CUPS-printing.html [plain text]
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 22. CUPS Printing Support</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.71.0"><link rel="start" href="index.html" title="The Official Samba-3 HOWTO and Reference Guide"><link rel="up" href="optional.html" title="Part III. Advanced Configuration"><link rel="prev" href="classicalprinting.html" title="Chapter 21. Classical Printing Support"><link rel="next" href="VFS.html" title="Chapter 23. Stackable VFS modules"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 22. CUPS Printing Support</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="classicalprinting.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="VFS.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="CUPS-printing"></a>Chapter 22. CUPS Printing Support</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Kurt</span> <span class="surname">Pfeifle</span></h3><div class="affiliation"><span class="orgname">Danka Deutschland GmbH <br></span><div class="address"><p><code class="email"><<a href="mailto:kpfeifle@danka.de">kpfeifle@danka.de</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Ciprian</span> <span class="surname">Vizitiu</span></h3><span class="contrib">drawings</span><div class="affiliation"><div class="address"><p><code class="email"><<a href="mailto:CVizitiu@gbif.org">CVizitiu@gbif.org</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Jelmer</span> <span class="othername">R.</span> <span class="surname">Vernooij</span></h3><span class="contrib">drawings</span><div class="affiliation"><span class="orgname">The Samba Team<br></span><div class="address"><p><code class="email"><<a href="mailto:jelmer@samba.org">jelmer@samba.org</a>></code></p></div></div></div></div><div><p class="pubdate"> (27 Jan 2004) </p></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="CUPS-printing.html#id392883">Introduction</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id392889">Features and Benefits</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id392940">Overview</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id393049">Basic CUPS Support Configuration</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id393149">Linking smbd with libcups.so</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id393337">Simple <code class="filename">smb.conf</code> Settings for CUPS</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id393584">More Complex CUPS <code class="filename">smb.conf</code> Settings</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id393980">Advanced Configuration</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id393994">Central Spooling vs. “<span class="quote">Peer-to-Peer</span>” Printing</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id394045">Raw Print Serving: Vendor Drivers on Windows Clients</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id394249">Installation of Windows Client Drivers</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#cups-raw">Explicitly Enable “<span class="quote">raw</span>” Printing for <span class="emphasis"><em>application/octet-stream</em></span></a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id394512">Driver Upload Methods</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id394623">Advanced Intelligent Printing with PostScript Driver Download</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#gdipost">GDI on Windows, PostScript on UNIX</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id394797">Windows Drivers, GDI, and EMF</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id394963">UNIX Printfile Conversion and GUI Basics</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#post-and-ghost">PostScript and Ghostscript</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id395287">Ghostscript: The Software RIP for Non-PostScript Printers</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id395426">PostScript Printer Description (PPD) Specification</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id395495">Using Windows-Formatted Vendor PPDs</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id395604">CUPS Also Uses PPDs for Non-PostScript Printers</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id395639">The CUPS Filtering Architecture</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id395860">MIME Types and CUPS Filters</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id396270">MIME Type Conversion Rules</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id396465">Filtering Overview</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id396616">Prefilters</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id396793">pstops</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id396952">pstoraster</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id397202">imagetops and imagetoraster</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id397282">rasterto [printers specific]</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id397494">CUPS Backends</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id397802">The Role of <em class="parameter"><code>cupsomatic/foomatic</code></em></a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id398021">The Complete Picture</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id398033"><code class="filename">mime.convs</code></a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id398094">“<span class="quote">Raw</span>” Printing</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id398194">application/octet-stream Printing</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id398455">PostScript Printer Descriptions for Non-PostScript Printers</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id398718"><span class="emphasis"><em>cupsomatic/foomatic-rip</em></span> Versus <span class="emphasis"><em>Native CUPS</em></span> Printing</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id399033">Examples for Filtering Chains</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id399434">Sources of CUPS Drivers/PPDs</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id399543">Printing with Interface Scripts</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id399622">Network Printing (Purely Windows)</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id399636">From Windows Clients to an NT Print Server</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id399694">Driver Execution on the Client</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id399759">Driver Execution on the Server</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id399858">Network Printing (Windows Clients and UNIX/Samba Print
Servers)</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id399874">From Windows Clients to a CUPS/Samba Print Server</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id400039">Samba Receiving Job-Files and Passing Them to CUPS</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id400108">Network PostScript RIP</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id400187">PPDs for Non-PS Printers on UNIX</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id400224">PPDs for Non-PS Printers on Windows</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id400285">Windows Terminal Servers (WTS) as CUPS Clients</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id400296">Printer Drivers Running in “<span class="quote">Kernel Mode</span>” Cause Many
Problems</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id400328">Workarounds Impose Heavy Limitations</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id400341">CUPS: A “<span class="quote">Magical Stone</span>”?</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id400378">PostScript Drivers with No Major Problems, Even in Kernel
Mode</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id400456">Configuring CUPS for Driver Download</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id400475"><span class="emphasis"><em>cupsaddsmb</em></span>: The Unknown Utility</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id400563">Prepare Your <code class="filename">smb.conf</code> for <code class="literal">cupsaddsmb</code></a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id400868">CUPS “<span class="quote">PostScript Driver for Windows NT/200x/XP</span>”</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id401090">Recognizing Different Driver Files</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id401201">Acquiring the Adobe Driver Files</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id401221">ESP Print Pro PostScript Driver for Windows NT/200x/XP</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id401275">Caveats to Be Considered</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id401555">Windows CUPS PostScript Driver Versus Adobe Driver</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id401750">Run cupsaddsmb (Quiet Mode)</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id401880">Run cupsaddsmb with Verbose Output</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id402011">Understanding cupsaddsmb</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id402147">How to Recognize If cupsaddsmb Completed Successfully</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id402254">cupsaddsmb with a Samba PDC</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id402332">cupsaddsmb Flowchart</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id402410">Installing the PostScript Driver on a Client</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#cups-avoidps1">Avoiding Critical PostScript Driver Settings on the Client</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id402619">Installing PostScript Driver Files Manually Using rpcclient</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id402785">A Check of the rpcclient man Page</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id402945">Understanding the rpcclient man Page</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id403037">Producing an Example by Querying a Windows Box</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id403163">Requirements for adddriver and setdriver to Succeed</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id403371">Manual Driver Installation in 15 Steps</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id404250">Troubleshooting Revisited</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id404381">The Printing <code class="filename">*.tdb</code> Files</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id404580">Trivial Database Files</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id404646">Binary Format</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id404707">Losing <code class="filename">*.tdb</code> Files</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id404753">Using <code class="literal">tdbbackup</code></a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id404864">CUPS Print Drivers from Linuxprinting.org</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id405024">foomatic-rip and Foomatic Explained</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id405729">foomatic-rip and Foomatic PPD Download and Installation</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id406151">Page Accounting with CUPS</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id406181">Setting Up Quotas</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id406232">Correct and Incorrect Accounting</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id406265">Adobe and CUPS PostScript Drivers for Windows Clients</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id406396">The page_log File Syntax</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id406532">Possible Shortcomings</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id406590">Future Developments</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id406625">Other Accounting Tools</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id406637">Additional Material</a></span></dt><dt><span class="sect1"><a href="CUPS-printing.html#id406826">Autodeletion or Preservation of CUPS Spool Files</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id406894">CUPS Configuration Settings Explained</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id406971">Preconditions</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407077">Manual Configuration</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id407111">Printing from CUPS to Windows-Attached Printers</a></span></dt><dt><span class="sect1"><a href="CUPS-printing.html#id407368">More CUPS Filtering Chains</a></span></dt><dt><span class="sect1"><a href="CUPS-printing.html#id407477">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="CUPS-printing.html#id407482">Windows 9x/Me Client Can't Install Driver</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#root-ask-loop">“<span class="quote">cupsaddsmb</span>” Keeps Asking for Root Password in Never-ending Loop</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407549">“<span class="quote">cupsaddsmb</span>” or “<span class="quote">rpcclient addriver</span>” Emit Error</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407585">“<span class="quote">cupsaddsmb</span>” Errors</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407655">Client Can't Connect to Samba Printer</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407678">New Account Reconnection from Windows 200x/XP Troubles</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407756">Avoid Being Connected to the Samba Server as the Wrong User</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407795">Upgrading to CUPS Drivers from Adobe Drivers</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407830">Can't Use “<span class="quote">cupsaddsmb</span>” on Samba Server, Which Is a PDC</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407864">Deleted Windows 200x Printer Driver Is Still Shown</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407895">Windows 200x/XP Local Security Policies</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407926">Administrator Cannot Install Printers for All Local Users</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407963">Print Change, Notify Functions on NT Clients</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id407987">Win XP-SP1</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id408028">Print Options for All Users Can't Be Set on Windows 200x/XP</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id408292">Most Common Blunders in Driver Settings on Windows Clients</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id408345"><code class="literal">cupsaddsmb</code> Does Not Work with Newly Installed Printer</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id408391">Permissions on <code class="filename">/var/spool/samba/</code> Get Reset After Each Reboot</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id408477">Print Queue Called “<span class="quote">lp</span>” Mishandles Print Jobs</a></span></dt><dt><span class="sect2"><a href="CUPS-printing.html#id408540">Location of Adobe PostScript Driver Files for “<span class="quote">cupsaddsmb</span>”</a></span></dt></dl></dd><dt><span class="sect1"><a href="CUPS-printing.html#id408591">Overview of the CUPS Printing Processes</a></span></dt></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id392883"></a>Introduction</h2></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id392889"></a>Features and Benefits</h3></div></div></div><p>
<a class="indexterm" name="id392897"></a>
The Common UNIX Print System (<a href="http://www.cups.org/" target="_top">CUPS</a>)
has become quite popular. All major Linux distributions now ship it as their default printing
system. To many, it is still a mystical tool. Mostly, it just works. People tend to regard
it as a “<span class="quote">black box</span>” that they do not want to look into as long as it works. But once
there is a little problem, they have trouble finding out where to start debugging it. Refer to
<a href="classicalprinting.html" title="Chapter 21. Classical Printing Support">Classical Printing</a>, which contains much information
that is also relevant to CUPS.
</p><p>
<a class="indexterm" name="id392927"></a>
CUPS sports quite a few unique and powerful features. While its basic functions may be grasped quite
easily, they are also new. Because it is different from other, more traditional printing systems, it is best
not to try to apply any prior knowledge about printing to this new system. Rather, try to understand CUPS from
the beginning. This documentation will lead you to a complete understanding of CUPS. Let's start with the most
basic things first.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id392940"></a>Overview</h3></div></div></div><p>
<a class="indexterm" name="id392948"></a>
<a class="indexterm" name="id392954"></a>
<a class="indexterm" name="id392961"></a>
<a class="indexterm" name="id392968"></a>
<a class="indexterm" name="id392975"></a>
<a class="indexterm" name="id392984"></a>
<a class="indexterm" name="id392994"></a>
<a class="indexterm" name="id393000"></a>
CUPS is more than just a print spooling system. It is a complete printer management system that
complies with the new Internet Printing Protocol (IPP). IPP is an industry and Internet Engineering Task Force
(IETF) standard for network printing. Many of its functions can be managed remotely (or locally) via a Web
browser (giving you platform-independent access to the CUPS print server). Additionally, it has the
traditional command line and several more modern GUI interfaces (GUI interfaces developed by third parties,
like KDE's overwhelming <a href="http://printing.kde.org/" target="_top">KDEPrint</a>).
</p><p>
<a class="indexterm" name="id393021"></a>
<a class="indexterm" name="id393028"></a>
CUPS allows creation of <span class="emphasis"><em>raw</em></span> printers (i.e., no print file format translation) as
well as <span class="emphasis"><em>smart</em></span> printers (i.e., CUPS does file format conversion as required for the
printer). In many ways, this gives CUPS capabilities similar to the MS Windows print monitoring system. Of
course, if you are a CUPS advocate, you would argue that CUPS is better! In any case, let us now explore how
to configure CUPS for interfacing with MS Windows print clients via Samba.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id393049"></a>Basic CUPS Support Configuration</h2></div></div></div><p>
<a class="indexterm" name="id393057"></a>
<a class="indexterm" name="id393063"></a>
<a class="indexterm" name="id393070"></a>
<a class="indexterm" name="id393077"></a>
<a class="indexterm" name="id393084"></a>
Printing with CUPS in the most basic <code class="filename">smb.conf</code> setup in Samba-3.0 (as was true for 2.2.x) requires just two
parameters: <a class="indexterm" name="id393098"></a>printing = cups and <a class="indexterm" name="id393105"></a>printcap = cups. CUPS does not need a printcap file. However, the
<code class="filename">cupsd.conf</code> configuration file knows of two related directives that control how such a
file will be automatically created and maintained by CUPS for the convenience of third-party applications
(example: <em class="parameter"><code>Printcap /etc/printcap</code></em> and <em class="parameter"><code>PrintcapFormat BSD</code></em>).
Legacy programs often require the existence of a printcap file containing printer names or they will refuse to
print. Make sure CUPS is set to generate and maintain a printcap file. For details, see <code class="literal">man
cupsd.conf</code> and other CUPS-related documentation, like the wealth of documents regarding the CUPS
server itself available from the <a href="http://localhost:631/documentation.html" target="_top">CUPS</a> web site.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id393149"></a>Linking smbd with libcups.so</h3></div></div></div><p>
<a class="indexterm" name="id393157"></a>
Samba has a special relationship to CUPS. Samba can be compiled with CUPS library support.
Most recent installations have this support enabled. By default, CUPS linking is compiled
into smbd and other Samba binaries. Of course, you can use CUPS even
if Samba is not linked against <code class="filename">libcups.so</code> but
there are some differences in required or supported configuration.
</p><p>
<a class="indexterm" name="id393179"></a>
<a class="indexterm" name="id393186"></a>
When Samba is compiled and linked with <code class="filename">libcups</code>, <a class="indexterm" name="id393198"></a>printcap = cups
uses the CUPS API to list printers, submit jobs, query queues, and so on. Otherwise it maps to the System V
commands with an additional <code class="literal">-oraw</code> option for printing. On a Linux
system, you can use the <code class="literal">ldd</code> utility to find out if smbd has been linked with the
libcups library (<code class="literal">ldd</code> may not be present on other OS platforms, or its function may be embodied
by a different command):
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>ldd `which smbd`</code></strong>
libssl.so.0.9.6 => /usr/lib/libssl.so.0.9.6 (0x4002d000)
libcrypto.so.0.9.6 => /usr/lib/libcrypto.so.0.9.6 (0x4005a000)
libcups.so.2 => /usr/lib/libcups.so.2 (0x40123000)
[....]
</pre><p>
</p><p>
<a class="indexterm" name="id393246"></a>
The line <code class="computeroutput">libcups.so.2 => /usr/lib/libcups.so.2 (0x40123000)</code> shows
there is CUPS support compiled into this version of Samba. If this is the case, and printing = cups
is set, then <span class="emphasis"><em>any otherwise manually set print command in <code class="filename">smb.conf</code> is ignored</em></span>.
This is an important point to remember!
</p><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3><p> Should it be necessary, for any reason, to set your own print commands, you can do this by setting
<a class="indexterm" name="id393277"></a>printing = sysv. However, you will lose all the benefits
of tight CUPS-Samba integration. When you do this, you must manually configure the printing system commands
(most important:
<a class="indexterm" name="id393285"></a>print command; other commands are
<a class="indexterm" name="id393293"></a>lppause command,
<a class="indexterm" name="id393300"></a>lpresume command,
<a class="indexterm" name="id393307"></a>lpq command,
<a class="indexterm" name="id393314"></a>lprm command,
<a class="indexterm" name="id393321"></a>queuepause command and
<a class="indexterm" name="id393328"></a>queue resume command).
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id393337"></a>Simple <code class="filename">smb.conf</code> Settings for CUPS</h3></div></div></div><p>
To summarize, <a href="CUPS-printing.html#cups-exam-simple" title="Example 22.1. Simplest Printing-Related smb.conf">the Simplest Printing-Related
<code class="filename">smb.conf</code> file</a> shows the simplest printing-related setup for <code class="filename">smb.conf</code> to
enable basic CUPS support:
</p><div class="example"><a name="cups-exam-simple"></a><p class="title"><b>Example 22.1. Simplest Printing-Related smb.conf</b></p><div class="example-contents"><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td><a class="indexterm" name="id393397"></a><em class="parameter"><code>load printers = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393410"></a><em class="parameter"><code>printing = cups</code></em></td></tr><tr><td><a class="indexterm" name="id393422"></a><em class="parameter"><code>printcap name = cups</code></em></td></tr><tr><td> </td></tr><tr><td><em class="parameter"><code>[printers]</code></em></td></tr><tr><td><a class="indexterm" name="id393444"></a><em class="parameter"><code>comment = All Printers</code></em></td></tr><tr><td><a class="indexterm" name="id393456"></a><em class="parameter"><code>path = /var/spool/samba</code></em></td></tr><tr><td><a class="indexterm" name="id393469"></a><em class="parameter"><code>browseable = no</code></em></td></tr><tr><td><a class="indexterm" name="id393481"></a><em class="parameter"><code>public = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393494"></a><em class="parameter"><code>guest ok = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393506"></a><em class="parameter"><code>writable = no</code></em></td></tr><tr><td><a class="indexterm" name="id393519"></a><em class="parameter"><code>printable = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393531"></a><em class="parameter"><code>printer admin = root, @ntadmins</code></em></td></tr></table></div></div><br class="example-break"><p>
<a class="indexterm" name="id393547"></a>
<a class="indexterm" name="id393554"></a>
<a class="indexterm" name="id393561"></a>
This is all you need for basic printing setup for CUPS. It will print all graphic, text, PDF, and PostScript
files submitted from Windows clients. However, most of your Windows users would not know how to send these
kinds of files to print without opening a GUI application. Windows clients tend to have local printer drivers
installed, and the GUI application's print buttons start a printer driver. Your users also rarely send files
from the command line. Unlike UNIX clients, they rarely submit graphic, text, or PDF formatted files directly
to the spooler. They nearly exclusively print from GUI applications with a “<span class="quote">printer driver</span>”
hooked between the application's native format and the print data stream. If the backend printer is not a
PostScript device, the print data stream is “<span class="quote">binary,</span>” sensible only for the target printer. Read
on to learn what problem this may cause and how to avoid it.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id393584"></a>More Complex CUPS <code class="filename">smb.conf</code> Settings</h3></div></div></div><p>
<a href="CUPS-printing.html#overridesettings" title="Example 22.2. Overriding Global CUPS Settings for One Printer">The Overriding Global CUPS Settings for One Printer example</a>
is a slightly more complex printing-related setup for <code class="filename">smb.conf</code>. It enables general CUPS printing
support for all printers, but defines one printer share, which is set up differently.
</p><div class="example"><a name="overridesettings"></a><p class="title"><b>Example 22.2. Overriding Global CUPS Settings for One Printer</b></p><div class="example-contents"><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td><a class="indexterm" name="id393638"></a><em class="parameter"><code>printing = cups</code></em></td></tr><tr><td><a class="indexterm" name="id393651"></a><em class="parameter"><code>printcap name = cups</code></em></td></tr><tr><td><a class="indexterm" name="id393663"></a><em class="parameter"><code>load printers = yes</code></em></td></tr><tr><td> </td></tr><tr><td><em class="parameter"><code>[printers]</code></em></td></tr><tr><td><a class="indexterm" name="id393685"></a><em class="parameter"><code>comment = All Printers</code></em></td></tr><tr><td><a class="indexterm" name="id393697"></a><em class="parameter"><code>path = /var/spool/samba</code></em></td></tr><tr><td><a class="indexterm" name="id393710"></a><em class="parameter"><code>public = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393722"></a><em class="parameter"><code>guest ok = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393735"></a><em class="parameter"><code>writable = no</code></em></td></tr><tr><td><a class="indexterm" name="id393747"></a><em class="parameter"><code>printable = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393760"></a><em class="parameter"><code>printer admin = root, @ntadmins</code></em></td></tr><tr><td> </td></tr><tr><td><em class="parameter"><code>[special_printer]</code></em></td></tr><tr><td><a class="indexterm" name="id393781"></a><em class="parameter"><code>comment = A special printer with his own settings</code></em></td></tr><tr><td><a class="indexterm" name="id393794"></a><em class="parameter"><code>path = /var/spool/samba-special</code></em></td></tr><tr><td><a class="indexterm" name="id393807"></a><em class="parameter"><code>printing = sysv</code></em></td></tr><tr><td><a class="indexterm" name="id393819"></a><em class="parameter"><code>printcap = lpstat</code></em></td></tr><tr><td><a class="indexterm" name="id393832"></a><em class="parameter"><code>print command = echo "NEW: `date`: printfile %f" >> /tmp/smbprn.log ; echo " `date`: p-%p s-%s f-%f" >> /tmp/smbprn.log ; echo " `date`: j-%j J-%J z-%z c-%c" >> /tmp/smbprn.log ; rm %f </code></em></td></tr><tr><td><a class="indexterm" name="id393847"></a><em class="parameter"><code>public = no</code></em></td></tr><tr><td><a class="indexterm" name="id393859"></a><em class="parameter"><code>guest ok = no</code></em></td></tr><tr><td><a class="indexterm" name="id393872"></a><em class="parameter"><code>writable = no</code></em></td></tr><tr><td><a class="indexterm" name="id393884"></a><em class="parameter"><code>printable = yes</code></em></td></tr><tr><td><a class="indexterm" name="id393897"></a><em class="parameter"><code>printer admin = kurt</code></em></td></tr><tr><td><a class="indexterm" name="id393910"></a><em class="parameter"><code>hosts deny = 0.0.0.0</code></em></td></tr><tr><td><a class="indexterm" name="id393922"></a><em class="parameter"><code>hosts allow = turbo_xp, 10.160.50.23, 10.160.51.60</code></em></td></tr></table></div></div><br class="example-break"><p>
This special share is only for testing purposes. It does not write the print job to a file. It just logs the job parameters
known to Samba into the <code class="filename">/tmp/smbprn.log</code> file and deletes the job-file. Moreover, the
<a class="indexterm" name="id393946"></a>printer admin of this share is “<span class="quote">kurt</span>” (not the “<span class="quote">@ntadmins</span>” group),
guest access is not allowed, the share isn't published to the Network Neighborhood (so you need to know it is there), and it
allows access from only three hosts. To prevent CUPS from kicking in and taking over the print jobs for that share, we need to set
<a class="indexterm" name="id393962"></a>printing = sysv and <a class="indexterm" name="id393970"></a>printcap = lpstat.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id393980"></a>Advanced Configuration</h2></div></div></div><p>
Before we delve into all the configuration options, let us clarify a few points. <span class="emphasis"><em>Network printing
needs to be organized and set up correctly</em></span>. This frequently doesn't happen. Legacy systems or small
business LAN environments often lack design and good housekeeping.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id393994"></a>Central Spooling vs. “<span class="quote">Peer-to-Peer</span>” Printing</h3></div></div></div><p>
<a class="indexterm" name="id394006"></a>
<a class="indexterm" name="id394013"></a>
<a class="indexterm" name="id394022"></a>
Many small office or home networks, as well as badly organized larger environments, allow each client a direct
access to available network printers. This is generally a bad idea. It often blocks one client's access to the
printer when another client's job is printing. It might freeze the first client's application while it is
waiting to get rid of the job. Also, there are frequent complaints about various jobs being printed with their
pages mixed with each other. A better concept is the use of a print server: it routes all jobs through one
central system, which responds immediately, takes jobs from multiple concurrent clients, and transfers them to
the printer(s) in the correct order.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id394045"></a>Raw Print Serving: Vendor Drivers on Windows Clients</h3></div></div></div><p>
<a class="indexterm" name="id394053"></a>
<a class="indexterm" name="id394060"></a>
Most traditionally configured UNIX print servers acting on behalf of
Samba's Windows clients represented a really simple setup. Their only
task was to manage the “<span class="quote">raw</span>” spooling of all jobs handed to them by
Samba. This approach meant that the Windows clients were expected to
prepare the print job file that is ready to be sent to the printing
device. In this case, a native (vendor-supplied) Windows printer driver needs to
be installed on each and every client for the target device.
</p><p>
<a class="indexterm" name="id394077"></a>
<a class="indexterm" name="id394084"></a>
It is possible to configure CUPS, Samba, and your Windows clients in the
same traditional and simple way. When CUPS printers are configured
for raw print-through mode operation, it is the responsibility of the
Samba client to fully render the print job (file). The file must be
sent in a format that is suitable for direct delivery to the
printer. Clients need to run the vendor-provided drivers to do
this. In this case, CUPS will not do any print file format conversion
work.
</p><p>
The easiest printing configuration possible is raw print-through.
This is achieved by installation of the printer as if it were physically
attached to the Windows client. You then redirect output to a raw network
print queue. This procedure may be followed to achieve this:
</p><div class="procedure"><a name="id394102"></a><p class="title"><b>Procedure 22.1. Configuration Steps for Raw CUPS Printing Support</b></p><ol type="1"><li><p>
<a class="indexterm" name="id394113"></a>
Edit <code class="filename">/etc/cups/mime.types</code> to uncomment the line
near the end of the file that has:
</p><pre class="screen">
#application/octet-...
</pre><p>
</p></li><li><p>
<a class="indexterm" name="id394139"></a>
Do the same for the file <code class="filename">/etc/cups/mime.convs</code>.
</p></li><li><p>
Add a raw printer using the Web interface. Point your browser at
<code class="constant">http://localhost:631</code>. Enter Administration, and add
the printer following the prompts. Do not install any drivers for it.
Choose Raw. Choose queue name <code class="constant">Raw Queue</code>.
</p></li><li><p>
In the <code class="filename">smb.conf</code> file <code class="constant">[printers]</code> section add
<a class="indexterm" name="id394185"></a>use client driver = Yes,
and in the <code class="constant">[global]</code> section add
<a class="indexterm" name="id394196"></a>printing = CUPS, plus
<a class="indexterm" name="id394203"></a>printcap = CUPS.
</p></li><li><p>
Install the printer as if it is a local printer, that is, Printing to <code class="constant">LPT1:</code>.
</p></li><li><p>
Edit the configuration under the <span class="guimenu">Detail</span> tab and create a
<code class="constant">local port</code> that points to the raw printer queue that
you have configured above. Example: <code class="constant">\\server\raw_q</code>.
Here, the name <code class="constant">raw_q</code> is the name you gave the print
queue in the CUPS environment.
</p></li></ol></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id394249"></a>Installation of Windows Client Drivers</h3></div></div></div><p>
The printer drivers on the Windows clients may be installed
in two functionally different ways:
</p><div class="itemizedlist"><ul type="disc"><li><p>Manually install the drivers locally on each client,
one by one; this yields the old LanMan style
printing and uses a <code class="filename">\\sambaserver\printershare</code>
type of connection.</p></li><li><p>
<a class="indexterm" name="id394276"></a>
Deposit and prepare the drivers (for later download) on
the print server (Samba); this enables the clients to use
“<span class="quote">Point'n'Print</span>” to get drivers semi-automatically installed the
first time they access the printer; with this method NT/200x/XP
clients use the <span class="emphasis"><em>SPOOLSS/MS-RPC</em></span>
type printing calls.</p></li></ul></div><p>
The second method is recommended for use over the first.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cups-raw"></a>Explicitly Enable “<span class="quote">raw</span>” Printing for <span class="emphasis"><em>application/octet-stream</em></span></h3></div></div></div><p>
<a class="indexterm" name="id394316"></a>
<a class="indexterm" name="id394323"></a>
<a class="indexterm" name="id394330"></a>
If you use the first option (drivers are installed on the client
side), there is one setting to take care of: CUPS needs to be told
that it should allow “<span class="quote">raw</span>” printing of deliberate (binary) file
formats. The CUPS files that need to be correctly set for raw mode
printers to work are:
</p><div class="itemizedlist"><ul type="disc"><li><p><code class="filename">/etc/cups/mime.types</code></p></li><li><p><code class="filename">/etc/cups/mime.convs</code></p></li></ul></div><p>
Both contain entries (at the end of the respective files) that must be uncommented to allow RAW mode
operation. In <code class="filename">/etc/cups/mime.types</code>, make sure this line is present:
</p><pre class="programlisting">
application/octet-stream
</pre><p>
<a class="indexterm" name="id394380"></a>
<a class="indexterm" name="id394387"></a>
In <code class="filename">/etc/cups/mime.convs</code>, have this line:
<a class="indexterm" name="id394400"></a>
</p><pre class="programlisting">
application/octet-stream application/vnd.cups-raw 0 -
</pre><p>
If these two files are not set up correctly for raw Windows client
printing, you may encounter the dreaded <code class="computeroutput">Unable to
convert file 0</code> in your CUPS <code class="filename">error_log</code> file.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
Editing the <code class="filename">mime.convs</code> and the <code class="filename">mime.types</code> file does
not <span class="emphasis"><em>enforce</em></span> “<span class="quote">raw</span>” printing, it only <span class="emphasis"><em>allows</em></span> it.
</p></div><p><b>Background. </b>
<a class="indexterm" name="id394461"></a>
<a class="indexterm" name="id394468"></a>
That CUPS is a more security-aware printing system than traditional ones does not by default allow a user to
send deliberate (possibly binary) data to printing devices. This could be easily abused to launch a
“<span class="quote">Denial of Service</span>” attack on your printer(s), causing at least the loss of a lot of paper and
ink. “<span class="quote">Unknown</span>” data are tagged by CUPS as <em class="parameter"><code>MIME type: application/octet-stream</code></em>
and not allowed to go to the printer. By default, you can only send other (known) MIME types “<span class="quote">raw.</span>”
Sending data “<span class="quote">raw</span>” means that CUPS does not try to convert them and passes them to the printer
untouched.
