<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta name="generator" content="HTML Tidy, see www.w3.org">
<title>Using Programs To Get Printcap Information</title>
<meta name="GENERATOR" content=
"Modular DocBook HTML Stylesheet Version 1.71 ">
<link rel="HOME" title=" LPRng-HOWTO" href="index.htm">
<link rel="UP" title="Printcap Database " href=
"printcapref.htm">
<link rel="PREVIOUS" title=
"Management Strategies for Large Installations" href=
"x6063.htm">
<link rel="NEXT" title="Lexmark Printers" href="x6173.htm">
</head>
<body class="SECT1" bgcolor="#FFFFFF" text="#000000" link=
"#0000FF" vlink="#840084" alink="#0000FF">
<div class="NAVHEADER">
<table summary="Header navigation table" width="100%" border=
"0" cellpadding="0" cellspacing="0">
<tr>
<th colspan="3" align="center">LPRng-HOWTO: 8 Feb 2002
(For LPRng-3.8.6)</th>
</tr>
<tr>
<td width="10%" align="left" valign="bottom"><a href=
"x6063.htm" accesskey="P">Prev</a></td>
<td width="80%" align="center" valign="bottom">Chapter
12. Printcap Database</td>
<td width="10%" align="right" valign="bottom"><a href=
"x6173.htm" accesskey="N">Next</a></td>
</tr>
</table>
<hr align="LEFT" width="100%">
</div>
<div class="SECT1">
<h1 class="SECT1"><a name="SECNIS">12.18. Using Programs To
Get Printcap Information</a></h1>
<p>In the <tt class="FILENAME">lpd.conf</tt> file you can
specify:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6075"></a>
<pre class="SCREEN">
printcap_path=|program
</pre>
</div>
This will cause the <b class="APPLICATION">LPRng</b> software
to execute the specified program, which should then provide
the printcap information. The program is invoked with the
standard filter options, and has the name of the printcap
entry provided on <span class="ACRONYM">STDIN</span>. The
filter should supply the printcap information on <tt class=
"LITERAL">stdout</tt> and exit with a 0 (success) error code.
By convention, the printcap name 'all' requests a printcap
entry that lists all printers.<br>
<br>
<p>This technique has been used to interface to the Sun
Microsystem NIS and NIS+ databases with great success. By
having the invoked program a simple shell script or front end
to the <tt class="LITERAL">nismatch</tt> or <tt class=
"LITERAL">ypmatch</tt> programs, the complexity of
incorporating vendor specific code is avoided.</p>
<div class="SECT2">
<h2 class="SECT2"><a name="AEN6083">12.18.1. How to use NIS
and <b class="APPLICATION">LPRng</b></a></h2>
<p>This note is based on material sent to the <a href=
"maillist.htm">lprng@lprng.com</a> mailing list by Paul
Haldane <tt class="EMAIL"><<a href=
"mailto:paul@ucs.ed.ac.uk">paul@ucs.ed.ac.uk</a>></tt>.</p>
<p>We generally don't use NIS for printcap files (we've
moved to hesiod) but I can show you what we've done in the
past.</p>
<p>The input to NIS is a normal printcap file:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6091"></a>
<pre class="SCREEN">
# Classical printcap entry
lp23a|lp23|lp|main printhost printer - KB, EUCS front Door:\
:lp=lp23a@printhost:\
:sd=/var/spool/lpr/lp23a:
#lprng printcap entry
lplabel|lpl|TEST - Labels printer:
:lp=:rm=printhost:rp=lplabel:
:sd=/var/spool/lpr/lplabel:
:rg=lpadm:mx=1:
</pre>
</div>
<br>
<br>
<p>To build the NIS printcap.byname map we add the
following to the NIS makefile (along the other bits and
pieces that the makefile needs to know about a new
map).</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6094"></a>
<pre class="SCREEN">
PRINTCAP=${sysconfdir}/printcap
# warning : [ ] is actually [<space><tab>] in the script
printcap.time: $(PRINTCAP) Makefile
if [ -f $(PRINTCAP) ]; then \
sed < $(PRINTCAP) \
-e 's/[ ][ ]*$$//' -e '/\\$$/s/\\$$/ /' \
| awk '$$1 ~ /^#/{next;} $$1 ~ /^[:|]/ {printf "%s", $$0; next;} \
{printf "\n%s", $$0 }' \
