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diff --git a/docs/docbook/projdoc/CUPS-printing.xml b/docs/docbook/projdoc/CUPS-printing.xml new file mode 100644 index 0000000000..adb93dcc9d --- /dev/null +++ b/docs/docbook/projdoc/CUPS-printing.xml @@ -0,0 +1,5406 @@ +<chapter id="CUPS-printing"> + +<chapterinfo> + + <author> + <firstname>Kurt</firstname><surname>Pfeifle</surname> + <affiliation> + <orgname>Danka Deutschland GmbH </orgname> + <address><email>kpfeifle@danka.de</email></address> + </affiliation> + </author> + <author> + <firstname>Ciprian</firstname><surname>Vizitiu</surname> + <affiliation> + <address><email>CVizitiu@gbif.org</email></address> + </affiliation> + <contrib>drawings</contrib> + </author> + + <author>&person.jelmer;<contrib>drawings</contrib></author> + + <pubdate> (3 June 2003) </pubdate> +</chapterinfo> + +<title>CUPS Printing Support</title> + +<sect1> + + <title>Introduction</title> + + <sect2> + <title>Features and Benefits</title> + + <para> + The Common UNIX Print System (<ulink url="http://www.cups.org/">CUPS</ulink>) + 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 <quote>black box</quote> + that they do not want to look into as long as it works. But once + there is a little problem, they are in trouble to find out where to + start debugging it. Refer to the chapter <quote>Classical Printing</quote> that + contains a lot of information that is relevant for CUPS. + </para> + + <para> + CUPS sports quite a few unique and powerful features. While their + basic functions may be grasped quite easily, they are also + new. Because they are different from other, more traditional printing + systems, it is best not to try and 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. + </para> + + </sect2> + + <sect2> + <title>Overview</title> + + <para> + 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 a + 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 <ulink url="http://printing.kde.org/">KDEPrint</ulink>). + </para> + + <para> + CUPS allows creation of <quote>raw</quote> printers (i.e., no print file + format translation) as well as <quote>smart</quote> printers (i.e., CUPS does + file format conversion as required for the printer). In many ways + this gives CUPS similar capabilities 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 move on to + explore how one may configure CUPS for interfacing with MS Windows + print clients via Samba. + </para> + </sect2> +</sect1> + +<sect1> + <title>Basic CUPS Support Configuration</title> + + <para> + Printing with CUPS in the most basic &smb.conf; setup in Samba-3.0 (as was true for 2.2.x) only needs two + settings: <smbconfoption><name>printing</name><value>cups</value></smbconfoption> and + <smbconfoption><name>printcap</name><value>cups</value></smbconfoption>. CUPS does not need a printcap file. + However, the <filename>cupsd.conf</filename> 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: <parameter>Printcap /etc/printcap</parameter> and <parameter>PrintcapFormat BSD</parameter>). + 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 + <command>man cupsd.conf</command> and other CUPS-related documentation, like the wealth of documents on your CUPS server + itself: <ulink noescape="1" url="http://localhost:631/documentation.html">http://localhost:631/documentation.html</ulink>. + </para> + + <sect2> + <title>Linking smbd with libcups.so</title> + + <para> + Samba has a special relationship to CUPS. Samba can be compiled with CUPS library support. + Most recent installations have this support enabled. Per default, CUPS linking is compiled + into smbd and other Samba binaries. Of course, you can use CUPS even + if Samba is not linked against <filename>libcups.so</filename> &smbmdash; but + there are some differences in required or supported configuration. + </para> + + <para> + When Samba is compiled against <filename>libcups</filename>, <smbconfoption><name>printcap</name><value>cups</value></smbconfoption> + 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 <command>-oraw</command> option for printing. On a Linux + system, you can use the <command>ldd</command> utility to find out details (ldd may not be present on + other OS platforms, or its function may be embodied by a different command): + </para> + +<para><screen> +&rootprompt;<userinput>ldd `which smbd`</userinput> +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) +[....] +</screen></para> + + <para> + The line <computeroutput>libcups.so.2 => /usr/lib/libcups.so.2 (0x40123000)</computeroutput> shows + there is CUPS support compiled into this version of Samba. If this is the case, and printing = cups + is set, then <emphasis>any otherwise manually set print command in &smb.conf; is ignored</emphasis>. + This is an important point to remember! + </para> + + <tip><para> Should it be necessary, for any reason, to set your own print commands, you can do this by setting + <smbconfoption><name>printing</name><value>sysv</value></smbconfoption>. However, you will loose all the benefits + of tight CUPS/Samba integration. When you do this you must manually configure the printing system commands + (most important: + <smbconfoption><name>print command</name></smbconfoption>; other commands are + <smbconfoption><name>lppause command</name></smbconfoption>, + <smbconfoption><name>lpresume command</name></smbconfoption>, + <smbconfoption><name>lpq command</name></smbconfoption>, + <smbconfoption><name>lprm command</name></smbconfoption>, + <smbconfoption><name>queuepause command</name></smbconfoption> and + <smbconfoption><name>queue resume command</name></smbconfoption>).</para></tip> + </sect2> + + <sect2> + <title>Simple &smb.conf; Settings for CUPS</title> + + <para> + To summarize, <link linkend="cups-exam-simple">the example below</link> shows simplest printing-related setup for &smb.conf; to enable basic CUPS support: + </para> + + <para><smbconfexample id="cups-exam-simple"> + <title>Simplest printing-related smb.conf</title> + <smbconfsection>[global]</smbconfsection> + <smbconfoption><name>load printers</name><value>yes</value></smbconfoption> + <smbconfoption><name>printing</name><value>cups</value></smbconfoption> + <smbconfoption><name>printcap name</name><value>cups</value></smbconfoption> + + <smbconfsection>[printers]</smbconfsection> + <smbconfoption><name>comment</name><value>All Printers</value></smbconfoption> + <smbconfoption><name>path</name><value>/var/spool/samba</value></smbconfoption> + <smbconfoption><name>browseable</name><value>no</value></smbconfoption> + <smbconfoption><name>public</name><value>yes</value></smbconfoption> + <smbconfoption><name>guest ok</name><value>yes</value></smbconfoption> + <smbconfoption><name>writable</name><value>no</value></smbconfoption> + <smbconfoption><name>printable</name><value>yes</value></smbconfoption> + <smbconfoption><name>printer admin</name><value>root, @ntadmins</value></smbconfoption> + + </smbconfexample></para> + + <para> + 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 hardly submit graphic, text or PDF + formatted files directly to the spooler. They nearly exclusively print + from GUI applications with a <quote>printer driver</quote> hooked in 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 <quote>binary,</quote> + sensible only for the target printer. Read on to learn which problem + this may cause and how to avoid it. + </para> + </sect2> + + <sect2> + <title>More Complex CUPS &smb.conf; Settings</title> + + <para> + <link linkend="overridesettings">The example below</link> is a slightly more complex printing-related setup + for &smb.conf;. It enables general CUPS printing + support for all printers, but defines one printer share, which is set + up differently. + </para> + + <para><smbconfexample id="overridesettings"> + <title>Overriding global CUPS settings for one printer</title> + <smbconfsection>[global]</smbconfsection> + <smbconfoption><name>printing</name><value>cups</value></smbconfoption> + <smbconfoption><name>printcap name</name><value>cups</value></smbconfoption> + <smbconfoption><name>load printers</name><value>yes</value></smbconfoption> + + <smbconfsection>[printers]</smbconfsection> + <smbconfoption><name>comment</name><value>All Printers</value></smbconfoption> + <smbconfoption><name>path</name><value>/var/spool/samba</value></smbconfoption> + <smbconfoption><name>public</name><value>yes</value></smbconfoption> + <smbconfoption><name>guest ok</name><value>yes</value></smbconfoption> + <smbconfoption><name>writable</name><value>no</value></smbconfoption> + <smbconfoption><name>printable</name><value>yes</value></smbconfoption> + <smbconfoption><name>printer admin</name><value>root, @ntadmins</value></smbconfoption> + + <smbconfsection>[special_printer]</smbconfsection> + <smbconfoption><name>comment</name><value>A special printer with his own settings</value></smbconfoption> + <smbconfoption><name>path</name><value>/var/spool/samba-special</value></smbconfoption> + <smbconfoption><name>printing</name><value>sysv</value></smbconfoption> + <smbconfoption><name>printcap</name><value>lpstat</value></smbconfoption> + <smbconfoption><name>print command</name><value>echo "NEW: `date`: printfile %f" >> /tmp/smbprn.log ; \</value></smbconfoption> + <member><parameter>echo " `date`: p-%p s-%s f-%f" >> /tmp/smbprn.log ; \</parameter></member> + <member><parameter>echo " `date`: j-%j J-%J z-%z c-%c" >> /tmp/smbprn.log : rm %f</parameter></member> + <smbconfoption><name>public</name><value>no</value></smbconfoption> + <smbconfoption><name>guest ok</name><value>no</value></smbconfoption> + <smbconfoption><name>writeable</name><value>no</value></smbconfoption> + <smbconfoption><name>printable</name><value>yes</value></smbconfoption> + <smbconfoption><name>printer admin</name><value>kurt</value></smbconfoption> + <smbconfoption><name>hosts deny</name><value>0.0.0.0</value></smbconfoption> + <smbconfoption><name>hosts allow</name><value>turbo_xp, 10.160.50.23, 10.160.51.60</value></smbconfoption> + </smbconfexample></para> + + <para> + This special share is only there for testing purposes. It does not write the print job to a file. It just logs the job parameters + known to Samba into the <filename>/tmp/smbprn.log</filename> file and deletes the jobfile. Moreover, the + <smbconfoption><name>printer admin</name></smbconfoption> of this share is <quote>kurt</quote> (not the <quote>@ntadmins</quote> 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 only + allows access from only three hosts. To prevent CUPS kicking in and taking over the print jobs for that share, we need to set + <smbconfoption><name>printing</name><value>sysv</value></smbconfoption> and + <smbconfoption><name>printcap</name><value>lpstat</value></smbconfoption>. + </para> + </sect2> +</sect1> + +<sect1> + <title>Advanced Configuration</title> + + <para> + Before we delve into all the configuration options, let us clarify a few + points. <emphasis>Network printing needs to be organized and setup + correctly</emphasis>. This frequently doesn't happen. Legacy systems + or small business LAN environments often lack design and good housekeeping. + </para> + + + <sect2> + <title>Central Spooling vs. <quote>Peer-to-Peer</quote> Printing</title> + + + <para> +<indexterm><primary>spooling</primary><secondary>central</secondary></indexterm> +<indexterm><primary>spooling</primary><secondary>peer-to-peer</secondary></indexterm> + 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 usage of a print server: it routes all jobs through one + central system, which responds immediately, takes jobs from multiple + concurrent clients at the same time, and in turn transfers them to the + printer(s) in the correct order. + </para> + </sect2> + + <sect2> + <title>Raw Print Serving &smbmdash; Vendor Drivers on Windows Clients</title> + + + <para> + <indexterm><primary>spooling-only</primary></indexterm> + <indexterm><primary>"raw" printing</primary></indexterm> + 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 <quote>raw</quote> 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 its ready to be sent to the printing + device. Here is a native (vendor-supplied) Windows printer + driver for the target device needed to be installed on each and every + client. + </para> + + <para> + 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. + </para> + </sect2> + + <sect2> + <title>Installation of Windows Client Drivers</title> + + <para> + The printer drivers on the Windows clients may be installed + in two functionally different ways: + </para> + + <itemizedlist> + <listitem><para>Manually install the drivers locally on each client, + one by one; this yields the old <emphasis>LanMan</emphasis> style + printing and uses a <filename>\\sambaserver\printershare</filename> + type of connection.</para></listitem> + + + <listitem><para> + <indexterm><primary>point 'n' print</primary></indexterm> + Deposit and prepare the drivers (for later download) on + the print server (Samba); this enables the clients to use + <quote>Point'n'Print</quote> to get drivers semi-automatically installed the + first time they access the printer; with this method NT/200x/XP + clients use the <emphasis>SPOOLSS/MS-RPC</emphasis> + type printing calls.</para></listitem> + </itemizedlist> + + <para> + The second method is recommended for use over the first. + </para> + </sect2> + + <sect2 id="cups-raw"> + <title>Explicitly Enable <quote>raw</quote> Printing for <emphasis>application/octet-stream</emphasis></title> + + + <para> + <indexterm><primary>application/octet-stream</primary></indexterm> + <indexterm><primary>raw printing</primary></indexterm> + <indexterm><primary>MIME</primary><secondary>raw</secondary></indexterm> + 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 <quote>raw</quote> printing of deliberate (binary) file + formats. The CUPS files that need to be correctly set for RAW mode + printers to work are: + </para> + + <itemizedlist> + <listitem><para><filename>/etc/cups/mime.types</filename></para></listitem> + <listitem><para><filename>/etc/cups/mime.convs</filename></para></listitem> + </itemizedlist> + + <para> + Both contain entries (at the end of the respective files) which must + be uncommented to allow RAW mode operation. + In <filename>/etc/cups/mime.types</filename>, make sure this line is + present: + + <filterline> + application/octet-stream + </filterline> + + <indexterm><primary>/etc/cups/mime.convs</primary></indexterm> + <indexterm><primary>/etc/cups/mime.types</primary></indexterm> + + In <filename>/etc/cups/mime.convs</filename>, + have this line: + + <indexterm><primary>application/vnd.cups-raw</primary></indexterm> + + <filterline> + application/octet-stream application/vnd.cups-raw 0 - + </filterline> + + If these two files are not set up correctly for raw Windows client + printing, you may encounter the dreaded <computeroutput>Unable to + convert file 0</computeroutput> in your CUPS error_log file. + </para> + + <note><para>Editing the <filename>mime.convs</filename> and the + <filename>mime.types</filename> file does not + <emphasis>enforce</emphasis> <quote>raw</quote> printing, it only + <emphasis>allows</emphasis> it. + </para></note> + + <formalpara><title>Background</title> + + + <para> + <indexterm><primary>application/octet-stream</primary></indexterm> + CUPS being 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 + <quote>Denial of Service</quote> attack on your printer(s), causing at least + the loss of a lot of paper and ink. <quote>Unknown</quote> data are tagged by CUPS + as <parameter>MIME type: application/octet-stream</parameter> and not + allowed to go to the printer. By default, you can only send other + (known) MIME types <quote>raw</quote>. Sending data <quote>raw</quote> means that CUPS does not + try to convert them and passes them to the printer untouched (see the next + chapter for even more background explanations). + </para> + </formalpara> + + <para> + This is all you need to know to get the CUPS/Samba combo printing + <quote>raw</quote> 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. + </para> + </sect2> + + <sect2> + <title>Driver Upload Methods</title> + + <para> + This section describes three familiar methods, plus one new one, by which + printer drivers may be uploaded. + </para> + + <para> + <indexterm><primary>point 'n' print</primary></indexterm> + If you want to use the MS-RPC type printing, you must upload the + drivers onto the Samba server first (<smbconfsection>[print$]</smbconfsection> + share). For a discussion on how to deposit printer drivers on the + Samba host (so the Windows clients can download and use them via + <quote>Point'n'Print</quote>), please refer to the previous chapter of this + HOWTO Collection. There you will find a description or reference to + three methods of preparing the client drivers on the Samba server: + </para> + <itemizedlist> + <listitem><para> + <indexterm><primary>add printer wizard</primary></indexterm> + The GUI, <quote>Add Printer Wizard</quote> + <emphasis>upload-from-a-Windows-client</emphasis> + method.</para></listitem> + + <listitem><para>The command line, <quote>smbclient/rpcclient</quote> + upload-from-a-UNIX-workstation method.</para></listitem> + + + <listitem><para> + <indexterm><primary>imprints</primary></indexterm> + The Imprints Toolset + method.</para></listitem> + </itemizedlist> + + <para> + These three methods apply to CUPS all the same. A new and more + convenient way to load the Windows drivers into Samba is provided + if you use CUPS: + </para> + + + <itemizedlist> + <listitem><para> + <indexterm><primary>cupsaddsmb</primary></indexterm> + the <parameter>cupsaddsmb</parameter> + utility.</para></listitem> + </itemizedlist> + + <para> + <command>cupsaddsmb</command> is discussed in much detail further below. But we first + explore the CUPS filtering system and compare the Windows and UNIX printing architectures. + </para> + </sect2> +</sect1> + +<sect1> + <title>Advanced Intelligent Printing with PostScript Driver Download</title> + + + <para> + <indexterm><primary>PostScript</primary><seealso>Ghostscript</seealso></indexterm> + We now know + how to set up a <quote>dump</quote> printserver, that is, a server which is spooling + printjobs <quote>raw</quote>, leaving the print data untouched. + </para> + + <para> + Possibly you need to setup CUPS in a smarter way. The reasons could + be manifold: + </para> + + <itemizedlist> + <listitem><para>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?</para></listitem> + + <listitem><para>Maybe you are asked to setup a print quota system: + Users should not be able to print more jobs, once they have surpassed + a given limit per period.</para></listitem> + + <listitem><para>Maybe your previous network printing setup is a mess + and must be re-organized from a clean beginning.</para></listitem> + + <listitem><para>Maybe you have experiencing too many <quote>blue screens</quote> + originating from poorly debugged printer drivers running in NT <quote>kernel mode</quote>?</para></listitem> + </itemizedlist> + + <para> + These goals cannot be achieved by a raw print server. To build a + server meeting these requirements, you'll first need to learn about + how CUPS works and how you can enable its features. + </para> + + <para> + What follows is the comparison of some fundamental concepts for + Windows and UNIX printing; then follows a description of the + CUPS filtering system, how it works and how you can tweak it. + </para> + + <sect2 id="gdipost"> + <title>GDI on Windows -- PostScript on UNIX</title> + + + <para> + <indexterm><primary>GDI</primary></indexterm> + <indexterm><primary>PostScript</primary></indexterm> + 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 for this. + </para> + + + <para> + <indexterm><primary>PCL</primary></indexterm> + <indexterm><primary>PDL</primary></indexterm> + You can't expect most file formats to just throw them toward + printers and they get printed. There needs to be a file format + conversion in between. 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 HP) have developed + into semi-official <quote>standards</quote> by being the most widely used PDLs + Page Description Languages (PDLs), there are still + many manufacturers who <quote>roll their own</quote> (their reasons may be + unacceptable license fees for using printer-embedded PostScript + interpreters, and so on). + </para> + </sect2> + + <sect2> + <title>Windows Drivers, GDI and EMF</title> + + + <para> + <indexterm><primary>GDI</primary></indexterm> + <indexterm><primary>EMF</primary></indexterm> + <indexterm><primary>WYSIWYG</primary></indexterm> + 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 + <emphasis>on screen</emphasis> as well as <emphasis>on + paper</emphasis> (print). Therefore, printer driver developers can + standardize on a well-defined GDI output for their own driver + input. Achieving WYSIWYG (<quote>What You See Is What You Get</quote>) 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. + </para> + + <note><para> + <indexterm><primary>PDF</primary></indexterm> + To the GDI foundation in MS Windows, Apple has chosen to + put paper and screen output on a common foundation for their + (BSD-UNIX-based, did you know?) Mac OS X and Darwin Operating + <indexterm><primary>X Window System</primary></indexterm> + <indexterm><primary>PostScript</primary></indexterm> + <indexterm><primary>PCL</primary></indexterm> + <indexterm><primary>Xprint</primary></indexterm> + Systems. Their <emphasis>Core Graphic Engine</emphasis> uses a + <emphasis>PDF</emphasis> derivative for all display work. + </para></note> + + <para> + + <image id="small1"><imagedescription>Windows printing to a local printer.</imagedescription><imagefile>1small</imagefile></image> + </para> + </sect2> + + <sect2> + <title>UNIX Printfile Conversion and GUI Basics</title> + + + <para> + <indexterm><primary>X Window System</primary></indexterm> + <indexterm><primary>PostScript</primary></indexterm> + <indexterm><primary>PCL</primary></indexterm> + <indexterm><primary>Xprint</primary></indexterm> + 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 <quote>paper output</quote> + also, as some had demanded at the time, and restricted itself to + <quote>on-screen only.