Added a very complete new chapter on printing.

This brings the printed handbook to ~275 pages.
Submitted by:	Sean Kelly <kelly@fsl.noaa.gov>

5 files changed, 3893 insertions, 7 deletions

diff --git a/share/doc/handbook/Makefile b/share/doc/handbook/Makefile
index 369bc85..ec54798 100644
--- a/share/doc/handbook/Makefile
+++ b/share/doc/handbook/Makefile
@@ -1,11 +1,12 @@
-# $Id: Makefile,v 1.2 1995/09/25 04:53:26 jfieber Exp $
+# $Id: Makefile,v 1.3 1995/09/25 18:23:02 wollman Exp $
 
 SRCS= authors.sgml basics.sgml bibliography.sgml boothelp.sgml
 SRCS+= booting.sgml contrib.sgml crypt.sgml ctm.sgml current.sgml dialup.sgml
 SRCS+= diskless.sgml dma.sgml eresources.sgml esdi.sgml glossary.sgml
 SRCS+= handbook.sgml history.sgml hw.sgml install.sgml kerberos.sgml
 SRCS+= kerneldebug.sgml memoryuse.sgml mirrors.sgml nfs.sgml nutshell.sgml 
-SRCS+= porting.sgml ports.sgml ppp.sgml relnotes.sgml scsi.sgml sections.sgml
+SRCS+= porting.sgml ports.sgml ppp.sgml printing.sgml relnotes.sgml 
+SRCS+= scsi.sgml sections.sgml
 SRCS+= skey.sgml slipc.sgml slips.sgml submitters.sgml sup.sgml
 SRCS+= troubleshooting.sgml userppp.sgml
 
diff --git a/share/doc/handbook/authors.sgml b/share/doc/handbook/authors.sgml
index a81b401..72b0258 100644
--- a/share/doc/handbook/authors.sgml
+++ b/share/doc/handbook/authors.sgml
@@ -1,4 +1,4 @@
-<!-- $Id: authors.sgml,v 1.7 1995/08/27 02:44:16 jfieber Exp $ -->
+<!-- $Id: authors.sgml,v 1.8 1995/09/25 04:53:27 jfieber Exp $ -->
 <!-- The FreeBSD Documentation Project -->
 
 <!-- 
@@ -55,6 +55,10 @@ and double quotes.
   <tt><htmlurl url='mailto:john@starfire.MN.ORG' 
   name='&lt;john@starfire.MN.ORG&gt;'></tt>">
 
+<!ENTITY a.kelly "Sean Kelly
+  <tt><htmlurl url='mailto:kelly@fsl.noaa.gov'
+  name='&lt;kelly@fsl.noaa.gov&gt;'></tt>">
+
 <!ENTITY a.mark "Mark Murray 
   <tt><htmlurl url='mailto:mark@grondar.za' 
   name='&lt;mark@grondar.za&gt;'></tt>">
diff --git a/share/doc/handbook/handbook.sgml b/share/doc/handbook/handbook.sgml
index a0d6df4..6235945 100644
--- a/share/doc/handbook/handbook.sgml
+++ b/share/doc/handbook/handbook.sgml
@@ -1,4 +1,4 @@
-<!-- $Id: handbook.sgml,v 1.29 1995/09/25 18:23:03 wollman Exp $ -->
+<!-- $Id: handbook.sgml,v 1.30 1995/09/27 00:46:19 jmz Exp $ -->
 <!-- The FreeBSD Documentation Project -->
 
 <!DOCTYPE linuxdoc PUBLIC "-//FreeBSD//DTD linuxdoc//EN" [
@@ -24,7 +24,7 @@
       <author>
 	<name>The FreeBSD Documentation Project</name>
       </author>
-      <date>September 24, 1995</date>
+      <date>September 30, 1995</date>
 
 <abstract>Welcome to FreeBSD!  This handbook covers the
 installation and day to day use of <bf>FreeBSD Release
@@ -80,11 +80,13 @@ Web server">.
       &kerberos;
       <sect><heading>* Firewalls</heading>
 
+    &printing;
+<!--
     <chapt><heading>Printing</heading>
       <p>This section is in progress.  Please contact
         Sean Kelly <url url="mailto:kelly@fsl.noaa.gov"
         name="kelley@fsl.noaa.gov"> for more information.
-
+-->
     <chapt><heading>The X-Window System</heading>
        <p>Pending the completion of this section, please refer to
          documentation supplied by the <url url="http://www.xfree86.org/"
diff --git a/share/doc/handbook/printing.sgml b/share/doc/handbook/printing.sgml
new file mode 100644
index 0000000..575c196
--- /dev/null
+++ b/share/doc/handbook/printing.sgml
@@ -0,0 +1,3878 @@
+<!-- This is an SGML document in the linuxdoc DTD describing
+     Printing with FreeBSD.  By Sean Kelly, 1995.