</p><p>
This is all you need to know to get the CUPS/Samba combo printing
“<span class="quote">raw</span>” files prepared by Windows clients, which have vendor drivers
locally installed. If you are not interested in background information about
more advanced CUPS/Samba printing, simply skip the remaining sections
of this chapter.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id394512"></a>Driver Upload Methods</h3></div></div></div><p>
This section describes three familiar methods, plus one new one, by which
printer drivers may be uploaded.
</p><p>
<a class="indexterm" name="id394524"></a>
If you want to use the MS-RPC-type printing, you must upload the
drivers onto the Samba server first (<em class="parameter"><code>[print$]</code></em>
share). For a discussion on how to deposit printer drivers on the
Samba host (so the Windows clients can download and use them via
“<span class="quote">Point'n'Print</span>”), please refer to the <a href="classicalprinting.html" title="Chapter 21. Classical Printing Support">Classical Printing
chapter</a> of this book. There you will find a description or reference to
three methods of preparing the client drivers on the Samba server:
</p><div class="itemizedlist"><ul type="disc"><li><p>
<a class="indexterm" name="id394557"></a>
The GUI, “<span class="quote">Add Printer Wizard</span>” <span class="emphasis"><em>upload-from-a-Windows-client</em></span> method.
</p></li><li><p>
The command line, “<span class="quote">smbclient/rpcclient</span>” upload-from-a-UNIX-workstation method.
</p></li><li><p>
<a class="indexterm" name="id394584"></a>
The Imprints tool set method.
</p></li></ul></div><p>
<a class="indexterm" name="id394595"></a>
These three methods apply to CUPS all the same. The <code class="literal">cupsaddsmb</code> utility is a new and more
convenient way to load the Windows drivers into Samba and is provided if you use CUPS.
</p><p>
<code class="literal">cupsaddsmb</code> is discussed in much detail later in this chapter. But we first
explore the CUPS filtering system and compare the Windows and UNIX printing architectures.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id394623"></a>Advanced Intelligent Printing with PostScript Driver Download</h2></div></div></div><p>
<a class="indexterm" name="id394631"></a>
We now know how to set up a “<span class="quote">dump</span>” print server, that is, a server that spools
print jobs “<span class="quote">raw</span>”, leaving the print data untouched.
</p><p>
You might need to set up CUPS in a smarter way. The reasons could be manifold:
</p><a class="indexterm" name="id394654"></a><a class="indexterm" name="id394660"></a><a class="indexterm" name="id394667"></a><div class="itemizedlist"><ul type="disc"><li><p>Maybe your boss wants to get monthly statistics: Which
printer did how many pages? What was the average data size of a job?
What was the average print run per day? What are the typical hourly
peaks in printing? Which department prints how much?</p></li><li><p>Maybe you are asked to set up a print quota system:
Users should not be able to print more jobs once they have surpassed
a given limit per period.</p></li><li><p>Maybe your previous network printing setup is a mess
and must be re-organized from a clean beginning.</p></li><li><p>Maybe you are experiencing too many “<span class="quote">blue screens</span>”
originating from poorly debugged printer drivers running in NT “<span class="quote">kernel mode</span>”?</p></li></ul></div><p>
These goals cannot be achieved by a raw print server. To build a
server meeting these requirements, you'll first need to learn
how CUPS works and how you can enable its features.
</p><p>
What follows is the comparison of some fundamental concepts for
Windows and UNIX printing, then a description of the
CUPS filtering system, how it works, and how you can tweak it.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="gdipost"></a>GDI on Windows, PostScript on UNIX</h3></div></div></div><p>
<a class="indexterm" name="id394728"></a>
<a class="indexterm" name="id394735"></a>
Network printing is one of the most complicated and error-prone
day-to-day tasks any user or administrator may encounter. This is
true for all OS platforms, and there are reasons it is so.
</p><p>
<a class="indexterm" name="id394746"></a>
<a class="indexterm" name="id394753"></a>
<a class="indexterm" name="id394759"></a>
<a class="indexterm" name="id394766"></a>
<a class="indexterm" name="id394773"></a>
You can't expect to throw just any file format at a printer and have it get printed. A file format conversion
must take place. The problem is that there is no common standard for print file formats across all
manufacturers and printer types. While PostScript (trademark held by Adobe) and, to an extent, PCL (trademark
held by Hewlett-Packard) have developed into semi-official “<span class="quote">standards</span>” by being the most widely
used page description languages (PDLs), there are still many manufacturers who “<span class="quote">roll their own</span>”
(their reasons may be unacceptable license fees for using printer-embedded PostScript interpreters, and so on).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id394797"></a>Windows Drivers, GDI, and EMF</h3></div></div></div><p>
<a class="indexterm" name="id394804"></a>
<a class="indexterm" name="id394811"></a>
<a class="indexterm" name="id394818"></a>
<a class="indexterm" name="id394824"></a>
In Windows OS, the format conversion job is done by the printer drivers. On MS Windows OS platforms all
application programmers have at their disposal a built-in API, the graphical device interface (GDI), as part
and parcel of the OS itself to base themselves on. This GDI core is used as one common unified ground for all
Windows programs to draw pictures, fonts, and documents <span class="emphasis"><em>on screen</em></span> as well as <span class="emphasis"><em>on
paper</em></span> (print). Therefore, printer driver developers can standardize on a well-defined GDI output
for their own driver input. Achieving WYSIWYG (What You See Is What You Get) is relatively easy, because the
on-screen graphic primitives, as well as the on-paper drawn objects, come from one common source. This source,
the GDI, often produces a file format called Enhanced MetaFile (EMF). The EMF is processed by the printer
driver and converted to the printer-specific file format.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id394852"></a>
<a class="indexterm" name="id394859"></a>
<a class="indexterm" name="id394866"></a>
To the GDI foundation in MS Windows, Apple has chosen to put paper and screen output on a common foundation
for its (BSD-UNIX-based, did you know?) Mac OS X and Darwin operating <a class="indexterm" name="id394874"></a> <a class="indexterm" name="id394881"></a>
<a class="indexterm" name="id394888"></a> <a class="indexterm" name="id394894"></a> systems.
Apple's <span class="emphasis"><em>core graphic engine</em></span> uses a <span class="emphasis"><em>PDF</em></span> derivative for all display work.
</p></div><p>
The example in <a href="CUPS-printing.html#1small" title="Figure 22.1. Windows Printing to a Local Printer.">Windows Printing to a Local Printer</a> illustrates local Windows
printing.
</p><div class="figure"><a name="1small"></a><p class="title"><b>Figure 22.1. Windows Printing to a Local Printer.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/1small.png" alt="Windows Printing to a Local Printer."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id394963"></a>UNIX Printfile Conversion and GUI Basics</h3></div></div></div><p>
<a class="indexterm" name="id394971"></a>
<a class="indexterm" name="id394978"></a>
<a class="indexterm" name="id394984"></a>
<a class="indexterm" name="id394991"></a>
In UNIX and Linux, there is no comparable layer built into the OS kernel(s) or the X (screen display) server.
Every application is responsible for itself to create its print output. Fortunately, most use PostScript and
that at least gives some common ground. Unfortunately, there are many different levels of quality for this
PostScript. And worse, there is a huge difference (and no common root) in the way the same document is
displayed on screen and how it is presented on paper. WYSIWYG is more difficult to achieve. This goes back to
the time, decades ago, when the predecessors of X.org, designing the UNIX foundations and protocols for
graphical user interfaces, refused to take responsibility for “<span class="quote">paper output</span>”, as some had
demanded at the time, and restricted itself to “<span class="quote">on-screen only.</span>” (For some years now, the
“<span class="quote">Xprint</span>” project has been under development, attempting to build printing support into the X
framework, including a PostScript and a PCL driver, but it is not yet ready for prime time.) You can see this
unfavorable inheritance up to the present day by looking into the various “<span class="quote">font</span>” directories on
your system; there are separate ones for fonts used for X display and fonts to be used on paper.
</p><p><b>Background. </b>
<a class="indexterm" name="id395031"></a>
<a class="indexterm" name="id395038"></a>
<a class="indexterm" name="id395045"></a>
<a class="indexterm" name="id395051"></a>
<a class="indexterm" name="id395058"></a>
<a class="indexterm" name="id395065"></a>
<a class="indexterm" name="id395072"></a>
<a class="indexterm" name="id395079"></a>
<a class="indexterm" name="id395085"></a>
<a class="indexterm" name="id395092"></a>
The PostScript programming language is an “<span class="quote">invention</span>” by Adobe, but its specifications have been
published extensively. Its strength lies in its powerful abilities to describe graphical objects (fonts,
shapes, patterns, lines, curves, and dots), their attributes (color, linewidth), and the way to manipulate
(scale, distort, rotate, shift) them. Because of its open specification, anybody with the skill can start
writing his or her own implementation of a PostScript interpreter and use it to display PostScript files on
screen or on paper. Most graphical output devices are based on the concept of “<span class="quote">raster images</span>” or
“<span class="quote">pixels</span>” (one notable exception is pen plotters). Of course, you can look at a PostScript file in
its textual form and you will be reading its PostScript code, the language instructions that need to be
interpreted by a rasterizer. Rasterizers produce pixel images, which may be displayed on screen by a viewer
program or on paper by a printer.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="post-and-ghost"></a>PostScript and Ghostscript</h3></div></div></div><p>
<a class="indexterm" name="id395133"></a>
<a class="indexterm" name="id395139"></a>
<a class="indexterm" name="id395148"></a>
<a class="indexterm" name="id395158"></a>
<a class="indexterm" name="id395164"></a>
So UNIX is lacking a common ground for printing on paper and displaying on screen. Despite this unfavorable
legacy for UNIX, basic printing is fairly easy if you have PostScript printers at your disposal. The reason is
that these devices have a built-in PostScript language “<span class="quote">interpreter,</span>” also called a raster image
processor (RIP), (which makes them more expensive than other types of printers; throw PostScript toward them,
and they will spit out your printed pages. The RIP does all the hard work of converting the PostScript drawing
commands into a bitmap picture as you see it on paper, in a resolution as done by your printer. This is no
different than PostScript printing a file from a Windows origin.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id395187"></a>
<a class="indexterm" name="id395194"></a>
<a class="indexterm" name="id395200"></a>
Traditional UNIX programs and printing systems while using PostScript are largely not
PPD-aware. PPDs are “<span class="quote">PostScript Printer Description</span>” files. They enable you to specify and
control all options a printer supports: duplexing, stapling, and punching. Therefore, UNIX users for a long
time couldn't choose many of the supported device and job options, unlike Windows or Apple users. But now
there is CUPS. as illustrated in <a href="CUPS-printing.html#2small" title="Figure 22.2. Printing to a PostScript Printer.">Printing to a PostScript Printer</a>.
</p></div><div class="figure"><a name="2small"></a><p class="title"><b>Figure 22.2. Printing to a PostScript Printer.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/2small.png" alt="Printing to a PostScript Printer."></div></div></div><br class="figure-break"><p>
<a class="indexterm" name="id395274"></a>
However, there are other types of printers out there. These do not know how to print PostScript. They use
their own PDL, often proprietary. To print to them is much more demanding. Since your UNIX applications mostly
produce PostScript, and since these devices do not understand PostScript, you need to convert the print files
to a format suitable for your printer on the host before you can send it away.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id395287"></a>Ghostscript: The Software RIP for Non-PostScript Printers</h3></div></div></div><p>
<a class="indexterm" name="id395295"></a>
Here is where Ghostscript kicks in. Ghostscript is the traditional (and quite powerful) PostScript interpreter
used on UNIX platforms. It is a RIP in software, capable of doing a <span class="emphasis"><em>lot</em></span> of file format
conversions for a very broad spectrum of hardware devices as well as software file formats. Ghostscript
technology and drivers are what enable PostScript printing to non-PostScript hardware. This is shown in
<a href="CUPS-printing.html#3small" title="Figure 22.3. Ghostscript as a RIP for Non-PostScript Printers.">Ghostscript as a RIP for Non-PostScript Printers</a>.
</p><div class="figure"><a name="3small"></a><p class="title"><b>Figure 22.3. Ghostscript as a RIP for Non-PostScript Printers.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/3small.png" alt="Ghostscript as a RIP for Non-PostScript Printers."></div></div></div><br class="figure-break"><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3><p>
<a class="indexterm" name="id395360"></a>
<a class="indexterm" name="id395367"></a>
<a class="indexterm" name="id395374"></a>
Use the “<span class="quote">gs -h</span>” command to check for all built-in “<span class="quote">devices</span>” on your Ghostscript
version. If you specify a parameter of <em class="parameter"><code>-sDEVICE=png256</code></em> on your Ghostscript command
line, you are asking Ghostscript to convert the input into a PNG file. Naming a “<span class="quote">device</span>” on the
command line is the most important single parameter to tell Ghostscript exactly how it should render the
input. New Ghostscript versions are released at fairly regular intervals, now by artofcode LLC. They are
initially put under the “<span class="quote">AFPL</span>” license, but re-released under the GNU GPL as soon as the next
AFPL version appears. GNU Ghostscript is probably the version installed on most Samba systems. But it has some
deficiencies. <a class="indexterm" name="id395406"></a> Therefore, ESP Ghostscript was developed as an enhancement over GNU Ghostscript,
with lots of bug-fixes, additional devices, and improvements. It is jointly maintained by developers from
CUPS, Gimp-Print, MandrakeSoft, SuSE, Red Hat, and Debian. It includes the “<span class="quote">cups</span>” device
(essential to print to non-PS printers from CUPS).
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id395426"></a>PostScript Printer Description (PPD) Specification</h3></div></div></div><p>
<a class="indexterm" name="id395434"></a>
<a class="indexterm" name="id395441"></a>
<a class="indexterm" name="id395447"></a>
While PostScript in essence is a PDL to represent the page layout in a device-independent way, real-world
print jobs are always ending up being output on hardware with device-specific features. To take care of all
the differences in hardware and to allow for innovations, Adobe has specified a syntax and file format for
PostScript Printer Description (PPD) files. Every PostScript printer ships with one of these files.
</p><p>
PPDs contain all the information about general and special features of the
given printer model: Which different resolutions can it handle? Does
it have a duplexing unit? How many paper trays are there? What media
types and sizes does it take? For each item, it also names the special
command string to be sent to the printer (mostly inside the PostScript
file) in order to enable it.
</p><p>
Information from these PPDs is meant to be taken into account by the
printer drivers. Therefore, installed as part of the Windows
PostScript driver for a given printer is the printer's PPD. Where it
makes sense, the PPD features are presented in the drivers' UI dialogs
to display to the user a choice of print options. In the end, the
user selections are somehow written (in the form of special
PostScript, PJL, JCL, or vendor-dependent commands) into the PostScript
file created by the driver.
</p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
<a class="indexterm" name="id395476"></a>
<a class="indexterm" name="id395483"></a>
A PostScript file that was created to contain device-specific commands
for achieving a certain print job output (e.g., duplexed, stapled, and
punched) on a specific target machine may not print as expected, or
may not be printable at all on other models; it also may not be fit
for further processing by software (e.g., by a PDF distilling program).
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id395495"></a>Using Windows-Formatted Vendor PPDs</h3></div></div></div><p>
<a class="indexterm" name="id395503"></a>
<a class="indexterm" name="id395510"></a>
<a class="indexterm" name="id395516"></a>
CUPS can handle all spec-compliant PPDs as supplied by the manufacturers for their PostScript models. Even if
a vendor does not mention our favorite OS in his or her manuals and brochures, you can safely trust this:
<span class="emphasis"><em>If you get the Windows NT version of the PPD, you can use it unchanged in CUPS</em></span> and thus
access the full power of your printer just like a Windows NT user could!
</p><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3><p>
To check the spec compliance of any PPD online, go to <a href="http://www.cups.org/testppd.php" target="_top">http://www.cups.org/testppd.php</a> and upload your PPD. You will
see the results displayed immediately. CUPS in all versions after 1.1.19 has a much stricter internal PPD
parsing and checking code enabled; in case of printing trouble, this online resource should be one of your
first pit stops.
</p></div><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
<a class="indexterm" name="id395550"></a>
<a class="indexterm" name="id395556"></a>
For real PostScript printers, <span class="emphasis"><em>do not</em></span> use the <span class="emphasis"><em>Foomatic</em></span> or
<span class="emphasis"><em>cupsomatic</em></span> PPDs from Linuxprinting.org. With these devices, the original vendor-provided
PPDs are always the first choice.
</p></div><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3><p>
<a class="indexterm" name="id395580"></a>
If you are looking for an original vendor-provided PPD of a specific device, and you know that an NT4 box (or
any other Windows box) on your LAN has the PostScript driver installed, just use <code class="literal">smbclient
//NT4-box/print\$ -U username</code> to access the Windows directory where all printer driver files are
stored. First look in the <code class="filename">W32X86/2</code> subdirectory for the PPD you are seeking.
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id395604"></a>CUPS Also Uses PPDs for Non-PostScript Printers</h3></div></div></div><p>
<a class="indexterm" name="id395612"></a>
<a class="indexterm" name="id395618"></a>
<a class="indexterm" name="id395625"></a>
CUPS also uses specially crafted PPDs to handle non-PostScript printers. These PPDs are usually not available
from the vendors (and no, you can't just take the PPD of a PostScript printer with the same model name and
hope it works for the non-PostScript version too). To understand how these PPDs work for non-PS printers, we
first need to dive deeply into the CUPS filtering and file format conversion architecture. Stay tuned.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id395639"></a>The CUPS Filtering Architecture</h2></div></div></div><p>
<a class="indexterm" name="id395647"></a>
<a class="indexterm" name="id395653"></a>
<a class="indexterm" name="id395660"></a>
<a class="indexterm" name="id395667"></a>
<a class="indexterm" name="id395674"></a>
The core of the CUPS filtering system is based on Ghostscript. In addition to Ghostscript, CUPS uses some
other filters of its own. You (or your OS vendor) may have plugged in even more filters. CUPS handles all data
file formats under the label of various MIME types. Every incoming print file is subjected to an initial
autotyping. The autotyping determines its given MIME type. A given MIME type implies zero or more possible
filtering chains relevant to the selected target printer. This section discusses how MIME types recognition
and conversion rules interact. They are used by CUPS to automatically set up a working filtering chain for any
given input data format.
</p><p>
If CUPS rasterizes a PostScript file natively to a bitmap, this is done in two stages:
</p><div class="itemizedlist"><ul type="disc"><li><p>
<a class="indexterm" name="id395702"></a>
<a class="indexterm" name="id395709"></a>
The first stage uses a Ghostscript device named “<span class="quote">cups</span>”
(this is since version 1.1.15) and produces a generic raster format
called “<span class="quote">CUPS raster</span>”.
</p></li><li><p>
<a class="indexterm" name="id395729"></a>
The second stage uses a “<span class="quote">raster driver</span>” that converts
the generic CUPS raster to a device-specific raster.
</p></li></ul></div><p>
<a class="indexterm" name="id395744"></a>
<a class="indexterm" name="id395751"></a>
<a class="indexterm" name="id395758"></a>
Make sure your Ghostscript version has the “<span class="quote">cups</span>” device compiled in (check with <code class="literal">gs -h |
grep cups</code>). Otherwise you may encounter the dreaded <code class="computeroutput">Unable to convert file
0</code> in your CUPS error_log file. To have “<span class="quote">cups</span>” as a device in your Ghostscript,
you either need to patch GNU Ghostscript and recompile or use
<a class="indexterm" name="id395786"></a><a href="http://www.cups.org/ghostscript.php" target="_top">ESP Ghostscript</a>. The superior alternative is ESP
Ghostscript. It supports not just CUPS, but 300 other devices (while GNU Ghostscript supports only about 180).
Because of this broad output device support, ESP Ghostscript is the first choice for non-CUPS spoolers, too.
It is now recommended by Linuxprinting.org for all spoolers.
</p><p>
<a class="indexterm" name="id395806"></a>
<a class="indexterm" name="id395812"></a>
<a class="indexterm" name="id395819"></a>
<a class="indexterm" name="id395826"></a>
CUPS printers may be set up to use external rendering paths. One of the most common is provided by the
Foomatic/cupsomatic concept from <a href="http://www.linuxprinting.org/" target="_top">Linuxprinting.org</a>. This
uses the classical Ghostscript approach, doing everything in one step. It does not use the
“<span class="quote">cups</span>” device, but one of the many others. However, even for Foomatic/cupsomatic usage, best
results and <a class="indexterm" name="id395845"></a> broadest printer
model support is provided by ESP Ghostscript (more about Foomatic/cupsomatic, particularly the new version
called now <span class="emphasis"><em>foomatic-rip</em></span>, follows).
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id395860"></a>MIME Types and CUPS Filters</h3></div></div></div><p>
<a class="indexterm" name="id395868"></a>
<a class="indexterm" name="id395878"></a>
<a class="indexterm" name="id395884"></a>
<a class="indexterm" name="id395891"></a>
<a class="indexterm" name="id395898"></a>
CUPS reads the file <code class="filename">/etc/cups/mime.types</code> (and all other files carrying a
<code class="filename">*.types</code> suffix in the same directory) upon startup. These files contain the MIME type
recognition rules that are applied when CUPS runs its autotyping routines. The rule syntax is explained in the
man page for <code class="filename">mime.types</code> and in the comments section of the
<code class="filename">mime.types</code> file itself. A simple rule reads like this:
<a class="indexterm" name="id395931"></a>
</p><pre class="programlisting">
application/pdf pdf string(0,%PDF)
</pre><p>
<a class="indexterm" name="id395944"></a>
<a class="indexterm" name="id395951"></a>
This means if a filename has a <code class="filename">.pdf</code> suffix or if the magic string
<span class="emphasis"><em>%PDF</em></span> is right at the beginning of the file itself (offset 0 from the start), then it is a
PDF file (<em class="parameter"><code>application/pdf</code></em>). Another rule is this:
</p><pre class="programlisting">
application/postscript ai eps ps string(0,%!) string(0,<04>%!)
</pre><p>
<a class="indexterm" name="id395981"></a>
<a class="indexterm" name="id395988"></a>
<a class="indexterm" name="id395995"></a>
<a class="indexterm" name="id396002"></a>
<a class="indexterm" name="id396008"></a>
<a class="indexterm" name="id396015"></a>
If the filename has one of the suffixes <code class="filename">.ai</code>, <code class="filename">.eps</code>,
<code class="filename">.ps</code>, or if the file itself starts with one of the strings <span class="emphasis"><em>%!</em></span> or
<span class="emphasis"><em><04>%!</em></span>, it is a generic PostScript file
(<em class="parameter"><code>application/postscript</code></em>).
</p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
<a class="indexterm" name="id396057"></a>
Don't confuse the other mime.types files your system might be using
with the one in the <code class="filename">/etc/cups/</code> directory.
</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id396075"></a>
<a class="indexterm" name="id396082"></a>
<a class="indexterm" name="id396089"></a>
<a class="indexterm" name="id396095"></a>
<a class="indexterm" name="id396102"></a>
There is an important difference between two similar MIME types in CUPS: one is
<em class="parameter"><code>application/postscript</code></em>, the other is
<em class="parameter"><code>application/vnd.cups-postscript</code></em>. While <em class="parameter"><code>application/postscript</code></em> is
meant to be device-independent, job options for the file are still outside the PS file content, embedded in
command-line or environment variables by CUPS, <em class="parameter"><code>application/vnd.cups-postscript</code></em> may have
the job options inserted into the PostScript data itself (where applicable). The transformation of the generic
PostScript (<em class="parameter"><code>application/postscript</code></em>) to the device-specific version
(<em class="parameter"><code>application/vnd.cups-postscript</code></em>) is the responsibility of the CUPS
<em class="parameter"><code>pstops</code></em> filter. pstops uses information contained in the PPD to do the transformation.
</p></div><p>
<a class="indexterm" name="id396158"></a>
<a class="indexterm" name="id396165"></a>
<a class="indexterm" name="id396172"></a>
<a class="indexterm" name="id396178"></a>
<a class="indexterm" name="id396185"></a>
<a class="indexterm" name="id396192"></a>
<a class="indexterm" name="id396198"></a>
<a class="indexterm" name="id396205"></a>
<a class="indexterm" name="id396211"></a>
<a class="indexterm" name="id396218"></a>
<a class="indexterm" name="id396225"></a>
<a class="indexterm" name="id396232"></a>
<a class="indexterm" name="id396239"></a>
<a class="indexterm" name="id396245"></a>
<a class="indexterm" name="id396252"></a>
<a class="indexterm" name="id396259"></a>
CUPS can handle ASCII text, HP-GL, PDF, PostScript, DVI, and
many image formats (GIF, PNG, TIFF, JPEG, Photo-CD, SUN-Raster,
PNM, PBM, SGI-RGB, and more) and their associated MIME types
with its filters.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id396270"></a>MIME Type Conversion Rules</h3></div></div></div><p>
<a class="indexterm" name="id396278"></a>
<a class="indexterm" name="id396284"></a>
<a class="indexterm" name="id396291"></a>
<a class="indexterm" name="id396298"></a>
<a class="indexterm" name="id396305"></a>
CUPS reads the file <code class="filename">/etc/cups/mime.convs</code>
(and all other files named with a <code class="filename">*.convs</code>
suffix in the same directory) upon startup. These files contain
lines naming an input MIME type, an output MIME type, a format
conversion filter that can produce the output from the input type,
and virtual costs associated with this conversion. One example line
reads like this:
</p><pre class="programlisting">
application/pdf application/postscript 33 pdftops
</pre><p>
<a class="indexterm" name="id396332"></a>
This means that the <em class="parameter"><code>pdftops</code></em> filter will take
<em class="parameter"><code>application/pdf</code></em> as input and produce
<em class="parameter"><code>application/postscript</code></em> as output; the virtual
cost of this operation is 33 CUPS-$. The next filter is more
expensive, costing 66 CUPS-$:
<a class="indexterm" name="id396358"></a>
</p><pre class="programlisting">
application/vnd.hp-HPGL application/postscript 66 hpgltops
</pre><p>
<a class="indexterm" name="id396371"></a>
This is the <em class="parameter"><code>hpgltops</code></em>, which processes HP-GL
plotter files to PostScript.
<a class="indexterm" name="id396384"></a>
</p><pre class="programlisting">
application/octet-stream
</pre><p>
Here are two more examples:
<a class="indexterm" name="id396398"></a>
<a class="indexterm" name="id396404"></a>
<a class="indexterm" name="id396411"></a>
<a class="indexterm" name="id396418"></a>
</p><pre class="programlisting">
application/x-shell application/postscript 33 texttops
text/plain application/postscript 33 texttops
</pre><p>
<a class="indexterm" name="id396431"></a>
The last two examples name the <em class="parameter"><code>texttops</code></em> filter to work on
<em class="parameter"><code>text/plain</code></em> as well as on <em class="parameter"><code>application/x-shell</code></em>. (Hint: This
differentiation is needed for the syntax highlighting feature of <em class="parameter"><code>texttops</code></em>).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id396465"></a>Filtering Overview</h3></div></div></div><p>
<a class="indexterm" name="id396473"></a>
There are many more combinations named in <code class="filename">mime.convs</code>. However, you are not limited to use
the ones predefined there. You can plug in any filter you like to the CUPS framework. It must meet, or must be
made to meet, some minimal requirements. If you find (or write) a cool conversion filter of some kind, make
sure it complies with what CUPS needs and put in the right lines in <code class="filename">mime.types</code> and
<code class="filename">mime.convs</code>; then it will work seamlessly inside CUPS.
</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id396505"></a>Filter Requirements</h4></div></div></div><p>
The “<span class="quote">CUPS requirements</span>” for filters are simple. Take filenames or <code class="filename">stdin</code> as
input and write to <code class="filename">stdout</code>. They should take these arguments:
</p><div class="variablelist"><dl><dt><span class="term">printer</span></dt><dd><p>
The name of the printer queue (normally this is the name of the filter being run).
</p></dd><dt><span class="term">job</span></dt><dd><p>
The numeric job ID for the job being printed.
</p></dd><dt><span class="term">user</span></dt><dd><p>
The string from the originating-user-name attribute.
</p></dd><dt><span class="term">title</span></dt><dd><p>
The string from the job-name attribute.
</p></dd><dt><span class="term">copies</span></dt><dd><p>
The numeric value from the number-copies attribute.
</p></dd><dt><span class="term">options</span></dt><dd><p>
The job options.
</p></dd><dt><span class="term">filename</span></dt><dd><p>
(optionally) The print request file (if missing, filters expected data
fed through <code class="filename">stdin</code>). In most cases, it is easy to
write a simple wrapper script around existing filters to make them work with CUPS.
</p></dd></dl></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id396616"></a>Prefilters</h3></div></div></div><p>
<a class="indexterm" name="id396624"></a>
<a class="indexterm" name="id396631"></a>
<a class="indexterm" name="id396637"></a>
As previously stated, PostScript is the central file format to any UNIX-based
printing system. From PostScript, CUPS generates raster data to feed
non-PostScript printers.