</quote> (For some years now, the <quote>Xprint</quote> 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 <quote>font</quote> directories on your + system; there are separate ones for fonts used for X display and fonts + to be used on paper. + </para> + + <formalpara> + <title>Background</title> + + + <para> + <indexterm><primary>PostScript</primary></indexterm> + The PostScript programming language is an <quote>invention</quote> by Adobe Inc., + but its specifications have been published to the full. 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 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 + <quote>raster images</quote> or <quote>pixels</quote> (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 which 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. + </para> + </formalpara> + </sect2> + + <sect2 id="post-and-ghost"> + <title>PostScript and Ghostscript</title> + + + <para> + <indexterm><primary>PostScript</primary></indexterm> + <indexterm><primary>GhostScript</primary><seealso>PostScript</seealso></indexterm> + <indexterm><primary>PostScript</primary><secondary>RIP</secondary></indexterm> + 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 these devices have a built-in PostScript + language <quote>interpreter,</quote> 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. Their RIP is doing 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 to PostScript printing a file from a Windows origin. + </para> + + <note><para> + <indexterm><primary>PPD</primary></indexterm> + Traditional UNIX programs and printing systems &smbmdash; while + using PostScript &smbmdash; are largely not PPD-aware. PPDs are <quote>PostScript + Printer Description</quote> 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. + </para> + </note> + + <para> + <image id="small2"><imagedescription>Printing to a PostScript printer.</imagedescription> + <imagefile>2small</imagefile></image> + </para> + + + <para> + <indexterm><primary>PDL</primary></indexterm> + However, there are other types of printers out there. These do not know + how to print PostScript. They use their own Page Description + Language (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 printfiles to a format suitable for your printer + on the host before you can send it away. + </para> + </sect2> + + <sect2> + <title>Ghostscript &smbmdash; the Software RIP for Non-PostScript Printers</title> + + + <para> + <indexterm><primary>GhostScript</primary></indexterm> + 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 + <emphasis>lot</emphasis> 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. + </para> + + <para> + <image id="small3"><imagedescription>Ghostscript as a RIP for non-postscript printers.</imagedescription> + <imagefile>3small</imagefile> + </image> + </para> + + <tip><para> + Use the <quote>gs -h</quote> command to check for all built-in <quote>devices</quote> + of your Ghostscript version. If you specify a parameter of + <parameter>-sDEVICE=png256</parameter> on your Ghostscript command + line, you are asking Ghostscript to convert the input into a PNG + file. Naming a <quote>device</quote> 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 + <quote>AFPL</quote> 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. + <indexterm><primary>Ghostscript</primary><secondary>ESP</secondary><see>ESP GhostScript</see></indexterm> + 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, RedHat, and Debian. It includes + the <quote>cups</quote> device (essential to print to non-PS printers from CUPS). + </para></tip> + </sect2> + + <sect2> + <title>PostScript Printer Description (PPD) Specification</title> + + + <para> + <indexterm><primary>PPD</primary></indexterm> + While PostScript in essence is a Page Description + Language (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. + </para> + + <para> + 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. + </para> + + <para> + 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. + </para> + + <warning><para> + <indexterm><primary>PDF</primary></indexterm> + 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). + </para></warning> + </sect2> + + <sect2> + <title>Using Windows-Formatted Vendor PPDs</title> + + <para> + CUPS can handle all spec-compliant PPDs as supplied by the + manufacturers for their PostScript models. Even if a + vendor might not have mentioned our favorite + OS in his manuals and brochures, you can safely trust this: + <emphasis>If you get the Windows NT version of the PPD, you + can use it unchanged in CUPS</emphasis> and thus access the full + power of your printer just like a Windows NT user could! + </para> + + <tip><para> + To check the spec compliance of any PPD online, go to <ulink + noescape="1" url="http://www.cups.org/testppd.php">http://www.cups.org/testppd.php</ulink> + and upload your PPD. You will see the results displayed + immediately. CUPS in all versions after 1.1.19 has a much more strict + internal PPD parsing and checking code enabled; in case of printing + trouble, this online resource should be one of your first pitstops. + </para></tip> + + <warning><para> + <indexterm><primary>foomatic</primary></indexterm> + <indexterm><primary>cupsomatic</primary></indexterm> + For real PostScript printers, <emphasis>do not</emphasis> use the + <emphasis>Foomatic</emphasis> or <emphasis>cupsomatic</emphasis> + PPDs from Linuxprinting.org. With these devices, the original + vendor-provided PPDs are always the first choice! + </para></warning> + + <tip><para> + 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 + <command>smbclient //NT4-box/print\$ -U username</command> to + access the Windows directory where all printer driver files are + stored. First look in the <filename>W32X86/2</filename> subdir for + the PPD you are seeking. + </para></tip> + </sect2> + + <sect2> + <title>CUPS Also Uses PPDs for Non-PostScript Printers</title> + + <para> + 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. + </para> + </sect2> +</sect1> + +<sect1> +<title>The CUPS Filtering Architecture</title> + +<para> +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 +printfile is subjected to an initial +auto-typing. The auto-typing 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 setup a working filtering chain for any +given input data format. +</para> + +<para> +If CUPS rasterizes a PostScript file natively to +a bitmap, this is done in two stages: +</para> + +<itemizedlist> + <listitem><para>The first stage uses a Ghostscript device named <quote>cups</quote> +(this is since version 1.1.15) and produces a generic raster format +called <quote>CUPS raster</quote>. +</para></listitem> + +<listitem><para>The second stage uses a <quote>raster driver</quote> that converts + the generic CUPS raster to a device-specific raster.</para></listitem> +</itemizedlist> + +<para> +Make sure your Ghostscript version has the <quote>cups</quote> device compiled in +(check with <command>gs -h | grep cups</command>). Otherwise you +may encounter the dreaded <computeroutput>Unable to convert file +0</computeroutput> in your CUPS error_log file. To have <quote>cups</quote> as a +device in your Ghostscript, you either need to patch GNU +Ghostscript and re-compile, or use <indexterm><primary>ESP</primary><secondary>Ghostscript</secondary></indexterm><ulink +url="http://www.cups.org/ghostscript.php">ESP Ghostscript</ulink>. The +superior alternative is ESP Ghostscript. It supports not just CUPS, +but 300 other devices too (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. +</para> + +<para> +<indexterm><primary>cupsomatic</primary></indexterm> +<indexterm><primary>foomatic</primary></indexterm> +CUPS printers may be setup to use external +rendering paths. One of the most common is provided by the +Foomatic/cupsomatic concept from <ulink +url="http://www.linuxprinting.org/">Linuxprinting.org.</ulink> This +uses the classical Ghostscript approach, doing everything in one +step. It does not use the <quote>cups</quote> device, but one of the many +others. However, even for Foomatic/cupsomatic usage, best results and +<indexterm><primary>ESP</primary><secondary>Ghostscript</secondary></indexterm> +broadest printer model support is provided by ESP Ghostscript (more +about cupsomatic/Foomatic, particularly the new version called now +<emphasis>foomatic-rip</emphasis>, follows below). +</para> + +<sect2> +<title>MIME Types and CUPS Filters</title> + + +<para> +<indexterm><primary>MIME</primary><secondary>filters</secondary></indexterm> + <indexterm><primary>MIME</primary></indexterm> +CUPS reads the file <filename>/etc/cups/mime.types</filename> +(and all other files carrying a <filename>*.types</filename> suffix +in the same directory) upon startup. These files contain the MIME +type recognition rules that are applied when CUPS runs its +auto-typing routines. The rule syntax is explained in the man page +for <filename>mime.types</filename> and in the comments section of the +<filename>mime.types</filename> file itself. A simple rule reads +like this: + +<indexterm><primary>application/pdf</primary></indexterm> +<filterline> + application/pdf pdf string(0,%PDF) +</filterline> + +This means if a filename has either a +<filename>.pdf</filename> suffix or if the magic +string <emphasis>%PDF</emphasis> is right at the +beginning of the file itself (offset 0 from the start), then it is +a PDF file (<parameter>application/pdf</parameter>). +Another rule is this: + +<filterline> + application/postscript ai eps ps string(0,%!) string(0,<04>%!) +</filterline> + +If the filename has one of the suffixes +<filename>.ai</filename>, <filename>.eps</filename>, +<filename>.ps</filename> or if the file itself starts with one of the +strings <emphasis>%!</emphasis> or <emphasis><![CDATA[<04>%!]]></emphasis>, it +is a generic PostScript file +(<parameter>application/postscript</parameter>). +</para> + +<warning><para> +Don't confuse the other mime.types files your system might be using +with the one in the <filename>/etc/cups/</filename> directory. +</para></warning> + +<note><para> +There is an important difference between two similar MIME types in +CUPS: one is <parameter>application/postscript</parameter>, the other is +<parameter>application/vnd.cups-postscript</parameter>. While +<parameter>application/postscript</parameter> 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), +<parameter>application/vnd.cups-postscript</parameter> may have the job +options inserted into the PostScript data itself (where +applicable). The transformation of the generic PostScript +(<parameter>application/postscript</parameter>) to the device-specific version +(<parameter>application/vnd.cups-postscript</parameter>) is the responsibility of the +CUPS <parameter>pstops</parameter> filter. pstops uses information +contained in the PPD to do the transformation. +</para></note> + +<para> +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. +</para> +</sect2> + +<sect2> +<title>MIME Type Conversion Rules</title> + + +<para> +<indexterm><primary>MIME</primary></indexterm> +<indexterm><primary>application/pdf</primary></indexterm> +CUPS reads the file <filename>/etc/cups/mime.convs</filename> +(and all other files named with a <filename>*.convs</filename> +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: + +<filterline> + application/pdf application/postscript 33 pdftops +</filterline> + +This means that the <parameter>pdftops</parameter> filter will take +<parameter>application/pdf</parameter> as input and produce +<parameter>application/postscript</parameter> as output; the virtual +cost of this operation is 33 CUPS-$. The next filter is more +expensive, costing 66 CUPS-$: + +<indexterm><primary>pdf</primary></indexterm> + +<filterline> + application/vnd.hp-HPGL application/postscript 66 hpgltops +</filterline> + +This is the <parameter>hpgltops</parameter>, which processes HP-GL +plotter files to PostScript. + +<indexterm><primary>application/octet-stream</primary></indexterm> + +<filterline> + application/octet-stream +</filterline> + +Here are two more examples: + +<indexterm><primary>text/plain</primary></indexterm> + +<filterline> + application/x-shell application/postscript 33 texttops + text/plain application/postscript 33 texttops +</filterline> + +The last two examples name the <parameter>texttops</parameter> filter +to work on <parameter>text/plain</parameter> as well as on <parameter>application/x-shell</parameter>. (Hint: +This differentiation is needed for the syntax highlighting feature of +<parameter>texttops</parameter>). +</para> +</sect2> + +<sect2> +<title>Filtering Overview</title> + + +<para> +<indexterm><primary>MIME</primary></indexterm> +There are many more combinations named in <filename>mime.convs</filename>. However, you +are not limited to use the ones pre-defined there. You can plug in any +filter you like into 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 to what CUPS +needs and put in the right lines in <filename>mime.types</filename> +and <filename>mime.convs</filename>, then it will work seamlessly +inside CUPS. +</para> + +<sect3> +<title>Filter requirements</title> +<para> +The mentioned <quote>CUPS requirements</quote> for filters are simple. Take +filenames or <filename>stdin</filename> as input and write to +<filename>stdout</filename>. They should take these 5 or 6 arguments: +<emphasis>printer job user title copies options [filename]</emphasis> +</para> + +<variablelist> +<varlistentry><term>Printer </term> +<listitem><para>The name of the printer queue (normally this is the +name of the filter being run).</para></listitem> +</varlistentry> + +<varlistentry><term>job </term> +<listitem><para>The numeric job ID for the job being +printed.</para></listitem> +</varlistentry> + +<varlistentry><term>user </term> +<listitem><para>The string from the originating-user-name +attribute.</para></listitem> +</varlistentry> + +<varlistentry><term>title </term> +<listitem><para>The string from the job-name attribute.</para></listitem> +</varlistentry> + +<varlistentry><term>copies </term> +<listitem><para>The numeric value from the number-copies +attribute.</para></listitem> +</varlistentry> + +<varlistentry><term>options </term> +<listitem><para>The job options.</para></listitem> +</varlistentry> + +<varlistentry><term>filename </term> +<listitem><para>(Optionally) The print request file (if missing, +filters expected data fed through <filename>stdin</filename>). In most +cases, it is easy to write a simple wrapper script around existing +filters to make them work with CUPS.</para></listitem> +</varlistentry> +</variablelist> +</sect3> +</sect2> + +<sect2> +<title>Prefilters</title> + + +<para> +<indexterm><primary>PostScript</primary></indexterm> +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. +</para> + +<para> +But what happens if you send one of the supported non-PS formats +to print? Then CUPS runs <quote>pre-filters</quote> on these input formats to +generate PostScript first. There are pre-filters to create PS from +ASCII text, PDF, DVI, or HP-GL. The outcome of these filters is always +of MIME type <parameter>application/postscript</parameter> (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 pre-filter is running on all supported image formats, +the <parameter>imagetops</parameter> filter. Its outcome is always of +MIME type <parameter>application/vnd.cups-postscript</parameter> +(not application/postscript), meaning it has the +print options already embedded into the file. +</para> + +<para> + <image id="small4" scale="25"><imagedescription>Pre-filtering in CUPS to form PostScript.</imagedescription> + <imagefile>4small</imagefile> +</image> +</para> +</sect2> + +<sect2> +<title>pstops</title> + +<para> +<emphasis>pstops</emphasis> is the filter to convert +<parameter>application/postscript</parameter> to <?latex \linebreak ?> +<parameter>application/vnd.cups-postscript</parameter>. It was said +above that 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. +</para> + +<para> + <image scale="25" id="small5"><imagedescription>Adding device-specific print options.</imagedescription> + <imagefile>5small</imagefile> + </image> +</para> + +<para> +This is not all. Other tasks performed by it are: +</para> + +<itemizedlist> +<listitem><para> +Selecting the range of pages to be printed (if you choose to +print only pages <quote>3, 6, 8-11, 16, 19-21</quote>, or only the odd numbered +ones). +</para></listitem> + +<listitem><para> +Putting 2 or more logical pages on one sheet of paper (the +so-called <quote>number-up</quote> function). +</para></listitem> + +<listitem><para>Counting the pages of the job to insert the accounting +information into the <filename>/var/log/cups/page_log</filename>. +</para></listitem> +</itemizedlist> +</sect2> + +<sect2> +<title>pstoraster</title> + +<para> +<parameter>pstoraster</parameter> 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 <emphasis>raster drivers</emphasis> +that are able to generate device-specific printer data. +</para> + +<para> + <image id="small6" scale="25"><imagedescription>PostScript to intermediate raster format.</imagedescription><imagefile>6small</imagefile></image> +</para> + +<para> +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 following 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 +for the first stage of rasterization so these vendors do not need to care +about Ghostscript complications (in fact, there is currently more +than one vendor financing the development of CUPS raster drivers). +</para> + +<para> + <image id="small7"><imagedescription>CUPS-raster production using Ghostscript.</imagedescription> + <imagefile>7small</imagefile> + </image> +</para> + +<para> +CUPS versions before version 1.1.15 were shipping a binary (or source +code) standalone filter, named <parameter>pstoraster</parameter>. <parameter>pstoraster</parameter> was derived +from GNU Ghostscript 5.50, and could be installed besides and in +addition to any GNU or AFPL Ghostscript package without conflicting. +</para> + +<para> +>From version 1.1.15, this has changed. The functions for this have been +integrated back into Ghostscript (now based on GNU Ghostscript version +7.05). The <parameter>pstoraster</parameter> filter is now a simple shell script calling +<command>gs</command> with the <command>-sDEVICE=cups</command> +parameter. If your Ghostscript does not show a success on asking for +<command>gs -h |grep cups</command>, you might not be able to +print. Update your Ghostscript. +</para> +</sect2> + +<sect2> +<title>imagetops and imagetoraster</title> + +<para> +In the section about pre-filters, we mentioned the pre-filter +that generates PostScript from image formats. The <parameter>imagetoraster</parameter> +filter is used to convert directly from image to raster, without the +intermediate PostScript stage. It is used more often than the above +mentioned pre-filters. A summarizing flowchart of image file +filtering is shown in <link linkend="small8">the figure below</link>. +</para> + +<para> + <image id="small8"><imagedescription>Image format to CUPS-raster format conversion.</imagedescription> + <imagefile>8small</imagefile> + </image> +</para> + +</sect2> + +<sect2> +<title>rasterto [printers specific]</title> + +<para> +CUPS ships with quite different raster drivers processing CUPS +raster. On my system I find in /usr/lib/cups/filter/ these: +<parameter>rastertoalps</parameter>, <parameter>rastertobj</parameter>, <parameter>rastertoepson</parameter>, <parameter>rastertoescp</parameter>, +<parameter>rastertopcl</parameter>, <parameter>rastertoturboprint</parameter>, <parameter>rastertoapdk</parameter>, <parameter>rastertodymo</parameter>, +<parameter>rastertoescp</parameter>, <parameter>rastertohp</parameter>, and +<parameter>rastertoprinter</parameter>. Don't worry if you have less +than this; some of these are installed by commercial add-ons to CUPS +(like <parameter>rastertoturboprint</parameter>), others (like +<parameter>rastertoprinter</parameter>) by third-party driver +development projects (such as Gimp-Print) wanting to cooperate as +closely as possible with CUPS. +</para> + +<para> + <image id="small9"><imagedescription>Raster to printer-specific formats.