tdebase/doc/tdeprint/cupsoptions.docbook

<chapter id="cupsoptions-presently-outside-kcontrol">
<title>&CUPS; options presently not available through &kcontrol;</title>

<para>This chapter gives you some hints about further configuration
possibilities which may not be available through the &tdeprint; &GUI;
interface to &CUPS;.</para>

<sect1>
<title>Overview of provided features</title>

<para>All of the most often used features and functions &CUPS; provides
are supported in &tdeprint;.</para>

<itemizedlist>
<listitem>
<para>Printer management is supported: add, remove, modify, configure,
test, disable, enable ...</para>
</listitem>
<listitem>
<para>Job management is supported: cancel, hold, release, move to
different printer</para>
</listitem>
<listitem>
<para>Print options: for full control as provided by &CUPS;.</para>
</listitem>
</itemizedlist>

</sect1>

<sect1 id="where-to-find-further-chupshelp">
<title>Where to find help when using &CUPS;</title>

<para>A lot of information about the inner workings of &CUPS; is
available through the web interface, which &CUPS; will always
support. It works with any browser (yes, even text-based ones). Just go
to <ulink url="http://localhost:631/">http://localhost:631/</ulink> for
a start. There you find a link to locally available &CUPS; documentation
in <acronym>HTML</acronym> and <acronym>PDF</acronym> if you are new to
&CUPS;.</para>

<para>&CUPS; is accessible through other means than &tdeprint;:
commandline and browser are two native &CUPS; interfaces. The many
commandline utilities add up to the most complete control you have on
&CUPS;. The web interface is only a subset of all available
configuration or control options. </para>

<para>This is also true for &tdeprint;. Generally, as &CUPS; develops,
most new features will first be implemented through the commandline. Be
sure to check the latest versions of the man pages for &CUPS; to stay
up-to-date with new features after you install a new version.</para>

<tip>
<para>Depending on your update method for &CUPS;, your active
configuration file might not have been re-placed by a new one; thus your
new, more capable &CUPS;-daemon might not have been told by the old
configuration file about the new features to use.</para>
</tip>

<para>A complete list of available files and man pages should always be
in the &CUPS; Software Administrator Manual (<ulink
url="http://localhost:631/sam.html#FILES">http://localhost:631/sam.html#FILES</ulink>.
In the &konqueror; &URL;/location field, type
<userinput>man:/lpadmin</userinput> and
<userinput>man:/cupsd.conf</userinput> to find out about the most
important command and configuration file. You knew already about
&konqueror;'s nice abilities to show you the traditional &UNIX; man
pages, didn't you? Read this.  From there you find more interesting
hints and links to other man pages and documentation.</para>

<sect2>
<title>How to find &CUPS; related man pages</title>

<para>Here is a way to find out which &CUPS; related man pages there
are on your system: </para>

<screen><prompt>kurt@transmeta:~ ></prompt> <userinput><command>apropos</command> <parameter>cups</parameter></userinput>
<computeroutput>
cups-calibrate (8)- ESP Printer Calibration Tool
lpstat (1)        - print cups status information
cups-lpd (8)      - receive print jobs + report printer status to lpd clients
classes.conf (5)  - class configuration file for cups
backend (1)       - cups backend transmission interfaces
filter (1)        - cups file conversion filter interfaces
cups-polld (8)    - cups printer polling daemon
mime.types (5)    - mime type description file for cups
cupsd (8)         - common unix printing system daemon
lpadmin (8)       - configure cups printers and classes
cupsd.conf (5)    - server configuration file for cups
mime.convs (5)    - mime type conversion file for cups
printers.conf (5) - printer configuration file for cups
mime.convs (5)    - mime type conversion file for cups
cups-polld (8)    - cups printer polling daemon
lpstat (1)        - print cups status information
backend (1)       - cups backend transmission interfaces
mime.types (5)    - mime type description file for cups
cupsd (8)         - common unix printing system daemon
lpadmin (8)       - configure cups printers and classes
printers.conf (5) - printer configuration file for cups
cupsd.conf (5)    - server configuration file for cups
filter (1)        - cups file conversion filter interfaces
</computeroutput></screen>
</sect2>
</sect1>

<sect1 id="tips-and-tricks-for-cups">
<title>Outside &tdeprint;: Hints &amp; Tips Tricks with &CUPS; on the
Commandline</title>

<para>Here are a few examples of options that are presently only
available if you use the commandline. </para>

