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<th colspan="3" align="center">LPRng Reference Manual: 24
Sep 2004 (For LPRng-3.8.28)</th>
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<td width="80%" align="center" valign="bottom">Chapter
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<h1 class="SECT1"><a name="BANNERPRINTING">15.6. Printing
Banners</a></h1>
<p>Options used:</p>
<ul>
<li>
<p><var class="LITERAL">ab</var> FLAG <span class=
"emphasis"><i class="EMPHASIS">Always print banner
(default FALSE)</i></span></p>
</li>
<li>
<p><var class="LITERAL">be=</var><span class=
"emphasis"><i class="EMPHASIS">End banner generator
program</i></span></p>
</li>
<li>
<p><var class="LITERAL">bl=</var><span class=
"emphasis"><i class="EMPHASIS">Short banner line
format</i></span></p>
</li>
<li>
<p><var class="LITERAL">bp=</var><span class=
"emphasis"><i class="EMPHASIS">Banner generator
program</i></span></p>
</li>
<li>
<p><var class="LITERAL">bs=</var><span class=
"emphasis"><i class="EMPHASIS">Start banner
generator</i></span></p>
</li>
<li>
<p><var class="LITERAL">generate_banner</var> FLAG <span
class="emphasis"><i class="EMPHASIS">Generate banner for
forwarded jobs</i></span></p>
</li>
<li>
<p><var class="LITERAL">hl</var> FLAG <span class=
"emphasis"><i class="EMPHASIS">Banner (header)
Last</i></span></p>
</li>
<li>
<p><var class="LITERAL">of=</var><span class=
"emphasis"><i class="EMPHASIS">Banner and File Separator
Filter</i></span></p>
</li>
<li>
<p><var class="LITERAL">sb</var> FLAG <span class=
"emphasis"><i class="EMPHASIS">Short banner (default
FALSE)</i></span></p>
</li>
<li>
<p><var class="LITERAL">sh</var> FLAG <span class=
"emphasis"><i class="EMPHASIS">Suppress header (banners)
(default FALSE)</i></span></p>
</li>
</ul>
<br>
<br>
<p>Banner printing is one of the more complicated
configuration options of <b class="APPLICATION">LPRng</b>.
This is due mainly to historical evolution of the software,
as well as a lack of a well defined standard for filter
responsibilities. In the original BSD print spoolers, the
philosophy was that banner printing should be delegated to
the filters, as they were the most aware of the capabilities
of the printers. This required an <span class="emphasis"><i
class="EMPHASIS">out of band</i></span> method to convey
banner printing information to the filter, and resulted in a
complicated interface. The original interface was:</p>
<ol type="1">
<li>
<p>The filter doing banner printing was invoked as a
special <var class="LITERAL">:of</var> filter, or passed
a special flag.</p>
</li>
<li>
<p>The print spooling software would send a special <span
class="emphasis"><i class="EMPHASIS">single
line</i></span> of information telling it what the banner
information should be. Note that this line was never
documented except for the source code, and was
inconsistent from version to version. Also, there was no
indication of what to do with additional lines, if
any.</p>
</li>
<li>
<p>The filter would generate the banner, discard the
line, and then pass other lines to the output device.</p>
</li>
</ol>
<br>
<br>
<p>Adding to the confusion, the original print spoolers had a
<var class="LITERAL">:sh</var> (suppress header or banner)
flag, which was supposed to suppress banner printing. It did
this by having the print spooler not generate the magic
banner information line.</p>
<p>A more sophisticated banner printing system would allow
the print spooler software to generate the banner, and would
then have the <var class="LITERAL">:of</var> filter act as a
pass through. Thus, we need configure the <var class=
"LITERAL">:of</var> filter NOT to use the first line as
banner printing information, and to pass through all
information to the device.</p>
<p>Complicating this whole mess is the <var class=
"LITERAL">ld</var> (leader option) and <var class=
"LITERAL">tr</var> (trailer option) which is a string sent to
the output device (<var class="LITERAL">:of</var> filter)
when the device (filter) is initialized or terminated. This
