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CUPS Software Administrators Manual
CUPS Software Administrators Manual
CUPS-SAM-1.1.23
Easy Software Products
Copyright 1997-2005, All Rights Reserved
Preface
1 - Printing System Overview
2 - Building and Installing CUPS
3 - Managing Printers
4 - Printer Classes
5 - Client Setup
6 - Printing System Management
7 - Printing with Other Systems
A - Software License Agreement
B - Common Network Settings
C - Printer Drivers
D - List of Files
E - Troubleshooting Common Problems
This software administrators manual provides printer administration
information for the Common UNIX Printing SystemTM ("CUPS
TM"), version 1.1.23.
CUPS provides a portable printing layer for UNIX®-based operating
systems. It has been developed by Easy
Software Products to promote a standard printing solution for all
UNIX vendors and users. CUPS provides the System V and Berkeley
command-line interfaces.
CUPS uses the Internet Printing Protocol ("IPP") as the basis for
managing print jobs and queues. The Line Printer Daemon ("LPD") Server
Message Block ("SMB"), and AppSocket (a.k.a. JetDirect) protocols are
also supported with reduced functionality. CUPS adds network printer
browsing and PostScript Printer Description ("PPD") based printing
options to support real-world printing under UNIX.
CUPS includes an image file RIP that supports printing of image files
to non-PostScript printers. A customized version of GNU Ghostscript
7.05 for CUPS called ESP Ghostscript is available separately to support
printing of PostScript files within the CUPS driver framework. Sample
drivers for Dymo, EPSON, HP, and OKIDATA printers are included that use
these filters.
Drivers for thousands of printers are provided with our ESP Print Pro
software, available at:
http://www.easysw.com/printpro/
CUPS is licensed under the GNU General Public License and GNU Library
General Public License. Please contact Easy Software Products for
commercial support and "binary distribution" rights.
This software administrators manual is organized into the following
sections:
Various font and syntax conventions are used in this guide. Examples
and their meanings and uses are explained below:
| Example | | Description |
|---|
| |
lpstat
lpstat(1) | | The names of commands;
the first mention of a command or function in a chapter is followed by
a manual page section number. |
| |
/var
/usr/share/cups/data/testprint.ps | |
File and directory names. |
| |
| Request ID is Printer-123 |
| Screen output. |
| |
| lp -d printer filename ENTER |
| Literal user input; special keys like ENTER are
in ALL CAPS. |
| |
| 12.3 | | Numbers in the text are
written using the period (.) to indicate the decimal point. |
The following abbreviations are used throughout this manual:
- kb
- Kilobytes, or 1024 bytes
- Mb
- Megabytes, or 1048576 bytes
- Gb
- Gigabytes, or 1073741824 bytes
- CUPS Software Programmers Manual
- A programmer guide for interfacing with and/or extending the CUPS
software.
- CUPS Software Users Manual
- An end-user guide for using the CUPS software.
This chapter provides an overview of how the Common UNIX Printing
System works.
For years the printing problem has plagued UNIX. Unlike
Microsoft® Windows® or Mac OS, UNIX has no standard interface or system
in place for supporting printers. Among the solutions currently
available, the Berkeley and System V printing systems are the most
prevalent.
These printing systems support line printers (text only) or
PostScript printers (text and graphics), and with some coaxing they can
be made to support a full range of printers and file formats. However,
because each varient of the UNIX operating system uses a different
printing system than the next developing printer drivers for a wide
range of printers and operating systems is extremely difficult. That
combined with the limited volume of customers for each UNIX varient has
forced most printer vendors to give up supporting UNIX entirely.
CUPS is designed to eliminate the printing problem. One common
printing system can be used by all UNIX varients to support the
printing needs of users. Printer vendors can use its modular filter
interface to develop a single driver program that supports a wide range
of file formats with little or no effort. Since CUPS provides both the
System V and Berkeley printing commands, users (and applications) can
reap the benefits of this new technology with no changes.
CUPS is based upon an emerging Internet standard called the Internet
Printing Protocol. IPP has been embraced by dozens of printer and
printer server manufacturers and is supported by Microsoft Windows
2000.
IPP defines a standard protocol for printing as well as managing
print jobs and printer options like media size, resolution, and so
forth. Like all IP-based protocols, IPP can be used locally or over the
Internet to printers hundreds or thousands of miles away. Unlike other
protocols, however, IPP also supports access control, authentication,
and encryption, making it a much more capable and secure printing
solution than older ones.
IPP is layered on top of the Hyper-Text Transport Protocol ("HTTP")
which is the basis of web servers on the Internet. This allows users to
view documentation, check status information on a printer or server,
and manage their printers, classes, and jobs using their web browser.
CUPS provides a complete IPP/1.1 based printing system that provides
Basic, Digest, and local certificate authentication and user, domain,
or IP-based access control. TLS encryption will be available in future
versions of CUPS.
Each file or set of files that is submitted for printing is called a
job. Jobs are identified by a unique number starting at 1 and are
assigned to a particular destination, usually a printer. Jobs can also
have options associated with them such as media size, number of copies,
and priority.
CUPS supports collections of printers known as classes. Jobs
sent to a class are forwarded to the first available printer in the
class.
Filters allow a user or application to print many types of files
without extra effort. Print jobs sent to a CUPS server are filtered
before sending them to a printer. Some filters convert job files to
different formats that the printer can understand. Others perform page
selection and ordering tasks.
CUPS provides filters for printing many types of image files, HP-GL/2
files, PDF files, and text files. CUPS also supplies PostScript and
image file Raster Image Processor ("RIP") filters that convert
PostScript or image files into bitmaps that can be sent to a raster
printer.
Backends perform the most important task of all - they send the
filtered print data to the printer.
CUPS provides backends for printing over parallel, serial, and USB
ports, and over the network via the IPP, JetDirect (AppSocket), and
Line Printer Daemon ("LPD") protocols. Additional backends are
available in network service packages such as the SMB backend included
with the popular SAMBA software.
Backends are also used to determine the available devices. On startup
each backend is asked for a list of devices it supports, and any
information that is available. This allows the parallel backend to tell
CUPS that an EPSON Stylus Color 600 printer is attached to parallel
port 1, for example.
Printer drivers in CUPS consist of one of more filters specific to a
printer. CUPS includes sample printer drivers for Hewlett-Packard
LaserJet and DeskJet printers and EPSON 9-pin, 24-pin, Stylus Color,
and Stylus Photo printers. While these drivers do not generate optimal
output for the different printer models, they do provide basic printing
and demonstrate how you can write your own printer drivers and
incorporate them into CUPS.
Printers and classes on the local system are automatically shared
with other systems on the network. This allows you to setup one system
to print to a printer and use this system as a printer server or spool
host for all of the others. Users may then select a local printer by
name or a remote printer using "name@server".
CUPS also provides implicit classes, which are collections of
printers and/or classes with the same name. This allows you to setup
multiple servers pointing to the same physical network printer, for
example, so that you aren't relying on a single system for printing.
Because this also works with printer classes, you can setup multiple
servers and printers and never worry about a single point of failure
unless all of the printers and servers go down!
This chapter shows how to build and install the Common UNIX Printing
System. If you are installing a binary distribution from the CUPS web
site, proceed to the section titled, Installing a
Binary Distribution.
This section describes how to compile and install CUPS on your system
from the source code.
You'll need ANSI-compliant C and C++ compilers to build CUPS on your
system. As its name implies, CUPS is designed to run on the UNIX
operating system, however the CUPS interface library and most of the
filters and backends supplied with CUPS should also compile and run
under Microsoft Windows.
For the image file filters and PostScript RIP, you'll need the JPEG,
PNG, TIFF, and ZLIB libraries. CUPS will build without these, but with
significantly reduced functionality. Easy Software Products maintains a
mirror of the current versions of these libraries at:
ftp://ftp.easysw.com/pub/libraries
If you make changes to the man pages you'll need GNU groff or another
nroff-like package. GNU groff is available from:
ftp://ftp.gnu.org/pub/groff
The documentation is formatted using the HTMLDOC software. If you
need to make changes you can get the HTMLDOC software from:
http://www.easysw.com/htmldoc
Finally, you'll need a make program that understands the
include directive - FreeBSD, NetBSD, and OpenBSD
developers should use the gmake program.
CUPS uses GNU autoconf to configure the makefiles and source code for
your system. Type the following command to configure CUPS for your
system:
./configure ENTER
The default installation will put the CUPS software in the /etc
, /usr, and /var directories on your system, which
will overwrite any existing printing commands on your system. Use the
--prefix option to install the CUPS software in another location:
./configure --prefix=/some/directory ENTER
If the PNG, JPEG, TIFF, and ZLIB libraries are not installed in a
system default location (typically /usr/include and
/usr/lib) you'll need to set the CFLAGS,
CXXFLAGS, and LDFLAGS environment variables prior to
running configure:
setenv CFLAGS "-I/some/directory" ENTER
setenv CXXFLAGS "-I/some/directory" ENTER
setenv LDFLAGS "-L/some/directory" ENTER
setenv DSOFLAGS "-L/some/directory" ENTER
./configure ... ENTER
or:
CFLAGS="-I/some/directory"; export CFLAGS ENTER
CXXFLAGS="-I/some/directory"; export CXXFLAGS ENTER
LDFLAGS="-L/some/directory"; export LDFLAGS ENTER
DSOFLAGS="-L/some/directory"; export DSOFLAGS ENTER
./configure ... ENTER
To enable support for encryption, you'll also want to add the
"--enable-ssl" option:
./configure --enable-ssl
SSL and TLS support require the OpenSSL library, available at:
http://www.openssl.org
If the OpenSSL headers and libraries are not installed in the
standard directories, use the --with-openssl-includes and
--with-openssl-libs options:
./configure --enable-ssl \
--with-openssl-includes=/foo/bar/include \
--with-openssl-libs=/foo/bar/lib
Once you have configured things, just type:
make ENTER
to build the software.
Use the "install" target to install the software:
make install ENTER
| WARNING:
Installing CUPS will overwrite your existing printing system. If you
experience difficulties with the CUPS software and need to go back to
your old printing system, you will need to reinstall the old printing
system from your operating system CDs.
|
Once you have installed the software you can start the CUPS server by
typing:
/usr/sbin/cupsd ENTER
CUPS comes in a variety of binary distribution formats. Easy Software
Products provides binaries in TAR format with installation and removal
scripts ("portable" distributions), and in RPM and DPKG formats for Red
Hat and Debian-based distributions. Portable distributions are
available for all platforms, while the RPM and DPKG distributions are
only available for Linux.
| WARNING:
Installing CUPS will overwrite your existing printing system. If you
experience difficulties with the CUPS software and need to go back to
your old printing system, you will need to remove the CUPS software
with the provided script and/or reinstall the old printing system from
your operating system CDs.
|
To install the CUPS software from a portable distribution you will
need to be logged in as root; doing an su is good enough.
Once you are the root user, run the installation script with:
./cups.install ENTER
After asking you a few yes/no questions the CUPS software will be
installed and the scheduler will be started automatically.
To install the CUPS software from an RPM distribution you will need
to be logged in as root; doing an su is good enough. Once
you are the root user, run RPM with:
rpm -e lpr
rpm -i cups-1.1-linux-M.m.n-intel.rpm ENTER
After a short delay the CUPS software will be installed and the
scheduler will be started automatically.