<sect2>
<title>Allowing or denying printer access for certain users</title>

<para>When installing (or modifying) a printer through the command line,
you can either deny or allow the usage of that printer to certain
users:</para>

<screen><userinput><command>lpadmin</command> <option>-p</option><parameter>HeidelbergDigimaster9110</parameter> <option>-v</option> <parameter>lpd:/10.160.16.99/mqueue</parameter> <option>-u</option> <parameter>allow:kurt,sylvi,hansjoerg</parameter> <option>-E</option> <option>-P</option> <parameter>/home/kurt/PPDs/DVHV.ppd</parameter></userinput></screen>

<para>will allow the usage of this (believe me: very nice and also very
professional) printer to only the three mentioned users and at the same
time deny it to all others. If another user wants to print on the
DigiMaster via this &CUPS; server, he will receive an error message
along the lines <errortype>client-error-not-possible</errortype>.</para>

<screen><userinput><command>lpadmin</command> <option>-p</option> <parameter>HeidelbergDigimaster9110</parameter> <option>-v</option> <parameter>lpd:/10.160.16.99/mqueue</parameter> <option>-u</option> <parameter>deny:tackat,boss,waba</parameter> <option>-E</option> <option>-P</option> <parameter>/home/kurt/PPDs/DVHV.ppd</parameter></userinput></screen>

<para>will deny the usage of this same printer to the three mentioned
users and at the same time allow it to all others. If
<quote>denied</quote> user wants to print on the DigiMaster via this
&CUPS; server, he will receive an error message along the lines
<errortype>client-error-not-possible</errortype>.</para>

<note>
<para>Only one of the two options may be used at one time; at present
there is no support to have a similar option in a per-group based
way. This will be implemented in the future.</para>
</note>

</sect2>
<sect2>
<title>Imposing Quotas for certain printers</title>

<para>Sometimes you want to impose quotas for certain printers.  With
quotas you can set upper limits for the number of pages or the amount of
data to be printed over a certain period to a certain printer.</para>

<para>Quotas can be set with the <option>-o</option> option when
installing a printer with the <command>lpadmin</command> command, or
afterwards for an already existing printer. Following are some
guidelines (which are missing at the time of writing in the, official
&CUPS; documentation):</para>

<itemizedlist>
<listitem>
<para>With &CUPS; you may have pagecount- and filesize-based quotas for
individual printers.</para>
</listitem>

<listitem>
<para>Quotas are calculated for each user individually (so a single set
of limits applies to all users for the printer concerned).</para>
</listitem>

<listitem>
<para>Quotas include banner pages (if those are used).</para>
</listitem>

<listitem>
<para>This means: you can limit every user to 20 pages per day on an
expensive printer, but you cannot limit every user except <systemitem
class="username">Kurt</systemitem> or <systemitem
class="username">root</systemitem>.</para>
</listitem>

<listitem>
<para>There are <option>job-k-limit</option>,
<option>job-page-limit</option>, and <option>job-quota-period</option>
options to give when setting up a printer.</para>
</listitem>

<listitem>
<para><option>job-quota-period</option> sets a time interval for quota
computing (intervals are determined in seconds; so a day is
60x60x24=86.400, a week is 60x60x24x7=604,800, and a month is
60x60x24x30=2.592.000 seconds.)</para>
</listitem>

<listitem>
<para>For quotas to be enforced, the time-period
<emphasis>plus</emphasis> at least one job-limit must be set to
non-zero.</para>
</listitem>

<listitem>
<para>The default value of 0 for <option>job-k-limit</option> specifies
that there is no limit.</para>
</listitem>

<listitem>
<para>The default value of 0 for <option>job-page-limit</option>
specifies that there is no limit.</para>
</listitem>

<listitem>
<para>The default value of 0 for <option>job-quota-period</option>
specifies that the limits apply to all jobs that have been printed by a
user that are still known to the system.</para>
</listitem>
</itemizedlist>

<sect3>
<title>Working Examples:</title>

<para>Working, as both, time-period <emphasis>plus</emphasis> one or
both job-limits are defined</para>

<screen><userinput><command>lpadmin</command> <option>-p</option> <parameter>danka_infotec_4850</parameter> <option>-o</option> <parameter>job-quota-period=604800</parameter> <option>-o</option> <parameter>job-k-limit=1024</parameter></userinput></screen>

<para>This sets a limit of a file size of 1 MB (in total) for each user
of existing printer <systemitem
class="resource">danka_infotec_4850</systemitem> during one week.</para>

