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  The Linux Printing Usage HOWTO
  by Matt Foster  <[e-mail]>
  v1.0, 5 Aug 1995

  1.  Introduction

  This document describes how to use the line printer spooling system
  provided with the Linux operating system.  If you are looking for a
  guide to setting up your print environment, please see the Linux
  Printing Setup HOWTO.


  1.1.  Linux Printing HOWTO History

  This version of the Linux Printing HOWTO is a complete rewrite of the
  one originally written by Grant Taylor <[e-mail]> and Brian
  McCauley <[e-mail]>.  I have tried to keep with the
  coverage of material presented by Grant and Brian's HOWTO, but I have
  drastically modified the style of presentation and the depth of
  material covered.  I feel that this makes the HOWTO more complete and
  easier to read.  I can only hope that you agree.


  1.2.  Copyrights and Trademarks

  Some names mentioned in this HOWTO are claimed as copyrights and/or
  trademarks of certain persons and/or companies.  These names appear in
  full or initial caps in this HOWTO.


  The Linux Printing Usage HOWTO v1.0 (c) 1995 Matt Foster.


  Unless otherwise stated, Linux HOWTO documents are copyrighted by
  their respective authors. Linux HOWTO documents may be reproduced and
  distributed in whole or in part, in any medium physical or electronic,
  as long as this copyright notice is retained on all copies. Commercial
  redistribution is allowed and encouraged; however, the author would
  like to be notified of any such distributions.

  All translations, derivative works, or aggregate works incorporating
  any Linux HOWTO documents must be covered under this copyright notice.
  That is, you may not produce a derivative work from a HOWTO and impose
  additional restrictions on its distribution. Exceptions to these rules
  may be granted under certain conditions; please contact the Linux
  HOWTO coordinator at the address given below.

  In short, we wish to promote dissemination of this information through
  as many channels as possible. However, we do wish to retain copyright
  on the HOWTO documents, and would like to be notified of any plans to
  redistribute the HOWTOs.

  If you have questions, please contact Greg Hankins, the Linux HOWTO
  coordinator, at <[e-mail]>. You may finger this address
  for phone number and additional contact information.


  1.3.  Downloading the Linux Printing HOWTOs

  I recommend that if you want to print a copy of this HOWTO that you
  download the PostScript version.  It is formatted in a fashion that is
  aesthetically appealing and easier to read.  You can get the
  PostScript version from one of the many Linux distribution sites (such
  as SunSITE <ftp://sunsite.unc.edu/Linux/docs/HOWTO/>), or directly
  from my World Wide Web page at  <http://www.engr.uark.edu/~mwf/pht/>.

  1.4.  Feedback

  Questions, comments, or corrections for this HOWTO may be directed to
  <[e-mail]>.


  1.5.  Acknowledgments

  Thanks go out to all of the people who took the time to read the alpha
  version of this HOWTO and respond with many helpful comments and
  suggestions--some of you may see your comments reflected in the
  version.

  I would also like to thank Grant and Brian for the loads of
  information that they have given me during the transition of
  authorship.


  2.  Printing Under Linux

  This section discusses how to print files, examine the print queue,
  remove jobs from the print queue, format files before printing them,
  and configure your printing environment.


  2.1.  History

  The Linux printing system---the lp system---is a port of the source
  code written by the Regents of the University of California for the
  Berkeley Software Distribution version of the UNIX operating system.


  2.2.  Basic Printing

  By far, the most simplistic way to print in the Linux operating system
  is to send the file to be printed directly to the printing device.
  One way to do this is to use the cat command.  As the root user, one
  could do something like



       # cat thesis.txt > /dev/lp




  In this case, /dev/lp is a symbolic link to the actual printing
  device--be it a dot-matrix, laser printer, typesetter, or plotter.
  (See ln(1) for more information on symbolic links.)

  For the purpose of security, only the root user and users in the same
  group as the print daemon are able to write directly to the printer.
  This is why commands such as lpr, lprm, and lpq have to be used to
  access the printer.

  Because of this, users have to use lpr to print a file.  The lpr
  command is responsible for taking care of all of the initial work
  needed to print the file, and then it hands control over to another
  program, lpd, the line printing daemon.  The line printing daemon then
  tells the printer how to print the file.

  When lpr is executed, it first copies the specified file to a certain
  directory (the spool directory) where the file remains until lpd
  prints it.  Once lpd is told that there is a file to print, it will
  spawn a copy of itself (what we programmers call forking).  This copy
  will print our file while the original copy waits for more requests.
  This allows for multiple jobs to be queued at once.

