallel interfaces usually offer just
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one-way communication (computer to printer) while serial
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gives you two-way. Many newer parallel ports can also
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receive data from the printer, but only few printers need
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to send data back to the computer. And FreeBSD does not
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support two-way parallel communication yet.
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Usually, the only time you need two-way communication with
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the printer is if the printer speaks PostScript.
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PostScript printers can be very verbose. In fact,
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PostScript jobs are actually programs sent to the printer;
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they need not produce paper at all and may return results
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directly to the computer. PostScript also uses
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two-way communication to tell the computer about problems,
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such as errors in the PostScript program or paper jams.
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Your users may be appreciative of such information.
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Furthermore, the best way to do effective accounting with
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a PostScript printer requires two-way communication: you
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ask the printer for its page count (how many pages it has
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printed in its lifetime), then send the user's job, then
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ask again for its page count. Subtract the two values and
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you know how much paper to charge the user.
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So, which interface should you use?
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<itemize>
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<item>If you need two-way communication, use a serial
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port. FreeBSD does not yet support two-way
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communication over a parallel port.
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<item>If you do not need two-way communication and can
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pick parallel or serial, prefer the parallel
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interface. It keeps a serial port free for other
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peripherals---such as a terminal or a modem---and is
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faster most of the time. It is also easier to
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configure.
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<item>Finally, use whatever works.
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</itemize>
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<sect2><heading>Parallel Ports<label id="printing:parallel"></heading>
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<p> To hook up a printer using a parallel interface, connect
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the Centronics cable between the printer and the
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computer. The instructions that came with the printer, the
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computer, or both should give you complete guidance.
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Remember which parallel port you used on the computer. The
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first parallel port is /dev/lpt0 to FreeBSD; the second is
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/dev/lpt1, and so on.
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<sect2><heading>Serial Ports<label id="printing:serial"></heading>
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<p> To hook up a printer using a serial interface, connect
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the proper serial cable between the printer and the
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computer. The instructions that came with the printer,
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the computer, or both should give you complete guidance.
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If you are unsure what the ``proper serial cable'' is, you
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may wish to try one of the following alternatives:
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<itemize>
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<item>A <em/modem/ cable connects each pin of the
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connector on one end of the cable straight through to
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its corresponding pin of the connector on the other
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end. This type of cable is also known as a DTE-to-DCE
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cable.
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<item>A <em/null-modem/ cable connects some pins
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straight through, swaps others (send data to receive
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data, for example), and shorts some internally in each
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connector hood. This type of cable is also known as a
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DTE-to-DTE cable.
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<item>A <em/serial printer/ cable, required for some
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unusual printers, is like the null modem cable, but
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sends some signals to their counterparts instead of
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being internally shorted.
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</itemize>
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You should also set up the communications parameters for
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the printer, usually through front-panel controls or DIP
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switches on the printer. Choose the highest bps (bits per
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second, sometimes <em/baud rate/) rate that both your
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computer and the printer can support. Choose 7 or 8 data
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bits; none, even, or odd parity; and 1 or 2 stop bits.
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Also choose a flow control protocol: either none, or
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XON/XOFF (also known as <em/in-band/ or <em/software/)
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flow control. Remember these settings for the software
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configuration that follows.
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<sect1><heading>Software Setup<label id="printing:software"></heading>
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<p> This section describes the software setup necessary to
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print with the LPD spooling system in FreeBSD.
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Here is an outline of the steps involved:
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<enum>
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<item>Configure your kernel, if necessary, for the port
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you are using for the printer; section <ref
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id="printing:kernel" name="Kernel Configuration"> tells
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you what you need to do.
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<item>Set the communications mode for the parallel port,
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if you are using a parallel port; section <ref
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id="printing:parallel-port-mode" name = "Setting the
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Communication Mode for the Parallel Port"> gives
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details.
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<item>Test if the operating system can send data to the
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printer. Section <ref id="printing:testing"
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name="Checking Printer Communications"> gives some
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suggestions on how to do this.
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<item>Set up LPD for the printer by modifying the file
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<tt>/etc/printcap</tt>. Section <ref
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id="printing:printcap" name="The /etc/printcap File">
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shows you how.
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</enum>
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<sect2><heading>Kernel Configuration<label
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id="printing:kernel"></heading>
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<p> The operating system kernel is compiled to work with a
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specific set of devices. The serial or parallel interface
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for your printer is a part of that set. Therefore, it
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might be necessary to add support for an additional serial
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or parallel port if your kernel is not already configured
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for one.
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To find out if the kernel you are currently using supports a serial
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interface, type
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<tscreen>
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<tt>dmesg | grep sio</tt><it/N/
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</tscreen>
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where <it/N/ is the number of the serial port, starting
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from zero. If you see output similar to the following
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<tscreen><verb>
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sio2 at 0x3e8-0x3ef irq 5 on isa
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sio2: type 16550A
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</verb></tscreen>
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then the kernel supports the port.
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To find out if the kernel supports a parallel interface,
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type
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<tscreen>
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<tt>dmesg | grep lpt</tt><it/N/
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</tscreen>
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where <it/N/ is the number of the parallel port, starting
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from zero. If you see output similar to the following
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<tscreen><verb>
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lpt0 at 0x378-0x37f on isa
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</verb></tscreen>
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then the kernel supports the port.
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You might have to reconfigure your kernel in order for the
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operating system to recognize and use the parallel or
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serial port you are using for the printer.
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To add support for a serial port, see the section on
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kernel configuration. To add support for a parallel port,
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see that section <em/and/ the section that follows.
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<sect3><heading>Adding <tt>/dev</tt> Entries for the Ports
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<label id="printing:dev-ports"></heading>
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<p> Even though the kernel may support communication along
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a serial or parallel port, you will still need a software
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interface through which programs running on the system
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can send and receive data. That is what entries in the
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<tt>/dev</tt> directory are for.
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<bf>To add a <tt>/dev</tt> entry for a port:</bf>
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<enum>
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<item>Become root with the <tt/su/ command. Enter
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the root password when prompted.
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<item>Change to the <tt>/dev</tt> directory:
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<tscreen><verb>
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cd /dev
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</verb></tscreen>
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<item>Type
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<tscreen>
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<tt> ./MAKEDEV</tt> <it/port/
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</tscreen>
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where <it/port/ is the device entry for the port you
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want to make. Use <tt/lpt0/ for the first parallel
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port, <tt/lpt1/ for the second, and so on; use
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<tt/ttyd0/ for the first serial port, <tt/ttyd1/ for
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the second, and so on.
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<item>Type
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<tscreen>
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<tt>ls -l</tt> <it/port/
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</tscreen>
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to make sure the device entry got created.
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</enum>
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<sect3><heading>Setting the Communication Mode for the Parallel Port
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<label id="printing:parallel-port-mode"></heading>
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<p> When you are using the parallel interface, you can
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choose whether FreeBSD should use interrupt-driven or
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polled communication with the printer.
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<itemize>
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<item>The <em/interrupt-driven/ method is the default
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with the GENERIC kernel. With this method, the
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operating system uses an IRQ line to determine when
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the printer is ready for data.
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<item>The <em/polled/ method directs the operating
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system to repeatedly ask the printer if it is ready
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for more data. When it responds ready, the kernel
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sends more data.
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</itemize>
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The interrupt-driven method is somewhat faster but uses
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up a precious IRQ line. You should use whichever one
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works.
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You can set the communications mode in two ways: by
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configuring the kernel or by using the <tt/lptcontrol/
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program.
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<bf>To set the communications mode by configuring the
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kernel:</bf>
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<enum>
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<item>Edit your kernel configuration file. Look for
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or add an <tt/lpt0/ entry. If you are setting up the
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second parallel port, use <tt/lpt1/ instead. Use
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<tt/lpt2/ for the third port, and so on.
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<itemize>
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<item>If you want interrupt-driven mode, add the <tt/irq/
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specifier:
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<tscreen>
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<tt>device lpt0 at isa? port? tty irq <it/N/ vector lptintr</tt>
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</tscreen>
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where <it/N/ is the IRQ number for your
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computer's parallel port.
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<item>If you want polled mode, do not add the
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<tt/irq/ specifier:
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<tscreen>
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<tt>device lpt0 at isa? port? tty vector lptintr</tt>
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</tscreen>
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</itemize>
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<item>Save the file. Then configure, build, and
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install the kernel, then reboot. See <ref id="kernelconfig"
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name="kernel configuration"> for more details.
|
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</enum>
|
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<bf>To set the communications mode with
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<tt/lptcontrol/:</bf>
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<itemize>
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<item>
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Type
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<tscreen>
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<tt>lptcontrol -i -u <it/N/</tt>
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</tscreen>
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to set interrupt-driven mode for <tt/lpt<it/N//.
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<item>
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Type
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<tscreen>
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<tt>lptcontrol -p -u <it/N/</tt>
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</tscreen>
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to set polled-mode for <tt/lpt<it/N//.
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</itemize>
|
|
You could put these commands in your
|
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<tt>/etc/rc.local</tt> file to set the mode each time
|
|
your system boots. See lptcontrol(8) for more
|
|
information.
|
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|
|
<sect3><heading>Checking Printer Communications<label
|
|
id="printing:testing"></heading>
|
|
|
|
<p> Before proceeding to configure the spooling system,
|
|
you should make sure the operating system can
|
|
successfully send data to your printer. It is a lot
|
|
easier to debug printer communication and the spooling
|
|
system separately.
|
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|
|
To test the printer, we will send some text to it. For
|
|
printers that can immediately print characters sent to
|
|
them, the program <tt/lptest/ is perfect: it generates
|
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all 96 printable ASCII characters in 96 lines.
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|
|
For a PostScript (or other language-based) printer,
|
|
we will need a more sophisticated test. A small
|
|
PostScript program, such as the following, will suffice:
|
|
<code>
|
|
%!PS
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100 100 moveto 300 300 lineto stroke
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310 310 moveto
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/Helvetica findfont 12 scalefont setfont
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(Is this thing working?) show
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showpage
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</code>
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<em/Note:/ When this document refers to a printer
|
|
language, I am assuming a language like PostScript, and
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not Hewlett Packard's PCL. Although PCL has great
|
|
functionality, you can intermingle plain text with its
|
|
escape sequences. PostScript cannot directly print
|
|
plain text, and that is the kind of printer language for
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|
which we must make special accommodations.
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|
|
<sect4><heading>Checking a Parallel Printer<label
|
|
id="printing:checking:parallel"></heading>
|
|
|
|
<p> This section tells you how to check if FreeBSD can
|
|
communicate with a printer connected to a parallel port.
|
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|
|
<bf>To test a printer on a parallel port:</bf>
|
|
<enum>
|
|
<item>Become root with <tt/su/.
|
|
<item>Send data to the printer.
|
|
<itemize>
|
|
<item>If the printer can print plain text, then
|
|
use <tt/lptest/. Type:
|
|
<tscreen>
|
|
<tt>lptest > /dev/lpt<it/N/</tt>
|
|
</tscreen>
|
|
where <it/N/ is the number of the parallel
|
|
port, starting from zero.
|
|
|
|
<item>If the printer understands PostScript or
|
|
other printer language, then send a small
|
|
program to the printer. Type
|
|
<tscreen>
|
|
<tt>cat > /dev/lpt<it/N/</tt>
|
|
</tscreen>
|
|
Then, line by line, type the program
|
|
<em/carefully/ as you cannot edit a line once
|
|
you have pressed RETURN or ENTER. When you have
|
|
finished entering the program, press
|
|
CONTROL+D, or whatever your end of file key
|
|
is.
|
|
|
|
<p> Alternatively, you can put the program in
|
|
a file and type
|
|
<tscreen>
|
|
<tt>cat <it/file/ > /dev/lpt<it/N/</tt>
|
|
</tscreen>
|
|
where <it/file/ is the name of the file
|
|
containing the program you want to send to
|
|
the printer.
|
|
</itemize>
|
|
</enum>
|
|
|
|
You should see something print. Do not worry if the
|
|
text does not look right; we will fix such things later.
|
|
|
|
<sect4><heading>Checking a Serial Printer<label
|
|
id="printing:checking:serial"></heading>
|
|
|
|
<p> This section tells you how to check if FreeBSD can
|
|
communicate with a printer on a serial port.
|
|
|
|
<bf>To test a printer on a serial port:</bf>
|
|
<enum>
|
|
<item>Become root with <tt/su/.
|
|
|
|
<item>Edit the file <tt>/etc/remote</tt>. Add the
|
|
following entry:
|
|
<tscreen>
|
|
<tt>printer:dv=/dev/<it/port/:br#<it/bps-rate/:pa=<it/parity/</tt>
|
|
</tscreen>
|
|
where <it/port/ is the device entry for the serial
|
|
port (<tt/ttyd0/, <tt/ttyd1/, etc.), <it/bps-rate/
|
|
is the bits-per-second rate at which the printer
|
|
communicates, and <it/parity/ is the parity
|
|
required by the printer (either <tt/even/,
|
|
<tt/odd/, <tt/none/, or <tt/zero/).
|
|
<p>
|
|
Here is a sample entry for a printer connected
|
|
via a serial line to the third serial port at
|
|
19200 bps with no parity:
|
|
<code>
|
|
printer:dv=/dev/ttyd2:br#19200:pa=none
|
|
</code>
|
|
|
|
<item>Connect to the printer with <tt/tip/. Type:
|
|
<tscreen><verb>
|
|
tip printer
|
|
</verb></tscreen>
|
|
If this step does not work, edit the file
|
|
<tt>/etc/remote</tt> again and try using
|
|
<tt>/dev/cuaa<it/N/</tt> instead of
|
|
<tt>/dev/ttyd<it/N/</tt>.
|
|
|
|
<item>Send data to the printer.
|
|
<itemize>
|
|
<item>If the printer can print plain text, then
|
|
use <tt/lptest/. Type:
|
|
<tscreen><verb>
|
|
~$lptest
|
|
</verb></tscreen>
|
|
|
|
<item>If the printer understands PostScript or
|
|
other printer language, then send a small
|
|
program to the printer. Type the program,
|
|
line by line, <em/very carefully/ as
|
|
backspacing or other editing keys may be
|
|
significant to the printer. You may also need
|
|
to type a special end-of-file key for the
|
|
printer so it knows it received the whole
|
|
program. For PostScript printers, press
|
|
CONTROL+D.
|
|
|
|
<p> Alternatively, you can put the program in
|
|
a file and type
|
|
<tscreen>
|
|
<tt>˜><it/file/</tt>
|
|
</tscreen>
|
|
where <it/file/ is the name of the file
|
|
containing the program. After <tt/tip/
|
|
sends the file, press any required
|
|
end-of-file key.
|
|
</itemize>
|
|
</enum>
|
|
|
|
You should see something print. Do not worry if the
|
|
text does not look right; we will fix that later.
|
|
|
|
<sect2><heading>Enabling the Spooler: The <tt>/etc/printcap</tt> File
|
|
<label id="printing:printcap"></heading>
|
|
|
|
<p> At this point, your printer should be hooked up, your
|
|
kernel configured to communicate with it (if necessary),
|
|
and you have been able to send some simple data to the
|
|
printer. Now, we are ready to configure LPD to control
|
|
access to your printer.
|
|
|
|
You configure LPD by editing the file
|
|
<tt>/etc/printcap</tt>. The LPD spooling system reads
|
|
this file each time the spooler is used, so updates to the
|
|
file take immediate effect.
|
|
|
|
The format of the <tt/printcap/ file is straightforward.
|
|
Use your favorite text editor to make changes to
|
|
<tt>/etc/printcap</tt>. The format is identical to other
|
|
capability files like <tt>/usr/share/misc/termcap</tt> and
|
|
<tt>/etc/remote</tt>. For complete information about the
|
|
format, see the cgetent(3).
|
|
|
|
The simple spooler configuration consists of the following steps:
|
|
<enum>
|
|
<item>Pick a name (and a few convenient aliases) for
|
|
the printer, and put them in the
|
|
<tt>/etc/printcap</tt> file; see <ref
|
|
id="printing:naming" name="Naming the Printer">.
|
|
|
|
<item>Turn off header pages (which are on by default)
|
|
by inserting the <tt/sh/ capability; see <ref
|
|
id="printing:no-header-pages" name="Suppressing Header
|
|
Pages">.
|
|
|
|
<item>Make a spooling directory, and specify its
|
|
location with the <tt/sd/ capability; see <ref
|
|
id="printing:spooldir" name="Making the Spooling
|
|
Directory">.
|
|
|
|
<item>Set the <tt>/dev</tt> entry to use for the
|
|
printer, and note it in <tt>/etc/printcap</tt> with
|
|
the <tt/lp/ capability; see <ref id="printing:device"
|
|
name="Identifying the Printer Device">. Also, if the
|
|
printer is on a serial port, set up the communication
|
|
parameters with the <tt/fs/, <tt/fc/, <tt/xs/, and
|
|
<tt/xc/ capabilities; see <ref id="printing:commparam"
|
|
name="Configuring Spooler Communications Parameters">.
|
|
|
|
<item>Install a plain text input filter; see <ref
|
|
id="printing:textfilter" name="Installing the Text
|
|
Filter">
|
|
|
|
<item>Test the setup by printing something with the
|
|
<tt/lpr/ command; see <ref id="printing:trying"
|
|
name="Trying It Out"> and <ref
|
|
id="printing:troubleshooting" name="Troubleshooting">.
|
|
</enum>
|
|
|
|
<em/Note:/ Language-based printers, such as PostScript
|
|
printers, cannot directly print plain text. The simple
|
|
setup outlined above and described in the following
|
|
sections assumes that if you are installing such a printer
|
|
you will print only files that the printer can understand.
|
|
|
|
Users often expect that they can print plain text to any
|
|
of the printers installed on your system. Programs that
|
|
interface to LPD to do their printing usually make the
|
|
same assumption. If you are installing such a printer and
|
|
want to be able to print jobs in the printer language
|
|
<em/and/ print plain text jobs, you are strongly urged to
|
|
add an additional step to the simple setup outlined above:
|
|
install an automatic plain-text--to--PostScript (or other
|
|
printer language) conversion program. Section <ref
|
|
id="printing:advanced:if-conversion" name="Accommodating
|
|
Plain Text Jobs on PostScript Printers"> tells how to do
|
|
this.