<screen><userinput><command>lpadmin</command> <option>p</option> <parameter>danka_infotec_4105</parameter> <option>-o</option> <parameter>job-quota-period=604800</parameter> <option>-o</option> <parameter>job-page-limit=100</parameter></userinput></screen>

<para>This sets a limit of 100 pages (in total) for each user of
existing printer <systemitem
class="resource">danka_infotec_4105</systemitem> during one week.</para>

<screen><userinput><command>lpadmin</command> <option>-p</option> <parameter>danka_infotec_P450</parameter> <option>-o</option> <parameter>job-quota-period=604800</parameter> <option>-o</option> <parameter>job-k-limit=1024</parameter> <option>-o</option> <parameter>job-page-limit=100</parameter></userinput></screen>

<para>This sets a combined limit of 1 MB (in total) and 100 pages (in
total) for each user of existing printer <systemitem
class="resource">danka_infotec_P450</systemitem> during one
week. Whichever limit is reached first will take effect.</para>

</sect3>

<sect3>
<title>Not working examples</title>

<para><emphasis>NOT</emphasis> working, as only
<emphasis>one</emphasis>, time-period <emphasis>or</emphasis> job-limit
is defined)</para>

<screen><userinput><command>lpadmin</command> <option>-p</option> <parameter>danka_infotec_P320</parameter> <option>-o</option> <parameter>job-quota-period=604800</parameter></userinput>

<userinput><command>lpadmin</command> <option>-p</option> <parameter>danka_infotec_FullColor</parameter> <option>-o</option> <parameter>job-page-limit=100</parameter></userinput>

<userinput><command>lpadmin</command> <option>-p</option> <parameter>danka_infotec_HiSpeed</parameter> <option>-o</option> <parameter>job-k-limit=1024</parameter></userinput></screen>

</sect3>

<sect3>
<title>Related Error Messages</title>

<para>Once a user reaches his quota limit, he'll get a
<errortype>client-error-not-possible</errortype> message, if he wants to
print.</para>

</sect3>

</sect2>

<sect2>
<title>Installing a <quote>raw</quote> printer</title>

<para>There are different ways to define a <quote>raw</quote>
printer. One comfortable one is to use the <command>lpadmin</command>
command.  Just don't define a &PPD; file to be used for that printer and
it will be a raw one:</para>

<screen><userinput><command>lpadmin</command> <option>-p</option> <parameter>Raw_Danka_infotec</parameter> <option>-E</option> <option>-v</option> <parameter>lpd://10.160.16.137/PORT1</parameter></userinput></screen>

<para>Raw printer queues are those which don't touch the print file to
transform it to a different file format. You need this for example when
printing from &Windows; clients via Samba through a &CUPS; server to a
<acronym>PCL</acronym> printer: in this case the &Windows; side printer
driver would generate the finished print file format for the target
printer and filtering it through &CUPS; filters would only harm the
purpose. Under certain circumstances (if you want to make sure that the
file goes to the printer <quote>unfiltered</quote> by &CUPS;) the
<quote><command>lpadmin</command> without a &PPD;</quote> comes in
handy.</para>

</sect2>

</sect1>
<sect1 id="troubleshooting-cups">
<title>Troubleshooting &CUPS; in &tdeprint;</title>

<para>This section of the &tdeprint; Handbook will live from the
readers' feedback. Here is just a small beginning.</para>

<sect2>
<title>Error Messages</title>

<qandaset>
<qandaentry>
<question>
<para>What does the error
<errortype>client-error-bad-request</errortype> mean?</para>
</question>
<answer>
<para>The user sent a file to the &CUPS; which the server could not
process. You get this also upon sending an <quote>empty</quote>
file.</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>And <errortype>client-error-not-possible</errortype>?</para>
</question>
<answer>
<para>User is either not allowed to print to a certain printer or has
achieved his quota (based on file size and/or page number)</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>How about <errortype>client-error-not-found</errortype>?</para>
</question>
<answer>
<para>The user tried to access a nonexistent resource on the &CUPS;
server, such as trying to print a nonexistent file, or one that you are
denied permission to read.</para>
</answer>