  The syntax of lpr(1) is a very familiar one,



       $ lpr [ options ] [ filename ... ]




  If a filename is not specified, lpr assumes that the input should come
  from standard input (usually the keyboard, or another program's
  output).  This enables the user to redirect a command's output to the
  printing device.  As such,



       $ cat thesis.txt | lpr




  or, something more powerful, like



       $ pr -l60 thesis.txt | lpr




  The lpr command accepts several command-line arguments that allow a
  user to control how it works.  Some of the most widely used arguments
  are: -Pprinter specifies the printer to use, -h suppresses printing of
  the burst page, -s creates a symbolic link instead of copying the
  entire file to the spool directory (useful for large files), and -#num
  specifies the number of copies to print.  An example interaction with
  lpr might be something like



       $ lpr -#2 -sP dj thesis.txt




  This command would create a symbolic link to the file thesis.txt in
  the spool directory for the printer named dj, where it would be
  processed by lpd.  It would then print a second copy of thesis.txt.

  For a listing of all the options that lpr will recognize, see lpr(1).


  2.3.  Viewing the Print Queue

  Sometimes it is useful to know what jobs are currently in a particular
  printer's queue.  This is the sole task of the lpq command.

  To see what is in the queue of the default printer (as defined by
  /etc/printcap), use





  $ lpq
  lp is ready and printing
  Rank   Owner      Job  Files                            Total Size
  active mwf        31   thesis.txt                       682048 bytes





  2.4.  Canceling a Print Job

  Another useful feature of any printing system is the ability to cancel
  a job that has been previously queued.  To do this, use lprm.



       $ lprm -




  The above command cancels all of the print jobs that are owned by the
  user who issued the command.  A single print job can be canceled by
  first getting the job number as reported by lpq, and then giving that
  number to lprm.  For example,



       $ lprm 31




  would cancel job 31 (thesis.txt) on the default printer.


  3.  Miscellaneous Items

  This section discusses some of the miscellaneous things that you may
  want to know about printing under Linux.


  3.1.  Formatting

  Since most ASCII files are not formatted for printing, it is useful to
  format them in some way before they are actually printed.  This may
  include putting a title and page number on each page, setting the
  margins, double spacing, indenting, or printing a file in multiple
  columns.  A common way to do this is to use a print preprocessor such
  as pr.



       $ pr +4 -d -h"Ph.D. Thesis, 2nd Draft" -l60 thesis.txt | lpr




  In the above example, pr would take the file thesis.txt and skip the
  first three pages (+4), set the page length to sixty lines (-l60),
  double space the output (-d), and add the phrase "Ph.D. Thesis, 2nd
  Draft" to the top of each page (-h).  Lpr would then print pr's
  output.  See its on-line manual page for more information on using pr.



  3.2.  The PRINTER Environment Variables

  All of the commands in the Linux printing system accept the -P option.
  This option allows the user to specify which printer to use for
  output.  If a user doesn't specify which printer to use, then the
  default printer will be assumed as the output device.

  Instead of having to specify a printer to use every time that you
  print, you can set the PRINTER environment variable to the name of the
  printer that you want to use.  This is accomplished in different ways
  for each shell.  For bash you can do this with



       $ PRINTER="printer_name"; export PRINTER




  in csh, you can do it with



       % setenv PRINTER "printer_name"




  These commands can be placed in your login scripts (.profile or
  .cshrc), or issued on the command-line.  (See bash(1) and csh(1) for
  more information on environment variables.)


  3.3.  Printing PostScript files

  Printing PostScript files on a printer that has a PostScript
  interpreter is simple; just use lpr, and the printer will take care of
  all of the details for you.  For those of us that don't have printers
  with PostScript capabilities, we have to resort to other means.
  Luckily, there are programs available that can make sense of
  PostScript, and translate it into a language that most printers will
  understand.  Probably the most well known of these programs is
  Ghostscript.

  Ghostscript's responsibility is to convert all of the descriptions in
  a PostScript file to commands that the printer will understand.  To
  print a PostScript file using Ghostscript, you might do something like



       $ gs -dNOPAUSE -sDEVICE=deskjet -sOutputFile=|lpr thesis.ps




  Notice in the above example that we are actually piping the output of
  Ghostscript to the lpr command by using the -sOutputFile option.

  Ghostview is an interface to Ghostscript for the X Window System.  It
  allows you to preview a PostScript file before you print it.
  Ghostview and Ghostscript can both be downloaded from
  <ftp://prep.ai.mit.edu/pub/gnu/>.