|
|
|
|
<sect3><heading>Naming the Printer<label
|
|
id="printing:naming"></heading>
|
|
|
|
<p> The first (easy) step is to pick a name for your
|
|
printer. It really does not matter whether you choose
|
|
functional or whimsical names since you can also provide
|
|
a number aliases for the printer.
|
|
|
|
At least one of the printers specified in the
|
|
<tt>/etc/printcap</tt> should have the alias
|
|
<tt/lp/. This is the default printer's name. If users
|
|
do not have the PRINTER environment variable nor
|
|
specify a printer name on the command line of any of the
|
|
LPD commands, then <tt/lp/ will be the default printer
|
|
they get to use.
|
|
|
|
Also, it is common practice to make the last alias for a
|
|
printer be a full description of the printer, including
|
|
make and model.
|
|
|
|
Once you have picked a name and some common aliases, put
|
|
them in the <tt>/etc/printcap</tt> file. The name of
|
|
the printer should start in the leftmost column.
|
|
Separate each alias with a vertical bar and put a colon
|
|
after the last alias.
|
|
|
|
In the following example, we start with a skeletal
|
|
<tt>/etc/printcap</tt> that defines two printers (a
|
|
Diablo 630 line printer and a Panasonic KX-P4455
|
|
PostScript laser printer):
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:
|
|
</code>
|
|
In this example, the first printer is named <tt/rattan/
|
|
and has as aliases <tt/line/, <tt/diablo/, <tt/lp/, and
|
|
<tt/Diablo 630 Line Printer/. Since it has the alias
|
|
<tt/lp/, it is also the default printer. The second is
|
|
named <tt/bamboo/, and has as aliases <tt/ps/, <tt/PS/,
|
|
<tt/S/, <tt/panasonic/, and <tt/Panasonic KX-P4455
|
|
PostScript v51.4/.
|
|
|
|
<sect3><heading>Suppressing Header Pages<label
|
|
id="printing:no-header-pages"></heading>
|
|
|
|
<p> The LPD spooling system will by default print a
|
|
<em/header page/ for each job. The header page contains
|
|
the user name who requested the job, the host from which
|
|
the job came, and the name of the job, in nice large
|
|
letters. Unfortunately, all this extra text gets in the
|
|
way of debugging the simple printer setup, so we will
|
|
suppress header pages.
|
|
|
|
To suppress header pages, add the <tt/sh/ capability to
|
|
the entry for the printer in
|
|
<tt>/etc/printcap</tt>. Here is the example
|
|
<tt>/etc/printcap</tt> with <tt/sh/ added:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose - no header pages anywhere
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:
|
|
</code>
|
|
Note how we used the correct format: the first line
|
|
starts in the leftmost column, and subsequent lines are
|
|
indented with a single TAB. Every line in an entry
|
|
except the last ends in a backslash character.
|
|
|
|
<sect3><heading>Making the Spooling Directory<label
|
|
id="printing:spooldir"></heading>
|
|
|
|
<p> The next step in the simple spooler setup is to make a
|
|
<em/spooling directory/, a directory where print jobs
|
|
reside until they are printed, and where a number of
|
|
other spooler support files live.
|
|
|
|
Because of the variable nature of spooling directories,
|
|
it is customary to put these directories under
|
|
<tt>/var/spool</tt>. It is not necessary to backup the
|
|
contents of spooling directories, either. Recreating
|
|
them is as simple as running <tt/mkdir/.
|
|
|
|
It is also customary to make the directory with a name
|
|
that is identical to the name of the printer, as shown
|
|
below:
|
|
<tscreen>
|
|
<tt>mkdir /var/spool/<it>printer-name</it></tt>
|
|
</tscreen>
|
|
However, if you have a lot of printers on your network,
|
|
you might want to put the spooling directories under a
|
|
single directory that you reserve just for printing with
|
|
LPD. We will do this for our two example printers
|
|
<tt/rattan/ and <tt/bamboo/:
|
|
<tscreen><verb>
|
|
mkdir /var/spool/lpd
|
|
mkdir /var/spool/lpd/rattan
|
|
mkdir /var/spool/lpd/bamboo
|
|
</verb></tscreen>
|
|
|
|
<em/Note:/ If you are concerned about the privacy of jobs
|
|
that users print, you might want to protect the spooling
|
|
directory so it is not publicly accessible. Spooling
|
|
directories should be owned and be readable, writable,
|
|
and searchable by user daemon and group daemon, and no
|
|
one else. We will do this for our example printers:
|
|
|
|
<tscreen><verb>
|
|
chown daemon.daemon /var/spool/lpd/rattan
|
|
chown daemon.daemon /var/spool/lpd/bamboo
|
|
chmod 770 /var/spool/lpd/rattan
|
|
chmod 770 /var/spool/lpd/bamboo
|
|
</verb></tscreen>
|
|
|
|
Finally, you need to tell LPD about these directories
|
|
using the <tt>/etc/printcap</tt> file. You specify the
|
|
pathname of the spooling directory with the <tt/sd/
|
|
capability:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose - added spooling directories
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:
|
|
</code>
|
|
Note that the name of the printer starts in the first
|
|
column but all other entries describing the printer
|
|
should be indented with a tab and each line escaped with
|
|
a backslash.
|
|
|
|
If you do not specify a spooling directory with <tt/sd/,
|
|
the spooling system will use <tt>/var/spool/lpd</tt> as
|
|
a default.
|
|
|
|
<sect3><heading>Identifying the Printer Device<label
|
|
id="printing:device"></heading>
|
|
|
|
<p> In section <ref id="printing:dev-ports" name="Adding
|
|
/dev Entries for the Ports">, we identified which
|
|
entry in the <tt>/dev</tt> directory FreeBSD will use
|
|
to communicate with the printer. Now, we tell LPD
|
|
that information. When the spooling system has a job
|
|
to print, it will open the specified device on behalf
|
|
of the filter program (which is responsible for
|
|
passing data to the printer).
|
|
|
|
List the <tt>/dev</tt> entry pathname in the
|
|
<tt>/etc/printcap</tt> file using the <tt/lp/
|
|
capability.
|
|
|
|
In our running example, let us assume that <tt/rattan/ is
|
|
on the first parallel port, and <tt/bamboo/ is on a
|
|
sixth serial port; here are the additions to
|
|
<tt>/etc/printcap</tt>:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose - identified what devices to use
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:\
|
|
:lp=/dev/lpt0:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:\
|
|
:lp=/dev/ttyd5:
|
|
</code>
|
|
|
|
If you do not specify the <tt/lp/ capability for a
|
|
printer in your <tt>/etc/printcap</tt> file, LPD uses
|
|
<tt>/dev/lp</tt> as a default. <tt>/dev/lp</tt>
|
|
currently does not exist in FreeBSD.
|
|
|
|
If the printer you are installing is connected to a
|
|
parallel port, skip to the section <ref name="Installing
|
|
the Text Filter" id="printing:textfilter">. Otherwise,
|
|
be sure to follow the instructions in the next section.
|
|
|
|
<sect3><heading>Configuring Spooler Communication
|
|
Parameters<label id="printing:commparam"></heading>
|
|
|
|
<p> For printers on serial ports, LPD can set up the bps
|
|
rate, parity, and other serial communication parameters
|
|
on behalf of the filter program that sends data to the
|
|
printer. This is advantageous since
|
|
<itemize>
|
|
<item>It lets you try different communication
|
|
parameters by simply editing the
|
|
<tt>/etc/printcap</tt> file; you do not have to
|
|
recompile the filter program.
|
|
|
|
<item>It enables the spooling system to use the same
|
|
filter program for multiple printers which may have
|
|
different serial communication settings.
|
|
</itemize>
|
|
|
|
The following <tt>/etc/printcap</tt> capabilities
|
|
control serial communication parameters of the device
|
|
listed in the <tt/lp/ capability:
|
|
<descrip>
|
|
<tag/<tt>br#<it/bps-rate/</tt>/
|
|
|
|
Sets the communications speed of the device to
|
|
<it/bps-rate/, where <it/bps-rate/ can be 50, 75,
|
|
110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
|
|
4800, 9600, 19200, or 38400 bits-per-second.
|
|
|
|
<tag/<tt>fc#<it/clear-bits/</tt>/
|
|
|
|
Clears the flag bits <it/clear-bits/ in the
|
|
<tt/sgttyb/ structure after opening the device.
|
|
|
|
<tag/<tt>fs#<it/set-bits/</tt>/
|
|
|
|
Sets the flag bits <it/set-bits/ in the <tt/sgttyb/
|
|
structure.
|
|
|
|
<tag/<tt>xc#<it/clear-bits/</tt>/
|
|
|
|
Clears local mode bits <it/clear-bits/ after opening
|
|
the device.
|
|
|
|
<tag/<tt>xs#<it/set-bits/</tt>/
|
|
|
|
Sets local mode bits <it/set-bits/.
|
|
</descrip>
|
|
For more information on the bits for the <tt/fc/,
|
|
<tt/fs/, <tt/xc/, and <tt/xs/ capabilities, see the file
|
|
<tt>/usr/include/sys/ioctl_compat.h</tt>.
|
|
|
|
When LPD opens the device specified by the <tt/lp/
|
|
capability, it reads the flag bits in the <tt/sgttyb/
|
|
structure; it clears any bits in the <tt/fc/ capability,
|
|
then sets bits in the <tt/fs/ capability, then applies
|
|
the resultant setting. It does the same for the local
|
|
mode bits as well.
|
|
|
|
Let us add to our example printer on the sixth serial
|
|
port. We will set the bps rate to 38400. For the flag
|
|
bits, we will set the TANDEM, ANYP, LITOUT, FLUSHO, and
|
|
PASS8 flags. For the local mode bits, we will set the
|
|
LITOUT and PASS8 flags:
|
|
<tscreen><verb>
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:\
|
|
:lp=/dev/ttyd5:fs#0x82000c1:xs#0x820:
|
|
</verb></tscreen>
|
|
|
|
|
|
<sect3><heading>Installing the Text Filter<label
|
|
id="printing:textfilter"></heading>
|
|
|
|
<p> We are now ready to tell LPD what text filter to use to
|
|
send jobs to the printer. A <em/text filter/, also
|
|
known as an <em/input filter/, is a program that LPD
|
|
runs when it has a job to print. When LPD runs the text
|
|
filter for a printer, it sets the filter's standard
|
|
input to the job to print, and its standard output to
|
|
the printer device specified with the <tt/lp/
|
|
capability. The filter is expected to read the job from
|
|
standard input, perform any necessary translation for the
|
|
printer, and write the results to standard output, which
|
|
will get printed. For more information on the text
|
|
filter, see section <ref id="printing:advanced:filters"
|
|
name="Filters">.
|
|
|
|
For our simple printer setup, the text filter can be a
|
|
small shell script that just executes <tt>/bin/cat</tt>
|
|
to send the job to the printer. FreeBSD comes with
|
|
another filter called <tt/lpf/ that handles backspacing
|
|
and underlining for printers that might not deal with
|
|
such character streams well. And, of course, you can
|
|
use any other filter program you want. The filter
|
|
<tt/lpf/ is described in detail in section <ref
|
|
id="printing:advanced:lpf" name="lpf: a Text Filter">.
|
|
|
|
First, let uss make the shell script
|
|
<tt>/usr/local/libexec/if-simple</tt> be a simple text
|
|
filter. Put the following text into that file with your
|
|
favorite text editor:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# if-simple - Simple text input filter for lpd
|
|
# Installed in /usr/local/libexec/if-simple
|
|
#
|
|
# Simply copies stdin to stdout. Ignores all filter arguments.
|
|
|
|
/bin/cat && exit 0
|
|
exit 2
|
|
</code>
|
|
Make the file executable:
|
|
<tscreen><verb>
|
|
chmod 555 /usr/local/libexec/if-simple
|
|
</verb></tscreen>
|
|
|
|
And then tell LPD to use it by specifying it with the
|
|
<tt/if/ capability in <tt>/etc/printcap</tt>. We will add
|
|
it to the two printers we have so far in the example
|
|
<tt>/etc/printcap</tt>:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose - added text filter
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:\
|
|
:lp=/dev/lpt0:\
|
|
:if=/usr/local/libexec/if-simple:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:\
|
|
:lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:\
|
|
:if=/usr/local/libexec/if-simple:
|
|
</code>
|
|
|
|
<sect3><heading>Trying It Out<label id="printing:trying"></heading>
|
|
|
|
<p> You have reached the end of the simple LPD setup.
|
|
Unfortunately, congratulations are not quite yet in
|
|
order, since we still have to test the setup and
|
|
correct any problems. To test the setup, try printing
|
|
something. To print with the LPD system, you use the
|
|
command <tt/lpr/, which submits a job for printing.
|
|
|
|
You can combine <tt/lpr/ with the <tt/lptest/ program,
|
|
introduced in section <ref id="printing:testing"
|
|
name="Checking Printer Communications"> to generate some
|
|
test text.
|
|
|
|
<bf>To test the simple LPD setup:</bf>
|
|
|
|
<p> Type:
|
|
<tscreen>
|
|
<tt>lptest 20 5 | lpr -P<it/printer-name/</tt>
|
|
</tscreen>
|
|
where <it/printer-name/ is a the name of a printer (or
|
|
an alias) specified in <tt>/etc/printcap</tt>. To test
|
|
the default printer, type <tt/lpr/ without any <tt/-P/
|
|
argument. Again, if you are testing a printer that
|
|
expects PostScript, send a PostScript program in that
|
|
language instead of using <tt/lptest/. You can do so by
|
|
putting the program in a file and typing <tt/lpr
|
|
<it/file//.
|
|
|
|
For a PostScript printer, you should get the results
|
|
of the program. If you are using <tt/lptest/, then your
|
|
results should look like the following:
|
|
|
|
<tscreen><verb>
|
|
!"#$%&'()*+,-./01234
|
|
"#$%&'()*+,-./012345
|
|
#$%&'()*+,-./0123456
|
|
$%&'()*+,-./01234567
|
|
%&'()*+,-./012345678
|
|
</verb></tscreen>
|
|
|
|
To further test the printer, try downloading larger
|
|
programs (for language-based printers) or running
|
|
<tt/lptest/ with different arguments. For example,
|
|
<tt/lptest 80 60/ will produce 60 lines of 80 characters
|
|
each.
|
|
|
|
If the printer did not work, see the next section, <ref
|
|
id="printing:troubleshooting" name="Troubleshooting">.
|
|
|
|
<sect3><heading>Troubleshooting<label
|
|
id="printing:troubleshooting"></heading>
|
|
|
|
<p> After performing the simple test with <tt/lptest/, you
|
|
might have gotten one of the following results instead of
|
|
the correct printout:
|
|
<descrip>
|
|
<tag/It worked, after awhile; or, it did not eject a full sheet./
|
|
|
|
The printer printed the above, but it sat for awhile
|
|
and did nothing. In fact, you might have needed to
|
|
press a PRINT REMAINING or FORM FEED button on the
|
|
printer to get any results to appear.
|
|
|
|
If this is the case, the printer was probably
|
|
waiting to see if there was any more data for your
|
|
job before it printed anything. To fix this
|
|
problem, you can have the text filter send a FORM
|
|
FEED character (or whatever is necessary) to the
|
|
printer. This is usually sufficient to have the
|
|
printer immediately print any text remaining in its
|
|
internal buffer. It is also useful to make sure each
|
|
print job ends on a full sheet, so the next job
|
|
does not start somewhere on the middle of the last
|
|
page of the previous job.
|
|
|
|
The following replacement for the shell script
|
|
<tt>/usr/local/libexec/if-simple</tt> prints a form
|
|
feed after it sends the job to the printer:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# if-simple - Simple text input filter for lpd
|
|
# Installed in /usr/local/libexec/if-simple
|
|
#
|
|
# Simply copies stdin to stdout. Ignores all filter arguments.
|
|
# Writes a form feed character (\f) after printing job.
|
|
|
|
/bin/cat && printf "\f" && exit 0
|
|
exit 2
|
|
</code>
|
|
|
|
<tag/It produced the ``staircase effect.''/
|
|
|
|
You got the following on paper:
|
|
<tscreen><verb>
|
|
!"#$%&'()*+,-./01234
|
|
"#$%&'()*+,-./012345
|
|
#$%&'()*+,-./0123456
|
|
</verb></tscreen>
|
|
You have become another victim of the <em/staircase
|
|
effect/, caused by conflicting interpretations of
|
|
what characters should indicate a new-line.
|
|
UNIX-style operating systems use a single character:
|
|
ASCII code 10, the line feed (LF). MS-DOS, OS/2,
|
|
and others uses a pair of characters, ASCII code 10
|
|
<em/and/ ASCII code 13 (the carriage return or CR).
|
|
Many printers use the MS-DOS convention for
|
|
representing new-lines.
|
|
|
|
When you print with FreeBSD, your text used just the
|
|
line feed character. The printer, upon seeing a
|
|
line feed character, advanced the paper one line,
|
|
but maintained the same horizontal position on the
|
|
page for the next character to print. That is what
|
|
the carriage return is for: to move the location of
|
|
the next character to print to the left edge of the
|
|
paper.
|
|
|
|
Here is what FreeBSD wants your printer to do:
|
|
<tscreen><verb>
|
|
Printer received CR Printer prints CR
|
|
Printer received LF Printer prints CR + LF
|
|
</verb></tscreen>
|
|
|
|
Here are some ways to achieve this:
|
|
<itemize>
|
|
<item>Use the printer's configuration switches or
|
|
control panel to alter its interpretation of
|
|
these characters. Check your printer's manual
|
|
to find out how to do this.
|
|
|
|
<p> <em/Note:/ If you boot your system into
|
|
other operating systems besides FreeBSD, you
|
|
may have to <em/reconfigure/ the printer to
|
|
use a an interpretation for CR and LF
|
|
characters that those other operating systems
|
|
use. You might prefer one of the other
|
|
solutions, below.
|
|
|
|
<item>Have FreeBSD's serial line driver
|
|
automatically convert LF to CR+LF. Of course,
|
|
this works with printers on serial ports
|
|
<em/only/. To enable this feature, set the
|
|
CRMOD bit in <tt/fs/ capability in the
|
|
<tt>/etc/printcap</tt> file for the printer.