+
+     $Id$
+
+     The FreeBSD Documentation Project
+
+<!DOCTYPE linuxdoc PUBLIC "-//FreeBSD//DTD linuxdoc//EN">
+
+  <article>
+      <title> Printing with FreeBSD
+      <author> Sean Kelly <tt/kelly@fsl.noaa.gov/
+      <date> 30 September 1995, (c) 1995
+
+      <abstract> This document describes printing with FreeBSD.  It
+	tells how to set up printer hardware, how to configure FreeBSD
+	to use printers, and how to control the print queue and print
+	a variety of file formats. </abstract>
+
+    <toc>
+-->
+
+  <chapt><heading>Printing<label id="printing"></heading>
+
+    <p><em>Contributed by &a.kelly;<newline>30 September 1995</em>
+
+        In order to use printers with FreeBSD, you'll need to set
+	them up to work with the Berkeley line printer spooling
+	system, also known as the LPD spooling system.  It's the
+	standard printer control system in FreeBSD.  This section
+	introduces the LPD spooling system, often simply called LPD.
+
+	If you're already familiar with LPD or another printer
+	spooling system, you may wish to skip to section <ref
+	id="printing:intro:setup" name="Setting up the spooling
+	system">.
+
+      <sect><heading>What the Spooler Does<label
+	    id="printing:intro:spooler"></heading>
+
+	<p> LPD controls everything about a host's printers.  It's
+	  responsible for a number of things:
+
+	  <itemize>
+	    <item>It controls access to attached printers and
+	      printers attached to other hosts on the network.
+
+	    <item>It enables users to submit files to be printed;
+	      these submissions are known as <em/jobs/.
+
+	    <item>It prevents multiple users from accessing a printer
+	      at the same time by maintaining a <em/queue/ for each
+	      printer.
+
+	    <item>It can print <em/header pages/ (also known as
+	      <em/banner/ or <em/burst/ pages) so users can easily
+	      find jobs they've printed in a stack of printouts.
+
+	    <item>It takes care of communications parameters for
+	      printers connected on serial ports.
+
+	    <item>It can send jobs over the network to another LPD
+	      spooler on another host.
+
+	    <item>It can run special filters to format jobs to be
+	      printed for various printer languages or printer
+	      capabilities.
+
+	    <item>It can account for printer usage.
+	  </itemize>
+
+	  Through a configuration file, and by providing the special
+	  filter programs, you can enable the LPD system to do all or
+	  some subset of the above for a great variety of printer
+	  hardware.
+
+      <sect><heading>Why You Should Use the Spooler<label
+	    id="printing:intro:why"></heading> 
+
+	<p> If you're the sole user of your system, you may be
+	  wondering why you should bother with the spooler when you
+	  don't need access control, header pages, or printer
+	  accounting.  While it's possible to enable direct access to
+	  a printer, you should use the spooler anyway since
+
+	  <itemize>
+	    <item>LPD prints jobs in the background; you don't have
+	      to wait for data to be copied to the printer.
+
+	    <item>LPD can conveniently run a job to be printed
+	      through filters to add date/time headers or convert a
+	      special file format (such as a TeX DVI file) into a
+	      format the printer will understand.   You won't have to do
+	      these steps manually.
+
+	    <item>Many free and commercial programs that provide a
+	      print feature usually expect to talk to the spooler on
+	      your system.  By setting up the spooling system, you'll
+	      more easily support other software you may later add or
+	      already have.
+	  </itemize>
+
+      <sect><heading>Setting Up the Spooling System<label
+	    id="printing:intro:setup"></heading>
+
+	<p> To use printers with the LPD spooling system, you'll need
+	  to set up both your printer hardware and the LPD software.
+	  This document describes two levels of setup:
+
+	  <itemize>
+	    <item>See section <ref name="Simple Printer Setup"
+		id="printing:simple"> to learn how to connect a
+		printer, tell LPD how to communicate with it, and
+		print plain text files to the printer.
+
+	    <item>See section <ref name="Advanced Printer Setup"
+		id="printing:advanced"> to find out how to print a
+		variety of special file formats, to print header
+		pages, to print across a network, to control access to
+		printers, and to do printer accounting.
+	  </itemize>
+
+
+    <sect><heading>Simple Printer Setup<label
+	  id="printing:simple"></heading>
+
+      <p> This section tells how to configure printer hardware and the
+	LPD software to use the printer.  It teaches the basics:
+
+	<itemize>
+	  <item>Section <ref id="printing:hardware" name="Hardware
+	    Setup"> gives some hints on connecting the printer to a
+	    port on your computer.
+
+	  <item>Section <ref id="printing:software" name="Software
+	    Setup"> shows how to setup the LPD spooler configuration
+	    file <tt>/etc/printcap</tt>.
+	</itemize>
+
+        If you're setting up a printer that uses a network protocol
+	to accept data to print instead of a serial or parallel interface,
+	see <ref id="printing:advanced:network:net-if" name="Printers
+	  With Networked Data Stream Interaces">.
+
+	Although this section is called ``Simple Printer Setup,'' it's
+	actually fairly complex.  Getting the printer to work with
+	your computer and the LPD spooler is the hardest part.  The
+	advanced options like header pages and accounting are fairly
+	easy once you get the printer working.
+
+      <sect1><heading>Hardware Setup<label id="printing:hardware"></heading>
+
+	<p> This section tells about the various ways you can connect a
+	  printer to your PC.  It talks about the kinds of ports and
+	  cables, and also the kernel configuration you may need to
+	  enable FreeBSD to speak to the printer.