</p><p>
<a class="indexterm" name="id396649"></a>
<a class="indexterm" name="id396656"></a>
<a class="indexterm" name="id396663"></a>
<a class="indexterm" name="id396669"></a>
<a class="indexterm" name="id396676"></a>
<a class="indexterm" name="id396682"></a>
<a class="indexterm" name="id396689"></a>
<a class="indexterm" name="id396696"></a>
<a class="indexterm" name="id396703"></a>
<a class="indexterm" name="id396710"></a>
But what happens if you send one of the supported non-PS formats to print? Then CUPS runs
“<span class="quote">prefilters</span>” on these input formats to generate PostScript first. There are prefilters to create
PostScript from ASCII text, PDF, DVI, or HP-GL. The outcome of these filters is always of MIME type
<em class="parameter"><code>application/postscript</code></em> (meaning that any device-specific print options are not yet
embedded into the PostScript by CUPS and that the next filter to be called is pstops). Another prefilter is
running on all supported image formats, the <em class="parameter"><code>imagetops</code></em> filter. Its outcome is always of
MIME type <em class="parameter"><code>application/vnd.cups-postscript</code></em> (not application/postscript), meaning it has
the print options already embedded into the file. This is shown in <a href="CUPS-printing.html#4small" title="Figure 22.4. Prefiltering in CUPS to Form PostScript.">Prefiltering in
CUPS to Form PostScript</a>.
</p><div class="figure"><a name="4small"></a><p class="title"><b>Figure 22.4. Prefiltering in CUPS to Form PostScript.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/4small.png" width="135" alt="Prefiltering in CUPS to Form PostScript."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id396793"></a>pstops</h3></div></div></div><p>
<a class="indexterm" name="id396801"></a>
<a class="indexterm" name="id396808"></a>
<a class="indexterm" name="id396814"></a>
<a class="indexterm" name="id396821"></a>
<a class="indexterm" name="id396828"></a>
<a class="indexterm" name="id396835"></a>
<a class="indexterm" name="id396842"></a>
<span class="emphasis"><em>pstops</em></span> is a filter that is used to convert <em class="parameter"><code>application/postscript</code></em> to
<em class="parameter"><code>application/vnd.cups-postscript</code></em>. As stated earlier, this filter inserts all
device-specific print options (commands to the printer to ask for the duplexing of output, or stapling and
punching it, and so on) into the PostScript file. An example is illustrated in <a href="CUPS-printing.html#5small" title="Figure 22.5. Adding Device-Specific Print Options.">Adding Device-Specific Print Options</a>.
</p><div class="figure"><a name="5small"></a><p class="title"><b>Figure 22.5. Adding Device-Specific Print Options.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/5small.png" width="135" alt="Adding Device-Specific Print Options."></div></div></div><br class="figure-break"><p>
This is not all. Other tasks performed by it are:
</p><div class="itemizedlist"><ul type="disc"><li><p>
Selecting the range of pages to be printed (e.g., you can choose to
print only pages “<span class="quote">3, 6, 8-11, 16, and 19-21</span>”, or only odd-numbered
pages).
</p></li><li><p>
Putting two or more logical pages on one sheet of paper (the
so-called “<span class="quote">number-up</span>” function).
</p></li><li><p>Counting the pages of the job to insert the accounting
information into the <code class="filename">/var/log/cups/page_log</code>.
</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id396952"></a>pstoraster</h3></div></div></div><p>
<a class="indexterm" name="id396960"></a>
<a class="indexterm" name="id396967"></a>
<a class="indexterm" name="id396973"></a>
<em class="parameter"><code>pstoraster</code></em> is at the core of the CUPS filtering system. It is responsible for the first
stage of the rasterization process. Its input is of MIME type application/vnd.cups-postscript; its output is
application/vnd.cups-raster. This output format is not yet meant to be printable. Its aim is to serve as a
general-purpose input format for more specialized <span class="emphasis"><em>raster drivers</em></span> that are able to
generate device-specific printer data. This is shown in <a href="CUPS-printing.html#cups-raster" title="Figure 22.6. PostScript to Intermediate Raster Format.">the PostScript to
Intermediate Raster Format diagram</a>.
</p><div class="figure"><a name="cups-raster"></a><p class="title"><b>Figure 22.6. PostScript to Intermediate Raster Format.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/6small.png" width="135" alt="PostScript to Intermediate Raster Format."></div></div></div><br class="figure-break"><p>
<a class="indexterm" name="id397044"></a>
<a class="indexterm" name="id397051"></a>
<a class="indexterm" name="id397058"></a>
<a class="indexterm" name="id397065"></a>
CUPS raster is a generic raster format with powerful features. It is able to include per-page information,
color profiles, and more, to be used by the downstream raster drivers. Its MIME type is registered with IANA
and its specification is, of course, completely open. It is designed to make it quite easy and inexpensive for
manufacturers to develop Linux and UNIX raster drivers for their printer models should they choose to do so.
CUPS always takes care of the first stage of rasterization so these vendors do not need to care about
Ghostscript complications (in fact, there are currently more than one vendor financing the development of CUPS
raster drivers). This is illustrated in <a href="CUPS-printing.html#cups-raster2" title="Figure 22.7. CUPS-Raster Production Using Ghostscript.">the CUPS-Raster Production Using
Ghostscript illustration</a>.
</p><div class="figure"><a name="cups-raster2"></a><p class="title"><b>Figure 22.7. CUPS-Raster Production Using Ghostscript.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/7small.png" alt="CUPS-Raster Production Using Ghostscript."></div></div></div><br class="figure-break"><p>
<a class="indexterm" name="id397129"></a>
<a class="indexterm" name="id397136"></a>
<a class="indexterm" name="id397143"></a>
<a class="indexterm" name="id397149"></a>
CUPS versions before version 1.1.15 shipped a binary (or source code) standalone filter, named
<em class="parameter"><code>pstoraster</code></em>. <em class="parameter"><code>pstoraster</code></em>, which was derived from GNU Ghostscript
5.50 and could be installed instead of and in addition to any GNU or AFPL Ghostscript package without
conflicting.
</p><p>
Since version 1.1.15, this feature has changed. The functions for this filter have been integrated back
into Ghostscript (now based on GNU Ghostscript version 7.05). The <em class="parameter"><code>pstoraster</code></em> filter is
now a simple shell script calling <code class="literal">gs</code> with the <code class="literal">-sDEVICE=cups</code> parameter.
If your Ghostscript fails when this command is executed: <code class="literal">gs -h |grep cups</code>, you might not
be able to print, update your Ghostscript.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id397202"></a>imagetops and imagetoraster</h3></div></div></div><p>
<a class="indexterm" name="id397210"></a>
<a class="indexterm" name="id397217"></a>
In the section about prefilters, we mentioned the prefilter
that generates PostScript from image formats. The <em class="parameter"><code>imagetoraster</code></em>
filter is used to convert directly from image to raster, without the
intermediate PostScript stage. It is used more often than the previously
mentioned prefilters. We summarize in a flowchart the image file
filtering in <a href="CUPS-printing.html#small8" title="Figure 22.8. Image Format to CUPS-Raster Format Conversion.">the Image Format to CUPS-Raster Format Conversion illustration</a>.
</p><div class="figure"><a name="small8"></a><p class="title"><b>Figure 22.8. Image Format to CUPS-Raster Format Conversion.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/8small.png" alt="Image Format to CUPS-Raster Format Conversion."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id397282"></a>rasterto [printers specific]</h3></div></div></div><p>
<a class="indexterm" name="id397290"></a>
<a class="indexterm" name="id397297"></a>
<a class="indexterm" name="id397304"></a>
<a class="indexterm" name="id397310"></a>
<a class="indexterm" name="id397317"></a>
<a class="indexterm" name="id397324"></a>
<a class="indexterm" name="id397331"></a>
<a class="indexterm" name="id397338"></a>
<a class="indexterm" name="id397344"></a>
<a class="indexterm" name="id397351"></a>
<a class="indexterm" name="id397358"></a>
CUPS ships with quite a variety of raster drivers for processing CUPS raster. On my system, I find in
/usr/lib/cups/filter/ the following: <em class="parameter"><code>rastertoalps</code></em>, <em class="parameter"><code>rastertobj</code></em>,
<em class="parameter"><code>rastertoepson</code></em>, <em class="parameter"><code>rastertoescp</code></em>, <em class="parameter"><code>rastertopcl</code></em>,
<em class="parameter"><code>rastertoturboprint</code></em>, <em class="parameter"><code>rastertoapdk</code></em>,
<em class="parameter"><code>rastertodymo</code></em>, <em class="parameter"><code>rastertoescp</code></em>, <em class="parameter"><code>rastertohp</code></em>,
and <em class="parameter"><code>rastertoprinter</code></em>. Don't worry if you have fewer drivers than this; some of these are
installed by commercial add-ons to CUPS (like <em class="parameter"><code>rastertoturboprint</code></em>), and others (like
<em class="parameter"><code>rastertoprinter</code></em>) by third-party driver development projects (such as Gimp-Print)
wanting to cooperate as closely as possible with CUPS. See <a href="CUPS-printing.html#small9" title="Figure 22.9. Raster to Printer-Specific Formats.">the Raster to
Printer-Specific Formats illustration</a>.
</p><div class="figure"><a name="small9"></a><p class="title"><b>Figure 22.9. Raster to Printer-Specific Formats.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/9small.png" alt="Raster to Printer-Specific Formats."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id397494"></a>CUPS Backends</h3></div></div></div><p>
<a class="indexterm" name="id397502"></a>
<a class="indexterm" name="id397509"></a>
The last part of any CUPS filtering chain is a backend. Backends
are special programs that send the print-ready file to the final
device. There is a separate backend program for any transfer
protocol for sending print jobs over the network, and one for every local
interface. Every CUPS print queue needs to have a CUPS “<span class="quote">device-URI</span>”
associated with it. The device URI is the way to encode the backend
used to send the job to its destination. Network device-URIs use
two slashes in their syntax, local device URIs only one, as you can
see from the following list. Keep in mind that local interface names
may vary greatly from my examples, if your OS is not Linux:
</p><div class="variablelist"><dl><dt><span class="term">usb</span></dt><dd><p>
This backend sends print files to USB-connected printers. An
example for the CUPS device-URI to use is
<code class="filename">usb:/dev/usb/lp0</code>.
</p></dd><dt><span class="term">serial</span></dt><dd><p>
This backend sends print files to serially connected printers.
An example for the CUPS device-URI to use is
<code class="filename">serial:/dev/ttyS0?baud=11500</code>.
</p></dd><dt><span class="term">parallel</span></dt><dd><p>
This backend sends print files to printers connected to the
parallel port. An example for the CUPS device-URI to use is
<code class="filename">parallel:/dev/lp0</code>.
</p></dd><dt><span class="term">SCSI</span></dt><dd><p>
This backend sends print files to printers attached to the
SCSI interface. An example for the CUPS device-URI to use is
<code class="filename">scsi:/dev/sr1</code>.
</p></dd><dt><span class="term">lpd</span></dt><dd><p>
This backend sends print files to LPR/LPD-connected network
printers. An example for the CUPS device-URI to use is
<code class="filename">lpd://remote_host_name/remote_queue_name</code>.
</p></dd><dt><span class="term">AppSocket/HP JetDirect</span></dt><dd><p>
This backend sends print files to AppSocket (a.k.a., HP
JetDirect) connected network printers. An example for the CUPS
device-URI to use is
<code class="filename">socket://10.11.12.13:9100</code>.
</p></dd><dt><span class="term">ipp</span></dt><dd><p>
This backend sends print files to IPP-connected network
printers (or to other CUPS servers). Examples for CUPS device-URIs
to use are
<code class="filename">ipp:://192.193.194.195/ipp</code>
(for many HP printers) and
<code class="filename">ipp://remote_cups_server/printers/remote_printer_name</code>.
</p></dd><dt><span class="term">http</span></dt><dd><p>
This backend sends print files to HTTP-connected printers.
(The http:// CUPS backend is only a symlink to the ipp:// backend.)
Examples for the CUPS device-URIs to use are
<code class="filename">http:://192.193.194.195:631/ipp</code>
(for many HP printers) and
<code class="filename">http://remote_cups_server:631/printers/remote_printer_name</code>.
</p></dd><dt><span class="term">smb</span></dt><dd><p>
This backend sends print files to printers shared by a Windows
host. Examples of CUPS device-URIs that may be used includes:
</p><p>
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><code class="filename">smb://workgroup/server/printersharename</code></td></tr><tr><td><code class="filename">smb://server/printersharename</code></td></tr><tr><td><code class="filename">smb://username:password@workgroup/server/printersharename</code></td></tr><tr><td><code class="filename">smb://username:password@server/printersharename</code></td></tr></table><p>
</p><p>
The smb:// backend is a symlink to the Samba utility
<em class="parameter"><code>smbspool</code></em> (does not ship with CUPS). If the
symlink is not present in your CUPS backend directory, have your
root user create it: <code class="literal">ln -s `which smbspool'
/usr/lib/cups/backend/smb</code>.
</p></dd></dl></div><p>
It is easy to write your own backends as shell or Perl scripts if you
need any modification or extension to the CUPS print system. One
reason could be that you want to create “<span class="quote">special</span>” printers that send
the print jobs as email (through a “<span class="quote">mailto:/</span>” backend), convert them to
PDF (through a “<span class="quote">pdfgen:/</span>” backend) or dump them to “<span class="quote">/dev/null</span>”. (In
fact, I have the systemwide default printer set up to be connected to
a devnull:/ backend: there are just too many people sending jobs
without specifying a printer, and scripts and programs that do not name
a printer. The systemwide default deletes the job and sends a polite
email back to the $USER asking him or her to always specify the correct
printer name.)
</p><p>
<a class="indexterm" name="id397760"></a>
<a class="indexterm" name="id397767"></a>
Not all of the mentioned backends may be present on your system or
usable (depending on your hardware configuration). One test for all
available CUPS backends is provided by the <span class="emphasis"><em>lpinfo</em></span>
utility. Used with the <code class="option">-v</code> parameter, it lists
all available backends:
</p><pre class="screen">
<code class="prompt">$ </code><strong class="userinput"><code>lpinfo -v</code></strong>
</pre></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id397802"></a>The Role of <em class="parameter"><code>cupsomatic/foomatic</code></em></h3></div></div></div><p>
<a class="indexterm" name="id397814"></a>
<a class="indexterm" name="id397821"></a>
<a class="indexterm" name="id397828"></a>
<a class="indexterm" name="id397835"></a>
<a class="indexterm" name="id397842"></a>
<em class="parameter"><code>cupsomatic</code></em> filters may be the most widely used on CUPS
installations. You must be clear that these were not
developed by the CUPS people. They are a third-party add-on to
CUPS. They utilize the traditional Ghostscript devices to render jobs
for CUPS. When troubleshooting, you should know about the
difference. Here the whole rendering process is done in one stage,
inside Ghostscript, using an appropriate device for the target
printer. <em class="parameter"><code>cupsomatic</code></em> uses PPDs that are generated from the Foomatic
Printer & Driver Database at Linuxprinting.org.
</p><p>
You can recognize these PPDs from the line calling the
<em class="parameter"><code>cupsomatic</code></em> filter:
</p><pre class="programlisting">
*cupsFilter: "application/vnd.cups-postscript 0 cupsomatic"
</pre><p>
You may find this line among the first 40 or so lines of the PPD
file. If you have such a PPD installed, the printer shows up in the
CUPS Web interface with a <em class="parameter"><code>foomatic</code></em> namepart for
the driver description. <em class="parameter"><code>cupsomatic</code></em> is a Perl script that runs
Ghostscript with all the complicated command-line options
autoconstructed from the selected PPD and command line options give to
the print job.
</p><p>
<a class="indexterm" name="id397899"></a>
<a class="indexterm" name="id397906"></a>
<a class="indexterm" name="id397912"></a>
<a class="indexterm" name="id397919"></a>
<a class="indexterm" name="id397926"></a>
<a class="indexterm" name="id397933"></a>
<a class="indexterm" name="id397940"></a>
<a class="indexterm" name="id397946"></a>
<a class="indexterm" name="id397953"></a>
<a class="indexterm" name="id397960"></a>
<a class="indexterm" name="id397967"></a>
However, <em class="parameter"><code>cupsomatic</code></em> is now deprecated. Its PPDs (especially the first
generation of them, still in heavy use out there) are not meeting the
Adobe specifications. You might also suffer difficulties when you try
to download them with “<span class="quote">Point'n'Print</span>” to Windows clients. A better
and more powerful successor is now in a stable beta-version: it is called <em class="parameter"><code>foomatic-rip</code></em>. To use
<em class="parameter"><code>foomatic-rip</code></em> as a filter with CUPS, you need the new type of PPDs, which
have a similar but different line:
</p><pre class="programlisting">
*cupsFilter: "application/vnd.cups-postscript 0 foomatic-rip"
</pre><p>
The PPD-generating engine at Linuxprinting.org has been revamped.
The new PPDs comply with the Adobe spec. They also provide a
new way to specify different quality levels (hi-res photo, normal
color, grayscale, and draft) with a single click, whereas before you
could have required five or more different selections (media type,
resolution, inktype, and dithering algorithm). There is support for
custom-size media built in. There is support to switch
print options from page to page in the middle of a job. And the
best thing is that the new <code class="constant">foomatic-rip</code> works seamlessly with all
legacy spoolers too (like LPRng, BSD-LPD, PDQ, PPR, and so on), providing
for them access to use PPDs for their printing.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id398021"></a>The Complete Picture</h3></div></div></div><p>
If you want to see an overview of all the filters and how they
relate to each other, the complete picture of the puzzle is at the end
of this chapter.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id398033"></a><code class="filename">mime.convs</code></h3></div></div></div><p>
CUPS autoconstructs all possible filtering chain paths for any given
MIME type and every printer installed. But how does it decide in
favor of or against a specific alternative? (There may be cases
where there is a choice of two or more possible filtering chains for
the same target printer.) Simple. You may have noticed the figures in
the third column of the mime.convs file. They represent virtual costs
assigned to this filter. Every possible filtering chain will sum up to
a total “<span class="quote">filter cost.</span>” CUPS decides for the most “<span class="quote">inexpensive</span>” route.
</p><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3><p>
<a class="indexterm" name="id398060"></a>
<a class="indexterm" name="id398067"></a>
Setting <em class="parameter"><code>FilterLimit 1000</code></em> in
<code class="filename">cupsd.conf</code> will not allow more filters to
run concurrently than will consume a total of 1000 virtual filter
cost. This is an efficient way to limit the load of any CUPS
server by setting an appropriate “<span class="quote">FilterLimit</span>” value. A FilterLimit of
200 allows roughly one job at a time, while a FilterLimit of 1000 allows
approximately five jobs maximum at a time.
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id398094"></a>“<span class="quote">Raw</span>” Printing</h3></div></div></div><p>
<a class="indexterm" name="id398104"></a>
<a class="indexterm" name="id398111"></a>
<a class="indexterm" name="id398117"></a>
You can tell CUPS to print (nearly) any file “<span class="quote">raw</span>”. “<span class="quote">Raw</span>” means it will not be
filtered. CUPS will send the file to the printer “<span class="quote">as is</span>” without bothering if the printer is able
to digest it. Users need to take care themselves that they send sensible data formats only. Raw printing can
happen on any queue if the “<span class="quote"><em class="parameter"><code>-o raw</code></em></span>” option is specified on the command
line. You can also set up raw-only queues by simply not associating any PPD with it. This command:
</p><pre class="screen">
<code class="prompt">$ </code><strong class="userinput"><code>lpadmin -P rawprinter -v socket://11.12.13.14:9100 -E</code></strong>
</pre><p>
sets up a queue named “<span class="quote">rawprinter</span>”, connected via the “<span class="quote">socket</span>” protocol (a.k.a.
“<span class="quote">HP JetDirect</span>”) to the device at IP address 11.12.1.3.14, using port 9100. (If you had added a
PPD with <code class="literal">-P /path/to/PPD</code> to this command line, you would have installed a
“<span class="quote">normal</span>” print queue.)
</p><p>
CUPS will automatically treat each job sent to a queue as a “<span class="quote">raw</span>” one
if it can't find a PPD associated with the queue. However, CUPS will
only send known MIME types (as defined in its own mime.types file) and
refuse others.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id398194"></a>application/octet-stream Printing</h3></div></div></div><p>
<a class="indexterm" name="id398202"></a>
<a class="indexterm" name="id398209"></a>
Any MIME type with no rule in the <code class="filename">/etc/cups/mime.types</code> file is regarded as unknown
or <em class="parameter"><code>application/octet-stream</code></em> and will not be
sent. Because CUPS refuses to print unknown MIME types by default,
you will probably have experienced that print jobs originating
from Windows clients were not printed. You may have found an error
message in your CUPS logs like:
</p><p><code class="computeroutput">
Unable to convert file 0 to printable format for job
</code></p><p>
To enable the printing of <em class="parameter"><code>application/octet-stream</code></em> files, edit
these two files:
</p><div class="itemizedlist"><ul type="disc"><li><p><code class="filename">/etc/cups/mime.convs</code></p></li><li><p><code class="filename">/etc/cups/mime.types</code></p></li></ul></div><p>
<a class="indexterm" name="id398269"></a>
Both contain entries (at the end of the respective files) that must be uncommented to allow raw mode
operation for <em class="parameter"><code>application/octet-stream</code></em>. In <code class="filename">/etc/cups/mime.types</code>
make sure this line is present:
<a class="indexterm" name="id398290"></a>
</p><pre class="programlisting">
application/octet-stream
</pre><p>
This line (with no specific autotyping rule set) makes all files
not otherwise auto-typed a member of <em class="parameter"><code>application/octet-stream</code></em>. In
<code class="filename">/etc/cups/mime.convs</code>, have this
line:
</p><pre class="programlisting">
application/octet-stream application/vnd.cups-raw 0 -
</pre><p>
<a class="indexterm" name="id398322"></a>
This line tells CUPS to use the <span class="emphasis"><em>Null Filter</em></span>
(denoted as “<span class="quote">-</span>”, doing nothing at all) on
<em class="parameter"><code>application/octet-stream</code></em>, and tag the result as
<em class="parameter"><code>application/vnd.cups-raw</code></em>. This last one is
always a green light to the CUPS scheduler to now hand the file over
to the backend connecting to the printer and sending it over.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
Editing the <code class="filename">mime.convs</code> and the <code class="filename">mime.types</code> file does not
<span class="emphasis"><em>enforce</em></span> “<span class="quote">raw</span>” printing, it only <span class="emphasis"><em>allows</em></span> it.
</p></div><p><b>Background. </b>
<a class="indexterm" name="id398386"></a>
<a class="indexterm" name="id398393"></a>
<a class="indexterm" name="id398399"></a>
<a class="indexterm" name="id398406"></a>
That CUPS is a more security-aware printing system than traditional ones
does not by default allow one to send deliberate (possibly binary)
data to printing devices. (This could be easily abused to launch a
Denial of Service attack on your printer(s), causing at least the loss
of a lot of paper and ink.) “<span class="quote">Unknown</span>” data are regarded by CUPS
as <span class="emphasis"><em>MIME type</em></span> <span class="emphasis"><em>application/octet-stream</em></span>. While you
<span class="emphasis"><em>can</em></span> send data “<span class="quote">raw</span>”, the MIME type for these must
be one that is known to CUPS and allowed by it. The file
<code class="filename">/etc/cups/mime.types</code> defines the “<span class="quote">rules</span>” of how CUPS
recognizes MIME types. The file <code class="filename">/etc/cups/mime.convs</code> decides which file
conversion filter(s) may be applied to which MIME types.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id398455"></a>PostScript Printer Descriptions for Non-PostScript Printers</h3></div></div></div><p>
<a class="indexterm" name="id398463"></a>
<a class="indexterm" name="id398469"></a>
<a class="indexterm" name="id398476"></a>
<a class="indexterm" name="id398483"></a>
<a class="indexterm" name="id398489"></a>
<a class="indexterm" name="id398496"></a>
Originally PPDs were meant to be used for PostScript printers
only. Here, they help to send device-specific commands and settings
to the RIP, which processes the job file. CUPS has extended this
scope for PPDs to cover non-PostScript printers too. This was not
difficult, because it is a standardized file format. In a way
it was logical too: CUPS handles PostScript and uses a PostScript
RIP (Ghostscript) to process the job files. The only difference is that
a PostScript printer has the RIP built-in, for other types of
printers the Ghostscript RIP runs on the host computer.
</p><p>
PPDs for a non-PostScript printer have a few lines that are unique to
CUPS. The most important one looks similar to this:
<a class="indexterm" name="id398513"></a>
</p><pre class="programlisting">
*cupsFilter: application/vnd.cups-raster 66 rastertoprinter
</pre><p>
It is the last piece in the CUPS filtering puzzle. This line tells the
CUPS daemon to use as a last filter <em class="parameter"><code>rastertoprinter</code></em>. This filter
should be served as input an <em class="parameter"><code>application/vnd.cups-raster</code></em> MIME type
file. Therefore, CUPS should autoconstruct a filtering chain, which
delivers as its last output the specified MIME type. This is then
taken as input to the specified <em class="parameter"><code>rastertoprinter</code></em> filter. After
the last filter has done its work (<em class="parameter"><code>rastertoprinter</code></em> is a Gimp-Print
filter), the file should go to the backend, which sends it to the
output device.
</p><p>
CUPS by default ships only a few generic PPDs, but they are good for
several hundred printer models. You may not be able to control
different paper trays, or you may get larger margins than your
specific model supports. See Table 21.1<a href="CUPS-printing.html#cups-ppds" title="Table 22.1. PPDs Shipped with CUPS">???</a> for summary information.
</p><div class="table"><a name="cups-ppds"></a><p class="title"><b>Table 22.1. PPDs Shipped with CUPS</b></p><div class="table-contents"><table summary="PPDs Shipped with CUPS" border="1"><colgroup><col align="left"><col align="justify"></colgroup><thead><tr><th align="left">PPD file</th><th align="justify">Printer type</th></tr></thead><tbody><tr><td align="left">deskjet.ppd</td><td align="justify">older HP inkjet printers and compatible</td></tr><tr><td align="left">deskjet2.ppd</td><td align="justify">newer HP inkjet printers and compatible </td></tr><tr><td align="left">dymo.ppd</td><td align="justify">label printers </td></tr><tr><td align="left">epson9.ppd</td><td align="justify">Epson 24-pin impact printers and compatible </td></tr><tr><td align="left">epson24.ppd</td><td align="justify">Epson 24-pin impact printers and compatible </td></tr><tr><td align="left">okidata9.ppd</td><td align="justify">Okidata 9-pin impact printers and compatible </td></tr><tr><td align="left">okidat24.ppd</td><td align="justify">Okidata 24-pin impact printers and compatible </td></tr><tr><td align="left">stcolor.ppd</td><td align="justify">older Epson Stylus Color printers </td></tr><tr><td align="left">stcolor2.ppd</td><td align="justify">newer Epson Stylus Color printers </td></tr><tr><td align="left">stphoto.ppd</td><td align="justify">older Epson Stylus Photo printers </td></tr><tr><td align="left">stphoto2.ppd</td><td align="justify">newer Epson Stylus Photo printers </td></tr><tr><td align="left">laserjet.ppd</td><td align="justify">all PCL printers </td></tr></tbody></table></div></div><br class="table-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id398718"></a><span class="emphasis"><em>cupsomatic/foomatic-rip</em></span> Versus <span class="emphasis"><em>Native CUPS</em></span> Printing</h3></div></div></div><p>
<a class="indexterm" name="id398732"></a>
<a class="indexterm" name="id398739"></a>
Native CUPS rasterization works in two steps:
</p><div class="itemizedlist"><ul type="disc"><li><p>
<a class="indexterm" name="id398753"></a>
First is the <em class="parameter"><code>pstoraster</code></em> step. It uses the special CUPS
<a class="indexterm" name="id398766"></a>
device from ESP Ghostscript 7.05.x as its tool.
</p></li><li><p>
Second is the <em class="parameter"><code>rasterdriver</code></em> step. It uses various
device-specific filters; there are several vendors who provide good
quality filters for this step. Some are free software, some are
shareware, and some are proprietary.
</p></li></ul></div><p>
Often this produces better quality (and has several more advantages) than other methods.
This is shown in <a href="CUPS-printing.html#cupsomatic-dia" title="Figure 22.10. cupsomatic/foomatic Processing Versus Native CUPS."> the cupsomatic/foomatic Processing Versus Native CUPS
illustration</a>.
</p><div class="figure"><a name="cupsomatic-dia"></a><p class="title"><b>Figure 22.10. cupsomatic/foomatic Processing Versus Native CUPS.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/10small.png" alt="cupsomatic/foomatic Processing Versus Native CUPS."></div></div></div><br class="figure-break"><p>
One other method is the <em class="parameter"><code>cupsomatic/foomatic-rip</code></em>
way. Note that <em class="parameter"><code>cupsomatic</code></em> is <span class="emphasis"><em>not</em></span> made by the CUPS
developers. It is an independent contribution to printing development,
made by people from Linuxprinting.org.<sup>[<a name="id398861" href="#ftn.id398861">6</a>]</sup>
<em class="parameter"><code>cupsomatic</code></em> is no longer developed, maintained, or supported. It now been
replaced by <em class="parameter"><code>foomatic-rip</code></em>. <em class="parameter"><code>foomatic-rip</code></em> is a complete rewrite
of the old <em class="parameter"><code>cupsomatic</code></em> idea, but very much improved and generalized to
other (non-CUPS) spoolers. An upgrade to <em class="parameter"><code>foomatic-rip</code></em> is strongly
advised, especially if you are upgrading to a recent version of CUPS,
too.