|
|
|
|
<item>Send an <em/escape code/ to the printer to
|
|
have it temporarily treat LF characters
|
|
differently. Consult your printer's manual for
|
|
escape codes that your printer might support.
|
|
When you find the proper escape code, modify the
|
|
text filter to send the code first, then send
|
|
the print job.
|
|
|
|
<p> Here is an example text filter for printers
|
|
that understand the Hewlett-Packard PCL escape
|
|
codes. This filter makes the printer treat LF
|
|
characters as a LF and CR; then it sends the
|
|
job; then it sends a form feed to eject the
|
|
last page of the job. It should work with
|
|
nearly all Hewlett Packard printers.
|
|
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# hpif - Simple text input filter for lpd for HP-PCL based printers
|
|
# Installed in /usr/local/libexec/hpif
|
|
#
|
|
# Simply copies stdin to stdout. Ignores all filter arguments.
|
|
# Tells printer to treat LF as CR+LF. Writes a form feed character
|
|
# after printing job.
|
|
|
|
printf "\033&k2G" && cat && printf "\f" && exit 0
|
|
exit 2
|
|
</code>
|
|
|
|
Here is an example <tt>/etc/printcap</tt> from
|
|
a host called orchid. It has a single printer
|
|
attached to its first parallel port, a Hewlett
|
|
Packard LaserJet 3Si named <tt/teak/. It is
|
|
using the above script as its text filter:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host orchid
|
|
#
|
|
teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\
|
|
:lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\
|
|
:if=/usr/local/libexec/hpif:
|
|
</code>
|
|
</itemize>
|
|
|
|
<tag/It overprinted each line./
|
|
|
|
The printer never advanced a line. All of the lines
|
|
of text were printed on top of each other on one
|
|
line.
|
|
|
|
This problem is the ``opposite'' of the staircase
|
|
effect, described above, and is much rarer.
|
|
Somewhere, the LF characters that FreeBSD uses to
|
|
end a line are being treated as CR characters to
|
|
return the print location to the left edge of the
|
|
paper, but not also down a line.
|
|
|
|
Use the printer's configuration switches or control
|
|
panel to enforce the following interpretation of LF
|
|
and CR characters:
|
|
<tscreen><verb>
|
|
Printer received CR Printer prints CR
|
|
Printer received LF Printer prints CR + LF
|
|
</verb></tscreen>
|
|
|
|
<tag/The printer lost characters./
|
|
|
|
While printing, the printer did nott print a few
|
|
characters in each line. The problem might have
|
|
gotten worse as the printer ran, losing more and
|
|
more characters.
|
|
|
|
The problem is that the printer cannot keep up with
|
|
the speed at which the computer sends data over a
|
|
serial line. (This problem should not occur with
|
|
printers on parallel ports.) There are two ways to
|
|
overcome the problem:
|
|
<itemize>
|
|
<item>If the printer supports XON/XOFF flow
|
|
control, have FreeBSD use it by specifying the
|
|
TANDEM bit in the <tt/fs/ capability.
|
|
|
|
<item>If the printer supports carrier flow
|
|
control, specify the MDMBUF bit in the <tt/fs/
|
|
capability. Make sure the cable connecting the
|
|
printer to the computer is correctly wired for
|
|
carrier flow control.
|
|
|
|
<item>If the printer does not support any flow
|
|
control, use some combination of the NLDELAY,
|
|
TBDELAY, CRDELAY, VTDELAY, and BSDELAY bits in
|
|
the <tt/fs/ capability to add appropriate delays
|
|
to the stream of data sent to the printer.
|
|
</itemize>
|
|
|
|
<tag/It printed garbage./
|
|
|
|
The printer printed what appeared to be random
|
|
garbage, but not the desired text.
|
|
|
|
This is usually another symptom of incorrect
|
|
communications parameters with a serial printer.
|
|
Double-check the bps rate in the <tt/br/ capability,
|
|
and the parity bits in the <tt/fs/ and <tt/fc/
|
|
capabilities; make sure the printer is using the
|
|
same settings as specified in the
|
|
<tt>/etc/printcap</tt> file.
|
|
|
|
<tag/Nothing happened./
|
|
|
|
If nothing happened, the problem is probably within
|
|
FreeBSD and not the hardware. Add the log file
|
|
(<tt/lf/) capability to the entry for the printer
|
|
you are debugging in the <tt>/etc/printcap</tt> file.
|
|
For example, here is the entry for <tt/rattan/, with
|
|
the <tt/lf/ capability:
|
|
<tscreen><verb>
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:\
|
|
:lp=/dev/lpt0:\
|
|
:if=/usr/local/libexec/if-simple:\
|
|
:lf=/var/log/rattan.log
|
|
</verb></tscreen>
|
|
Then, try printing again. Check the log file (in
|
|
our example, <tt>/var/log/rattan.log</tt>) to see
|
|
any error messages that might appear. Based on the
|
|
messages you see, try to correct the problem.
|
|
|
|
If you do not specify a <tt/lf/ capability, LPD uses
|
|
<tt>/dev/console</tt> as a default.
|
|
</descrip>
|
|
|
|
<sect><heading>Using Printers<label id="printing:using"></heading>
|
|
|
|
<p> This section tells you how to use printers you have setup with
|
|
FreeBSD. Here is an overview of the user-level commands:
|
|
<descrip>
|
|
<tag/<tt/lpr//
|
|
Print jobs
|
|
|
|
<tag/<tt/lpq//
|
|
Check printer queues
|
|
|
|
<tag/<tt/lprm//
|
|
Remove jobs from a printer's queue
|
|
|
|
</descrip>
|
|
|
|
There is also an administrative command, <tt/lpc/, described in
|
|
the section <ref id="printing:lpc" name="Administrating the
|
|
LPD Spooler">, used to control printers and their queues.
|
|
|
|
All three of the commands <tt/lpr/, <tt/lprm/, and <tt/lpq/
|
|
accept an option ``<tt/-P/ <it/printer-name/'' to specify on
|
|
which printer/queue to operate, as listed in the
|
|
<tt>/etc/printcap</tt> file. This enables you to submit,
|
|
remove, and check on jobs for various printers. If you do not
|
|
use the <tt/-P/ option, then these commands use the printer
|
|
specified in the PRINTER environment variable. Finally, if
|
|
you do not have a PRINTER environment variable, these commands
|
|
default to the printer named <tt/lp/.
|
|
|
|
Hereafter, the terminology <em/default printer/ means the
|
|
printer named in the PRINTER environment variable, or the
|
|
printer named <tt/lp/ when there is no PRINTER environment
|
|
variable.
|
|
|
|
<sect1><heading>Printing Jobs<label id="printing:lpr"></heading>
|
|
<p>
|
|
|
|
To print files, type
|
|
<tscreen>
|
|
<tt>lpr <it/filename.../</tt>
|
|
</tscreen>
|
|
This prints each of the listed files to the default printer.
|
|
If you list no files, <tt/lpr/ reads data to print from
|
|
standard input. For example, this command prints some
|
|
important system files:
|
|
<tscreen><verb>
|
|
lpr /etc/host.conf /etc/hosts.equiv
|
|
</verb></tscreen>
|
|
To select a specific printer, type
|
|
<tscreen>
|
|
<tt>lpr -P <it/printer-name/ <it/filename.../</tt>
|
|
</tscreen>
|
|
This example prints a long listing of the current directory
|
|
to the printer named <tt/rattan/:
|
|
<tscreen><verb>
|
|
ls -l | lpr -P rattan
|
|
</verb></tscreen>
|
|
Because no files were listed for the <tt/lpr/ command,
|
|
<tt/lpr/ read the data to print from standard input, which
|
|
was the output of the <tt/ls -l/ command.
|
|
|
|
The <tt/lpr/ command can also accept a wide variety of
|
|
options to control formatting, apply file conversions,
|
|
generate multiple copies, and so forth. For more
|
|
information, see the section <ref id="printing:lpr:options"
|
|
name="Printing Options">.
|
|
|
|
<sect1><heading>Checking Jobs<label id="printing:lpq"></heading>
|
|
|
|
<p> When you print with <tt/lpr/, the data you wish to print
|
|
is put together in a package called a <em/print job/, which
|
|
is sent to the LPD spooling system. Each printer has a
|
|
queue of jobs, and your job waits in that queue along with
|
|
other jobs from yourself and from other users. The printer
|
|
prints those jobs in a first-come, first-served order.
|
|
|
|
To display the queue for the default printer, type <tt/lpq/.
|
|
For a specific printer, use the <tt/-P/ option. For
|
|
example, the command
|
|
<tscreen><verb>
|
|
lpq -P bamboo
|
|
</verb></tscreen>
|
|
shows the queue for the printer named <tt/bamboo/. Here is
|
|
an example of the output of the <tt/lpq/ command:
|
|
<tscreen><verb>
|
|
bamboo is ready and printing
|
|
Rank Owner Job Files Total Size
|
|
active kelly 9 /etc/host.conf, /etc/hosts.equiv 88 bytes
|
|
2nd kelly 10 (standard input) 1635 bytes
|
|
3rd mary 11 ... 78519 bytes
|
|
</verb></tscreen>
|
|
This shows three jobs in the queue for <tt/bamboo/. The
|
|
first job, submitted by user kelly, got assigned <em/job
|
|
number/ 9. Every job for a printer gets a unique job
|
|
number. Most of the time you can ignore the job number, but
|
|
you will need it if you want to cancel the job; see section
|
|
<ref id="printing:lprm" name="Removing Jobs"> for details.
|
|
|
|
Job number nine consists of two files; multiple files given
|
|
on the <tt/lpr/ command line are treated as part of a single
|
|
job. It is the currently active job (note the word
|
|
<tt/active/ under the ``Rank'' column), which means the
|
|
printer should be currently printing that job. The second
|
|
job consists of data passed as the standard input to the
|
|
<tt/lpr/ command. The third job came from user mary; it is a
|
|
much larger job. The pathname of the files she's trying to
|
|
print is too long to fit, so the <tt/lpq/ command just shows
|
|
three dots.
|
|
|
|
The very first line of the output from <tt/lpq/ is also
|
|
useful: it tells what the printer is currently doing (or at
|
|
least what LPD thinks the printer is doing).
|
|
|
|
The <tt/lpq/ command also support a <tt/-l/ option to
|
|
generate a detailed long listing. Here is an example of
|
|
<tt/lpq -l/:
|
|
<tscreen><verb>
|
|
waiting for bamboo to become ready (offline ?)
|
|
|
|
kelly: 1st [job 009rose]
|
|
/etc/host.conf 73 bytes
|
|
/etc/hosts.equiv 15 bytes
|
|
|
|
kelly: 2nd [job 010rose]
|
|
(standard input) 1635 bytes
|
|
|
|
mary: 3rd [job 011rose]
|
|
/home/orchid/mary/research/venus/alpha-regio/mapping 78519 bytes
|
|
</verb></tscreen>
|
|
|
|
<sect1><heading>Removing Jobs<label
|
|
id="printing:lprm"></heading>
|
|
|
|
<p> If you change your mind about printing a job, you can
|
|
remove the job from the queue with the <tt/lprm/ command.
|
|
Often, you can even use <tt/lprm/ to remove an active job,
|
|
but some or all of the job might still get printed.
|
|
|
|
To remove a job from the default printer, first use <tt/lpq/
|
|
to find the job number. Then type
|
|
<tscreen>
|
|
<tt/lprm <it/job-number//
|
|
</tscreen>
|
|
To remove the job from a specific printer, add the <tt/-P/
|
|
option. The following command removes job number 10 from
|
|
the queue for the printer <tt/bamboo/:
|
|
<tscreen><verb>
|
|
lprm -P bamboo 10
|
|
</verb></tscreen>
|
|
The <tt/lprm/ command has a few shortcuts:
|
|
<descrip>
|
|
<tag/lprm -/
|
|
|
|
Removes all jobs (for the default printer) belonging to
|
|
you.
|
|
|
|
<tag/lprm <it/user//
|
|
|
|
Removes all jobs (for the default printer) belonging to
|
|
<it/user/. The superuser can remove other users' jobs;
|
|
you can remove only your own jobs.
|
|
|
|
<tag/lprm/
|
|
|
|
With no job number, user name, or ``<tt/-/'' appearing
|
|
on the command line, <tt/lprm/ removes the currently
|
|
active job on the default printer, if it belongs to
|
|
you. The superuser can remove any active job.
|
|
</descrip>
|
|
|
|
Just use the <tt/-P/ option with the above shortcuts to
|
|
operate on a specific printer instead of the default. For
|
|
example, the following command removes all jobs for the
|
|
current user in the queue for the printer named <tt/rattan/:
|
|
|
|
<tscreen><verb>
|
|
lprm -P rattan -
|
|
</verb></tscreen>
|
|
|
|
<em/Note:/ If you are working in a networked environment,
|
|
<tt/lprm/ will let you remove jobs only from the host from
|
|
which the jobs were submitted, even if the same printer is
|
|
available from other hosts. The following command sequence
|
|
demonstrates this:
|
|
<code>
|
|
rose% lpr -P rattan myfile
|
|
rose% rlogin orchid
|
|
orchid% lpq -P rattan
|
|
Rank Owner Job Files Total Size
|
|
active seeyan 12 ... 49123 bytes
|
|
2nd kelly 13 myfile 12 bytes
|
|
orchid% lprm -P rattan 13
|
|
rose: Permission denied
|
|
orchid% logout
|
|
rose% lprm -P rattan 13
|
|
dfA013rose dequeued
|
|
cfA013rose dequeued
|
|
rose%
|
|
</code>
|
|
|
|
<sect1><heading>Beyond Plain Text: Printing Options<label
|
|
id="printing:lpr:options"></heading>
|
|
|
|
<p> The <tt/lpr/ command supports a number of options that
|
|
control formatting text, converting graphic and other file
|
|
formats, producing multiple copies, handling of the job, and
|
|
more. This section describes the options.
|
|
|
|
<sect2><heading>Formatting and Conversion Options<label
|
|
id="printing:lpr:options:format"></heading>
|
|
|
|
<p> The following <tt/lpr/ options control formatting of the
|
|
files in the job. Use these options if the job does not
|
|
contain plain text or if you want plain text formatted
|
|
through the <tt/pr/ utility.
|
|
|
|
For example, the following command prints a DVI file (from
|
|
the TeX typesetting system) named <tt/fish-report.dvi/
|
|
to the printer named <tt/bamboo/:
|
|
<tscreen><verb>
|
|
lpr -P bamboo -d fish-report.dvi
|
|
</verb></tscreen>
|
|
These options apply to every file in the job, so you cannot
|
|
mix (say) DVI and ditroff files together in a job.
|
|
Instead, submit the files as separate jobs, using a
|
|
different conversion option for each job.
|
|
|
|
<em/Note:/ All of these options except <tt/-p/ and <tt/-T/
|
|
require conversion filters installed for the destination
|
|
printer. For example, the <tt/-d/ option requires the DVI
|
|
conversion filter. Section <ref
|
|
id="printing:advanced:convfilters" name="Conversion
|
|
Filters"> gives details.
|
|
|
|
<descrip>
|
|
<tag/<tt/-c// Print cifplot files.
|
|
|
|
<tag/<tt/-d// Print DVI files.
|
|
|
|
<tag/<tt/-f// Print FORTRAN text files.
|
|
|
|
<tag/<tt/-g// Print plot data.
|
|
|
|
<tag/<tt/-i <it/number///
|
|
|
|
Indent the output by <it/number/ columns; if you omit
|
|
<it/number/, indent by 8 columns. This option works
|
|
only with certain conversion filters.
|
|
|
|
<em/Note:/ Do not put any space between the <tt/-i/ and
|
|
the number.
|
|
|
|
<tag/<tt/-l//
|
|
|
|
Print literal text data, including control characters.
|
|
|
|
<tag/<tt/-n// Print ditroff (device independent troff) data.
|
|
|
|
<tag/-p/
|
|
|
|
Format plain text with <tt/pr/ before printing. See
|
|
pr(1) for more information.
|
|
|
|
<tag/<tt/-T <it/title///
|
|
|
|
Use <it/title/ on the <tt/pr/ header instead of the
|
|
file name. This option has effect only when used with
|
|
the <tt/-p/ option.
|
|
|
|
<tag/<tt/-t// Print troff data.
|
|
|
|
<tag/<tt/-v// Print raster data.
|
|
|
|
</descrip>
|
|
|
|
Here is an example: this command prints a nicely
|
|
formatted version of the <tt/ls/ manual page on the
|
|
default printer:
|
|
<tscreen><verb>
|
|
zcat /usr/share/man/man1/ls.1.gz | troff -t -man | lpr -t
|
|
</verb></tscreen>
|
|
The <tt/zcat/ command uncompresses the source of the
|
|
<tt/ls/ manual page and passes it to the <tt/troff/
|
|
command, which formats that source and makes GNU troff
|
|
output and passes it to <tt/lpr/, which submits the job to
|
|
the LPD spooler. Because we used the <tt/-t/ option to
|
|
<tt/lpr/, the spooler will convert the GNU troff output
|
|
into a format the default printer can understand when it
|
|
prints the job.
|
|
|
|
<sect2><heading>Job Handling Options<label
|
|
id="printing:lpr:options:job-handling"></heading>
|
|
|
|
<p> The following options to <tt/lpr/ tell LPD to handle the
|
|
job specially:
|
|
|
|
<descrip>
|
|
<tag/-# <it/copies//
|
|
|
|
Produce a number of <it/copies/ of each file in the
|
|
job instead of just one copy. An administrator may
|
|
disable this option to reduce printer wear-and-tear
|
|
and encourage photocopier usage. See section <ref
|
|
id="printing:advanced:restricting:copies"
|
|
name="Restricting Multiple Copies">.
|
|
|
|
<p> This example prints three copies of <tt/parser.c/
|
|
followed by three copies of <tt/parser.h/ to the
|
|
default printer:
|
|
<tscreen><verb>
|
|
lpr -#3 parser.c parser.h
|
|
</verb></tscreen>
|
|
|
|
<tag/-m/
|
|
|
|
Send mail after completing the print job. With this
|
|
option, the LPD system will send mail to your account
|
|
when it finishes handling your job. In its message,
|
|
it will tell you if the job completed successfully or
|
|
if there was an error, and (often) what the error was.