+
+	  If you've already connected your printer and have
+	  successfully printed with it under another operating system,
+	  you can probably skip to section <ref id="printing:software"
+	  name="Software Setup">.
+
+	<sect2><heading>Ports and Cables<label
+	      id="printing:ports"></heading> 
+
+	  <p> Nearly all printers you can get for a PC today support
+	    one or both of the following interfaces:
+
+	    <itemize>
+	      <item><em/Serial/ interfaces use a serial port on your
+		computer to send data to the printer.  Serial
+		interfaces are common in the computer industry and
+		cables are readily available and also easy to
+		construct.  Serial interfaces sometimes need special
+		cables and might require you to configure somewhat
+		complex communications options.
+
+	      <item><em/Parallel/ interfaces use a parallel port on
+		your computer to send data to the printer.  Parallel
+		interfaces are common in the PC market.  Cables are
+		readily available but more difficult to construct by
+		hand.  There are usually no communications options
+		with parallel interfaces, making their configuration
+		exceedingly simple.
+
+		<p> Parallel interfaces are sometimes known as
+		  ``Centronics'' interfaces, named after the connector
+		  type on the printer.
+	    </itemize>
+
+	    In general, serial interfaces are slower than parallel
+	    interfaces.  Parallel interfaces usually offer just
+	    one-way communication (computer to printer) while serial
+	    gives you two-way.  Many newer parallel ports can also
+	    receive data from the printer, but only few printers need
+	    to send data back to the computer.  And FreeBSD doesn't
+	    support two-way parallel communication yet.
+
+	    Usually, the only time you need two-way communication with
+	    the printer is if the printer speaks PostScript.
+	    PostScript printers can be very verbose.  In fact,
+	    PostScript jobs are actually programs sent to the printer;
+	    they needn't produce paper at all and may return results
+	    directly to the computer.  PostScript also uses
+	    two-way communication to tell the computer about problems,
+	    such as errors in the PostScript program or paper jams.
+	    Your users may be appreciative of such information.
+	    Furthermore, the best way to do effective accounting with
+	    a PostScript printer requires two-way communication: you
+	    ask the printer for its page count (how many pages it's
+	    printed in its lifetime), then send the user's job, then
+	    ask again for its page count. Subtract the two values and
+	    you know how much paper to charge the user.
+
+	    So, which interface should you use?
+
+	    <itemize>
+	      <item>If you need two-way communication, use a serial
+		port.  FreeBSD does not yet support two-way
+		communication over a parallel port.
+
+	      <item>If you don't need two-way communication and can
+		pick parallel or serial, prefer the parallel
+		interface.  It keeps a serial port free for other
+		peripherals---such as a terminal or a modem---and is
+		faster most of the time.  It's also easier to
+		configure.
+
+	      <item>Finally, use whatever works.	
+	    </itemize>
+
+
+	<sect2><heading>Parallel Ports<label id="printing:parallel"></heading>
+
+	  <p> To hook up a printer using a parallel interface, connect
+	    the Centronics cable between the printer and the
+	    computer. The instructions that came with the printer, the
+	    computer, or both should give you complete guidance.
+
+	    Remember which parallel port you used on the computer. The
+	    first parallel port is /dev/lpt0 to FreeBSD; the second is
+	    /dev/lpt1, and so on.
+
+	<sect2><heading>Serial Ports<label id="printing:serial"></heading>
+
+	  <p> To hook up a printer using a serial interface, connect
+	    the proper serial cable between the printer and the
+	    computer.  The instructions that came with the printer,
+	    the computer, or both should give you complete guidance.
+
+	    If you're unsure what the ``proper serial cable'' is, you
+	    may wish to try one of the following alternatives:
+	    <itemize>
+	      <item>A <em/modem/ cable connects each pin of the
+		connector on one end of the cable straight through to
+		its corresponding pin of the connector on the other
+		end.  This type of cable is also known as a DTE-to-DCE
+		cable.
+
+	      <item>A <em/null-modem/ cable connects some pins
+		straight through, swaps others (send data to receive
+		data, for example), and shorts some internally in each
+		connector hood.  This type of cable is also known as a
+		DTE-to-DTE cable.
+
+	      <item>A <em/serial printer/ cable, required for some
+		unusual printers, is like the null modem cable, but
+		sends some signals to their counterparts instead of
+		being internally shorted.
+	    </itemize>
+
+	    You should also set up the communications parameters for
+	    the printer, usually through front-panel controls or DIP
+	    switches on the printer.  Choose the highest bps (bits per
+	    second, sometimes <em/baud rate/) rate that both your
+	    computer and the printer can support.  Choose 7 or 8 data
+	    bits; none, even, or odd parity; and 1 or 2 stop bits.
+	    Also choose a flow control protocol: either none, or
+	    XON/XOFF (also known as <em/in-band/ or <em/software/)
+	    flow control.  Remember these settings for the software
+	    configuration that follows.
+
+      <sect1><heading>Software Setup<label id="printing:software"></heading>
+
+	<p> This section describes the software setup necessary to
+	  print with the LPD spooling system in FreeBSD.
+
+	  Here's an outline of the steps involved:
+	  <enum>
+	    <item>Configure your kernel, if necessary, for the port
+	      you're using for the printer; section <ref
+	      id="printing:kernel" name="Kernel Configuration"> tells
+	      you what you need to do.