</qandaentry>
</qandaset>

</sect2>

<sect2>
<title>Questions and Answers</title>

<qandaset>
<qandaentry>
<question>
<para>Why can't I re-start my jobs?</para>
</question>
<answer>
<para>To be able to re-start your <quote>completed</quote> jobs from the
web interface, you need a setting in the
<filename>/etc/cups/cupsd.conf</filename> file: set
<userinput>PreserveJobFiles True</userinput>.</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>How do I get rid of the long list of completed jobs in the web
interface?</para>
</question>
<answer>
<para>TODO</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>How does page accounting work?</para>
</question>
<answer>
<para>&CUPS; does the <quote>print accounting</quote> by passing nearly
every job through the <quote>pstops</quote> filter.  This one does,
amongst other things, the page counting. Output of this filter there may
be piped into other filters (like pstoraster --> rastertopcl) or sent to
the printer directly (if it is a &PostScript; printer).</para>

<para>In any case, this works for network, parallel, serial or
<acronym>USB</acronym> printers the same. For pstops to work, it needs
<acronym>DSC</acronym>, Document Structuring Convention compliant
&PostScript; (or near-equivalent) as input. So it calculates the pages
during filtering on the print server and writes info about every single
page (what time, which user, which job-ID and -name, which printer, how
many copies of which pages of the document, how many kilo-bytes?) into
<filename>/var/log/cups/page_log</filename>.</para>

<para>By the way: on my personal <quote>wishlist</quote> is a hack of
<quote>webalizer</quote> to read and analyze the page_log and give a
similar output.  Anyone?</para>

<para>However, it is <emphasis>not</emphasis> giving correct results in
the following cases:</para>

<itemizedlist>
<listitem>
<para>The printer jams and maybe therefor throw away the job (real live
experience; or maybe throwing away the job because of problems with the
data format)</para>
</listitem>
<listitem>
<para>Jobs printed as <quote>raw</quote> are always counted as size of 1
page (and maybe multiple copies).</para>
</listitem>
</itemizedlist>

<para>Therefore the page accounting of &CUPS; is <quote>only</quote>
an approximation (in many cases an excellent or at least good one, in
others a quite poor one). The only reliable print count is the one
done by the internal printer counter. (Because this is the one you pay
for, if you are on a <quote>click price</quote> or similar.)  Some, by
far not most, printers can be queried remotely for that information
via <acronym>SNMP</acronym> (Simple Network Management Protocol). That
means, in a bigger network with many different printers there
<emphasis>is</emphasis> just no completely reliable and accurate page
accounting tool!</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>Why doesn't page-accounting work with &Windows; clients?</para>
</question>
<answer>
<para>From &Windows; clients jobs nearly always need to be sent as
<quote>raw</quote>. Why? If &CUPS; works as a print server for &Windows;
clients using the original native &Windows; driver for the target print
device, this guarantees the correct formatting of the job on the clients
already; therefor the server should not touch it and print
<quote>raw</quote>; therefor no filtering is started (and this is not
even possible as the input from the clients is not &PostScript; as
pstops expects; hence no page-count other than the default
<quote>1</quote>.</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>How do I get a list of available options for a given printer or a
&PPD; file?</para>
</question>
<answer>
<para>See the man page for the <command>lpoptions</command> command. You
may investigate a &CUPS;-enabled box about any option of its available
printers. There is no need to have the printer installed locally. As
long as the printer is available locally (through the &CUPS;
<quote>printer browsing</quote> feature), it will also work
remote.</para>

<para>To query for a printers' option typing
<userinput><command>lpoptions</command> <option>-p</option>
<parameter>HitachiDDP70MicroPress</parameter>
<option>-l</option></userinput> will give a long listing of all
available options as read from the &PPD; file for the given
Hitachi-Printer (in my case installed on remote server
transmeta). Remote server <systemitem
class="systemname">Transmeta</systemitem> and its &CUPS; daemon as well
as the localhost's &CUPS; daemon need to be up and running for this to
succeed.</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>How do I read the listing retrieved by the
<command>lpoptions</command> command?</para>
</question>

<answer>
<para>You know that for &PostScript; printer manufacturers it is
<quote>legal</quote> to define their own internal names and procedures
even for standard &PostScript; options. As long as the driver is able to
retrieve the option from the &PPD; and show it to the user in a way that
he understands it everything is OK. But what do <emphasis>you</emphasis>
do, if you want to use some obscure printer options on the command line?
How do you find out its exact syntax?</para>

<para>Let's take an example. Looking at Hitachi's DDP70 printer and how
it implements duplex printing is revealing somehow. How do you tell how
to print double sided? duplex or Duplex? Or another name altogether?.</para>

<screen><userinput><command>lpoptions</command> <option>-h</option> <parameter>transmeta</parameter> <option>-p</option> <parameter>Hitachi_DDP70_ClusterPrintingSystem</parameter> <option>-l</option> | <command>grep</command> <parameter>uplex</parameter></userinput></screen>