|
|
|
|
<tag/-s/ Do not copy the files to the spooling directory,
|
|
but make symbolic links to them instead.
|
|
|
|
If you are printing a large job, you probably want to
|
|
use this option. It saves space in the spooling
|
|
directory (your job might overflow the free space on
|
|
the filesystem where the spooling directory resides).
|
|
It saves time as well since LPD will not have to copy
|
|
each and every byte of your job to the spooling
|
|
directory.
|
|
|
|
There is a drawback, though: since LPD will refer to
|
|
the original files directly, you cannot modify or
|
|
remove them until they have been printed.
|
|
|
|
<em/Note:/ If you are printing to a remote printer, LPD
|
|
will eventually have to copy files from the local host
|
|
to the remote host, so the <tt/-s/ option will save
|
|
space only on the local spooling directory, not the
|
|
remote. It is still useful, though.
|
|
|
|
<tag/-r/
|
|
|
|
Remove the files in the job after copying them to the
|
|
spooling directory, or after printing them with the
|
|
<tt/-s/ option. Be careful with this option!
|
|
|
|
</descrip>
|
|
|
|
<sect2><heading>Header Page Options<label
|
|
id="printing:lpr:options:misc"></heading>
|
|
|
|
<p> These options to <tt/lpr/ adjust the text that normally
|
|
appears on a job's header page. If header pages are
|
|
suppressed for the destination printer, these options have
|
|
no effect. See section <ref name="Header Pages"
|
|
id="printing:advanced:header-pages"> for information about
|
|
setting up header pages.
|
|
|
|
<descrip>
|
|
<tag/-C <it/text//
|
|
|
|
Replace the hostname on the header page with
|
|
<it/text/. The hostname is normally the name of the
|
|
host from which the job was submitted.
|
|
|
|
<tag/-J <it/text//
|
|
|
|
Replace the job name on the header page with
|
|
<it/text/. The job name is normally the name of the
|
|
first file of the job, or ``stdin'' if you are printing
|
|
standard input.
|
|
|
|
<tag/-h/
|
|
|
|
Do not print any header page. <em/Note:/ At some
|
|
sites, this option may have no effect due to the way
|
|
header pages are generated. See <ref name="Header
|
|
Pages" id="printing:advanced:header-pages"> for
|
|
details.
|
|
|
|
</descrip>
|
|
|
|
<sect1><heading>Administrating Printers<label
|
|
id="printing:lpc"></heading>
|
|
|
|
<p> As an administrator for your printers, you have had to
|
|
install, set up, and test them. Using the <tt/lpc/ command,
|
|
you can interact with your printers in yet more ways. With
|
|
<tt/lpc/, you can
|
|
|
|
<itemize>
|
|
<item>Start and stop the printers
|
|
|
|
<item>Enable and disable their queues
|
|
|
|
<item>Rearrange the order of the jobs in each queue.
|
|
</itemize>
|
|
|
|
First, a note about terminology: if a printer is
|
|
<em/stopped/, it will not print anything in its queue. Users
|
|
can still submit jobs, which will wait in the queue until
|
|
the printer is <em/started/ or the queue is cleared.
|
|
|
|
If a queue is <em/disabled/, no user (except root) can
|
|
submit jobs for the printer. An <em/enabled/ queue allows
|
|
jobs to be submitted. A printer can be <em/started/ for a
|
|
disabled queue, in which case it will continue to print jobs
|
|
in the queue until the queue is empty.
|
|
|
|
In general, you have to have root privileges to use the
|
|
<tt/lpc/ command. Ordinary users can use the <tt/lpc/
|
|
command to get printer status and to restart a hung printer
|
|
only.
|
|
|
|
Here is a summary of the <tt/lpc/ commands. Most of the
|
|
commands takes a <it/printer-name/ argument to tell on which
|
|
printer to operate. You can use <tt/all/ for the
|
|
<it/printer-name/ to mean all printers listed in
|
|
<tt>/etc/printcap</tt>.
|
|
|
|
<descrip>
|
|
<tag/<tt/abort <it/printer-name///
|
|
|
|
Cancel the current job and stop the printer. Users can
|
|
still submit jobs if the queue's enabled.
|
|
|
|
<tag/<tt/clean <it/printer-name///
|
|
|
|
Remove old files from the printer's spooling directory.
|
|
Occasionally, the files that make up a job are not
|
|
properly removed by LPD, particularly if there have been
|
|
errors during printing or a lot of administrative
|
|
activity. This command finds files that do not belong in
|
|
the spooling directory and removes them.
|
|
|
|
<tag/<tt/disable <it/printer-name///
|
|
|
|
Disable queuing of new jobs. If the printer's started,
|
|
it will continue to print any jobs remaining in the
|
|
queue. The superuser (root) can always submit jobs,
|
|
even to a disabled queue.
|
|
|
|
This command is useful while you are testing a new
|
|
printer or filter installation: disable the queue and
|
|
submit jobs as root. Other users will not be able to
|
|
submit jobs until you complete your testing and re-enable
|
|
the queue with the <tt/enable/ command.
|
|
|
|
<tag/<tt/down <it/printer-name/ <it/message...///
|
|
|
|
Take a printer down. Equivalent to <tt/disable/
|
|
followed by <tt/stop/. The <it/message/ appears as the
|
|
printer's status whenever a user checks the printer's
|
|
queue with <tt/lpq/ or status with <tt/lpc status/.
|
|
|
|
<tag/<tt/enable <it/printer-name///
|
|
|
|
Enable the queue for a printer. Users can submit jobs
|
|
but the printer will not print anything until it is started.
|
|
|
|
<tag/<tt/help <it/command-name///
|
|
|
|
Print help on the command <it/command-name/. With no
|
|
<it/command-name/, print a summary of the commands
|
|
available.
|
|
|
|
<tag/<tt/restart <it/printer-name///
|
|
|
|
Start the printer. Ordinary users can use this command
|
|
if some extraordinary circumstance hangs LPD, but they
|
|
cannot start a printer stopped with either the <tt/stop/
|
|
or <tt/down/ commands. The <tt/restart/ command is
|
|
equivalent to <tt/abort/ followed by <tt/start/.
|
|
|
|
<tag/<tt/start <it/printer-name///
|
|
|
|
Start the printer. The printer will print jobs in its
|
|
queue.
|
|
|
|
<tag/<tt/stop <it/printer-name///
|
|
|
|
Stop the printer. The printer will finish the current
|
|
job and will not print anything else in its queue. Even
|
|
though the printer is stopped, users can still submit
|
|
jobs to an enabled queue.
|
|
|
|
<tag/<tt/topq <it/printer-name/ <it/job-or-username...///
|
|
|
|
Rearrange the queue for <it/printer-name/ by placing the
|
|
jobs with the listed <it/job/ numbers or the jobs
|
|
belonging to <it/username/ at the top of the queue. For
|
|
this command, you cannot use <tt/all/ as the
|
|
<it/printer-name/.
|
|
|
|
<tag/<tt/up <it/printer-name///
|
|
|
|
Bring a printer up; the opposite of the <tt/down/
|
|
command. Equivalent to <tt/start/ followed by
|
|
<tt/enable/.
|
|
|
|
</descrip>
|
|
|
|
<tt/lpc/ accepts the above commands on the command line. If
|
|
you do not enter any commands, <tt/lpc/ enters an interactive
|
|
mode, where you can enter commands until you type <tt/exit/,
|
|
<tt/quit/, or end-of-file.
|
|
|
|
<sect><heading>Advanced Printer Setup<label
|
|
id="printing:advanced"></heading>
|
|
|
|
<p> This section describes filters for printing specially
|
|
formatted files, header pages, printing across networks, and
|
|
restricting and accounting for printer usage.
|
|
|
|
<sect1><heading>Filters<label
|
|
id="printing:advanced:filter-intro"></heading>
|
|
|
|
<p> Although LPD handles network protocols, queuing, access
|
|
control, and other aspects of printing, most of the
|
|
<em/real/ work happens in the <em/filters/. Filters are
|
|
programs that communicate with the printer and handle its
|
|
device dependencies and special requirements. In the simple
|
|
printer setup, we installed a plain text filter---an
|
|
extremely simple one that should work with most printers
|
|
(section <ref id="printing:textfilter" name="Installing the
|
|
Text Filter">).
|
|
|
|
However, in order to take advantage of format conversion,
|
|
printer accounting, specific printer quirks, and so on, you
|
|
should understand how filters work. It will ultimately be
|
|
the filter's responsibility to handle these aspects. And the
|
|
bad news is that most of the time <em/you/ have to provide
|
|
filters yourself. The good news is that many are generally
|
|
available; when they are not, they are usually easy to write.
|
|
|
|
Also, FreeBSD comes with one, <tt>/usr/libexec/lpr/lpf</tt>,
|
|
that works with many printers that can print plain text.
|
|
(It handles backspacing and tabs in the file, and does
|
|
accounting, but that is about all it does.) There are also
|
|
several filters and filter components in the FreeBSD ports
|
|
collection.
|
|
|
|
Here is what you will find in this section:
|
|
|
|
<itemize>
|
|
<item>Section <ref id="printing:advanced:filters"
|
|
name="How Fitlers Work">, tries to give an overview of a
|
|
filter's role in the printing process. You should read
|
|
this section to get an understanding of what is happening
|
|
``under the hood'' when LPD uses filters. This
|
|
knowledge could help you anticipate and debug problems
|
|
you might encounter as you install more and more filters
|
|
on each of your printers.
|
|
|
|
<item>LPD expects every printer to be able to print plain
|
|
text by default. This presents a problem for PostScript
|
|
(or other language-based printers) which cannot directly
|
|
print plain text. Section <ref
|
|
id="printing:advanced:if-conversion" name="Accommodating
|
|
Plain Text Jobs on PostScript Printers"> tells you what
|
|
you should do to overcome this problem. I recommend
|
|
reading this section if you have a PostScript printer.
|
|
|
|
<item>PostScript is a popular output format for many
|
|
programs. Even some people (myself included) write
|
|
PostScript code directly. But PostScript printers are
|
|
expensive. Section <ref id="printing:advanced:ps"
|
|
name="Simulating PostScript on Non-PostScript Printers">
|
|
tells how you can further modify a printer's text filter
|
|
to accept and print PostScript data on a
|
|
<em/non-PostScript/ printer. I recommend reading this
|
|
section if you do not have a PostScript printer.
|
|
|
|
<item>Section <ref id="printing:advanced:convfilters"
|
|
name="Conversion Filters"> tells about a way you can
|
|
automate the conversion of specific file formats, such
|
|
as graphic or typesetting data, into formats your
|
|
printer can understand. After reading this section,
|
|
you should be able to set up your printers such that
|
|
users can type <tt/lpr -t/ to print troff data, or
|
|
<tt/lpr -d/ to print TeX DVI data, or <tt/lpr -v/ to
|
|
print raster image data, and so forth. I recommend
|
|
reading this section.
|
|
|
|
<item>Section <ref id="printing:advanced:of" name="Output
|
|
Filters"> tells all about a not often used feature of
|
|
LPD: output filters. Unless you are printing header
|
|
pages (see <ref id="printing:advanced:header-pages"
|
|
name="Header Pages">), you can probably skip that
|
|
section altogether.
|
|
|
|
<item>Section <ref id="printing:advanced:lpf" name="lpf:
|
|
a Text Filter"> describes <tt/lpf/, a fairly complete
|
|
if simple text filter for line printers (and laser
|
|
printers that act like line printers) that comes with
|
|
FreeBSD. If you need a quick way to get printer
|
|
accounting working for plain text, or if you have a
|
|
printer which emits smoke when it sees backspace
|
|
characters, you should definitely consider <tt/lpf/.
|
|
</itemize>
|
|
|
|
<sect2><heading>How Filters Work<label
|
|
id="printing:advanced:filters"></heading>
|
|
|
|
<p> As mentioned before, a filter is an executable program
|
|
started by LPD to handle the device-dependent part of
|
|
communicating with the printer.
|
|
|
|
When LPD wants to print a file in a job, it starts a
|
|
filter program. It sets the filter's standard input to
|
|
the file to print, its standard output to the printer, and
|
|
its standard error to the error logging file (specified in
|
|
the <tt/lf/ capability in <tt>/etc/printcap</tt>, or
|
|
<tt>/dev/console</tt> by default).
|
|
|
|
Which filter LPD starts and the filter's arguments depend
|
|
on what is listed in the <tt>/etc/printcap</tt> file and
|
|
what arguments the user specified for the job on the
|
|
<tt/lpr/ command line. For example, if the user typed
|
|
<tt/lpr -t/, LPD would start the troff filter, listed in
|
|
the <tt/tf/ capability for the destination printer. If
|
|
the user wanted to print plain text, it would start the
|
|
<tt/if/ filter (this is mostly true: see <ref
|
|
id="printing:advanced:of" name="Output Filters"> for
|
|
details).
|
|
|
|
There are three kinds filters you can specify in
|
|
<tt>/etc/printcap</tt>:
|
|
<itemize>
|
|
<item>The <em/text filter/, confusingly called the
|
|
<em/input filter/ in LPD documentation, handles
|
|
regular text printing. Think of it as the default
|
|
filter. LPD expects every printer to be able to print
|
|
plain text by default, and it is the text filter's job
|
|
to make sure backspaces, tabs, or other special
|
|
characters do not confuse the printer.
|
|
|
|
If you are in an environment where you have to account
|
|
for printer usage, the text filter must also account
|
|
for pages printed, usually by counting the number of
|
|
lines printed and comparing that to the number of
|
|
lines per page the printer supports.
|
|
|
|
The text filter is started with the following argument
|
|
list:
|
|
<tscreen>
|
|
<tt>[-c] -w<it/width/ -l<it/length/ -i<it/indent/ -n <it/login/ -h <it/host/ <it/acct-file/</tt>
|
|
</tscreen>
|
|
where
|
|
<descrip>
|
|
<tag/<tt/-c//
|
|
|
|
appears if the job's submitted with <tt/lpr -l/
|
|
|
|
<tag/<tt/<it/width///
|
|
|
|
is the value from the <tt/pw/ (page width)
|
|
capability specified in <tt>/etc/printcap</tt>,
|
|
default 132
|
|
|
|
<tag/<tt/<it/length///
|
|
|
|
is the value from the <tt/pl/ (page length)
|
|
capability, default 66
|
|
|
|
<tag/<tt/<it/indent///
|
|
|
|
is the amount of the indentation from <tt/lpr -i/,
|
|
default 0
|
|
|
|
<tag/<tt/<it/login///
|
|
|
|
is the account name of the user printing the file
|
|
|
|
<tag/<tt/<it/host///
|
|
|
|
is the host name from which the job was submitted
|
|
|
|
<tag/<tt/<it/acct-file///
|
|
|
|
is the name of the accounting file from the <tt/af/
|
|
capability.
|
|
|
|
</descrip>
|
|
|
|
<item>A <em/conversion filter/ converts a specific file
|
|
format into one the printer can render onto paper.
|
|
For example, ditroff typesetting data cannot be
|
|
directly printed, but you can install a conversion
|
|
filter for ditroff files to convert the ditroff data
|
|
into a form the printer can digest and print. Section
|
|
<ref id="printing:advanced:convfilters"
|
|
name="Conversion Filters"> tells all about them.
|
|
Conversion filters also need to do accounting, if you
|
|
need printer accounting.
|
|
|
|
Conversion filters are started with the following
|
|
arguments:
|
|
<tscreen>
|
|
<tt>-x<it/pixel-width/ -y<it/pixel-height/ -n <it/login/ -h <it/host/ <it/acct-file/</tt>
|
|
</tscreen>
|
|
where <it/pixel-width/ is the value from the <tt/px/
|
|
capability (default 0) and <it/pixel-height/ is the
|
|
value from the <tt/py/ capability (default 0).
|
|
|
|
<item>The <em/output filter/ is used only if there is no
|
|
text filter, or if header pages are enabled. In my
|
|
experience, output filters are rarely used. Section
|
|
<ref id="printing:advanced:of" name="Output Filters">
|
|
describe them. There are only two arguments to an
|
|
output filter:
|
|
<tscreen>
|
|
<tt>-w<it/width/ -l<it/length/</tt>
|
|
</tscreen>
|
|
which are identical to the text filters <tt/-w/ and
|
|
<tt/-l/ arguments.
|
|
</itemize>
|
|
|
|
Filters should also <em/exit/ with the following exit
|
|
status:
|
|
<descrip>
|
|
<tag/exit 0/
|
|
|
|
If the filter printed the file successfully.
|
|
|
|
<tag/exit 1/
|
|
|
|
If the filter failed to print the file but wants LPD
|
|
to try to print the file again. LPD will restart a
|
|
filter if it exits with this status.
|
|
|
|
<tag/exit 2/
|
|
|
|
If the filter failed to print the file and does not
|
|
want LPD to try again. LPD will throw out the file.
|
|
</descrip>
|
|
|
|
The text filter that comes with the FreeBSD release,
|
|
<tt>/usr/libexec/lpr/lpf</tt>, takes advantage of the page
|
|
width and length arguments to determine when to send a
|
|
form feed and how to account for printer usage. It uses
|
|
the login, host, and accounting file arguments to make the
|
|
accounting entries.
|
|
|
|
If you are shopping for filters, see if they are
|
|
LPD-compatible. If they are, they must support the
|
|
argument lists described above. If you plan on writing
|
|
filters for general use, then have them support the same
|
|
argument lists and exit codes.
|
|
|
|
<sect2><heading>Accommodating Plain Text Jobs on PostScript Printers
|
|
<label id="printing:advanced:if-conversion"></heading>
|
|
|
|
<p> If you are the only user of your computer and PostScript
|
|
(or other language-based) printer, and you promise to
|
|
never send plain text to your printer and to never use
|
|
features of various programs that will want to send plain
|
|
text to your printer, then you do not need to worry about
|
|
this section at all.
|
|
|
|
But, if you would like to send both PostScript and plain
|
|
text jobs to the printer, then you are urged to augment
|
|
your printer setup. To do so, we have the text filter
|
|
detect if the arriving job is plain text or PostScript.