+
+	    <item>Set the communications mode for the parallel port,
+	      if you're using a parallel port; section <ref
+	      id="printing:parallel-port-mode" name = "Setting the
+	      Communication Mode for the Parallel Port"> gives
+	      details.
+
+	    <item>Test if the operating system can send data to the
+	      printer.  Section <ref id="printing:testing"
+	      name="Checking Printer Communications"> gives some
+	      suggestions on how to do this.
+
+	    <item>Set up LPD for the printer by modifying the file
+	      <tt>/etc/printcap</tt>.  Section <ref
+	      id="printing:printcap" name="The /etc/printcap File">
+	      shows you how.
+	  </enum>
+
+	<sect2><heading>Kernel Configuration<label
+	      id="printing:kernel"></heading>
+
+	  <p> The operating system kernel is compiled to work with a
+	    specific set of devices.  The serial or parallel interface
+	    for your printer is a part of that set.  Therefore, it
+	    might be necessary to add support for an additional serial
+	    or parallel port if your kernel isn't already configured
+	    for one.
+
+	    To find out if the kernel you're currently using supports a serial
+	    interface, type
+<tscreen>
+<tt>dmesg &verbar; grep sio</tt><it/N/
+</tscreen>
+	    where <it/N/ is the number of the serial port, starting
+	    from zero.  If you see output similar to the following
+<tscreen><verb> 
+sio2 at 0x3e8-0x3ef irq 5 on isa
+sio2: type 16550A
+</verb></tscreen>
+	    then the kernel supports the port.
+
+	    To find out if the kernel supports a parallel interface,
+	    type
+<tscreen>
+<tt>dmesg &verbar; grep lpt</tt><it/N/
+</tscreen>
+	    where <it/N/ is the number of the parallel port, starting
+	    from zero.  If you see output similar to the following
+<tscreen><verb>
+lpt0 at 0x378-0x37f on isa
+</verb></tscreen>
+	    then the kernel supports the port.
+
+	    You might have to reconfigure your kernel in order for the
+	    operating system to recognize and use the parallel or
+	    serial port you're using for the printer.
+
+	    To add support for a serial port, see the section on
+            kernel configuration.  To add support for a parallel port,
+            see that section <em/and/ the section that follows.
+
+	  <sect3><heading>Adding <tt>/dev</tt> Entries for the Ports
+	      <label id="printing:dev-ports"></heading>
+
+	    <p> Even though the kernel may support communication along
+	      a serial or parallel port, you'll still need a software
+	      interface through which programs running on the system
+	      can send and receive data.  That's what entries in the
+	      <tt>/dev</tt> directory are for.
+
+	      <bf>To add a <tt>/dev</tt> entry for a port:</bf>
+	      <enum>
+		<item>Become root with the <tt/su/ command.  Enter
+		  the root password when prompted.
+
+		<item>Change to the <tt>/dev</tt> directory:
+<tscreen><verb>
+cd /dev
+</verb></tscreen>
+
+		<item>Type
+<tscreen>
+<tt> ./MAKEDEV</tt> <it/port/
+</tscreen>
+		  where <it/port/ is the device entry for the port you
+		  want to make.  Use <tt/lpt0/ for the first parallel
+		  port, <tt/lpt1/ for the second, and so on; use
+		  <tt/ttyd0/ for the first serial port, <tt/ttyd1/ for
+		  the second, and so on.
+
+		<item>Type
+<tscreen>
+<tt>ls -l</tt> <it/port/
+</tscreen>
+		  to make sure the device entry got created.
+	      </enum>
+
+	  <sect3><heading>Setting the Communication Mode for the Parallel Port
+	      <label id="printing:parallel-port-mode"></heading>
+
+	    <p> When you're using the parallel interface, you can
+	      choose whether FreeBSD should use interrupt-driven or
+	      polled communication with the printer.
+
+	      <itemize>
+		<item>The <em/interrupt-driven/ method is the default
+		  with the GENERIC kernel.  With this method, the
+		  operating system uses an IRQ line to determine when
+		  the printer's ready for data.
+
+		<item>The <em/polled/ method directs the operating
+		  system to repeatedly ask the printer if it's ready
+		  for more data.  When it responds ready, the kernel
+		  sends more data.
+	      </itemize>
+
+	      The interrupt-driven method is somewhat faster but uses
+	      up a precious IRQ line.  You should use whichever one
+	      works.
+
+	      You can set the communications mode in two ways: by
+	      configuring the kernel or by using the <tt/lptcontrol/
+	      program.
+
+	      <bf>To set the communications mode by configuring the
+		kernel:</bf>
+	      <enum>
+		<item>Edit your kernel configuration file.  Look for
+		  or add an <tt/lpt0/ entry.  If you're setting up the
+		  second parallel port, use <tt/lpt1/ instead.  Use
+		  <tt/lpt2/ for the third port, and so on.
+		  <itemize>
+		    <item>If you want interrupt-driven mode, add the <tt/irq/
+		      specifer:
+<tscreen>
+<tt>device lpt0 at isa? port? tty irq <it/N/ vector lptintr</tt>
+</tscreen>
+		      where <it/N/ is the IRQ number for your
+		      computer's parallel port.
