printing-advanced.html

FreeBSD操作系统的详细使用手册

#  These are PostScript units (72 to the inch).  Modify for A4 or
#  whatever size paper you are using:
#
page_width=612
page_height=792
border=72

#
#  Check arguments
#
if [ $# -ne 3 ]; then
    echo "Usage: `basename $0` <user> <host> <job>" 1>&2
    exit 1
fi

#
#  Save these, mostly for readability in the PostScript, below.
#
user=$1
host=$2
job=$3
date=`date`

#
#  Send the PostScript code to stdout.
#
exec cat <<EOF
%!PS

%
%  Make sure we do not interfere with user's job that will follow
%
save

%
%  Make a thick, unpleasant border around the edge of the paper.
%
$border $border moveto
$page_width $border 2 mul sub 0 rlineto
0 $page_height $border 2 mul sub rlineto
currentscreen 3 -1 roll pop 100 3 1 roll setscreen
$border 2 mul $page_width sub 0 rlineto closepath
0.8 setgray 10 setlinewidth stroke 0 setgray

%
%  Display user's login name, nice and large and prominent
%
/Helvetica-Bold findfont 64 scalefont setfont
$page_width ($user) stringwidth pop sub 2 div $page_height 200 sub moveto
($user) show

%
%  Now show the boring particulars
%
/Helvetica findfont 14 scalefont setfont
/y 200 def
[ (Job:) (Host:) (Date:) ] {
200 y moveto show /y y 18 sub def }
forall

/Helvetica-Bold findfont 14 scalefont setfont
/y 200 def
[ ($job) ($host) ($date) ] {
        270 y moveto show /y y 18 sub def
} forall

%
% That is it
%
restore
showpage
EOF
</pre>

<p>Now, each of the conversion filters and the text filter can call this script to first
generate the header page, and then print the user's job. Here is the DVI conversion
filter from earlier in this document, modified to make a header page:</p>

<pre class="PROGRAMLISTING">
#!/bin/sh
#
#  psdf - DVI to PostScript printer filter
#  Installed in /usr/local/libexec/psdf
#
#  Invoked by lpd when user runs lpr -d
#
                
orig_args="$@"

fail() {
    echo "$@" 1&gt;&amp;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&gt;&amp;2
              exit 2
              ;;
    esac
done

[ "$login" ] || fail "No login name"
[ "$host" ] || fail "No host name"

( /usr/local/libexec/make-ps-header $login $host "DVI File"
  /usr/local/bin/dvips -f ) | eval /usr/local/libexec/lprps $orig_args
</pre>

<p>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 <a
href="printing-advanced.html#PRINTING-ADVANCED-FILTERS">How Filters Work</a>).</p>

<p>As we have mentioned before, the above scheme, though fairly simple, disables the
``suppress header page'' option (the <var class="OPTION">-h</var> option) to <tt
class="COMMAND">lpr</tt>. If users wanted to save a tree (or a few pennies, if you charge
for header pages), they would not be able to do so, since every filter's going to print a
header page with every job.</p>

<p>To allow users to shut off header pages on a per-job basis, you will need to use the
trick introduced in section <a
href="printing-advanced.html#PRINTING-ADVANCED-HEADER-PAGES-ACCOUNTING">Accounting for
Header Pages</a>: write an output filter that parses the LPD-generated header page and
produces a <span class="TRADEMARK">PostScript</span> version. If the user submits the job
with <tt class="COMMAND">lpr -h</tt>, then <b class="APPLICATION">LPD</b> will not
generate a header page, and neither will your output filter. Otherwise, your output
filter will read the text from <b class="APPLICATION">LPD</b> and send the appropriate
header page <span class="TRADEMARK">PostScript</span> code to the printer.</p>

<p>If you have a <span class="TRADEMARK">PostScript</span> printer on a serial line, you
can make use of <tt class="COMMAND">lprps</tt>, which comes with an output filter, <tt
class="COMMAND">psof</tt>, which does the above. Note that <tt class="COMMAND">psof</tt>
does not charge for header pages.</p>
</div>
</div>

<div class="SECT2">
<h2 class="SECT2"><a id="PRINTING-ADVANCED-NETWORK-PRINTERS"
name="PRINTING-ADVANCED-NETWORK-PRINTERS">9.4.3 Networked Printing</a></h2>

<p>FreeBSD supports networked printing: sending jobs to remote printers. Networked
printing generally refers to two different things:</p>

<ul>
<li>
<p>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 <b
class="APPLICATION">LPD</b> to enable access to the printer from other hosts on the
network. Section <a href="printing-advanced.html#PRINTING-ADVANCED-NETWORK-RM">Printers
Installed on Remote Hosts</a> tells how to do this.</p>
</li>

<li>
<p>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:</p>

<ul>
<li>
<p>It might understand the <b class="APPLICATION">LPD</b> protocol and can even queue
jobs from remote hosts. In this case, it acts just like a regular host running <b
class="APPLICATION">LPD</b>. Follow the same procedure in section <a
href="printing-advanced.html#PRINTING-ADVANCED-NETWORK-RM">Printers Installed on Remote
Hosts</a> to set up such a printer.</p>
</li>

<li>
<p>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 <a
href="printing-advanced.html#PRINTING-ADVANCED-NETWORK-NET-IF">Printers with Networked
Data Stream Interfaces</a> gives some suggestions on installing such printers.</p>
</li>
</ul>
</li>
</ul>

<div class="SECT3">
<h3 class="SECT3"><a id="PRINTING-ADVANCED-NETWORK-RM"
name="PRINTING-ADVANCED-NETWORK-RM">9.4.3.1 Printers Installed on Remote Hosts</a></h3>

