# &CUPS; options presently not available through &kcontrol;

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

## Overview of provided features

All of the most often used features and functions &CUPS; provides are supported in &kdeprint;.

- Printer management is supported: add, remove, modify, configure, test, disable, enable ...

- Job management is supported: cancel, hold, release, move to different printer

- Print options: for full control as provided by &CUPS;.

## Where to find help when using &CUPS;

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 http://localhost:631/ for a start. There you find a link to locally available &CUPS; documentation in HTML and PDF if you are new to &CUPS;.

&CUPS; is accessible through other means than &kdeprint;: 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.

This is also true for &kdeprint;. 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.

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.

A complete list of available files and man pages should always be in the &CUPS; Software Administrator Manual (http://localhost:631/sam.html#FILES. In the &konqueror; &URL;/location field, type `man:/lpadmin` and `man:/cupsd.conf` 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.

### How to find &CUPS; related man pages

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

    kurt@transmeta:~
    > apropos cups

    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

## Outside &kdeprint;: Hints & Tips Tricks with &CUPS; on the Commandline

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

### Allowing or denying printer access for certain users

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

    lpadmin -pHeidelbergDigimaster9110 -v lpd:/10.160.16.99/mqueue -u allow:kurt,sylvi,hansjoerg -E -P /home/kurt/PPDs/DVHV.ppd

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 client-error-not-possible.

    lpadmin -p HeidelbergDigimaster9110 -v lpd:/10.160.16.99/mqueue -u deny:tackat,boss,waba -E -P /home/kurt/PPDs/DVHV.ppd

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

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.

### Imposing Quotas for certain printers

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.

Quotas can be set with the `-o` option when installing a printer with the `lpadmin` 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):

- With &CUPS; you may have pagecount- and filesize-based quotas for individual printers.

- Quotas are calculated for each user individually (so a single set of limits applies to all users for the printer concerned).

- Quotas include banner pages (if those are used).

- This means: you can limit every user to 20 pages per day on an expensive printer, but you cannot limit every user except Kurt or root.

- There are `job-k-limit`, `job-page-limit`, and `job-quota-period` options to give when setting up a printer.

- `job-quota-period` 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.)

- For quotas to be enforced, the time-period plus at least one job-limit must be set to non-zero.

- The default value of 0 for `job-k-limit` specifies that there is no limit.

- The default value of 0 for `job-page-limit` specifies that there is no limit.

- The default value of 0 for `job-quota-period` specifies that the limits apply to all jobs that have been printed by a user that are still known to the system.

#### Working Examples:

Working, as both, time-period plus one or both job-limits are defined

    lpadmin -p danka_infotec_4850 -o job-quota-period=604800 -o job-k-limit=1024

This sets a limit of a file size of 1 MB (in total) for each user of existing printer danka_infotec_4850 during one week.

    lpadmin p danka_infotec_4105 -o job-quota-period=604800 -o job-page-limit=100

This sets a limit of 100 pages (in total) for each user of existing printer danka_infotec_4105 during one week.

    lpadmin -p danka_infotec_P450 -o job-quota-period=604800 -o job-k-limit=1024 -o job-page-limit=100

This sets a combined limit of 1 MB (in total) and 100 pages (in total) for each user of existing printer danka_infotec_P450 during one week. Whichever limit is reached first will take effect.

#### Not working examples

NOT working, as only one, time-period or job-limit is defined)

    lpadmin -p danka_infotec_P320 -o job-quota-period=604800

    lpadmin -p danka_infotec_FullColor -o job-page-limit=100

    lpadmin -p danka_infotec_HiSpeed -o job-k-limit=1024

#### Related Error Messages

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

### Installing a raw printer

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

    lpadmin -p Raw_Danka_infotec -E -v lpd://10.160.16.137/PORT1

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 PCL 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 unfiltered by &CUPS;) the `lpadmin` without a &PPD; comes in handy.

## Troubleshooting &CUPS; in &kdeprint;

This section of the &kdeprint; Handbook will live from the readers' feedback. Here is just a small beginning.