+
+		    <item>If you want polled mode, don't add the
+		      <tt/irq/ specifier:
+<tscreen>
+<tt>device lpt0 at isa? port? tty vector lptintr</tt>		
+</tscreen>
+		  </itemize>
+		<item>Save the file.  Then configure, build, and
+		  install the kernel, then reboot.  See <ref id="printing:kernel"
+		  name="kernel configuration"> for more details.
+	      </enum>
+
+	      <bf>To set the communications mode with
+		<tt/lptcontrol/:</bf>
+	      <itemize>
+		<item>
+		  Type
+<tscreen>
+<tt>lptcontrol -i -u <it/N/</tt>
+</tscreen>
+		  to set interrupt-driven mode for <tt/lpt<it/N//.
+
+		<item>
+		  Type
+<tscreen>
+<tt>lptcontrol -p -u <it/N/</tt>
+</tscreen>
+		  to set polled-mode for <tt/lpt<it/N//.
+	      </itemize>
+	      You could put these commands in your
+	      <tt>/etc/rc.local</tt> file to set the mode each time
+	      your system boots.  See lptcontrol(8) for more
+	      information.
+
+	  <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's a lot
+	      easier to debug printer communication and the spooling
+	      system separately.
+
+	      To test the printer, we'll send some text to it.  For
+	      printers that can immediately print characters sent to
+	      them, the program <tt/lptest/ is perfect: it generates
+	      all 96 printable ASCII characters in 96 lines.
+
+	      For a PostScript (or other language-based) printer,
+	      we'll need a more sophisticated test.  A small
+	      PostScript program, such as the following, will suffice:
+<code>
+%!PS
+100 100 moveto 300 300 lineto stroke
+310 310 moveto
+/Helvetica findfont 12 scalefont setfont
+(Is this thing working?) show
+showpage
+</code>
+	      <em/Note:/ When this document refers to a printer
+	      language, I'm assuming a language like PostScript, and
+	      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's the kind of printer language for
+	      which we must make special accomodations.
+
+	    <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.
+
+		<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 can't edit a line once
+			you've pressed RETURN or ENTER. When you've
+			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.  Don't worry if the
+		text doesn't look right; we'll 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&num;<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's 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 doesn't 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>&tilde;&gt;<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.  Don't worry if the
+		text doesn't look right; we'll 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've been able to send some simple data to the
+	    printer.  Now, we're 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's 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, can't directly print plain text.  The simple
+	    setup outlined above and described in the following
+	    sections assumes that if you're installing such a printer
+	    you'll 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're installing such a printer and
+	    want to be able to print jobs in the printer language
+	    <em/and/ print plain text jobs, you're 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="Accomodating
+	    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 doesn't 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
+	      don't 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's common practice to make the last alias for a
+	      printer be a full description of the printer, including
+	      make and model.
+
+	      Once you've 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's 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'll
+	      suppress header pages.
+
+	      To suppress header pages, add the <tt/sh/ capability to
+	      the entry for the printer in
+	      <tt>/etc/printcap</tt>. Here's 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're printed, and where a number of
+	      other spooler support files live.
+
+	      Because of the variable nature of spooling directories,
+	      it's customary to put these directories under
+	      <tt>/var/spool</tt>.  It's not necessary to backup the
+	      contents of spooling directories, either.  Recreating
+	      them is as simple as running <tt/mkdir/.
+
+	      It's also customary to make the directory with a name
+	      that's 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'll 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're concerned about the privacy of jobs
+	      that users print, you might want to protect the spooling
+	      directory so it's 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'll 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 don't 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's 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 don't 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 doesn't exist in FreeBSD.
+
+	      If the printer you're 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 don't 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&num;<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&num;<it/clear-bits/</tt>/
+
+		  Clears the flag bits <it/clear-bits/ in the
+		  <tt/sgttyb/ structure after opening the device.
+
+		<tag/<tt>fs&num;<it/set-bits/</tt>/
+
+		  Sets the flag bits <it/set-bits/ in the <tt/sgttyb/
+		  structure.
+
+		<tag/<tt>xc&num;<it/clear-bits/</tt>/
+
+		  Clears local mode bits <it/clear-bits/ after opening
+		  the device.
+
+		<tag/<tt>xs&num;<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> and also BLAH
+	      (the serial communications document).
+
+	      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's add to our example printer on the sixth serial
+	      port.  We'll set the bps rate to 38400. For the flag
+	      bits, we'll set the TANDEM, ANYP, LITOUT, FLUSHO, and
+	      PASS8 flags.  For the local mode bits, we'll 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're 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, peform 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's 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 &ero;&ero; 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'll 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've reached the end of the simple LPD setup.