|
|
All PostScript jobs must start with <tt/%!/ (for
|
|
other printer languages, see your printer documentation).
|
|
If those are the first two characters in the job, we have
|
|
PostScript, and can pass the rest of the job directly. If
|
|
those are not the first two characters in the file, then
|
|
the filter will convert the text into PostScript and print
|
|
the result.
|
|
|
|
How do we do this?
|
|
|
|
If you have got a serial printer, a great way to do it is to
|
|
install <tt/lprps/. <tt/lprps/ is a PostScript printer
|
|
filter which performs two-way communication with the
|
|
printer. It updates the printer's status file with
|
|
verbose information from the printer, so users and
|
|
administrators can see exactly what the state of the
|
|
printer is (such as ``toner low'' or ``paper jam''). But
|
|
more importantly, it includes a program called <tt/psif/
|
|
which detects whether the incoming job is plain text and
|
|
calls <tt/textps/ (another program that comes with
|
|
<tt/lprps/) to convert it to PostScript. It then uses
|
|
<tt/lprps/ to send the job to the printer.
|
|
|
|
<tt/lprps/ is part of the FreeBSD ports collection
|
|
(see <ref id="ports" name="The Ports Collection">).
|
|
You can fetch, build and install it
|
|
yourself, of course. After installing <tt/lprps/, just
|
|
specify the pathname to the <tt/psif/ program that is part
|
|
of <tt/lprps/. If you installed <tt/lprps/ from the ports
|
|
collection, use the following in the serial PostScript
|
|
printer's entry in <tt>/etc/printcap</tt>:
|
|
<tscreen><verb>
|
|
:if=/usr/local/libexec/psif:
|
|
</verb></tscreen>
|
|
You should also specify the <tt/rw/ capability; that tells
|
|
LPD to open the printer in read-write mode.
|
|
|
|
If you have a parallel PostScript printer (and therefore
|
|
cannot use two-way communication with the printer, which
|
|
<tt/lprps/ needs), you can use the following shell script
|
|
as the text filter:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# psif - Print PostScript or plain text on a PostScript printer
|
|
# Script version; NOT the version that comes with lprps
|
|
# Installed in /usr/local/libexec/psif
|
|
#
|
|
|
|
read first_line
|
|
first_two_chars=`expr "$first_line" : '\(..\)'`
|
|
|
|
if [ "$first_two_chars" = "%!" ]; then
|
|
#
|
|
# PostScript job, print it.
|
|
#
|
|
echo $first_line && cat && printf "\004" && exit 0
|
|
exit 2
|
|
else
|
|
#
|
|
# Plain text, convert it, then print it.
|
|
#
|
|
( echo $first_line; cat ) | /usr/local/bin/textps && printf "\004" && exit 0
|
|
exit 2
|
|
fi
|
|
</code>
|
|
In the above script, <tt/textps/ is a program we installed
|
|
separately to convert plain text to PostScript. You can
|
|
use any text-to-PostScript program you wish. The FreeBSD
|
|
ports collection (see <ref id="ports" name="The Ports
|
|
Collection">) includes a full featured text-to-PostScript
|
|
program called <tt/a2ps/ that you might want to
|
|
investigate.
|
|
|
|
<sect2><heading>Simulating PostScript on Non-PostScript Printers
|
|
<label id="printing:advanced:ps"></heading>
|
|
|
|
<p> PostScript is the <it/de facto/ standard for high
|
|
quality typesetting and printing. PostScript is, however,
|
|
an <em/expensive/ standard. Thankfully, Alladin
|
|
Enterprises has a free PostScript work-alike called
|
|
<it/Ghostscript/ that runs with FreeBSD. Ghostscript can
|
|
read most PostScript files and can render their pages onto
|
|
a variety of devices, including many brands of
|
|
non-PostScript printers. By installing Ghostscript and
|
|
using a special text filter for your printer, you can make
|
|
your non-PostScript printer act like a real PostScript
|
|
printer.
|
|
|
|
Ghostscript should be in the FreeBSD ports collection, if
|
|
you would like to install it from there. You can fetch,
|
|
build, and install it quite easily yourself, as well.
|
|
|
|
To simulate PostScript, we have the text filter detect if
|
|
it is printing a PostScript file. If it is not, then the
|
|
filter will pass the file directly to the printer;
|
|
otherwise, it will use Ghostscript to first convert the
|
|
file into a format the printer will understand.
|
|
|
|
Here is an example: the following script is a text filter
|
|
for Hewlett Packard DeskJet 500 printers. For other
|
|
printers, substitute the <tt/-sDEVICE/ argument to the
|
|
<tt/gs/ (Ghostscript) command. (Type <tt/gs -h/ to get a
|
|
list of devices the current installation of Ghostscript
|
|
supports.)
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# ifhp - Print Ghostscript-simulated PostScript on a DesJet 500
|
|
# Installed in /usr/local/libexec/hpif
|
|
|
|
#
|
|
# Treat LF as CR+LF:
|
|
#
|
|
printf "\033&k2G" || exit 2
|
|
|
|
#
|
|
# Read first two characters of the file
|
|
#
|
|
read first_line
|
|
first_two_chars=`expr "$first_line" : '\(..\)'`
|
|
|
|
if [ "$first_two_chars" = "%!" ]; then
|
|
#
|
|
# It is PostScript; use Ghostscript to scan-convert and print it
|
|
#
|
|
/usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 -sOutputFile=- - \
|
|
&& exit 0
|
|
|
|
else
|
|
#
|
|
# Plain text or HP/PCL, so just print it directly; print a form
|
|
# at the end to eject the last page.
|
|
#
|
|
echo $first_line && cat && printf "\f" && exit 2
|
|
fi
|
|
|
|
exit 2
|
|
</code>
|
|
Finally, you need to notify LPD of the filter via the
|
|
<tt/if/ capability:
|
|
<tscreen><verb>
|
|
:if=/usr/local/libexec/hpif:
|
|
</verb></tscreen>
|
|
That is it. You can type <tt/lpr plain.text/ and <tt/lpr
|
|
whatever.ps/ and both should print successfully.
|
|
|
|
|
|
<sect2><heading>Conversion Filters<label
|
|
id="printing:advanced:convfilters"></heading>
|
|
|
|
<p> After completing the simple setup described in <ref
|
|
name="Simple Printer Setup" id="printing:simple">, the
|
|
first thing you will probably want to do is install
|
|
conversion filters for your favorite file formats
|
|
(besides plain ASCII text).
|
|
|
|
<sect3><heading>Why Install Conversion Filters?</heading>
|
|
|
|
<p> Conversion filters make printing various kinds of
|
|
files easy. As an example, suppose we do a lot of work
|
|
with the TeX typesetting system, and we have a
|
|
PostScript printer. Every time we generate a DVI file
|
|
from TeX, we cannot print it directly until we convert
|
|
the DVI file into PostScript. The command sequence
|
|
goes like this:
|
|
<tscreen><verb>
|
|
dvips seaweed-analysis.dvi
|
|
lpr seaweed-analysis.ps
|
|
</verb></tscreen>
|
|
By installing a conversion filter for DVI files, we can
|
|
skip the hand conversion step each time by having LPD do
|
|
it for us. Now, each time we get a DVI file, we are just
|
|
one step away from printing it:
|
|
<tscreen><verb>
|
|
lpr -d seaweed-analysis.dvi
|
|
</verb></tscreen>
|
|
We got LPD to do the DVI file conversion for us by
|
|
specifying the <tt/-d/ option. Section <ref
|
|
id="printing:lpr:options:format" name="Formatting and
|
|
Conversion Options"> lists the conversion options.
|
|
|
|
For each of the conversion options you want a printer to
|
|
support, install a <em/conversion filter/ and specify
|
|
its pathname in <tt>/etc/printcap</tt>. A conversion
|
|
filter is like the text filter for the simple printer
|
|
setup (see section <ref id="printing:textfilter"
|
|
name="Installing the Text Filter">) except that instead
|
|
of printing plain text, the filter converts the file
|
|
into a format the printer can understand.
|
|
|
|
<sect3><heading>Which Conversions Filters Should I Install?
|
|
</heading>
|
|
|
|
<p> You should install the conversion filters you expect
|
|
to use. If you print a lot of DVI data, then a DVI
|
|
conversion filter is in order. If you have got plenty of
|
|
troff to print out, then you probably want a troff
|
|
filter.
|
|
|
|
The following table summarizes the filters that LPD
|
|
works with, their capability entries for the
|
|
<tt>/etc/printcap</tt> file, and how to invoke them with
|
|
the <tt/lpr/ command:
|
|
<code>
|
|
/etc/printcap
|
|
File type Capability lpr option
|
|
------------ ------------- ----------
|
|
cifplot cf -c
|
|
DVI df -d
|
|
plot gf -g
|
|
ditroff nf -n
|
|
FORTRAN text rf -f
|
|
troff tf -t
|
|
raster vf -v
|
|
plain text if none, -p, or -l
|
|
</code>
|
|
|
|
In our example, using <tt/lpr -d/ means the printer
|
|
needs a <tt/df/ capability in its entry in
|
|
<tt>/etc/printcap</tt>.
|
|
|
|
Despite what others might contend, formats like FORTRAN
|
|
text and plot are probably obsolete. At your site, you
|
|
can give new meanings to these or any of the formatting
|
|
options just by installing custom filters. For example,
|
|
suppose you would like to directly print Printerleaf files
|
|
(files from the Interleaf desktop publishing program),
|
|
but will never print plot files. You could install a
|
|
Printerleaf conversion filter under the <tt/gf/
|
|
capability and then educate your users that <tt/lpr -g/
|
|
mean ``print Printerleaf files.''
|
|
|
|
<sect3><heading>Installing Conversion Filters</heading>
|
|
|
|
<p> Since conversion filters are programs you install
|
|
outside of the base FreeBSD installation, they should
|
|
probably go under <tt>/usr/local</tt>. The directory
|
|
<tt>/usr/local/libexec</tt> is a popular location, since
|
|
they are specialized programs that only LPD will
|
|
run; regular users should not ever need to run them.
|
|
|
|
To enable a conversion filter, specify its pathname
|
|
under the appropriate capability for the destination
|
|
printer in <tt>/etc/printcap</tt>.
|
|
|
|
In our example, we will add the DVI conversion filter to
|
|
the entry for the printer named <tt/bamboo/. Here is the
|
|
example <tt>/etc/printcap</tt> file again, with the new
|
|
<tt/df/ capability for the printer <tt/bamboo/
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose - added df filter for bamboo
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:\
|
|
:lp=/dev/lpt0:\
|
|
:if=/usr/local/libexec/if-simple:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:\
|
|
:lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\
|
|
:if=/usr/local/libexec/psif:\
|
|
:df=/usr/local/libexec/psdf:
|
|
</code>
|
|
The DVI filter is a shell script named
|
|
<tt>/usr/local/libexec/psdf</tt>. Here is that script:
|
|
<code>
|
|
#!bin/sh
|
|
#
|
|
# psdf - DVI to PostScript printer filter
|
|
# Installed in /usr/local/libexec/psdf
|
|
#
|
|
# Invoked by lpd when user runs lpr -d
|
|
#
|
|
exec /usr/local/bin/dvips -f | /usr/local/libexec/lprps "$@"
|
|
</code>
|
|
This script runs <tt/dvips/ in filter mode (the <tt/-f/
|
|
argument) on standard input, which is the job to print.
|
|
It then starts the PostScript printer filter <tt/lprps/
|
|
(see section <ref id="printing:advanced:if-conversion"
|
|
name="Accommodating Plain Text Jobs on PostScript
|
|
Printers">) with the arguments LPD passed to this script.
|
|
<tt/lprps/ will use those arguments to account for the
|
|
pages printed.
|
|
|
|
<sect3><heading>More Conversion Filter Examples</heading>
|
|
|
|
<p> Since there is no fixed set of steps to install
|
|
conversion filters, let me instead provide more
|
|
examples. Use these as guidance to making your own
|
|
filters. Use them directly, if appropriate.
|
|
|
|
This example script is a raster (well, GIF file,
|
|
actually) conversion filter for a Hewlett Packard
|
|
LaserJet III-Si printer:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# hpvf - Convert GIF files into HP/PCL, then print
|
|
# Installed in /usr/local/libexec/hpvf
|
|
|
|
PATH=/usr/X11R6/bin:$PATH; export PATH
|
|
|
|
giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \
|
|
&& exit 0 \
|
|
|| exit 2
|
|
</code>
|
|
It works by converting the GIF file into a portable
|
|
anymap, converting that into a portable graymap,
|
|
converting that into a portable bitmap, and converting
|
|
that into LaserJet/PCL-compatible data.
|
|
|
|
Here is the <tt>/etc/printcap</tt> file with an entry for
|
|
a printer using the above filter:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host orchid
|
|
#
|
|
teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\
|
|
:lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\
|
|
:if=/usr/local/libexec/hpif:\
|
|
:vf=/usr/local/libexec/hpvf:
|
|
</code>
|
|
|
|
The following script is a conversion filter for troff
|
|
data from the groff typesetting system for the
|
|
PostScript printer named <tt/bamboo/:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# pstf - Convert groff's troff data into PS, then print.
|
|
# Installed in /usr/local/libexec/pstf
|
|
#
|
|
exec grops | /usr/local/libexec/lprps "$@"
|
|
</code>
|
|
The above script makes use of <tt/lprps/ again to handle
|
|
the communication with the printer. If the printer were
|
|
on a parallel port, we would use this script instead:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# pstf - Convert groff's troff data into PS, then print.
|
|
# Installed in /usr/local/libexec/pstf
|
|
#
|
|
exec grops
|
|
</code>
|
|
That is it. Here is the entry we need to add to
|
|
<tt>/etc/printcap</tt> to enable the filter:
|
|
<tscreen><verb>
|
|
:tf=/usr/local/libexec/pstf:
|
|
</verb></tscreen>
|
|
|
|
Here is an example that might make old hands at FORTRAN
|
|
blush. It is a FORTRAN-text filter for any printer that
|
|
can directly print plain text. We will install it for the
|
|
printer <tt/teak/:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# hprf - FORTRAN text filter for LaserJet 3si:
|
|
# Installed in /usr/local/libexec/hprf
|
|
#
|
|
|
|
printf "\033&k2G" && fpr && printf "\f" && exit 0
|
|
exit 2
|
|
</code>
|
|
And we will add this line to the <tt>/etc/printcap</tt>
|
|
for the printer <tt/teak/ to enable this filter:
|
|
<tscreen><verb>
|
|
:rf=/usr/local/libexec/hprf:
|
|
</verb></tscreen>
|
|
|
|
Here is one final, somewhat complex example. We will add a
|
|
DVI filter to the LaserJet printer <tt/teak/ introduced
|
|
earlier. First, the easy part: updating
|
|
<tt>/etc/printcap</tt> with the location of the DVI
|
|
filter:
|
|
<tscreen><verb>
|
|
:df=/usr/local/libexec/hpdf:
|
|
</verb></tscreen>
|
|
|
|
Now, for the hard part: making the filter. For that, we
|
|
need a DVI-to-LaserJet/PCL conversion program. The
|
|
FreeBSD ports collection (see <ref id="ports" name="The
|
|
Ports Collection">) has one: <tt/dvi2xx/ is the name of
|
|
the package. Installing this package gives us the
|
|
program we need, <tt/dvilj2p/, which converts DVI into
|
|
LaserJet IIp, LaserJet III, and LaserJet 2000 compatible
|
|
codes.
|
|
|
|
<tt/dvilj2p/ makes the filter <tt/hpdf/ quite complex
|
|
since <tt/dvilj2p/ cannot read from standard input. It
|
|
wants to work with a filename. What is worse, the
|
|
filename has to end in <tt/.dvi/ so using
|
|
<tt>/dev/fd/0</tt> for standard input is problematic.
|
|
We can get around that problem by linking (symbolically)
|
|
a temporary file name (one that ends in <tt/.dvi/) to
|
|
<tt>/dev/fd/0</tt>, thereby forcing <tt/dvilj2p/ to read
|
|
from standard input.
|
|
|
|
The only other fly in the ointment is the fact that we
|
|
cannot use /tmp for the temporary link. Symbolic links
|
|
are owned by user and group <tt/bin/. The filter runs
|
|
as user <tt/daemon/. And the <tt>/tmp</tt> directory
|
|
has the sticky bit set. The filter can create the link,
|
|
but it will not be able clean up when done and remove it
|
|
since the link will belong to a different user.
|
|
|
|
Instead, the filter will make the symbolic link in the
|
|
current working directory, which is the spooling
|
|
directory (specified by the <tt/sd/ capability in
|
|
<tt>/etc/printcap</tt>). This is a perfect place for
|
|
filters to do their work, especially since there is
|
|
(sometimes) more free disk space in the spooling directory
|
|
than under <tt>/tmp</tt>.
|
|
|
|
Here, finally, is the filter:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# hpdf - Print DVI data on HP/PCL printer
|
|
# Installed in /usr/local/libexec/hpdf
|
|
|
|
PATH=/usr/local/bin:$PATH; export PATH
|
|
|
|
#
|
|
# Define a function to clean up our temporary files. These exist
|
|
# in the current directory, which will be the spooling directory
|
|
# for the printer.
|
|
#
|
|
cleanup() {
|
|
rm -f hpdf$$.dvi
|
|
}
|
|
|
|
#
|
|
# Define a function to handle fatal errors: print the given message
|
|
# and exit 2. Exiting with 2 tells LPD to do not try to reprint the
|
|
# job.
|
|
#
|
|
fatal() {
|
|
echo "$@" 1>&2
|
|
cleanup
|
|
exit 2
|
|
}
|
|
|
|
#
|
|
# If user removes the job, LPD will send SIGINT, so trap SIGINT
|
|
# (and a few other signals) to clean up after ourselves.
|
|
#
|
|
trap cleanup 1 2 15
|
|
|
|
#
|
|
# Make sure we are not colliding with any existing files.
|
|
#
|
|
cleanup
|
|
|
|
#
|
|
# Link the DVI input file to standard input (the file to print).
|
|
#
|
|
ln -s /dev/fd/0 hpdf$$.dvi || fatal "Cannot symlink /dev/fd/0"
|
|
|
|
#
|
|
# Make LF = CR+LF
|
|
#
|
|
printf "\033&k2G" || fatal "Cannot initialize printer"
|
|
|
|
#
|
|
# Convert and print. Return value from dvilj2p does not seem to be
|
|
# reliable, so we ignore it.
|
|
#
|
|
dvilj2p -M1 -q -e- dfhp$$.dvi
|
|
|
|
#
|
|
# Clean up and exit
|
|
#
|
|
cleanup
|
|
exit 0
|
|
</code>
|
|
|
|
<sect3><heading>Automated Conversion: An Alternative To Conversion Filters
|
|
<label id="printing:advanced:autoconv"></heading>
|
|
|
|
<p> All these conversion filters accomplish a lot for your
|
|
printing environment, but at the cost forcing the user
|
|
to specify (on the <tt/lpr/ command line) which one to
|
|
use. If your users are not particularly computer
|
|
literate, having to specify a filter option will become
|
|
annoying. What is worse, though, is that an incorrectly
|
|
specified filter option may run a filter on the wrong
|
|
type of file and cause your printer to spew out hundreds
|
|
of sheets of paper.