</p><p>
<a class="indexterm" name="id398907"></a>
<a class="indexterm" name="id398914"></a>
Like the old <em class="parameter"><code>cupsomatic</code></em> method, the <em class="parameter"><code>foomatic-rip</code></em> (new) method
from Linuxprinting.org uses the traditional Ghostscript print file processing, doing everything in a single
step. It therefore relies on all the other devices built into Ghostscript. The quality is as good (or bad) as
Ghostscript rendering is in other spoolers. The advantage is that this method supports many printer models not
supported (yet) by the more modern CUPS method.
</p><p>
Of course, you can use both methods side by side on one system (and even for one printer, if you set up
different queues) and find out which works best for you.
</p><p>
<a class="indexterm" name="id398944"></a>
<a class="indexterm" name="id398951"></a>
<a class="indexterm" name="id398958"></a>
<a class="indexterm" name="id398964"></a>
<a class="indexterm" name="id398971"></a>
<a class="indexterm" name="id398978"></a>
<em class="parameter"><code>cupsomatic</code></em> kidnaps the print file after the
<em class="parameter"><code>application/vnd.cups-postscript</code></em> stage and deviates it through the CUPS-external,
systemwide Ghostscript installation. Therefore, the print file bypasses the <em class="parameter"><code>pstoraster</code></em>
filter (and also bypasses the CUPS raster drivers <em class="parameter"><code>rastertosomething</code></em>). After Ghostscript
finished its rasterization, <em class="parameter"><code>cupsomatic</code></em> hands the rendered file directly to the CUPS
backend. <a href="CUPS-printing.html#cupsomatic-dia" title="Figure 22.10. cupsomatic/foomatic Processing Versus Native CUPS.">cupsomatic/foomatic Processing Versus Native
CUPS</a>, illustrates the difference between native CUPS rendering and the
<em class="parameter"><code>Foomatic/cupsomatic</code></em> method.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id399033"></a>Examples for Filtering Chains</h3></div></div></div><p>
Here are a few examples of commonly occurring filtering chains to
illustrate the workings of CUPS.
</p><p>
<a class="indexterm" name="id399045"></a>
<a class="indexterm" name="id399052"></a>
<a class="indexterm" name="id399058"></a>
<a class="indexterm" name="id399065"></a>
Assume you want to print a PDF file to an HP JetDirect-connected
PostScript printer, but you want to print pages 3-5, 7, and 11-13
only, and you want to print them “<span class="quote">two-up</span>” and “<span class="quote">duplex</span>”:
</p><div class="itemizedlist"><ul type="disc"><li><p>Your print options (page selection as required, two-up,
duplex) are passed to CUPS on the command line.</p></li><li><p>The (complete) PDF file is sent to CUPS and autotyped as
<em class="parameter"><code>application/pdf</code></em>.</p></li><li><p>The file therefore must first pass the
<em class="parameter"><code>pdftops</code></em> prefilter, which produces PostScript
MIME type <em class="parameter"><code>application/postscript</code></em> (a preview here
would still show all pages of the original PDF).</p></li><li><p>The file then passes the <em class="parameter"><code>pstops</code></em>
filter that applies the command-line options: it selects pages
2-5, 7, and 11-13, creates the imposed layout “<span class="quote">two pages on one sheet</span>”, and
inserts the correct “<span class="quote">duplex</span>” command (as defined in the printer's
PPD) into the new PostScript file; the file is now of PostScript MIME
type
<em class="parameter"><code>application/vnd.cups-postscript</code></em>.</p></li><li><p>The file goes to the <em class="parameter"><code>socket</code></em>
backend, which transfers the job to the printers.</p></li></ul></div><p>
The resulting filter chain, therefore, is as shown in <a href="CUPS-printing.html#pdftosocket" title="Figure 22.11. PDF to Socket Chain.">the PDF to socket chain
illustration</a>.
</p><a class="indexterm" name="id399167"></a><div class="figure"><a name="pdftosocket"></a><p class="title"><b>Figure 22.11. PDF to Socket Chain.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/pdftosocket.png" alt="PDF to Socket Chain."></div></div></div><br class="figure-break"><p>
<a class="indexterm" name="id399215"></a>
<a class="indexterm" name="id399222"></a>
<a class="indexterm" name="id399229"></a>
Assume you want to print the same filter to an USB-connected Epson Stylus Photo Printer installed with the CUPS
<code class="filename">stphoto2.ppd</code>. The first few filtering stages are nearly the same:
</p><div class="itemizedlist"><ul type="disc"><li><p>
Your print options (page selection as required, two-up,
duplex) are passed to CUPS on the command line.
</p></li><li><p>
The (complete) PDF file is sent to CUPS and autotyped as
<em class="parameter"><code>application/pdf</code></em>.
</p></li><li><p>
<a class="indexterm" name="id399266"></a>
<a class="indexterm" name="id399272"></a>
The file must first pass the <em class="parameter"><code>pdftops</code></em> prefilter, which produces PostScript
MIME type <em class="parameter"><code>application/postscript</code></em> (a preview here would still show all
pages of the original PDF).
</p></li><li><p>
<a class="indexterm" name="id399296"></a>
<a class="indexterm" name="id399303"></a>
The file then passes the “<span class="quote">pstops</span>” filter that applies
the command-line options: it selects the pages 2-5, 7, and 11-13,
creates the imposed layout “<span class="quote">two pages on one sheet,</span>” and inserts the
correct “<span class="quote">duplex</span>” command (oops this printer and PPD
do not support duplex printing at all, so this option will
be ignored) into the new PostScript file; the file is now of PostScript
MIME type <em class="parameter"><code>application/vnd.cups-postscript</code></em>.
</p></li><li><p>
The file then passes the <em class="parameter"><code>pstoraster</code></em> stage and becomes MIME type
<em class="parameter"><code>application/cups-raster</code></em>.
</p></li><li><p>
<a class="indexterm" name="id399354"></a>
Finally, the <em class="parameter"><code>rastertoepson</code></em> filter
does its work (as indicated in the printer's PPD), creating the
printer-specific raster data and embedding any user-selected
print options into the print data stream.
</p></li><li><p>
The file goes to the <em class="parameter"><code>usb</code></em> backend, which transfers the job to the printers.
</p></li></ul></div><p>
The resulting filter chain therefore is as shown in <a href="CUPS-printing.html#pdftoepsonusb" title="Figure 22.12. PDF to USB Chain.">the PDF to USB Chain
illustration</a>.
</p><div class="figure"><a name="pdftoepsonusb"></a><p class="title"><b>Figure 22.12. PDF to USB Chain.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/pdftoepsonusb.png" alt="PDF to USB Chain."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id399434"></a>Sources of CUPS Drivers/PPDs</h3></div></div></div><p>
On the Internet you can now find many thousands of CUPS-PPD files
(with their companion filters), in many national languages
supporting more than 1,000 non-PostScript models.
</p><div class="itemizedlist"><a class="indexterm" name="id399447"></a><a class="indexterm" name="id399456"></a><ul type="disc"><li><p>
<a href="http://www.easysw.com/printpro/" target="_top">ESP PrintPro</a>
(commercial, non-free) is packaged with more than 3,000 PPDs, ready for
successful use “<span class="quote">out of the box</span>” on Linux, Mac OS X, IBM-AIX,
HP-UX, Sun-Solaris, SGI-IRIX, Compaq Tru64, Digital UNIX, and
other commercial Unices (it is written by the CUPS developers
themselves and its sales help finance the further development of
CUPS, as they feed their creators).
</p></li><li><p>
The <a href="http://gimp-print.sourceforge.net/" target="_top">Gimp-Print Project</a>
(GPL, free software) provides around 140 PPDs (supporting nearly 400 printers, many driven
to photo quality output), to be used alongside the Gimp-Print CUPS filters.
</p></li><li><p>
<a href="http://www.turboprint.de/english.html/" target="_top">TurboPrint </a> (shareware, non-free) supports
roughly the same number of printers in excellent quality.
</p></li><li><p>
<a href="http://www-124.ibm.com/developerworks/oss/linux/projects/omni/" target="_top">OMNI </a>
(LPGL, free) is a package made by IBM, now containing support for more
than 400 printers, stemming from the inheritance of IBM OS/2 know-how
ported over to Linux (CUPS support is in a beta stage at present).
</p></li><li><p>
<a href="http://hpinkjet.sourceforge.net/" target="_top">HPIJS </a> (BSD-style licenses, free)
supports approximately 150 of HP's own printers and also provides
excellent print quality now (currently available only via the Foomatic path).
</p></li><li><p>
<a href="http://www.linuxprinting.org/" target="_top">Foomatic/cupsomatic </a>
(LPGL, free) from Linuxprinting.org provide PPDs for practically every Ghostscript
filter known to the world (including Omni, Gimp-Print, and HPIJS).
</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id399543"></a>Printing with Interface Scripts</h3></div></div></div><p>
<a class="indexterm" name="id399551"></a>
<a class="indexterm" name="id399557"></a>
CUPS also supports the use of “<span class="quote">interface scripts</span>” as known from
System V AT&T printing systems. These are often used for PCL
printers, from applications that generate PCL print jobs. Interface
scripts are specific to printer models. They have a role similar to
PPDs for PostScript printers. Interface scripts may inject the Escape
sequences as required into the print data stream if the user, for example, selects
a certain paper tray, or changes paper orientation, or uses A3
paper. Interface scripts are practically unknown in the Linux
realm. On HP-UX platforms they are more often used. You can use any
working interface script on CUPS too. Just install the printer with
the <code class="literal">-i</code> option:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>lpadmin -p pclprinter -v socket://11.12.13.14:9100 \
-i /path/to/interface-script</code></strong>
</pre><p>
Interface scripts might be the “<span class="quote">unknown animal</span>” to many. However,
with CUPS they provide the easiest way to plug in your own custom-written filtering
script or program into one specific print queue (some information about the traditional
use of interface scripts is found at
<a href="http://playground.sun.com/printing/documentation/interface.html" target="_top">
http://playground.sun.com/printing/documentation/interface.html</a>).
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id399622"></a>Network Printing (Purely Windows)</h2></div></div></div><p>
Network printing covers a lot of ground. To understand what exactly
goes on with Samba when it is printing on behalf of its Windows
clients, let's first look at a “<span class="quote">purely Windows</span>” setup: Windows clients
with a Windows NT print server.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id399636"></a>From Windows Clients to an NT Print Server</h3></div></div></div><p>
Windows clients printing to an NT-based print server have two
options. They may:
<a class="indexterm" name="id399645"></a>
<a class="indexterm" name="id399652"></a>
</p><div class="itemizedlist"><ul type="disc"><li><p>Execute the driver locally and render the GDI output
(EMF) into the printer-specific format on their own.
</p></li><li><p>Send the GDI output (EMF) to the server, where the
driver is executed to render the printer-specific output.
</p></li></ul></div><p>
Both print paths are shown in the flowcharts in <a href="CUPS-printing.html#small11" title="Figure 22.13. Print Driver Execution on the Client.">
Print Driver Execution on the Client</a>, and
<a href="CUPS-printing.html#small12" title="Figure 22.14. Print Driver Execution on the Server.">Print Driver Execution on the Server</a>.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id399694"></a>Driver Execution on the Client</h3></div></div></div><p>
In the first case, the print server must spool the file as raw, meaning it shouldn't touch the job file and try
to convert it in any way. This is what a traditional UNIX-based print server can do too, and at a better
performance and more reliably than an NT print server. This is what most Samba administrators probably are
familiar with. One advantage of this setup is that this “<span class="quote">spooling-only</span>” print server may be used
even if no driver(s) for UNIX is available. It is sufficient to have the Windows client drivers available and
installed on the clients. This is illustrated in <a href="CUPS-printing.html#small11" title="Figure 22.13. Print Driver Execution on the Client.">the Print Driver Execution on the
Client diagram</a>.
</p><div class="figure"><a name="small11"></a><p class="title"><b>Figure 22.13. Print Driver Execution on the Client.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/11small.png" alt="Print Driver Execution on the Client."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id399759"></a>Driver Execution on the Server</h3></div></div></div><p>
<a class="indexterm" name="id399767"></a>
<a class="indexterm" name="id399774"></a>
<a class="indexterm" name="id399780"></a>
<a class="indexterm" name="id399787"></a>
<a class="indexterm" name="id399794"></a>
The other path executes the printer driver on the server. The client transfers print files in EMF format to
the server. The server uses the PostScript, PCL, ESC/P, or other driver to convert the EMF file into the
printer-specific language. It is not possible for UNIX to do the same. Currently, there is no program or
method to convert a Windows client's GDI output on a UNIX server into something a printer could understand.
This is illustrated in <a href="CUPS-printing.html#small12" title="Figure 22.14. Print Driver Execution on the Server.">the Print Driver Execution on the Server diagram</a>.
</p><div class="figure"><a name="small12"></a><p class="title"><b>Figure 22.14. Print Driver Execution on the Server.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/12small.png" alt="Print Driver Execution on the Server."></div></div></div><br class="figure-break"><p>
However, something similar is possible with CUPS, so read on.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id399858"></a>Network Printing (Windows Clients and UNIX/Samba Print
Servers)</h2></div></div></div><p>
Since UNIX print servers <span class="emphasis"><em>cannot</em></span> execute the Win32
program code on their platform, the picture is somewhat
different. However, this does not limit your options all that
much. On the contrary, you may have a way here to implement printing
features that are not possible otherwise.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id399874"></a>From Windows Clients to a CUPS/Samba Print Server</h3></div></div></div><p>
Here is a simple recipe showing how you can take advantage of CUPS's
powerful features for the benefit of your Windows network printing
clients:
</p><div class="itemizedlist"><ul type="disc"><li><p>Let the Windows clients send PostScript to the CUPS
server.</p></li><li><p>Let the CUPS server render the PostScript into device-specific raster format.</p></li></ul></div><p>
This requires the clients to use a PostScript driver (even if the
printer is a non-PostScript model. It also requires that you have a
driver on the CUPS server.
</p><p>
First, to enable CUPS-based printing through Samba, the following options should be set in your <code class="filename">smb.conf</code>
file <em class="parameter"><code>[global]</code></em> section:
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id399924"></a><em class="parameter"><code>printing = cups</code></em></td></tr><tr><td><a class="indexterm" name="id399936"></a><em class="parameter"><code>printcap = cups</code></em></td></tr></table><p>
When these parameters are specified, all manually set print directives (like <a class="indexterm" name="id399952"></a>print command or <a class="indexterm" name="id399959"></a>lppause command) in <code class="filename">smb.conf</code> (as well as in Samba itself) will be
ignored. Instead, Samba will directly interface with CUPS through its application program interface (API), as
long as Samba has been compiled with CUPS library (libcups) support. If Samba has not been compiled with CUPS
support, and if no other print commands are set up, then printing will use the <span class="emphasis"><em>System V</em></span>
AT&T command set, with the -oraw option automatically passing through (if you want your own defined print
commands to work with a Samba server that has CUPS support compiled in, simply use <a class="indexterm" name="id399981"></a>classicalprinting = sysv). This is illustrated in <a href="CUPS-printing.html#13small" title="Figure 22.15. Printing via CUPS/Samba Server.">the Printing via
CUPS/Samba Server diagram</a>.
</p><div class="figure"><a name="13small"></a><p class="title"><b>Figure 22.15. Printing via CUPS/Samba Server.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/13small.png" alt="Printing via CUPS/Samba Server."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400039"></a>Samba Receiving Job-Files and Passing Them to CUPS</h3></div></div></div><p>
Samba <span class="emphasis"><em>must</em></span> use its own spool directory (it is set by a line similar to <a class="indexterm" name="id400052"></a>path = /var/spool/samba, in the <em class="parameter"><code>[printers]</code></em> or <em class="parameter"><code>[printername]</code></em> section of <code class="filename">smb.conf</code>). Samba receives the job in its own spool space and passes it
into the spool directory of CUPS (the CUPS spool directory is set by the <em class="parameter"><code>RequestRoot</code></em>
directive in a line that defaults to <em class="parameter"><code>RequestRoot /var/spool/cups</code></em>). CUPS checks the
access rights of its spool directory and resets it to healthy values with every restart. We have seen quite a
few people who used a common spooling space for Samba and CUPS, and struggled for weeks with this
“<span class="quote">problem.</span>”
</p><p>
A Windows user authenticates only to Samba (by whatever means is
configured). If Samba runs on the same host as CUPS, you only need to
allow “<span class="quote">localhost</span>” to print. If it runs on different machines, you
need to make sure the Samba host gets access to printing on CUPS.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id400108"></a>Network PostScript RIP</h2></div></div></div><p>
This section discusses the use of CUPS filters on the server configuration where
clients make use of a PostScript driver with CUPS-PPDs.
</p><p>
<a class="indexterm" name="id400122"></a>
<a class="indexterm" name="id400129"></a>
<a class="indexterm" name="id400136"></a>
PPDs can control all print device options. They are usually provided by the manufacturer if you own
a PostScript printer, that is. PPD files are always a component of PostScript printer drivers on MS Windows or
Apple Mac OS systems. They are ASCII files containing user-selectable print options, mapped to appropriate
PostScript, PCL, or PJL commands for the target printer. Printer driver GUI dialogs translate these options
“<span class="quote">on the fly</span>” into buttons and drop-down lists for the user to select.
</p><p>
CUPS can load, without any conversions, the PPD file from any Windows (NT is recommended) PostScript driver
and handle the options. There is a Web browser interface to the print options (select <a href="http://localhost:631/printers/" target="_top">http://localhost:631/printers/</a> and click on one
<span class="guibutton">Configure Printer</span> button to see it) or a command-line interface (see <code class="literal">man
lpoptions</code> or see if you have <code class="literal">lphelp</code> on your system). There are also some
different GUI front-ends on Linux/UNIX, which can present PPD options to users. PPD options are normally meant
to be evaluated by the PostScript RIP on the real PostScript printer.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400187"></a>PPDs for Non-PS Printers on UNIX</h3></div></div></div><p>
<a class="indexterm" name="id400195"></a>
CUPS does not limit itself to “<span class="quote">real</span>” PostScript printers in its use of PPDs. The CUPS developers
have extended the scope of the PPD concept to also describe available device and driver options for
non-PostScript printers through CUPS-PPDs.
</p><p>
This is logical, because CUPS includes a fully featured PostScript interpreter (RIP). This RIP is based on
Ghostscript. It can process all received PostScript (and additionally many other file formats) from clients.
All CUPS-PPDs geared to non-PostScript printers contain an additional line, starting with the keyword
<em class="parameter"><code>*cupsFilter</code></em>. This line tells the CUPS print system which printer-specific filter to use
for the interpretation of the supplied PostScript. Thus CUPS lets all its printers appear as PostScript
devices to its clients, because it can act as a PostScript RIP for those printers, processing the received
PostScript code into a proper raster print format.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400224"></a>PPDs for Non-PS Printers on Windows</h3></div></div></div><p>
<a class="indexterm" name="id400232"></a>
CUPS-PPDs can also be used on Windows clients, on top of a “<span class="quote">core</span>” PostScript driver (now
recommended is the CUPS PostScript Driver for Windows NT/200x/XP; you can also use the Adobe one, with
limitations). This feature enables CUPS to do a few tricks no other spooler can do:
</p><div class="itemizedlist"><ul type="disc"><li><p>
Act as a networked PostScript RIP handling print files from all client platforms in a uniform way.
</p></li><li><p>
Act as a central accounting and billing server, since all files are passed through the pstops filter and are therefore
logged in the CUPS <code class="filename">page_log</code> file. <span class="emphasis"><em>Note:</em></span> this cannot happen with
“<span class="quote">raw</span>” print jobs, which always remain unfiltered per definition.
</p></li><li><p>
Enable clients to consolidate on a single PostScript driver, even for many different target printers.
</p></li></ul></div><p>
Using CUPS PPDs on Windows clients enables them to control all print job settings just as a UNIX client can do.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id400285"></a>Windows Terminal Servers (WTS) as CUPS Clients</h2></div></div></div><p>
This setup may be of special interest to people experiencing major problems in WTS environments. WTS often
need a multitude of non-PostScript drivers installed to run their clients' variety of different printer
models. This often imposes the price of much increased instability.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400296"></a>Printer Drivers Running in “<span class="quote">Kernel Mode</span>” Cause Many
Problems</h3></div></div></div><p>
Windows NT printer drivers, which run in “<span class="quote">kernel mode</span>”, introduce a high risk for the stability
of the system if the driver is not really stable and well-tested. And there are a lot of bad drivers out
there! Especially notorious is the example of the PCL printer driver that had an additional sound module
running to notify users via soundcard of their finished jobs. Do I need to say that this one was also reliably
causing “<span class="quote">blue screens of death</span>” on a regular basis?
</p><p>
PostScript drivers are generally well-tested. They are not known to cause any problems, even though they also
run in kernel mode. This might be because until now there have been only two different PostScript drivers: the
one from Adobe and the one from Microsoft. Both are well-tested and are as stable as you can imagine on
Windows. The CUPS driver is derived from the Microsoft one.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400328"></a>Workarounds Impose Heavy Limitations</h3></div></div></div><p>
In an attempt to work around problems, site administrators have resorted to restricting the
allowed drivers installed on their WTS to one generic PCL and one PostScript driver. This, however, restricts
the number of printer options available for clients to use. Often they can't get out more than simplex
prints from one standard paper tray, while their devices could do much better if driven by a different driver!
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400341"></a>CUPS: A “<span class="quote">Magical Stone</span>”?</h3></div></div></div><p>
<a class="indexterm" name="id400352"></a>
<a class="indexterm" name="id400359"></a>
Using a PostScript driver, enabled with a CUPS-PPD, seems to be a very elegant way to overcome all these
shortcomings. There are, depending on the version of Windows OS you use, up to three different PostScript
drivers now available: Adobe, Microsoft, and CUPS PostScript drivers. None of them is known to cause major
stability problems on WTS (even if used with many different PPDs). The clients will be able to (again) choose
paper trays, duplex printing, and other settings. However, there is a certain price for this too: a CUPS
server acting as a PostScript RIP for its clients requires more CPU and RAM than when just acting as a
“<span class="quote">raw spooling</span>” device. Plus, this setup is not yet widely tested, although the first feedbacks
look very promising.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400378"></a>PostScript Drivers with No Major Problems, Even in Kernel
Mode</h3></div></div></div><p>
<a class="indexterm" name="id400386"></a>
<a class="indexterm" name="id400393"></a>
<a class="indexterm" name="id400400"></a>
<a class="indexterm" name="id400406"></a>
<a class="indexterm" name="id400413"></a>
<a class="indexterm" name="id400420"></a>
More recent printer drivers on W200x and XP no longer run in kernel mode (unlike Windows NT). However, both
operating systems can still use the NT drivers, running in kernel mode (you can roughly tell which is which as
the drivers in subdirectory “<span class="quote">2</span>” of “<span class="quote">W32X86</span>” are “<span class="quote">old</span>” ones). As was
said before, the Adobe as well as the Microsoft PostScript drivers are not known to cause any stability
problems. The CUPS driver is derived from the Microsoft one. There is a simple reason for this: the MS DDK
(Device Development Kit) for Windows NT (which used to be available at no cost to licensees of Visual Studio)
includes the source code of the Microsoft driver, and licensees of Visual Studio are allowed to use and modify
it for their own driver development efforts. This is what the CUPS people have done. The license does not
allow them to publish the whole of the source code. However, they have released the “<span class="quote">diff</span>” under
the GPL, and if you are the owner of an “<span class="quote">MS DDK for Windows NT,</span>” you can check the driver
yourself.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id400456"></a>Configuring CUPS for Driver Download</h2></div></div></div><p>
As we have said before, all previously known methods to prepare client printer drivers on the Samba server for
download and Point'n'Print convenience of Windows workstations are working with CUPS, too. These methods were
described in <a href="classicalprinting.html" title="Chapter 21. Classical Printing Support">Classical Printing</a>. In reality, this is a pure Samba
business and relates only to the Samba-Windows client relationship.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400475"></a><span class="emphasis"><em>cupsaddsmb</em></span>: The Unknown Utility</h3></div></div></div><p>
<a class="indexterm" name="id400485"></a>
The <em class="parameter"><code>cupsaddsmb</code></em> utility (shipped with all current CUPS versions) is an alternative
method to transfer printer drivers into the Samba <em class="parameter"><code>[print$]</code></em> share. Remember, this
share is where clients expect drivers deposited and set up for download and installation. It makes the sharing
of any (or all) installed CUPS printers quite easy. <code class="literal">cupsaddsmb</code> can use the Adobe PostScript
driver as well as the newly developed CUPS PostScript driver for Windows NT/200x/XP.
<em class="parameter"><code>cupsaddsmb</code></em> does <span class="emphasis"><em>not</em></span> work with arbitrary vendor printer drivers,
but only with the <span class="emphasis"><em>exact</em></span> driver files that are named in its man page.
</p><p>
The CUPS printer driver is available from the CUPS download site. Its package name is
<code class="filename">cups-samba-[version].tar.gz</code>. It is preferred over the Adobe drivers because it has a
number of advantages:
</p><div class="itemizedlist"><ul type="disc"><li><p>It supports a much more accurate page accounting.</p></li><li><p>It supports banner pages and page labels on all printers.</p></li><li><p>It supports the setting of a number of job IPP attributes
(such as job priority, page label, and job billing).</p></li></ul></div><p>
However, currently only Windows NT, 2000, and XP are supported by the
CUPS drivers. You will also need to get the respective part of the Adobe driver
if you need to support Windows 95, 98, and Me clients.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400563"></a>Prepare Your <code class="filename">smb.conf</code> for <code class="literal">cupsaddsmb</code></h3></div></div></div><p>
Prior to running <code class="literal">cupsaddsmb</code>, you need the settings in
<code class="filename">smb.conf</code> as shown in <a href="CUPS-printing.html#cupsadd-ex" title="Example 22.3. smb.conf for cupsaddsmb Usage">the <code class="filename">smb.conf</code> for cupsaddsmb Usage</a>.
</p><div class="example"><a name="cupsadd-ex"></a><p class="title"><b>Example 22.3. smb.conf for cupsaddsmb Usage</b></p><div class="example-contents"><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td><a class="indexterm" name="id400631"></a><em class="parameter"><code>load printers = yes</code></em></td></tr><tr><td><a class="indexterm" name="id400644"></a><em class="parameter"><code>printing = cups</code></em></td></tr><tr><td><a class="indexterm" name="id400656"></a><em class="parameter"><code>printcap name = cups</code></em></td></tr><tr><td> </td></tr><tr><td><em class="parameter"><code>[printers]</code></em></td></tr><tr><td><a class="indexterm" name="id400678"></a><em class="parameter"><code>comment = All Printers</code></em></td></tr><tr><td><a class="indexterm" name="id400690"></a><em class="parameter"><code>path = /var/spool/samba</code></em></td></tr><tr><td><a class="indexterm" name="id400703"></a><em class="parameter"><code>browseable = no</code></em></td></tr><tr><td><a class="indexterm" name="id400715"></a><em class="parameter"><code>public = yes</code></em></td></tr><tr><td># setting depends on your requirements</td></tr><tr><td><a class="indexterm" name="id400731"></a><em class="parameter"><code>guest ok = yes</code></em></td></tr><tr><td><a class="indexterm" name="id400744"></a><em class="parameter"><code>writable = no</code></em></td></tr><tr><td><a class="indexterm" name="id400756"></a><em class="parameter"><code>printable = yes</code></em></td></tr><tr><td><a class="indexterm" name="id400769"></a><em class="parameter"><code>printer admin = root</code></em></td></tr><tr><td> </td></tr><tr><td><em class="parameter"><code>[print$]</code></em></td></tr><tr><td><a class="indexterm" name="id400790"></a><em class="parameter"><code>comment = Printer Drivers</code></em></td></tr><tr><td><a class="indexterm" name="id400803"></a><em class="parameter"><code>path = /etc/samba/drivers</code></em></td></tr><tr><td><a class="indexterm" name="id400816"></a><em class="parameter"><code>browseable = yes</code></em></td></tr><tr><td><a class="indexterm" name="id400828"></a><em class="parameter"><code>guest ok = no</code></em></td></tr><tr><td><a class="indexterm" name="id400841"></a><em class="parameter"><code>read only = yes</code></em></td></tr><tr><td><a class="indexterm" name="id400853"></a><em class="parameter"><code>write list = root</code></em></td></tr></table></div></div><br class="example-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id400868"></a>CUPS “<span class="quote">PostScript Driver for Windows NT/200x/XP</span>”</h3></div></div></div><p>
<a class="indexterm" name="id400878"></a>
CUPS users may get the exact same package from <a href="http://www.cups.org/software.html" target="_top">http://www.cups.org/software.html</a>. It is a separate package
from the CUPS-based software files, tagged as CUPS 1.1.x Windows NT/200x/XP Printer Driver for Samba (tar.gz,
192k). The filename to download is <code class="filename">cups-samba-1.1.x.tar.gz</code>. Upon untar and unzipping, it
will reveal these files:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>tar xvzf cups-samba-1.1.19.tar.gz</code></strong>
cups-samba.install
cups-samba.license
cups-samba.readme
cups-samba.remove
cups-samba.ss
</pre><p>
<a class="indexterm" name="id400921"></a>
<a class="indexterm" name="id400930"></a>
These have been packaged with the ESP meta-packager software EPM. The <code class="filename">*.install</code> and
<code class="filename">*.remove</code> files are simple shell scripts, which untar the <code class="filename">*.ss</code> (the
<code class="filename">*.ss</code> is nothing else but a tar archive, which can be untarred by “<span class="quote">tar</span>” too).