+	      Unfortunately, congratulations are not quite yet in
+	      order, since we've still got 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're 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're using <tt/lptest/, then your
+	      results should look like the following:
+
+<tscreen><verb>
+!"#$%&ero;'()*+,-./01234
+"#$%&ero;'()*+,-./012345
+#$%&ero;'()*+,-./0123456
+$%&ero;'()*+,-./01234567
+%&ero;'()*+,-./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 didn't 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've gotten one of the following results instead of
+	      the correct printout:
+	      <descrip>
+		<tag/It worked, after awhile; or, it didn't eject a full sheet./
+
+		  The printer printed the above, but it sat for awhile
+		  and did nothing.  In fact, you might've 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's also useful to make sure each
+		  print job ends on a full sheet, so the next job
+		  doesn't 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 &ero;&ero; printf "\f" &ero;&ero; exit 0
+exit 2
+</code>
+
+		<tag/It produced the ``staircase effect.''/
+
+		  You got the following on paper:
+<tscreen><verb>
+!"#$%&ero;'()*+,-./01234
+                        "#$%&ero;'()*+,-./012345
+                                                #$%&ero;'()*+,-./0123456
+                                                                        $%&ero;'()*+,-./01234567
+</verb></tscreen>
+		  You've 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's what
+		  the carriage return is for: to move the location of
+		  the next character to print to the left edge of the
+		  paper.
+
+		  Here's 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's 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&ero;k2G" &ero;&ero; cat &ero;&ero; printf "\f" &ero;&ero; exit 0
+exit 2
+</code>
+
+			Here's 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's
+			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 didn't print a few
+		  characters in each line.  The problem might've
+		  gotten worse as the printer ran, losing more and
+		  more characters.
+
+		  The problem is that the printer can't keep up with
+		  the speed at which the computer sends data over a
+		  serial line.  (This problem shouldn't 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 doesn't 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're debugging in the <tt>/etc/printcap</tt> file.
+		  For example, here's 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 don't 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've setup with
+	FreeBSD.  Here's 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's 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 don't
+	use the <tt/-P/ option, then these commands use the printer
+	specified in the PRINTER environment variable.  Finally, if
+	you don't 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's 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's
+	  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'll 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's 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's 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's 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're 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 doesn't
+	    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 can't
+	    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:/ Don't 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 indepdendent 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's 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/-&num; <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/ Don't copy the files to the spooling directory,
+		but make symbolic links to them instead.
+
+		If you're 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 won't 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 can't modify or
+		remove them until they have been printed.
+
+		<em/Note:/ If you're 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's 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're 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've 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 won't 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'll 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 aren't
+	      properly removed by LPD, particularly if there have been
+	      errors during printing or a lot of administrative
+	      activity.  This command finds files that don't 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're testing a new
+	      printer or filter installation: disable the queue and
+	      submit jobs as root.  Other users won't be able to
+	      submit jobs until you complete your testing and reenable
+	      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 won't print anything until it's 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
+	      can't 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 won't 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 can't 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 don't 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're not, they're 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's about all it does.)  There are also
+	  several filters and filter components in the FreeBSD ports
+	  collection.
+
+	  Here's what you'll 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's 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 can't directly
+	      print plain text.  Section <ref
+	      id="printing:advanced:if-conversion" name="Accomodating
+	      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 don't 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're 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's 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's the text filter's job
+		to make sure backspaces, tabs, or other special
+		characters don't confuse the printer.
+
+		If you're 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 can't 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's 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 doesn't
+		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're shopping for filters, see if they're
+	    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're 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 don't 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're 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/&percnt;!/ (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 aren't 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've 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/ should be part of the FreeBSD ports collection
+	    (see <ref id="ports" name="The Ports Collection">); if not,
+	    it should be shortly.  You can fetch, build and install it
+	    yourself, of course.  After installing <tt/lprps/, just
+	    specify the pathname to the <tt/psif/ program that's 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 parralel PostScript printer (and therefore
+	    can't 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 &ero;&ero; cat &ero;&ero; printf "\004" &ero;&ero; exit 0
+   exit 2
+else
+   #
+   #  Plain text, convert it, then print it.
+   #
+   ( echo $first_line; cat ) | /usr/local/bin/textps &ero;&ero; printf "\004" &ero;&ero; 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 workalike 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'd 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's printing a PostScript file.  If it's 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's 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&ero;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's PostScript; use Ghostscript to scan-convert and print it
+    #
+    /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 -sOutputFile=- - \
+        &ero;&ero; 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 &ero;&ero; cat &ero;&ero; printf "\f" &ero;&ero; 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's 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'll 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 can't 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're 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've 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'd 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 they're specialized programs that only LPD will
+	      run; regular users shouldn't 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'll add the DVI conversion filter to
+	      the entry for the printer named <tt/bamboo/.  Here's 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's that script:
+<code>
+#!bin/sh
+#
+#  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="Accomodating 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's 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:$PATH; export PATH
+
+giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \
+    && exit 0 \
+    || exit 2
+</code>
+	      It works by converting the GIF file into a portable
+	      anymap, converting that into a portable graymap,
+	      converting that into a portable bitmap, and converting
+	      that into LaserJet/PCL-compatible data.
+
+	      Here's the <tt>/etc/printcap</tt> file with an entry for
+	      a printer using the above filter:
+<code>
+#
+#  /etc/printcap for host orchid
+#
+teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\
+	:lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\
+	:if=/usr/local/libexec/hpif:\
+	:vf=/usr/local/libexec/hpvf:
+</code>
+
+	      The following script is a conversion filter for troff
+	      data from the groff typesetting system for the
+	      PostScript printer named <tt/bamboo/:
+<code>
+#!/bin/sh
+#
+#  pstf - Convert groff's troff data into PS, then print.