|
|
|
|
Rather than install conversion filters at all, you might
|
|
want to try having the text filter (since it is the
|
|
default filter) detect the type of file it has been asked to
|
|
print and then automatically run the right conversion
|
|
filter. Tools such as <tt/file/ can be of help here.
|
|
Of course, it will be hard to determine the differences
|
|
between <em/some/ file types---and, of course, you can
|
|
still provide conversion filters just for them.
|
|
|
|
The FreeBSD ports collection has a text filter that
|
|
performs automatic conversion called <tt/apsfilter/. It
|
|
can detect plain text, PostScript, and DVI files, run
|
|
the proper conversions, and print.
|
|
|
|
<sect2><heading>Output Filters<label
|
|
id="printing:advanced:of"></heading>
|
|
|
|
<p> The LPD spooling system supports one other type of
|
|
filter that we have not yet explored: an output filter. An
|
|
output filter is intended for printing plain text only,
|
|
like the text filter, but with many simplifications. If
|
|
you are using an output filter but no text filter, then
|
|
<itemize>
|
|
<item>LPD starts an output filter once for the entire
|
|
job instead of once for each file in the job.
|
|
|
|
<item>LPD does not make any provision to identify the
|
|
start or the end of files within the job for the
|
|
output filter.
|
|
|
|
<item>LPD does not pass the user's login or host to
|
|
the filter, so it is not intended to do accounting. In
|
|
fact, it gets only two arguments:
|
|
<tscreen>
|
|
<tt>-w<it/width/ -l<it/length/</tt>
|
|
</tscreen>
|
|
where <it/width/ is from the <tt/pw/ capability and
|
|
<it/length/ is from the <tt/pl/ capability for the
|
|
printer in question.
|
|
</itemize>
|
|
|
|
Do not be seduced by an output filter's simplicity. If
|
|
you would like each file in a job to start on a different page
|
|
an output filter <em/will not work/. Use a text filter (also
|
|
known as an input filter); see section <ref
|
|
id="printing:textfilter" name="Installing the Text
|
|
Filter">. Furthermore, an output filter is actually
|
|
<em/more complex/ in that it has to examine the byte
|
|
stream being sent to it for special flag characters and
|
|
must send signals to itself on behalf of LPD.
|
|
|
|
However, an output filter is <em/necessary/ if you want
|
|
header pages and need to send escape sequences or other
|
|
initialization strings to be able to print the header
|
|
page. (But it is also <em/futile/ if you want to charge
|
|
header pages to the requesting user's account, since LPD
|
|
does not give any user or host information to the output
|
|
filter.)
|
|
|
|
On a single printer, LPD allows both an output filter and
|
|
text or other filters. In such cases, LPD will start the
|
|
output filter to print the header page (see section <ref
|
|
id="printing:advanced:header-pages" name="Header Pages">)
|
|
only. LPD then expects the output filter to <em/stop
|
|
itself/ by sending two bytes to the filter: ASCII 031
|
|
followed by ASCII 001. When an output filter sees these
|
|
two bytes (031, 001), it should stop by sending SIGSTOP to
|
|
itself. When LPD's done running other filters, it will
|
|
restart the output filter by sending SIGCONT to it.
|
|
|
|
If there is an output filter but <em/no/ text filter and
|
|
LPD is working on a plain text job, LPD uses the output
|
|
filter to do the job. As stated before, the output filter
|
|
will print each file of the job in sequence with no
|
|
intervening form feeds or other paper advancement, and
|
|
this is probably <em/not/ what you want. In almost all
|
|
cases, you need a text filter.
|
|
|
|
The program <tt/lpf/, which we introduced earlier as a text
|
|
filter, can also run as an output filter. If you need a
|
|
quick-and-dirty output filter but do not want to write the
|
|
byte detection and signal sending code, try <tt/lpf/. You
|
|
can also wrap <tt/lpf/ in a shell script to handle any
|
|
initialization codes the printer might require.
|
|
|
|
<sect2><heading><tt/lpf/: a Text Filter<label
|
|
id="printing:advanced:lpf"></heading>
|
|
|
|
<p> The program <tt>/usr/libexec/lpr/lpf</tt> that comes
|
|
with FreeBSD binary distribution is a text filter (input
|
|
filter) that can indent output (job submitted with <tt/lpr
|
|
-i/), allow literal characters to pass (job submitted with
|
|
<tt/lpr -l/), adjust the printing position for backspaces
|
|
and tabs in the job, and account for pages printed. It
|
|
can also act like an output filter.
|
|
|
|
<tt/lpf/ is suitable for many printing environments. And
|
|
although it has no capability to send initialization
|
|
sequences to a printer, it is easy to write a shell script
|
|
to do the needed initialization and then execute <tt/lpf/.
|
|
|
|
In order for <tt/lpf/ to do page accounting correctly, it
|
|
needs correct values filled in for the <tt/pw/ and <tt/pl/
|
|
capabilities in the <tt>/etc/printcap</tt> file. It uses
|
|
these values to determine how much text can fit on a page
|
|
and how many pages were in a user's job. For more
|
|
information on printer accounting, see <ref
|
|
id="printing:advanced:acct" name="Accounting for Printer
|
|
Usage">.
|
|
|
|
<sect1><heading>Header Pages<label
|
|
id="printing:advanced:header-pages"></heading>
|
|
|
|
<p> If you have <em/lots/ of users, all of them using
|
|
various printers, then you probably want to consider
|
|
<em/header pages/ as a necessary evil.
|
|
|
|
Header pages, also known as <em/banner/ or <em/burst pages/
|
|
identify to whom jobs belong after they are printed. They are
|
|
usually printed in large, bold letters, perhaps with
|
|
decorative borders, so that in a stack of printouts they
|
|
stand out from the real documents that comprise users' jobs.
|
|
They enable users to locate their jobs quickly. The obvious
|
|
drawback to a header page is that it is yet one more sheet
|
|
that has to be printed for every job, their ephemeral
|
|
usefulness lasting not more than a few minutes, ultimately
|
|
finding themselves in a recycling bin or rubbish heap.
|
|
(Note that header pages go with each job, not each file in a
|
|
job, so the paper waste might not be that bad.)
|
|
|
|
The LPD system can provide header pages automatically for
|
|
your printouts <em/if/ your printer can directly print plain
|
|
text. If you have a PostScript printer, you will need an
|
|
external program to generate the header page; see <ref
|
|
id="printing:advanced:header-pages:ps" name="Header Pages on
|
|
PostScript Printers">.
|
|
|
|
<sect2><heading>Enabling Header Pages<label
|
|
id="printing:advanced:header-pages:enabling"></heading>
|
|
|
|
<p> In the <ref id="printing:simple" name="Simple Printer
|
|
Setup">, we turned off header pages by specifying
|
|
<tt/sh/ (meaning ``suppress header'') in the
|
|
<tt>/etc/printcap</tt> file. To enable header pages for
|
|
a printer, just remove the <tt/sh/ capability.
|
|
|
|
Sounds too easy, right?
|
|
|
|
You are right. You <em/might/ have to provide an output
|
|
filter to send initialization strings to the printer.
|
|
Here is an example output filter for Hewlett Packard
|
|
PCL-compatible printers:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# hpof - Output filter for Hewlett Packard PCL-compatible printers
|
|
# Installed in /usr/local/libexec/hpof
|
|
|
|
|
|
printf "\033&k2G" || exit 2
|
|
exec /usr/libexec/lpr/lpf
|
|
</code>
|
|
Specify the path to the output filter in the <tt/of/
|
|
capability. See <ref id="printing:advanced:of"
|
|
name="Output Filters"> for more information.
|
|
|
|
Here is an example <tt>/etc/printcap</tt> file for the printer
|
|
<tt/teak/ that we introduced earlier; we enabled header
|
|
pages and added the above output filter:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host orchid
|
|
#
|
|
teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\
|
|
:lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\
|
|
:if=/usr/local/libexec/hpif:\
|
|
:vf=/usr/local/libexec/hpvf:\
|
|
:of=/usr/local/libexec/hpof:
|
|
</code>
|
|
Now, when users print jobs to <tt/teak/, they get a header
|
|
page with each job. If users want to spend time searching
|
|
for their printouts, they can suppress header pages by
|
|
submitting the job with <tt/lpr -h/; see <ref
|
|
id="printing:lpr:options:misc" name="Header Page Options">
|
|
for more <tt/lpr/ options.
|
|
|
|
<tt/Note:/ LPD prints a form feed character after the
|
|
header page. If your printer uses a different character
|
|
or sequence of characters to eject a page, specify them
|
|
with the <tt/ff/ capability in <tt>/etc/printcap</tt>.
|
|
|
|
<sect2><heading>Controlling Header Pages<label
|
|
id="printing:advanced:header-pages:controlling"></heading>
|
|
|
|
<p> By enabling header pages, LPD will produce a <em/long
|
|
header/, a full page of large letters identifying the
|
|
user, host, and job. Here is an example (kelly printed
|
|
the job named outline from host rose):
|
|
<tscreen><verb>
|
|
k ll ll
|
|
k l l
|
|
k l l
|
|
k k eeee l l y y
|
|
k k e e l l y y
|
|
k k eeeeee l l y y
|
|
kk k e l l y y
|
|
k k e e l l y yy
|
|
k k eeee lll lll yyy y
|
|
y
|
|
y y
|
|
yyyy
|
|
|
|
|
|
ll
|
|
t l i
|
|
t l
|
|
oooo u u ttttt l ii n nnn eeee
|
|
o o u u t l i nn n e e
|
|
o o u u t l i n n eeeeee
|
|
o o u u t l i n n e
|
|
o o u uu t t l i n n e e
|
|
oooo uuu u tt lll iii n n eeee
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
r rrr oooo ssss eeee
|
|
rr r o o s s e e
|
|
r o o ss eeeeee
|
|
r o o ss e
|
|
r o o s s e e
|
|
r oooo ssss eeee
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Job: outline
|
|
Date: Sun Sep 17 11:04:58 1995
|
|
</verb></tscreen>
|
|
LPD appends a form feed after this text so the job starts
|
|
on a new page (unless you have <tt/sf/ (suppress form
|
|
feeds) in the destination printer's entry in
|
|
<tt>/etc/printcap</tt>).
|
|
|
|
If you prefer, LPD can make a <em/short header/; specify
|
|
<tt/sb/ (short banner) in the <tt>/etc/printcap</tt> file.
|
|
The header page will look like this:
|
|
<tscreen><verb>
|
|
rose:kelly Job: outline Date: Sun Sep 17 11:07:51 1995
|
|
</verb></tscreen>
|
|
Also by default, LPD prints the header page first, then
|
|
the job. To reverse that, specify <tt/hl/ (header last)
|
|
in <tt>/etc/printcap</tt>.
|
|
|
|
<sect2><heading>Accounting for Header Pages<label
|
|
id="printing:advanced:header-pages:accounting"></heading>
|
|
|
|
<p> Using LPD's built-in header pages enforces a particular
|
|
paradigm when it comes to printer accounting: header pages
|
|
must be <em/free of charge/.
|
|
|
|
Why?
|
|
|
|
Because the output filter is the only external program
|
|
that will have control when the header page is printed
|
|
that could do accounting, and it is not provided with any
|
|
<em/user or host/ information or an accounting file, so it
|
|
has no idea whom to charge for printer use. It is also not
|
|
enough to just ``add one page'' to the text filter or any
|
|
of the conversion filters (which do have user and host
|
|
information) since users can suppress header pages with
|
|
<tt/lpr -h/. They could still be charged for header pages
|
|
they did not print. Basically, <tt/lpr -h/ will be the
|
|
preferred option of environmentally-minded users, but you
|
|
cannot offer any incentive to use it.
|
|
|
|
It is <em/still not enough/ to have each of the filters
|
|
generate their own header pages (thereby being able to
|
|
charge for them). If users wanted the option of
|
|
suppressing the header pages with <tt/lpr -h/, they will
|
|
still get them and be charged for them since LPD does not
|
|
pass any knowledge of the <tt/-h/ option to any of the
|
|
filters.
|
|
|
|
So, what are your options?
|
|
|
|
You can
|
|
<itemize>
|
|
<item>Accept LPD's paradigm and make header pages free.
|
|
|
|
<item>Install an alternative to LPD, such as LPDng or
|
|
PLP. Section <ref name="Alternatives to the Standard
|
|
Spooler" id="printing:lpd-alternatives"> tells more
|
|
about other spooling software you can substitute for
|
|
LPD.
|
|
|
|
<item>Write a <em/smart/ output filter. Normally, an
|
|
output filter is not meant to do anything more than
|
|
initialize a printer or do some simple character
|
|
conversion. It is suited for header pages and plain
|
|
text jobs (when there is no text (input) filter).
|
|
|
|
But, if there is a text filter for the plain text
|
|
jobs, then LPD will start the output filter only for
|
|
the header pages. And the output filter can parse the
|
|
header page text that LPD generates to determine what
|
|
user and host to charge for the header page. The only
|
|
other problem with this method is that the output
|
|
filter still does not know what accounting file to use
|
|
(it is not passed the name of the file from the <tt/af/
|
|
capability), but if you have a well-known accounting
|
|
file, you can hard-code that into the output filter.
|
|
|
|
To facilitate the parsing step, use the <tt/sh/ (short
|
|
header) capability in <tt>/etc/printcap</tt>.
|
|
|
|
Then again, all that might be too much trouble, and
|
|
users will certainly appreciate the more generous
|
|
system administrator who makes header pages free.
|
|
</itemize>
|
|
|
|
<sect2><heading>Header Pages on PostScript Printers<label
|
|
id="printing:advanced:header-pages:ps"></heading>
|
|
|
|
<p> As described above, LPD can generate a plain text header
|
|
page suitable for many printers. Of course, PostScript
|
|
cannot directly print plain text, so the header page
|
|
feature of LPD is useless---or mostly so.
|
|
|
|
One obvious way to get header pages is to have every
|
|
conversion filter and the text filter generate the header
|
|
page. The filters should should use the user and host
|
|
arguments to generate a suitable header page. The
|
|
drawback of this method is that users will always get a
|
|
header page, even if they submit jobs with <tt/lpr -h/.
|
|
|
|
Let us explore this method. The following script takes
|
|
three arguments (user login name, host name, and job name)
|
|
and makes a simple PostScript header page:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# make-ps-header - make a PostScript header page on stdout
|
|
# Installed in /usr/local/libexec/make-ps-header
|
|
#
|
|
|
|
#
|
|
# These are PostScript units (72 to the inch). Modify for A4 or
|
|
# whatever size paper you are using:
|
|
#
|
|
page_width=612
|
|
page_height=792
|
|
border=72
|
|
|
|
#
|
|
# Check arguments
|
|
#
|
|
if [ $# -ne 3 ]; then
|
|
echo "Usage: `basename $0` <user> <host> <job>" 1>&2
|
|
exit 1
|
|
fi
|
|
|
|
#
|
|
# Save these, mostly for readability in the PostScript, below.
|
|
#
|
|
user=$1
|
|
host=$2
|
|
job=$3
|
|
date=`date`
|
|
|
|
#
|
|
# Send the PostScript code to stdout.
|
|
#
|
|
exec cat <<EOF
|
|
%!PS
|
|
|
|
%
|
|
% Make sure we do not interfere with user's job that will follow
|
|
%
|
|
save
|
|
|
|
%
|
|
% Make a thick, unpleasant border around the edge of the paper.
|
|
%
|
|
$border $border moveto
|
|
$page_width $border 2 mul sub 0 rlineto
|
|
0 $page_height $border 2 mul sub rlineto
|
|
currentscreen 3 -1 roll pop 100 3 1 roll setscreen
|
|
$border 2 mul $page_width sub 0 rlineto closepath
|
|
0.8 setgray 10 setlinewidth stroke 0 setgray
|
|
|
|
%
|
|
% Display user's login name, nice and large and prominent
|
|
%
|
|
/Helvetica-Bold findfont 64 scalefont setfont
|
|
$page_width ($user) stringwidth pop sub 2 div $page_height 200 sub moveto
|
|
($user) show
|
|
|
|
%
|
|
% Now show the boring particulars
|
|
%
|
|
/Helvetica findfont 14 scalefont setfont
|
|
/y 200 def
|
|
[ (Job:) (Host:) (Date:) ] {
|
|
200 y moveto show /y y 18 sub def
|
|
} forall
|
|
|
|
/Helvetica-Bold findfont 14 scalefont setfont
|
|
/y 200 def
|
|
[ ($job) ($host) ($date) ] {
|
|
270 y moveto show /y y 18 sub def
|
|
} forall
|
|
|
|
%
|
|
% That is it
|
|
%
|
|
restore
|
|
showpage
|
|
EOF
|
|
</code>
|
|
Now, each of the conversion filters and the text filter
|
|
can call this script to first generate the header page,
|
|
and then print the user's job. Here is the DVI conversion
|
|
filter from earlier in this document, modified to make a
|
|
header page:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# psdf - DVI to PostScript printer filter
|
|
# Installed in /usr/local/libexec/psdf
|
|
#
|
|
# Invoked by lpd when user runs lpr -d
|
|
#
|
|
|
|
orig_args="$@"
|
|
|
|
fail() {
|
|
echo "$@" 1>&2
|
|
exit 2
|
|
}
|
|
|
|
while getopts "x:y:n:h:" option; do
|
|
case $option in
|
|
x|y) ;; # Ignore
|
|
n) login=$OPTARG ;;
|
|
h) host=$OPTARG ;;
|
|
*) echo "LPD started `basename $0` wrong." 1>&2
|
|
exit 2
|
|
;;
|
|
esac
|
|
done
|
|
|
|
[ "$login" ] || fail "No login name"
|
|
[ "$host" ] || fail "No host name"
|
|
|
|
( /usr/local/libexec/make-ps-header $login $host "DVI File"
|
|
/usr/local/bin/dvips -f ) | eval /usr/local/libexec/lprps $orig_args
|
|
</code>
|
|
Notice how the filter has to parse the argument list in
|
|
order to determine the user and host name. The parsing
|
|
for the other conversion filters is identical. The text
|
|
filter takes a slightly different set of arguments, though
|
|
(see section <ref id="printing:advanced:filters" name="How
|
|
Filters Work">).