</imagedescription> + <imagefile>9small</imagefile> + </image> +</para> +</sect2> + +<sect2> +<title>CUPS Backends</title> + +<para> +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 of sending printjobs over the network, or for every local +interface. Every CUPS print queue needs to have a CUPS <quote>device-URI</quote> +associated with it. The device URI is the way to encode the backend +used to send the job to its destination. Network device-URIs are using +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 much from my examples, if your OS is not Linux: +</para> + +<variablelist> + <varlistentry><term>usb </term> + <listitem><para> + This backend sends printfiles to USB-connected printers. An + example for the CUPS device-URI to use is: + <filename>usb:/dev/usb/lp0</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>serial </term> + <listitem><para> + This backend sends printfiles to serially connected printers. + An example for the CUPS device-URI to use is: + <filename>serial:/dev/ttyS0?baud=11500</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>parallel </term> + <listitem><para> + This backend sends printfiles to printers connected to the + parallel port. An example for the CUPS device-URI to use is: + <filename>parallel:/dev/lp0</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>scsi </term> + <listitem><para> + This backend sends printfiles to printers attached to the + SCSI interface. An example for the CUPS device-URI to use is: + <filename>scsi:/dev/sr1</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>lpd </term> + <listitem><para> + This backend sends printfiles to LPR/LPD connected network + printers. An example for the CUPS device-URI to use is: + <filename>lpd://remote_host_name/remote_queue_name</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>AppSocket/HP JetDirect </term> + <listitem><para> + This backend sends printfiles to AppSocket (a.k.a. "HP + JetDirect") connected network printers. An example for the CUPS + device-URI to use is: + <filename>socket://10.11.12.13:9100</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>ipp </term> + <listitem><para> + This backend sends printfiles to IPP connected network + printers (or to other CUPS servers). Examples for CUPS device-URIs + to use are: + <filename>ipp:://192.193.194.195/ipp</filename> + (for many HP printers) or + <filename>ipp://remote_cups_server/printers/remote_printer_name</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>http </term> + <listitem><para> + This backend sends printfiles 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: + <filename>http:://192.193.194.195:631/ipp</filename> + (for many HP printers) or + <filename>http://remote_cups_server:631/printers/remote_printer_name</filename>. + </para></listitem></varlistentry> + + <varlistentry><term>smb </term> + <listitem><para> + This backend sends printfiles to printers shared by a Windows + host. An example for CUPS device-URIs that may be used includes: + </para> + + <para> + <simplelist> + <member><filename>smb://workgroup/server/printersharename</filename></member> + <member><filename>smb://server/printersharename</filename></member> + <member><filename>smb://username:password@workgroup/server/printersharename</filename></member> + <member><filename>smb://username:password@server/printersharename</filename></member> + </simplelist> + </para> + + <para> + The smb:// backend is a symlink to the Samba utility + <parameter>smbspool</parameter> (does not ship with CUPS). If the + symlink is not present in your CUPS backend directory, have your + root user create it: <command>ln -s `which smbspool' + /usr/lib/cups/backend/smb</command>. + </para></listitem></varlistentry> +</variablelist> + +<para> +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 <quote>special</quote> printers that send +the printjobs as email (through a <quote>mailto:/</quote> backend), convert them to +PDF (through a <quote>pdfgen:/</quote> backend) or dump them to <quote>/dev/null</quote>. (In +fact I have the system-wide default printer set up to be connected to +a devnull:/ backend: there are just too many people sending jobs +without specifying a printer, or scripts and programs which do not name +a printer. The system-wide default deletes the job and sends a polite +email back to the $USER asking him to always specify the correct +printer name.) +</para> + +<para> +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 <emphasis>lpinfo</emphasis> +utility. Used with the <option>-v</option> parameter, it lists +all available backends: +</para> + +<para><screen> +&prompt;<userinput>lpinfo -v</userinput> +</screen></para> +</sect2> + +<sect2> +<title>The Role of <parameter>cupsomatic/foomatic</parameter></title> + +<para> +<indexterm><primary>cupsomatic</primary></indexterm> +<indexterm><primary>foomatic</primary></indexterm> +<parameter>cupsomatic</parameter> filters may be the most widely used on CUPS +installations. You must be clear about the fact 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. <parameter>cupsomatic</parameter> uses PPDs that are generated from the Foomatic +Printer & Driver Database at Linuxprinting.org. +</para> + +<para> +You can recognize these PPDs from the line calling the +<parameter>cupsomatic</parameter> filter: + +<filterline> + *cupsFilter: "application/vnd.cups-postscript 0 cupsomatic" +</filterline> + +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 <parameter>foomatic</parameter> namepart for +the driver description. <parameter>cupsomatic</parameter> is a Perl script that runs +Ghostscript with all the complicated command line options +auto-constructed from the selected PPD and command line options give to +the printjob. +</para> + +<para> +<indexterm><primary>point 'n' print</primary></indexterm> + However, <parameter>cupsomatic</parameter> 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 <quote>Point'n'Print</quote> to Windows clients. A better +and more powerful successor is now in a stable beta-version: it is called <parameter>foomatic-rip</parameter>. To use +<parameter>foomatic-rip</parameter> as a filter with CUPS, you need the new-type PPDs. These +have a similar but different line: + +<filterline> + *cupsFilter: "application/vnd.cups-postscript 0 foomatic-rip" +</filterline> + +The PPD generating engine at Linuxprinting.org has been revamped. +The new PPDs comply to the Adobe spec. On top, 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 the new foomatic-rip now 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. +</para> +</sect2> + +<sect2> +<title>The Complete Picture</title> + +<para> +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 document. +</para> +</sect2> + +<sect2> +<title><filename>mime.convs</filename></title> + +<para> +CUPS auto-constructs all possible filtering chain paths for any given +MIME type, and every printer installed. But how does it decide in +favor or against a specific alternative? (There may often 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 <quote>filter cost.</quote> CUPS decides for the most <quote>inexpensive</quote> route. +</para> + +<tip><para> +The setting of <parameter>FilterLimit 1000</parameter> in +<filename>cupsd.conf</filename> 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 <quote>FilterLimit</quote> 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. +</para></tip> +</sect2> + +<sect2> + <title><quote>Raw</quote> Printing</title> + +<para> + You can tell CUPS to print (nearly) any file <quote>raw</quote>. <quote>Raw</quote> means it + will not be filtered. CUPS will send the file to the printer <quote>as is</quote> +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 <quote><parameter>-o raw</parameter></quote> 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: +</para> + +<para><screen> +&prompt;<userinput>lpadmin -P rawprinter -v socket://11.12.13.14:9100 -E</userinput> +</screen></para> + +<para> + sets up a queue named <quote>rawprinter</quote>, connected via the <quote>socket</quote> + protocol (a.k.a. <quote>HP JetDirect</quote>) to the device at IP address +11.12.1.3.14, using port 9100. (If you had added a PPD with +<command>-P /path/to/PPD</command> to this command line, you would +have installed a <quote>normal</quote> print queue. +</para> + +<para> +CUPS will automatically treat each job sent to a queue as a <quote>raw</quote> 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. +</para> +</sect2> + +<sect2> +<title>application/octet-stream Printing</title> + +<para> +Any MIME type with no rule in the +<filename>/etc/cups/mime.types</filename> file is regarded as unknown +or <parameter>application/octet-stream</parameter> and will not be +sent. Because CUPS refuses to print unknown MIME types per default, +you will probably have experienced the fact that print jobs originating +from Windows clients were not printed. You may have found an error +message in your CUPS logs like: +</para> + +<para><computeroutput> + Unable to convert file 0 to printable format for job +</computeroutput></para> + +<para> +To enable the printing of <parameter>application/octet-stream</parameter> files, edit +these two files: +</para> + +<itemizedlist> +<listitem><para><filename>/etc/cups/mime.convs</filename></para></listitem> + +<listitem><para><filename>/etc/cups/mime.types</filename></para></listitem> +</itemizedlist> + +<para> +Both contain entries (at the end of the respective files) which must +be uncommented to allow RAW mode operation for +<parameter>application/octet-stream</parameter>. In <filename>/etc/cups/mime.types</filename> +make sure this line is present: + +<indexterm><primary>application/octet-stream</primary></indexterm> + +<filterline> +application/octet-stream +</filterline> + +This line (with no specific auto-typing rule set) makes all files +not otherwise auto-typed a member of <parameter>application/octet-stream</parameter>. In +<filename>/etc/cups/mime.convs</filename>, have this +line: + +<filterline> +application/octet-stream application/vnd.cups-raw 0 - +</filterline> + +<indexterm><primary>MIME</primary></indexterm> + +This line tells CUPS to use the <emphasis>Null Filter</emphasis> +(denoted as <quote>-</quote>, doing nothing at all) on +<parameter>application/octet-stream</parameter>, and tag the result as +<parameter>application/vnd.cups-raw</parameter>. 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. +</para> + +<note><para>Editing the <filename>mime.convs</filename> and the +<filename>mime.types</filename> file does not +<emphasis>enforce</emphasis> <quote>raw</quote> printing, it only +<emphasis>allows</emphasis> it. +</para></note> + +<formalpara> +<title>Background</title> + +<para> +CUPS being 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...) <quote>Unknown</quote> data are regarded by CUPS +as <emphasis>MIME type</emphasis> +<emphasis>application/octet-stream</emphasis>. While you +<emphasis>can</emphasis> send data <quote>raw</quote>, the MIME type for these must +be one that is known to CUPS and an allowed one. The file +<filename>/etc/cups/mime.types</filename> defines the <quote>rules</quote> of how CUPS +recognizes MIME types. The file +<filename>/etc/cups/mime.convs</filename> decides which file +conversion filter(s) may be applied to which MIME types. +</para> +</formalpara> +</sect2> + +<sect2> +<title>PostScript Printer Descriptions (PPDs) for Non-PS Printers</title> + + +<para> +<indexterm><primary>PPD</primary></indexterm> +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 jobfile. 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 jobfiles. The only difference is: +a PostScript printer has the RIP built-in, for other types of +printers the Ghostscript RIP runs on the host computer. +</para> + +<para> +PPDs for a non-PS printer have a few lines that are unique to +CUPS. The most important one looks similar to this: + +<indexterm><primary>application/vnd.cups-raster</primary></indexterm> + +<filterline> + *cupsFilter: application/vnd.cups-raster 66 rastertoprinter +</filterline> + +It is the last piece in the CUPS filtering puzzle. This line tells the +CUPS daemon to use as a last filter <parameter>rastertoprinter</parameter>. This filter +should be served as input an <parameter>application/vnd.cups-raster</parameter> MIME type +file. Therefore, CUPS should auto-construct a filtering chain, which +delivers as its last output the specified MIME type. This is then +taken as input to the specified <parameter>rastertoprinter</parameter> filter. After this +the last filter has done its work (<parameter>rastertoprinter</parameter> is a Gimp-Print +filter), the file should go to the backend, which sends it to the +output device. +</para> + +<para> +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 <link linkend="cups-ppds">the figure below</link> for summary information. +</para> + +<table frame="all" id="cups-ppds"> + <title>PPDs shipped with CUPS</title> + <tgroup cols="2" align="left"> + <colspec align="left"/> + <colspec align="justify" colwidth="1*"/> + <thead><row><entry>PPD file</entry><entry>Printer type</entry></row></thead> + <tbody> + <row><entry>deskjet.ppd</entry><entry>older HP inkjet printers and compatible</entry></row> + + <row><entry>deskjet2.ppd</entry> <entry>newer HP inkjet printers and compatible </entry> </row> + + <row><entry>dymo.ppd</entry> <entry>label printers </entry> </row> + + <row><entry>epson9.ppd</entry> <entry>Epson 24pin impact printers and compatible </entry> </row> + + <row><entry>epson24.ppd</entry> <entry>Epson 24pin impact printers and compatible </entry> </row> + + <row><entry>okidata9.ppd</entry> <entry>Okidata 9pin impact printers and compatible </entry> </row> + + <row><entry>okidat24.ppd</entry> <entry>Okidata 24pin impact printers and compatible </entry> </row> + + <row><entry>stcolor.ppd</entry> <entry>older Epson Stylus Color printers </entry> </row> + + <row><entry>stcolor2.ppd</entry> <entry>newer Epson Stylus Color printers </entry> </row> + + <row><entry>stphoto.ppd</entry> <entry>older Epson Stylus Photo printers </entry> </row> + + <row><entry>stphoto2.ppd</entry> <entry>newer Epson Stylus Photo printers </entry> </row> + + <row><entry>laserjet.ppd</entry> <entry>all PCL printers. Further below is a discussion + of several other driver/PPD-packages suitable for use with CUPS. </entry> </row> + + </tbody> + </tgroup> +</table> + +</sect2> + +<sect2> +<title><emphasis>cupsomatic/foomatic-rip</emphasis> Versus <emphasis>native CUPS</emphasis> Printing</title> + + +<para> +<indexterm><primary>cupsomatic</primary></indexterm> +<indexterm><primary>foomatic-rip</primary></indexterm> +Native CUPS rasterization works in two steps: +</para> + +<itemizedlist> +<listitem><para> +First is the <parameter>pstoraster</parameter> step. It uses the special CUPS +<indexterm><primary>ESP</primary><secondary>Ghostscript</secondary></indexterm> +device from ESP Ghostscript 7.05.x as its tool. +</para></listitem> + +<listitem><para> +Second comes the <parameter>rasterdriver</parameter> 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/non-free and some are proprietary.</para></listitem> +</itemizedlist> + +<para> +Often this produces better quality (and has several more +advantages) than other methods. +</para> + +<para> + <image id="cupsomatic-dia"><imagedescription>cupsomatic/foomatic Processing versus Native CUPS.</imagedescription> + <imagefile>10small</imagefile> + </image> +</para> + +<para> +One other method is the <parameter>cupsomatic/foomatic-rip</parameter> +way. Note that <parameter>cupsomatic</parameter> is <emphasis>not</emphasis> made by the CUPS +developers. It is an independent contribution to printing development, +made by people from Linuxprinting.org <footnote><para>see also <ulink + noescape="1" url="http://www.cups.org/cups-help.html">http://www.cups.org/cups-help.html</ulink></para></footnote>. +<parameter>cupsomatic</parameter> is no longer developed and maintained and is no longer +supported. It has now been replaced by +<parameter>foomatic-rip</parameter>. <parameter>foomatic-rip</parameter> is a complete re-write +of the old <parameter>cupsomatic</parameter> idea, but very much improved and generalized to +other (non-CUPS) spoolers. An upgrade to foomatic-rip is strongly +advised, especially if you are upgrading to a recent version of CUPS, +too. +</para> + +<para> + <indexterm><primary>cupsomatic</primary></indexterm> + <indexterm><primary>foomatic</primary></indexterm> +Both the <parameter>cupsomatic</parameter> (old) and the <parameter>foomatic-rip</parameter> (new) methods from +Linuxprinting.org use 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. +</para> + +<para> +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. +</para> + +<para> +<parameter>cupsomatic</parameter> kidnaps the printfile after the +<parameter>application/vnd.cups-postscript</parameter> stage and +deviates it through the CUPS-external, system-wide Ghostscript +installation. Therefore the printfile bypasses the <parameter>pstoraster</parameter> filter +(and also bypasses the CUPS-raster-drivers +<parameter>rastertosomething</parameter>). After Ghostscript finished its rasterization, +<parameter>cupsomatic</parameter> hands the rendered file directly to the CUPS backend. The +flowchart in <link linkend="cupsomatic-dia">the image below</link> illustrates the difference between native CUPS +rendering and the <parameter>Foomatic/cupsomatic</parameter> method. +</para> +</sect2> + +<sect2> +<title>Examples for Filtering Chains</title> + +<para> +Here are a few examples of commonly occurring filtering chains to +illustrate the workings of CUPS. +</para> + +<para> +Assume you want to print a PDF file to an HP JetDirect-connected +PostScript printer, but you want to print the pages 3-5, 7, 11-13 +only, and you want to print them <quote>two-up</quote> and <quote>duplex</quote>: +</para> + +<itemizedlist> +<listitem><para>Your print options (page selection as required, two-up, +duplex) are passed to CUPS on the command line.</para></listitem> + +<listitem><para>The (complete) PDF file is sent to CUPS and autotyped as +<parameter>application/pdf</parameter>.</para></listitem> + +<listitem><para>The file therefore must first pass the +<parameter>pdftops</parameter> pre-filter, which produces PostScript +MIME type <parameter>application/postscript</parameter> (a preview here +would still show all pages of the original PDF).</para></listitem> + +<listitem><para>The file then passes the <parameter>pstops</parameter> +filter that applies the command line options: it selects the pages +2-5, 7 and 11-13, creates an imposed layout <quote>2 pages on 1 sheet</quote> and +inserts the correct <quote>duplex</quote> command (as defined in the printer's +PPD) into the new PostScript file; the file is now of PostScript MIME +type +<parameter>application/vnd.cups-postscript</parameter>.</para></listitem> + +<listitem><para>The file goes to the <parameter>socket</parameter> +backend, which transfers the job to the printers.</para></listitem> +</itemizedlist> + +<para> + The resulting filter chain, therefore, is as drawn in <link linkend="pdftosocket">the figure below</link>. +</para> + +<image id="pdftosocket"><imagefile>pdftosocket</imagefile><imagedescription>PDF to socket chain.</imagedescription></image> + +<para> +Assume your want to print the same filter to an USB-connected +Epson Stylus Photo printer installed with the CUPS +<filename>stphoto2.ppd</filename>. The first few filtering stages +are nearly the same: +</para> + +<itemizedlist> +<listitem><para>Your print options (page selection as required, two-up, +duplex) are passed to CUPS on the commandline.</para></listitem> + +<listitem><para>The (complete) PDF file is sent to CUPS and autotyped as +<parameter>application/pdf</parameter>.</para></listitem> + +<listitem><para>The file must first pass the +<parameter>pdftops</parameter> pre-filter, which produces PostScript +MIME type <parameter>application/postscript</parameter> (a preview here +would still show all pages of the original PDF).</para></listitem> + +<listitem><para>The file then passes the <quote>pstops</quote> filter that applies +the commandline options: it selects the pages 2-5, 7 and 11-13, +creates an imposed layout <quote>two pages on one sheet</quote> and inserts the +correct <quote>duplex</quote> command... (Oops &smbmdash; this printer and PPD +do not support duplex printing at all &smbmdash; so this option will +be ignored) into the new PostScript file; the file is now of PostScript +MIME type +<parameter>application/vnd.cups-postscript</parameter>.</para></listitem> + +<listitem><para>The file then passes the + <!--FIXME--> +<parameter>pstoraster</parameter> stage and becomes MIME type +<parameter>application/ +cups-raster</parameter>.</para></listitem> + +<listitem><para>Finally, the <parameter>rastertoepson</parameter> filter +does its work (as indicated in the printer's PPD), creating the +rinter-specific raster data and embedding any user-selected +print-options into the print data stream.</para></listitem> + +<listitem><para>The file goes to the <parameter>usb</parameter> backend, +which transfers the job to the printers.</para></listitem> +</itemizedlist> + +<para> + The resulting filter chain therefore is as drawn in <link linkend="pdftoepsonusb">the figure below</link>. +</para> + +<image id="pdftoepsonusb"><imagefile>pdftoepsonusb</imagefile><imagedescription>PDF to USB chain.</imagedescription></image> +</sect2> + +<sect2> +<title>Sources of CUPS Drivers/PPDs</title> + +<para> +On the Internet you can now find many thousands of CUPS-PPD files +(with their companion filters), in many national languages +supporting more than thousand non-PostScript models. +</para> + +<itemizedlist> +<indexterm><primary>ESP</primary><secondary>Print Pro</secondary></indexterm> +<indexterm><primary>PrintPro</primary><see>ESP Print Pro</see></indexterm> +<listitem><para><ulink url="http://wwwl.easysw.com/printpro/">ESP +PrintPro</ulink> (commercial, +non-free) is packaged with more than three thousand PPDs, ready for +successful use <quote>out of the box</quote> on Linux, Mac OS X, IBM-AIX, +HP-UX, Sun-Solaris, SGI-IRIX, Compaq Tru64, Digital UNIX, and some +more 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).</para></listitem> + +<listitem><para>The <ulink +url="http://gimp-print.sourceforge.net/">Gimp-Print-Project +</ulink> (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.</para></listitem> + +<listitem><para><ulink url="http://www.turboprint.com/">TurboPrint +</ulink> (shareware, non-free) supports +roughly the same amount of printers in excellent +quality.</para></listitem> + +<listitem><para><ulink +url="http://www-124.ibm.com/developerworks/oss/linux/projects/omni/">OMNI +</ulink> +(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).</para></listitem> + +<listitem><para><ulink url="http://hpinkjet.sourceforge.net/">HPIJS +</ulink> (BSD-style licenses, free) +supports around 150 of HP's own printers and is also providing +excellent print quality now (currently available only via the Foomatic +path).</para></listitem> + +<listitem><para><ulink +url="http://www.linuxprinting.org/">Foomatic/cupsomatic +</ulink> (LPGL, free) from +Linuxprinting.org are providing PPDs for practically every Ghostscript +filter known to the world (including Omni, Gimp-Print and +HPIJS).