To install the CUPS software from a Debian distribution you will need
to be logged in as root; doing an su is good enough. Once
you are the root user, run dpkg with:
dpkg -i cups-1.1-linux-M.m.n-intel.deb ENTER
After a short delay the CUPS software will be installed and the
scheduler will be started automatically.
This chapter describes how to add your first printer and how to
manage your printers.
Each printer queue has a name associated with it; the printer name
must start with any printable character except " ", "/", and "@". It
can contain up to 127 letters, numbers, and the underscore (_). Case is
not significant, e.g. "PRINTER", "Printer", and "printer" are
considered to be the same name.
Printer queues also have a device associated with them. The device
can be a parallel port, a network interface, and so forth. Devices
within CUPS use Uniform Resource Identifiers ("URIs") which are a more
general form of Uniform Resource Locators ("URLs") that are used in
your web browser. For example, the first parallel port in Linux usually
uses a device URI of parallel:/dev/lp1.
You can see a complete list of supported devices by running the
lpinfo(8) command:
lpinfo -v ENTER
network socket
network http
network ipp
network lpd
direct parallel:/dev/lp1
serial serial:/dev/ttyS1?baud=115200
serial serial:/dev/ttyS2?baud=115200
direct usb:/dev/usb/lp0
network smb
The -v option specifies that you want a list of
available devices. The first word in each line is the type of device
(direct, file, network, or serial) and is followed by the device URI or
method name for that device. File devices have device URIs of the form
file:/directory/filename while network devices use the more
familiar method://server or method://server/path
format.
Finally, printer queues usually have a PostScript Printer Description
("PPD") file associated with them. PPD files describe the capabilities
of each printer, the page sizes supported, etc., and are used for
PostScript and non-PostScript printers. CUPS includes PPD files for HP
LaserJet, HP DeskJet, EPSON 9-pin, EPSON 24-pin, and EPSON Stylus
printers.
CUPS provides two methods for adding printers: a command-line program
called lpadmin(8) and a Web interface. The lpadmin
command allows you to perform most printer administration tasks from
the command-line and is located in /usr/sbin. The Web
interface is located at:
http://localhost:631/admin
and steps you through printer configuration. If you don't like
command-line interfaces, try the Web interface
instead.
Run the lpadmin command with the -p option
to add a printer to CUPS:
/usr/sbin/lpadmin -p printer -E -v device -m ppd ENTER
For a HP DeskJet printer connected to the parallel port this would
look like:
/usr/sbin/lpadmin -p DeskJet -E -v parallel:/dev/lp1 -m deskjet.ppd ENTER
Similarly, a HP LaserJet printer using a JetDirect network interface
at IP address 11.22.33.44 would be added with the command:
/usr/sbin/lpadmin -p LaserJet -E -v socket://11.22.33.44 -m laserjet.ppd ENTER
As you can see, deskjet.ppd and laserjet.ppd
are the PPD files for the HP DeskJet and HP LaserJet drivers included
with CUPS. You'll find a complete list of PPD files and the printers
they will work with in Appendix C, "Printer
Drivers".
For a dot matrix printer connected to the serial port, this might
look like:
/usr/sbin/lpadmin -p DotMatrix -E -m epson9.ppd \
-v serial:/dev/ttyS0?baud=9600+size=8+parity=none+flow=soft ENTER
Here you specify the serial port (e.g. S0,S1, d0, d1), baud rate
(e.g. 9600, 19200, 38400, 115200, etc.), number of bits, parity, and
flow control. If you do not need flow control, delete the "+flow=soft"
portion.
The CUPS web server provides a user-friendly "wizard" interface for
adding your printers. Rather than figuring out which device URI and PPD
file to use, you can instead click on the appropriate listings and fill
in some simple information. Enter the following URL in your web browser
to begin:
http://localhost:631/admin
Click on the Add Printer button to add a printer.
The lpadmin command enables you to perform most printer
administration tasks from the command-line. You'll find lpadmin
in the /usr/sbin directory.
Run the lpadmin command with the -p option
to add or modify a printer:
/usr/sbin/lpadmin -p printer options ENTER
The options arguments can be any of the following:
- -c class
- Adds the named printer to printer class class. If the
class does not exist then it is created.
- -i interface
- Copies the named interface script to the printer.
Interface scripts are used by System V printer drivers. Since all
filtering is disabled when using an interface script, scripts generally
should not be used unless there is no other driver for a printer.
- -m model
- Specifies a standard printer driver which is usually a PPD file.
PPD's are usually stored under the /usr/share/cups/model/
directory structure. A list of all available models can be displayed
using the
lpinfo command with the -m option.
A list of printer drivers included with CUPS can be found in
Appendix C, "Printer Drivers".
- -r class
- Removes the named printer from printer class class. If
the resulting class becomes empty then it is removed.
- -v device-uri
- Sets the device for communicating with the printer. If a job is
currently printing on the named printer then the job will be restarted
and sent to the new device.
- -D info
- Provides a textual description of the printer, e.g. "John's Personal
Printer".
- -E
- Enables the printer and accepts job. This option is equivalent to
running the
enable(1) and accept(8) commands
on the printer.
- -L location
- Provides a textual location for the printer, e.g. "Computer Lab 5".
- -P ppd-file
- Specifies a local PPD file for the printer driver.
Run the lpadmin command with the -x option
to delete a printer:
/usr/sbin/lpadmin -x printer ENTER
Run the lpadmin command with the -d option
to set a default printer:
/usr/sbin/lpadmin -d printer ENTER
The default printer can be overridden by the user using the
lpoptions(1) command.
The enable and disable commands start and
stop printer queues, respectively:
/usr/bin/enable printer ENTER
/usr/bin/disable printer ENTER
Printers that are disabled may still accept jobs for printing, but
won't actually print any files until they are restarted. This is useful
if the printer malfunctions and you need time to correct the problem.
Any queued jobs are printed after the printer is enabled (started).
The accept and reject commands accept and
reject print jobs for the named printer, respectively:
/usr/sbin/accept printer ENTER
/usr/sbin/reject printer ENTER
As noted above, a printer can be stopped but accepting new print
jobs. A printer can also be rejecting new print jobs while it finishes
those that have been queued. This is useful for when you must perform
maintenance on the printer and will not have it available to users for
a long period of time.
CUPS supports page and size-based quotas for each printer. The quotas
are tracked individually for each user, but a single set of limits
applies to all users for a partiuclar printer. For example, you can
limit every user to 5 pages per day on an expensive printer, but you
cannot limit every user except Johnny.
The job-k-limit, job-page-limit, and job-quota-peiod
options determine whether and how quotas are enforced for a printer.
The job-quota-period option determines the time interval for
quota tracking. The interval is expressed in seconds, so a day is
86,400, a week is 604,800 and a month is 2,592,000 seconds. The
job-k-limit option specifies the job size limit in killobytes. The
job-page-limit option specifies the number of pages limit.
For quotas to be enforced, the period and at least one of the limits
must be set to a non-zero value. The following options will enable
quotas:
/usr/sbin/lpadmin -p printer -o job-quota-period=604800 \
-o job-k-limit=1024 ENTER
/usr/sbin/lpadmin -p printer -o job-quota-period=604800 \
-o job-page-limit=100 ENTER
Or, you can combine all three options on the same line.
The -u option of the lpadmin command
controls which users can print to a printer. The default configuration
allows all users to print to a printer:
/usr/sbin/lpadmin -p printer -u allow:all ENTER
CUPS supports allow and deny lists so that you can specify a list of
users who are allowed to print or not allowed to print. Along with your
list of users, you can specify whether they are allowed or not allowed
to use the printer:
/usr/sbin/lpadmin -p printer -u allow:peter,paul,mary ENTER
This command allows peter, paul, and mary to print to the named
printer, but all other users cannot print. The command:
/usr/sbin/lpadmin -p printer -u deny:peter,paul,mary ENTER
has the opposite effect. All users except peter, paul, and mary will
be able to print to the named printer.
You can control access by UNIX groups as well by placing an "@"
character before each group name. The command:
/usr/sbin/lpadmin -p printer -u allow:peter,paul,mary,@printgods ENTER
allows the users peter, paul, and mary to print, as well as any user
in the printgods group to print.
| NOTE:
The allow and deny options are not cummulative. That
is, you must provide the complete list of users to allow or deny each
time.
Also, CUPS only maintains one list of users - the list can allow or
deny users from printing. If you specify an allow list and then specify
a deny list, the deny list will replace the allow list - only one list
is active at any time.
|
The Web interface is located at:
http://localhost:631/admin
From there you can perform all printer management tasks with a few
simple mouse clicks.
This chapter describes what printer classes are and how to manage
them.
CUPS provides collections of printers called printer classes.
Jobs sent to a class are forwarded to the first available printer in
the class. Classes can themselves be members of other classes, so it is
possible for you to define very large, distributed printer classes for
high-availability printing.
CUPS also supports implicit classes. Implicit classes work
just like printer classes, but they are created automatically based
upon the available printers and classes on the network. This allows you
to setup multiple print servers with identical printer configurations
and have the client machines send their print jobs to the first
available server. If one or more servers go down, the jobs are
automatically redirected to the servers that are running, providing
fail-safe printing.
Run the lpadmin command with the -p and
-c options to add a printer to a class:
/usr/sbin/lpadmin -p printer -c class ENTER
The class is created automatically if it doesn't exist. To
remove a printer from a class use the -r option:
/usr/sbin/lpadmin -p printer -r class ENTER
To remove the entire class just use the -x option:
/usr/sbin/lpadmin -x class ENTER
The Web interface is located at:
http://localhost:631/admin
The Add Class and Modify Class interfaces
provide a list of available printers; click on the printers of interest
to add them to the class.
A noted earlier, implicit classes are created automatically from the
available network printers and classes. To disable this functionality,
set the ImplicitClasses
directive to Off in the cupsd.conf file. You
will find more information on doing this in
Chapter 6, "Printing System Management".
This chapter discusses several ways to configure CUPS clients for
printing.
A client is any machine that sends print jobs to another machine for
final printing. Clients can also be servers if they communicate
directly with any printers of their own.
CUPS supports several methods of configuring client machines:
The most tedious method of configuring client machines is to
configure each remote queue by hand using the lpadmin
command:
lpadmin -p printer -E -v ipp://server/printers/printer ENTER
The printer name is the name of the printer on the
server machine. The server name is the hostname or IP
address of the server machine. Repeat the lpadmin command
for each remote printer you wish to use.
| NOTE:
Manual configuration of print queues is not recommended for large
numbers of client machines because of the administration nightmare it
creates. For busy networks, consider subnetting groups of clients and
polling and relaying printer information instead.
|
CUPS can be configured to run without a local spooler and send all
jobs to a single server. However, if that server goes down then all
printing will be disabled. Use this configuration only as absolutely
needed.
The default server is normally "localhost". To override the default
server create a file named /etc/cups/client.conf and add a
line reading:
ServerName server
to the file. The server name can be the hostname or IP
address of the default server.
The default server can also be customized on a per-user basis. To set
a user-specific server create a file named ~/.cupsrc and add
a line reading:
ServerName server
to the file. The server name can be the hostname or IP
address of the default server.