<para>This leads to the output</para>

<screen><computeroutput>TR-Duplex/Duplex: False *True</computeroutput></screen>

<para>This is to be interpreted like follows:</para>

<itemizedlist>
<listitem>
<para>The name of the investigated option is
<option>TR-Duplex</option>;</para>
</listitem>
<listitem>
<para>Behind the slash you see the translation of the option, as it
should be shown in a &GUI; or Web interface
(<quote>Duplex</quote>);</para>
</listitem>
<listitem>
<para>The option may take one of the two values
<parameter>False</parameter> or <parameter>True</parameter>;</para>
</listitem>
<listitem>
<para>The present setting is <parameter>True</parameter> to be
recognized by the marking with a star <literal>*</literal>.</para>
</listitem>
</itemizedlist>

<para>To override the present default setting (duplex) and print a job
in simplex, you need to use the following command: </para>

<screen><userinput><command>lpr</command> <option>-P</option> <parameter>Hitachi_DDP70_ClusterPrintingSystem</parameter> <option>-o</option> <parameter>TR-Duplex=False</parameter> <parameter>/path/to/your/printjob</parameter></userinput></screen>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>How do I get a nicely formatted listing of available options for a
given printer or &PPD;?</para>
</question>
<answer>
<para>Use the <command>lphelp</command> command which may be installed
on your system locally. There is not yet a man page for
<command>lphelp</command>.</para>

<screen><userinput><command>lphelp</command> <parameter>infotecP450</parameter></userinput></screen>

<para>This lists the available options for the named printer. It is
nicely formatted and does explain every available option and how to use
it. You can query different printers' options at once:</para>

<screen><userinput><command>lphelp</command> <parameter>infotec7410color</parameter> <parameter>DANKA_fullcolor_D2000</parameter> <parameter>HP_ColorLaserJet8550</parameter></userinput></screen>

<para>It also works for &PPD; files. Just specify the path to the
&PPD;:</para>

<screen><userinput><command>lphelp</command> <filename>/home/kurt/PPDs/HP-ColorLaserJet8550.ppd</filename></userinput></screen>
</answer>
</qandaentry>
</qandaset>

</sect2>
<sect2>
<title>Solving Problems</title>

<para>No system is perfect. Here are some commonly seen traps people
have fallen into.</para>

<qandaset>
<qandaentry>
<question>
<para>My printer named <quote>3-lp-duplex</quote> shows erratic
behavior.  What's wrong?</para>
</question>
<answer>
<para>The printer names used in &CUPS; shall start with a letter and may
contain up to 128 letters, numbers or underscores. Using dashes may lead
to problems. Speaking about naming: printer names in &CUPS; are not case
sensitive. So a printer named <systemitem
class="resource">Best_of_Danka</systemitem> will be the same as
<systemitem class="resource">best_of_danka</systemitem> or <systemitem
class="resource">BEST_OF_DANKA</systemitem>. (This is a requirement of
&IPP;, which &CUPS; is fully compliant with).</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>Why do I get <errortype>Unable to connect to SAMBA host:
Success</errortype> with my printer shares from &Windows; accessed via
Samba?</para>
</question>
<answer>
<para>Are the rights on the remote &Windows; box set correctly for you?
Are you actually allowed to print on the &Windows; shared
printer?</para>
</answer>
</qandaentry>

<qandaentry>
<question>
<para>My files for printer <systemitem class="resource">lp</systemitem>
sometimes mysteriously disappear and two days later I am told they got
printed on a printer three floors below my office. What is going on?</para>
</question>
<answer>
<para>Believe me, it is very unlikely that your printer is the only one
with the name <systemitem class="resource">lp</systemitem>.  Maybe
&CUPS; is playing a trick on you. As you might have the setting
<quote>ImplicitClasses On</quote> activated, &CUPS; tries to stuff all
printers it sees on the network into a <quote>Class</quote> name lp. All
jobs destined to lp are sent to this class and the first available
member prints it. So if you had this nice fellow (who listened closely
when you raved about &CUPS; and &tdeprint;) install &CUPS; and poke
around the system...get the idea?</para>

<para>Take my advice: choose a unique name for any network printer!
(Mind you, the one on your parallel port also turns out to be a network
printer for the rest of the world if you don't take care of your
settings).</para>
</answer>
</qandaentry>
</qandaset>
</sect2>
</sect1>
</chapter>