### Error Messages

What does the error client-error-bad-request mean?

The user sent a file to the &CUPS; which the server could not process. You get this also upon sending an empty file.

And client-error-not-possible?

User is either not allowed to print to a certain printer or has achieved his quota (based on file size and/or page number)

How about client-error-not-found?

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.

### Questions and Answers

Why can't I re-start my jobs?

To be able to re-start your completed jobs from the web interface, you need a setting in the `/etc/cups/cupsd.conf` file: set `PreserveJobFiles True`.

How do I get rid of the long list of completed jobs in the web interface?

TODO

How does page accounting work?

&CUPS; does the print accounting by passing nearly every job through the pstops 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).

In any case, this works for network, parallel, serial or USB printers the same. For pstops to work, it needs DSC, 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 `/var/log/cups/page_log`.

By the way: on my personal wishlist is a hack of webalizer to read and analyse the page_log and give a similar output. Anyone?

However, it is not giving correct results in the following cases:

- The printer jams and maybe therefore throw away the job (real live experience; or maybe throwing away the job because of problems with the data format)

- Jobs printed as raw are always counted as size of 1 page (and maybe multiple copies).

Therefore the page accounting of &CUPS; is only 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 click price or similar.) Some, by far not most, printers can be queried remotely for that information via SNMP (Simple Network Management Protocol). That means, in a bigger network with many different printers there is just no completely reliable and accurate page accounting tool!

Why doesn't page-accounting work with &Windows; clients?

From &Windows; clients jobs nearly always need to be sent as raw. 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 raw; 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 1.

How do I get a list of available options for a given printer or a &PPD; file?

See the man page for the `lpoptions` 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; printer browsing feature), it will also work remote.

To query for a printers' option typing ``lpoptions` `-p` `HitachiDDP70MicroPress` `-l`` 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 Transmeta and its &CUPS; daemon as well as the localhost's &CUPS; daemon need to be up and running for this to succeed.

How do I read the listing retrieved by the `lpoptions` command?

You know that for &PostScript; printer manufacturers it is legal 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 you do, if you want to use some obscure printer options on the command line? How do you find out its exact syntax?

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?.

    lpoptions -h transmeta -p Hitachi_DDP70_ClusterPrintingSystem -l | grep uplex

This leads to the output

    TR-Duplex/Duplex: False *True

This is to be interpreted like follows:

- The name of the investigated option is `TR-Duplex`;

- Behind the slash you see the translation of the option, as it should be shown in a &GUI; or Web interface (Duplex);

- The option may take one of the two values `False` or `True`;

- The present setting is `True` to be recognised by the marking with a star `*`.

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

    lpr -P Hitachi_DDP70_ClusterPrintingSystem -o TR-Duplex=False /path/to/your/printjob

How do I get a nicely formatted listing of available options for a given printer or &PPD;?

Use the `lphelp` command which may be installed on your system locally. There is not yet a man page for `lphelp`.

    lphelp infotecP450

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:

    lphelp infotec7410color DANKA_fullcolor_D2000 HP_ColorLaserJet8550

It also works for &PPD; files. Just specify the path to the &PPD;:

    lphelp /home/kurt/PPDs/HP-ColorLaserJet8550.ppd

### Solving Problems

No system is perfect. Here are some commonly seen traps people have fallen into.

My printer named 3-lp-duplex shows erratic behaviour. What's wrong?

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 Best_of_Danka will be the same as best_of_danka or BEST_OF_DANKA. (This is a requirement of &IPP;, which &CUPS; is fully compliant with).

Why do I get Unable to connect to SAMBA host: Success with my printer shares from &Windows; accessed via Samba?

Are the rights on the remote &Windows; box set correctly for you? Are you actually allowed to print on the &Windows; shared printer?

My files for printer lp 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?

Believe me, it is very unlikely that your printer is the only one with the name lp. Maybe &CUPS; is playing a trick on you. As you might have the setting ImplicitClasses On activated, &CUPS; tries to stuff all printers it sees on the network into a Class 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 &kdeprint;) install &CUPS; and poke around the system...get the idea?

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).