CUPS supports automatic client configuration of printers on the same
subnet. To configure printers on the same subnet, do nothing.
Each client should see the available printers within 30 seconds
automatically. The printer and class lists are updated automatically as
printers and servers are added or removed.
If you want to see printers on other subnets as well, use the
BrowsePoll directive as described next.
| NOTE:
The BrowseAddress directive
enables broadcast traffic from your server. The default configuration
braodcasts printer information every 30 seconds. Although this printer
information does not use much bandwidth, typically about 80 bytes per
printer, it can add up with large numbers of servers and printers.
Use the BrowseInterval and
BrowseTimeout directives to
tune the amount of data that is added to your network load. In
addition, subnets can be used to minimize the amount of traffic that is
carried by the "backbone" of your large network.
|
If you have CUPS servers on different subnets, then you should
configure CUPS to poll those servers. Polling provides the benefits of
automatic configuration without significant configuration on the
clients, and multiple clients on the same subnet can share the same
configuration information.
Polling is enabled by specifying one or more
BrowsePoll directives in the /etc/cups/cupsd.conf
file. For information on making these changes, see
Chapter 6, "Printing System Management".
Multiple BrowsePoll lines can
be used to poll multiple CUPS servers. To limit the amount of polling
you do from client machines, you can have only one of the clients do
the polling and relay that information to the others on the same subnet
(described next).
When you have clients and servers spread across multiple subnets, the
polling method is inefficient. CUPS provides a
BrowseRelay directive that enables a single client to relay
(broadcast) the polled printer information to the local subnet.
For example, Server A and Server B are on subnet 1 and subnet 2,
while the clients are on subnet 3. To provide printers to all of the
clients in subnet 3, client C will be configured with the following
directives in /etc/cups/cupsd.conf:
# Poll the two servers
BrowsePoll ServerA
BrowsePoll ServerB
# Relay the printers to the local subnet
BrowseRelay 127.0.0.1 192.168.3.255
The BrowseRelay line
specifies a source address and mask. Any browse packets coming from a
matching address wil be sent to the given broadcast address. In this
case, we want the packets from the local machine (127.0.0.1) relayed to
the other clients.
As printers are found using polling, they are relayed from client C
to the rest of the clients through a broadcast on subnet 3. The rest of
the clients can use the standard cupsd.conf configuration.
The BrowseRelay directive can
also be used to relay browsing packets from one network interface to
another. For example, if client C in the previous example had network
interfaces attaches to both subnet 1 and subnet 2, it could use the
BrowseRelay directive exclusively:
# Relay the printers from subnet 1 and 2 to subnet 3
BrowseRelay 192.168.1 192.168.3.255
BrowseRelay 192.168.2 192.168.3.255
When using server polling or broadcasting, CUPS clients can
automatically merge identical printers on multiple servers into a
single implicit class queue. Clients assume that printers with
the same name on multiple servers are in fact the same printer or type
of printer being served by multiple machines.
If you have two printers, LaserJet@ServerA and LaserJet@ServerB, a
third implicit class called LaserJet will be created
automatically on the client that refers to both printers. If the client
also has a local printer with the name LaserJet and the
ImplicitAnyClasses directive is enabled, then an
implicit class named AnyLaserJet will be created instead.
Otherwise, the local printer will prevent the creation of an implicit
class, since CUPS will assume that the local printer will always be
more available than a remote one.
The client will alternate between servers and automatically stop
sending jobs to a server if it goes down, providing a load-balancing
effect and fail-safe operation with automatic switchover.
This chapter shows how you can configure the CUPS server.
Several text files are used to configure CUPS. All of the server
configuration files are located in the /etc/cups directory:
- classes.conf
- This file contains information on each printer class. Normally you
manipulate this file using the
lpadmin command or the Web
interface.
- client.conf
- This file provides the default server name for client machines. See Chapter 5, "Client Setup" for more information.
- cupsd.conf
- This file controls how the CUPS server (/usr/sbin/cupsd)
operates and is normally edited by hand.
- mime.convs
- This file contains a list of standard file conversion filters and
their costs. You normally do not edit this file.
- mime.types
- This file contains a list of standard file formats and how to
recognize them. You normally do not edit this file.
- printers.conf
- This file contains information on each printer. Normally you
manipulate this file using the
lpadmin command or the Web
Interface.
Once you have made a change to a configuration file you need to
restart the CUPS server by sending it a HUP signal or
using the supplied initialization script. The CUPS distributions
install the script in the init.d directory with the name
cups. The location varies based upon the operating system:
/etc/software/init.d/cups restart ENTER
/etc/rc.d/init.d/cups restart ENTER
/etc/init.d/cups restart ENTER
/sbin/init.d/cups restart ENTER
The /etc/cups/cupsd.conf file contains configuration
directives that control how the server functions. Each directive is
listed on a line by itself followed by its value. Comments are
introduced using the number sign ("#") character at the beginning of a
line. Since the server configuration file consists of plain text, you
can use your favorite text editor to make changes to it.
The cupsd.conf file contains many directives that
determine how the server operates:
Examples
AccessLog /var/log/cups/access_log
AccessLog /var/log/cups/access_log-%s
AccessLog syslog
Description
The AccessLog directive sets the name of the access log
file. If the filename is not absolute then it is assumed to be relative
to the ServerRoot directory. The
access log file is stored in "common log format" and can be used by any
web access reporting tool to generate a report on CUPS server activity.
The server name can be included in the filename by using %s
in the name.
The special name "syslog" can be used to send the access information
to the system log instead of a plain file.
The default access log file is /var/log/cups/access_log.
Examples
Allow from All
Allow from None
Allow from *.domain.com
Allow from .domain.com
Allow from host.domain.com
Allow from nnn.*
Allow from nnn.nnn.*
Allow from nnn.nnn.nnn.*
Allow from nnn.nnn.nnn.nnn
Allow from nnn.nnn.nnn.nnn/mm
Allow from nnn.nnn.nnn.nnn/mmm.mmm.mmm.mmm
Allow from @LOCAL
Allow from @IF(name)
Description
The Allow directive specifies a hostname, IP address, or
network that is allowed access to the server. Allow
directives are cummulative, so multiple Allow directives
can be used to allow access for multiple hosts or networks. The
/mm notation specifies a CIDR netmask:
| mm | netmask |
mm | netmask |
|---|
| 0 | 0.0.0.0 |
8 | 255.0.0.0 |
| 1 | 128.0.0.0 |
16 | 255.255.0.0 |
| 2 | 192.0.0.0 |
24 | 255.255.255.0 |
| ... | ... |
32 | 255.255.255.255 |
The @LOCAL name will allow access from all local network
interfaces, but not remote point-to-point interfaces. The
@IF(name) name will allow access from the named interface.
The Allow directive must appear inside a
Location directive.
Examples
AuthClass Anonymous
AuthClass User
AuthClass System
AuthClass Group
Description
The AuthClass directive defines what level of
authentication is required:
Anonymous - No authentication should be performed
(default.)User - A valid username and password is required.System - A valid username and password is required, and
the username must belong to the "sys" group; this can be changed using
the SystemGroup directive.Group - A valid username and password is required, and
the username must belong to the group named by the AuthGroupName
directive.
The AuthClass directive must appear inside a
Location directive.
Examples
AuthGroupName mygroup
AuthGroupName lp
Description
The AuthGroupName directive sets the group to use for
Group authentication.
The AuthGroupName directive must appear inside a
Location directive.
Examples
AuthType None
AuthType Basic
AuthType Digest
AuthType BasicDigest
Description
The AuthType directive defines the type of
authentication to perform:
None - No authentication should be performed (default.)Basic - Basic authentication should be performed using
the UNIX password and group files.Digest - Digest authentication should be performed
using the /etc/cups/passwd.md5 file.BasicDigest - Basic authentication should be performed
using the /etc/cups/passwd.md5 file.
When using Basic, Digest, or
BasicDigest authentication, clients connecting through the
localhost interface can also authenticate using
certificates.
The AuthType directive must appear inside a
Location directive.
Examples
AutoPurgeJobs Yes
AutoPurgeJobs No
Description
The AutoPurgeJobs directive specifies whether or not to
purge completed jobs once they are no longer required for quotas. This
option has no effect if quotas are not enabled. The default setting is
No.
Examples
BrowseAddress 255.255.255.255:631
BrowseAddress 192.0.2.255:631
BrowseAddress host.domain.com:631
BrowseAddress @LOCAL
BrowseAddress @IF(name)
Description
The BrowseAddress directive specifies an address to send
browsing information to. Multiple BrowseAddress directives
can be specified to send browsing information to different networks or
systems.
The @LOCAL name will broadcast printer information to
all local interfaces. The @IF(name) name will broadcast to
the named interface.
No browse addresses are set by default.
| NOTE:
If you are using HP-UX 10.20 and a subnet that is not 24, 16, or 8
bits, printer browsing (and in fact all broadcast reception) will not
work. This problem appears to be fixed in HP-UX 11.0.
|
Examples
BrowseAllow from all
BrowseAllow from none
BrowseAllow from 192.0.2
BrowseAllow from 192.0.2.0/24
BrowseAllow from 192.0.2.0/255.255.255.0
BrowseAllow from *.domain.com
BrowseAllow from @LOCAL
BrowseAllow from @IF(name)
Description
The BrowseAllow directive specifies a system or network
to accept browse packets from. The default is to accept browse packets
from all hosts.
Host and domain name matching require that you enable the
HostNameLookups directive.
IP address matching supports exact matches, partial addresses that
match networks using netmasks of 255.0.0.0, 255.255.0.0, and
255.255.255.0, or network addresses using the specified netmask or bit
count.
The @LOCAL name will allow browse data from all local
network interfaces, but not remote point-to-point interfaces. The
@IF(name) name will allow browse data from the named interface.
Examples
BrowseDeny from all
BrowseDeny from none
BrowseDeny from 192.0.2
BrowseDeny from 192.0.2.0/24
BrowseDeny from 192.0.2.0/255.255.255.0
BrowseDeny from *.domain.com
BrowseDeny from @LOCAL
BrowseDeny from @IF(name)
Description
The BrowseDeny directive specifies a system or network
to reject browse packets from. The default is to deny browse packets
from no hosts.
Host and domain name matching require that you enable the
HostNameLookups directive.
IP address matching supports exact matches, partial addresses that
match networks using netmasks of 255.0.0.0, 255.255.0.0, and
255.255.255.0, or network addresses using the specified netmask or bit
count.
The @LOCAL name will block browse data from all local
network interfaces, but not remote point-to-point interfaces. The
@IF(name) name will block browse data from the named interface.
Examples
BrowseInterval 0
BrowseInterval 30
Description
The BrowseInterval directive specifies the maximum
amount of time between browsing updates. Specifying a value of 0
seconds disables outgoing browse updates but allows a server to receive
printer information from other hosts.
The BrowseInterval value should always be less than the BrowseTimeout value. Otherwise
printers and classes will disappear from client systems between
updates.
Examples
BrowseOrder allow,deny
BrowseOrder deny,allow
Description
The BrowseOrder directive specifies the order of
allow/deny processing. The default order is deny,allow:
allow,deny - Browse packets are accepted unless
specifically denied.deny,allow - Browse packets are rejected unless
specifically allowed.