</para></listitem> +</itemizedlist> + +</sect2> + +<sect2> +<title>Printing with Interface Scripts</title> + +<para> +CUPS also supports the usage of <quote>interface scripts</quote> 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 similar role as +PPDs for PostScript printers. Interface scripts may inject the Escape +sequences as required into the print data stream, if the user has +chosen to select a certain paper tray, or print landscape, or use A3 +paper, etc. Interfaces 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 <command>-i</command> option: +</para> + +<para><screen> +&rootprompt;<userinput>lpadmin -p pclprinter -v socket://11.12.13.14:9100 \ + -i /path/to/interface-script</userinput> +</screen></para> + +<para> +Interface scripts might be the <quote>unknown animal</quote> 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 usage of interface scripts is +to be found at <ulink + noescape="1" url="http://playground.sun.com/printing/documentation/interface.html">http://playground.sun.com/printing/documentation/interface.html</ulink>). +</para> +</sect2> +</sect1> + +<sect1> + <title>Network Printing (Purely Windows)</title> + +<para> +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 <quote>purely Windows</quote> setup: Windows clients +with a Windows NT print server. +</para> + +<sect2> +<title>From Windows Clients to an NT Print Server</title> + +<para> +Windows clients printing to an NT-based print server have two +options. They may: +<indexterm><primary>GDI</primary></indexterm> +<indexterm><primary>EMF</primary></indexterm> +</para> + + +<itemizedlist> + <listitem><para>Execute the driver locally and render the GDI output + (EMF) into the printer-specific format on their own. + </para></listitem> + + <listitem><para>Send the GDI output (EMF) to the server, where the +driver is executed to render the printer specific +output.</para></listitem> +</itemizedlist> + +<para> + Both print paths are shown in the flowcharts in the figures below. +</para> +</sect2> + +<sect2> +<title>Driver Execution on the Client</title> + +<para> +In the first case the print server must spool the file as raw, +meaning it shouldn't touch the jobfile 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 <quote>spooling-only</quote> print server may +be used even if no driver(s) for UNIX are available it is sufficient +to have the Windows client drivers available; and installed on the +clients. +</para> + +<para> + <image id="small11"><imagedescription>Print driver execution on the client.</imagedescription> + <imagefile>11small</imagefile> + </image> +</para> +</sect2> + +<sect2> +<title>Driver Execution on the Server</title> + + +<para> +<indexterm><primary>PostScript</primary></indexterm> +<indexterm><primary>PCL</primary></indexterm> +<indexterm><primary>ESC/P</primary></indexterm> +<indexterm><primary>EMF</primary></indexterm> +<indexterm><primary>GDI</primary></indexterm> +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. +</para> + +<para> + <image id="small12"><imagedescription>Print driver execution on the server.</imagedescription> + <imagefile>12small</imagefile> + </image> +</para> + +<para> +However, there is something similar possible with CUPS. Read on. +</para> +</sect2> +</sect1> + +<sect1> +<title>Network Printing (Windows Clients &smbmdash; UNIX/Samba Print +Servers)</title> + +<para> +Since UNIX print servers <emphasis>cannot</emphasis> 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. +</para> + +<sect2> +<title>From Windows Clients to a CUPS/Samba Print Server</title> + +<para> +Here is a simple recipe showing how you can take advantage of CUPS' +powerful features for the benefit of your Windows network printing +clients: +</para> + +<itemizedlist> + +<listitem><para>Let the Windows clients send PostScript to the CUPS +server.</para></listitem> + +<listitem><para>Let the CUPS server render the PostScript into device-specific raster format.</para></listitem> +</itemizedlist> + +<para> +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. +</para> + +<para> +First, to enable CUPS-based rinting through Samba the +following options should be set in your &smb.conf; file [global] +section: +</para> + +<smbconfblock> +<smbconfoption><name>printing</name><value>cups</value></smbconfoption> +<smbconfoption><name>printcap</name><value>cups</value></smbconfoption> +</smbconfblock> + +<para> +When these parameters are specified, all manually set print directives +(like <smbconfoption><name>print command</name></smbconfoption>, or <smbconfoption><name>lppause command</name></smbconfoption>) in &smb.conf; (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 +<emphasis>System V</emphasis> AT&T command set, with the -oraw +option automatically passing through (if you want your own defined +print commands to work with a Samba that has CUPS support compiled in, +simply use <smbconfoption><name>printing</name><value>sysv</value></smbconfoption>). +</para> + +<para> +<image id="small13"><imagedescription>Printing via CUPS/Samba server.</imagedescription> + <imagefile>13small</imagefile> +</image> +</para> +</sect2> + +<sect2> +<title>Samba Receiving Jobfiles and Passing Them to CUPS</title> + +<para> +Samba <emphasis>must</emphasis> use its own spool directory (it is set +by a line similar to <smbconfoption><name>path</name><value>/var/spool/samba</value></smbconfoption>, +in the <smbconfsection>[printers]</smbconfsection> or +<smbconfsection>[printername]</smbconfsection> section of +&smb.conf;). Samba receives the job in its own +spool space and passes it into the spool directory of CUPS (the CUPS +spooling directory is set by the <parameter>RequestRoot</parameter> +directive, in a line that defaults to <parameter>RequestRoot +/var/spool/cups</parameter>). CUPS checks the access rights of its +spool dir and resets it to healthy values with every restart. We have +seen quite a few people who had used a common spooling space for Samba +and CUPS, and were struggling for weeks with this <quote>problem.</quote> +</para> + +<para> +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 <quote>localhost</quote> to print. If they run on different machines, you +need to make sure the Samba host gets access to printing on CUPS. +</para> +</sect2> +</sect1> + +<sect1> +<title>Network PostScript RIP</title> + +<para> +This section discusses the use of CUPS filters on the server &smbmdash; configuration where +clients make use of a PostScript driver with CUPS-PPDs. +</para> + + +<para> +<indexterm><primary>PostScript</primary></indexterm> +<indexterm><primary>PCL</primary></indexterm> +<indexterm><primary>PJL</primary></indexterm> +PPDs can control all print device options. They are usually provided +by the manufacturer, if you own a PostScript printer, that is. PPD +files (PostScript Printer Descriptions) 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 +<quote>on-the-fly</quote> into buttons and drop-down lists for the user to select. +</para> + +<para> +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 <ulink +noescape="1" url="http://localhost:631/printers/">http://localhost:631/printers/</ulink> +and click on one <guibutton>Configure Printer</guibutton> button to see +it), or a command line interface (see <command>man lpoptions</command> +or see if you have <command>lphelp</command> on your system). There are also some +different GUI frontends 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. +</para> + +<sect2> +<title>PPDs for Non-PS Printers on UNIX</title> + + +<para> +<indexterm><primary>PPD</primary></indexterm> +CUPS does not limit itself to <quote>real</quote> PostScript printers in its usage +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. +</para> + +<para> +This is logical, as 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 +<parameter>*cupsFilter</parameter>. 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. +</para> +</sect2> + +<sect2> +<title>PPDs for Non-PS Printers on Windows</title> + +<para> +<indexterm><primary>PPD</primary></indexterm> +CUPS-PPDs can also be used on Windows-Clients, on top of a +<quote>core</quote> PostScript driver (now recommended is the "CUPS PostScript +Driver for WindowsNT/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: +</para> + +<itemizedlist> + +<listitem><para>Act as a networked PostScript RIP (Raster Image +Processor), handling printfiles from all client platforms in a uniform +way.</para></listitem> + +<listitem><para>Act as a central accounting and billing server, since +all files are passed through the pstops filter and are, therefore, +logged in the CUPS <filename>page_log</filename> file. +<emphasis>Note:</emphasis> this cannot happen with <quote>raw</quote> print jobs, +which always remain unfiltered per definition.</para></listitem> + +<listitem><para>Enable clients to consolidate on a single PostScript +driver, even for many different target printers.</para></listitem> +</itemizedlist> + +<para> +Using CUPS PPDs on Windows clients enables these to control +all print job settings just as a UNIX client can do. +</para> +</sect2> +</sect1> + +<sect1> +<title>Windows Terminal Servers (WTS) as CUPS Clients</title> + +<para> +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. +</para> + +<sect2> +<title>Printer Drivers Running in <quote>Kernel Mode</quote> Cause Many +Problems</title> + +<para> + In Windows NT printer drivers which run in <quote>Kernel +Mode</quote>, introduces 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 <quote>blue screens +of death</quote> on a regular basis? +</para> + +<para> +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 there have been so far only two different PostScript +drivers: the ones 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. +</para> +</sect2> + +<sect2> +<title>Workarounds Impose Heavy Limitations</title> + +<para> +In many cases, in an attempt to work around this problem, 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 clients in the number of printer options +available for them. 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! +</para> +</sect2> + +<sect2> +<title>CUPS: A <quote>Magical Stone</quote>?</title> + + +<para> +<indexterm><primary>PPD</primary></indexterm> +<indexterm><primary>PostScript</primary></indexterm> +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 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) +chose 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 <quote>raw spooling</quote> device. Plus, this setup is not yet widely tested, +although the first feedbacks look very promising. +</para> +</sect2> + +<sect2> +<title>PostScript Drivers with No Major Problems &smbmdash; Even in Kernel +Mode</title> + +<para> +<indexterm><primary>DDK</primary></indexterm> +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 <quote>2</quote> of <quote>W32X86</quote> are <quote>old</quote> +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 <quote>diff</quote> under the GPL, and if you are +the owner of an <quote>MS DDK for Windows NT,</quote> you can check the driver yourself. +</para> +</sect2> +</sect1> + +<sect1> +<title>Configuring CUPS for Driver Download</title> + +<para> +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 the previous chapter. In reality, this is a +pure Samba business and only relates to the Samba/Windows client +relationship. +</para> + +<sect2> +<title><emphasis>cupsaddsmb</emphasis>: The Unknown Utility</title> + + +<para> +<indexterm><primary>cupsaddsmb</primary></indexterm> +The <command>cupsaddsmb</command> utility (shipped with all current CUPS versions) is an +alternate method to transfer printer drivers into the Samba +<smbconfsection>[print$]</smbconfsection> share. Remember, this share is where +clients expect drivers deposited and setup for download and +installation. It makes the sharing of any (or all) installed CUPS +printers quite easy. <command>cupsaddsmb</command> can use the Adobe PostScript driver as +well as the newly developed CUPS PostScript Driver for +Windows NT/200x/XP. <parameter>cupsaddsmb</parameter> does +<emphasis>not</emphasis> work with arbitrary vendor printer drivers, +but only with the <emphasis>exact</emphasis> driver files that are +named in its man page. +</para> + +<para> +The CUPS printer driver is available from the CUPS download site. Its +package name is <filename>cups-samba-[version].tar.gz</filename> . It +is preferred over the Adobe drivers since it has a number of +advantages: +</para> + +<itemizedlist> +<listitem><para>It supports a much more accurate page +accounting.</para></listitem> + +<listitem><para>It supports banner pages, and page labels on all +printers.</para></listitem> + +<listitem><para>It supports the setting of a number of job IPP +attributes (such as job-priority, page-label and +job-billing).</para></listitem> +</itemizedlist> + +<para> +However, currently only Windows NT, 2000 and XP are supported by the +CUPS drivers. You will also need to get the respective part of Adobe driver +if you need to support Windows 95, 98 and ME clients. +</para> +</sect2> + +<sect2> + <title>Prepare Your &smb.conf; for <command>cupsaddsmb</command></title> + +<para> +Prior to running <command>cupsaddsmb</command>, you need the settings in +&smb.conf; as shown in <link linkend="cupsadd-ex"/>: +</para> + +<para><smbconfexample id="cupsadd-ex"> +<title>smb.conf for cupsaddsmb usage</title> +<smbconfsection>[global]</smbconfsection> +<smbconfoption><name>load printers</name><value>yes</value></smbconfoption> +<smbconfoption><name>printing</name><value>cups</value></smbconfoption> +<smbconfoption><name>printcap name</name><value>cups</value></smbconfoption> + +<smbconfsection>[printers]</smbconfsection> +<smbconfoption><name>comment</name><value>All Printers</value></smbconfoption> +<smbconfoption><name>path</name><value>/var/spool/samba</value></smbconfoption> +<smbconfoption><name>browseable</name><value>no</value></smbconfoption> +<smbconfoption><name>public</name><value>yes</value></smbconfoption> +<smbconfcomment>setting depends on your requirements</smbconfcomment> +<smbconfoption><name>guest ok</name><value>yes</value></smbconfoption> +<smbconfoption><name>writable</name><value>no</value></smbconfoption> +<smbconfoption><name>printable</name><value>yes</value></smbconfoption> +<smbconfoption><name>printer admin</name><value>root</value></smbconfoption> + <smbconfsection>[print$]</smbconfsection> +<smbconfoption><name>comment</name><value>Printer Drivers</value></smbconfoption> +<smbconfoption><name>path</name><value>/etc/samba/drivers</value></smbconfoption> +<smbconfoption><name>browseable</name><value>yes</value></smbconfoption> +<smbconfoption><name>guest ok</name><value>no</value></smbconfoption> +<smbconfoption><name>read only</name><value>yes</value></smbconfoption> +<smbconfoption><name>write list</name><value>root</value></smbconfoption> +</smbconfexample></para> +</sect2> + +<sect2> +<title>CUPS <quote>PostScript Driver for Windows NT/200x/XP</quote></title> + +<para> +<indexterm><primary>PostScript</primary></indexterm> +CUPS users may get the exact same packages from <ulink +noescape="1" url="http://www.cups.org/software.html">http://www.cups.org/software.html</ulink>. +It is a separate package from the CUPS base software files, tagged as +CUPS 1.1.x Windows NT/200x/XP Printer Driver for Samba +(tar.gz, 192k). The filename to download is +<filename>cups-samba-1.1.x.tar.gz</filename>. Upon untar and unzipping, +it will reveal these files: +</para> + +<para><screen> +&rootprompt;<userinput>tar xvzf cups-samba-1.1.19.tar.gz</userinput> +cups-samba.install +cups-samba.license +cups-samba.readme +cups-samba.remove +cups-samba.ss +</screen></para> + +<para> +<indexterm><primary>ESP</primary><secondary>meta packager</secondary></indexterm> +<indexterm><primary>EPM</primary><see>ESP meta packager</see></indexterm> +These have been packaged with the ESP meta packager software +EPM. The <filename>*.install</filename> and +<filename>*.remove</filename> files are simple shell scripts, which +untars the <filename>*.ss</filename> (the <filename>*.ss</filename> is +nothing else but a tar-archive, which can be untarred by <quote>tar</quote> +too). Then it puts the content into +<filename>/usr/share/cups/drivers/</filename>. This content includes three +files: +</para> + +<para><screen> +&rootprompt;<userinput>tar tv cups-samba.ss</userinput> +cupsdrvr.dll +cupsui.dll +cups.hlp +</screen></para> + +<para> +The <parameter>cups-samba.install</parameter> shell scripts are easy to +handle: +</para> + +<para><screen> +&rootprompt;<userinput>./cups-samba.install</userinput> +[....] +Installing software... +Updating file permissions... +Running post-install commands... +Installation is complete. +</screen></para> + +<para> +The script should automatically put the driver files into the +<filename>/usr/share/cups/drivers/</filename> directory. +</para> + +<warning><para> +Due to a bug, one recent CUPS release puts the +<filename>cups.hlp</filename> driver file +into<filename>/usr/share/drivers/</filename> instead of +<filename>/usr/share/cups/drivers/</filename>. To work around this, +copy/move the file (after running the +<command>./cups-samba.install</command> script) manually to the +correct place. +</para></warning> + +<para><screen> +&rootprompt;<userinput>cp /usr/share/drivers/cups.hlp /usr/share/cups/drivers/</userinput> +</screen></para> + + +<para> +<indexterm><primary>DDK</primary></indexterm> +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 Driver +Developer Kit (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 <quote>diff</quote> in source code under the GPL, so anybody with a license of +Visual Studio and a DDK will be able to compile for him/herself. +</para> +</sect2> + +<sect2> +<title>Recognizing Different Driver Files</title> + +<para> +The CUPS drivers do not support the older Windows 95/98/Me, but only +the Windows NT/2000/XP client. +</para> + +<para>Windows NT, 2000 and XP are supported by:</para> + +<para> + <itemizedlist> + <listitem><para>cups.hlp</para></listitem> + <listitem><para>cupsdrvr.dll</para></listitem> + <listitem><para>cupsui.dll</para></listitem> + </itemizedlist> +</para> + +<para> +Adobe drivers are available for the older Windows 95/98/Me as well as +the Windows NT/2000/XP clients. The set of files is different from the +different platforms. +</para> + +<para>Windows 95, 98 and ME are supported by:</para> + +<para> + <itemizedlist> + <listitem><para>ADFONTS.MFM</para></listitem> + <listitem><para>ADOBEPS4.DRV</para></listitem> + <listitem><para>ADOBEPS4.HLP</para></listitem> + <listitem><para>DEFPRTR2.PPD</para></listitem> + <listitem><para>ICONLIB.DLL</para></listitem> + <listitem><para>PSMON.DLL</para></listitem> +</itemizedlist> +</para> + +<para>Windows NT, 2000 and XP are supported by:</para> + +<para> +<itemizedlist> + <listitem><para>ADOBEPS5.DLL</para></listitem> + <listitem><para>ADOBEPSU.DLL</para></listitem> + <listitem><para>ADOBEPSU.HLP</para></listitem> +</itemizedlist> + +</para> + +<note><para> +If both the Adobe driver files and the CUPS driver files for the +support of Windows NT/200x/XP are present in FIXME, the Adobe ones will be ignored +and the CUPS ones will be used. If you prefer &smbmdash; for whatever reason +&smbmdash; to use Adobe-only drivers, move away the three CUPS driver files. The +Windows 9x/Me clients use the Adobe drivers in any case. +</para></note> +</sect2> + +<sect2> +<title>Acquiring the Adobe Driver Files</title> + +<para> +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. Probably you 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 +<smbconfsection>[print$]</smbconfsection> share holds the Adobe files, from +where you can get them with smbclient from the CUPS host. +</para> +</sect2> + +<sect2> +<title>ESP Print Pro PostScript Driver for Windows NT/200x/XP</title> + + + +<para> +<indexterm><primary>ESP</primary><secondary>Print Pro</secondary></indexterm> +Users of the ESP Print Pro software are able to install their Samba +drivers package for this purpose with no problem. Retrieve the driver +files from the normal download area of the ESP Print Pro software +at <ulink + noescape="1" url="http://www.easysw.com/software.html">http://www.easysw.com/software.html</ulink>. +You need to locate the link labelled <quote>SAMBA</quote> among the +<guilabel>Download Printer Drivers for ESP Print Pro 4.x</guilabel> +area and download the package. Once installed, you can prepare any +driver by simply highlighting the printer in the Printer Manager GUI +and select <guilabel>Export Driver...</guilabel> from the menu. Of +course you need to have prepared Samba beforehand to handle the +driver files; i.e., setup the <smbconfsection>[print$]</smbconfsection> +share, and so on. The ESP Print Pro package includes the CUPS driver files +as well as a (licensed) set of Adobe drivers for the Windows 95/98/Me +client family. +</para> +</sect2> + +<sect2> +<title>Caveats to be Considered</title> + + +<para> +<indexterm><primary>cupsaddsmb</primary></indexterm> +Once you have run the install script (and possibly manually +moved the <filename>cups.hlp</filename> file to +<filename>/usr/share/cups/drivers/</filename>), the driver is +ready to be put into Samba's <smbconfsection>[print$]</smbconfsection> share (which often maps to +<filename>/etc/samba/drivers/</filename> and contains a subdirectory +tree with <emphasis>WIN40</emphasis> and +<emphasis>W32X86</emphasis> branches). You do this by running +<command>cupsaddsmb</command> (see also <command>man cupsaddsmb</command> for +CUPS since release 1.1.16). +</para> + +<tip><para> +<indexterm><primary>Single Sign On</primary></indexterm> +You may need to put root into the smbpasswd file by running +<command>smbpasswd</command>; 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 +<emphasis>single sign on</emphasis> to a Windows Domain Controller. +</para></tip> + +<para> +Once the driver files are in the <smbconfsection>[print$]</smbconfsection> share +and are initialized, they are ready to be downloaded and installed by +the Windows NT/200x/XP clients. +</para> + +<note><para> +Win 9x/Me clients will not work with the CUPS PostScript driver. For +these you still need to use the <filename>ADOBE*.*</filename> +drivers as previously stated. +</para></note> + +<note> +<para> +It is not harmful if you still have the +<filename>ADOBE*.