|
|
|
|
As we have mentioned before, the above scheme, though fairly
|
|
simple, disables the ``suppress header page'' option (the
|
|
<tt/-h/ option) to <tt/lpr/. If users wanted to save a
|
|
tree (or a few pennies, if you charge for header pages),
|
|
they would not be able to do so, since every filter's going
|
|
to print a header page with every job.
|
|
|
|
To allow users to shut off header pages on a per-job
|
|
basis, you will need to use the trick introduced in section
|
|
<ref id="printing:advanced:header-pages:accounting"
|
|
name="Accounting for Header Pages">: write an output
|
|
filter that parses the LPD-generated header page and
|
|
produces a PostScript version. If the user submits the
|
|
job with <tt/lpr -h/, then LPD will not generate a header
|
|
page, and neither will your output filter. Otherwise,
|
|
your output filter will read the text from LPD and send
|
|
the appropriate header page PostScript code to the
|
|
printer.
|
|
|
|
If you have a PostScript printer on a serial line, you
|
|
can make use of <tt/lprps/, which comes with an output
|
|
filter, <tt/psof/, which does the above. Note that
|
|
<tt/psof/ does not charge for header pages.
|
|
|
|
<sect1><heading>Networked Printing<label
|
|
id="printing:advanced:network-printers"></heading>
|
|
|
|
<p> FreeBSD supports networked printing: sending jobs to
|
|
remote printers. Networked printing generally refers to two
|
|
different things:
|
|
<itemize>
|
|
<item>Accessing a printer attached to a remote host. You
|
|
install a printer that has a conventional serial or
|
|
parallel interface on one host. Then, you set up LPD to
|
|
enable access to the printer from other hosts on the
|
|
network. Section <ref id="printing:advanced:network:rm"
|
|
name="Printers Installed on Remote Hosts"> tells how to
|
|
do this.
|
|
|
|
<item>Accessing a printer attached directly to a network.
|
|
The printer has a network interface in addition (or in
|
|
place of) a more conventional serial or parallel
|
|
interface. Such a printer might work as follows:
|
|
|
|
<itemize>
|
|
<item>It might understand the LPD protocol and can
|
|
even queue jobs from remote hosts. In this case, it
|
|
acts just like a regular host running LPD. Follow
|
|
the same procedure in section <ref
|
|
id="printing:advanced:network:rm" name="Printers
|
|
Installed on Remote Hosts"> to set up such a
|
|
printer.
|
|
|
|
<item>It might support a data stream network
|
|
connection. In this case, you ``attach'' the
|
|
printer to one host on the network by making that
|
|
host responsible for spooling jobs and sending them
|
|
to the printer. Section <ref
|
|
id="printing:advanced:network:net-if" name="Printers
|
|
with Networked Data Stream Interfaces"> gives some
|
|
suggestions on installing such printers.
|
|
</itemize>
|
|
</itemize>
|
|
|
|
<sect2><heading>Printers Installed on Remote Hosts<label
|
|
id="printing:advanced:network:rm"></heading>
|
|
|
|
<p> The LPD spooling system has built-in support for sending
|
|
jobs to other hosts also running LPD (or are compatible
|
|
with LPD). This feature enables you to install a printer
|
|
on one host and make it accessible from other hosts. It
|
|
also works with printers that have network interfaces that
|
|
understand the LPD protocol.
|
|
|
|
To enable this kind of remote printing, first install a
|
|
printer on one host, the <em/printer host/, using the
|
|
simple printer setup described in <ref
|
|
id="printing:simple" name="Simple Printer Setup">. Do any
|
|
advanced setup in <ref id="printing:advanced"
|
|
name="Advanced Printer Setup"> that you need. Make sure
|
|
to test the printer and see if it works with the features
|
|
of LPD you have enabled.
|
|
|
|
If you are using a printer with a network interface that is
|
|
compatible with LPD, then the <em/printer host/ in the
|
|
discussion below is the printer itself, and the
|
|
<em/printer name/ is the name you configured for the
|
|
printer. See the documentation that accompanied your
|
|
printer and/or printer-network interface.
|
|
|
|
Then, on the other hosts you want to have access to the
|
|
printer, make an entry in their <tt>/etc/printcap</tt>
|
|
files with the following:
|
|
<enum>
|
|
<item>Name the entry anything you want. For
|
|
simplicity, though, you probably want to use the same
|
|
name and aliases as on the printer host.
|
|
|
|
<item>Leave the <tt/lp/ capability blank, explicitly
|
|
(<tt/:lp=:/).
|
|
|
|
<item>Make a spooling directory and specify its
|
|
location in the <tt/sd/ capability. LPD will store
|
|
jobs here before they get sent to the printer host.
|
|
|
|
<item>Place the name of the printer host in the <tt/rm/
|
|
capability.
|
|
|
|
<item>Place the printer name on the <em/printer host/ in
|
|
the <tt/rp/ capability.
|
|
</enum>
|
|
That is it. You do not need to list conversion filters,
|
|
page dimensions, or anything else in the
|
|
<tt>/etc/printcap</tt> file.
|
|
|
|
Here is an example. The host rose has two printers,
|
|
<tt/bamboo/ and <tt/rattan/. We will enable users on the
|
|
host orchid to print to those printers. Here is the
|
|
<tt>/etc/printcap</tt> file for orchid (back from section
|
|
<ref id="printing:advanced:header-pages:enabling"
|
|
name="Enabling Header Pages">). It already had the entry
|
|
for the printer <tt/teak/; we have added entries for the two
|
|
printers on the host rose:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host orchid - added (remote) printers on rose
|
|
#
|
|
|
|
#
|
|
# teak is local; it is connected directly to orchid:
|
|
#
|
|
teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\
|
|
:lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\
|
|
:if=/usr/local/libexec/ifhp:\
|
|
:vf=/usr/local/libexec/vfhp:\
|
|
:of=/usr/local/libexec/ofhp:
|
|
|
|
#
|
|
# rattan is connected to rose; send jobs for rattan to rose:
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan:
|
|
|
|
#
|
|
# bamboo is connected to rose as well:
|
|
#
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:
|
|
</code>
|
|
Then, we just need to make spooling directories on orchid:
|
|
<tscreen><verb>
|
|
mkdir -p /var/spool/lpd/rattan /var/spool/lpd/bamboo
|
|
chmod 770 /var/spool/lpd/rattan /var/spool/lpd/bamboo
|
|
chown daemon.daemon /var/spool/lpd/rattan /var/spool/lpd/bamboo
|
|
</verb></tscreen>
|
|
|
|
Now, users on orchid can print to <tt/rattan/ and
|
|
<tt/bamboo/. If, for example, a user on orchid typed
|
|
<tscreen><verb>
|
|
lpr -P bamboo -d sushi-review.dvi
|
|
</verb></tscreen>
|
|
the LPD system on orchid would copy the job to the
|
|
spooling directory <tt>/var/spool/lpd/bamboo</tt> and note
|
|
that it was a DVI job. As soon as the host rose has room
|
|
in its <tt/bamboo/ spooling directory, the two
|
|
LPDs would transfer the file to rose. The file would wait
|
|
in rose's queue until it was finally printed. It would be
|
|
converted from DVI to PostScript (since bamboo is a
|
|
PostScript printer) on rose.
|
|
|
|
<sect2><heading>Printers with Networked Data Stream Interfaces<label
|
|
id="printing:advanced:network:net-if"></heading>
|
|
|
|
<p> Often, when you buy a network interface card for a
|
|
printer, you can get two versions: one which emulates a
|
|
spooler (the more expensive version), or one which just
|
|
lets you send data to it as if you were using a serial or
|
|
parallel port (the cheaper version). This section tells
|
|
how to use the cheaper version. For the more expensive
|
|
one, see the previous section <ref name="Printers
|
|
Installed on Remote Hosts" id="printing:advanced:network:rm">.
|
|
|
|
The format of the <tt>/etc/printcap</tt> file lets you
|
|
specify what serial or parallel interface to use, and (if
|
|
you are using a serial interface), what baud rate, whether
|
|
to use flow control, delays for tabs, conversion of
|
|
newlines, and more. But there is no way to specify a
|
|
connection to a printer that is listening on a TCP/IP or
|
|
other network port.
|
|
|
|
To send data to a networked printer, you need to develop a
|
|
communications program that can be called by the text and
|
|
conversion filters. Here is one such example: the script
|
|
<tt/netprint/ takes all data on standard input and sends
|
|
it to a network-attached printer. We specify the hostname
|
|
of the printer as the first argument and the port number
|
|
to which to connect as the second argument to
|
|
<tt/netprint/. Note that this supports one-way
|
|
communication only (FreeBSD to printer); many network
|
|
printers support two-way communication, and you might want
|
|
to take advantage of that (to get printer status, perform
|
|
accounting, etc.).
|
|
<code>
|
|
#!/usr/bin/perl
|
|
#
|
|
# netprint - Text filter for printer attached to network
|
|
# Installed in /usr/local/libexec/netprint
|
|
#
|
|
|
|
$#ARGV eq 1 || die "Usage: $0 <printer-hostname> <port-number>";
|
|
|
|
$printer_host = $ARGV[0];
|
|
$printer_port = $ARGV[1];
|
|
|
|
require 'sys/socket.ph';
|
|
|
|
($ignore, $ignore, $protocol) = getprotobyname('tcp');
|
|
($ignore, $ignore, $ignore, $ignore, $address)
|
|
= gethostbyname($printer_host);
|
|
|
|
$sockaddr = pack('S n a4 x8', &AF_INET, $printer_port, $address);
|
|
|
|
socket(PRINTER, &PF_INET, &SOCK_STREAM, $protocol)
|
|
|| die "Can't create TCP/IP stream socket: $!";
|
|
connect(PRINTER, $sockaddr) || die "Can't contact $printer_host: $!";
|
|
while (<STDIN>) { print PRINTER; }
|
|
exit 0;
|
|
</code>
|
|
We can then use this script in various filters. Suppose
|
|
we had a Diablo 750-N line printer connected to the
|
|
network. The printer accepts data to print on port number
|
|
5100. The host name of the printer is scrivener. Here is
|
|
the text filter for the printer:
|
|
<code>
|
|
#!/bin/sh
|
|
#
|
|
# diablo-if-net - Text filter for Diablo printer `scrivener' listening
|
|
# on port 5100. Installed in /usr/local/libexec/diablo-if-net
|
|
#
|
|
|
|
exec /usr/libexec/lpr/lpf "$@" | /usr/local/libexec/netprint scrivener 5100
|
|
</code>
|
|
|
|
|
|
<sect1><heading>Restricting Printer Usage<label
|
|
id="printing:advanced:restricting"></heading>
|
|
|
|
<p> This section gives information on restricting printer
|
|
usage. The LPD system lets you control who can access a
|
|
printer, both locally or remotely, whether they can print
|
|
multiple copies, how large their jobs can be, and how large
|
|
the printer queues can get.
|
|
|
|
<sect2><heading>Restricting Multiple Copies<label
|
|
id="printing:advanced:restricting:copies"></heading>
|
|
|
|
<p> The LPD system makes it easy for users to print multiple
|
|
copies of a file. Users can print jobs with <tt/lpr -#5/
|
|
(for example) and get five copies of each file in the job.
|
|
Whether this is a good thing is up to you.
|
|
|
|
If you feel multiple copies cause unnecessary wear and
|
|
tear on your printers, you can disable the <tt/-#/ option
|
|
to <tt/lpr/ by adding the <tt/sc/ capability to the
|
|
<tt>/etc/printcap</tt> file. When users submit jobs
|
|
with the <tt/-#/ option, they will see
|
|
<tscreen><verb>
|
|
lpr: multiple copies are not allowed
|
|
</verb></tscreen>
|
|
|
|
Note that if you have set up access to a printer remotely
|
|
(see section <ref name="Printers Installed on Remote
|
|
Hosts" id="printing:advanced:network:rm">), you need the
|
|
<tt/sc/ capability on the remote <tt>/etc/printcap</tt>
|
|
files as well, or else users will still be able to submit
|
|
multiple-copy jobs by using another host.
|
|
|
|
Here is an example. This is the <tt>/etc/printcap</tt>
|
|
file for the host rose. The printer <tt/rattan/ is quite
|
|
hearty, so we will allow multiple copies, but the laser
|
|
printer <tt/bamboo/'s a bit more delicate, so we will
|
|
disable multiple copies by adding the <tt/sc/ capability:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose - restrict multiple copies on bamboo
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:\
|
|
:lp=/dev/lpt0:\
|
|
:if=/usr/local/libexec/if-simple:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:sc:\
|
|
:lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\
|
|
:if=/usr/local/libexec/psif:\
|
|
:df=/usr/local/libexec/psdf:
|
|
</code>
|
|
Now, we also need to add the <tt/sc/ capability on the
|
|
host orchid's <tt>/etc/printcap</tt> (and while we are at
|
|
it, let us disable multiple copies for the printer
|
|
<tt/teak/):
|
|
<code>
|
|
#
|
|
# /etc/printcap for host orchid - no multiple copies for local
|
|
# printer teak or remote printer bamboo
|
|
|
|
teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\
|
|
:lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:sc:\
|
|
:if=/usr/local/libexec/ifhp:\
|
|
:vf=/usr/local/libexec/vfhp:\
|
|
:of=/usr/local/libexec/ofhp:
|
|
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:sc:
|
|
</code>
|
|
By using the <tt/sc/ capability, we prevent the use of
|
|
<tt/lpr -#/, but that still does not prevent users from
|
|
running <tt/lpr/ multiple times, or from submitting the
|
|
same file multiple times in one job like this:
|
|
<tscreen><verb>
|
|
lpr forsale.sign forsale.sign forsale.sign forsale.sign forsale.sign
|
|
</verb></tscreen>
|
|
There are many ways to prevent this abuse (including
|
|
ignoring it) which you are free to explore.
|
|
|
|
<sect2><heading>Restricting Access To Printers<label
|
|
id="printing:advanced:restricting:access"></heading>
|
|
|
|
<p> You can control who can print to what printers by using
|
|
the UNIX group mechanism and the <tt/rg/ capability in
|
|
<tt>/etc/printcap</tt>. Just place the users you want to
|
|
have access to a printer in a certain group, and then name
|
|
that group in the <tt/rg/ capability.
|
|
|
|
Users outside the group (including root) will be greeted
|
|
with
|
|
<tscreen><verb>
|
|
lpr: Not a member of the restricted group
|
|
</verb></tscreen>
|
|
if they try to print to the controlled printer.
|
|
|
|
As with the <tt/sc/ (suppress multiple copies) capability,
|
|
you need to specify <tt/rg/ on remote hosts that also have
|
|
access to your printers, if you feel it is appropriate (see
|
|
section <ref name="Printers Installed on Remote Hosts"
|
|
id="printing:advanced:network:rm">).
|
|
|
|
For example, we will let anyone access the printer
|
|
<tt/rattan/, but only those in group <tt/artists/ can use
|
|
<tt/bamboo/. Here is the familiar <tt>/etc/printcap</tt>
|
|
for host rose:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose - restricted group for bamboo
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:\
|
|
:lp=/dev/lpt0:\
|
|
:if=/usr/local/libexec/if-simple:
|
|
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:\
|
|
:lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\
|
|
:if=/usr/local/libexec/psif:\
|
|
:df=/usr/local/libexec/psdf:
|
|
</code>
|
|
Let us leave the other example <tt>/etc/printcap</tt> file
|
|
(for the host orchid) alone. Of course, anyone on orchid
|
|
can print to <tt/bamboo/. It might be the case that we
|
|
only allow certain logins on orchid anyway, and want them
|
|
to have access to the printer. Or not.
|
|
|
|
<em/Note:/ there can be only one restricted group per
|
|
printer.
|
|
|
|
<sect2><heading>Controlling Sizes of Jobs Submitted<label
|
|
id="printing:advanced:restricting:sizes"></heading>
|
|
|
|
<p> If you have many users accessing the printers, you
|
|
probably need to put an upper limit on the sizes of the
|
|
files users can submit to print. After all, there is only
|
|
so much free space on the filesystem that houses the
|
|
spooling directories, and you also need to make sure
|
|
there is room for the jobs of other users.
|
|
|
|
LPD enables you to limit the maximum byte size a file in a
|
|
job can be with the <tt/mx/ capability. The units are in
|
|
BUFSIZ blocks, which are 1024 bytes. If you put a zero
|
|
for this capability, there will be no limit on file size.
|
|
Note that the limit applies to <em/files/ in a job, and
|
|
<em/not/ the total job size.
|
|
|
|
LPD will not refuse a file that is larger than the limit you
|
|
place on a printer. Instead, it will queue as much of the
|
|
file up to the limit, which will then get printed. The
|
|
rest will be discarded. Whether this is correct behavior
|
|
is up for debate.