Examples
BrowsePoll 192.0.2.2:631
BrowsePoll host.domain.com:631
Description
The BrowsePoll directive polls a server for available
printers once every BrowseInterval
seconds. Multiple BrowsePoll directives can be
specified to poll multiple servers.
If BrowseInterval is set to 0 then the server is polled
once every 30 seconds.
Examples
BrowsePort 631
BrowsePort 9999
Description
The BrowsePort directive specifies the UDP port number
used for browse packets. The default port number is 631.
| NOTE:
You must set the BrowsePort to the same value on all of
the systems that you want to see.
|
Examples
BrowseProtocols CUPS
BrowseProtocols SLP
BrowseProtocols CUPS SLP
BrowseProtocols all
Description
The BrowseProtocols directive specifies the protocols to
use when collecting and distributing shared printers on the local
network. The default protocol is CUPS, which is a
broadcast-based protocol.
| NOTE:
When using the SLP protocol, you must have at least one
Directory Agent (DA) server on your network. Otherwise the CUPS
scheduler (cupsd) will not respond to client requests for
several seconds while polling the network.
|
Examples
BrowseRelay 193.0.2.1 192.0.2.255
BrowseRelay 193.0.2.0/255.255.255.0 192.0.2.255
BrowseRelay 193.0.2.0/24 192.0.2.255
BrowseRelay *.domain.com 192.0.2.255
BrowseRelay host.domain.com 192.0.2.255
Description
The BrowseRelay directive specifies source and
destination addresses for relaying browsing information from one host
or network to another. Multiple BrowseRelay directives can
be specified as needed.
BrowseRelay is typically used on systems that bridge
multiple subnets using one or more network interfaces. It can also be
used to relay printer information from polled servers with the line:
BrowseRelay 127.0.0.1 255.255.255.255
This effectively provides access to printers on a WAN for all clients
on the LAN(s).
Examples
BrowseShortNames Yes
BrowseShortNames No
Description
The BrowseShortNames directive specifies whether or not
short names are used for remote printers when possible. Short names are
just the remote printer name, without the server ("printer"). If more
than one remote printer is detected with the same name, the printers
will have long names ("printer@server1", "printer@server2".)
The default value for this option is Yes.
Examples
BrowseTimeout 300
BrowseTimeout 60
Description
The BrowseTimeout directive sets the timeout for printer
or class information that is received in browse packets. Once a printer
or class times out it is removed from the list of available
destinations.
The BrowseTimeout value should always be greater than
the BrowseInterval value.
Otherwise printers and classes will disappear from client systems
between updates.
Examples
Browsing On
Browsing Off
Description
The Browsing directive controls whether or not network
printer browsing is enabled. The default setting is On.
| NOTE:
If you are using HP-UX 10.20 and a subnet that is not 24, 16, or 8
bits, printer browsing (and in fact all broadcast reception) will not
work. This problem appears to be fixed in HP-UX 11.0.
|
Examples
Classification
Classification classified
Classification confidential
Classification secret
Classification topsecret
Classification unclassified
Description
The Classification directive sets the classification
level on the server. When this option is set, at least one of the
banner pages is forced to the classification level, and the
classification is placed on each page of output. The default is no
classification level.
Examples
ClassifyOverride Yes
ClassifyOverride No
Description
The ClassifyOverride directive specifies whether users
can override the default classification level on the server. When the
server classification is set, users can change the classification using
the job-sheets option and can choose to only print one
security banner before or after the job. If the job-sheets
option is set to none then the server default
classification is used.
The default is to not allow classification overrides.
Examples
ConfigFilePerm 0644
ConfigFilePerm 0600
Description
The ConfigFilePerm directive specifies the permissions
to use when writing configuration files. The default is 0600.
Examples
DataDir /usr/share/cups
Description
The DataDir directive sets the directory to use for data
files.
Examples
DefaultCharset utf-8
DefaultCharset iso-8859-1
DefaultCharset windows-1251
Description
The DefaultCharset directive sets the default character
set to use for client connections. The default character set is
utf-8 but is overridden by the character set for the language
specified by the client or the DefaultLanguage directive.
Examples
DefaultLanguage de
DefaultLanguage en
DefaultLanguage es
DefaultLanguage fr
DefaultLanguage it
Description
The DefaultLanguage directive specifies the default
language to use for client connections. Setting the default language
also sets the default character set if a language localization file
exists for it. The default language is "en" for English.
Examples
Deny from All
Deny from None
Deny from *.domain.com
Deny from .domain.com
Deny from host.domain.com
Deny from nnn.*
Deny from nnn.nnn.*
Deny from nnn.nnn.nnn.*
Deny from nnn.nnn.nnn.nnn
Deny from nnn.nnn.nnn.nnn/mm
Deny from nnn.nnn.nnn.nnn/mmm.mmm.mmm.mmm
Deny from @LOCAL
Deny from @IF(name)
Description
The Deny directive specifies a hostname, IP address, or
network that is allowed access to the server. Deny
directives are cummulative, so multiple Deny directives
can be used to allow access for multiple hosts or networks. The
/mm notation specifies a CIDR netmask:
| mm | netmask |
mm | netmask |
|---|
| 0 | 0.0.0.0 |
8 | 255.0.0.0 |
| 1 | 128.0.0.0 |
16 | 255.255.0.0 |
| 2 | 192.0.0.0 |
24 | 255.255.255.0 |
| ... | ... |
32 | 255.255.255.255 |
The @LOCAL name will deny access from all local network
interfaces, but not remote point-to-point interfaces. The
@IF(name) name will deny access from the named interface.
The Deny directive must appear inside a
Location directive.
Examples
DocumentRoot /usr/share/doc/cups
DocumentRoot /foo/bar/doc/cups
Description
The DocumentRoot directive specifies the location of web
content for the HTTP server in CUPS. If an absolute path is not
specified then it is assumed to be relative to the
ServerRoot directory. The default directory is
/usr/share/doc/cups.
Documents are first looked up in a sub-directory for the primary
language requested by the client (e.g. /usr/share/doc/cups/fr/...
) and then directly under the DocumentRoot directory (e.g.
/usr/share/doc/cups/...), so it is possible to localize the web
content by providing subdirectories for each language needed.
Examples
Encryption Never
Encryption IfRequested
Encryption Required
Description
The Encryption directive must appear instead a
Location section and specifies the encryption settings
for that location. The default setting is IfRequested for
all locations.
Examples
ErrorLog /var/log/cups/error_log
ErrorLog /var/log/cups/error_log-%s
ErrorLog syslog
Description
The ErrorLog directive sets the name of the error log
file. If the filename is not absolute then it is assumed to be relative
to the ServerRoot directory. The
default error log file is /var/log/cups/error_log.
The server name can be included in the filename by using %s
in the name.
The special name "syslog" can be used to send the error information
to the system log instead of a plain file.
Examples
FaxRetryInterval 300
FaxRetryInterval 30
Description
The FaxRetryInterval directive determines how often fax
print jobs are retried when the backend is unable to send the fax. The
value is the number of seconds between tries.
The default setting is 300 seconds.
Examples
FaxRetryLimit 5
FaxRetryLimit 100
Description
The FaxRetryLimit directive determines how many times a
fax job is retried before it is canceled.
The default setting is 5.
Examples
FileDevice Yes
FileDevice No
Description
The FileDevice directive determines whether the
scheduler allows new printers to be added using device URIs of the form
file:/filename. File devices are most often used to test
new printer drivers and do no support raw file printing.
The default setting is No.
| Note:
File devices are managed by the scheduler. Since the scheduler
normally runs as the root user, file devices can be used to overwrite
system files and potentially gain unauthorized access to the system. If
you must create printers using file devices, we recommend that you set
the FileDevice directive to Yes for only as
long as you need to add the printers to the system, and then reset the
directive to No.
|
Examples
FilterLimit 0
FilterLimit 200
FilterLimit 1000
Description
The FilterLimit directive sets the maximum cost of all
running job filters. It can be used to limit the number of filter
programs that are run on a server to minimize disk, memory, and CPU
resource problems. A limit of 0 disables filter limiting.
An average print to a non-PostScript printer needs a filter limit of
about 200. A PostScript printer needs about half that (100). Setting
the limit below these thresholds will effectively limit the scheduler
to printing a single job at any time.
The default limit is 0.
Examples
FilterNice 0
FilterNice 39
FilterNice -10
Description
The FilterNice directive sets the scheduling priority of
job filters. Values larger than 0 give filters a lower priority while
values smaller than 0 give filters a higher priority. The
FilterNice value does not affect the priority of job backends.
The default priority is 0.
Examples
FontPath /foo/bar/fonts
FontPath /usr/share/cups/fonts:/foo/bar/fonts
Description
The FontPath directive specifies the font path to use
when searching for fonts. The default font path is
/usr/share/cups/fonts.
Examples
Group sys
Group system
Group root
Description
The Group directive specifies the UNIX group that filter
and CGI programs run as. The default group is sys,
system, or root depending on the operating system.
Examples
HideImplicitMembers Yes
HideImplicitMembers No
Description
The HideImplicitMembers directive controls whether the
individual printers in an implicit class are shown to the user. The
default is No.
ImplicitClasses must be
enabled for this directive to have any effect.
Examples
HostNameLookups On
HostNameLookups Off
HostNameLookups Double
Description
The HostNameLookups directive controls whether or not
CUPS looks up the hostname for connecting clients. The Double
setting causes CUPS to verify that the hostname resolved from the
address matches one of the addresses returned for that hostname.
Double lookups also prevent clients with unregistered addresses
from connecting to your server. The default is Off to
avoid the potential server performance problems with hostname lookups.
Set this option to On or Double only if
absolutely required.
Examples
ImplicitAnyClasses On
ImplicitAnyClasses Off
Description
The ImplicitAnyClasses directive controls whether
implicit classes for local and remote printers are created with the
name AnyPrinter. The default setting is Off.
ImplicitClasses must be
enabled for this directive to have any effect.
Examples
ImplicitClasses On
ImplicitClasses Off
Description
The ImplicitClasses directive controls whether implicit
classes are created based upon the available network printers and
classes. The default setting is On but is automatically
turned Off if Browsing
is turned Off.
Examples
Include filename
Include /foo/bar/filename
Description
The Include directive includes the named file in the
cupsd.conf file. If no leading path is provided, the file is
assumed to be relative to the ServerRoot
directory.
Examples
KeepAlive On
KeepAlive Off
Description
The KeepAlive directive controls whether or not to
support persistent HTTP connections. The default is On.
HTTP/1.1 clients automatically support persistent connections, while
HTTP/1.0 clients must specifically request them using the
Keep-Alive attribute in the Connection: field of
each request.
Examples
KeepAliveTimeout 60
KeepAliveTimeout 30
Description
The KeepAliveTimeout directive controls how long a
persistent HTTP connection will remain open after the last request. The
default is 60 seconds.
Examples
<Limit GET POST>
...
</Limit>
<Limit ALL>
...
</Limit>
Description
The Limit directive groups access control directives for
specific types of HTTP requests and must appear inside a
Location section. Access can be limited for individual
request types (DELETE, GET, HEAD
, OPTIONS, POST, PUT, and
TRACE) or for all request types (ALL). The request
type names are case-sensitive for compatibility with Apache.