*</filename> driver files from previous +installations in the <filename>/usr/share/cups/drivers/</filename> +directory. The new <command>cupsaddsmb</command> (from 1.1.16) will +automatically prefer its own drivers if it finds both. +</para></note> + +<note><para> +<indexterm><primary>"Printers" folder</primary></indexterm> +Should your Windows clients have had the old <filename>ADOBE*.*</filename> +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 <quote>delete</quote> the printer, as 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 <guilabel>Printers</guilabel> folder (possibly via <guilabel>Start > Settings > Control Panel > Printers</guilabel>), +right-click on the folder background and select <guimenuitem>Server +Properties</guimenuitem>. When the new dialog opens, select the +<guilabel>Drivers</guilabel> tab. On the list select the driver you +want to delete and click the <guilabel>Delete</guilabel> +button. This will only work if there is not one single printer left +that uses that particular driver. You need to <quote>delete</quote> all printers +using this driver in the <guilabel>Printers</guilabel> folder first. You will need +Administrator privileges to do this. +</para></note> + +<note><para> +<indexterm><primary>rpcclient</primary><secondary>setdriver</secondary></indexterm> +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 <link linkend="printing"/>. Either change +a driver for an existing printer by running the <guilabel>Printer Properties</guilabel> +dialog, or use <command>rpcclient</command> with the +<command>setdriver</command> subcommand. +</para></note> +</sect2> + +<sect2> +<title>Windows CUPS PostScript Driver Versus Adobe Driver</title> + +<para> +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 the CUPS ones: +</para> + +<itemizedlist> +<listitem><para>No hassle with the Adobe EULA.</para></listitem> + +<listitem><para>No hassle with the question <quote>Where do I +get the ADOBE*.* driver files from?</quote></para></listitem> + +<listitem><para> +<indexterm><primary>PJL</primary></indexterm> +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 printfile starts with +<parameter><1B >%-12345X</parameter> or +<parameter><escape>%-12345X</parameter> instead +of <parameter>%!PS</parameter>). This leads to the +CUPS daemon auto-typing the incoming file as a print-ready file, +not initiating a pass through the <parameter>pstops</parameter> filter (to speak more +technically, it is not regarded as the generic MIME-type +<indexterm><primary>application/postscript</primary></indexterm> +<parameter>application/postscript</parameter>, but as +the more special MIME type +<indexterm><primary>application/cups.vnd-postscript</primary></indexterm> +<parameter>application/cups.vnd-postscript</parameter>), +which therefore also leads to the page accounting in +<parameter>/var/log/cups/page_log</parameter> not +receiving the exact number of pages; instead the dummy page number +of <quote>1</quote> is logged in a standard setup).</para></listitem> + +<listitem><para>The Adobe driver has more options to misconfigure the +PostScript generated by it (like setting it inadvertently to +<guilabel>Optimize for Speed</guilabel>, instead of +<guilabel>Optimize for Portability</guilabel>, which +could lead to CUPS being unable to process it).</para></listitem> + +<listitem><para>The CUPS PostScript driver output sent by Windows +clients to the CUPS server is guaranteed to auto-type +as the generic MIME type <parameter>application/postscript</parameter>, +thus passing through the CUPS <parameter>pstops</parameter> filter and logging the +correct number of pages in the <filename>page_log</filename> for +accounting and quota purposes.</para></listitem> + +<listitem><para>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 +<emphasis>banner pages</emphasis> (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).</para></listitem> + +<listitem><para>The CUPS PostScript driver supports the inclusion of +the new <parameter>*cupsJobTicket</parameter> comments at the +beginning of the PostScript file (which could be used in the future +for all sort of beneficial extensions on the CUPS side, but which will +not disturb any other applications as they will regard it as a comment +and simply ignore it).</para></listitem> + +<listitem><para>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).</para></listitem> +</itemizedlist> + +</sect2> + +<sect2> +<title>Run cupsaddsmb (Quiet Mode)</title> + + +<para> +<indexterm><primary>cupsaddsmb</primary></indexterm> +<indexterm><primary>point 'n' print</primary></indexterm> +The <command>cupsaddsmb</command> command copies the needed files into your +<smbconfsection>[print$]</smbconfsection> share. Additionally, the PPD +associated with this printer is copied from +<filename>/etc/cups/ppd/</filename> to +<smbconfsection>[print$]</smbconfsection>. 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 (<smbconfoption><name>security</name><value>user</value></smbconfoption>). +</para> + +<para> +Here is an example of a successfully run <command>cupsaddsmb</command> command: +</para> + +<para><screen> +&rootprompt;<userinput>cupsaddsmb -U root infotec_IS2027</userinput> +Password for root required to access localhost via Samba: <userinput>['secret']</userinput> +</screen></para> + +<para> +To share <emphasis>all</emphasis> printers and drivers, use the +<option>-a</option> parameter instead of a printer name. Since +<command>cupsaddsmb</command> <quote>exports</quote> the printer drivers to Samba, it should be +obvious that it only works for queues with a CUPS driver associated. +</para> +</sect2> + +<sect2> +<title>Run cupsaddsmb with Verbose Output</title> + + +<para> +<indexterm><primary>cupsaddsmb</primary></indexterm> +Probably you want to see what's going on. Use the +<option>-v</option> parameter to get a more verbose output. The +output below was edited for better readability: all <quote>\</quote> at the end of +a line indicate that I inserted an artificial line break plus some +indentation here: +</para> + +<warning><para> +You will see the root password for the Samba account printed on +screen. +</para></warning> + +<para> + +<indexterm><primary>rpcclient</primary><secondary>adddriver</secondary></indexterm> +<indexterm><primary>rpcclient</primary><secondary>setdriver</secondary></indexterm> + <screen> +&rootprompt;<userinput>cupsaddsmb -U root -v infotec_2105</userinput> +Password for root required to access localhost via &example.server.samba;: +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. + +</screen></para> + +<para> +If you look closely, you'll discover your root password was transferred +unencrypted over the wire, so beware! Also, if you look further, +you'll discover error messages like <?latex \linebreak ?>NT_STATUS_OBJECT_NAME_COLLISION in between. They occur, because the directories WIN40 and W32X86 already existed in the <smbconfsection>[print$]</smbconfsection> driver download share (from a previous driver installation). They are harmless here. +</para> +</sect2> + +<sect2> +<title>Understanding cupsaddsmb</title> + + +<para> +<indexterm><primary>cupsaddsmb</primary></indexterm> +What has happened? What did <command>cupsaddsmb</command> do? There are five stages of +the procedure: +</para> + +<orderedlist> + <listitem><para> + <indexterm><primary>IPP</primary></indexterm> + Call the CUPS server via IPP and request the +driver files and the PPD file for the named printer.</para></listitem> + +<listitem><para>Store the files temporarily in the local +TEMPDIR (as defined in +<filename>cupsd.conf</filename>).</para></listitem> + +<listitem><para>Connect via smbclient to the Samba server's + <smbconfsection>[print$]</smbconfsection> share and put the files into the + share's WIN40 (for Windows 9x/Me) and W32X86/ (for Windows NT/200x/XP) subdirectories.</para></listitem> + +<listitem><para> +<indexterm><primary>rpcclient</primary><secondary>adddriver</secondary></indexterm> + Connect via rpcclient to the Samba server and +execute the <command>adddriver</command> command with the correct +parameters.</para></listitem> + +<listitem><para> +<indexterm><primary>rpcclient</primary><secondary>setdriver</secondary></indexterm> + Connect via rpcclient to the Samba server a second +time and execute the <command>setdriver</command> command.</para></listitem> +</orderedlist> + +<note> +<para> +You can run the <command>cupsaddsmb</command> 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): +</para> + +<para><screen> +&rootprompt;<userinput>cupsaddsmb -H sambaserver -h cupsserver -v printer</userinput> +</screen></para> +</note> +</sect2> + +<sect2> +<title>How to Recognize If cupsaddsmb Completed Successfully</title> + +<para> +You <emphasis>must</emphasis> always check if the utility completed +successfully in all fields. You need as a minimum these three messages +among the output: +</para> + +<orderedlist> + +<listitem><para><emphasis>Printer Driver infotec_2105 successfully +installed.</emphasis> # (for the W32X86 == Windows NT/200x/XP +architecture).</para></listitem> + +<listitem><para><emphasis>Printer Driver infotec_2105 successfully +installed.</emphasis> # (for the WIN40 == Windows 9x/Me +architecture).</para></listitem> + +<listitem><para><emphasis>Successfully set [printerXPZ] to driver +[printerXYZ].</emphasis></para></listitem> +</orderedlist> + +<para> +These messages are probably not easily recognized in the general +output. If you run <command>cupsaddsmb</command> with the <option>-a</option> +parameter (which tries to prepare <emphasis>all</emphasis> active CUPS +printer drivers for download), you might miss if individual printers +drivers had problems installing properly. Here a redirection of the +output will help you analyze the results in retrospective. +</para> + +<note><para> +It is impossible to see any diagnostic output if you do not run +<command>cupsaddsmb</command> in verbose mode. Therefore, we strongly recommend to not +use the default quiet mode. It will hide any problems from you that +might occur. +</para></note> +</sect2> + +<sect2> +<title>cupsaddsmb with a Samba PDC</title> + + +<para> +<indexterm><primary>cupsaddsmb</primary></indexterm> +Can't get the standard <command>cupsaddsmb</command> command to run on a Samba PDC? +Are you asked for the password credential all over again and again and +the command just will not take off at all? Try one of these +variations: +</para> + +<para><screen> +&rootprompt;<userinput>cupsaddsmb -U &example.workgroup;\\root -v printername</userinput> +&rootprompt;<userinput>cupsaddsmb -H &example.pdc.samba; -U &example.workgroup;\\root -v printername</userinput> +&rootprompt;<userinput>cupsaddsmb -H &example.pdc.samba; -U &example.workgroup;\\root -h cups-server -v printername</userinput> +</screen></para> + +<para> +(Note the two backslashes: the first one is required to +<quote>escape</quote> the second one). +</para> +</sect2> + +<sect2> +<title>cupsaddsmb Flowchart</title> + +<para> +<indexterm><primary>cupsaddsmb</primary></indexterm> +<link linkend="small14"/> shows a chart about the procedures, commandflows and +dataflows of the <command>cupaddsmb</command> command. Note again: cupsaddsmb is +not intended to, and does not work with, raw queues! +</para> + +<para> + <image id="small14"><imagedescription>cupsaddsmb flowchart.</imagedescription> + <imagefile>14small</imagefile></image> +</para> +</sect2> + +<sect2> +<title>Installing the PostScript Driver on a Client</title> + +<para> +<indexterm><primary>point 'n' print</primary></indexterm> +After <command>cupsaddsmb</command> 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: +</para> + +<itemizedlist> + + +<listitem><para> +<indexterm><primary>"Printers" folder</primary></indexterm> +Open the <guilabel>Printers</guilabel> +share of Samba in Network Neighborhood.</para></listitem> + +<listitem><para>Right-click on the printer in +question.</para></listitem> + +<listitem><para>From the opening context-menu select +<guimenuitem>Install...</guimenuitem> or +<guimenuitem>Connect...</guimenuitem> (depending on the Windows version you +use).</para></listitem> +</itemizedlist> + +<para> +After a few seconds, there should be a new printer in your +client's <emphasis>local</emphasis> <guilabel>Printers</guilabel> folder. On Windows +XP it will follow a naming convention of <emphasis>PrinterName on +SambaServer</emphasis>. (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 +<filename>\\SambaServer\PrinterName</filename> entry in the +drop-down list of available printers. +</para> + +<para> +<indexterm><primary>PPD</primary></indexterm> +<command>cupsaddsmb</command> will only reliably work with CUPS version 1.1.15 or higher +and Samba from 2.2.4. 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: +</para> + +<para><screen> +&dosprompt;<userinput>net use lpt1: \\sambaserver\printershare /user:ntadmin</userinput> +</screen></para> + +<para> +should you desire to use the CUPS networked PostScript RIP +functions. (Note that user <quote>ntadmin</quote> needs to be a valid Samba user +with the required privileges to access the printershare.) This +sets up the printer connection in the traditional +<emphasis>LanMan</emphasis> way (not using MS-RPC). +</para> +</sect2> + +<sect2> +<title>Avoiding Critical PostScript Driver Settings on the Client</title> + +<para> +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: +</para> + +<itemizedlist> +<listitem><para>Avoid the PostScript Output Option: Optimize +for Speed setting. Use the Optimize for +Portability instead (Adobe PostScript +driver).</para></listitem> + +<listitem><para>Don't use the Page Independence: +NO setting. Instead, use Page Independence +YES (CUPS PostScript Driver).</para></listitem> + +<listitem><para>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).</para></listitem> + +<listitem><para>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).</para></listitem> + +<listitem><para>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).</para></listitem> + +<listitem><para>Say Yes to PostScript +Error Handler (Adobe).</para></listitem> +</itemizedlist> +</sect2> +</sect1> + +<sect1> +<title>Installing PostScript Driver Files Manually Using rpcclient</title> + +<para> +Of course, you can run all the commands that are embedded into the +cupsaddsmb convenience utility yourself, one by one, and hereby upload +and prepare the driver files for future client downloads. +</para> + +<orderedlist> +<listitem><para>Prepare Samba (A CUPS print queue with the name of the +printer should be there. We are providing the driver +now).</para></listitem> + +<listitem><para>Copy all files to + <smbconfsection>[print$]</smbconfsection>.</para></listitem> + +<listitem><para> +<indexterm><primary>rpcclient</primary><secondary>adddriver</secondary></indexterm> +Run <command>rpcclient adddriver</command> +(for each client architecture you want to support).</para></listitem> + +<listitem><para> +<indexterm><primary>rpcclient</primary><secondary>setdriver</secondary></indexterm> +Run <command>rpcclient +setdriver.</command></para></listitem> +</orderedlist> + +<para> +<indexterm><primary>rpcclient</primary><secondary>enumports</secondary></indexterm> +<indexterm><primary>rpcclient</primary><secondary>enumprinters</secondary></indexterm> +<indexterm><primary>rpcclient</primary><secondary>enumdrivers</secondary></indexterm> +<indexterm><primary>rpcclient</primary><secondary>setdriver</secondary></indexterm> +<indexterm><primary>rpcclient</primary><secondary>adddriver</secondary></indexterm> +We are going to do this now. First, read the man page on <parameter>rpcclient</parameter> +to get a first idea. Look at all the printing related +subcommands. <command>enumprinters</command>, +<command>enumdrivers</command>, <command>enumports</command>, +<command>adddriver</command>, <command>setdriver</command> are among +the most interesting ones. <parameter>rpcclient</parameter> 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. +</para> + +<sect2> +<title>A Check of the rpcclient man Page</title> + +<para> + First let's check the <parameter>rpcclient</parameter> man page. Here are +two relevant passages: +</para> + +<para> +<command>adddriver <arch> <config></command> Execute an +<command>AddPrinterDriver()</command> RPC to install the printer driver information on +the server. The driver files should already exist in the +directory returned by <command>getdriverdir</command>. Possible +values for <parameter>arch</parameter> are the same as those for the +<command>getdriverdir</command> command. The +<parameter>config</parameter> parameter is defined as follows: +</para> + +<para><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 +</screen></para> + +<para>Any empty fields should be enter as the string <quote>NULL</quote>. </para> + +<para>Samba does not need to support the concept of Print Monitors +since these only apply to local printers whose driver can make use of +a bi-directional link for communication. This field should be <quote>NULL</quote>. +On a remote NT print server, the Print Monitor for a driver must +already be installed prior to adding the driver or else the RPC will +fail. +</para> + +<para> +<command>setdriver <printername> <drivername></command> +Execute a <command>SetPrinter()</command> command to update the +printer driver associated with an installed printer. The printer +driver must already be correctly installed on the print server. +</para> + +<para>See also the <command>enumprinters</command> and <command>enumdrivers</command> commands for +obtaining a list of installed printers and drivers. +</para> + +</sect2> + +<sect2> +<title>Understanding the rpcclient man Page</title> + +<para> +The <emphasis>exact</emphasis> 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 <quote>\</quote>. Usually you would type the +command in one line without the linebreaks: +<indexterm><primary>rpcclient</primary><secondary>adddriver</secondary></indexterm> +</para> + +<para><screen> + adddriver "Architecture" \ + "LongPrinterName:DriverFile:DataFile:ConfigFile:HelpFile:\ + LanguageMonitorFile:DataType:ListOfFiles,Comma-separated" +</screen></para> + +<para> +What the man pages denote as a simple <parameter><config></parameter> +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 names the <quote>LongPrinterName</quote> in +reality should be called the <quote>Driver Name</quote>. You can name it +anything you want, as long as you use this name later in the +<command>rpcclient ... setdriver</command> command. For +practical reasons, many name the driver the same as the +printer. +</para> + +<para> +It isn't simple at all. I hear you asking: +<quote>How do I know which files are "Driver +File</quote>, <quote>Data File</quote>, <quote>Config File</quote>, <quote>Help File</quote> and <quote>Language +Monitor File" in each case?</quote> &smbmdash; 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 overhearing 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 <command>rpcclient</command> to see what it tells us and +try to understand the man page more clearly that we've read just +now. +</para> +</sect2> + +<sect2> +<title>Producing an Example by Querying a Windows Box</title> + +<para> + <indexterm><primary>rpcclient</primary><secondary>getdriver</secondary></indexterm> + <indexterm><primary>rpcclient</primary><secondary>getprinter</secondary></indexterm> +We could run <command>rpcclient</command> with a +<command>getdriver</command> or a <command>getprinter</command> +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: +</para> + +<para><screen> +&rootprompt;<userinput>rpcclient -U'user%secret' NT-SERVER -c 'getdriver printername 3'</userinput> +</screen></para> + +<para> +From the result it should become clear which is which. Here is an example from my installation: +</para> + +<para> +<indexterm><primary>rpcclient</primary><secondary>getdriver</secondary></indexterm> + <screen> +&rootprompt;<userinput>rpcclient -U'Danka%xxxx' W200xSERVER \ + -c'getdriver "DANKA InfoStream Virtual Printer" 3'</userinput> + 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: [] + +</screen></para> + +<para> +Some printer drivers list additional files under the label +<parameter>Dependentfiles</parameter> and these would go into the last field +<parameter>ListOfFiles,Comma-separated</parameter>. For the CUPS +PostScript drivers, we do not need any (nor would we for the Adobe +PostScript driver), therefore, the field will get a <quote>NULL</quote> entry. +</para> +</sect2> + +<sect2> +<title>Requirements for adddriver and setdriver to Succeed</title> + +<para> +>From the man page (and from the quoted output +of <command>cupsaddsmb</command> 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 <command>rpcclient</command> +<indexterm><primary>rpcclient</primary><secondary>adddriver</secondary></indexterm> +subcommands (<command>adddriver</command> and +<command>setdriver</command>) need to encounter the following +preconditions to complete successfully: +</para> +<itemizedlist> + +<listitem><para>You are connected as <smbconfoption><name>printer admin</name></smbconfoption> or root (this is <emphasis>not</emphasis> the <quote>Printer Operators</quote> group in +NT, but the <emphasis>printer admin</emphasis> group as defined in +the <smbconfsection>[global]</smbconfsection> section of +&smb.conf;).</para></listitem> + +<listitem><para>Copy all required driver files to +<filename>\\SAMBA\print$\w32x86</filename> and +<filename>\\SAMBA\print$\win40</filename> as appropriate. They +will end up in the <quote>0</quote> respective <quote>2</quote> subdirectories later. For now, +<emphasis>do not</emphasis> put them there, they'll be automatically +used by the <command>adddriver</command> subcommand. (If you use +<command>smbclient</command> to put the driver files into the share, note that you need +to escape the <quote>$</quote>: <command>smbclient //sambaserver/print\$ -U +root.</command>)</para></listitem> + +<listitem><para>The user you're connecting as must be able to write to +the <smbconfsection>[print$]</smbconfsection> share and create +subdirectories.</para></listitem> + +<listitem><para>The printer you are going to setup for the Windows +clients needs to be installed in CUPS already.