Then it puts the content into <code class="filename">/usr/share/cups/drivers/</code>. This content includes three
files:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>tar tv cups-samba.ss</code></strong>
cupsdrvr.dll
cupsui.dll
cups.hlp
</pre><p>
The <em class="parameter"><code>cups-samba.install</code></em> shell scripts are easy to
handle:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>./cups-samba.install</code></strong>
[....]
Installing software...
Updating file permissions...
Running post-install commands...
Installation is complete.
</pre><p>
The script should automatically put the driver files into the
<code class="filename">/usr/share/cups/drivers/</code> directory:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>cp /usr/share/drivers/cups.hlp /usr/share/cups/drivers/</code></strong>
</pre><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
Due to a bug, one recent CUPS release puts the <code class="filename">cups.hlp</code> driver file
into<code class="filename">/usr/share/drivers/</code> instead of <code class="filename">/usr/share/cups/drivers/</code>. To work
around this, copy/move the file (after running the <code class="literal">./cups-samba.install</code> script) manually to
the correct place.
</p></div><p>
<a class="indexterm" name="id401073"></a>
This new CUPS PostScript driver is currently binary only, but free of charge. No complete source code is
provided (yet). The reason is that it has been developed with the help of the Microsoft DDK and compiled with
Microsoft Visual Studio 6. Driver developers are not allowed to distribute the whole of the source code as
free software. However, CUPS developers released the “<span class="quote">diff</span>” in source code under the GPL, so
anybody with a license for Visual Studio and a DDK will be able to compile for himself or herself.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id401090"></a>Recognizing Different Driver Files</h3></div></div></div><p>
The CUPS drivers do not support the older Windows 95/98/Me, but only the Windows NT/2000/XP client.
</p><p>Windows NT, 2000, and XP are supported by:</p><div class="itemizedlist"><ul type="disc"><li><p>cups.hlp</p></li><li><p>cupsdrvr.dll</p></li><li><p>cupsui.dll</p></li></ul></div><p>
Adobe drivers are available for the older Windows 95/98/Me as well as
for Windows NT/2000/XP clients. The set of files is different from the
different platforms.
</p><p>Windows 95, 98, and ME are supported by:</p><div class="itemizedlist"><ul type="disc"><li><p>ADFONTS.MFM</p></li><li><p>ADOBEPS4.DRV</p></li><li><p>ADOBEPS4.HLP</p></li><li><p>DEFPRTR2.PPD</p></li><li><p>ICONLIB.DLL</p></li><li><p>PSMON.DLL</p></li></ul></div><p>Windows NT, 2000, and XP are supported by:</p><div class="itemizedlist"><ul type="disc"><li><p>ADOBEPS5.DLL</p></li><li><p>ADOBEPSU.DLL</p></li><li><p>ADOBEPSU.HLP</p></li></ul></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id401182"></a>
If both the Adobe driver files and the CUPS driver files for the support of Windows NT/200x/XP are presently
installed on the server, the Adobe files will be ignored and the CUPS files will be used. If you prefer
for whatever reason to use Adobe-only drivers, move away the three CUPS driver files.
The Windows 9x/Me clients use the Adobe drivers in any case.
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id401201"></a>Acquiring the Adobe Driver Files</h3></div></div></div><p>
Acquiring the Adobe driver files seems to be unexpectedly difficult for many users. They are not available on
the Adobe Web site as single files, and the self-extracting and/or self-installing Windows-.exe is not easy to
locate either. You probably need to use the included native installer and run the installation process on one
client once. This will install the drivers (and one generic PostScript printer) locally on the client. When
they are installed, share the generic PostScript printer. After this, the client's <em class="parameter"><code>[print$]</code></em> share holds the Adobe files, which you can get with smbclient from the CUPS host.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id401221"></a>ESP Print Pro PostScript Driver for Windows NT/200x/XP</h3></div></div></div><p>
<a class="indexterm" name="id401229"></a>
Users of the ESP Print Pro software are able to install the ESP print drivers package as an alternative to the
Adobe PostScript drivers. To do so, retrieve the driver files from the normal download area of the ESP Print
Pro software at <a href="http://www.easysw.com/software.html" target="_top">Easy Software</a> web site.
You need to locate the link labeled “<span class="quote">SAMBA</span>” among the <span class="guilabel">Download Printer Drivers for ESP
Print Pro 4.x</span> area and download the package. Once installed, you can prepare any driver by simply
highlighting the printer in the Printer Manager GUI and selecting <span class="guilabel">Export Driver...</span> from
the menu. Of course, you need to have prepared Samba beforehand to handle the driver files; that is, set up
the <em class="parameter"><code>[print$]</code></em> share, and so on. The ESP Print Pro package includes the CUPS driver
files as well as a (licensed) set of Adobe drivers for the Windows 95/98/Me client family.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id401275"></a>Caveats to Be Considered</h3></div></div></div><p>
<a class="indexterm" name="id401283"></a>
<a class="indexterm" name="id401290"></a>
<a class="indexterm" name="id401297"></a>
<a class="indexterm" name="id401304"></a>
Once you have run the install script (and possibly manually moved the <code class="filename">cups.hlp</code> file to
<code class="filename">/usr/share/cups/drivers/</code>), the driver is ready to be put into Samba's <em class="parameter"><code>[print$]</code></em> share (which often maps to <code class="filename">/etc/samba/drivers/</code> and contains a
subdirectory tree with <span class="emphasis"><em>WIN40</em></span> and <span class="emphasis"><em>W32X86</em></span> branches). You do this by
running <code class="literal">cupsaddsmb</code> (see also <code class="literal">man cupsaddsmb</code> for CUPS since release
1.1.16).
</p><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3><p>
<a class="indexterm" name="id401360"></a>
<a class="indexterm" name="id401366"></a>
You may need to put root into the smbpasswd file by running <code class="literal">smbpasswd</code>; this is especially
important if you should run this whole procedure for the first time and are not working in an environment
where everything is configured for <span class="emphasis"><em>single sign-on</em></span> to a Windows Domain Controller.
</p></div><p>
Once the driver files are in the <em class="parameter"><code>[print$]</code></em> share and are initialized, they are ready
to be downloaded and installed by the Windows NT/200x/XP clients.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
Win 9x/Me clients will not work with the CUPS PostScript driver. For these you still need to use the
<code class="filename">ADOBE*.*</code> drivers, as previously stated.
</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
It is not harmful if you still have the <code class="filename">ADOBE*.*</code> driver files from previous installations
in the <code class="filename">/usr/share/cups/drivers/</code> directory. The new <code class="literal">cupsaddsmb</code> (from
1.1.16) will automatically prefer its own drivers if it finds both.
</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id401436"></a>
<a class="indexterm" name="id401443"></a>
Should your Windows clients have had the old <code class="filename">ADOBE*.*</code> files for the Adobe PostScript
driver installed, the download and installation of the new CUPS PostScript driver for Windows NT/200x/XP will
fail at first. You need to wipe the old driver from the clients first. It is not enough to
“<span class="quote">delete</span>” the printer, because the driver files will still be kept by the clients and re-used if
you try to re-install the printer. To really get rid of the Adobe driver files on the clients, open the
<span class="guilabel">Printers</span> folder (possibly via <span class="guilabel">Start -> Settings -> Control Panel ->
Printers</span>), right-click on the folder background, and select <span class="guimenuitem">Server
Properties</span>. When the new dialog opens, select the <span class="guilabel">Drivers</span> tab. On the list
select the driver you want to delete and click the <span class="guilabel">Delete</span> button. This will only work if
there is not one single printer left that uses that particular driver. You need to “<span class="quote">delete</span>” all
printers using this driver in the <span class="guilabel">Printers</span> folder first. You will need Administrator
privileges to do this.
</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id401510"></a>
<a class="indexterm" name="id401519"></a>
Once you have successfully downloaded the CUPS PostScript driver to a client, you can easily switch all
printers to this one by proceeding as described in <a href="classicalprinting.html" title="Chapter 21. Classical Printing Support">Classical Printing
Support</a>. Either change a driver for an existing printer by running the <span class="guilabel">Printer
Properties</span> dialog, or use <code class="literal">rpcclient</code> with the <code class="literal">setdriver</code>
subcommand.
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id401555"></a>Windows CUPS PostScript Driver Versus Adobe Driver</h3></div></div></div><p>
Are you interested in a comparison between the CUPS and the Adobe PostScript drivers? For our purposes, these
are the most important items that weigh in favor of CUPS:
</p><div class="itemizedlist"><ul type="disc"><li><p>No hassle with the Adobe EULA.</p></li><li><p>No hassle with the question, “<span class="quote">Where do I
get the ADOBE*.* driver files?</span>”</p></li><li><p>
<a class="indexterm" name="id401583"></a>
The Adobe drivers (on request of the printer PPD associated with them) often put a PJL header in front of the
main PostScript part of the print file. Thus, the print file starts with <em class="parameter"><code><1B
>%-12345X</code></em> or <em class="parameter"><code><escape>%-12345X</code></em> instead of
<em class="parameter"><code>%!PS</code></em>. This leads to the CUPS daemon autotyping the incoming file as a print-ready file,
not initiating a pass through the <em class="parameter"><code>pstops</code></em> filter (to speak more technically, it is not
regarded as the generic MIME-type <a class="indexterm" name="id401617"></a>
<em class="parameter"><code>application/postscript</code></em>, but as the more special MIME type
<a class="indexterm" name="id401630"></a>
<em class="parameter"><code>application/cups.vnd-postscript</code></em>), which therefore also leads to the page accounting in
<em class="parameter"><code>/var/log/cups/page_log</code></em> not receiving the exact number of pages; instead the dummy page
number of “<span class="quote">1</span>” is logged in a standard setup).
</p></li><li><p>The Adobe driver has more options to misconfigure the
<a class="indexterm" name="id401658"></a>
PostScript generated by it (like setting it inadvertently to
<span class="guilabel">Optimize for Speed</span> instead of
<span class="guilabel">Optimize for Portability</span>, which
could lead to CUPS being unable to process it).</p></li><li><p>The CUPS PostScript driver output sent by Windows
<a class="indexterm" name="id401683"></a>
clients to the CUPS server is guaranteed to autotype
as the generic MIME type <em class="parameter"><code>application/postscript</code></em>,
thus passing through the CUPS <em class="parameter"><code>pstops</code></em> filter and logging the
correct number of pages in the <code class="filename">page_log</code> for
accounting and quota purposes.</p></li><li><p>
<a class="indexterm" name="id401713"></a>
The CUPS PostScript driver supports the sending of additional standard (IPP) print options by Windows
NT/200x/XP clients. Such additional print options are naming the CUPS standard <span class="emphasis"><em>banner
pages</em></span> (or the custom ones, should they be installed at the time of driver download), using the CUPS
page-label option, setting a job priority, and setting the scheduled time of printing (with the option to
support additional useful IPP job attributes in the future).
</p></li><li><p>The CUPS PostScript driver supports the inclusion of
the new <em class="parameter"><code>*cupsJobTicket</code></em> comments at the
beginning of the PostScript file (which could be used in the future
for all sorts of beneficial extensions on the CUPS side, but which will
not disturb any other applications because they will regard it as a comment
and simply ignore it).</p></li><li><p>The CUPS PostScript driver will be the heart of the
fully fledged CUPS IPP client for Windows NT/200x/XP to be released soon
(probably alongside the first beta release for CUPS 1.2).</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id401750"></a>Run cupsaddsmb (Quiet Mode)</h3></div></div></div><p>
<a class="indexterm" name="id401758"></a>
<a class="indexterm" name="id401765"></a>
The <code class="literal">cupsaddsmb</code> command copies the needed files into your <em class="parameter"><code>[print$]</code></em>
share. Additionally, the PPD associated with this printer is copied from <code class="filename">/etc/cups/ppd/</code>
to <em class="parameter"><code>[print$]</code></em>. There the files wait for convenient Windows client installations via
Point'n'Print. Before we can run the command successfully, we need to be sure that we can authenticate toward
Samba. If you have a small network, you are probably using user-level security (<a class="indexterm" name="id401798"></a>security = user).
</p><p>
Here is an example of a successfully run <code class="literal">cupsaddsmb</code> command:
<a class="indexterm" name="id401815"></a>
<a class="indexterm" name="id401822"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>cupsaddsmb -U root infotec_IS2027</code></strong>
Password for root required to access localhost via Samba: <strong class="userinput"><code>['secret']</code></strong>
</pre><p>
<a class="indexterm" name="id401853"></a>
To share <span class="emphasis"><em>all</em></span> printers and drivers, use the
<code class="option">-a</code> parameter instead of a printer name. Since
<code class="literal">cupsaddsmb</code> “<span class="quote">exports</span>” the printer drivers to Samba, it should be
obvious that it only works for queues with a CUPS driver associated.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id401880"></a>Run cupsaddsmb with Verbose Output</h3></div></div></div><p>
<a class="indexterm" name="id401888"></a>
Probably you want to see what's going on. Use the
<code class="option">-v</code> parameter to get a more verbose output. The
output below was edited for better readability: all “<span class="quote">\</span>” at the end of
a line indicate that I inserted an artificial line break plus some
indentation here:
<a class="indexterm" name="id401904"></a>
<a class="indexterm" name="id401913"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>cupsaddsmb -U root -v infotec_2105</code></strong>
Password for root required to access localhost via GANDALF:
Running command: smbclient //localhost/print\$ -N -U'root%secret' \
-c 'mkdir W32X86; \
put /var/spool/cups/tmp/3e98bf2d333b5 W32X86/infotec_2105.ppd; \
put /usr/share/cups/drivers/cupsdrvr.dll W32X86/cupsdrvr.dll; \
put /usr/share/cups/drivers/cupsui.dll W32X86/cupsui.dll; \
put /usr/share/cups/drivers/cups.hlp W32X86/cups.hlp'
added interface ip=10.160.51.60 bcast=10.160.51.255 nmask=255.255.252.0
Domain=[CUPS-PRINT] OS=[UNIX] Server=[Samba 2.2.7a]
NT_STATUS_OBJECT_NAME_COLLISION making remote directory \W32X86
putting file /var/spool/cups/tmp/3e98bf2d333b5 as \W32X86/infotec_2105.ppd
putting file /usr/share/cups/drivers/cupsdrvr.dll as \W32X86/cupsdrvr.dll
putting file /usr/share/cups/drivers/cupsui.dll as \W32X86/cupsui.dll
putting file /usr/share/cups/drivers/cups.hlp as \W32X86/cups.hlp
Running command: rpcclient localhost -N -U'root%secret'
-c 'adddriver "Windows NT x86" \
"infotec_2105:cupsdrvr.dll:infotec_2105.ppd:cupsui.dll:cups.hlp:NULL: \
RAW:NULL"'
cmd = adddriver "Windows NT x86" \
"infotec_2105:cupsdrvr.dll:infotec_2105.ppd:cupsui.dll:cups.hlp:NULL: \
RAW:NULL"
Printer Driver infotec_2105 successfully installed.
Running command: smbclient //localhost/print\$ -N -U'root%secret' \
-c 'mkdir WIN40; \
put /var/spool/cups/tmp/3e98bf2d333b5 WIN40/infotec_2105.PPD; \
put /usr/share/cups/drivers/ADFONTS.MFM WIN40/ADFONTS.MFM; \
put /usr/share/cups/drivers/ADOBEPS4.DRV WIN40/ADOBEPS4.DRV; \
put /usr/share/cups/drivers/ADOBEPS4.HLP WIN40/ADOBEPS4.HLP; \
put /usr/share/cups/drivers/DEFPRTR2.PPD WIN40/DEFPRTR2.PPD; \
put /usr/share/cups/drivers/ICONLIB.DLL WIN40/ICONLIB.DLL; \
put /usr/share/cups/drivers/PSMON.DLL WIN40/PSMON.DLL;'
added interface ip=10.160.51.60 bcast=10.160.51.255 nmask=255.255.252.0
Domain=[CUPS-PRINT] OS=[UNIX] Server=[Samba 2.2.7a]
NT_STATUS_OBJECT_NAME_COLLISION making remote directory \WIN40
putting file /var/spool/cups/tmp/3e98bf2d333b5 as \WIN40/infotec_2105.PPD
putting file /usr/share/cups/drivers/ADFONTS.MFM as \WIN40/ADFONTS.MFM
putting file /usr/share/cups/drivers/ADOBEPS4.DRV as \WIN40/ADOBEPS4.DRV
putting file /usr/share/cups/drivers/ADOBEPS4.HLP as \WIN40/ADOBEPS4.HLP
putting file /usr/share/cups/drivers/DEFPRTR2.PPD as \WIN40/DEFPRTR2.PPD
putting file /usr/share/cups/drivers/ICONLIB.DLL as \WIN40/ICONLIB.DLL
putting file /usr/share/cups/drivers/PSMON.DLL as \WIN40/PSMON.DLL
Running command: rpcclient localhost -N -U'root%secret' \
-c 'adddriver "Windows 4.0" \
"infotec_2105:ADOBEPS4.DRV:infotec_2105.PPD:NULL:ADOBEPS4.HLP: \
PSMON.DLL:RAW:ADOBEPS4.DRV,infotec_2105.PPD,ADOBEPS4.HLP,PSMON.DLL, \
ADFONTS.MFM,DEFPRTR2.PPD,ICONLIB.DLL"'
cmd = adddriver "Windows 4.0" "infotec_2105:ADOBEPS4.DRV:\
infotec_2105.PPD:NULL:ADOBEPS4.HLP:PSMON.DLL:RAW:ADOBEPS4.DRV,\
infotec_2105.PPD,ADOBEPS4.HLP,PSMON.DLL,ADFONTS.MFM,DEFPRTR2.PPD,\
ICONLIB.DLL"
Printer Driver infotec_2105 successfully installed.
Running command: rpcclient localhost -N -U'root%secret' \
-c 'setdriver infotec_2105 infotec_2105'
cmd = setdriver infotec_2105 infotec_2105
Successfully set infotec_2105 to driver infotec_2105.
</pre><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
You will see the root password for the Samba account printed on screen.
</p></div><p>
If you look closely, you'll discover your root password was transferred unencrypted over the wire, so beware!
Also, if you look further, you may discover error messages like NT_STATUS_OBJECT_NAME_COLLISION in the output.
This will occur when the directories WIN40 and W32X86 already existed in the <em class="parameter"><code>[print$]</code></em>
driver download share (from a previous driver installation). These are harmless warning messages.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id402011"></a>Understanding cupsaddsmb</h3></div></div></div><p>
<a class="indexterm" name="id402019"></a>
What has happened? What did <code class="literal">cupsaddsmb</code> do? There are five stages of the procedure:
</p><div class="orderedlist"><ol type="1"><li><p>
<a class="indexterm" name="id402043"></a>
Call the CUPS server via IPP and request the driver files and the PPD file for the named printer.</p></li><li><p>Store the files temporarily in the local TEMPDIR (as defined in <code class="filename">cupsd.conf</code>).</p></li><li><p>Connect via smbclient to the Samba server's <em class="parameter"><code>[print$]</code></em> share and put the files into the
share's WIN40 (for Windows 9x/Me) and W32X86 (for Windows NT/200x/XP) subdirectories.</p></li><li><p>
<a class="indexterm" name="id402077"></a>
Connect via rpcclient to the Samba server and execute the <code class="literal">adddriver</code> command with the correct parameters.
</p></li><li><p>
<a class="indexterm" name="id402098"></a>
Connect via rpcclient to the Samba server a second time and execute the <code class="literal">setdriver</code> command.</p></li></ol></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
You can run the <code class="literal">cupsaddsmb</code> utility with parameters to specify one remote host as Samba host
and a second remote host as CUPS host. Especially if you want to get a deeper understanding, it is a good idea
to try it and see more clearly what is going on (though in real life most people will have their CUPS and
Samba servers run on the same host):
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>cupsaddsmb -H sambaserver -h cupsserver -v printer</code></strong>
</pre><p>
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id402147"></a>How to Recognize If cupsaddsmb Completed Successfully</h3></div></div></div><p>
You <span class="emphasis"><em>must</em></span> always check if the utility completed
successfully in all fields. You need at minimum these three messages
among the output:
</p><div class="orderedlist"><ol type="1"><li><p><span class="emphasis"><em>Printer Driver infotec_2105 successfully
installed.</em></span> # (for the W32X86 == Windows NT/200x/XP
architecture).</p></li><li><p><span class="emphasis"><em>Printer Driver infotec_2105 successfully
installed.</em></span> # (for the WIN40 == Windows 9x/Me
architecture).</p></li><li><p><span class="emphasis"><em>Successfully set [printerXPZ] to driver
[printerXYZ].</em></span></p></li></ol></div><p>
These messages are probably not easily recognized in the general
output. If you run <code class="literal">cupsaddsmb</code> with the <code class="option">-a</code>
parameter (which tries to prepare <span class="emphasis"><em>all</em></span> active CUPS
printer drivers for download), you might miss if individual printer
drivers had problems installing properly. A redirection of the
output will help you analyze the results in retrospective.
</p><p>
If you get:
</p><pre class="screen">
SetPrinter call failed!
result was WERR_ACCESS_DENIED
</pre><p>
it means that you might have set <a class="indexterm" name="id402217"></a>use client driver = yes for this printer.
Setting it to “<span class="quote">no</span>” will solve the problem. Refer to the <code class="filename">smb.conf</code> man page for explanation of
the <em class="parameter"><code>use client driver</code></em>.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
It is impossible to see any diagnostic output if you do not run <code class="literal">cupsaddsmb</code> in verbose mode.
Therefore, we strongly recommend against use of the default quiet mode. It will hide any problems from you that
might occur.
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id402254"></a>cupsaddsmb with a Samba PDC</h3></div></div></div><p>
<a class="indexterm" name="id402262"></a>
<a class="indexterm" name="id402269"></a>
Can't get the standard <code class="literal">cupsaddsmb</code> command to run on a Samba PDC? Are you asked for the
password credential again and again, and the command just will not take off at all? Try one of these
variations:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>cupsaddsmb -U MIDEARTH\\root -v printername</code></strong>
<code class="prompt">root# </code><strong class="userinput"><code>cupsaddsmb -H SAURON -U MIDEARTH\\root -v printername</code></strong>
<code class="prompt">root# </code><strong class="userinput"><code>cupsaddsmb -H SAURON -U MIDEARTH\\root -h cups-server -v printername</code></strong>
</pre><p>
(Note the two backslashes: the first one is required to “<span class="quote">escape</span>” the second one).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id402332"></a>cupsaddsmb Flowchart</h3></div></div></div><p>
<a class="indexterm" name="id402339"></a>
<a class="indexterm" name="id402346"></a>
<a href="CUPS-printing.html#small14" title="Figure 22.16. cupsaddsmb Flowchart.">The cupsaddsmb Flowchart</a> shows a chart about the procedures, command flows, and
data flows of the <code class="literal">cupaddsmb</code> command. Note again: cupsaddsmb is
not intended to, and does not work with, raw print queues!
</p><div class="figure"><a name="small14"></a><p class="title"><b>Figure 22.16. cupsaddsmb Flowchart.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/14small.png" alt="cupsaddsmb Flowchart."></div></div></div><br class="figure-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id402410"></a>Installing the PostScript Driver on a Client</h3></div></div></div><p>
<a class="indexterm" name="id402418"></a>
<a class="indexterm" name="id402425"></a>
After <code class="literal">cupsaddsmb</code> is completed, your driver is prepared for the clients to use. Here are the
steps you must perform to download and install it via Point'n'Print. From a Windows client, browse to the
CUPS/Samba server:
</p><div class="itemizedlist"><ul type="disc"><li><p>
<a class="indexterm" name="id402446"></a>
Open the <span class="guilabel">Printers</span> share of Samba in Network Neighborhood.</p></li><li><p>Right-click on the printer in question.</p></li><li><p>From the opening context menu select
<span class="guimenuitem">Install...</span> or
<span class="guimenuitem">Connect...</span> (depending on the Windows version you use).</p></li></ul></div><p>
After a few seconds, there should be a new printer in your client's <span class="emphasis"><em>local</em></span>
<span class="guilabel">Printers</span> folder. On Windows XP it will follow a naming convention of
<span class="emphasis"><em>PrinterName on SambaServer</em></span>. (In my current case it is infotec_2105 on kde-bitshop). If
you want to test it and send your first job from an application like Winword, the new printer appears in a
<code class="filename">\\SambaServer\PrinterName</code> entry in the drop-down list of available printers.
</p><p>
<a class="indexterm" name="id402510"></a>
<a class="indexterm" name="id402517"></a>
<a class="indexterm" name="id402524"></a>
<code class="literal">cupsaddsmb</code> will only reliably work with CUPS version 1.1.15 or higher and with Samba
version 2.2.4, or later. If it does not work, or if the automatic printer driver download to the clients does
not succeed, you can still manually install the CUPS printer PPD on top of the Adobe PostScript driver on
clients. Then point the client's printer queue to the Samba printer share for a UNC type of connection:
</p><pre class="screen">
<code class="prompt">C:\> </code><strong class="userinput"><code>net use lpt1: \\sambaserver\printershare /user:ntadmin</code></strong>
</pre><p>
should you desire to use the CUPS networked PostScript RIP functions. (Note that user “<span class="quote">ntadmin</span>”
needs to be a valid Samba user with the required privileges to access the printershare.) This sets up the
printer connection in the traditional LanMan way (not using MS-RPC).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cups-avoidps1"></a>Avoiding Critical PostScript Driver Settings on the Client</h3></div></div></div><p>
Printing works, but there are still problems. Most jobs print well, some do not print at all. Some jobs have
problems with fonts, which do not look very good. Some jobs print fast and some are dead-slow. Many of these
problems can be greatly reduced or even completely eliminated if you follow a few guidelines. Remember, if
your print device is not PostScript-enabled, you are treating your Ghostscript installation on your CUPS host
with the output your client driver settings produce. Treat it well:
</p><div class="itemizedlist"><ul type="disc"><li><p>
Avoid the PostScript Output Option: Optimize for Speed setting. Use the Optimize for Portability instead
(Adobe PostScript driver).</p></li><li><p>
Don't use the Page Independence: NO setting. Instead, use Page Independence: YES (CUPS PostScript Driver).
</p></li><li><p>
Recommended is the True Type Font Downloading Option: Native True Type over Automatic and Outline;
you should by all means avoid Bitmap (Adobe PostScript Driver).</p></li><li><p>
Choose True Type Font: Download as Softfont into Printer over the default Replace by Device
Font (for exotic fonts, you may need to change it back to get a printout at all; Adobe).</p></li><li><p>
Sometimes you can choose PostScript Language Level: in case of problems try 2
instead of 3 (the latest ESP Ghostscript package handles Level 3 PostScript very well; Adobe).
</p></li><li><p>
Say Yes to PostScript Error Handler (Adobe).</p></li></ul></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id402619"></a>Installing PostScript Driver Files Manually Using rpcclient</h2></div></div></div><p>
Of course, you can run all the commands that are embedded into the
cupsaddsmb convenience utility yourself, one by one, and upload
and prepare the driver files for future client downloads.
</p><div class="orderedlist"><ol type="1"><li><p>Prepare Samba (a CUPS print queue with the name of the
printer should be there. We are providing the driver now).</p></li><li><p>Copy all files to <em class="parameter"><code>[print$]</code></em>.</p></li><li><p>
<a class="indexterm" name="id402655"></a>
Run <code class="literal">rpcclient adddriver</code>
(for each client architecture you want to support).</p></li><li><p>
<a class="indexterm" name="id402675"></a>
Run <code class="literal">rpcclient setdriver.</code></p></li></ol></div><p>
<a class="indexterm" name="id402694"></a>
<a class="indexterm" name="id402703"></a>
<a class="indexterm" name="id402712"></a>
<a class="indexterm" name="id402721"></a>
<a class="indexterm" name="id402730"></a>
We are going to do this now. First, read the man page on <em class="parameter"><code>rpcclient</code></em> to get a first idea.
Look at all the printing-related subcommands: <code class="literal">enumprinters</code>, <code class="literal">enumdrivers</code>,
<code class="literal">enumports</code>, <code class="literal">adddriver</code>, and <code class="literal">setdriver</code> are among the
most interesting ones. <em class="parameter"><code>rpcclient</code></em> implements an important part of the MS-RPC protocol.