Examples
<LimitExcept GET POST>
...
</LimitExcept>
Description
The LimitExcept directive groups access control
directives for specific types of HTTP requests and must appear inside a
Location section. Unlike the
Limit directive, LimitExcept restricts
access for all requests except those listed on the
LimitExcept line.
Examples
LimitRequestBody 10485760
LimitRequestBody 10m
LimitRequestBody 0
Description
The LimitRequestBody directive controls the maximum size
of print files, IPP requests, and HTML form data in HTTP POST requests.
The default limit is 0 which disables the limit check.
Also see the identical MaxRequestSize
directive.
Examples
Listen 127.0.0.1:631
Listen 192.0.2.1:631
Description
The Listen directive specifies a network address and
port to listen for connections. Multiple Listen directives
can be provided to listen on multiple addresses.
The Listen directive is similar to the
Port directive but allows you to restrict access to specific
interfaces or networks.
Examples
<Location />
...
</Location>
<Location /admin>
...
</Location>
<Location /printers>
...
</Location>
<Location /printers/name>
...
</Location>
<Location /classes>
...
</Location>
<Location /classes/name>
...
</Location>
Description
The Location directive specifies access control and
authentication options for the specified HTTP resource or path. The
Allow, AuthClass,
AuthGroupName,
AuthType, Deny,
Encryption, Limit,
LimitExcept, Order, Require, and
Satisfy directives may all appear inside a location.
Locations on the Server.
| Location | Description |
|---|
| / | The path for all get operations (get-printers,
get-jobs, etc.) |
| /admin | The path for all administration operations
(add-printer, delete-printer, start-printer, etc.) |
| /admin/conf | The path for access to the CUPS
configuration files (cupsd.conf, client.conf, etc.) |
| /classes | The path for all classes |
| /classes/name | The resource for class name |
| /jobs | The path for all jobs (hold-job, release-job,
etc.) |
| /jobs/id | The resource for job id |
| /printers | The path for all printers |
| /printers/name | The path for printer name |
| /printers/name.ppd | The PPD file path for printer
name |
Note that more specific resources override the less specific ones. So
the directives inside the /printers/name location will
override ones from /printers. Directives inside
/printers will override ones from /. None of the
directives are inherited. More information can be found in section
"Printing System Security".
Examples
LogFilePerm 0644
LogFilePerm 0600
Description
The LogFilePerm directive specifies the permissions to
use when writing configuration files. The default is 0644.
Examples
LogLevel none
LogLevel emerg
LogLevel alert
LogLevel crit
LogLevel error
LogLevel warn
LogLevel notice
LogLevel info
LogLevel debug
LogLevel debug2
Description
The LogLevel directive specifies the level of logging
for the ErrorLog file. The
following values are recognized (each level logs everything under the
preceding levels):
none - Log nothing.emerg - Log emergency conditions that prevent the
server from running.alert - Log alerts that must be handled immediately.crit - Log critical errors that don't prevent the
server from running.error - Log general errors.warn - Log errors and warnings.notice - Log temporary error conditions.info - Log all requests and state changes (default).debug - Log basic debugging information.debug2 - Log all debugging information.
Examples
MaxClients 100
MaxClients 1024
Description
The MaxClients directive controls the maximum number of
simultaneous clients that will be allowed by the server. The default is
100 clients.
| NOTE:
Since each print job requires a file descriptor for the status pipe,
the CUPS server internally limits the MaxClients value to
1/3 of the available file descriptors to avoid possible problems when
printing large numbers of jobs.
|
Examples
MaxClientsPerHost 0
MaxClientsPerHost 10
Description
The MaxClientsPerHost directive controls the maximum
number of simultaneous clients that will be allowed from a single host
by the server. The default is the MaxClients value. A
value of 0 uses the automatic setting based on the MaxClients
value.
This directive provides a small measure of protection against Denial
of Service attacks from a single host.
Examples
MaxCopies 100
MaxCopies 65535
Description
The MaxCopies directive controls the maximum number of
copies that a user can print of a job. The default is 100 copies.
| NOTE:
Most HP PCL laser printers internally limit the number of copies to
100.
|
Examples
MaxJobs 100
MaxJobs 9999
MaxJobs 0
Description
The MaxJobs 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 500.
Examples
MaxJobsPerPrinter 100
MaxJobsPerPrinter 9999
MaxJobsPerPrinter 0
Description
The MaxJobsPerPrinter directive controls the maximum
number of active jobs that are allowed for each printer or class. Once
a printer or class reaches the limit, new jobs will be rejected until
one of the active jobs is completed, stopped, aborted, or cancelled.
Setting the maximum to 0 disables this functionality. The default
setting is 0.
Examples
MaxJobsPerUser 100
MaxJobsPerUser 9999
MaxJobsPerUser 0
Description
The MaxJobsPerUser directive controls the maximum number
of active jobs that are allowed for each user. Once a user reaches the
limit, new jobs will be rejected until one of the active jobs is
completed, stopped, aborted, or cancelled.
Setting the maximum to 0 disables this functionality. The default
setting is 0.
Examples
MaxLogSize 1048576
MaxLogSize 1m
MaxLogSize 0
Description
The MaxLogSize directive controls the maximum size of
each log file. Once a log file reaches or exceeds the maximum size it
is closed and renamed to filename.O. This allows you to
rotate the logs automatically. The default size is 1048576 bytes (1MB).
Setting the maximum size to 0 disables log rotation.
Examples
MaxRequestSize 10485760
MaxRequestSize 10m
MaxRequestSize 0
Description
The MaxRequestSize directive controls the maximum size
of print files, IPP requests, and HTML form data in HTTP POST requests.
The default limit is 0 which disables the limit check.
Also see the identical
LimitRequestBody directive.
Examples
Order Allow,Deny
Order Deny,Allow
Description
The Order directive defines the default access control.
The following values are supported:
Allow,Deny - Allow requests from all systems except
for those listed in a Deny directive.Deny,Allow - Allow requests only from those listed in
an Allow directive.
The Order directive must appear inside a
Location directive.
Examples
PageLog /var/log/cups/page_log
PageLog /var/log/cups/page_log-%s
PageLog syslog
Description
The PageLog directive sets the name of the page log
file. If the filename is not absolute then it is assumed to be relative
to the ServerRoot directory. The
default page log file is /var/log/cups/page_log.
The server name can be included in the filename by using %s
in the name.
The special name "syslog" can be used to send the page information to
the system log instead of a plain file.
Examples
Port 631
Port 80
Description
The Port directive specifies a port to listen on.
Multiple Port lines can be specified to listen on multiple
ports. The Port directive is equivalent to "Listen
*:nnn". The default port is 631.
Examples
PreserveJobFiles On
PreserveJobFiles Off
Description
The PreserveJobFiles directive controls whether the
document files of completed, cancelled, or aborted print jobs are
stored on disk.
A value of On preserves job files until the
administrator purges them with the cancel command. Jobs
can be restarted (and reprinted) as desired until they are purged.
A value of Off (the default) removes the job files as
soon as each job is completed, cancelled, or aborted.
Examples
PreserveJobHistory On
PreserveJobHistory Off
Description
The PreserveJobHistory directive controls whether the
history of completed, cancelled, or aborted print jobs is stored on
disk.
A value of On (the default) preserves job information
until the administrator purges it with the cancel command.
A value of Off removes the job information as soon as
each job is completed, cancelled, or aborted.
Examples
Printcap
Printcap /etc/printcap
Printcap /etc/printers.conf
Description
The Printcap directive controls whether or not a
printcap file is automatically generated and updated with a list of
available printers. If specified with no value, then no printcap file
will be generated. The default is to generate a file named
/etc/printcap.
When a filename is specified (e.g. /etc/printcap), the
printcap file is written whenever a printer is added or removed. The
printcap file can then be used by applications that are hardcoded to
look at the printcap file for the available printers.
Examples
PrintcapFormat BSD
PrintcapFormat Solaris
Description
The PrintcapFormat directive controls the output format
of the printcap file. The default is to generate a BSD printcap file.
Example
PrintcapGUI /usr/bin/glpoptions
Description
The PrintcapGUI directive sets the program to use when
displaying an option panel from an IRIX application that uses the
Impressario print API. The default program is the ESP Print Pro
"glpoptions" GUI.
The program must accept the -d option to specify a
printer and the -o option to specify one or more options.
After allowing the user to select/change options, the program must then
write the list of printing options without the -o to the
standard output.
Examples
ReloadTimeout 60
ReloadTimeout 3600
ReloadTimeout 0
Description
The ReloadTimeout directive sets how long the scheduler
waits for jobs to complete before reloading the server configuration.
The default timeout is 60 seconds.
Examples
RemoteRoot remroot
RemoteRoot root
Description
The RemoteRoot directive sets the username for
unauthenticated root requests from remote hosts. The default username
is remroot. Setting RemoteRoot to root
effectively disables this security mechanism.
Examples
RequestRoot /var/spool/cups
RequestRoot /foo/bar/spool/cups
Description
The RequestRoot directive sets the directory for
incoming IPP requests and HTML forms. If an absolute path is not
provided then it is assumed to be relative to the
ServerRoot directory. The default request directory is
/var/spool/cups.
Examples
Require group foo bar
Require user john mary
Require valid-user
Description
The Require directive specifies that authentication is
required for the resource. The group keyword specifies
that the authenticated user must be a member of one or more of the
named groups that follow.
The user keyword specifies that the authenticated user
must be one of the named users that follow.
The valid-user keyword specifies that any authenticated
user may access the resource.
The default is to do no authentication. This directive must appear
inside a Location directive.
Examples
RIPCache 8m
RIPCache 1g
RIPCache 2048k
Description
The RIPCache directive sets the size of the memory cache
used by Raster Image Processor ("RIP") filters such as
imagetoraster and pstoraster. The size can be
suffixed with a "k" for kilobytes, "m" for megabytes, or "g" for
gigabytes. The default cache size is "8m", or 8 megabytes.
Examples
RootCertDuration 300
RootCertDuration 0
Description
The RootCertDuration directive controls the interval
between updates of the root authentication certificate. The default is
300 seconds which updates the root certificate approximately once
every 5 minutes. Set the interval to 0 to disable certificate updates
entirely.
Examples
RunAsUser Yes
RunAsUser No
Description
The RunAsUser directive controls whether the scheduler
runs as the unpriviledged user account (usually lp). The
default is No which leaves the scheduler running as the
root user.
Note: Running as a non-priviledged user may prevent LPD and
locally connected printers from working due to permission problems. The
lpd backend will automatically use a non-priviledged mode
that is not 100% compliant with RFC 1179. The parallel,
serial, and usb backends will need write access to
the corresponding device files.
Examples
Satisfy all
Satisfy any
Description
The Satisfy directive specifies whether all conditions
must be satisfied to allow access to the resource. If set to all
, then all authentication and access control conditions must be satified
to allow access.
Setting Satisfy to any allows a user to
gain access if the authentication or access control requirements are
satisfied. For example, you might require authentication for remote
access, but allow local access without authentication.
The default is all. This directive must appear inside a Location directive.
Examples
ServerAdmin user@host
ServerAdmin root@foo.bar.com
Description
The ServerAdmin directive identifies the email address
for the administrator on the system. By default the administrator email
address is root@server, where server is the
server name.