</para></listitem> + +<listitem><para> + <indexterm><primary>rpcclient</primary><secondary>setdriver</secondary></indexterm> + <indexterm><primary>rpcclient</primary><secondary>enumprinters</secondary></indexterm> + The CUPS printer must be known to Samba, otherwise the +<command>setdriver</command> subcommand fails with an +NT_STATUS_UNSUCCESSFUL error. To check if the printer is known by +Samba, you may use the <command>enumprinters</command> subcommand to +<command>rpcclient</command>. 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.</para></listitem> +</itemizedlist> +</sect2> + +<sect2> +<title>Manual Driver Installation in 15 Steps</title> + +<para> +We are going to install a printer driver now by manually executing all +required commands. As 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. +</para> + +<procedure> + <title>Manual Driver Installation</title> + +<step> +<title>Install the printer on CUPS.</title> + +<para><screen> +&rootprompt;<userinput>lpadmin -p mysmbtstprn -v socket://10.160.51.131:9100 -E \ + -P canonIR85.ppd</userinput> +</screen></para> + +<para> +This installs a printer with the name <parameter>mysmbtstprn</parameter> +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. +</para> +</step> + +<step> +<title>(Optional) Check if the printer is recognized by Samba.</title> + +<para> +<indexterm><primary>rpcclient</primary><secondary>enumprinters</secondary></indexterm> +<screen> + &rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'enumprinters' localhost \ + | grep -C2 mysmbtstprn</userinput> +flags:[0x800000] +name:[\\kde-bitshop\mysmbtstprn] +description:[\\kde-bitshop\mysmbtstprn,,mysmbtstprn] +comment:[mysmbtstprn] +</screen></para> + +<para> +This should show the printer in the list. If not, stop and restart +the Samba daemon (smbd), or send a HUP signal: +<screen> +&rootprompt;<userinput>kill -HUP `pidof smbd`</userinput> +</screen>Check again. Troubleshoot and repeat until +successful. Note the <quote>empty</quote> field between the two commas in the +<quote>description</quote> line. The driver name would appear here if there was one already. You need to know root's Samba password (as set by the +<command>smbpasswd</command> command) for this step and most of the +following steps. Alternately, you can authenticate as one of the +users from the <quote>write list</quote> as defined in &smb.conf; for +<smbconfsection>[print$]</smbconfsection>. +</para> +</step> + +<step> +<title>(Optional) Check if Samba knows a driver for the printer.</title> + +<para> + <indexterm><primary>rpcclient</primary><secondary>getprinter</secondary></indexterm> + <indexterm><primary>rpcclient</primary><secondary>getdriver</secondary></indexterm> + <screen> +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2' localhost \ + | grep driver </userinput> +drivername:[] + +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2' localhost \ + | grep -C4 driv</userinput> +servername:[\\kde-bitshop] +printername:[\\kde-bitshop\mysmbtstprn] +sharename:[mysmbtstprn] +portname:[Samba Printer Port] +drivername:[] +comment:[mysmbtstprn] +location:[] +sepfile:[] +printprocessor:[winprint] + +&rootprompt;<userinput>rpcclient -U root%xxxx -c 'getdriver mysmbtstprn' localhost</userinput> + result was WERR_UNKNOWN_PRINTER_DRIVER + +</screen></para> + +<para> +None of the three commands shown above should show a driver. +This step was done for the purpose of demonstrating this condition. An +attempt to connect to the printer at this stage will prompt the +message along the lines of: <quote>The server does not have the required printer +driver installed.</quote> +</para> +</step> + +<step> +<title>Put all required driver files into Samba's +[print$].</title> + +<para><screen> +&rootprompt;<userinput>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'</userinput> +</screen></para> + +<para> +(This command should be entered in one long single +line. Line-breaks and the line-end indicated by <quote>\</quote> have been inserted +for readability reasons.) This step is <emphasis>required</emphasis> +for the next one to succeed. It makes the driver files physically +present in the <smbconfsection>[print$]</smbconfsection> share. However, clients +would still not be able to install them, because Samba does not yet +treat them as driver files. A client asking for the driver would still +be presented with a <quote>not installed here</quote> message. +</para> +</step> + +<step> +<title>Verify where the driver files are now.</title> + +<para><screen> +&rootprompt;<userinput>ls -l /etc/samba/drivers/W32X86/</userinput> +total 669 +drwxr-sr-x 2 root ntadmin 532 May 25 23:08 2 +drwxr-sr-x 2 root ntadmin 670 May 16 03:15 3 +-rwxr--r-- 1 root ntadmin 14234 May 25 23:21 cups.hlp +-rwxr--r-- 1 root ntadmin 278380 May 25 23:21 cupsdrvr.dll +-rwxr--r-- 1 root ntadmin 215848 May 25 23:21 cupsui.dll +-rwxr--r-- 1 root ntadmin 169458 May 25 23:21 mysmbtstprn.PPD +</screen></para> + +<para> +The driver files now are in the W32X86 architecture <quote>root</quote> of +<smbconfsection>[print$]</smbconfsection>. +</para> +</step> + +<step> +<title>Tell Samba that these are driver files (<command>adddriver</command>).</title> + +<para> +<indexterm><primary>rpcclient</primary><secondary>adddriver</secondary></indexterm> +<screen> +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c `adddriver "Windows NT x86" \ + "mydrivername:cupsdrvr.dll:mysmbtstprn.PPD: \ + cupsui.dll:cups.hlp:NULL:RAW:NULL" \ + localhost</userinput> +Printer Driver mydrivername successfully installed. +</screen></para> + +<para> +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 <quote>2</quote> 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. +</para> +</step> + +<step> +<title>Verify where the driver files are now.</title> + +<para><screen> +&rootprompt;<userinput>ls -l /etc/samba/drivers/W32X86/</userinput> +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 + +&rootprompt;<userinput>ls -l /etc/samba/drivers/W32X86/2</userinput> +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 +</screen></para> + +<para> +Notice how step 6 also moved the driver files to the appropriate +subdirectory. Compare this with the situation after step 5. +</para> +</step> + +<step> +<title>(Optional) Verify if Samba now recognizes the driver.</title> + +<para> +<indexterm><primary>rpcclient</primary><secondary>enumdrivers</secondary></indexterm> +<screen> +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'enumdrivers 3' \ + localhost | grep -B2 -A5 mydrivername</userinput> +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] +</screen></para> + +<para> +Remember, this command greps for the name you chose for the +driver in step 6. This command must succeed before you can proceed. +</para> +</step> + +<step> +<para>Tell Samba which printer should use these driver files (<command>setdriver</command>).</para> + + +<para> +<indexterm><primary>rpcclient</primary><secondary>setdriver</secondary></indexterm> +<screen> +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'setdriver mysmbtstprn mydrivername' \ + localhost</userinput> +Successfully set mysmbtstprn to driver mydrivername +</screen></para> + +<para> +Since you can bind any printername (print queue) to any driver, this +is a convenient way to setup 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: +<command>enumdrivers</command> must find the driver and +<command>enumprinters</command> must find the printer. +</para> +</step> + +<step> + <title>(Optional) Verify if Samba has recognized this association.</title> + +<para> +<indexterm><primary>rpcclient</primary><secondary>getprinter</secondary></indexterm> +<indexterm><primary>rpcclient</primary><secondary>getdriver</secondary></indexterm> +<indexterm><primary>rpcclient</primary><secondary>enumprinters</secondary></indexterm> +<screen> +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2' localhost \ + | grep driver</userinput> +drivername:[mydrivername] + +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'getprinter mysmbtstprn 2' localhost \ + | grep -C4 driv</userinput> +servername:[\\kde-bitshop] +printername:[\\kde-bitshop\mysmbtstprn] +sharename:[mysmbtstprn] +portname:[Done] +drivername:[mydrivername] +comment:[mysmbtstprn] +location:[] +sepfile:[] +printprocessor:[winprint] + +&rootprompt;<userinput>rpcclient -U root%xxxx -c 'getdriver mysmbtstprn' localhost</userinput> +[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] + +&rootprompt;<userinput>rpcclient -Uroot%xxxx -c 'enumprinters' localhost \ + | grep mysmbtstprn</userinput> + name:[\\kde-bitshop\mysmbtstprn] + description:[\\kde-bitshop\mysmbtstprn,mydrivername,mysmbtstprn] + comment:[mysmbtstprn] + +</screen></para> + +<para> +<indexterm><primary>rpcclient</primary><secondary>enumprinters</secondary></indexterm> +Compare these results with the ones from steps 2 and 3. Every one of these commands show the driver is installed. Even +the <command>enumprinters</command> command now lists the driver +on the <quote>description</quote> line. +</para> +</step> + +<step> +<title>(Optional) Tickle the driver into a correct +device mode.</title> + +<para> +<indexterm><primary>"Printers" folder</primary></indexterm> +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. An alternate way is to +open the <guilabel>Printers (and Faxes)</guilabel> folder, right-click on the printer in +question and select <guilabel>Connect</guilabel> or <guilabel>Install</guilabel>. As a result, a new printer +should have appeared in your client's local <guilabel>Printers (and Faxes)</guilabel> +folder, named something like <guilabel>printersharename on Sambahostname</guilabel>. +</para> + +<para> +It is important that you execute this step as a Samba printer admin +(as defined in &smb.conf;). Here is another method +to do this on Windows XP. It uses a command line, which you may type +into the <quote>DOS box</quote> (type root's smbpassword when prompted): +</para> + +<para><screen> +&dosprompt;<userinput>runas /netonly /user:root "rundll32 printui.dll,PrintUIEntry \ + /in /n \\sambaserver\mysmbtstprn"</userinput> +</screen></para> + +<para> +Change any printer setting once (like changing <emphasis><guilabel>portrait</guilabel> to + <guilabel>landscape</guilabel></emphasis>), click on <guibutton>Apply</guibutton>; change the setting +back. +</para> +</step> + +<step> +<title>Install the printer on a client +(Point'n'Print).</title> + + +<para> +<indexterm significance="preferred"><primary>point 'n' print</primary></indexterm> + <screen> +&dosprompt;<userinput>rundll32 printui.dll,PrintUIEntry /in /n "\\sambaserver\mysmbtstprn"</userinput> +</screen></para> + +<para> +If it does not work it could be a permission problem with the +<smbconfsection>[print$]</smbconfsection> share. +</para> +</step> + +<step> +<title>(Optional) Print a test page.</title> + +<para><screen> +&dosprompt;<userinput>rundll32 printui.dll,PrintUIEntry /p /n "\\sambaserver\mysmbtstprn"</userinput> +</screen></para> + +<para> +Then hit [TAB] five times, [ENTER] twice, [TAB] once and [ENTER] again +and march to the printer. +</para> +</step> + +<step> +<title>(Recommended) Study the test page.</title> + +<para> +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" &smbmdash; why not just throw it away! +</para> +</step> + +<step> +<title>(Obligatory) Enjoy. Jump. Celebrate your +success.</title> + +<para><screen> +&rootprompt;<userinput>echo "Cheeeeerioooooo! Success..." >> /var/log/samba/log.smbd</userinput> +</screen></para> +</step> +</procedure> +</sect2> + +<sect2> +<title>Troubleshooting Revisited</title> + +<para> +The setdriver command will fail, if in Samba's mind the queue is not +already there. You had promising messages about the: +</para> + +<para><screen> + Printer Driver ABC successfully installed. +</screen></para> + +<para> +after the <command>adddriver</command> parts of the procedure? But you are also seeing +a disappointing message like this one? +</para> + +<para><computeroutput> + result was NT_STATUS_UNSUCCESSFUL +</computeroutput></para> + +<para> +<indexterm><primary>lpstat</primary></indexterm> +It is not good enough that you +can see the queue in CUPS, using +the <command>lpstat -p ir85wm</command> command. A +bug in most recent versions of Samba prevents the proper update of +the queuelist. 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 <command>setdriver</command> command successfully, check if Samba <quote>sees</quote> +the printer: +</para> + +<para> +<indexterm><primary>rpcclient</primary><secondary>enumprinters</secondary></indexterm> + <screen> +&rootprompt;<userinput>rpcclient transmeta -N -U'root%xxxx' -c 'enumprinters 0'|grep ir85wm</userinput> + printername:[ir85wm] +</screen></para> + +<para> +An alternate command could be this: +</para> + +<para> +<indexterm><primary>rpcclient</primary><secondary>getprinter</secondary></indexterm> + <screen> +&rootprompt;<userinput>rpcclient transmeta -N -U'root%secret' -c 'getprinter ir85wm' </userinput> + cmd = getprinter ir85wm + flags:[0x800000] + name:[\\transmeta\ir85wm] + description:[\\transmeta\ir85wm,ir85wm,DPD] + comment:[CUPS PostScript-Treiber for Windows NT/200x/XP] +</screen></para> + +<para> +By the way, you can use these commands, plus a few more, of course, +to install drivers on remote Windows NT print servers too! +</para> +</sect2> +</sect1> + +<sect1> +<title>The Printing <filename>*.tdb</filename> Files</title> + +<para> +<indexterm><primary>TDB</primary></indexterm> +<indexterm><primary>connections.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>printing.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>share_info.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>ntdrivers.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>unexpected.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>brlock.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>locking.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>ntforms.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>messages.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>ntprinters.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>sessionid.tdb</primary><seealso>TDB</seealso></indexterm> +<indexterm><primary>secrets.tdb</primary><seealso>TDB</seealso></indexterm> +Some mystery is associated with the series of files with a +tdb suffix appearing in every Samba installation. They are +<filename>connections.tdb</filename>, +<filename>printing.tdb</filename>, +<filename>share_info.tdb</filename>, +<filename>ntdrivers.tdb</filename>, +<filename>unexpected.tdb</filename>, +<filename>brlock.tdb</filename>, +<filename>locking.tdb</filename>, +<filename>ntforms.tdb</filename>, +<filename>messages.tdb</filename> , +<filename>ntprinters.tdb</filename>, +<filename>sessionid.tdb</filename> and +<filename>secrets.tdb</filename>. What is their purpose? +</para> + +<sect2> +<title>Trivial Database Files</title> + +<para> +<indexterm><primary>TDB</primary></indexterm> +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 <filename>*.tdb</filename> files. (TDB = Trivial Data +Base). These are often located in <filename>/var/lib/samba/</filename> +or <filename>/var/lock/samba/</filename>. The printing related files +are <filename>ntprinters.tdb</filename>, +<filename>printing.tdb</filename>,<filename>ntforms.tdb</filename> and +<filename>ntdrivers.tdb</filename>. +</para> +</sect2> + +<sect2> +<title>Binary Format</title> + +<para> +<filename>*.tdb</filename> files are not human readable. They are +written in a binary format. <quote>Why not ASCII?</quote>, you may ask. <quote>After all, +ASCII configuration files are a good and proven tradition on UNIX.</quote> +The reason for this design decision by the Samba team is mainly +performance. Samba needs to be fast; it runs a separate +<command>smbd</command> process for each client connection, in some +environments many thousands of them. Some of these smbds might need to +write-access the same <filename>*.tdb</filename> file <emphasis>at the +same time</emphasis>. The file format of Samba's +<filename>*.tdb</filename> files allows for this provision. Many smbd +processes may write to the same <filename>*.tdb</filename> file at the +same time. This wouldn't be possible with pure ASCII files. +</para> +</sect2> + +<sect2> +<title>Losing <filename>*.tdb</filename> Files</title> + +<para> +It is very important that all <filename>*.tdb</filename> files remain +consistent over all write and read accesses. However, it may happen +that these files <emphasis>do</emphasis> get corrupted. (A +<command>kill -9 `pidof smbd'</command> while a write access is in +progress could do the damage as well as a power interruption, +etc.). In cases of trouble, a deletion of the old printing-related +<filename>*.tdb</filename> files may be the only option. After that you need to +re-create all print-related setup or you have made a +backup of the <filename>*.tdb</filename> files in time. +</para> +</sect2> + +<sect2> +<title>Using <command>tdbbackup</command></title> + + +<para> +<indexterm><primary>TDB</primary><secondary>backing up</secondary><see>tdbbackup</see></indexterm> +<indexterm><primary>tdbbackup</primary></indexterm> +Samba ships with a little utility that helps the root user of your +system to backup your <filename>*.tdb</filename> files. If you run it +with no argument, it prints a usage message: +</para> + +<para><screen> +&rootprompt;<userinput>tdbbackup</userinput> + Usage: tdbbackup [options] <fname...> + + Version:3.0a + -h this help message + -s suffix set the backup suffix + -v verify mode (restore if corrupt) + +</screen></para> + +<para> +Here is how I backed up my <filename>printing.tdb</filename> file: +</para> + +<para><screen> +&rootprompt;<userinput>ls</userinput> +. 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 + +&rootprompt;<userinput>tdbbackup -s .bak printing.tdb</userinput> + printing.tdb : 135 records + +&rootprompt;<userinput>ls -l printing.tdb*</userinput> + -rw------- 1 root root 40960 May 2 03:44 printing.tdb + -rw------- 1 root root 40960 May 2 03:44 printing.tdb.bak + +</screen></para> +</sect2> +</sect1> + +<sect1> +<title>CUPS Print Drivers from Linuxprinting.org</title> + + +<para> +<indexterm><primary>Linuxprinting.org</primary></indexterm> +CUPS ships with good support for HP LaserJet-type printers. You can +install the generic driver as follows: +</para> + + +<para> +<indexterm><primary>lpadmin</primary></indexterm> + <screen> +&rootprompt;<userinput>lpadmin -p laserjet4plus -v parallel:/dev/lp0 -E -m laserjet.ppd</userinput> +</screen></para> + +<para> +The <option>-m</option> switch will retrieve the +<filename>laserjet.ppd</filename> from the standard repository for +not-yet-installed-PPDs, which CUPS typically stores in +<filename>/usr/share/cups/model</filename>. Alternately, you may use +<option>-P /path/to/your.ppd</option>. +</para> + +<para> +The generic <filename>laserjet.ppd,</filename> however, does not support every special option +for every LaserJet-compatible model. It constitutes a sort of <quote>least common +denominator</quote> 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 <ulink +noescape="1" url="http://www.linuxprinting.org/printer_list.cgi">http://www.linuxprinting.org/printer_list.cgi</ulink>. +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 <command>foomatic-rip</command> utility. +</para> + +<note><para> +<indexterm><primary>foomatic-rip</primary></indexterm> +The former <command>cupsomatic</command> concept is now being replaced by the new +successor, a much +more powerful <command>foomatic-rip</command>. +<command>cupsomatic</command> is no longer maintained. Here is the new URL +to the Foomatic-3.0 database: <ulink +noescape="1" url="http://www.linuxprinting.org/driver_list.cgi">http://www.linuxprinting.org/driver_list.cgi</ulink>. +If you upgrade to <command>foomatic-rip</command>, 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 <command>cupsomatic</command>. The new-style +PPDs are 100% compliant to 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! +</para></note> + +<sect2> +<title>foomatic-rip and Foomatic Explained</title> + + +<para> +<indexterm significance="preferred"><primary>foomatic</primary></indexterm> +<indexterm significance="preferred"><primary>foomatic-rip</primary></indexterm> +Nowadays, most Linux distributions rely on the utilities of Linuxprinting.org +to create their printing-related software (which, by the way, works on all +UNIXes and on Mac OS X or Darwin, too). It is not known as well as it +should be, that it also has 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. +</para> + +<para> +Recently, Foomatic has achieved the astonishing milestone of <ulink +url="http://www.linuxprinting.org/printer_list.cgi?make=Anyone">1000 +listed</ulink> 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 <ulink +url="http://www.linuxprinting.org/foomatic.html">Foomatic</ulink> +database. Currently there are <ulink +url="http://www.linuxprinting.org/driver_list.cgi">245 drivers</ulink> +in the database. Many drivers support various models, and many models +may be driven by different drivers &smbmdash; its your choice! +</para> + +<sect3> +<title>690 <quote>Perfect</quote> Printers</title> + +<para> +At present, there are 690 devices dubbed as working perfectly, 181 +mostly, 96 partially, 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 &smbmdash; 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. +</para> +</sect3> + +<sect3> +<title>How the Printing HOWTO Started It All</title> + +<para> +A few years ago <ulink url="http://www2.picante.com:81/~gtaylor/">Grant Taylor</ulink> +started it all. The roots of today's Linuxprinting.org are in the +first <ulink url="http://www.linuxprinting.org/foomatic2.9/howto/">Linux Printing +HOWTO</ulink> 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 +<quote>applying a structured deposition of distinct patterns of ink or toner +particles on paper substrates</quote>, 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. +</para> +</sect3> + +<sect3> +<title>Foomatic's Strange Name</title> + + +<para> +<indexterm><primary>foomatic</primary></indexterm> +<quote>Why the funny name?