  3.4.  Printing TeX files

  One of the easiest ways to print TeX files is to convert them to
  PostScript and then print them using Ghostscript.  To do this, you
  first need to convert them from TeX to a format known as DVI (which
  stands for device-independent).  You can do this with the tex(1)
  command.  Then you need to convert the DVI file to a PostScript file
  using dvips.  All of this would look like the following when typed in.



       $ tex thesis.tex
       $ dvips thesis.dvi




  Now you are ready to print the resulting PostScript file as described
  above.


  3.5.  Printing troff formatted files




       $ groff -Tascii thesis.tr | lpr




  or, if you prefer,



       $ groff thesis.tr > thesis.ps




  and then print the PostScript file as described above.


  4.  Answers to Frequently Asked Questions


  Q1.  How do I prevent the staircase effect?

  A1.  The staircase effect is caused by the way some printers expect
  lines to be terminated.  Some printers want lines that end with a
  carriage-return/line-feed sequence (DOS-style) instead of the default
  line-feed sequence used for UNIX-type systems.  The easiest way to fix
  this is to see if your printer can switch between the two styles
  somehow---either by flipping a DIP switch, or by sending an escape
  sequence at the start of each print job.  To do the latter, you need
  to create a filter (see Q2 and Foster95b).

  A quick fix is to use a filter on the command-line.  An example of
  this might be



       $ cat thesis.txt | todos | lpr



  Q2.  What is a filter?

  A2.  A filter is a program that reads from standard input (stdin),
  performs some action on this input, and writes to standard output
  (stdout).  Filters are used for a lot of things, including text
  processing.


  Q3.  What is a magic filter?

  A3.  A magic filter is a filter that performs an action based on a
  file's type.  For example, if the file is a plain, text file, it would
  simply print the file using the normal methods.  If the file is a
  PostScript file, or any other format, it would print it using another
  method (ghostscript).


  5.  Troubleshooting

  This section covers some common things that can go wrong with your
  printing system.  Send suggestions for this section to
  <[e-mail]>.


  6.  References

  This is a section of references on the Linux printing system.  I have
  tried to keep the references section of this HOWTO as focused as
  possible.  If you feel that I have forgotten a significant reference
  work, please do not hesitate to contact me.

  Before you post your question to a USENET group, consider the
  following:

  o  Is the printer accepting jobs?  (Use lpc(8) to verify.)

  o  Is the answer to your question covered in this HOWTO, or the
     Printing Setup HOWTO?

  If any of the above are true, you may want to think twice before you
  post your question.  And, when you do finally post to a newsgroup, try
  to include pertinent information.  Try not to just say something like,
  "I'm having trouble with lpr, please help."  These types of posts will
  most definitely be ignored by many.  Also try to include the kernel
  version that you're running, how the error occured, and, if any, the
  specific error message that the system returned.


     Welsh, Matt.  Linux Installation and Getting Started
        an excellent introductory text for the beginning Linux user


     Foster, Matt.  Linux Printing Setup HOWTO
        the supplement to this HOWTO; covers topics such as setting up,
        and configuring the print software


     On-Line Manual Pages

     o  cat(1)  concatenate and print files

     o  dvips(1)  convert a TeX DVI file to PostScript

     o  ghostview(1)  view PostScript documents using Ghostscript


     o  groff(1)  front-end for the groff document formatting system

     o  gs(1)  Ghostscript interpreter/viewer

     o  lpc(8)  line printer control program

     o  lpd(8)  line printer spooler daemon

     o  lpq(1)  spool queue examination program

     o  lpr(1)  off-line printer

     o  lprm(1)  remove jobs from the line printer spooling queue

     o  pr(1)  convert text files for printing

     o  tex(1)  text formatting and typesetting


     USENET newsgroups

     o  comp.os.linux.*  a plethora of information on Linux

     o  comp.unix.*  discussions relating to the UNIX operating system


  7.  Colophon

  This HOWTO was written using vi, the ultimate editor; the human mind,
  the ultimate computer; and imagination, the ultimate power tool.  The
  computer of choice was a Gateway2000 i486/50 running the Slackware 2.2
  distribution of Linux with version 1.3.4 of the kernel.  The original
  document was written in mark-up format using Linuxdoc-SGML (a hacked
  version of Tom Gordon's QWERTZ DTD).  The HOWTO was then emailed to
  Greg Hankins, the Linux Documentation Project coordinator.  There it
  was converted to PostScript, TeXinfo, DVI, ASCII, and HTML formats.
  Finally it was posted on USENET, and placed in the Linux archives
  found on the SunSITE FTP/WWW servers for easy Internet access.