|
|
|
|
Let us add limits to our example printers <tt/rattan/ and
|
|
<tt/bamboo/. Since those artists' PostScript files tend
|
|
to be large, we will limit them to five megabytes. We will
|
|
put no limit on the plain text line printer:
|
|
<code>
|
|
#
|
|
# /etc/printcap for host rose
|
|
#
|
|
|
|
#
|
|
# No limit on job size:
|
|
#
|
|
rattan|line|diablo|lp|Diablo 630 Line Printer:\
|
|
:sh:sd=/var/spool/lpd/rattan:\
|
|
:lp=/dev/lpt0:\
|
|
:if=/usr/local/libexec/if-simple:
|
|
|
|
#
|
|
# Limit of five megabytes:
|
|
#
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\
|
|
:lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\
|
|
:if=/usr/local/libexec/psif:\
|
|
:df=/usr/local/libexec/psdf:
|
|
</code>
|
|
Again, the limits apply to the local users only. If
|
|
you have set up access to your printers remotely, remote
|
|
users will not get those limits. You will need to specify the
|
|
<tt/mx/ capability in the remote <tt>/etc/printcap</tt>
|
|
files as well. See section <ref name="Printers Installed
|
|
on Remote Hosts" id="printing:advanced:network:rm"> for
|
|
more information on remote printing.
|
|
|
|
There is another specialized way to limit job sizes from
|
|
remote printers; see section <ref
|
|
id="printing:advanced:restricting:remote"
|
|
name="Restricting Jobs from Remote Printers">.
|
|
|
|
<sect2><heading>Restricting Jobs from Remote Printers<label
|
|
id="printing:advanced:restricting:remote"></heading>
|
|
|
|
<p> The LPD spooling system provides several ways to restrict
|
|
print jobs submitted from remote hosts:
|
|
|
|
<descrip>
|
|
<tag/Host restrictions/
|
|
|
|
You can control from which remote hosts a local LPD
|
|
accepts requests with the files
|
|
<tt>/etc/hosts.equiv</tt> and <tt>/etc/hosts.lpd</tt>.
|
|
LPD checks to see if an incoming request is from a
|
|
host listed in either one of these files. If not, LPD
|
|
refuses the request.
|
|
|
|
The format of these files is simple: one host name per
|
|
line. Note that the file <tt>/etc/hosts.equiv</tt> is
|
|
also used by the ruserok(3) protocol, and affects
|
|
programs like <tt/rsh/ and <tt/rcp/, so be careful.
|
|
|
|
For example, here is the <tt>/etc/hosts.lpd</tt> file
|
|
on the host rose:
|
|
<code>
|
|
orchid
|
|
violet
|
|
madrigal.fishbaum.de
|
|
</code>
|
|
This means rose will accept requests from the hosts
|
|
orchid, violet, and madrigal.fishbaum.de. If any
|
|
other host tries to access rose's LPD, LPD will
|
|
refuse them.
|
|
|
|
<tag/Size restrictions/
|
|
|
|
You can control how much free space there needs to
|
|
remain on the filesystem where a spooling directory
|
|
resides. Make a file called <tt/minfree/ in the
|
|
spooling directory for the local printer. Insert in
|
|
that file a number representing how many disk blocks
|
|
(512 bytes) of free space there has to be for a remote
|
|
job to be accepted.
|
|
|
|
This lets you insure that remote users will not fill your
|
|
filesystem. You can also use it to give a certain
|
|
priority to local users: they will be able to queue jobs
|
|
long after the free disk space has fallen below the
|
|
amount specified in the <tt/minfree/ file.
|
|
|
|
For example, let us add a <tt/minfree/ file for the
|
|
printer <tt/bamboo/. We examine
|
|
<tt>/etc/printcap</tt> to find the spooling directory
|
|
for this printer; here is <tt/bamboo/'s entry:
|
|
<tscreen><verb>
|
|
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
|
|
:sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\
|
|
:lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:mx#5000:\
|
|
:if=/usr/local/libexec/psif:\
|
|
:df=/usr/local/libexec/psdf:
|
|
</verb></tscreen>
|
|
The spooling directory is the given in the <tt/sd/
|
|
capability. We will make three megabytes (which is 6144
|
|
disk blocks) the amount of free disk space that must
|
|
exist on the filesystem for LPD to accept remote jobs:
|
|
<tscreen><verb>
|
|
echo 6144 > /var/spool/lpd/bamboo/minfree
|
|
</verb></tscreen>
|
|
<tag/User restrictions/
|
|
|
|
You can control which remote users can print to local
|
|
printers by specifying the <tt/rs/ capability in
|
|
<tt>/etc/printcap</tt>. When <tt/rs/ appears in the
|
|
entry for a locally-attached printer, LPD will accept
|
|
jobs from remote hosts <em/if/ the user submitting the
|
|
job also has an account of the same login name on the
|
|
local host. Otherwise, LPD refuses the job.
|
|
|
|
This capability is particularly useful in an
|
|
environment where there are (for example) different
|
|
departments sharing a network, and some users
|
|
transcend departmental boundaries. By giving them
|
|
accounts on your systems, they can use your printers
|
|
from their own departmental systems. If you would rather
|
|
allow them to use <em/only/ your printers and not your
|
|
compute resources, you can give them ``token''
|
|
accounts, with no home directory and a useless shell
|
|
like <tt>/usr/bin/false</tt>.
|
|
</descrip>
|
|
|
|
<sect1><heading>Accounting for Printer Usage<label
|
|
id="printing:advanced:acct"></heading>
|
|
|
|
<p> So, you need to charge for printouts. And why not? Paper
|
|
and ink cost money. And then there are maintenance
|
|
costs---printers are loaded with moving parts and tend to
|
|
break down. You have examined your printers, usage patterns,
|
|
and maintenance fees and have come up with a per-page (or
|
|
per-foot, per-meter, or per-whatever) cost. Now, how do you
|
|
actually start accounting for printouts?
|
|
|
|
Well, the bad news is the LPD spooling system does not
|
|
provide much help in this department. Accounting is highly
|
|
dependent on the kind of printer in use, the formats being
|
|
printed, and <em/your/ requirements in charging for printer
|
|
usage.
|
|
|
|
To implement accounting, you have to modify a printer's text
|
|
filter (to charge for plain text jobs) and the conversion
|
|
filters (to charge for other file formats), to count pages
|
|
or query the printer for pages printed. You cannot get away
|
|
with using the simple output filter, since it cannot do
|
|
accounting. See section <ref name="Filters"
|
|
id="printing:advanced:filter-intro">.
|
|
|
|
Generally, there are two ways to do accounting:
|
|
<itemize>
|
|
<item><em/Periodic accounting/ is the more common way,
|
|
possibly because it is easier. Whenever someone prints a
|
|
job, the filter logs the user, host, and number of pages
|
|
to an accounting file. Every month, semester, year, or
|
|
whatever time period you prefer, you collect the
|
|
accounting files for the various printers, tally up the
|
|
pages printed by users, and charge for usage. Then you
|
|
truncate all the logging files, starting with a clean
|
|
slate for the next period.
|
|
|
|
<item><em/Timely accounting/ is less common, probably
|
|
because it is more difficult. This method has the
|
|
filters charge users for printouts as soon as they use
|
|
the printers. Like disk quotas, the accounting is
|
|
immediate. You can prevent users from printing when
|
|
their account goes in the red, and might provide a way
|
|
for users to check and adjust their ``print quotas.''
|
|
But this method requires some database code to track
|
|
users and their quotas.
|
|
</itemize>
|
|
|
|
The LPD spooling system supports both methods easily: since
|
|
you have to provide the filters (well, most of the time),
|
|
you also have to provide the accounting code. But there is
|
|
a bright side: you have enormous flexibility in your
|
|
accounting methods. For example, you choose whether to use
|
|
periodic or timely accounting. You choose what information
|
|
to log: user names, host names, job types, pages printed,
|
|
square footage of paper used, how long the job took to
|
|
print, and so forth. And you do so by modifying the filters
|
|
to save this information.
|
|
|
|
<sect2><heading>Quick and Dirty Printer Accounting</heading>
|
|
|
|
<p> FreeBSD comes with two programs that can get you set up
|
|
with simple periodic accounting right away. They are the
|
|
text filter <tt/lpf/, described in section <ref
|
|
id="printing:advanced:lpf" name="lpf: a Text Filter">, and
|
|
<tt/pac/, a program to gather and total entries from
|
|
printer accounting files.
|
|
|
|
As mentioned in the section on filters (<ref
|
|
id="printing:advanced:filters" name="Filters">), LPD
|
|
starts the text and the conversion filters with the name
|
|
of the accounting file to use on the filter command
|
|
line. The filters can use this argument to know where
|
|
to write an accounting file entry. The name of this
|
|
file comes from the <tt/af/ capability in
|
|
<tt>/etc/printcap</tt>, and if not specified as an
|
|
absolute path, is relative to the spooling directory.
|
|
|
|
LPD starts <tt/lpf/ with page width and length arguments
|
|
(from the <tt/pw/ and <tt/pl/ capabilities). <tt/lpf/
|
|
uses these arguments to determine how much paper will be
|
|
used. After sending the file to the printer, it then
|
|
writes an accounting entry in the accounting file. The
|
|
entries look like this:
|
|
<tscreen><verb>
|
|
2.00 rose:andy
|
|
3.00 rose:kelly
|
|
3.00 orchid:mary
|
|
5.00 orchid:mary
|
|
2.00 orchid:zhang
|
|
</verb></tscreen>
|
|
You should use a separate accounting file for each
|
|
printer, as <tt/lpf/ has no file locking logic built into
|
|
it, and two <tt/lpf/s might corrupt each other's entries
|
|
if they were to write to the same file at the same time.
|
|
A easy way to insure a separate accounting file for each
|
|
printer is to use <tt/af=acct/ in <tt>/etc/printcap</tt>.
|
|
Then, each accounting file will be in the spooling directory
|
|
for a printer, in a file named <tt/acct/.
|
|
|
|
When you are ready to charge users for printouts, run the
|
|
<tt/pac/ program. Just change to the spooling directory
|
|
for the printer you want to collect on and type <tt/pac/.
|
|
You will get a dollar-centric summary like the following:
|
|
<code>
|
|
Login pages/feet runs price
|
|
orchid:kelly 5.00 1 $ 0.10
|
|
orchid:mary 31.00 3 $ 0.62
|
|
orchid:zhang 9.00 1 $ 0.18
|
|
rose:andy 2.00 1 $ 0.04
|
|
rose:kelly 177.00 104 $ 3.54
|
|
rose:mary 87.00 32 $ 1.74
|
|
rose:root 26.00 12 $ 0.52
|
|
|
|
total 337.00 154 $ 6.74
|
|
</code>
|
|
These are the arguments <tt/pac/ expects:
|
|
<descrip>
|
|
<tag/<tt/-P<it/printer///
|
|
|
|
Which <it/printer/ to summarize. This option works
|
|
only if there is an absolute path in the <tt/af/
|
|
capability in <tt>/etc/printcap</tt>.
|
|
|
|
<tag/<tt/-c//
|
|
|
|
Sort the output by cost instead of alphabetically by
|
|
user name.
|
|
|
|
<tag/<tt/-m//
|
|
|
|
Ignore host name in the accounting files. With this
|
|
option, user smith on host alpha is the same user
|
|
smith on host gamma. Without, they are different users.
|
|
|
|
<tag/<tt/-p<it/price///
|
|
|
|
Compute charges with <it/price/ dollars per page or
|
|
per foot instead of the price from the <tt/pc/
|
|
capability in <tt>/etc/printcap</tt>, or two cents (the
|
|
default). You can specify <it/price/ as a floating
|
|
point number.
|
|
|
|
<tag/<tt/-r//
|
|
|
|
Reverse the sort order.
|
|
|
|
<tag/<tt/-s//
|
|
|
|
Make an accounting summary file and truncate the
|
|
accounting file.
|
|
|
|
<tag/<tt/<it/names...///
|
|
|
|
Print accounting information for the given user
|
|
<it/names/ only.
|
|
</descrip>
|
|
|
|
In the default summary that <tt/pac/ produces, you see the
|
|
number of pages printed by each user from various hosts.
|
|
If, at your site, host does not matter (because users can
|
|
use any host), run <tt/pac -m/, to produce the following
|
|
summary:
|
|
<code>
|
|
Login pages/feet runs price
|
|
andy 2.00 1 $ 0.04
|
|
kelly 182.00 105 $ 3.64
|
|
mary 118.00 35 $ 2.36
|
|
root 26.00 12 $ 0.52
|
|
zhang 9.00 1 $ 0.18
|
|
|
|
total 337.00 154 $ 6.74
|
|
</code>
|
|
To compute the dollar amount due, <tt/pac/ uses the
|
|
<tt/pc/ capability in the <tt>/etc/printcap</tt> file
|
|
(default of 200, or 2 cents per page). Specify, in
|
|
hundredths of cents, the price per page or per foot you
|
|
want to charge for printouts in this capability. You can
|
|
override this value when you run <tt/pac/ with the <tt/-p/
|
|
option. The units for the <tt/-p/ option are in dollars,
|
|
though, not hundredths of cents. For example,
|
|
<tscreen><verb>
|
|
pac -p1.50
|
|
</verb></tscreen>
|
|
makes each page cost one dollar and fifty cents. You can
|
|
really rake in the profits by using this option.
|
|
|
|
Finally, running <tt/pac -s/ will save the summary
|
|
information in a summary accounting file, which is named
|
|
the same as the printer's accounting file, but with
|
|
<tt/_sum/ appended to the name. It then truncates the
|
|
accounting file. When you run <tt/pac/ again, it rereads
|
|
the summary file to get starting totals, then adds
|
|
information from the regular accounting file.
|
|
|
|
|
|
<sect2><heading>How Can You Count Pages Printed?</heading>
|
|
|
|
<p> In order to perform even remotely accurate accounting,
|
|
you need to be able to determine how much paper a job
|
|
uses. This is the essential problem of printer
|
|
accounting.
|
|
|
|
For plain text jobs, the problem's not that hard to solve:
|
|
you count how many lines are in a job and compare it to
|
|
how many lines per page your printer supports. Do not
|
|
forget to take into account backspaces in the file which
|
|
overprint lines, or long logical lines that wrap onto one
|
|
or more additional physical lines.
|
|
|
|
The text filter <tt/lpf/ (introduced in <ref
|
|
id="printing:advanced:lpf" name="lpf: a Text Filter">)
|
|
takes into account these things when it does accounting.
|
|
If you are writing a text filter which needs to do
|
|
accounting, you might want to examine <tt/lpf/'s source
|
|
code.
|
|
|
|
How do you handle other file formats, though?
|
|
|
|
Well, for DVI-to-LaserJet or DVI-to-PostScript conversion,
|
|
you can have your filter parse the diagnostic output of
|
|
<tt/dvilj/ or <tt/dvips/ and look to see how many pages
|
|
were converted. You might be able to do similar things
|
|
with other file formats and conversion programs.
|
|
|
|
But these methods suffer from the fact that the printer
|
|
may not actually print all those pages. For example, it
|
|
could jam, run out of toner, or explode---and the user
|
|
would still get charged.
|
|
|
|
So, what can you do?
|
|
|
|
There is only one <em/sure/ way to do <em/accurate/
|
|
accounting. Get a printer that can tell you how much
|
|
paper it uses, and attach it via a serial line or a
|
|
network connection. Nearly all PostScript printers
|
|
support this notion. Other makes and models do as well
|
|
(networked Imagen laser printers, for example). Modify
|
|
the filters for these printers to get the page usage after
|
|
they print each job and have them log accounting
|
|
information based on that value <em/only/. There is no
|
|
line counting nor error-prone file examination required.
|
|
|
|
Of course, you can always be generous and make all
|
|
printouts free.
|
|
|
|
<sect><heading>Alternatives to the Standard Spooler<label
|
|
id="printing:lpd-alternatives"></heading>
|
|
|
|
<p> If you have been reading straight through this manual, by now
|
|
you have learned just about everything there is to know about
|
|
the LPD spooling system that comes with FreeBSD. You can
|
|
probably appreciate many of its shortcomings, which naturally
|
|
leads to the question: ``What other spooling systems are out
|
|
there (and work with FreeBSD)?''
|
|
|
|
Unfortunately, I have located only <em/two/ alternatives---and
|
|
they are almost identical to each other! They are:
|
|
<descrip>
|
|
<tag/PLP, the Portable Line Printer Spooler System/
|
|
|
|
PLP was based on software developed by Patrick Powell and
|
|
then maintained by an Internet-wide group of developers.
|
|
The main site for the software is at <htmlurl
|
|
url="ftp://ftp.iona.ie/pub/plp"
|
|
name="ftp://ftp.iona.ie/pub/plp">. There is also a <htmlurl
|
|
url="http://www.iona.ie:8000/www/hyplan/jmason/plp.html"
|
|
name="web page">.
|
|
|
|
It is quite similar to the BSD LPD spooler, but boasts a
|
|
host of features, including:
|
|
<itemize>
|
|
<item>Better network support, including built-in support
|
|
for networked printers, NIS-maintained printcaps, and
|
|
NFS-mounted spooling directories
|
|
|
|
<item>Sophisticated queue management, allowing multiple
|
|
printers on a queue, transfer of jobs between queues,
|
|
and queue redirection
|
|
|
|
<item>Remote printer control functions
|
|
|
|
<item>Prioritization of jobs
|
|
|
|
<item>Expansive security and access options
|
|
</itemize>
|
|
|
|
<tag/LPRng/
|
|
|
|
LPRng, which purportedly means ``LPR: the Next
|
|
Generation'' is a complete rewrite of PLP. Patrick Powell
|
|
and Justin Mason (the principal maintainer of PLP)
|
|
collaborated to make LPRng. The main site for LPRng is
|
|
<htmlurl url="ftp://dickory.sdsu.edu/pub/LPRng"
|
|
name="ftp://dickory.sdsu.edu/pub/LPRng">.
|
|
</descrip>
|
|
|
|
|
|
<sect><heading>Acknowledgments</heading>
|
|
|
|
<p> I would like to thank the following people who have assisted in
|
|
the development of this document:
|
|
|
|
<descrip>
|
|
<tag/Daniel Eischen <tt/<deischen@iworks.interworks.org>//
|
|
|
|
For providing a plethora of HP filter programs for perusal.
|
|
|
|
<tag/&a.jehamby;/
|
|
|
|
For the Ghostscript-to-HP filter.
|
|
|
|
<tag/My wife, Mary Kelly <tt/<urquhart@argyre.colorado.edu>//
|
|
|
|
For allowing me to spend more time with FreeBSD than with her.
|
|
|
|
</descrip>
|