You can use it to query (and command) a Windows NT (or 200x/XP) PC, too. MS-RPC is used by Windows clients,
among other things, to benefit from the Point'n'Print features. Samba can now mimic this as well.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id402785"></a>A Check of the rpcclient man Page</h3></div></div></div><p>
First let's check the <em class="parameter"><code>rpcclient</code></em> man page. Here are two relevant passages:
</p><p>
<a class="indexterm" name="id402803"></a>
<a class="indexterm" name="id402810"></a>
<a class="indexterm" name="id402816"></a>
<code class="literal">adddriver <arch> <config></code> Execute an <code class="literal">AddPrinterDriver()</code> RPC
to install the printer driver information on the server. The driver files should already exist in the
directory returned by <code class="literal">getdriverdir</code>. Possible values for <em class="parameter"><code>arch</code></em> are the
same as those for the <code class="literal">getdriverdir</code> command. The <em class="parameter"><code>config</code></em> parameter is
defined as follows:
</p><pre class="screen">
Long Printer Name:\
Driver File Name:\
Data File Name:\
Config File Name:\
Help File Name:\
Language Monitor Name:\
Default Data Type:\
Comma Separated list of Files
</pre><p>
Any empty fields should be entered as the string “<span class="quote">NULL</span>”.
</p><p>
Samba does not need to support the concept of print monitors, since these only apply to local printers whose
drivers can use a bidirectional link for communication. This field should be “<span class="quote">NULL</span>”. On a remote
NT print server, the print monitor for a driver must already be installed before adding the driver or else the
RPC will fail.
</p><p>
<a class="indexterm" name="id402887"></a>
<a class="indexterm" name="id402894"></a>
<code class="literal">setdriver <printername> <drivername></code> Execute a <code class="literal">SetPrinter()</code>
command to update the printer driver associated with an installed printer. The printer driver must already be
correctly installed on the print server.
</p><p>
<a class="indexterm" name="id402917"></a>
<a class="indexterm" name="id402924"></a>
See also the <code class="literal">enumprinters</code> and <code class="literal">enumdrivers</code> commands to
obtain a list of installed printers and drivers.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id402945"></a>Understanding the rpcclient man Page</h3></div></div></div><p>
<a class="indexterm" name="id402953"></a>
The <span class="emphasis"><em>exact</em></span> format isn't made too clear by the man page, since you have to deal with some
parameters containing spaces. Here is a better description for it. We have line-broken the command and
indicated the breaks with “<span class="quote">\</span>”. Usually you would type the command in one line without the line
breaks:
</p><pre class="screen">
adddriver "Architecture" \
"LongPrinterName:DriverFile:DataFile:ConfigFile:HelpFile:\
LanguageMonitorFile:DataType:ListOfFiles,Comma-separated"
</pre><p>
What the man pages denote as a simple <em class="parameter"><code><config></code></em> keyword in reality consists of
eight colon-separated fields. The last field may take multiple (in some very insane cases, even 20 different
additional) files. This might sound confusing at first. What the man pages call the
“<span class="quote">LongPrinterName</span>” in reality should be called the “<span class="quote">Driver Name</span>”. You can name it
anything you want, as long as you use this name later in the <code class="literal">rpcclient ... setdriver</code>
command. For practical reasons, many name the driver the same as the printer.
</p><p>
It isn't simple at all. I hear you asking: “<span class="quote">How do I know which files are Driver File</span>”,
“<span class="quote">Data File</span>”, “<span class="quote">Config File</span>”, “<span class="quote">Help File</span>” and “<span class="quote">Language Monitor
File in each case?</span>” For an answer, you may want to have a look at how a Windows NT box with a shared
printer presents the files to us. Remember that this whole procedure has to be developed by the Samba Team by
listening to the traffic caused by Windows computers on the wire. We may as well turn to a Windows box now and
access it from a UNIX workstation. We will query it with <code class="literal">rpcclient</code> to see what it tells us
and try to understand the man page more clearly.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id403037"></a>Producing an Example by Querying a Windows Box</h3></div></div></div><p>
<a class="indexterm" name="id403045"></a>
<a class="indexterm" name="id403055"></a>
We could run <code class="literal">rpcclient</code> with a <code class="literal">getdriver</code> or a
<code class="literal">getprinter</code> subcommand (in level 3 verbosity) against it. Just sit down at a UNIX or Linux
workstation with the Samba utilities installed, then type the following command:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -U'user%secret' NT-SERVER -c 'getdriver printername 3'</code></strong>
</pre><p>
From the result it should become clear which is which. Here is an example from my installation:
<a class="indexterm" name="id403103"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -U'Danka%xxxx' W200xSERVER \
-c'getdriver "DANKA InfoStream Virtual Printer" 3'</code></strong>
cmd = getdriver "DANKA InfoStream Virtual Printer" 3
[Windows NT x86]
Printer Driver Info 3:
Version: [2]
Driver Name: [DANKA InfoStream]
Architecture: [Windows NT x86]
Driver Path: [C:\WINNT\System32\spool\DRIVERS\W32X86\2\PSCRIPT.DLL]
Datafile: [C:\WINNT\System32\spool\DRIVERS\W32X86\2\INFOSTRM.PPD]
Configfile: [C:\WINNT\System32\spool\DRIVERS\W32X86\2\PSCRPTUI.DLL]
Helpfile: [C:\WINNT\System32\spool\DRIVERS\W32X86\2\PSCRIPT.HLP]
Dependentfiles: []
Dependentfiles: []
Dependentfiles: []
Dependentfiles: []
Dependentfiles: []
Dependentfiles: []
Dependentfiles: []
Monitorname: []
Defaultdatatype: []
</pre><p>
Some printer drivers list additional files under the label <em class="parameter"><code>Dependentfiles</code></em>, and these
would go into the last field <em class="parameter"><code>ListOfFiles,Comma-separated</code></em>. For the CUPS PostScript
drivers, we do not need any (nor would we for the Adobe PostScript driver); therefore, the field will get a
“<span class="quote">NULL</span>” entry.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id403163"></a>Requirements for adddriver and setdriver to Succeed</h3></div></div></div><p>
<a class="indexterm" name="id403171"></a>
<a class="indexterm" name="id403180"></a>
<a class="indexterm" name="id403187"></a>
From the man page (and from the quoted output of <code class="literal">cupsaddsmb</code> above) it becomes clear that
you need to have certain conditions in order to make the manual uploading and initializing of the driver files
succeed. The two <code class="literal">rpcclient</code> subcommands (<code class="literal">adddriver</code> and
<code class="literal">setdriver</code>) need to encounter the following preconditions to complete successfully:
</p><div class="itemizedlist"><ul type="disc"><li><p>You are connected as <a class="indexterm" name="id403227"></a>printer admin or root (this is
<span class="emphasis"><em>not</em></span> the “<span class="quote">Printer Operators</span>” group in NT, but the <span class="emphasis"><em>printer
admin</em></span> group as defined in the <em class="parameter"><code>[global]</code></em> section of <code class="filename">smb.conf</code>).
</p></li><li><p>Copy all required driver files to <code class="filename">\\SAMBA\print$\w32x86</code> and
<code class="filename">\\SAMBA\print$\win40</code> as appropriate. They will end up in the “<span class="quote">0</span>” respective
“<span class="quote">2</span>” subdirectories later. For now, <span class="emphasis"><em>do not</em></span> put them there; they'll be
automatically used by the <code class="literal">adddriver</code> subcommand. (If you use <code class="literal">smbclient</code> to
put the driver files into the share, note that you need to escape the “<span class="quote">$</span>”: <code class="literal">smbclient
//sambaserver/print\$ -U root.</code>)</p></li><li><p>The user you're connecting as must be able to write to
the <em class="parameter"><code>[print$]</code></em> share and create
subdirectories.</p></li><li><p>The printer you are going to set up for the Windows
clients needs to be installed in CUPS already.</p></li><li><p>
<a class="indexterm" name="id403328"></a>
<a class="indexterm" name="id403337"></a>
The CUPS printer must be known to Samba; otherwise the <code class="literal">setdriver</code> subcommand fails with an
NT_STATUS_UNSUCCESSFUL error. To check if the printer is known by Samba, you may use the
<code class="literal">enumprinters</code> subcommand to <code class="literal">rpcclient</code>. A long-standing bug prevented a
proper update of the printer list until every smbd process had received a SIGHUP or was restarted. Remember
this in case you've created the CUPS printer just recently and encounter problems: try restarting Samba.
</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id403371"></a>Manual Driver Installation in 15 Steps</h3></div></div></div><p>
We are going to install a printer driver now by manually executing all
required commands. Because this may seem a rather complicated process at
first, we go through the procedure step by step, explaining every
single action item as it comes up.
</p><div class="procedure"><a name="id403382"></a><p class="title"><b>Procedure 22.2. Manual Driver Installation</b></p><ol type="1"><li><p class="title"><b>Install the printer on CUPS.</b></p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>lpadmin -p mysmbtstprn -v socket://10.160.51.131:9100 -E \
-P canonIR85.ppd</code></strong>
</pre><p>
This installs a printer with the name <em class="parameter"><code>mysmbtstprn</code></em>
to the CUPS system. The printer is accessed via a socket
(a.k.a. JetDirect or Direct TCP/IP) connection. You need to be root
for this step.
</p></li><li><p class="title"><b>(Optional.) Check if the printer is recognized by Samba.</b></p><p>
<a class="indexterm" name="id403435"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'enumprinters' localhost \
| grep -C2 mysmbtstprn</code></strong>
flags:[0x800000]
name:[\\kde-bitshop\mysmbtstprn]
description:[\\kde-bitshop\mysmbtstprn,,mysmbtstprn]
comment:[mysmbtstprn]
</pre><p>
</p><p>
This should show the printer in the list. If not, stop and restart the Samba daemon (smbd) or send a HUP signal:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>kill -HUP `pidof smbd`</code></strong>
</pre><p>
Check again. Troubleshoot and repeat until successful. Note the “<span class="quote">empty</span>” field between the two
commas in the “<span class="quote">description</span>” line. The driver name would appear here if there was one already. You
need to know root's Samba password (as set by the <code class="literal">smbpasswd</code> command) for this step and most
of the following steps. Alternatively, you can authenticate as one of the users from the “<span class="quote">write
list</span>” as defined in <code class="filename">smb.conf</code> for <em class="parameter"><code>[print$]</code></em>.
</p></li><li><p class="title"><b>(Optional.) Check if Samba knows a driver for the printer.</b></p><p>
<a class="indexterm" name="id403526"></a>
<a class="indexterm" name="id403536"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2'\
localhost | grep driver </code></strong>
drivername:[]
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2' \
localhost | grep -C4 driv</code></strong>
servername:[\\kde-bitshop]
printername:[\\kde-bitshop\mysmbtstprn]
sharename:[mysmbtstprn]
portname:[Samba Printer Port]
drivername:[]
comment:[mysmbtstprn]
location:[]
sepfile:[]
printprocessor:[winprint]
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -U root%xxxx -c 'getdriver mysmbtstprn' localhost</code></strong>
result was WERR_UNKNOWN_PRINTER_DRIVER
</pre><p>
None of the three commands shown above should show a driver.
This step was done for the purpose of demonstrating this condition. An
attempt to connect to the printer at this stage will prompt a
message along the lines of, “<span class="quote">The server does not have the required printer
driver installed.</span>”
</p></li><li><p class="title"><b>Put all required driver files into Samba's
[print$].</b></p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>smbclient //localhost/print\$ -U 'root%xxxx' \
-c 'cd W32X86; \
put /etc/cups/ppd/mysmbtstprn.ppd mysmbtstprn.PPD; \
put /usr/share/cups/drivers/cupsui.dll cupsui.dll; \
put /usr/share/cups/drivers/cupsdrvr.dll cupsdrvr.dll; \
put /usr/share/cups/drivers/cups.hlp cups.hlp'</code></strong>
</pre><p>
(This command should be entered in one long single line. Line breaks and the line ends indicated by
“<span class="quote">\</span>” have been inserted for readability reasons.) This step is <span class="emphasis"><em>required</em></span> for
the next one to succeed. It makes the driver files physically present in the <em class="parameter"><code>[print$]</code></em>
share. However, clients would still not be able to install them, because Samba does not yet treat them as
driver files. A client asking for the driver would still be presented with a “<span class="quote">not installed here</span>”
message.
</p></li><li><p class="title"><b>Verify where the driver files are now.</b></p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>ls -l /etc/samba/drivers/W32X86/</code></strong>
total 669
drwxr-sr-x 2 root ntadmin 532 May 25 23:08 2
drwxr-sr-x 2 root ntadmin 670 May 16 03:15 3
-rwxr--r-- 1 root ntadmin 14234 May 25 23:21 cups.hlp
-rwxr--r-- 1 root ntadmin 278380 May 25 23:21 cupsdrvr.dll
-rwxr--r-- 1 root ntadmin 215848 May 25 23:21 cupsui.dll
-rwxr--r-- 1 root ntadmin 169458 May 25 23:21 mysmbtstprn.PPD
</pre><p>
The driver files now are in the W32X86 architecture “<span class="quote">root</span>” of
<em class="parameter"><code>[print$]</code></em>.
</p></li><li><p class="title"><b>Tell Samba that these are driver files (<code class="literal">adddriver</code>).</b></p><p>
<a class="indexterm" name="id403706"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'adddriver "Windows NT x86" \
"mydrivername:cupsdrvr.dll:mysmbtstprn.PPD: \
cupsui.dll:cups.hlp:NULL:RAW:NULL"' \
localhost</code></strong>
Printer Driver mydrivername successfully installed.
</pre><p>
You cannot repeat this step if it fails. It could fail even as a result of a simple typo. It will most likely
have moved a part of the driver files into the “<span class="quote">2</span>” subdirectory. If this step fails, you need to
go back to the fourth step and repeat it before you can try this one again. In this step, you need to choose a
name for your driver. It is normally a good idea to use the same name as is used for the printer name;
however, in big installations you may use this driver for a number of printers that obviously have different
names, so the name of the driver is not fixed.
</p></li><li><p class="title"><b>Verify where the driver files are now.</b></p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>ls -l /etc/samba/drivers/W32X86/</code></strong>
total 1
drwxr-sr-x 2 root ntadmin 532 May 25 23:22 2
drwxr-sr-x 2 root ntadmin 670 May 16 03:15 3
<code class="prompt">root# </code><strong class="userinput"><code>ls -l /etc/samba/drivers/W32X86/2</code></strong>
total 5039
[....]
-rwxr--r-- 1 root ntadmin 14234 May 25 23:21 cups.hlp
-rwxr--r-- 1 root ntadmin 278380 May 13 13:53 cupsdrvr.dll
-rwxr--r-- 1 root ntadmin 215848 May 13 13:53 cupsui.dll
-rwxr--r-- 1 root ntadmin 169458 May 25 23:21 mysmbtstprn.PPD
</pre><p>
Notice how step 6 also moved the driver files to the appropriate
subdirectory. Compare this with the situation after step 5.
</p></li><li><p class="title"><b>(Optional.) Verify if Samba now recognizes the driver.</b></p><p>
<a class="indexterm" name="id403801"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'enumdrivers 3' \
localhost | grep -B2 -A5 mydrivername</code></strong>
Printer Driver Info 3:
Version: [2]
Driver Name: [mydrivername]
Architecture: [Windows NT x86]
Driver Path: [\\kde-bitshop\print$\W32X86\2\cupsdrvr.dll]
Datafile: [\\kde-bitshop\print$\W32X86\2\mysmbtstprn.PPD]
Configfile: [\\kde-bitshop\print$\W32X86\2\cupsui.dll]
Helpfile: [\\kde-bitshop\print$\W32X86\2\cups.hlp]
</pre><p>
Remember, this command greps for the name you chose for the
driver in step 6. This command must succeed before you can proceed.
</p></li><li><p><font color="red"><title>Tell Samba which printer should use these driver files (<code class="literal">setdriver</code>).</title></font></p><p>
<a class="indexterm" name="id403852"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'setdriver mysmbtstprn mydrivername' \
localhost</code></strong>
Successfully set mysmbtstprn to driver mydrivername
</pre><p>
Since you can bind any printer name (print queue) to any driver, this is a convenient way to set up many
queues that use the same driver. You do not need to repeat all the previous steps for the setdriver command to
succeed. The only preconditions are that <code class="literal">enumdrivers</code> must find the driver and
<code class="literal">enumprinters</code> must find the printer.
</p></li><li><p class="title"><b>(Optional) Verify if Samba has recognized this association.</b></p><p>
<a class="indexterm" name="id403907"></a>
<a class="indexterm" name="id403916"></a>
<a class="indexterm" name="id403926"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2' localhost \
| grep driver</code></strong>
drivername:[mydrivername]
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2' localhost \
| grep -C4 driv</code></strong>
servername:[\\kde-bitshop]
printername:[\\kde-bitshop\mysmbtstprn]
sharename:[mysmbtstprn]
portname:[Done]
drivername:[mydrivername]
comment:[mysmbtstprn]
location:[]
sepfile:[]
printprocessor:[winprint]
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -U root%xxxx -c 'getdriver mysmbtstprn' localhost</code></strong>
[Windows NT x86]
Printer Driver Info 3:
Version: [2]
Driver Name: [mydrivername]
Architecture: [Windows NT x86]
Driver Path: [\\kde-bitshop\print$\W32X86\2\cupsdrvr.dll]
Datafile: [\\kde-bitshop\print$\W32X86\2\mysmbtstprn.PPD]
Configfile: [\\kde-bitshop\print$\W32X86\2\cupsui.dll]
Helpfile: [\\kde-bitshop\print$\W32X86\2\cups.hlp]
Monitorname: []
Defaultdatatype: [RAW]
Monitorname: []
Defaultdatatype: [RAW]
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient -Uroot%xxxx -c 'enumprinters' localhost \
| grep mysmbtstprn</code></strong>
name:[\\kde-bitshop\mysmbtstprn]
description:[\\kde-bitshop\mysmbtstprn,mydrivername,mysmbtstprn]
comment:[mysmbtstprn]
</pre><p>
<a class="indexterm" name="id403993"></a>
Compare these results with the ones from steps 2 and 3. Every one of these commands show the driver is installed. Even
the <code class="literal">enumprinters</code> command now lists the driver
on the “<span class="quote">description</span>” line.
</p></li><li><p class="title"><b>(Optional.) Tickle the driver into a correct
device mode.</b></p><p>
<a class="indexterm" name="id404026"></a>
You certainly know how to install the driver on the client. In case
you are not particularly familiar with Windows, here is a short
recipe: Browse the Network Neighborhood, go to the Samba server, and look
for the shares. You should see all shared Samba printers.
Double-click on the one in question. The driver should get
installed and the network connection set up. Another way is to
open the <span class="guilabel">Printers (and Faxes)</span> folder, right-click on the printer in
question, and select <span class="guilabel">Connect</span> or <span class="guilabel">Install</span>. As a result, a new printer
should appear in your client's local <span class="guilabel">Printers (and Faxes)</span>
folder, named something like <span class="guilabel">printersharename on Sambahostname</span>.
</p><p>
It is important that you execute this step as a Samba printer admin
(as defined in <code class="filename">smb.conf</code>). Here is another method
to do this on Windows XP. It uses a command line, which you may type
into the “<span class="quote">DOS box</span>” (type root's smbpassword when prompted):
</p><pre class="screen">
<code class="prompt">C:\> </code><strong class="userinput"><code>runas /netonly /user:root "rundll32 printui.dll,PrintUIEntry \
/in /n \\sambaserver\mysmbtstprn"</code></strong>
</pre><p>
Change any printer setting once (like changing <span class="emphasis"><em><span class="guilabel">portrait</span> to
<span class="guilabel">landscape</span></em></span>), click on <span class="guibutton">Apply</span>, and change the setting back.
</p></li><li><p class="title"><b>Install the printer on a client (Point'n'Print).</b></p><p>
<a class="indexterm" name="id404135"></a>
</p><pre class="screen">
<code class="prompt">C:\> </code><strong class="userinput"><code>rundll32 printui.dll,PrintUIEntry /in /n "\\sambaserver\mysmbtstprn"</code></strong>
</pre><p>
If it does not work, it could be a permissions problem with the <em class="parameter"><code>[print$]</code></em> share.
</p></li><li><p class="title"><b>(Optional) Print a test page.</b></p><a class="indexterm" name="id404175"></a><pre class="screen">
<code class="prompt">C:\> </code><strong class="userinput"><code>rundll32 printui.dll,PrintUIEntry /p /n "\\sambaserver\mysmbtstprn"</code></strong>
</pre><p>
Then hit [TAB] five times, [ENTER] twice, [TAB] once, and [ENTER] again, and march to the printer.
</p></li><li><p class="title"><b>(Recommended.) Study the test page.</b></p><p>
Hmmm. Just kidding! By now you know everything about printer installations and you do not need to read a word.
Just put it in a frame and bolt it to the wall with the heading "MY FIRST RPCCLIENT-INSTALLED PRINTER"
why not just throw it away!
</p></li><li><p class="title"><b>(Obligatory.) Enjoy. Jump. Celebrate your success.</b></p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>echo "Cheeeeerioooooo! Success..." >> /var/log/samba/log.smbd</code></strong>
</pre></li></ol></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id404250"></a>Troubleshooting Revisited</h3></div></div></div><p>
<a class="indexterm" name="id404258"></a>
The setdriver command will fail if in Samba's mind the queue is not
already there. A successful installation displys the promising message that the:
</p><pre class="screen">
Printer Driver ABC successfully installed.
</pre><p>
following the <code class="literal">adddriver</code> parts of the procedure. But you may also see
a disappointing message like this one:
<code class="computeroutput">
result was NT_STATUS_UNSUCCESSFUL
</code></p><p>
<a class="indexterm" name="id404287"></a>
<a class="indexterm" name="id404294"></a>
It is not good enough that you can see the queue in CUPS, using the <code class="literal">lpstat -p ir85wm</code>
command. A bug in most recent versions of Samba prevents the proper update of the queue list. The recognition
of newly installed CUPS printers fails unless you restart Samba or send a HUP to all smbd processes. To verify
if this is the reason why Samba does not execute the <code class="literal">setdriver</code> command successfully, check
if Samba “<span class="quote">sees</span>” the printer:
<a class="indexterm" name="id404319"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient transmeta -N -U'root%xxxx' -c 'enumprinters 0'|grep ir85wm</code></strong>
printername:[ir85wm]
</pre><p>
An alternate command could be this:
<a class="indexterm" name="id404347"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>rpcclient transmeta -N -U'root%secret' -c 'getprinter ir85wm' </code></strong>
cmd = getprinter ir85wm
flags:[0x800000]
name:[\\transmeta\ir85wm]
description:[\\transmeta\ir85wm,ir85wm,DPD]
comment:[CUPS PostScript-Treiber for Windows NT/200x/XP]
</pre><p>
By the way, you can use these commands, plus a few more, of course, to install drivers on remote Windows NT print servers too!
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id404381"></a>The Printing <code class="filename">*.tdb</code> Files</h2></div></div></div><p>
<a class="indexterm" name="id404395"></a>
<a class="indexterm" name="id404402"></a>
<a class="indexterm" name="id404410"></a>
<a class="indexterm" name="id404419"></a>
<a class="indexterm" name="id404428"></a>
<a class="indexterm" name="id404437"></a>
<a class="indexterm" name="id404446"></a>
<a class="indexterm" name="id404455"></a>
<a class="indexterm" name="id404464"></a>
<a class="indexterm" name="id404473"></a>
<a class="indexterm" name="id404482"></a>
<a class="indexterm" name="id404491"></a>
<a class="indexterm" name="id404500"></a>
Some mystery is associated with the series of files with a tdb suffix appearing in every Samba installation.
They are <code class="filename">connections.tdb</code>, <code class="filename">printing.tdb</code>,
<code class="filename">share_info.tdb</code>, <code class="filename">ntdrivers.tdb</code>, <code class="filename">unexpected.tdb</code>,
<code class="filename">brlock.tdb</code>, <code class="filename">locking.tdb</code>, <code class="filename">ntforms.tdb</code>,
<code class="filename">messages.tdb</code> , <code class="filename">ntprinters.tdb</code>, <code class="filename">sessionid.tdb</code>,
and <code class="filename">secrets.tdb</code>. What is their purpose?
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id404580"></a>Trivial Database Files</h3></div></div></div><p>
<a class="indexterm" name="id404588"></a>
A Windows NT (print) server keeps track of all information needed to serve its duty toward its clients by
storing entries in the Windows registry. Client queries are answered by reading from the registry,
Administrator or user configuration settings that are saved by writing into the registry. Samba and UNIX
obviously do not have such a Registry. Samba instead keeps track of all client-related information in a series
of <code class="filename">*.tdb</code> files. (TDB stands for trivial data base). These are often located in
<code class="filename">/var/lib/samba/</code> or <code class="filename">/var/lock/samba/</code>. The printing-related files are
<code class="filename">ntprinters.tdb</code>, <code class="filename">printing.tdb</code>,<code class="filename">ntforms.tdb</code>, and
<code class="filename">ntdrivers.tdb</code>.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id404646"></a>Binary Format</h3></div></div></div><p>
<code class="filename">*.tdb</code> files are not human readable. They are written in a binary format. “<span class="quote">Why not
ASCII?</span>”, you may ask. “<span class="quote">After all, ASCII configuration files are a good and proven tradition on
UNIX.</span>” The reason for this design decision by the Samba Team is mainly performance. Samba needs to be
fast; it runs a separate <code class="literal">smbd</code> process for each client connection, in some environments many
thousands of them. Some of these <code class="literal">smbds</code> might need to write-access the same
<code class="filename">*.tdb</code> file <span class="emphasis"><em>at the same time</em></span>. The file format of Samba's
<code class="filename">*.tdb</code> files allows for this provision. Many smbd processes may write to the same
<code class="filename">*.tdb</code> file at the same time. This wouldn't be possible with pure ASCII files.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id404707"></a>Losing <code class="filename">*.tdb</code> Files</h3></div></div></div><p>
It is very important that all <code class="filename">*.tdb</code> files remain consistent over all write and read
accesses. However, it may happen that these files <span class="emphasis"><em>do</em></span> get corrupted. (A <code class="literal">kill -9
`pidof smbd'</code> while a write access is in progress could do the damage, as could a power interruption,
etc.). In cases of trouble, a deletion of the old printing-related <code class="filename">*.tdb</code> files may be the
only option. After that, you need to re-create all print-related setups unless you have made a backup of the
<code class="filename">*.tdb</code> files in time.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id404753"></a>Using <code class="literal">tdbbackup</code></h3></div></div></div><p>
<a class="indexterm" name="id404766"></a>
<a class="indexterm" name="id404777"></a>
Samba ships with a little utility that helps the root user of your system to backup your
<code class="filename">*.tdb</code> files. If you run it with no argument, it prints a usage message:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>tdbbackup</code></strong>
Usage: tdbbackup [options] <fname...>
Version:3.0a
-h this help message
-s suffix set the backup suffix
-v verify mode (restore if corrupt)
</pre><p>
Here is how I backed up my <code class="filename">printing.tdb</code> file:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>ls</code></strong>
. browse.dat locking.tdb ntdrivers.tdb printing.tdb
.. share_info.tdb connections.tdb messages.tdb ntforms.tdb
printing.tdbkp unexpected.tdb brlock.tdb gmon.out namelist.debug
ntprinters.tdb sessionid.tdb
<code class="prompt">root# </code><strong class="userinput"><code>tdbbackup -s .bak printing.tdb</code></strong>
printing.tdb : 135 records
<code class="prompt">root# </code><strong class="userinput"><code>ls -l printing.tdb*</code></strong>
-rw------- 1 root root 40960 May 2 03:44 printing.tdb
-rw------- 1 root root 40960 May 2 03:44 printing.tdb.bak
</pre></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id404864"></a>CUPS Print Drivers from Linuxprinting.org</h2></div></div></div><p>
<a class="indexterm" name="id404872"></a>
CUPS ships with good support for HP LaserJet-type printers. You can install the generic driver as follows:
<a class="indexterm" name="id404880"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>lpadmin -p laserjet4plus -v parallel:/dev/lp0 -E -m laserjet.ppd</code></strong>
</pre><p>
The <code class="option">-m</code> switch will retrieve the <code class="filename">laserjet.ppd</code> from the standard
repository for not-yet-installed PPDs, which CUPS typically stores in
<code class="filename">/usr/share/cups/model</code>. Alternatively, you may use <code class="option">-P /path/to/your.ppd</code>.
</p><p>
The generic <code class="filename">laserjet.ppd,</code> however, does not support every special option for every
LaserJet-compatible model. It constitutes a sort of “<span class="quote">least common denominator</span>” of all the models.
If for some reason you must pay for the commercially available ESP Print Pro drivers, your first move should
be to consult the database on the <a href="http://www.linuxprinting.org/printer_list.cgi" target="_top">Linuxprinting</a> Web site. Linuxprinting.org has
excellent recommendations about which driver is best used for each printer. Its database is kept current by
the tireless work of Till Kamppeter from Mandrakesoft, who is also the principal author of the
<code class="literal">foomatic-rip</code> utility.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id404961"></a>
<a class="indexterm" name="id404967"></a>
<a class="indexterm" name="id404974"></a>
The former <code class="literal">cupsomatic</code> concept is now being replaced by the new successor, a much more
powerful <code class="literal">foomatic-rip</code>. <code class="literal">cupsomatic</code> is no longer maintained. Here is the
new URL to the <a href="http://www.linuxprinting.org/driver_list.cgi" target="_top">Foomatic-3.0</a>
database. If you upgrade to <code class="literal">foomatic-rip</code>, remember to also upgrade to the new-style PPDs
for your Foomatic-driven printers. foomatic-rip will not work with PPDs generated for the old
<code class="literal">cupsomatic</code>. The new-style PPDs are 100% compliant with the Adobe PPD specification. They
are also intended to be used by Samba and the cupsaddsmb utility, to provide the driver files for the Windows
clients!