+#  Installed in /usr/local/libexec/pstf
+#
+exec grops | /usr/local/libexec/lprps "$@"
+</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'd 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's it.  Here's 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's an example that might make old hands at FORTRAN
+              blush.  It's a FORTRAN-text filter for any printer that
+	      can directly print plain text.  We'll 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&ero;k2G" &ero;&ero; fpr &ero;&ero; printf "\f" &ero;&ero; exit 0
+exit 2
+</code>
+	      And we'll 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's one final, somewhat complex example.  We'll 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/ can't read from standard input.  It
+	      wants to work with a filename.  What's 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
+	      can't 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 won't 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's
+	      (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$$.dvi
+}
+
+#
+#  Define a function to handle fatal errors: print the given message
+#  and exit 2.  Exiting with 2 tells LPD to don't try to reprint the
+#  job.
+#
+fatal() {
+    echo "$@" 1>&ero;2
+    cleanup
+    exit 2
+}
+
+#
+#  If user removes the job, LPD will send SIGINT, so trap SIGINT
+#  (and a few other signals) to clean up after ourselves.
+#
+trap cleanup 1 2 15 
+
+#
+#  Make sure we're not colliding with any existing files.
+#
+cleanup
+
+#
+#  Link the DVI input file to standard input (the file to print).
+#
+ln -s /dev/fd/0 hpdf$$.dvi || fatal "Cannot symlink /dev/fd/0"
+
+#
+#  Make LF = CR+LF
+#
+printf "\033&ero;k2G" || fatal "Cannot initialize printer"
+
+# 
+#  Convert and print.  Return value from dvilj2p doesn't 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 aren't particularly computer
+	      literate, having to specify a filter option will become
+	      annoying.  What's 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's the
+	      default filter) detect the type of file it's asked to
+	      print and then automatically run the right conversion
+	      filter.  Tools such as <tt/file/ can be of help here.
+	      Of course, it'll 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've 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're 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 doesn't make any provision to identify the
+		start or the end of files within the job for the
+		output filter.
+
+	      <item>LPD doesn't pass the user's login or host to
+		the filter, so it's 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>
+
+	    Don't be seduced by an output filter's simplicity.  If
+	    you'd like each file in a job to start on a different page
+	    an output filter <em/won't 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's also <em/futile/ if you want to charge
+	    header pages to the requesting user's account, since LPD
+	    doesn't 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'll
+	    restart the output filter by sending SIGCONT to it.
+
+	    If there's 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/, whch we introduced earlier as a text
+	    filter, can also run as an output filter.  If you need a
+	    quick-and-dirty output filter but don't 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
+	    intialization 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's 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've got <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're printed.  They're
+	  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's 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've got a PostScript printer, you'll 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're right.  You <em/might/ have to provide an output
+	    filter to send initialization strings to the printer.
+	    Here's 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&ero;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's 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's 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've got <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 isn't provided with any
+	    <em/user or host/ information or an accounting file, so it
+	    has no idea whom to charge for printer use.  It's 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 didn't print.  Basically, <tt/lpr -h/ will be the
+	    preferred option of environmentally-minded users, but you
+	    can't offer any incentive to use it.
+
+	    It's <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 isn't meant to do anything more than
+		initialize a printer or do some simple character
+		conversion.  It's suited for header pages and plain
+		text jobs (when there's 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 doesn't know what accounting file to use
+		(it's 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
+	    can't 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's 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're using:
+#
+page_width=612
+page_height=792
+border=72
+
+#
+#  Check arguments
+#
+if [ $# -ne 3 ]; then
+    echo "Usage: `basename $0` <user> <host> <job>" 1>&ero;2
+    exit 1
+fi
+
+#
+#  Save these, mostly for readability in the PostScript, below.
+#
+user=$1
+host=$2
+job=$3
+date=`date`
+
+#
+#  Send the PostScript code to stdout.
+#
+exec cat <<EOF
+%!PS
+
+%
+%  Make sure we don't interfere with user's job that will follow
+%
+save
+
+%
+%  Make a thick, unpleasant border around the edge of the paper.
+%
+$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) ($date) ] {
+	270 y moveto show /y y 18 sub def
+} forall
+
+%
+%  That's it
+%
+restore
+showpage
+EOF
+</code>
+	    Now, each of the conversion filters and the text filter
+	    can call this script to first generate the header page,
+	    and then print the user's job.  Here's the DVI conversion
+	    filter from earlier in this document, modified to make a
+	    header page:
+<code>
+#!/bin/sh
+#
+#  DVI to PostScript printer filter
+#  Installed in /usr/local/libexec/psdf
+#
+#  Invoked by lpd when user runs lpr -d
+#
+
+orig_args="$@"
+
+fail() {
+    echo "$@" 1>&ero;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 $0` wrong." 1>&ero;2
+              exit 2
+              ;;
+    esac
+done
+
+[ "$login" ] || fail "No login name"
+[ "$host" ] || fail "No host name"
+
+( /u/kelly/freebsd/printing/filters/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've 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 wouldn't 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'll 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 won't 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've got 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/ doesn't 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've enabled.
+
+	    If you're using a printer with a network interface that's
+	    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's it.  You don't need to list conversion filters,
+	    page dimensions, or anything else in the
+	    <tt>/etc/printcap</tt> file.