Examples
ServerBin /usr/lib/cups
ServerBin /foo/bar/lib/cups
Description
The ServerBin directive sets the directory for
server-run executables. If an absolute path is not provided then it is
assumed to be relative to the ServerRoot
directory. The default executable directory is /usr/lib/cups
.
Examples
ServerCertificate /etc/cups/ssl/server.crt
Description
The ServerCertificate directive specifies the location
of the SSL certificate file used by the server when negotiating
encrypted connections. The certificate must not be encrypted (password
protected) since the scheduler normally runs in the background and will
be unable to ask for a password. The default certificate file is
/etc/cups/ssl/server.crt.
Examples
ServerKey /etc/cups/ssl/server.key
Description
The ServerKey directive specifies the location of the
SSL private key file used by the server when negotiating encrypted
connections. The default key file is /etc/cups/ssl/server.crt
.
ServerName
Examples
ServerName foo.domain.com
ServerName myserver.domain.com
Description
The ServerName directive specifies the hostname that is
reported to clients. By default the server name is the hostname.
Examples
ServerRoot /etc/cups
ServerRoot /foo/bar/cups
Description
The ServerRoot directive specifies the absolute path to
the server configuration and state files. It is also used to resolve
relative paths in the cupsd.conf file. The default server
directory is /etc/cups.
Examples
ServerTokens None
ServerTokens ProductOnly
ServerTokens Major
ServerTokens Minor
ServerTokens Minimal
ServerTokens OS
ServerTokens Full
Description
The ServerTokens directive specifies the information
that is included in the Server header of HTTP responses. The default
value is Minor which generates "CUPS/1.1".
Examples
SSLListen 127.0.0.1:443
SSLListen 192.0.2.1:443
Description
The SSLListen directive specifies a network address and
port to listen for secure connections. Multiple SSLListen
directives can be provided to listen on multiple addresses.
The SSLListen directive is similar to the
SSLPort directive but allows you to restrict access to
specific interfaces or networks.
Examples
SSLPort 443
Description
The SSLPort directive specifies a port to listen on for
secure connections. Multiple SSLPort lines can be
specified to listen on multiple ports.
Examples
SystemGroup sys
SystemGroup system
SystemGroup root
Description
The SystemGroup directive specifies the system
administration group for System authentication. More
information can be found later in this chapter in
"Printing System Security".
Examples
TempDir /var/tmp
TempDir /foo/bar/tmp
Description
The TempDir directive specifies an absolute path for the
directory to use for temporary files. The default directory is
/var/tmp.
Temporary directories must be world-writable and should have the
"sticky" permission bit enabled so that other users cannot delete
filter temporary files. The following commands will create an
appropriate temporary directory called /foo/bar/tmp:
mkdir /foo/bar/tmp ENTER
chmod a+rwxt /foo/bar/tmp ENTER
Examples
Timeout 300
Timeout 90
Description
The Timeout directive controls the amount of time to
wait before an active HTTP or IPP request times out. The default
timeout is 300 seconds.
Examples
User lp
User guest
Description
The User directive specifies the UNIX user that filter
and CGI programs run as. The default user is lp.
The CUPS client application (lp, lpr, and
so forth) use the /etc/cups/client.conf file for default
settings. The client application also look in the user's home directory
for a file called .cupsrc. Each directive is listed on a
line by itself followed by its value. Comments are introduced using the
number sign ("#") character at the beginning of a line.
Since the client configuration file consists of plain text, you can
use your favorite text editor to make changes to it.
The client.conf file contains two directives that
determine how the client behaves:
Examples
Encryption Never
Encryption IfRequested
Encryption Required
Encryption Always
Description
The Encryption directive specifies the default
encryption settings for the client. The default setting is
IfRequested.
Examples
ServerName foo.bar.com
ServerName 11.22.33.44
Description
The ServerName directive specifies sets the remote
server that is to be used for all client operations. That is, it
redirects all client requests to the remote server. The default is to
use the local server ("localhost").
The CUPS scheduler (cupsd) uses the /etc/cups/printers.conf
file to store the list of available printers. This file contains only
locally defined printers, but not remote printers that are created
automatically. Each directive is listed on a line by itself followed by
its value. Comments are introduced using the number sign ("#")
character at the beginning of a line.
Since the printer configuration file consists of plain text, you can
use your favorite text editor to make changes to it.
The printers.conf file contains many directives that
determine how the printer behaves:
Examples
Accepting yes
Accepting no
Description
The Accepting directive defines the initial Boolean
value for the printer-is-accepting-job attribute which can
be set by the accept and reject commands.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
AllowUser foo_user
AllowUser bar_user
Description
The AllowUser directive adds a username to the
requesting-user-name-allowed attribute which can be set by the
lpadmin -u command.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
<DefaultPrinter name/>
...
</Printer>
Description
The DefaultPrinter directive begins a printer definition
for the default server destination. It can be added by the
lpadmin command or if already defined, set as default by the
lpoptions -d command.
Examples
DenyUser foo_user
DenyUser bar_user
Description
The DenyUser directive adds a username to the
requesting-user-name-allowed attribute which can be set by the
lpadmin -u command.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
DeviceURI socket://foo.bar.com:9100
Description
The DeviceURI directive defines the value of the
device-uri-attribute attribute which can be set by the
lpadmin -v command.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
Info My Printer
Description
The Info directive defines the string for the
printer-info attribute which can be set by the lpadmin -D
command.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
JobSheets none,standard
Description
The JobSheets directive specifies the default banner
pages to print before and after a print job. In the above example, only
a standard banner will print after each job.
The lpoptions -o job-sheets= command can be used to set
banners. For example, the following command would produce the same
results of a standard banner at the end of each print job
for the default printer.
lpoptions -o job-sheets=none,standard
If only one banner file is specified, it will be printed before the
files in the job. If a second banner file is specified, it is printed
after the files in the job.
The available banner pages depend on the local system configuration;
CUPS includes the following banner files:
none - Do not produce a banner page.classified - A banner page with a "classified" label at
the top and bottom.confidential - A banner page with a "confidential"
label at the top and bottom.secret - A banner page with a "secret" label at the top
and bottom.standard - A banner page with no label at the top and
bottom.topsecret - A banner page with a "top secret" label at
the top and bottom.unclassified - A banner page with an "unclassified"
label at the top and bottom.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
KLimit 1234
Description
The KLimit directive defines the value of the
job-k-limit attribute which can be set by the lpadmin -o
job-k-limit= command.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
Location Building 3321
Description
The Location directive defines the string for the
printer-location attribute which can be set by the lpadmin
-L command.
| NOTE:
Do not confuse this Location directive with the one in
cupsd.conf. They are completely different.
|
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
PageLimit 1234
Description
The PageLimit directive defines the value of the
job-page-limit attribute which can be set by the lpadmin -o
job-page-limit= command.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
<Printer name/>
...
</Printer>
Description
The Printer directive begins a printer definition. It
can be added by the lpadmin command.
Examples
QuotaPeriod 604800
Description
The QuotaPeriod directive defines the value of the
job-quota-period attribute which can be set by the lpadmin
-o job-quota-period= command.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
State stopped
Description
The State directive defines the initial value of the
printer-state attribute. The strings idle and
stopped correspond to the IPP enumeration values.
This directive must appear inside a Printer
or DefaultPrinter
directive.
Examples
StateMessage Ready to print.
Description
The StateMessage directive defines the initial string
for the printer-state-message attribute. The following are
some example messages:
- Connected to host_name...
- Connecting to printer_queue on port port_number
...
- Network host host_name is busy; will retry in 30
seconds...
- Printer busy; will retry in 10 seconds...
- Printer is busy; retrying print job...
- Print file accepted - job ID id_number.
- Ready to print.
- Waiting for job to complete
This directive must appear inside a Printer
or DefaultPrinter
directive.
The CUPS scheduler (cupsd) uses the /etc/cups/classes.conf
file to store the list of available classes. This file contains only
locally defined classes, but not remote or implicit classes that are
created automatically. Each directive is listed on a line by itself
followed by its value. Comments are introduced using the number sign
("#") character at the beginning of a line.
Since the classes configuration file consists of plain text, you can
use your favorite text editor to make changes to it.
The classes.conf file contains many directives that
determine how the classes behaves:
Examples
Accepting yes
Accepting no
Description
The Accepting directive defines the initial Boolean
value for the printer-is-accepting-job attribute which can
be set by the accept and reject commands.
This directive must appear inside a Class
or DefaultClass directive.
Examples
AllowUser foo_user
AllowUser bar_user
Description
The AllowUser directive adds a username to the
requesting-user-name-allowed attribute which can be set by the
lpadmin -u command.
This directive must appear inside a Class
or DefaultClass directive.
Examples
<Class name/>
...
</Class>
Description
The Class directive begins a class definition. It can be
added by the lpadmin -c command.
Examples
<DefaultClass name/>
...
</DefaultClass>
Description
The DefaultClass directive begins a class definition for
the default server destination. It can be added by the lpadmin -c
command or if already defined, set as default by the lpoptions -d
command.
Examples
DenyUser foo_user
DenyUser bar_user
Description
The DenyUser directive adds a username to the
requesting-user-name-allowed attribute which can be set by the
lpadmin -u command.
This directive must appear inside a Class
or DefaultClass directive.
Examples
Info My Printer
Description
The Info directive defines the string for the
printer-info attribute which can be set by the lpadmin -D
command.
This directive must appear inside a Class
or DefaultClass directive.
Examples
JobSheets none,standard
Description
The JobSheets directive specifies the default banner
pages to print before and after a print job. In the above example, only
a standard banner will print after each job.
The lpoptions -o job-sheets= command can be used to set
banners. For example, the following command would produce the same
results of a standard banner at the end of each print job
for the default class.
lpoptions -o job-sheets=none,standard
If only one banner file is specified, it will be printed before the
files in the job. If a second banner file is specified, it is printed
after the files in the job.
The available banner pages depend on the local system configuration;
CUPS includes the following banner files:
none - Do not produce a banner page.classified - A banner page with a "classified" label at
the top and bottom.confidential - A banner page with a "confidential"
label at the top and bottom.secret - A banner page with a "secret" label at the top
and bottom.standard - A banner page with no label at the top and
bottom.topsecret - A banner page with a "top secret" label at
the top and bottom.unclassified - A banner page with an "unclassified"
label at the top and bottom.
This directive must appear inside a Class
or DefaultClass directive.
Examples
KLimit 1234
Description
The KLimit directive defines the value of the
job-k-limit attribute which can be set by the lpadmin -o
job-k-limit= command.
This directive must appear inside a Class
or DefaultClass directive.
Examples
Location Building 3321
Description
The Location directive defines the string for the
printer-location attribute which can be set by the lpadmin
-L command.
| NOTE:
Do not confuse this Location directive with the one in
cupsd.conf. They are completely different.
|
This directive must appear inside a Class
or DefaultClass directive.
Examples
PageLimit 1234
Description
The PageLimit directive defines the value of the
job-page-limit attribute which can be set by the lpadmin -o
job-page-limit= command.
This directive must appear inside a Class
or DefaultClass directive.