<p>The <b class="APPLICATION">LPD</b> spooling system has built-in support for sending
jobs to other hosts also running <b class="APPLICATION">LPD</b> (or are compatible with
<b class="APPLICATION">LPD</b>). 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 <b class="APPLICATION">LPD</b> protocol.</p>

<p>To enable this kind of remote printing, first install a printer on one host, the <span
class="emphasis"><i class="EMPHASIS">printer host</i></span>, using the simple printer
setup described in the <a href="printing-intro-setup.html#PRINTING-SIMPLE">Simple Printer
Setup</a> section. Do any advanced setup in <a href="printing-advanced.html">Advanced
Printer Setup</a> that you need. Make sure to test the printer and see if it works with
the features of <b class="APPLICATION">LPD</b> you have enabled. Also ensure that the
<span class="emphasis"><i class="EMPHASIS">local host</i></span> has authorization to use
the <b class="APPLICATION">LPD</b> service in the <span class="emphasis"><i
class="EMPHASIS">remote host</i></span> (see <a
href="printing-advanced.html#PRINTING-ADVANCED-RESTRICTING-REMOTE">Restricting Jobs from
Remote Printers</a>).</p>

<p>If you are using a printer with a network interface that is compatible with <b
class="APPLICATION">LPD</b>, then the <span class="emphasis"><i class="EMPHASIS">printer
host</i></span> in the discussion below is the printer itself, and the <span
class="emphasis"><i class="EMPHASIS">printer name</i></span> is the name you configured
for the printer. See the documentation that accompanied your printer and/or
printer-network interface.</p>

<div class="TIP">
<blockquote class="TIP">
<p><b>Tip:</b> If you are using a Hewlett Packard Laserjet then the printer name <var
class="LITERAL">text</var> will automatically perform the LF to CRLF conversion for you,
so you will not require the <tt class="FILENAME">hpif</tt> script.</p>
</blockquote>
</div>

<p>Then, on the other hosts you want to have access to the printer, make an entry in
their <tt class="FILENAME">/etc/printcap</tt> files with the following:</p>

<ol type="1">
<li>
<p>Name the entry anything you want. For simplicity, though, you probably want to use the
same name and aliases as on the printer host.</p>
</li>

<li>
<p>Leave the <var class="LITERAL">lp</var> capability blank, explicitly (<var
class="LITERAL">:lp=:</var>).</p>
</li>

<li>
<p>Make a spooling directory and specify its location in the <var
class="LITERAL">sd</var> capability. <b class="APPLICATION">LPD</b> will store jobs here
before they get sent to the printer host.</p>
</li>

<li>
<p>Place the name of the printer host in the <var class="LITERAL">rm</var>
capability.</p>
</li>

<li>
<p>Place the printer name on the <span class="emphasis"><i class="EMPHASIS">printer
host</i></span> in the <var class="LITERAL">rp</var> capability.</p>
</li>
</ol>

<p>That is it. You do not need to list conversion filters, page dimensions, or anything
else in the <tt class="FILENAME">/etc/printcap</tt> file.</p>

<p>Here is an example. The host <tt class="HOSTID">rose</tt> has two printers, <var
class="LITERAL">bamboo</var> and <var class="LITERAL">rattan</var>. We will enable users
on the host <tt class="HOSTID">orchid</tt> to print to those printers. Here is the <tt
class="FILENAME">/etc/printcap</tt> file for <tt class="HOSTID">orchid</tt> (back from
section <a href="printing-advanced.html#PRINTING-ADVANCED-HEADER-PAGES-ENABLING">Enabling
Header Pages</a>). It already had the entry for the printer <var
class="LITERAL">teak</var>; we have added entries for the two printers on the host <tt
class="HOSTID">rose</tt>:</p>

<pre class="PROGRAMLISTING">
#
#  /etc/printcap for host orchid - added (remote) printers on rose
#

#
#  teak is local; it is connected directly to orchid:
#
teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\
        :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\
        :if=/usr/local/libexec/ifhp:\
        :vf=/usr/local/libexec/vfhp:\
        :of=/usr/local/libexec/ofhp:

#
#  rattan is connected to rose; send jobs for rattan to rose:
#
rattan|line|diablo|lp|Diablo 630 Line Printer:\
        :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan:

#
#  bamboo is connected to rose as well:
#
bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\
        :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:
</pre>

<p>Then, we just need to make spooling directories on <tt class="HOSTID">orchid</tt>:</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">mkdir -p /var/spool/lpd/rattan /var/spool/lpd/bamboo</kbd>
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">chmod 770 /var/spool/lpd/rattan /var/spool/lpd/bamboo</kbd>
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">chown daemon:daemon /var/spool/lpd/rattan /var/spool/lpd/bamboo</kbd>
</pre>

<p>Now, users on <tt class="HOSTID">orchid</tt> can print to <var
class="LITERAL">rattan</var> and <var class="LITERAL">bamboo</var>. If, for example, a
user on <tt class="HOSTID">orchid</tt> typed</p>

<pre class="SCREEN">
<samp class="PROMPT">%</samp> <kbd
class="USERINPUT">lpr -P bamboo -d sushi-review.dvi</kbd>
</pre>

the <b class="APPLICATION">LPD</b> system on <tt class="HOSTID">orchid</tt> would copy
the job to the spooling directory <tt class="FILENAME">/var/spool/lpd/bamboo</tt> and
note that it was a DVI job. As soon as the host <tt class="HOSTID">rose</tt> has room in
its <var class="LITERAL">bamboo</var> spooling directory, the two <b
class="APPLICATION">LPDs</b> would transfer the file to <tt class="HOSTID">rose</tt>. The
file would wait in <tt class="HOSTID">rose</tt>'s queue until it was finally printed. It
would be converted from DVI to <span class="TRADEMARK">PostScript</span> (si