| sed -e 's/[ ]*:[ ]*:/:/g' -e 's/[ ]*|[ ]*/|/g' \
-e '/^[ ]*$$/d' > .printcap.$$$$; \
cat .printcap.$$$$; \
if [ $$? = 0 -a -s .printcap.$$$$ ]; then \
awk <.printcap.$$$$ '{ FS=":"; OFS="\t"; } { \
n = split($$1, names, "|"); \
for (i=1; i<=n; i++) \
if (length(names[i]) > 0 \
&& names[i] !~ /[ \t]/) \
print names[i], $$0; \
}' | $(MAKEDBM) - $(YPDBDIR)/$(DOM)/printcap.byname; \
awk <.printcap.$$$$ '{ FS=":"; OFS="\t"; } { \
n = split($$1, names, "|"); \
if (n && length(names[1]) > 0 && names[1] !~ /[ \t]/) \
print names[1], $$0; \
}' | $(MAKEDBM) - $(YPDBDIR)/$(DOM)/printcap.bykey; \
rm -f .printcap.$$$$; \
touch printcap.time; echo "updated printcap"; \
fi \
fi
@if [ ! $(NOPUSH) -a -f $(PRINTCAP) ]; then \
$(YPPUSH) printcap.byname; \
$(YPPUSH) printcap.bykey; \
touch printcap.time; echo "pushed printcap"; \
fi
</pre>
</div>
<br>
<br>
<p>To specify that you want YP database rather than file
access, use the following entry in your <tt class=
"FILENAME">/etc/lpd.conf</tt> file:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6098"></a>
<pre class="SCREEN">
printcap_path |/usr/local/libexec/pcfilter
</pre>
</div>
<br>
<br>
<p>Put the following shell script in
/usr/local/libexec/pcfilter</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6101"></a>
<pre class="SCREEN">
#!/bin/sh
#/usr/local/libexec/filters/pcfilter
read key
# specify the full pathname to the ypmatch program
# the location depends on the version of Solaris or your
# system install
/full/pathname/to/ypmatch "$key" printcap.byname
</pre>
</div>
<br>
<br>
<p>You can test this by using:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6104"></a>
<pre class="SCREEN">
<tt class="PROMPT">h4: {314} #</tt> <tt class=
"USERINPUT"><b>lpc client pr</b></tt>
pr
:lp=pr@server
<tt class="PROMPT">h4: {315} #</tt> <tt class=
"USERINPUT"><b>lpc server pr</b></tt>
pr
:lp=pr@server
</pre>
</div>
<br>
<br>
</div>
<div class="SECT2">
<h2 class="SECT2"><a name="AEN6110">12.18.2. How to use NIS
and <b class="APPLICATION">LPRng</b> - Sven
Rudolph</a></h2>
<div class="INFORMALEXAMPLE">
<a name="AEN6114"></a>
<pre class="SCREEN">
Date: Wed, 11 Sep 1996 00:11:02 +0200
From: Sven Rudolph <sr1@os.inf.tu-dresden.de>
To: lprng@lprng.com
Subject: Using :oh=server: with NIS
</pre>
</div>
<br>
<br>
<p>When I use a cluster-wide printcap, I want the entries
for each printer to appear, e.g.:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6117"></a>
<pre class="SCREEN">
---------- start of printcap snippet
lp1
:lp=lp1@server
lp2
:lp=lp2@server
lp1
:server:oh=servername
:sd=/var/spool/lpd/lp1
:lp=/dev/lp1
:mx=0
---------- end of printcap snippet
</pre>
</div>
<br>
<br>
<p>When I create a NIS map out of this the printer name is
used as a key and must be unique. The NIS makedbm will drop
all but the last entry for each printer. This makes the
printer on the clients unavailable. I solved this by a hack
where the second entry is called lp1.server and the NIS
client script has to request the right entry.</p>
<ol type="1">
<li>
<p>Assumptions</p>
<p>Perl is available at the YP server in <tt class=
"COMMAND">/usr/bin/perl</tt>. A Bourne Shell is
available at all clients in <tt class=
"COMMAND">/bin/sh</tt> The printcap that is to be
exported is in <tt class="FILENAME">/etc/printcap</tt>.
The printcap is written in the new format. In the
examples the printer is called lp1.</p>
</li>
<li>
<p>Add the following to your YP <tt class=
"FILENAME">Makefile</tt> (<tt class=
"FILENAME">/var/yp/Makefile</tt>) on the YP server
(these lines are for Debian GNU/Linux, other systems
might require other modifications):</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6131"></a>
<pre class="SCREEN">
---------- start of /var/yp/Makefile snippet
PRINTCAP = /etc/printcap
printcap: $(PRINTCAP)
@echo "Updating $@..."