</quote> 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 (<parameter>pstoraster</parameter>, derived from +Ghostscript). On the other hand, CUPS provided brilliant support for +<emphasis>controlling</emphasis> all printer options through +standardized and well-defined PPD files (PostScript Printers +Description files). Plus, CUPS was designed to be easily extensible. +</para> + +<para> +Taylor already had in his database a respectable compilation +of facts about many more printers and the Ghostscript <quote>drivers</quote> +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: +</para> + +<itemizedlist> +<listitem><para>It made all current and future Ghostscript filter +developments available for CUPS.</para></listitem> + +<listitem><para>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).</para></listitem> + +<listitem><para>It gave all the advanced CUPS options (Web interface, +GUI driver configurations) to users wanting (or needing) to use +Ghostscript filters.</para></listitem> +</itemizedlist> +</sect3> + +<sect3> +<title>cupsomatic, pdqomatic, lpdomatic, directomatic</title> + + +<para> +<indexterm><primary>cupsomatic</primary></indexterm> +<indexterm><primary>CUPS-PPD</primary></indexterm> +<indexterm><primary>PPD</primary><secondary>CUPS</secondary><see>CUPS-PPD</see></indexterm> +CUPS worked through a quickly-hacked up filter script named <ulink +url="http://www.linuxprinting.org/download.cgi?filename=cupsomatic&show=0">cupsomatic.</ulink> +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 <ulink +url="http://www.linuxprinting.org/download.cgi?filename=lpdomatic&show=0">PDQ-O-Matic</ulink> +(for PDQ) and <ulink +url="http://www.linuxprinting.org/download.cgi?filename=lpdomatic&show=0">LPD-O-Matic</ulink> +(for &smbmdash; you guessed it &smbmdash; LPD); the configuration here didn't use PPDs +but other spooler-specific files. +</para> + +<para> +From late summer of that year, <ulink url="http://www.linuxprinting.org/till/">Till Kamppeter</ulink> +started to put work into the database. Kamppeter had been newly employed by +<ulink url="http://www.mandrakesoft.com/">MandrakeSoft</ulink> to +convert its printing system over to CUPS, after they had seen his +<ulink url="http://www.fltk.org/">FLTK</ulink>-based <ulink +url="http://cups.sourceforge.net/xpp/">XPP</ulink> (a GUI frontend 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 +<ulink url="http://ppr.sourceforge.net/">PPR</ulink> (via ppromatic), +<ulink url="http://sourceforge.net/projects/lpr/">GNUlpr</ulink> and +<ulink url="http://www.lprng.org/">LPRng</ulink> (both via an extended +lpdomatic) and spoolerless printing (<ulink +url="http://www.linuxprinting.org/download.cgi?filename=directomatic&show=0">directomatic</ulink>). +</para> + +<para> +So, to answer your question: <quote>Foomatic</quote> is the general name for all +the overlapping code and data behind the <quote>*omatic</quote> scripts. +Foomatic, up to versions 2.0.x, required (ugly) Perl data structures +attached to Linuxprinting.org PPDs for CUPS. It had a different +<quote>*omatic</quote> script for every spooler, as well as different printer +configuration files. +</para> +</sect3> + +<sect3> +<title>The <emphasis>Grand Unification</emphasis> Achieved</title> + + +<para> +<indexterm><primary>foomatic-rip</primary></indexterm> +This has all changed in Foomatic versions 2.9 (beta) and released as +<quote>stable</quote> 3.0. It has now achieved the convergence of all *omatic +scripts and is called the <ulink +url="http://www.linuxprinting.org/foomatic2.9/download.cgi?filename=foomatic-rip&show=0">foomatic-rip.</ulink> +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 &smbmdash; paper sizes and trays are easier to configure. +</para> + +<para> +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 <ulink +url="http://www.linuxprinting.org/download/foomatic/foomatic-db-engine-3.0.0beta1.tar.gz">foomatic-db-engine!</ulink> +Individual users just need to generate a single new PPD specific to +their model by <ulink +url="http://www.linuxprinting.org/kpfeifle/LinuxKongress2002/Tutorial/II.Foomatic-User/II.tutorial-handout-foomatic-user.html">following +the steps</ulink> outlined in the Foomatic tutorial or in this chapter. This new development is truly amazing. +</para> + +<para> +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). +</para> +</sect3> + +<sect3> +<title>Driver Development Outside</title> + +<para> +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. +</para> + +<para> +Speaking of the different driver development groups, most of +the work is currently done in three projects. These are: +</para> + +<itemizedlist> +<listitem><para><ulink +url="http://www-124.ibm.com/developerworks/oss/linux/projects/omni/">Omni</ulink> +&smbmdash; a free software project by IBM that tries to convert their 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.</para></listitem> + +<listitem><para><ulink url="http://hpinkjet.sf.net/">HPIJS</ulink> &smbmdash; +a free software project by HP to provide the support for their own +range of models (very mature, printing in most cases is perfect and +provides true photo quality). This currently supports 369 +models.</para></listitem> + +<listitem><para><ulink +url="http://gimp-print.sf.net/">Gimp-Print</ulink> &smbmdash; 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.</para></listitem> +</itemizedlist> +</sect3> + +<sect3> +<title>Forums, Downloads, Tutorials, Howtos &smbmdash; also for Mac OS X and Commercial UNIX</title> + +<para> +Linuxprinting.org today is the one-stop shop to download printer +drivers. Look for printer information and <ulink +url="http://www.linuxprinting.org//kpfeifle/LinuxKongress2002/Tutorial/">tutorials</ulink> +or solve printing problems in its popular <ulink +url="http://www.linuxprinting.org/newsportal/">forums.</ulink> This forum +it's not just for GNU/Linux users, but admins of <ulink +url="http://www.linuxprinting.org/macosx/">commercial UNIX +systems</ulink> are also going there, and the relatively new <ulink +url="http://www.linuxprinting.org/newsportal/thread.php3?name=linuxprinting.macosx.general">Mac +OS X forum</ulink> has turned out to be one of the most frequented +forums after only a few weeks. +</para> + +<para> +Linuxprinting.org and the Foomatic driver wrappers around Ghostscript +are now a standard toolchain 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 (who works at Mandrake), many +additional contributions came from engineers with SuSE, RedHat, +Connectiva, Debian, and others. Vendor-neutrality is an important goal +of the Foomatic project. +</para> + +<note><para> +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. +</para></note> +</sect3> + +<sect3> +<title>Foomatic Database-Generated PPDs</title> + +<para> +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 modelled to the +Adobe specification of PostScript Printer Descriptions (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 a HP Photosmart, or +what-have-you. The main trick is one little additional line, not +envisaged by the PPD specification, starting with the <parameter>*cupsFilter</parameter> +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 printjob into a raster format ready for the +target device. This usage of PPDs to describe the options of non-PS +printers was the invention of the CUPS developers. The rest is easy. +GUI tools (like KDE's marvelous <ulink +url="http://printing.kde.org/overview/kprinter.phtml">kprinter,</ulink> +or the GNOME <ulink +url="http://gtklp.sourceforge.net/">gtklp,</ulink> 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. +</para> +</sect3> +</sect2> + +<sect2> +<title>foomatic-rip and Foomatic-PPD Download and Installation</title> + +<para> +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 +<command>foomatic-rip</command> utility. Going directly to +Linuxprinting.org ensures that you get the latest driver/PPD files): +</para> + +<itemizedlist> +<listitem><para>Open your browser at the Linuxprinting.org printer list<ulink url="http://www.linuxprinting.org/printer_list.cgi">page.</ulink> +</para></listitem> + +<listitem><para>Check the complete list of printers in the +<ulink url="http://www.linuxprinting.org/printer_list.cgi?make=Anyone">database.</ulink>. +</para></listitem> + +<listitem><para>Select your model and click on the link. +</para></listitem> + +<listitem><para>You'll arrive at a page listing all drivers working with this +model (for all printers, there will always be <emphasis>one</emphasis> +recommended driver. Try this one first). +</para></listitem> + +<listitem><para>In our case (HP LaserJet 4 Plus), we'll arrive at the default driver for the +<ulink url="http://www.linuxprinting.org/show_printer.cgi?recnum=HP-LaserJet_4_Plus">HP-LaserJet 4 Plus.</ulink> +</para></listitem> + +<listitem><para>The recommended driver is ljet4.</para></listitem> + +<listitem><para>Several links are provided here. You should visit them all if you +are not familiar with the Linuxprinting.org database. +</para></listitem> + +<listitem><para>There is a link to the database page for the +<ulink url="http://www.linuxprinting.org/show_driver.cgi?driver=ljet4">ljet4.</ulink> +On the driver's page, you'll find important and detailed information +about how to use that driver within the various available +spoolers.</para></listitem> + +<listitem><para>Another link may lead you to the homepage of the +driver author or the driver.</para></listitem> + +<listitem><para>Important links are the ones that provide hints with +setup instructions for <ulink noescape="1" url="http://www.linuxprinting.org/cups-doc.html">CUPS</ulink>, +<ulink url="http://www.linuxprinting.org/pdq-doc.html">PDQ</ulink>, +<ulink url="http://www.linuxprinting.org/lpd-doc.html">LPD, LPRng and GNUlpr</ulink>) +as well as <ulink url="http://www.linuxprinting.org/ppr-doc.html">PPR</ulink> +or <quote>spooler-less</quote> <ulink url="http://www.linuxprinting.org/direct-doc.html">printing.</ulink> +</para></listitem> + +<listitem><para>You can view the PPD in your browser through this link: +<ulink noescape="1" url="http://www.linuxprinting.org/ppd-o-matic.cgi?driver=ljet4&printer=HP-LaserJet_4_Plus&show=1">http://www.linuxprinting.org/ppd-o-matic.cgi?driver=ljet4&printer=HP-LaserJet_4_Plus&show=1</ulink> +</para></listitem> <listitem><para>Most importantly, you can also generate and download +the <ulink url="http://www.linuxprinting.org/ppd-o-matic.cgi?driver=ljet4&printer=HP-LaserJet_4_Plus&show=0">PPD.</ulink> +</para></listitem> + +<listitem><para>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.</para></listitem> + +<listitem><para>If you ended up on the drivers +<ulink url="http://www.linuxprinting.org/show_driver.cgi?driver=ljet4">page</ulink> +you can choose to use the <quote>PPD-O-Matic</quote> online PPD generator +program.</para></listitem> + +<listitem><para>Select the exact model and check either <guilabel>Download</guilabel> or +<guilabel>Display PPD file</guilabel> and click <guilabel>Generate PPD file</guilabel>.</para></listitem> + +<listitem><para>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 <guimenuitem>Save +as...</guimenuitem> in your browser's menu. (It is best to use the <guilabel>Download</guilabel> option +directly from the Web page).</para></listitem> + +<listitem><para>Another interesting part on each driver page is +the <guimenuitem>Show execution details</guimenuitem> 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 +<quote>learn Ghostscript by doing</quote>. It is also an excellent cheat sheet +for all experienced users who need to re-construct a good command line +for that damn printing script, but can't remember the exact +syntax. </para></listitem> + +<listitem><para>Some time during your visit to Linuxprinting.org, save +the PPD to a suitable place on your harddisk, say +<filename>/path/to/my-printer.ppd</filename> (if you prefer to install +your printers with the help of the CUPS Web interface, save the PPD to +the <filename>/usr/share/cups/model/</filename> path and restart +cupsd).</para></listitem> + +<listitem><para>Then install the printer with a suitable command line, +like this: +</para> + +<para><screen> +&rootprompt;<userinput>lpadmin -p laserjet4plus -v parallel:/dev/lp0 -E \ + -P path/to/my-printer.ppd</userinput> +</screen></para></listitem> + +<listitem><para>For all the new-style <quote>Foomatic-PPDs</quote> +from Linuxprinting.org, you also need a special CUPS filter named +foomatic-rip. +</para></listitem> + +<listitem><para>The foomatic-rip Perlscript itself also makes some +interesting <ulink url="http://www.linuxprinting.org/foomatic2.9/download.cgi?filename=foomatic-rip&show=1">reading</ulink> +because it is well documented by Kamppeter's inline comments (even +non-Perl hackers will learn quite a bit about printing by reading +it).</para></listitem> + +<listitem><para>Save foomatic-rip either directly in +<filename>/usr/lib/cups/filter/foomatic-rip</filename> 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 +<guimenuitem>Save as...</guimenuitem> menu item in your browser.</para></listitem> + +<listitem><para>If you save foomatic-rip in your $PATH, create a symlink: +<screen> +&rootprompt;<userinput>cd /usr/lib/cups/filter/ ; ln -s `which foomatic-rip'</userinput> +</screen> +</para> + +<para> +CUPS will discover this new available filter at startup after restarting +cupsd.</para></listitem> +</itemizedlist> + +<para> +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 jobfile. foomatic-rip is able to read and act upon +these and uses some specially encoded Foomatic comments +embedded in the jobfile. 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: +</para> + +<itemizedlist> + +<listitem><para>A <quote>foomatic+something</quote> PPD &smbmdash; but this is not enough +to print with CUPS (it is only <emphasis>one</emphasis> important +component).</para></listitem> + +<listitem><para>The <parameter>foomatic-rip</parameter> filter script (Perl) in +<filename>/usr/lib/cups/filters/</filename>.</para></listitem> + +<listitem><para>Perl to make foomatic-rip run.</para></listitem> + +<listitem><para>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.</para></listitem> + +<listitem><para>Ghostscript <emphasis>must</emphasis> (depending on +the driver/model) contain support for a certain device representing +the selected driver for your model (as shown by <command>gs + -h</command>).</para></listitem> + +<listitem><para>foomatic-rip needs a new version of PPDs (PPD versions +produced for cupsomatic do not work with +foomatic-rip).</para></listitem> +</itemizedlist> +</sect2> +</sect1> + +<sect1> +<title>Page Accounting with CUPS</title> + + +<para> +<indexterm><primary>CUPS</primary><secondary>Page Accounting</secondary></indexterm> +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 <emphasis>or</emphasis> unfiltered) and hand it over to this +printing subsystem. +</para> + +<para> +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 span any time +period you want. +</para> + +<sect2> +<title>Setting Up Quotas</title> + +<para> +<indexterm><primary>CUPS</primary><secondary>quotas</secondary></indexterm> +This is an example command of how root would set a print quota in CUPS, +assuming an existing printer named <quote>quotaprinter</quote>: +</para> + + +<para> +<indexterm><primary>lpadmin</primary></indexterm> + <screen> +&rootprompt;<userinput>lpadmin -p quotaprinter -o job-quota-period=604800 \ + -o job-k-limit=1024 -o job-page-limit=100</userinput> +</screen></para> + +<para> +This would limit every single user to print 100 pages or 1024 KB of +data (whichever comes first) within the last 604,800 seconds ( = 1 +week). +</para> +</sect2> + +<sect2> +<title>Correct and Incorrect Accounting</title> + +<para> +For CUPS to count correctly, the printfile needs to pass the CUPS +pstops filter, otherwise it uses a dummy count of <quote>one</quote>. 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 <quote>raw</quote> (i.e., leaving them untouched, not +filtering them), will be counted as one-pagers too! +</para> + +<para> +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 has a driver +<ulink url="http://www.linuxprinting.org/printer_list.cgi">list.</ulink> +</para> +</sect2> + +<sect2> +<title>Adobe and CUPS PostScript Drivers for Windows Clients</title> + +<para> +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 <command>pstops</command> 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 <command>pstops</command> and go directly +to the <command>pstoraster</command> stage). +</para> + +<para> +From CUPS 1.1.16 onward, you can use the CUPS PostScript Driver for +Windows <?latex \linebreak ?>NT/200x/XP clients (which is tagged in the download area of +<filename>http://www.cups.org/</filename> as the <filename>cups-samba-1.1.16.tar.gz</filename> +package). It does <emphasis>not</emphasis> work for Windows 9x/ME clients, but it guarantees: +</para> + +<itemizedlist> + +<listitem><para> <indexterm><primary>PJL</primary></indexterm> To not write a PJL-header.</para></listitem> + +<listitem><para>To still read and support all PJL-options named in the +driver PPD with its own means.</para></listitem> + +<listitem><para>That the file will pass through the <command>pstops</command> filter +on the CUPS/Samba server.</para></listitem> + +<listitem><para>To page-count correctly the print file.</para></listitem> +</itemizedlist> + +<para> +You can read more about the setup of this combination in the man page +for <command>cupsaddsmb</command> (which is only present with CUPS installed, and only +current from CUPS 1.1.16). +</para> +</sect2> + +<sect2> +<title>The page_log File Syntax</title> + +<para> +<indexterm><primary>page_log</primary></indexterm> +These are the items CUPS logs in the <filename>page_log</filename> for every +page of a job: +</para> + +<itemizedlist> +<listitem><para>Printer name</para></listitem> + +<listitem><para>User name</para></listitem> + +<listitem><para>Job ID</para></listitem> + +<listitem><para>Time of printing</para></listitem> + +<listitem><para>The page number</para></listitem> + +<listitem><para>The number of copies</para></listitem> + +<listitem><para>A billing information string (optional)</para></listitem> + +<listitem><para>The host that sent the job (included since version 1.1.19)</para></listitem> +</itemizedlist> + +<para> +Here is an extract of my CUPS server's <filename>page_log</filename> file to illustrate the +format and included items: +</para> + +<para><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 +</screen></para> + +<para> +This was job ID <parameter>401</parameter>, printed on <parameter>tec_IS2027</parameter> +by user <parameter>kurt</parameter>, a 64-page job printed in three copies and billed to +<parameter>#marketing</parameter>, sent from IP address <constant>10.160.50.13.</constant> + The next job had ID <parameter>402</parameter>, was sent by user <parameter>boss</parameter> +from IP address <constant>10.160.51.33</constant>, printed from one page 440 copies and +is set to be billed to <parameter>finance-dep</parameter>. +</para> +</sect2> + +<sect2> +<title>Possible Shortcomings</title> + +<para> +What flaws or shortcomings are there with this quota system? +</para> + +<itemizedlist> +<listitem><para>The ones named above (wrongly logged job in case of +printer hardware failure, and so on).</para></listitem> + +<listitem><para>In reality, CUPS counts the job pages that are being +processed in <emphasis>software</emphasis> (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 a thousand and the job is aborted by the printer, the page count will +still show the figure of a thousand for that job.</para></listitem> + +<listitem><para>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.</para></listitem> + +<listitem><para>No means to read out the current balance or the +<quote>used-up</quote> number of current quota.</para></listitem> + +<listitem><para>A user having used up 99 sheets of a 100 quota will +still be able to send and print a thousand sheet job.</para></listitem> + +<listitem><para>A user being denied a job because of a filled-up quota +does not get a meaningful error message from CUPS other than +<quote>client-error-not-possible</quote>.</para></listitem> +</itemizedlist> +</sect2> + +<sect2> +<title>Future Developments</title> + +<para> +This is the best system currently available, and there are huge +improvements under development for CUPS 1.2: +</para> + +<itemizedlist> +<listitem><para>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).</para></listitem> + +<listitem><para>Quotas will be handled more flexibly.</para></listitem> + +<listitem><para>Probably there will be support for users to inquire +about their accounts in advance.</para></listitem> + +<listitem><para>Probably there will be support for some other tools +around this topic.</para></listitem> +</itemizedlist> +</sect2> + +<!