Examples
Printer foo
Printer bar
Printer foo@bar
Description
The Printer directive adds a printer to the class. It
can be added by the lpadmin -c command.
| NOTE:
Do not confuse this Printer directive with the one in
printers.conf. They are completely different.
|
This directive must appear inside a Class
or DefaultClass directive.
Examples
QuotaPeriod 604800
Description
The QuotaPeriod directive defines the value of the
job-quota-period attribute which can be set by the lpadmin
-o job-quota-period= command.
This directive must appear inside a Class
or DefaultClass directive.
Examples
State stopped
Description
The State directive defines the initial value of the
printer-state attribute. The strings idle and
stopped correspond to the IPP enumeration values.
This directive must appear inside a Class
or DefaultClass directive.
Examples
StateMessage Ready to print.
Description
The StateMessage directive defines the initial string
for the printer-state-message attribute. The following are
some example messages:
- Connected to host_name...
- Connecting to class_queue on port port_number
...
- Network host host_name is busy; will retry in 30
seconds...
- Printer busy; will retry in 10 seconds...
- Printer is busy; retrying print job...
- Print file accepted - job ID id_number.
- Ready to print.
- Waiting for job to complete
This directive must appear inside a Class
or DefaultClass directive.
CUPS provides support for address, certificate, and password (Basic
and Digest) based authentication and access control. Certificate and
password authentication provide ways to limit access to individual
people or groups.
Address based access control allows you to limit access to specific
systems, networks, or domains. While this does not provide
authentication, it does allow you to limit the potential users of your
system efficiently.
CUPS maintains a list of locations that have access control and/or
authentication enabled. Locations are specified using the
Location directive:
<Location /resource>
AuthClass ...
AuthGroupName ...
AuthType ...
Order ...
Allow from ...
Deny from ...
</Location>
Locations generally follow the directory structure of the
DocumentRoot directory, however CUPS does have several
virtual locations for administration, classes, jobs, and printers:
| Location | Description |
|---|
| /admin | The path for all administration operations. |
| /classes | The path for all classes. |
| /classes/name | The resource for class name. |
| /jobs | The path for all jobs. |
| /jobs/id | The resource for job id. |
| /printers | The path for all printers. |
| /printers/name | The path for printer name. |
| /printers/name.ppd | The PPD file path for printer
name. |
CUPS supports a local certificate-based authentication scheme that
can be used in place of Basic or Digest
authentication by clients connecting through the localhost
interface. Certificate authentication is not supported or allowed from
clients on any other interface.
Certificates are 128-bit random numbers that refer to an internal
authentication record in the server. A client connecting via the
localhost interface sends a request with an authorization header
of:
Authorization: Local 0123456789ABCDEF0123456789ABCDEF
The server then looks up the local certificate and authenticates
using the username associated with it.
Certificates are generated by the server automatically and stored in
the /etc/cups/certs directory using the process ID of the
CGI program started by the server. Certificate files are only readable
by the User and
Group defined in the cupsd.conf file. When the CGI
program ends the certificate is removed and invalidated automatically.
The special file /etc/cups/certs/0 defines the root
certificate which can be used by any client running as the
super-user or another user that is part of the group defined by the
SystemGroup directive. The root certificate is
automatically regenerated every 5 minutes.
Basic authentication uses UNIX users and passwords to authenticate
access to resources such as printers and classes, and to limit access
to administrative functions.
| NOTE:
Basic authentication sends the username and password Base64 encoded
from the client to the server, so it offers no protection against
eavesdropping. This means that a malicious user can monitor network
packets and discover valid users and passwords that could result in a
serious compromise in network security. Use Basic authentication with
extreme care.
|
The CUPS implementation of Basic authentication does not allow access
through user accounts without a password. If you try to authenticate
using an account without a password, your access will be immediately
blocked.
Once a valid username and password is authenticated by CUPS, any
additional group membership requirements are checked.
| NOTE:
The root user is considered by CUPS to be a member of every group.
|
Use the AuthType directive to enable Basic
authentication:
AuthType Basic
Digest authentication uses users and passwords defined in the
/etc/cups/passwd.md5 file to authenticate access to resources
such as printers and classes, and to limit access to administrative
functions.
| NOTE:
Unlike Basic authentication, Digest passes the MD5 sum (basically a
complicated checksum) of the username and password instead of the
strings themselves. Also, Digest authentication does not use the UNIX
password file, so if an attacker does discover the original password it
is less likely to result in a serious security problem so long as you
use a different UNIX password than the corresponding Digest password.
The current CUPS implementation of Digest authentication uses the
client's hostname or IP address for the "nonce" value. The nonce value
is an additional string added to the username and password to make
guessing the password more difficult. The server checks that the nonce
value matches the client's hostname or address and rejects the MD5 sum
if it doesn't. Future versions of CUPS will support Digest "session"
authentication which adds the request data to the MD5 sum, providing
even better authentication and security.
Digest authentication does not guarantee that an attacker cannot gain
unauthorized access, but it is safer than Basic authentication and
should be used in place of Basic authentication whenever possible.
Support for Digest authentication in web browsers is not yet
universally available.
|
The lppasswd(1) command is used to add, change, or
remove accounts from the passwd.md5 file. To add a user to
the default system group, type:
lppasswd -a user ENTER
Password: (password) ENTER [password is not echoed]
Password again: (password) ENTER [password is not echoed]
Once added, a user can change his/her password by typing:
lppasswd ENTER
Old password: (password) ENTER [password is not echoed]
Password: (password) ENTER [password is not echoed]
Password again: (password) ENTER [password is not echoed]
To remove a user from the password file, type:
lppasswd -x user ENTER
Once a valid username and password is authenticated by CUPS, any
additional group membership requirements are checked.
| NOTE:
The root user is considered by CUPS to be a member of every group.
|
Use the AuthType directive to enable Digest
authentication:
AuthType Digest
The AuthClass directive
controls the level of authentication to perform. System
and Group authentication extend the normal user-based
authentication to require membership in a UNIX group. For System
authentication each user must belong to the sys,
system, or root group; the actual group depends on
the operating system.
For Group authentication each user must belong to the
group named by the AuthGroupName
directive:
<Location /path>
AuthType Digest
AuthClass Group
AuthGroupName mygroup
</Location>
The named group must be a valid UNIX user group, usually defined in
the /etc/group or /etc/netgroup files.
Additionally, when using Digest authentication you need to create user
accounts with the named group:
lppasswd -g mygroup -a user ENTER
Password: (password) ENTER [password is not echoed]
Password again: (password) ENTER [password is not echoed]
CUPS maintains a log of all accesses, errors, and pages that are
printed. The log files are normally stored in the /var/log/cups
directory. You can change this by editing the /etc/cups/cupsd.conf
configuration file.
The access_log file lists each HTTP resource that is
accessed by a web browser or CUPS/IPP client. Each line is in the
so-called "Common Log Format" used by many web servers and web
reporting tools:
host group user date-time \"method resource version\" status bytes
127.0.0.1 - - [20/May/1999:19:20:29 +0000] "POST /admin/ HTTP/1.1" 401 0
127.0.0.1 - mike [20/May/1999:19:20:31 +0000] "POST /admin/ HTTP/1.1" 200 0
The host field will normally only be an IP address unless you
have enabled the HostNameLookups
directive in the cupsd.conf file.
The group field always contains "-" in CUPS.
The user field is the authenticated username of the requesting
user. If no username and password is supplied for the request then this
field contains "-".
The date-time field is the date and time of the request in
local time and is in the format:
[DD/MON/YYYY:HH:MM:SS +ZZZZ]
where ZZZZ is the timezone offset in hours and minutes from
coordinated universal time (UTC). UTC may sometimes be referred to as
GMT or ZULU on legacy systems.
The method field is the HTTP method used ("GET", "PUT",
"POST", etc.)
The resource field is the filename of the requested resource.
The version field is the HTTP specification version used by
the client. For CUPS clients this will always be "HTTP/1.1".
The status field contains the HTTP result status of the
request. Usually it is "200", but other HTTP status codes are possible.
For example, 401 is the "unauthorized access" status in the example
above.
The bytes field contains the number of bytes in the request.
For POST requests the bytes field contains the number of bytes
that was received from the client.
The error_log file lists messages from the scheduler
(errors, warnings, etc.):
level date-time message
I [20/May/1999:19:18:28 +0000] Job 1 queued on 'DeskJet' by 'mike'.
I [20/May/1999:19:21:02 +0000] Job 2 queued on 'DeskJet' by 'mike'.
I [20/May/1999:19:22:24 +0000] Job 2 was cancelled by 'mike'.
The level field contains the type of message:
E - An error occurred.W - The server was unable to perform some action.I - Informational message.D - Debugging message.
The date-time field contains the date and time of when the
page started printing. The format of this field is identical to the
data-time field in the access_log file.
The message fields contains a free-form textual message.
The page_log file lists each page that is sent to a
printer. Each line contains the following information:
printer user job-id date-time page-number num-copies job-billing hostname
DeskJet root 2 [20/May/1999:19:21:05 +0000] 1 0 acme-123 localhost
The printer field contains the name of the printer that
printed the page. If you send a job to a printer class, this field will
contain the name of the printer that was assigned the job.
The user field contains the name of the user (the IPP
requesting-user-name attribute) that submitted this file for
printing.
The job-id field contains the job number of the page being
printed. Job numbers are reset to 1 whenever the CUPS server is
started, so don't depend on this number being unique!
The date-time field contains the date and time of when the
page started printing. The format of this field is identical to the
data-time field in the access_log file.
The page-number and num-pages fields contain the page
number and number of copies being printed of that page. For printer
that can not produce copies on their own, the num-pages field
will always be 1.
The job-billing field contains a copy of the job-billing
attribute provided with the IPP create-job or
print-job requests or "-" if none was provided.
The hostname field contains the name of the host (the IPP
job-originating-host-name attribute) that originated the print
job.
CUPS provides a MIME-based file typing and filtering mechanism to
convert files to a printable format for each printer. On startup the
CUPS server reads MIME database files from the /etc/cups
directory (or a directory specified by the
ServerRoot directive) to build a file type and conversion
database in memory. These database files are plain ASCII text and can
be edited with your favorite text editor.
The mime.types and mime.convs files define the
standard file types and filters that are available on the system.
The mime.types file defines the known file types. Each
line of the file starts with the MIME type and may be followed by one
or more file type recognition rules. For example, the text/html
file type is defined as:
text/html html htm \
printable(0,1024) + \
(string(0,"<HTML>") string(0,"<!DOCTYPE"))
The first two rules say that any file with an extension of .html
or .htm is a HTML file. The third rule says that any file
whose first 1024 characters are printable text and starts with the
strings <HTML> or <!DOCTYPE is a HTML file as
well.
The first two rules deal solely with the name of the file being
typed. This is useful when the original filename is known, however for
print files the server doesn't have a filename to work with. The third
rule takes care of this possibility and automatically figures out the
file type based upon the contents of the file instead.