$(CAT) $(PRINTCAP) | \
/usr/lib/yp/normalize_printcap | $(DBLOAD) -i $(PRINTCAP) \
-o $(YPMAPDIR)/$@ - $@
@if [ ! $(NOPUSH) ]; then $(YPPUSH) -d $(DOMAIN) $@; fi
@if [ ! $(NOPUSH) ]; then echo "Pushed $@ map." ; fi
---------- end of /var/yp/Makefile snippet
</pre>
</div>
<br>
<br>
</li>
<li>
<p>Install the programs <b class=
"APPLICATION">match_printcap</b> and <b class=
"APPLICATION">normalize_printcap</b> in the <tt class=
"FILENAME">/usr/lib/yp</tt> directory; <b class=
"APPLICATION">normalize_printcap</b> is only required
on the YP server. The <b class=
"APPLICATION">normalize_printcap</b> processes only the
<b class="APPLICATION">LPRng</b> printcap format.</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6141"></a>
<pre class="SCREEN">
---------- start of /usr/lib/yp/normalize_printcap
#! /usr/bin/perl
$debug = 0;
$line = "";
$new = "";
while (<>) {
chomp;
next if ( /^\s*\#.*/ );
s/^\s*$//;
next if ( $_ eq '' );
print "new: " . $_ . "\n" if $debug;;
if (/^\s/) { # continuation line
$line = $line.$_;
print "continued: $line\n" if $debug;
next;
} else {
$line =~ s/\s+\:/:/g;
$line =~ s/\:\s+/:/g;
$line =~ s/\:\s*\:/:/g;
print "line: $line\n" if $debug;
push(@lines, $line) if $line;
$line = $_;
}
}
$line =~ s/\s+\:/:/g;
$line =~ s/\:\s+/:/g;
$line =~ s/\:\s*\:/:/g;
push(@lines,$line) if $line;
@lines = sort(@lines);
foreach $line (@lines) {
($printers) = split(/\:/,$line);
@printers = split(/\|/,$printers);
foreach $printer (@printers) {
$num{$printer}++;
push(@allprinters,$printer);
print "allprinters: @allprinters\n" if $debug;
print $printer."_".$num{$printer}."\t$line\n";
}
}
@pr = keys %num;
print "printers @pr\n" if $debug;
if ($#allprinters >=0) {
print "all_1\tall:all=".join(",",@pr)."\n";
}
---------- end of /usr/lib/yp/normalize_printcap
</pre>
</div>
<br>
<br>
<p>The result of processing the sample printcap file
is:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6144"></a>
<pre class="SCREEN">
lp1_1 lp1:lp=lp1@server
lp1_2 lp1:server:oh=servername:sd=/var/spool/lpd/lp1:lp=/dev/lp1:mx=0
lp2_1 lp2:lp=lp2@server
all_1 all:all=lp1,lp2
</pre>
</div>
<br>
<br>
<p>Observe that each of the real printer entries has a
key consisting of the printer name with a numerical
suffix. This leads to the following method of
extracting the printcap information using <tt class=
"LITERAL">ypmatch</tt>:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6148"></a>
<pre class="SCREEN">
---------- start of /usr/lib/yp/match_printcap
#!/bin/sh
read p
n=1
# specify the full pathname to ypmatch - this depends on your
# OS version and installation
while /full/pathname/to/ypmatch "${p}_${n}" printcap 2>/dev/null; do
n=`expr $n + 1`
done
---------- end of /usr/lib/yp/match_printcap
</pre>
</div>
<br>
<br>
</li>
<li>
<p>Now test the YP arrangement:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6152"></a>
<pre class="SCREEN">
<tt class="PROMPT">h4: {316} #</tt> cd /var/yp; make
# this should create the printcap map
<tt class="PROMPT">h4: {317} #</tt> ypcat printcap
# should provide the whole normalized printcap
<tt class=
"PROMPT">h4: {318} #</tt> echo lp1 |/usr/lib/yp/match_printcap
# yields lp1 printcap
</pre>
</div>
<br>
<br>
</li>
<li>
<p>Modify the <tt class="LITERAL">printcap_path</tt>
entry in the <tt class="FILENAME">lpd.conf</tt>
file:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6161"></a>
<pre class="SCREEN">
printcap_path=|/usr/lib/yp/match_printcap
</pre>
</div>
<br>
<br>
</li>
<li>
<p>Test the use of the printcap path entry:</p>
<div class="INFORMALEXAMPLE">
<a name="AEN6165"></a>
<pre class="SCREEN">
<tt class=
"PROMPT">h4: {319} #</tt> lpc client lp1 # shows the printcap for lp1
<tt class=
"PROMPT">h4: {320} #</tt> lpc server lp1 # shows the printcap for lp1
</pre>
</div>
<br>
<br>
</li>
<li>
<p>Restart the lpd server and check to see that it
accesses the right printcap information. Use the same
<b class="APPLICATION">lpq</b> command, and then try
<tt class="COMMAND">lpc printcap lp1</tt>.</p>
</li>
</ol>
<br>
<br>
</div>
</div>
<div class="NAVFOOTER">
<hr align="LEFT" width="100%">
<table summary="Footer navigation table" width="100%" border=
"0" cellpadding="0" cellspacing="0">
<tr>
<td width="33%" align="left" valign="top"><a href=
"x6063.htm" accesskey="P">Prev</a></td>
<td width="34%" align="center" valign="top"><a href=
"index.htm" accesskey="H">Home</a></td>
<td width="33%" align="right" valign="top"><a href=
"x6173.htm" accesskey="N">Next</a></td>
</tr>
<tr>
<td width="33%" align="left" valign="top">Management
Strategies for Large Installations</td>
<td width="34%" align="center" valign="top"><a href=
"printcapref.htm" accesskey="U">Up</a></td>
<td width="33%" align="right" valign="top">Lexmark
Printers</td>
</tr>
</table>
</div>
</body>
</html>