-- FIXME +<sect2> +<title>Other Accounting Tools</title> + +<para> +PrintAnalyzer, pyKota, printbill, LogReport. +</para> +</sect2> +--> +</sect1> + +<sect1> +<title>Additional Material</title> + +<para> +A printer queue with <emphasis>no</emphasis> PPD associated to it is a +<quote>raw</quote> printer and all files will go directly there as received by the +spooler. The exceptions are file types <parameter>application/octet-stream</parameter> +that need passthrough feature enabled. <quote>Raw</quote> 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 <quote>device URI</quote> notation: <filename>lpd://, socket://, +smb://, ipp://, http://, parallel:/, serial:/, usb:/</filename>, and so on). +</para> + +<para> +cupsomatic/Foomatic are <emphasis>not</emphasis> 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. <parameter>cupsomatic</parameter> is only a vehicle to execute a +Ghostscript commandline at that stage in the CUPS filtering chain, +where normally the native CUPS <parameter>pstoraster</parameter> filter would kick +in. cupsomatic bypasses pstoraster, kidnaps the printfile from CUPS +away and redirects it to go through Ghostscript. CUPS accepts this, +because the associated cupsomatic/foomatic-PPD specifies: + +<filterline> + *cupsFilter: "application/vnd.cups-postscript 0 cupsomatic" +</filterline> + +This line persuades CUPS to hand the file to cupsomatic, once it has +successfully converted it to the MIME type +<parameter>application/vnd.cups-postscript</parameter>. This conversion will not happen for +Jobs arriving from Windows that are auto-typed +<parameter>application/octet-stream</parameter>, with the according changes in +<filename>/etc/cups/mime.types</filename> in place. +</para> + +<para> +CUPS is widely configurable and flexible, even regarding its filtering +mechanism. Another workaround in some situations would be to have in +<filename>/etc/cups/mime.types</filename> entries as follows: + +<filterline> + application/postscript application/vnd.cups-raw 0 - + application/vnd.cups-postscript application/vnd.cups-raw 0 - +</filterline> + +This would prevent all PostScript files from being filtered (rather, +they will through the virtual <emphasis>nullfilter</emphasis> +denoted with <quote>-</quote>). This could only be useful for PS printers. If you +want to print PS code on non-PS printers (provided they support ASCII +text printing), an entry as follows could be useful: + +<filterline> + */* application/vnd.cups-raw 0 - +</filterline> + +and would effectively send <emphasis>all</emphasis> files to the +backend without further processing. +</para> + +<para> +You could have the following entry: + +<filterline> +application/vnd.cups-postscript application/vnd.cups-raw 0 \ + my_PJL_stripping_filter +</filterline> + +You will need to write a <parameter>my_PJL_stripping_filter</parameter> +(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 +<filename>/usr/lib/cups/filters/</filename> and is called by CUPS +if it encounters a MIME type <parameter>application/vnd.cups-postscript</parameter>. +</para> + +<para> +CUPS can handle <parameter>-o job-hold-until=indefinite</parameter>. +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). +</para> +</sect1> + +<sect1> +<title>Auto-Deletion or Preservation of CUPS Spool Files</title> + +<para> +Samba print files pass through two spool directories. One is the +incoming directory managed by Samba, (set in the +<smbconfoption><name>path</name><value>/var/spool/samba</value></smbconfoption> +directive in the <smbconfsection>[printers]</smbconfsection> section of +&smb.conf;). The other is the spool directory of +your UNIX print subsystem. For CUPS it is normally +<filename>/var/spool/cups/</filename>, as set by the <filename>cupsd.conf</filename> +directive <filename>RequestRoot /var/spool/cups</filename>. +</para> + +<sect2> +<title>CUPS Configuration Settings Explained</title> + +<para> +Some important parameter settings in the CUPS configuration file +<filename>cupsd.conf</filename> are: +</para> + +<variablelist> + +<varlistentry><term>PreserveJobHistory Yes</term> +<listitem><para> +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 do a +similar job as the old-fashioned BSD-LPD control files). This is set +to <quote>Yes</quote> as a default. +</para></listitem></varlistentry> + +<varlistentry><term>PreserveJobFiles Yes</term> +<listitem><para> +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 <quote>No</quote> as the CUPS +default. +</para></listitem></varlistentry> + +<varlistentry><term><emphasis><quote>MaxJobs 500</quote></emphasis></term> +<listitem><para> +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. +</para></listitem></varlistentry> +</variablelist> + +<para> +(There are also additional settings for <parameter>MaxJobsPerUser</parameter> and +<parameter>MaxJobsPerPrinter</parameter>...) +</para> +</sect2> + +<sect2> +<title>Pre-Conditions</title> + +<para> +For everything to work as announced, you need to have three +things: +</para> + +<itemizedlist> +<listitem><para>A Samba-smbd that is compiled against <filename>libcups</filename> (check +on Linux by running <userinput>ldd `which smbd'</userinput>).</para></listitem> + +<listitem><para>A Samba-&smb.conf; setting of + <smbconfoption><name>printing</name><value>cups</value></smbconfoption>.</para></listitem> + +<listitem><para>Another Samba-&smb.conf; setting of + <smbconfoption><name>printcap</name><value>cups</value></smbconfoption>.</para></listitem> +</itemizedlist> + +<note><para> +In this case, all other manually set printing-related commands (like +<smbconfoption><name>print command</name></smbconfoption>, +<smbconfoption><name>lpq command</name></smbconfoption>, +<smbconfoption><name>lprm command</name></smbconfoption>, +<smbconfoption><name>lppause command</name></smbconfoption> or +<smbconfoption><name>lpresume command</name></smbconfoption>) are ignored and they should normally have no +influence whatsoever on your printing. +</para></note> +</sect2> + +<sect2> +<title>Manual Configuration</title> + +<para> +If you want to do things manually, replace the <smbconfoption><name>printing</name><value>cups</value></smbconfoption> +by <smbconfoption><name>printing</name><value>bsd</value></smbconfoption>. Then your manually set commands may work +(I haven't tested this), and a <smbconfoption><name>print command</name><value>lp -d %P %s; rm %s"</value></smbconfoption> +may do what you need. +</para> +</sect2> +</sect1> + +<sect1> +<title>Printing from CUPS to Windows Attached Printers</title> + +<para> +>From time to time the question arises, how can you print +<emphasis>to</emphasis> a Windows attached printer +<emphasis>from</emphasis> 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 +<emphasis>backends</emphasis> to talk to printers and other +servers. To talk to Windows shared printers, you need to use the +<filename>smb</filename> (surprise, surprise!) backend. Check if this +is in the CUPS backend directory. This usually resides in +<filename>/usr/lib/cups/backend/</filename>. You need to find an <filename>smb</filename> +file there. It should be a symlink to <filename>smbspool</filename> +and the file must exist and be executable: +</para> + +<para><screen> +&rootprompt;<userinput>ls -l /usr/lib/cups/backend/</userinput> +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 + +&rootprompt;<userinput>ls -l `which smbspool`</userinput> +-rwxr-xr-x 1 root root 563245 Dec 28 14:49 /usr/bin/smbspool +</screen></para> + +<para> +If this symlink does not exist, create it: +</para> + +<para><screen> +&rootprompt;<userinput>ln -s `which smbspool` /usr/lib/cups/backend/smb</userinput> +</screen></para> + +<para> +<command>smbspool</command> has been 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 <replaceable>winprinter</replaceable> 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. +</para> + +<para> +To install a printer with the <parameter>smb</parameter> backend on CUPS, use this command: +</para> + +<para><screen> +&rootprompt;<userinput>lpadmin -p winprinter -v smb://WINDOWSNETBIOSNAME/printersharename \ + -P /path/to/PPD</userinput> +</screen></para> + +<para> +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 +<filename>smb://</filename> device-URI like this: +</para> + +<itemizedlist> + <listitem><para><filename>smb://WORKGROUP/WINDOWSNETBIOSNAME/printersharename</filename></para></listitem> + <listitem><para><filename>smb://username:password@WORKGROUP/WINDOWSNETBIOSNAME/printersharename</filename></para></listitem> + <listitem><para><filename>smb://username:password@WINDOWSNETBIOSNAME/printersharename</filename></para></listitem> +</itemizedlist> + +<para> +Note that the device-URI will be visible in the process list of the +Samba server (e.g., when someone uses the <command>ps -aux</command> +command on Linux), even if the username and passwords are sanitized +before they get written into the log files. So 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. + +</para> +</sect1> + +<sect1> +<title>More CUPS-Filtering Chains</title> + +<para> +The following diagrams reveal how CUPS handles print jobs. +</para> + +<image id="cups1"><imagefile>cups1</imagefile><imagedescription>Filtering chain 1.</imagedescription></image> + +<image id="cups2"><imagefile>cups2</imagefile><imagedescription>Filtering chain with cupsomatic</imagedescription></image> + +</sect1> + +<sect1> + <title>Common Errors</title> + + <sect2> + <title>Windows 9x/ME Client Can't Install Driver</title> + + <para>For Windows 9x/ME, clients require the printer names to be eight +characters (or <quote>8 plus 3 chars suffix</quote>) max; otherwise, the driver files +will not get transferred when you want to download them from +Samba.</para> + + </sect2> + + <sect2> + <title><quote>cupsaddsmb</quote> Keeps Asking for Root Password in Never-ending Loop</title> + + <para>Have you <smbconfoption><name>security</name><value>user</value></smbconfoption>? Have +you used <command>smbpasswd</command> to give root a Samba account? +You can do two things: open another terminal and execute +<command>smbpasswd -a root</command> 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).</para> + + </sect2> + + <sect2> + <title><quote>cupsaddsmb</quote> Errors</title> + + <para> + The use of <quote>cupsaddsmb</quote> gives <quote>No PPD file for printer...</quote> Message While PPD File Is Present. + What might the problem be? + </para> + + <para>Have you enabled printer sharing on CUPS? This means: +Do you have a <parameter><Location +/printers>....</Location></parameter> section in CUPS +server's <filename>cupsd.conf</filename> that does not deny access to +the host you run <quote>cupsaddsmb</quote> from? It <emphasis>could</emphasis> be +an issue if you use cupsaddsmb remotely, or if you use it with a +<option>-h</option> parameter: <userinput>cupsaddsmb -H + sambaserver -h cupsserver -v printername</userinput>. +</para> +<para>Is your +<parameter>TempDir</parameter> directive in +<filename>cupsd.conf</filename> +set to a valid value and is it writeable? +</para> + + </sect2> + + <sect2> + <title>Client Can't Connect to Samba Printer</title> + <para>Use <command>smbstatus</command> to check which user +you are from Samba's point of view. Do you have the privileges to +write into the <smbconfsection>[print$]</smbconfsection> +share?</para> + + </sect2> + + <sect2> + <title>New Account Reconnection from Windows 200x/XP Troubles</title> + +<para>Once you are connected as the wrong user (for +example, as <constant>nobody</constant>, which often occurs if you have +<smbconfoption><name>map to guest</name><value>bad user</value></smbconfoption>), Windows Explorer will not accept an +attempt to connect again as a different user. There will not be any byte +transfered on the wire to Samba, but still you'll see a stupid error +message that makes you think Samba has denied access. Use +<command>smbstatus</command> to check for active connections. Kill the +PIDs. You still can't re-connect and you get the dreaded +<computeroutput>You can't connect with a second account from the same +machine</computeroutput> message, as soon as you are trying. And you +do not see any single byte arriving at Samba (see logs; use <quote>ethereal</quote>) +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 <emphasis>first</emphasis> +do <userinput>net use z: \\&example.server.samba;\print$ /user:root</userinput>. Check +with <command>smbstatus</command> that you are connected under a +different account. Now open the <guilabel>Printers</guilabel> folder (on the Samba server +in the <guilabel>Network Neighborhood</guilabel>), right-click on the +printer in question and select +<guibutton>Connect...</guibutton></para></sect2> + +<sect2> +<title>Avoid Being Connected to the Samba Server as the Wrong User</title> + +<para>You see per <command>smbstatus</command> that you are +connected as user nobody; while you want to be root or +printeradmin. This is probably due to +<smbconfoption><name>map to guest</name><value>bad user</value></smbconfoption>, which silently connects you under the guest account +when you gave (maybe by accident) an incorrect username. Remove +<smbconfoption><name>map to guest</name></smbconfoption>, if you want to prevent +this.</para></sect2> + +<sect2> +<title>Upgrading to CUPS Drivers from Adobe Drivers</title> + +<para> +This information came from a mailinglist posting regarding problems experienced when +upgrading from Adobe drivers to CUPS drivers on Microsoft Windows NT/200x/XP Clients. +</para> + +<para>First delete all old Adobe-using printers. Then +delete all old Adobe drivers. (On Windows 200x/XP, right-click in +the background of <guilabel>Printers</guilabel> folder, select <guimenuitem>Server Properties...</guimenuitem>, select +tab <guilabel>Drivers</guilabel> and delete here).</para></sect2> + +<sect2><title>Can't Use <quote>cupsaddsmb</quote> on Samba Server Which Is a PDC</title> +<para>Do you use the <quote>naked</quote> root user name? Try to do it +this way: <userinput>cupsaddsmb -U <replaceable>DOMAINNAME</replaceable>\\root -v +<replaceable>printername</replaceable></userinput>> (note the two backslashes: the first one is +required to <quote>escape</quote> the second one).</para></sect2> + +<sect2><title>Deleted Windows 200x Printer Driver Is Still Shown</title> +<para>Deleting a printer on the client will not delete the +driver too (to verify, right-click on the white background of the +<guilabel>Printers</guilabel> folder, select <guimenuitem>Server Properties</guimenuitem> and click on the +<guilabel>Drivers</guilabel> 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.</para></sect2> + +<sect2><title>Windows 200x/XP "Local Security Policies"</title> +<para>Local Security Policies may not +allow the installation of unsigned drivers. <quote>Local Security Policies</quote> +may not allow the installation of printer drivers at +all.</para></sect2> + +<sect2><title>Administrator Cannot Install Printers for All Local Users</title> +<para>Windows XP handles SMB printers on a <quote>per-user</quote> basis. +This means every user needs to install the printer himself. To have a +printer available for everybody, you might want to use the built-in +IPP client capabilities of WinXP. Add a printer with the print path of +<parameter>http://cupsserver:631/printers/printername</parameter>. +We're still looking into this one. Maybe a logon script could +automatically install printers for all +users.</para></sect2> + +<sect2><title>Print Change Notify Functions on NT-clients</title> +<para>For print change, notify functions on NT++ clients. +These need to run the <command>Server</command> service first (renamed to +<command>File & Print Sharing for MS Networks</command> in +XP).</para></sect2> + +<sect2> +<title>WinXP-SP1</title> + +<para>WinXP-SP1 introduced a Point and Print Restriction Policy (this restriction does not apply to +<quote>Administrator</quote> or <quote>Power User</quote> groups of users). In Group Policy +Object Editor, go to <guimenu>User Configuration -> Administrative Templates -> + Control Panel -> Printers</guimenu>. The policy is automatically set to +<constant>Enabled</constant> and the <constant>Users can only Point +and Print to machines in their Forest</constant> . You probably need +to change it to <constant>Disabled</constant> or <constant>Users can +only Point and Print to these servers</constant> to make +driver downloads from Samba possible. +</para> +</sect2> + +<sect2> +<title>Print Options for All Users Can't Be Set on Windows 200x/XP</title> + +<para>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 <emphasis>seems</emphasis> to set everything. All +three dialogs <emphasis>look</emphasis> 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: +</para> + +<orderedlist numeration="upperalpha"> + +<listitem><para>The first wrong way: + +<orderedlist> +<listitem><para>Open the <guilabel>Printers</guilabel> +folder.</para></listitem> + +<listitem><para>Right-click on the printer +(<guilabel>remoteprinter on cupshost</guilabel>) and +select in context menu <guimenuitem>Printing +Preferences...</guimenuitem></para></listitem> + +<listitem><para>Look at this dialog closely and remember what it looks +like.</para></listitem> +</orderedlist> +</para> +</listitem> + +<listitem><para>The second wrong way: + +<orderedlist> +<listitem><para>Open the <guilabel>Printers</guilabel> +folder.</para></listitem> + +<listitem><para>Right-click on the printer (<guilabel>remoteprinter on +cupshost</guilabel>) and select the context menu +<guimenuitem>Properties</guimenuitem>.</para></listitem> + +<listitem><para>Click on the <guilabel>General</guilabel> +tab.</para></listitem> + +<listitem><para>Click on the button <guibutton>Printing +Preferences...</guibutton></para></listitem> + +<listitem><para>A new dialog opens. Keep this dialog open and go back +to the parent dialog.</para></listitem> +</orderedlist> +</para> +</listitem> + +<listitem><para>The third, and the correct way: + +<orderedlist> + +<listitem><para>Open the <guilabel>Printers</guilabel> +folder.</para></listitem> + +<listitem><para>Click on the <guilabel>Advanced</guilabel> +tab. (If everything is <quote>grayed out,</quote> then you are not logged +in as a user with enough privileges).</para></listitem> + +<listitem><para>Click on the <guibutton>Printing +Defaults...</guibutton> button.</para></listitem> + +<listitem><para>On any of the two new tabs, click on the +<guibutton>Advanced...</guibutton> +button.</para></listitem> + +<listitem><para>A new dialog opens. Compare this one to the other +identical looking one from <quote>B.5</quote> or A.3".</para></listitem> +</orderedlist> +</para> +</listitem> +</orderedlist> + +<para> +Do you see any difference? I don't either. However, only the last +one, which you arrived at with steps <quote>C.1.-6.</quote>, 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 <emphasis>as +Administrator</emphasis> (<smbconfoption><name>printer admin</name></smbconfoption> in +&smb.conf;) <emphasis>before</emphasis> a client +downloads the driver (the clients can later set their own +<emphasis>per-user defaults</emphasis> by following the +procedures <emphasis>A</emphasis> or <emphasis>B</emphasis> +above).</para></sect2> + +<sect2><title>Most Common Blunders in Driver Settings on Windows Clients</title> +<para>Don't use <parameter>Optimize for +Speed</parameter>, but use <parameter>Optimize for +Portability</parameter> instead (Adobe PS Driver). Don't use +<parameter>Page Independence: No</parameter>: always +settle with <parameter>Page Independence: +Yes</parameter> (Microsoft PS Driver and CUPS PS Driver for +Windows NT/200x/XP). If there are problems with fonts, use +<parameter>Download as Softfont into +printer</parameter> (Adobe PS Driver). For +<guilabel>TrueType Download Options</guilabel> +choose <constant>Outline</constant>. Use PostScript +Level 2, if you are having trouble with a non-PS printer and if +there is a choice.</para></sect2> + +<sect2><title><command>cupsaddsmb</command> Does Not Work with Newly Installed Printer</title> +<para>Symptom: The last command of +<command>cupsaddsmb</command> does not complete successfully: +<command>cmd = setdriver printername printername</command> 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 i n <command>rpcclient +hostname -c `enumprinters'</command>? Restart smbd (or send a +<command>kill -HUP</command> to all processes listed by +<command>smbstatus</command> and try +again.</para></sect2> + +<sect2> +<title>Permissions on <filename>/var/spool/samba/</filename> Get Reset After Each Reboot</title> +<para>Have you ever by accident set the CUPS spool directory to +the same location? (<parameter>RequestRoot /var/spool/samba/</parameter> in <filename>cupsd.conf</filename> or +the other way round: <filename>/var/spool/cups/</filename> is set as +<smbconfoption><name>path</name></smbconfoption>> in the <smbconfsection>[printers]</smbconfsection> +section). These <parameter>must</parameter> be different. Set +<!--FIXME--> +<parameter>RequestRoot /var/spool/cups/</parameter> in +<filename>cupsd.conf</filename> and <smbconfoption><name>path</name><value> +/var/spool/samba</value></smbconfoption> in the <smbconfsection>[printers]</smbconfsection> +section of &smb.conf;. Otherwise cupsd will +sanitize permissions to its spool directory with each restart and +printing will not work reliably.</para></sect2> + +<sect2> +<title>Print Queue Called <quote>lp</quote> Mis-handles Print Jobs</title> + +<para> +In this case a print queue called <quote>lp</quote> intermittently swallows jobs and +spits out completely different ones from what was sent. +</para> + +<para>It is a bad idea to name any printer <quote>lp</quote>. 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-balancing the jobs across them in a round-robin fashion. Chances +are high that someone else has a printer named <quote>lp</quote> too. You may +receive his jobs and send your own to his device unwittingly. To have +tight control over the printer names, set <parameter>BrowseShortNames +No</parameter>. It will present any printer as <replaceable>printername@cupshost</replaceable> +and then gives you better control over what may happen in a large +networked environment.</para></sect2> + +<sect2><title>Location of Adobe PostScript Driver Files for <quote>cupsaddsmb</quote></title> +<para>Use <command>smbclient</command> to connect to any +Windows box with a shared PostScript printer: <command>smbclient +//windowsbox/print\$ -U guest</command>. You can navigate to the +<filename>W32X86/2</filename> subdir to <command>mget ADOBE*</command> +and other files or to <filename>WIN40/0</filename> to do the same. +Another option is to download the <filename>*.exe</filename> packaged +files from the Adobe Web site.</para></sect2> + +</sect1> + +<sect1> +<title>Overview of the CUPS Printing Processes</title> + +<para>A complete overview of the CUPS printing processes can be found in <link linkend="a_small"/>.</para> + +<image id="a_small"><imagedescription>CUPS printing overview.</imagedescription> + <imagefile>a_small</imagefile> +</image> +</sect1> + +</chapter> + + + + + + + + + + + + |