+
+	    Here's an example.  The host rose has two printers,
+	    <tt/bamboo/ and <tt/rattan/.  We'll enable users on the
+	    host orchid to print to those printers.  Here's 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've 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's 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
+	    version, 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're using a serial interface), what baud rate, whether
+	    to use flow control, delays for tabs, conversion of
+	    newlines, and more.  But there's no way to specify a
+	    connection to a printer that's 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's 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', &ero;AF_INET, $printer_port, $address);
+
+socket(PRINTER, &ero;PF_INET, &ero;SOCK_STREAM, $protocol)
+    || die "Can't create TCP/IP stream socket: $!";
+connect(PRINTER, $sockaddr) || die "Can't contact $printer_host: $!";
+while (<STDIN>) { print PRINTER; }
+exit 0;
+</code>
+	    We can then use this script in various filters.  Suppose
+	    we had a Diablo 750-N line printer connected to the
+	    network.  The printer accepts data to print on port number
+	    5100.  The host name of the printer is scrivener.  Here's
+	    the text filter for the printer:
+<code>
+#!/bin/sh
+#
+#  diablo-if-net - Text filter for Diablo printer `scrivener' listening
+#  on port 5100.  Installed in /usr/local/libexec/diablo-if-net
+#
+
+exec /usr/libexec/lpr/lpf "$@" | /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 -&num;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/-&num;/ option
+	    to <tt/lpr/ by adding the <tt/sc/ capability to the
+	    <tt>/etc/printcap</tt> file.  When users submit jobs
+	    with the <tt/-&num;/ option, they'll see
+<tscreen><verb>
+lpr: multiple copies are not allowed
+</verb></tscreen>
+
+	    Note that if you've 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's an example.  This is the <tt>/etc/printcap</tt>
+	    file for the host rose.  The printer <tt/rattan/ is quite
+	    hearty, so we'll allow multiple copies, but the laser
+	    printer <tt/bamboo/'s a bit more delicate, so we'll
+	    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're at
+	    it, let's 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 -&num;/, but that still doesn't prevent users from
+	    running <tt/lpr/ multiple times, or from submitting the
+	    same file mutliple 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's appropriate (see
+	    section <ref name="Printers Installed on Remote Hosts"
+	    id="printing:advanced:network:rm">).
+
+	    For example, we'll let anyone access the printer
+	    <tt/rattan/, but only those in group <tt/artists/ can use
+	    <tt/bamboo/.  Here's 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's 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's only
+	    so much free space on the filesystem that houses the
+	    spooling directories, and you also need to make sure
+	    there's 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'll 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 won't refuse a file that's larger than the limit you
+	    place on a printer.  Instead, it'll 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's add limits to our example printers <tt/rattan/ and
+	    <tt/bamboo/.  Since those artists' PostScript files tend
+	    to be large, we'll limit them to five megabytes.  We'll
+	    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've set up access to your printers remotely, remote
+	    users won't get those limits.  You'll 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's 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's 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 won't fill your
+		filesystem.  You can also use it to give a certain
+		priority to local users: they'll 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's 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's <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'll 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'd 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've 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 doesn't
+	  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 can't 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's 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's 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're 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'll 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's 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're 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/
+		capabilty 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 doesn't 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
+	    hundreths 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 hundreths 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.  Don't
+	    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're 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's 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've been reading straight through this manual, by now
+	you've 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've located only <em/two/ alternatives---and
+	they're 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's also a <htmlurl
+	      url="http://www.iona.ie:8000/www/hyplan/jmason/plp.html"
+	      name="web page">.
+
+	    It's 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'd like to thank the following people who've assisted in
+	the development of this document:
+
+	<descrip>
+	  <tag/Daniel Eischen <tt/&lt;deischen@iworks.interworks.org&gt;//
+
+	    For providing a plethora of HP filter programs for perusal.
+
+	  <tag/Jake Hamby <tt/&lt;jehamby@lightside.com&gt;//
+
+	    For the Ghostscript-to-HP filter.
+
+	  <tag/My wife, Mary Kelly <tt/&lt;urquhart@argyre.colorado.edu&gt;//
+
+	    For allowing me to spend more time with FreeBSD than with her.
+
+	</descrip>
diff --git a/share/doc/handbook/sections.sgml b/share/doc/handbook/sections.sgml
index 66c25a3..1312598 100644
--- a/share/doc/handbook/sections.sgml
+++ b/share/doc/handbook/sections.sgml
@@ -1,4 +1,4 @@
-<!-- $Id: sections.sgml,v 1.2 1995/09/25 04:53:33 jfieber Exp $ -->
+<!-- $Id: sections.sgml,v 1.3 1995/09/25 18:23:04 wollman Exp $ -->
 <!-- The FreeBSD Documentation Project -->
 
 <!-- Entities containing all the pieces of the handbook are -->
@@ -30,6 +30,7 @@
 <!ENTITY porting SYSTEM "porting.sgml">
 <!ENTITY ports SYSTEM "ports.sgml">
 <!ENTITY ppp SYSTEM "ppp.sgml">
+<!ENTITY printing SYSTEM "printing.sgml">
 <!ENTITY relnotes SYSTEM "relnotes.sgml">
 <!ENTITY scsi SYSTEM "scsi.sgml">
 <!ENTITY skey SYSTEM "skey.sgml">