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id405024"></a>foomatic-rip and Foomatic Explained</h3></div></div></div><p>
<a class="indexterm" name="id405032"></a>
<a class="indexterm" name="id405039"></a>
Nowadays, most Linux distributions rely on the utilities from the <a href="http://www.linuxprinting.org/" target="_top">Linuxprinting.org</a> to create their printing-related software
(which, by the way, works on all UNIXes and on Mac OS X and Darwin, too). The utilities from this sire have a
very end-user-friendly interface that allows for an easy update of drivers and PPDs for all supported models,
all spoolers, all operating systems, and all package formats (because there is none). Its history goes back a
few years.
</p><p>
Recently, Foomatic has achieved the astonishing milestone of <a href="http://www.linuxprinting.org/printer_list.cgi?make=Anyone" target="_top">1,000 listed</a> printer models.
Linuxprinting.org keeps all the important facts about printer drivers, supported models, and which options are
available for the various driver/printer combinations in its <a href="http://www.linuxprinting.org/foomatic.html" target="_top">Foomatic</a> database. Currently there are <a href="http://www.linuxprinting.org/driver_list.cgi" target="_top">245 drivers</a> in the database. Many drivers support
various models, and many models may be driven by different drivers its your choice!
</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405085"></a>690 “<span class="quote">Perfect</span>” Printers</h4></div></div></div><p>
<a class="indexterm" name="id405096"></a>
At present, there are 690 devices dubbed as working perfectly: 181 are <span class="emphasis"><em>mostly</em></span> perfect, 96
are <span class="emphasis"><em>partially</em></span> perfect, and 46 are paperweights. Keeping in mind that most of these are
non-PostScript models (PostScript printers are automatically supported by CUPS to perfection by using their
own manufacturer-provided Windows PPD), and that a multifunctional device never qualifies as working perfectly
if it does not also scan and copy and fax under GNU/Linux then this is a truly astonishing
achievement! Three years ago the number was not more than 500, and Linux or UNIX printing at the time wasn't
anywhere near the quality it is today.
</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405121"></a>How the Printing HOWTO Started It All</h4></div></div></div><p>
A few years ago <a href="http://www2.picante.com/" target="_top">Grant Taylor</a> started it all. The
roots of today's Linuxprinting.org are in the first <a href="http://www.linuxprinting.org/foomatic2.9/howto/" target="_top">Linux Printing HOWTO</a> that he authored. As a
side-project to this document, which served many Linux users and admins to guide their first steps in this
complicated and delicate setup (to a scientist, printing is “<span class="quote">applying a structured deposition of
distinct patterns of ink or toner particles on paper substrates</span>”), he started to build in a little
Postgres database with information about the hardware and driver zoo that made up Linux printing of the time.
This database became the core component of today's Foomatic collection of tools and data. In the meantime, it
has moved to an XML representation of the data.
</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405151"></a>Foomatic's Strange Name</h4></div></div></div><p>
<a class="indexterm" name="id405159"></a>
“<span class="quote">Why the funny name?</span>” you ask. When it really took off, around spring 2000, CUPS was far less
popular than today, and most systems used LPD, LPRng, or even PDQ to print. CUPS shipped with a few generic
drivers (good for a few hundred different printer models). These didn't support many device-specific options.
CUPS also shipped with its own built-in rasterization filter (<em class="parameter"><code>pstoraster</code></em>, derived from
Ghostscript). On the other hand, CUPS provided brilliant support for <span class="emphasis"><em>controlling</em></span> all
printer options through standardized and well-defined PPD files. Plus, CUPS was designed to be easily
extensible.
</p><p>
Taylor already had in his database a respectable compilation of facts about many more printers and the
Ghostscript “<span class="quote">drivers</span>” they run with. His idea, to generate PPDs from the database information and
use them to make standard Ghostscript filters work within CUPS, proved to work very well. It also killed
several birds with one stone:
</p><div class="itemizedlist"><ul type="disc"><li><p>It made all current and future Ghostscript filter
developments available for CUPS.</p></li><li><p>It made available a lot of additional printer models
to CUPS users (because often the traditional Ghostscript way of
printing was the only one available).</p></li><li><p>It gave all the advanced CUPS options (Web interface,
GUI driver configurations) to users wanting (or needing) to use
Ghostscript filters.</p></li></ul></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405215"></a>cupsomatic, pdqomatic, lpdomatic, directomatic</h4></div></div></div><p>
<a class="indexterm" name="id405223"></a>
<a class="indexterm" name="id405230"></a>
<a class="indexterm" name="id405237"></a>
CUPS worked through a quickly hacked-up filter script named <a href="http://www.linuxprinting.org/download.cgi?filename=cupsomatic&show=0" target="_top">cupsomatic</a>. cupsomatic
ran the printfile through Ghostscript, constructing automatically the rather complicated command line needed.
It just needed to be copied into the CUPS system to make it work. To configure the way cupsomatic controls the
Ghostscript rendering process, it needs a CUPS-PPD. This PPD is generated directly from the contents of the
database. For CUPS and the respective printer/filter combo, another Perl script named CUPS-O-Matic did the PPD
generation. After that was working, Taylor implemented within a few days a similar thing for two other
spoolers. Names chosen for the config-generator scripts were <a href="http://www.linuxprinting.org/download.cgi?filename=lpdomatic&show=0" target="_top">PDQ-O-Matic</a> (for PDQ)
and <a href="http://www.linuxprinting.org/download.cgi?filename=lpdomatic&show=0" target="_top">LPD-O-Matic</a>
(for you guessed it LPD); the configuration here didn't use PPDs but other
spooler-specific files.
</p><p>
From late summer of that year, <a href="http://www.linuxprinting.org/till/" target="_top">Till Kamppeter</a> started
to put work into the database. Kamppeter had been newly employed by <a href="http://www.mandrakesoft.com/" target="_top">Mandrakesoft</a> to convert its printing system over to CUPS, after
they had seen his <a href="http://www.fltk.org/" target="_top">FLTK</a>-based <a href="http://cups.sourceforge.net/xpp/" target="_top">XPP</a> (a GUI front-end to the CUPS lp-command). He added a huge
amount of new information and new printers. He also developed the support for other spoolers, like <a href="http://ppr.sourceforge.net/" target="_top">PPR</a> (via ppromatic), <a href="http://sourceforge.net/projects/lpr/" target="_top">GNUlpr</a>, and <a href="http://www.lprng.org/" target="_top">LPRng</a> (both via an extended lpdomatic) and spooler-less printing (<a href="http://www.linuxprinting.org/download.cgi?filename=directomatic&show=0" target="_top">directomatic</a>).
</p><p>
So, to answer your question, “<span class="quote">Foomatic</span>” is the general name for all the overlapping code and data
behind the “<span class="quote">*omatic</span>” scripts. Foomatic, up to versions 2.0.x, required (ugly) Perl data
structures attached to Linuxprinting.org PPDs for CUPS. It had a different “<span class="quote">*omatic</span>” script for
every spooler, as well as different printer configuration files.
</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405353"></a>The <span class="emphasis"><em>Grand Unification</em></span> Achieved</h4></div></div></div><p>
<a class="indexterm" name="id405364"></a>
This has all changed in Foomatic versions 2.9 (beta) and released as “<span class="quote">stable</span>” 3.0. It has now
achieved the convergence of all *omatic scripts and is called the <a href="http://www.linuxprinting.org/foomatic2.9/download.cgi?filename=foomatic-rip&show=0" target="_top">foomatic-rip</a>.
This single script is the unification of the previously different spooler-specific *omatic scripts.
foomatic-rip is used by all the different spoolers alike, and because it can read PPDs (both the original
PostScript printer PPDs and the Linuxprinting.org-generated ones), all of a sudden all supported spoolers can
have the power of PPDs at their disposal. Users only need to plug foomatic-rip into their system. For users
there is improved media type and source support paper sizes and trays are easier to configure.
</p><p>
<a class="indexterm" name="id405393"></a>
<a class="indexterm" name="id405400"></a>
<a class="indexterm" name="id405406"></a>
Also, the new generation of Linuxprinting.org PPDs no longer contains Perl data structures. If you are a
distro maintainer and have used the previous version of Foomatic, you may want to give the new one a spin, but
remember to generate a new-version set of PPDs via the new <a href="http://www.linuxprinting.org/download/foomatic/foomatic-db-engine-3.0.0beta1.tar.gz" target="_top">foomatic-db-engine!</a>.
Individual users just need to generate a single new PPD specific to their model by <a href="http://www.linuxprinting.org/kpfeifle/LinuxKongress2002/Tutorial/II.Foomatic-User/II.tutorial-handout-foomatic-user.html" target="_top">following
the steps</a> outlined in the Foomatic tutorial or in this chapter. This new development is truly amazing.
</p><p>
<a class="indexterm" name="id405433"></a>
<a class="indexterm" name="id405440"></a>
<a class="indexterm" name="id405447"></a>
foomatic-rip is a very clever wrapper around the need to run Ghostscript with a different syntax, options,
device selections, and/or filters for each different printer or spooler. At the same time, it can read the PPD
associated with a print queue and modify the print job according to the user selections. Together with this
comes the 100% compliance of the new Foomatic PPDs with the Adobe spec. Some innovative features of the
Foomatic concept may surprise users. It will support custom paper sizes for many printers and will support
printing on media drawn from different paper trays within the same job (in both cases, even where there is no
support for this from Windows-based vendor printer drivers).
</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405462"></a>Driver Development Outside</h4></div></div></div><p>
<a class="indexterm" name="id405470"></a>
Most driver development itself does not happen within Linuxprinting.org. Drivers are written by independent
maintainers. Linuxprinting.org just pools all the information and stores it in its database. In addition, it
also provides the Foomatic glue to integrate the many drivers into any modern (or legacy) printing system
known to the world.
</p><p>
Speaking of the different driver development groups, most of the work is currently done in three projects:
</p><div class="itemizedlist"><ul type="disc"><li><p>
<a class="indexterm" name="id405490"></a>
<a href="http://www-124.ibm.com/developerworks/oss/linux/projects/omni/" target="_top">Omni</a>
a free software project by IBM that tries to convert its printer
driver knowledge from good-ol' OS/2 times into a modern, modular,
universal driver architecture for Linux/UNIX (still beta). This
currently supports 437 models.</p></li><li><p>
<a class="indexterm" name="id405513"></a>
<a href="http://hpinkjet.sf.net/" target="_top">HPIJS</a>
a free software project by HP to provide the support for its own
range of models (very mature, printing in most cases is perfect and
provides true photo quality). This currently supports 369
models.</p></li><li><p>
<a class="indexterm" name="id405534"></a>
<a href="http://gimp-print.sf.net/" target="_top">Gimp-Print</a> a free software
effort, started by Michael Sweet (also lead developer for CUPS), now
directed by Robert Krawitz, which has achieved an amazing level of
photo print quality (many Epson users swear that its quality is
better than the vendor drivers provided by Epson for the Microsoft
platforms). This currently supports 522 models.</p></li></ul></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405555"></a>Forums, Downloads, Tutorials, Howtos (Also for Mac OS X and Commercial UNIX)</h4></div></div></div><p>
Linuxprinting.org today is the one-stop shop to download printer drivers. Look for printer information and
<a href="http://www.linuxprinting.org//kpfeifle/LinuxKongress2002/Tutorial/" target="_top">tutorials</a> or solve
printing problems in its popular <a href="http://www.linuxprinting.org/newsportal/" target="_top">forums</a>. This
forum is not just for GNU/Linux users, but admins of <a href="http://www.linuxprinting.org/macosx/" target="_top">
commercial UNIX systems</a> are also going there, and the relatively new
<a href="http://www.linuxprinting.org/newsportal/thread.php3?name=linuxprinting.macosx.general" target="_top">Mac OS X
forum</a> has turned out to be one of the most frequented forums after only a few weeks.
</p><p>
<a class="indexterm" name="id405594"></a>
<a class="indexterm" name="id405601"></a>
<a class="indexterm" name="id405607"></a>
Linuxprinting.org and the Foomatic driver wrappers around Ghostscript are now a standard tool-chain for
printing on all the important distros. Most of them also have CUPS underneath. While in recent years most
printer data had been added by Kamppeter, many additional contributions came from engineers with SuSE, Red
Hat, Conectiva, Debian, and others. Vendor-neutrality is an important goal of the Foomatic project. Mandrake
and Conectiva have merged and are now called Mandriva.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
Till Kamppeter from Mandrakesoft is doing an excellent job in his spare time to maintain Linuxprinting.org and
Foomatic. So if you use it often, please send him a note showing your appreciation.
</p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id405626"></a>Foomatic Database-Generated PPDs</h4></div></div></div><p>
<a class="indexterm" name="id405634"></a>
<a class="indexterm" name="id405641"></a>
<a class="indexterm" name="id405648"></a>
<a class="indexterm" name="id405655"></a>
<a class="indexterm" name="id405662"></a>
<a class="indexterm" name="id405668"></a>
<a class="indexterm" name="id405675"></a>
<a class="indexterm" name="id405682"></a>
<a class="indexterm" name="id405689"></a>
The Foomatic database is an amazing piece of ingenuity in itself. Not only does it keep the printer and driver
information, but it is organized in a way that it can generate PPD files on the fly from its internal
XML-based datasets. While these PPDs are modeled to the Adobe specification of PPDs, the
Linuxprinting.org/Foomatic-PPDs do not normally drive PostScript printers. They are used to describe all the
bells and whistles you could ring or blow on an Epson Stylus inkjet, or an HP Photosmart, or what-have-you.
The main trick is one little additional line, not envisaged by the PPD specification, starting with the
<em class="parameter"><code>*cupsFilter</code></em> keyword. It tells the CUPS daemon how to proceed with the PostScript print
file (old-style Foomatic-PPDs named the cupsomatic filter script, while the new-style PPDs are now call
foomatic-rip). This filter script calls Ghostscript on the host system (the recommended variant is ESP
Ghostscript) to do the rendering work. foomatic-rip knows which filter or internal device setting it should
ask from Ghostscript to convert the PostScript print job into a raster format ready for the target device.
This usage of PPDs to describe the options of non-PostScript printers was the invention of the CUPS
developers. The rest is easy. GUI tools (like KDE's marvelous <a href="http://printing.kde.org/overview/kprinter.phtml" target="_top">kprinter</a> or the GNOME <a href="http://gtklp.sourceforge.net/" target="_top">gtklp</a> xpp and the CUPS Web interface) read the PPD as well and use
this information to present the available settings to the user as an intuitive menu selection.
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id405729"></a>foomatic-rip and Foomatic PPD Download and Installation</h3></div></div></div><p>
Here are the steps to install a foomatic-rip-driven LaserJet 4 Plus-compatible
printer in CUPS (note that recent distributions of SuSE, UnitedLinux and
Mandrake may ship with a complete package of Foomatic-PPDs plus the
<code class="literal">foomatic-rip</code> utility. Going directly to
Linuxprinting.org ensures that you get the latest driver/PPD files).
</p><div class="itemizedlist"><ul type="disc"><li><p>Open your browser at the Linuxprinting.org printer list <a href="http://www.linuxprinting.org/printer_list.cgi" target="_top">page.</a>
</p></li><li><p>Check the complete list of printers in the
<a href="http://www.linuxprinting.org/printer_list.cgi?make=Anyone" target="_top">database.</a>.
</p></li><li><p>Select your model and click on the link.
</p></li><li><p>You'll arrive at a page listing all drivers working with this
model (for all printers, there will always be <span class="emphasis"><em>one</em></span>
recommended driver. Try this one first).
</p></li><li><p>In our case (HP LaserJet 4 Plus), we'll arrive at the default driver for the
<a href="http://www.linuxprinting.org/show_printer.cgi?recnum=HP-LaserJet_4_Plus" target="_top">HP-LaserJet 4 Plus.</a>
</p></li><li><p>The recommended driver is ljet4.</p></li><li><p>Several links are provided here. You should visit them all if you
are not familiar with the Linuxprinting.org database.
</p></li><li><p>There is a link to the database page for the
<a href="http://www.linuxprinting.org/show_driver.cgi?driver=ljet4" target="_top">ljet4</a>.
On the driver's page, you'll find important and detailed information
about how to use that driver within the various available
spoolers.</p></li><li><p>Another link may lead you to the home page of the
author of the driver.</p></li><li><p>Important links are the ones that provide hints with
setup instructions for <a href="http://www.linuxprinting.org/cups-doc.html" target="_top">CUPS</a>;
<a href="http://www.linuxprinting.org/pdq-doc.html" target="_top">PDQ</a>;
<a href="http://www.linuxprinting.org/lpd-doc.html" target="_top">LPD, LPRng, and GNUlpr</a>);
as well as <a href="http://www.linuxprinting.org/ppr-doc.html" target="_top">PPR</a>
or “<span class="quote">spoolerless</span>” <a href="http://www.linuxprinting.org/direct-doc.html" target="_top">printing</a>.
</p></li><li><p>You can view the PPD in your browser through this link:
<a href="http://www.linuxprinting.org/ppd-o-matic.cgi?driver=ljet4&printer=HP-LaserJet_4_Plus&show=1" target="_top">http://www.linuxprinting.org/ppd-o-matic.cgi?driver=ljet4&printer=HP-LaserJet_4_Plus&show=1</a>
</p></li><li><p>Most importantly, you can also generate and download
the <a href="http://www.linuxprinting.org/ppd-o-matic.cgi?driver=ljet4&printer=HP-LaserJet_4_Plus&show=0" target="_top">PPD</a>.
</p></li><li><p>The PPD contains all the information needed to use our
model and the driver; once installed, this works transparently
for the user. Later you'll only need to choose resolution, paper size,
and so on, from the Web-based menu, or from the print dialog GUI, or from
the command line.</p></li><li><p>If you ended up on the drivers
<a href="http://www.linuxprinting.org/show_driver.cgi?driver=ljet4" target="_top">page</a>,
you can choose to use the “<span class="quote">PPD-O-Matic</span>” online PPD generator
program.</p></li><li><p>Select the exact model and check either <span class="guilabel">Download</span> or
<span class="guilabel">Display PPD file</span> and click <span class="guilabel">Generate PPD file</span>.</p></li><li><p>If you save the PPD file from the browser view, please
do not use cut and paste (since it could possibly damage line endings
and tabs, which makes the PPD likely to fail its duty), but use <span class="guimenuitem">Save
as...</span> in your browser's menu. (It is best to use the <span class="guilabel">Download</span> option
directly from the Web page.)</p></li><li><p>Another interesting part on each driver page is
the <span class="guimenuitem">Show execution details</span> button. If you
select your printer model and click on that button,
a complete Ghostscript command line will be displayed, enumerating all options
available for that combination of driver and printer model. This is a great way to
“<span class="quote">learn Ghostscript by doing</span>”. It is also an excellent cheat sheet
for all experienced users who need to reconstruct a good command line
for that darned printing script, but can't remember the exact
syntax. </p></li><li><p>Sometime during your visit to Linuxprinting.org, save
the PPD to a suitable place on your hard disk, say
<code class="filename">/path/to/my-printer.ppd</code> (if you prefer to install
your printers with the help of the CUPS Web interface, save the PPD to
the <code class="filename">/usr/share/cups/model/</code> path and restart
cupsd).</p></li><li><p>Then install the printer with a suitable command line,
like this:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>lpadmin -p laserjet4plus -v parallel:/dev/lp0 -E \
-P path/to/my-printer.ppd</code></strong>
</pre></li><li><p>For all the new-style “<span class="quote">Foomatic-PPDs</span>”
from Linuxprinting.org, you also need a special CUPS filter named
foomatic-rip.
</p></li><li><p>The foomatic-rip Perl script itself also makes some
interesting <a href="http://www.linuxprinting.org/foomatic2.9/download.cgi?filename=foomatic-rip&show=1" target="_top">reading</a>
because it is well documented by Kamppeter's in-line comments (even
non-Perl hackers will learn quite a bit about printing by reading
it).</p></li><li><p>Save foomatic-rip either directly in
<code class="filename">/usr/lib/cups/filter/foomatic-rip</code> or somewhere in
your $PATH (and remember to make it world-executable). Again,
do not save by copy and paste but use the appropriate link or the
<span class="guimenuitem">Save as...</span> menu item in your browser.</p></li><li><p>If you save foomatic-rip in your $PATH, create a symlink:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>cd /usr/lib/cups/filter/ ; ln -s `which foomatic-rip'</code></strong>
</pre><p>
</p><p>
CUPS will discover this new available filter at startup after restarting
cupsd.</p></li></ul></div><p>
Once you print to a print queue set up with the Foomatic PPD, CUPS will insert the appropriate commands and
comments into the resulting PostScript job file. foomatic-rip is able to read and act upon these and uses some
specially encoded Foomatic comments embedded in the job file. These in turn are used to construct
(transparently for you, the user) the complicated Ghostscript command line telling the printer driver exactly
how the resulting raster data should look and which printer commands to embed into the data stream. You need:
</p><div class="itemizedlist"><ul type="disc"><li><p>A “<span class="quote">foomatic+something</span>” PPD but this is not enough
to print with CUPS (it is only <span class="emphasis"><em>one</em></span> important
component).</p></li><li><p>The <em class="parameter"><code>foomatic-rip</code></em> filter script (Perl) in
<code class="filename">/usr/lib/cups/filters/</code>.</p></li><li><p>Perl to make foomatic-rip run.</p></li><li><p>Ghostscript (because it is doing the main work,
controlled by the PPD/foomatic-rip combo) to produce the raster data
fit for your printer model's consumption.</p></li><li><p>Ghostscript <span class="emphasis"><em>must</em></span> (depending on
the driver/model) contain support for a certain device representing
the selected driver for your model (as shown by <code class="literal">gs -h</code>).</p></li><li><p>foomatic-rip needs a new version of PPDs (PPD versions
produced for cupsomatic do not work with foomatic-rip).</p></li></ul></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id406151"></a>Page Accounting with CUPS</h2></div></div></div><p>
<a class="indexterm" name="id406159"></a>
Often there are questions regarding print quotas where Samba users (that is, Windows clients) should not be
able to print beyond a certain number of pages or data volume per day, week, or month. This feature is
dependent on the real print subsystem you're using. Samba's part is always to receive the job files from the
clients (filtered <span class="emphasis"><em>or</em></span> unfiltered) and hand them over to this printing subsystem.
</p><p>
Of course one could hack things with one's own scripts. But then there is CUPS. CUPS supports quotas that can
be based on the size of jobs or on the number of pages or both, and can span any time period you want.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406181"></a>Setting Up Quotas</h3></div></div></div><p>
<a class="indexterm" name="id406189"></a>
This is an example command of how root would set a print quota in CUPS, assuming an existing printer named
“<span class="quote">quotaprinter</span>”:
<a class="indexterm" name="id406203"></a>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>lpadmin -p quotaprinter -o job-quota-period=604800 \
-o job-k-limit=1024 -o job-page-limit=100</code></strong>
</pre><p>
This would limit every single user to print no more than 100 pages or 1024 KB of
data (whichever comes first) within the last 604,800 seconds ( = 1 week).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406232"></a>Correct and Incorrect Accounting</h3></div></div></div><p>
For CUPS to count correctly, the printfile needs to pass the CUPS pstops filter; otherwise it uses a dummy
count of “<span class="quote">one</span>”. Some print files do not pass it (e.g., image files), but then those are mostly
one-page jobs anyway. This also means that proprietary drivers for the target printer running on the client
computers and CUPS/Samba, which then spool these files as “<span class="quote">raw</span>” (i.e., leaving them untouched,
not filtering them), will be counted as one-pagers too!
</p><p>
You need to send PostScript from the clients (i.e., run a PostScript driver there) to have the chance to get
accounting done. If the printer is a non-PostScript model, you need to let CUPS do the job to convert the file
to a print-ready format for the target printer. This is currently working for about a thousand different
printer models. Linuxprinting.org has a driver <a href="http://www.linuxprinting.org/printer_list.cgi" target="_top">list</a>.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406265"></a>Adobe and CUPS PostScript Drivers for Windows Clients</h3></div></div></div><p>
<a class="indexterm" name="id406273"></a>
<a class="indexterm" name="id406279"></a>
<a class="indexterm" name="id406286"></a>
<a class="indexterm" name="id406293"></a>
<a class="indexterm" name="id406300"></a>
Before CUPS 1.1.16, your only option was to use the Adobe PostScript driver on the Windows clients. The output
of this driver was not always passed through the <code class="literal">pstops</code> filter on the CUPS/Samba side, and
therefore was not counted correctly (the reason is that it often, depending on the PPD being used, wrote a
PJL-header in front of the real PostScript, which caused CUPS to skip <code class="literal">pstops</code> and go
directly to the <code class="literal">pstoraster</code> stage).
</p><p>
From CUPS 1.1.16 and later releases, you can use the CUPS PostScript driver for Windows NT/200x/XP
clients (which is tagged in the download area of <code class="filename">http://www.cups.org/</code> as the
<code class="filename">cups-samba-1.1.16.tar.gz</code> package). It does <span class="emphasis"><em>not</em></span> work for Windows
9x/Me clients, but it guarantees:
</p><div class="itemizedlist"><ul type="disc"><li><p> <a class="indexterm" name="id406354"></a> To not write a PJL-header.</p></li><li><p>To still read and support all PJL-options named in the
driver PPD with its own means.</p></li><li><p>That the file will pass through the <code class="literal">pstops</code> filter
on the CUPS/Samba server.</p></li><li><p>To page-count correctly the print file.</p></li></ul></div><p>
You can read more about the setup of this combination in the man page for <code class="literal">cupsaddsmb</code> (which
is only present with CUPS installed, and only current from CUPS 1.1.16).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406396"></a>The page_log File Syntax</h3></div></div></div><p>
<a class="indexterm" name="id406403"></a>
These are the items CUPS logs in the <code class="filename">page_log</code> for every page of a job:
</p><div class="itemizedlist"><ul type="disc"><li><p>Printer name</p></li><li><p>User name</p></li><li><p>Job ID</p></li><li><p>Time of printing</p></li><li><p>Page number</p></li><li><p>Number of copies</p></li><li><p>A billing information string (optional)</p></li><li><p>The host that sent the job (included since version 1.1.19)</p></li></ul></div><p>
Here is an extract of my CUPS server's <code class="filename">page_log</code> file to illustrate the
format and included items:
</p><pre class="screen">
tec_IS2027 kurt 401 [22/Apr/2003:10:28:43 +0100] 1 3 #marketing 10.160.50.13
tec_IS2027 kurt 401 [22/Apr/2003:10:28:43 +0100] 2 3 #marketing 10.160.50.13
tec_IS2027 kurt 401 [22/Apr/2003:10:28:43 +0100] 3 3 #marketing 10.160.50.13
tec_IS2027 kurt 401 [22/Apr/2003:10:28:43 +0100] 4 3 #marketing 10.160.50.13
Dig9110 boss 402 [22/Apr/2003:10:33:22 +0100] 1 440 finance-dep 10.160.51.33
</pre><p>
This was job ID <em class="parameter"><code>401</code></em>, printed on <em class="parameter"><code>tec_IS2027</code></em>
by user <em class="parameter"><code>kurt</code></em>, a 64-page job printed in three copies, billed to
<em class="parameter"><code>#marketing</code></em>, and sent from IP address <code class="constant">10.160.50.13.</code>
The next job had ID <em class="parameter"><code>402</code></em>, was sent by user <em class="parameter"><code>boss</code></em>
from IP address <code class="constant">10.160.51.33</code>, printed from one page 440 copies, and
is set to be billed to <em class="parameter"><code>finance-dep</code></em>.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406532"></a>Possible Shortcomings</h3></div></div></div><p>
What flaws or shortcomings are there with this quota system?
</p><div class="itemizedlist"><ul type="disc"><li><p>The ones named above (wrongly logged job in case of
printer hardware failure, and so on).</p></li><li><p>In reality, CUPS counts the job pages that are being
processed in <span class="emphasis"><em>software</em></span> (that is, going through the
RIP) rather than the physical sheets successfully leaving the
printing device. Thus, if there is a jam while printing the fifth sheet out
of 1,000 and the job is aborted by the printer, the page count will
still show the figure of 1,000 for that job.</p></li><li><p>All quotas are the same for all users (no flexibility
to give the boss a higher quota than the clerk) and no support for
groups.</p></li><li><p>No means to read out the current balance or the
“<span class="quote">used-up</span>” number of current quota.</p></li><li><p>A user having used up 99 sheets of a 100 quota will
still be able to send and print a 1,000 sheet job.</p></li><li><p>A user being denied a job because of a filled-up quota
does not get a meaningful error message from CUPS other than
“<span class="quote">client-error-not-possible</span>”.</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406590"></a>Future Developments</h3></div></div></div><p>
This is the best system currently available, and there are huge
improvements under development for CUPS 1.2:
</p><div class="itemizedlist"><ul type="disc"><li><p>Page counting will go into the backends (these talk
directly to the printer and will increase the count in sync with the
actual printing process; thus, a jam at the fifth sheet will lead to a
stop in the counting).</p></li><li><p>Quotas will be handled more flexibly.</p></li><li><p>Probably there will be support for users to inquire
about their accounts in advance.</p></li><li><p>Probably there will be support for some other tools
around this topic.</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406625"></a>Other Accounting Tools</h3></div></div></div><p>
Other accounting tools that can be used includes: PrintAnalyzer, pyKota, printbill, LogReport.