can sometimes be interpreted as the banner line, leading to
unexpected results.</p>
<p>Sequence of Operations:</p>
<ol type="1">
<li>
<p>If the <var class="LITERAL">sh</var> (suppress header)
flag is true, no banner is printed, and the actions in
this section are skipped. No <span class="emphasis"><i
class="EMPHASIS">banner information line</i></span> is
generated for the <var class="LITERAL">:of</var> filter,
and no banner printing program is invoked. If there is an
<var class="LITERAL">:of</var> filter and it is expecting
such a line and you have <var class="LITERAL">ld</var> or
<var class="LITERAL">tr</var> information then you may
get unexpected results (actually, catastrophic failure is
a better term, but I digress).</p>
</li>
<li>
<p>If the <var class="LITERAL">hl</var> (header last)
flag is true the banner is printed at the end of the job
and the actions in this section are done at the end of
the job.</p>
</li>
<li>
<p>If the user does not want banner pages she can use the
<tt class="COMMAND">lpr -h</tt> option. This will cause
the <b class="APPLICATION">lpr</b> program to delete the
<var class="LITERAL">L</var> (banner name) line in the
control file. If there is no <var class="LITERAL">L</var>
line in the control file and <var class=
"LITERAL">ab</var> (always print a banner) is false (the
default), then no banner is printed and the other actions
in this section are skipped. If <var class=
"LITERAL">ab</var> is true and the <var class=
"LITERAL">L</var> line is missing then the <var class=
"LITERAL">N</var> (user login name) is used; if it is
missing as well, then ANONYMOUS is used for the user
name.</p>
</li>
<li>
<p>If a banner printing program is specified by <var
class="LITERAL">bp</var>, <var class="LITERAL">bs</var>,
or <var class="LITERAL">be</var> options, then <b class=
"APPLICATION">LPRng</b> will invoke the program to
generate a banner and then send the generated banner to
the printer via the <var class="LITERAL">:of</var>
filter. The banner printing program will be invoked using
the standard filter command line flags (see <a href=
"filteroptions.htm">Filter Command Line Options and
Environment Variables</a> for details), with is <acronym
class="ACRONYM">STDIN</acronym> attached to /dev/null and
<acronym class="ACRONYM">STDOUT</acronym> attached to a
file to hold the output banner.</p>
</li>
<li>
<p>If no banner printing program is specified and the
<var class="LITERAL">sb</var> (short banner) option is
TRUE (default is true), then the <var class=
"LITERAL">bl=...</var> (banner line) option value is
expanded and sent to the <var class="LITERAL">of_fd</var>
(<var class="LITERAL">:of</var> filter or device. The
default <var class="LITERAL">bl</var> value is: <var
class="LITERAL">bl=$-'C:$-'n Job: $-'J Date: $-'t</var>.
Using our example, this will get translated to:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN7364"></a>
<pre class="SCREEN">
papowell:A Job: file1 file2 Date: Thu Nov 27 23:02:04 PST 1997
</pre>
</div>
<br>
<br>
</li>
<li>
<p>If no banner printing program is specified and we have
<var class="LITERAL">sb@</var> (no short banner) then we
skip banner generation, i.e. - we do <span class=
"emphasis"><i class="EMPHASIS">not</i></span> send a
banner generation line to the output (<var class=
"LITERAL">:of</var> filter).</p>
</li>
<li>
<p>If the queue is a normal forwarding queue, then the
<var class="LITERAL">generate_banner</var> option will
invoke the <var class="LITERAL">bp</var>, <var class=
"LITERAL">bs</var> or <var class="LITERAL">be</var>
program as appropriate to create a banner page file which
is then made the first (default) or last (<var class=
"LITERAL">hl</var> flag or <var class=
"LITERAL">be=...</var> present) file in a job. This
option has no effect in other types of queues. See the
<span class="emphasis"><i class="EMPHASIS"><a href=
"translateformat.htm">translate_format</a></i></span>
option as well.</p>
</li>
</ol>
<br>
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