For more information regarding these tools you can try a Google search.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id406637"></a>Additional Material</h2></div></div></div><p>
A printer queue with <span class="emphasis"><em>no</em></span> PPD associated to it is a
“<span class="quote">raw</span>” printer, and all files will go directly there as received by the
spooler. The exceptions are file types <em class="parameter"><code>application/octet-stream</code></em>
that need the pass-through feature enabled. “<span class="quote">Raw</span>” queues do not do any
filtering at all; they hand the file directly to the CUPS backend.
This backend is responsible for sending the data to the device
(as in the “<span class="quote">device URI</span>” notation: <code class="filename">lpd://, socket://,
smb://, ipp://, http://, parallel:/, serial:/, usb:/</code>, and so on).
</p><p>
cupsomatic/Foomatic are <span class="emphasis"><em>not</em></span> native CUPS drivers
and they do not ship with CUPS. They are a third-party add-on
developed at Linuxprinting.org. As such, they are a brilliant hack to
make all models (driven by Ghostscript drivers/filters in traditional
spoolers) also work via CUPS, with the same (good or bad!) quality as
in these other spoolers. <em class="parameter"><code>cupsomatic</code></em> is only a vehicle to execute a
Ghostscript command line at that stage in the CUPS filtering chain
where normally the native CUPS <em class="parameter"><code>pstoraster</code></em> filter would kick
in. <em class="parameter"><code>cupsomatic</code></em> bypasses <em class="parameter"><code>pstoraster</code></em>, kidnaps the print file from CUPS,
and redirects it to go through Ghostscript. CUPS accepts this
because the associated cupsomatic/foomatic-PPD specifies:
</p><pre class="programlisting">
*cupsFilter: "application/vnd.cups-postscript 0 cupsomatic"
</pre><p>
This line persuades CUPS to hand the file to <em class="parameter"><code>cupsomatic</code></em> once it has
successfully converted it to the MIME type
<em class="parameter"><code>application/vnd.cups-postscript</code></em>. This conversion will not happen for
jobs arriving from Windows that are autotyped
<em class="parameter"><code>application/octet-stream</code></em>, with the according changes in
<code class="filename">/etc/cups/mime.types</code> in place.
</p><p>
CUPS is widely configurable and flexible, even regarding its filtering
mechanism. Another workaround in some situations would be to have in
<code class="filename">/etc/cups/mime.types</code> entries as follows:
</p><pre class="programlisting">
application/postscript application/vnd.cups-raw 0 -
application/vnd.cups-postscript application/vnd.cups-raw 0 -
</pre><p>
This would prevent all PostScript files from being filtered (rather,
they will through the virtual <span class="emphasis"><em>nullfilter</em></span>
denoted with “<span class="quote">-</span>”). This could only be useful for PostScript printers. If you
want to print PostScript code on non-PostScript printers (provided they support ASCII
text printing), an entry as follows could be useful:
</p><pre class="programlisting">
*/* application/vnd.cups-raw 0 -
</pre><p>
and would effectively send <span class="emphasis"><em>all</em></span> files to the
backend without further processing.
</p><p>
You could have the following entry:
</p><pre class="programlisting">
application/vnd.cups-postscript application/vnd.cups-raw 0 \
my_PJL_stripping_filter
</pre><p>
You will need to write a <em class="parameter"><code>my_PJL_stripping_filter</code></em>
(which could be a shell script) that parses the PostScript and removes the
unwanted PJL. This needs to conform to CUPS filter design
(mainly, receive and pass the parameters printername, job-id,
username, jobtitle, copies, print options, and possibly the
filename). It is installed as world executable into
<code class="filename">/usr/lib/cups/filters/</code> and is called by CUPS
if it encounters a MIME type <em class="parameter"><code>application/vnd.cups-postscript</code></em>.
</p><p>
CUPS can handle <em class="parameter"><code>-o job-hold-until=indefinite</code></em>.
This keeps the job in the queue on hold. It will only be printed
upon manual release by the printer operator. This is a requirement in
many central reproduction departments, where a few operators manage
the jobs of hundreds of users on some big machine, where no user is
allowed to have direct access (such as when the operators often need
to load the proper paper type before running the 10,000 page job
requested by marketing for the mailing, and so on).
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id406826"></a>Autodeletion or Preservation of CUPS Spool Files</h2></div></div></div><p>
<a class="indexterm" name="id406834"></a>
<a class="indexterm" name="id406840"></a>
<a class="indexterm" name="id406847"></a>
Samba print files pass through two spool directories. One is the incoming directory managed by Samba (set in
the <a class="indexterm" name="id406855"></a>path = /var/spool/samba directive in the <em class="parameter"><code>[printers]</code></em> section of <code class="filename">smb.conf</code>). The other is the spool directory of your UNIX print subsystem. For
CUPS it is normally <code class="filename">/var/spool/cups/</code>, as set by the <code class="filename">cupsd.conf</code>
directive <code class="filename">RequestRoot /var/spool/cups</code>.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406894"></a>CUPS Configuration Settings Explained</h3></div></div></div><p>
Some important parameter settings in the CUPS configuration file
<code class="filename">cupsd.conf</code> are:
</p><div class="variablelist"><dl><dt><span class="term">PreserveJobHistory Yes</span></dt><dd><p>
This keeps some details of jobs in cupsd's mind (well, it keeps the
c12345, c12346, and so on, files in the CUPS spool directory, which does a
similar job as the old-fashioned BSD-LPD control files). This is set
to “<span class="quote">Yes</span>” as a default.
</p></dd><dt><span class="term">PreserveJobFiles Yes</span></dt><dd><p>
This keeps the job files themselves in cupsd's mind
(it keeps the d12345, d12346, etc., files in the CUPS spool
directory). This is set to “<span class="quote">No</span>” as the CUPS
default.
</p></dd><dt><span class="term">“<span class="quote">MaxJobs 500</span>”</span></dt><dd><p>
This directive controls the maximum number of jobs
that are kept in memory. Once the number of jobs reaches the limit,
the oldest completed job is automatically purged from the system to
make room for the new one. If all of the known jobs are still
pending or active, then the new job will be rejected. Setting the
maximum to 0 disables this functionality. The default setting is
0.
</p></dd></dl></div><p>
(There are also additional settings for <em class="parameter"><code>MaxJobsPerUser</code></em> and
<em class="parameter"><code>MaxJobsPerPrinter</code></em>.)
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id406971"></a>Preconditions</h3></div></div></div><p>
For everything to work as it should, you need to have three things:
</p><div class="itemizedlist"><ul type="disc"><li><p>A Samba smbd that is compiled against <code class="filename">libcups</code> (check
on Linux by running <strong class="userinput"><code>ldd `which smbd'</code></strong>).</p></li><li><p>A Samba-<code class="filename">smb.conf</code> setting of
<a class="indexterm" name="id407008"></a>printing = cups.</p></li><li><p>Another Samba <code class="filename">smb.conf</code> setting of
<a class="indexterm" name="id407026"></a>printcap = cups.</p></li></ul></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
In this case, all other manually set printing-related commands (like
<a class="indexterm" name="id407039"></a>print command,
<a class="indexterm" name="id407046"></a>lpq command,
<a class="indexterm" name="id407053"></a>lprm command,
<a class="indexterm" name="id407060"></a>lppause command, and
<a class="indexterm" name="id407067"></a>lpresume command) are ignored, and they should normally have no
influence whatsoever on your printing.
</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407077"></a>Manual Configuration</h3></div></div></div><p>
If you want to do things manually, replace the <a class="indexterm" name="id407086"></a>printing = cups
by <a class="indexterm" name="id407093"></a>printing = bsd. Then your manually set commands may work
(I haven't tested this), and a <a class="indexterm" name="id407100"></a>print command = lp -d %P %s; rm %s
may do what you need.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id407111"></a>Printing from CUPS to Windows-Attached Printers</h2></div></div></div><p>
<a class="indexterm" name="id407119"></a>
<a class="indexterm" name="id407126"></a>
From time to time the question arises, how can you print <span class="emphasis"><em>to</em></span> a Windows-attached printer
<span class="emphasis"><em>from</em></span> Samba? Normally the local connection from Windows host to printer would be done by
USB or parallel cable, but this does not matter to Samba. From here only an SMB connection needs to be opened
to the Windows host. Of course, this printer must be shared first. As you have learned by now, CUPS uses
<span class="emphasis"><em>backends</em></span> to talk to printers and other servers. To talk to Windows shared printers, you
need to use the <code class="filename">smb</code> (surprise, surprise!) backend. Check if this is in the CUPS backend
directory. This usually resides in <code class="filename">/usr/lib/cups/backend/</code>. You need to find an
<code class="filename">smb</code> file there. It should be a symlink to <code class="filename">smbspool</code>, and the file
must exist and be executable:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>ls -l /usr/lib/cups/backend/</code></strong>
total 253
drwxr-xr-x 3 root root 720 Apr 30 19:04 .
drwxr-xr-x 6 root root 125 Dec 19 17:13 ..
-rwxr-xr-x 1 root root 10692 Feb 16 21:29 canon
-rwxr-xr-x 1 root root 10692 Feb 16 21:29 epson
lrwxrwxrwx 1 root root 3 Apr 17 22:50 http -> ipp
-rwxr-xr-x 1 root root 17316 Apr 17 22:50 ipp
-rwxr-xr-x 1 root root 15420 Apr 20 17:01 lpd
-rwxr-xr-x 1 root root 8656 Apr 20 17:01 parallel
-rwxr-xr-x 1 root root 2162 Mar 31 23:15 pdfdistiller
lrwxrwxrwx 1 root root 25 Apr 30 19:04 ptal -> /usr/sbin/ptal-cups
-rwxr-xr-x 1 root root 6284 Apr 20 17:01 scsi
lrwxrwxrwx 1 root root 17 Apr 2 03:11 smb -> /usr/bin/smbspool
-rwxr-xr-x 1 root root 7912 Apr 20 17:01 socket
-rwxr-xr-x 1 root root 9012 Apr 20 17:01 usb
<code class="prompt">root# </code><strong class="userinput"><code>ls -l `which smbspool`</code></strong>
-rwxr-xr-x 1 root root 563245 Dec 28 14:49 /usr/bin/smbspool
</pre><p>
If this symlink does not exist, create it:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>ln -s `which smbspool` /usr/lib/cups/backend/smb</code></strong>
</pre><p>
<a class="indexterm" name="id407234"></a>
<a class="indexterm" name="id407241"></a>
<code class="literal">smbspool</code> was written by Mike Sweet from the CUPS folks. It is included and ships with
Samba. It may also be used with print subsystems other than CUPS, to spool jobs to Windows printer shares. To
set up printer <em class="replaceable"><code>winprinter</code></em> on CUPS, you need to have a driver for it. Essentially
this means to convert the print data on the CUPS/Samba host to a format that the printer can digest (the
Windows host is unable to convert any files you may send). This also means you should be able to print to the
printer if it were hooked directly at your Samba/CUPS host. For troubleshooting purposes, this is what you
should do to determine if that part of the process chain is in order. Then proceed to fix the network
connection/authentication to the Windows host, and so on.
</p><p>
To install a printer with the <em class="parameter"><code>smb</code></em> backend on CUPS, use this command:
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>lpadmin -p winprinter -v smb://WINDOWSNETBIOSNAME/printersharename \
-P /path/to/PPD</code></strong>
</pre><p>
<a class="indexterm" name="id407294"></a>
<a class="indexterm" name="id407301"></a>
<a class="indexterm" name="id407307"></a>
The PPD must be able to direct CUPS to generate the print data for the target model. For PostScript printers,
just use the PPD that would be used with the Windows NT PostScript driver. But what can you do if the printer
is only accessible with a password? Or if the printer's host is part of another workgroup? This is provided
for: You can include the required parameters as part of the <code class="filename">smb://</code> device-URI like this:
</p><div class="itemizedlist"><ul type="disc"><li><p><code class="filename">smb://WORKGROUP/WINDOWSNETBIOSNAME/printersharename</code></p></li><li><p><code class="filename">smb://username:password@WORKGROUP/WINDOWSNETBIOSNAME/printersharename</code></p></li><li><p><code class="filename">smb://username:password@WINDOWSNETBIOSNAME/printersharename</code></p></li></ul></div><p>
Note that the device URI will be visible in the process list of the Samba server (e.g., when someone uses the
<code class="literal">ps -aux</code> command on Linux), even if the username and passwords are sanitized before they get
written into the log files. This is an inherently insecure option; however, it is the only one. Don't use it
if you want to protect your passwords. Better share the printer in a way that does not require a password!
Printing will only work if you have a working NetBIOS name resolution up and running. Note that this is a
feature of CUPS and you do not necessarily need to have smbd running.
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id407368"></a>More CUPS Filtering Chains</h2></div></div></div><p>
The diagrams in <a href="CUPS-printing.html#cups1" title="Figure 22.17. Filtering Chain 1.">Filtering Chain 1</a> and <a href="CUPS-printing.html#cups2" title="Figure 22.18. Filtering Chain with cupsomatic">Filtering Chain with
cupsomatic</a> show how CUPS handles print jobs.
</p><div class="figure"><a name="cups1"></a><p class="title"><b>Figure 22.17. Filtering Chain 1.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/cups1.png" alt="Filtering Chain 1."></div></div></div><br class="figure-break"><div class="figure"><a name="cups2"></a><p class="title"><b>Figure 22.18. Filtering Chain with cupsomatic</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/cups2.png" width="243" alt="Filtering Chain with cupsomatic"></div></div></div><br class="figure-break"></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id407477"></a>Common Errors</h2></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407482"></a>Windows 9x/Me Client Can't Install Driver</h3></div></div></div><p>For Windows 9x/Me, clients require the printer names to be eight
characters (or “<span class="quote">8 plus 3 chars suffix</span>”) max; otherwise, the driver files
will not get transferred when you want to download them from Samba.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="root-ask-loop"></a>“<span class="quote">cupsaddsmb</span>” Keeps Asking for Root Password in Never-ending Loop</h3></div></div></div><p>Have you set <a class="indexterm" name="id407512"></a>security = user? Have
you used <code class="literal">smbpasswd</code> to give root a Samba account?
You can do two things: open another terminal and execute
<code class="literal">smbpasswd -a root</code> to create the account and
continue entering the password into the first terminal. Or, break
out of the loop by pressing Enter twice (without trying to type a
password).</p><p>
If the error is “<span class="quote">Tree connect failed: NT_STATUS_BAD_NETWORK_NAME</span>”,
you may have forgotten to create the <code class="filename">/etc/samba/drivers</code> directory.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407549"></a>“<span class="quote">cupsaddsmb</span>” or “<span class="quote">rpcclient addriver</span>” Emit Error</h3></div></div></div><p>
If <code class="literal">cupsaddsmb</code>, or <code class="literal">rpcclient addriver</code> emit the error message
WERR_BAD_PASSWORD, refer to <a href="CUPS-printing.html#root-ask-loop" title="“cupsaddsmb” Keeps Asking for Root Password in Never-ending Loop">the previous common error</a>.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407585"></a>“<span class="quote">cupsaddsmb</span>” Errors</h3></div></div></div><p>
The use of “<span class="quote">cupsaddsmb</span>” gives “<span class="quote">No PPD file for printer...</span>”
message while PPD file is present. What might the problem be?
</p><p>
Have you enabled printer sharing on CUPS? This means, do you have a <code class="literal"><Location
/printers>....</Location></code> section in CUPS server's <code class="filename">cupsd.conf</code> that
does not deny access to the host you run “<span class="quote">cupsaddsmb</span>” from? It <span class="emphasis"><em>could</em></span> be an
issue if you use cupsaddsmb remotely, or if you use it with a <code class="option">-h</code> parameter:
<strong class="userinput"><code>cupsaddsmb -H sambaserver -h cupsserver -v printername</code></strong>.
</p><p>Is your <em class="parameter"><code>TempDir</code></em> directive in
<code class="filename">cupsd.conf</code> set to a valid value, and is it writable?
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407655"></a>Client Can't Connect to Samba Printer</h3></div></div></div><p>Use <code class="literal">smbstatus</code> to check which user
you are from Samba's point of view. Do you have the privileges to
write into the <em class="parameter"><code>[print$]</code></em>
share?</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407678"></a>New Account Reconnection from Windows 200x/XP Troubles</h3></div></div></div><p>
Once you are connected as the wrong user (for example, as <code class="constant">nobody</code>, which often occurs if
you have <a class="indexterm" name="id407691"></a>map to guest = bad user), Windows Explorer will not accept an
attempt to connect again as a different user. There will not be any bytes transferred on the wire to Samba,
but still you'll see a stupid error message that makes you think Samba has denied access. Use
<code class="literal">smbstatus</code> to check for active connections. Kill the PIDs. You still can't re-connect, and
you get the dreaded <code class="computeroutput">You can't connect with a second account from the same
machine</code> message as soon as you try. And you do not see a single byte arriving at Samba (see
logs; use “<span class="quote">ethereal</span>”) indicating a renewed connection attempt. Shut all Explorer Windows. This
makes Windows forget what it has cached in its memory as established connections. Then reconnect as the right
user. The best method is to use a DOS terminal window and <span class="emphasis"><em>first</em></span> do <strong class="userinput"><code>net use z:
\\GANDALF\print$ /user:root</code></strong>. Check with <code class="literal">smbstatus</code> that you are
connected under a different account. Now open the <span class="guilabel">Printers</span> folder (on the Samba server in
the <span class="guilabel">Network Neighborhood</span>), right-click on the printer in question, and select
<span class="guibutton">Connect....</span>.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407756"></a>Avoid Being Connected to the Samba Server as the Wrong User</h3></div></div></div><p>
<a class="indexterm" name="id407764"></a>
You see per <code class="literal">smbstatus</code> that you are connected as user nobody, but you want to be root or
printer admin. This is probably due to <a class="indexterm" name="id407778"></a>map to guest = bad user, which
silently connected you under the guest account when you gave (maybe by accident) an incorrect username. Remove
<a class="indexterm" name="id407786"></a>map to guest if you want to prevent this.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407795"></a>Upgrading to CUPS Drivers from Adobe Drivers</h3></div></div></div><p>
This information came from a mailing list posting regarding problems experienced when
upgrading from Adobe drivers to CUPS drivers on Microsoft Windows NT/200x/XP clients.
</p><p>First delete all old Adobe-using printers. Then delete all old Adobe drivers. (On Windows 200x/XP, right-click in
the background of <span class="guilabel">Printers</span> folder, select <span class="guimenuitem">Server Properties...</span>, select
tab <span class="guilabel">Drivers</span>, and delete here).</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407830"></a>Can't Use “<span class="quote">cupsaddsmb</span>” on Samba Server, Which Is a PDC</h3></div></div></div><p>Do you use the “<span class="quote">naked</span>” root user name? Try to do it
this way: <strong class="userinput"><code>cupsaddsmb -U <em class="replaceable"><code>DOMAINNAME</code></em>\\root -v
<em class="replaceable"><code>printername</code></em></code></strong>> (note the two backslashes: the first one is
required to “<span class="quote">escape</span>” the second one).</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407864"></a>Deleted Windows 200x Printer Driver Is Still Shown</h3></div></div></div><p>Deleting a printer on the client will not delete the
driver too (to verify, right-click on the white background of the
<span class="guilabel">Printers</span> folder, select <span class="guimenuitem">Server Properties</span> and click on the
<span class="guilabel">Drivers</span> tab). These same old drivers will be re-used when you try to
install a printer with the same name. If you want to update to a new
driver, delete the old ones first. Deletion is only possible if no
other printer uses the same driver.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407895"></a>Windows 200x/XP Local Security Policies</h3></div></div></div><a class="indexterm" name="id407901"></a><a class="indexterm" name="id407908"></a><p>Local security policies may not allow the installation of unsigned drivers “<span class="quote">local
security policies</span>” may not allow the installation of printer drivers at all.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407926"></a>Administrator Cannot Install Printers for All Local Users</h3></div></div></div><p>
<a class="indexterm" name="id407934"></a>
<a class="indexterm" name="id407941"></a>
Windows XP handles SMB printers on a “<span class="quote">per-user</span>” basis.
This means every user needs to install the printer himself or herself. To have a printer available for
everybody, you might want to use the built-in IPP client capabilities of Win XP. Add a printer with the print
path of <em class="parameter"><code>http://cupsserver:631/printers/printername</code></em>. We're still looking into this one.
Maybe a logon script could automatically install printers for all users.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407963"></a>Print Change, Notify Functions on NT Clients</h3></div></div></div><p>For print change, notify functions on NT++ clients. These need to run the <code class="literal">Server</code>
service first (renamed to <code class="literal">File & Print Sharing for MS Networks</code> in XP).</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id407987"></a>Win XP-SP1</h3></div></div></div><p>Win XP-SP1 introduced a Point and Print Restriction Policy (this restriction does not apply to
“<span class="quote">Administrator</span>” or “<span class="quote">Power User</span>” groups of users). In Group Policy Object Editor, go
to <span class="guimenu">User Configuration -> Administrative Templates -> Control Panel -> Printers</span>. The policy
is automatically set to <code class="constant">Enabled</code> and the <code class="constant">Users can only Point and Print to
machines in their Forest</code> . You probably need to change it to <code class="constant">Disabled</code> or
<code class="constant">Users can only Point and Print to these servers</code> to make driver downloads from Samba
possible.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id408028"></a>Print Options for All Users Can't Be Set on Windows 200x/XP</h3></div></div></div><p>How are you doing it? I bet the wrong way (it is not easy to find out, though). There are three
different ways to bring you to a dialog that <span class="emphasis"><em>seems</em></span> to set everything. All three dialogs
<span class="emphasis"><em>look</em></span> the same, yet only one of them does what you intend. You need to be Administrator or
Print Administrator to do this for all users. Here is how I do in on XP:
</p><div class="orderedlist"><ol type="A"><li><p>The first wrong way:
</p><div class="orderedlist"><ol type="I"><li><p>Open the <span class="guilabel">Printers</span>
folder.</p></li><li><p>Right-click on the printer
(<span class="guilabel">remoteprinter on cupshost</span>) and
select in context menu <span class="guimenuitem">Printing
Preferences...</span></p></li><li><p>Look at this dialog closely and remember what it looks like.</p></li></ol></div><p>
</p></li><li><p>The second wrong way:
</p><div class="orderedlist"><ol type="I"><li><p>Open the <span class="guilabel">Printers</span> folder.</p></li><li><p>Right-click on the printer (<span class="guilabel">remoteprinter on
cupshost</span>) and select the context menu
<span class="guimenuitem">Properties</span>.</p></li><li><p>Click on the <span class="guilabel">General</span> tab.</p></li><li><p>Click on the button <span class="guibutton">Printing
Preferences...</span></p></li><li><p>A new dialog opens. Keep this dialog open and go back
to the parent dialog.</p></li></ol></div><p>
</p></li><li><p>The third and correct way:
</p><div class="orderedlist"><ol type="I"><li><p>Open the <span class="guilabel">Printers</span> folder.</p></li><li><p>Right-click on the printer (<span class="guilabel">remoteprinter on
cupshost</span>) and select the context menu
<span class="guimenuitem">Properties</span>.</p></li><li><p>Click on the <span class="guilabel">Advanced</span>
tab. (If everything is “<span class="quote">grayed out,</span>” then you are not logged
in as a user with enough privileges).</p></li><li><p>Click on the <span class="guibutton">Printing
Defaults...</span> button.</p></li><li><p>On any of the two new tabs, click on the
<span class="guibutton">Advanced...</span> button.</p></li><li><p>A new dialog opens. Compare this one to the other
identical-looking one from step “<span class="quote">B.5</span>” or A.3".</p></li></ol></div><p>
</p></li></ol></div><p>
Do you see any difference? I don't either. However, only the last one, which you arrived at with steps
“<span class="quote">C.1. to C.6.</span>”, will save any settings permanently and be the defaults for new users. If you want
all clients to get the same defaults, you need to conduct these steps <span class="emphasis"><em>as Administrator</em></span>
(<a class="indexterm" name="id408262"></a>printer admin in <code class="filename">smb.conf</code>) <span class="emphasis"><em>before</em></span> a client downloads the
driver (the clients can later set their own <span class="emphasis"><em>per-user defaults</em></span> by following the procedures
<span class="emphasis"><em>A</em></span> or <span class="emphasis"><em>B</em></span>).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id408292"></a>Most Common Blunders in Driver Settings on Windows Clients</h3></div></div></div><p>
Don't use <em class="parameter"><code>Optimize for Speed</code></em>, but use <em class="parameter"><code>Optimize for Portability</code></em>
instead (Adobe PS Driver). Don't use <em class="parameter"><code>Page Independence: No</code></em>. Always settle with
<em class="parameter"><code>Page Independence: Yes</code></em> (Microsoft PS Driver and CUPS PS Driver for Windows NT/200x/XP).
If there are problems with fonts, use <em class="parameter"><code>Download as Softfont into printer</code></em> (Adobe PS
Driver). For <span class="guilabel">TrueType Download Options</span> choose <code class="constant">Outline</code>. Use
PostScript Level 2 if you are having trouble with a non-PS printer and if there is a choice.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id408345"></a><code class="literal">cupsaddsmb</code> Does Not Work with Newly Installed Printer</h3></div></div></div><p>
Symptom: The last command of <code class="literal">cupsaddsmb</code> does not complete successfully. If the <code class="literal">cmd
= setdriver printername printername</code> result was NT_STATUS_UNSUCCESSFUL, then possibly the printer was
not yet recognized by Samba. Did it show up in Network Neighborhood? Did it show up in <code class="literal">rpcclient
hostname -c `enumprinters'</code>? Restart smbd (or send a <code class="literal">kill -HUP</code> to all processes
listed by <code class="literal">smbstatus</code>, and try again.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id408391"></a>Permissions on <code class="filename">/var/spool/samba/</code> Get Reset After Each Reboot</h3></div></div></div><p>
Have you ever by accident set the CUPS spool directory to the same location (<em class="parameter"><code>RequestRoot
/var/spool/samba/</code></em> in <code class="filename">cupsd.conf</code> or the other way round:
<code class="filename">/var/spool/cups/</code> is set as <a class="indexterm" name="id408424"></a>path> in the <em class="parameter"><code>[printers]</code></em> section)? These <em class="parameter"><code>must</code></em> be different. Set <em class="parameter"><code>RequestRoot
/var/spool/cups/</code></em> in <code class="filename">cupsd.conf</code> and <a class="indexterm" name="id408455"></a>path =
/var/spool/samba in the <em class="parameter"><code>[printers]</code></em> section of <code class="filename">smb.conf</code>. Otherwise,
cupsd will sanitize permissions to its spool directory with each restart and printing will not work reliably.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id408477"></a>Print Queue Called “<span class="quote">lp</span>” Mishandles Print Jobs</h3></div></div></div><p>
In this case a print queue called “<span class="quote">lp</span>” intermittently swallows jobs and
spits out completely different ones from what was sent.
</p><p>
<a class="indexterm" name="id408496"></a>
<a class="indexterm" name="id408503"></a>
<a class="indexterm" name="id408510"></a>
It is a bad idea to name any printer “<span class="quote">lp</span>”. This is the traditional UNIX name for the default
printer. CUPS may be set up to do an automatic creation of Implicit Classes. This means, to group all printers
with the same name to a pool of devices and load-balance the jobs across them in a round-robin fashion.
Chances are high that someone else has a printer named “<span class="quote">lp</span>” too. You may receive that person's
jobs and send your own to his or her device unwittingly. To have tight control over the printer names, set
<em class="parameter"><code>BrowseShortNames No</code></em>. It will present any printer as
<em class="replaceable"><code>printername@cupshost</code></em>, which gives you better control over what may happen in a
large networked environment.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id408540"></a>Location of Adobe PostScript Driver Files for “<span class="quote">cupsaddsmb</span>”</h3></div></div></div><p>
Use <code class="literal">smbclient</code> to connect to any Windows box with a shared PostScript printer:
<code class="literal">smbclient //windowsbox/print\$ -U guest</code>. You can navigate to the
<code class="filename">W32X86/2</code> subdir to <code class="literal">mget ADOBE*</code> and other files or to
<code class="filename">WIN40/0</code> to do the same. Another option is to download the <code class="filename">*.exe</code>
packaged files from the Adobe Web site.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id408591"></a>Overview of the CUPS Printing Processes</h2></div></div></div><p>
A complete overview of the CUPS printing processes can be found in <a href="CUPS-printing.html#a_small" title="Figure 22.19. CUPS Printing Overview.">the CUPS
Printing Overview diagram</a>.
</p><div class="figure"><a name="a_small"></a><p class="title"><b>Figure 22.19. CUPS Printing Overview.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/a_small.png" width="243" alt="CUPS Printing Overview."></div></div></div><br class="figure-break"></div><div class="footnotes"><br><hr width="100" align="left"><div class="footnote"><p><sup>[<a name="ftn.id398861" href="#id398861">6</a>] </sup>See also <a href="http://www.cups.org/cups-help.html" target="_top">http://www.cups.org/cups-help.html</a></p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="classicalprinting.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="optional.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="VFS.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 21. Classical Printing Support </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 23. Stackable VFS modules</td></tr></table></div></body></html>