The available tests are:
( expr ) - Parenthesis for expression grouping+ - Logical AND, or whitespace - Logical OR! - Logical NOTmatch("pattern") - Pattern match on filenameextension - Pattern match on "*.extension"ascii(offset,length) - True if bytes are valid
printable ASCII (CR, NL, TAB, BS, 32-126)printable(offset,length) - True if bytes are printable
8-bit chars (CR, NL, TAB, BS, 32-126, 160-254)string(offset,"string") - True if bytes are identical
to stringistring(offset,"string") - True if bytes are identical
to string after reducing both strings to lowercasecontains(offset,range,"string") - True if the range of
bytes contains the stringchar(offset,value) - True if byte is identicalshort(offset,value) - True if 16-bit integer is
identical (network or "big-endian" byte order)int(offset,value) - True if 32-bit integer is identical
(network or "big-endian" byte order)locale("string") - True if current locale matches
string
All numeric values can be in decimal (123), octal (0123), or
hexadecimal (0x123) as desired.
Strings can be in quotes, all by themselves, as a string of
hexadecimal values, or some combination:
"string"
'string'
string
<737472696e67>
<7374>ring
As shown in the text/html example, rules can continue on
multiple lines using the backslash (\) character. A more complex
example is the image/jpeg rules:
image/jpeg jpeg jpg jpe string(0,<FFD8FF>) &&\
(char(3,0xe0) char(3,0xe1) char(3,0xe2) char(3,0xe3)\
char(3,0xe4) char(3,0xe5) char(3,0xe6) char(3,0xe7)\
char(3,0xe8) char(3,0xe9) char(3,0xea) char(3,0xeb)\
char(3,0xec) char(3,0xed) char(3,0xee) char(3,0xef))
This rule states that any file with an extension of .jpeg,
.jpg, or .jpe is a JPEG file. In addition, any file
starting with the hexadecimal string <FFD8FF> (JPEG
Start-Of-Image) followed by a character between and including
0xe0 and 0xef (JPEG APPn markers) is also a JPEG
file.
The mime.convs file defines all of the filter programs
that are known to the system. Each line consists of:
source destination cost program
text/plain application/postscript 50 texttops
application/vnd.cups-postscript application/vnd.cups-raster 50 pstoraster
image/* application/vnd.cups-postscript 50 imagetops
image/* application/vnd.cups-raster 50 imagetoraster
The source field is a MIME type, optionally using a wildcard
for the super-type or sub-type (e.g. "text/plain", "image/*",
"*/postscript").
The destination field is a MIME type defined in the
mime.types file.
The cost field defines a relative cost for the filtering
operation from 1 to 100. The cost is used to choose between two
different sets of filters when converting a file. For example, to
convert from image/jpeg to
application/vnd.cups-raster, you could use the imagetops
and pstoraster filters for a total cost of 100, or the
imagetoraster filter for a total cost of 50.
The program field defines the filter program to run; the
special program "-" can be used to make two file types equivalent. The
program must accept the standard filter arguments and environment
variables described in the CUPS Interface Design Description and CUPS
Software Programmers Manual:
program job user title options [filename]
If specified, the filename argument defines a file to read
when filtering, otherwise the filter must read from the standard input.
All filtered output must go to the standard output.
Adding a new file type or filter is fairly straight-forward. Rather
than adding the new type and filter to the mime.types and
mime.convs files which are overwritten when you upgrade to a new
version of CUPS, you simple need to create new files with .types
and .convs extensions in the /etc/cups directory.
We recommend that you use the product or format name, e.g.:
myproduct.types
myproduct.convs
If you are providing a filter for a common file format or printer,
add the company or author name:
acme-msword.types
acme-msword.convs
This will help to prevent name collisions if you install many
different file types and filters.
Once you choose the names for these files, create them using your
favorite text editor as described earlier in this chapter. Once you
have created the files, restart the cupsd process as
described earlier in "Restarting the CUPS Server"
.
Most CUPS printer drivers utilize one or more printer-specific
filters and a PPD file for each printer model. Printer driver filters
are registered via the PPD file using cupsFilter
attributes:
*cupsFilter: "application/vnd.cups-raster 0 rastertohp"
The filter is specified using the source file type only; the
destination file type is assumed to be printer/name -
suitable for sending to the printer.
CUPS supports an unlimited number of file formats and filters, and
can handle any printer. If you'd like to write a filter or printer
driver for your favorite file format or printer, consult the CUPS
Software Programmers Manual for step-by-step instructions.
This chapter describes how to print from client systems that use the
LPD, Mac OS, or Windows printing protocols.
CUPS is based on the IPP protocol, so any system that supports IPP
can send jobs to and receive jobs from CUPS automatically. However, not
all systems support IPP yet. This chapter will show you how to connect
these systems to your CUPS server, either to accept jobs from your
server for printing, or to send jobs to your server.
CUPS supports limited functionality for LPD-based clients. With LPD
you can print files to specific printers, list the queue status, and so
forth. However, the automatic client configuration and printer options
are not supported by the LPD protocol, so you must manually configure
each client for the printers it needs to access.
The cups-lpd(8) program provides support for LPD clients
and can be used from either the inetd(8) or
xinetd(8) programs. Add the following line to the
/etc/inetd.conf file to enable LPD support on your server through
the inetd program:
printer stream tcp nowait lp /usr/lib/cups/daemon/cups-lpd cups-lpd
The path to the cups-lpd may vary depending on your
installation.
Once you have added this line, send the inetd process a
HUP signal or reboot the system:
killall -HUP inetd ENTER [IRIX and some versions of Linux]
kill -HUP pid ENTER [Others]
reboot ENTER [For all systems if the HUP signal fails]
If you are using the xinetd program, create a file named
/etc/xinetd.d/printer containing the following lines:
service printer
{
socket_type = stream
protocol = tcp
wait = no
user = lp
server = /usr/lib/cups/daemon/cups-lpd
}
The xinetd program automatically reads the new
configuration file and enables LPD printing support.
| Warning:
cups-lpd currently does not perform any access control
based on the settings in cupsd.conf or in the
hosts.allow or hosts.deny files used by TCP wrappers.
Therefore, running cups-lpd on your server will allow any
computer on your network (and perhaps the entire Internet) to print to
your server.
While xinetd has built-in access control support, you
should use the TCP wrappers package with inetd to limit
access to only those computers that should be able to print through
your server.
|
CUPS provides the lpd backend for printing to LPD-based
servers and printers. Use a device URI of lpd://server/name
to print to a printer on an LPD server, where server is
the hostname or IP address of the server and name is the
queue name. Additional options can be specified after the remote queue
name to control how the LPD requests are sent - consult
Appendix B - Common Network Settings for a complete description.
Microsoft Windows NT provides an LPD service under the name "TCP/IP
Printing Services". To enable LPD printing on NT, open the "Services"
control panel, select the "TCP/IP Printing Services" service, and click
on the "Start" button. Any shared printer will then be available via
the LPD protocol.
Since Mac OS 10.2 uses CUPS as its printing system, all CUPS printers
will be available to the clients automatically.
| Note:
Certain legacy MacOS X applications, including most Adobe
applications, produce PICT files with embedded PostScript. Since the
filter needed to convert these files to pure PostScript is only
available on MacOS X, you need to either use a MacOS X print server or
replace the MacOS X IPP backend with the standard CUPS IPP backend. The
CUPS IPP backend will detect and locally convert these print files to
PostScript prior to sending the job to the server.
|
CUPS does not provide support for Mac OS 10.1 and earlier directly.
However, there are several free and commercial software packages that
do.
Because the CAP LaserWriter server (lwsrv(8)) does not
support specification of PPD files, we do not recommend that you use
CAP with CUPS. However, you can run the lpsrv program for
limited printing with the command:
lwsrv -n "Name" -p printer -a /usr/lib/adicts -f /usr/lib/LW+Fonts
where Name is the name you want to use when sharing the
printer, and printer is the name of the CUPS print queue.
To use your system as a print server for Mac OS clients, configure
each printer using a papserver(8) in the
/usr/adm/appletalk/services file, specifying the corresponding
PPD file in the /etc/cups/ppd directory for each printer.
For a printer named MyPrinter the entry would look like:
/usr/etc/appletalk/papserver -I -L -P /etc/cups/ppd/MyPrinter.ppd \
"Printer Description" MyPrinter
| NOTE:
Enter the text above on a single line without the backslash (\)
character.
|
To use your system as a print server for Mac OS clients, configure
each printer in the papd.conf file, specifying the
corresponding PPD file in the /etc/cups/ppd directory for
each printer. For a printer named MyPrinter the entry
would look like:
Printer Name@Zone Name:\
:pr=|/usr/bin/lp -d MyPrinter:\
:op=daemon:\
:pd=/etc/cups/ppd/MyPrinter.ppd:
Since MacOS 10.2 and later use CUPS, all you need to do is enable
printer sharing to allow CUPS clients to print to a Mac OS server. You
will need to download and install ESP Ghostscript on your server to
provide PostScript printing support for non-PostScript printers,
however.
CUPS currently does not provide a backend to communicate with a Mac
OS 10.1 and earlier server. However, you can write and install a short
shell script in the /usr/lib/cups/backend directory that
sends a print file using the appropriate command. The following is a
short script that will run the papif command provided with
CAP.
After copying this script to /usr/lib/cups/backend/cap,
specify a device URI of cap://server/printer to use this
backend with a print queue.
"/usr/lib/cups/backend/cap"
#!/bin/sh
#
# Usage: cap job user title copies options [filename]
#
# No arguments means show available devices...
if test ${#argv} = 0; then
echo "network cap \"Unknown\" \"Mac OS Printer via CAP\""
exit 0
fi
# Collect arguments...
user=$2
copies=$4
if test ${#argv} = 5; then
# Get print file from stdin; copies have already been handled...
file=/var/tmp/$$.prn
copies=1
cat > $file
else
# Print file is on command-line...
file=$6
fi
# Create a dummy cap.printers file for this printer based
# upon a device URI of "cap://server/printer"...
echo $PRINTER/$DEVICE_URI | \
awk -F/ '{print $1 "=" $5 ":LaserWriter@" $4}' > /var/tmp/$$.cap
CAPPRINTERS=/var/tmp/$$.cap; export CAPPRINTERS
# Send the file to the printer, once for each copy. This assumes that you
# have properly initialized the cap.printers file...
while [ $copies -gt 0 ]; do
papif -n $user < $file
copies=`expr $copies - 1`
done
# Remove any temporary files...
if test ${#argv} = 5; then
/bin/rm -f $file
fi
/bin/rm -f /var/tmp/$$.cap
exit 0
While CUPS does not provide Windows support directly, the free SAMBA
software package does. SAMBA version 2.0.6 is the first release of
SAMBA that supports CUPS. You can download SAMBA from:
http://www.samba.org
To configure SAMBA for CUPS, edit the smb.conf file and
replace the existing printing commands and options with the line:
printing = cups
printcap name = cups
That's all there is to it! Remote users will now be able to browse
and print to printers on your system.
You can optionally export printer drivers from your CUPS server using
the cupsaddsmb command and the SAMBA 2.2.0 or higher
software.
Before you can export the printers you must download the CUPS drivers
for Windows from the CUPS site (
http://www.cups.org/) or the current Adobe PostScript printer
drivers from the Adobe web site (
http://www.adobe.com/). If you download the Adobe drivers, use the
free unzip software to extract the files from the
self-extracting ZIP file containing the drivers; you will need the
following files:
ADFONTS.MFM
ADOBEPS4.DRV
ADOBEPS4.HLP
ADOBEPS5.DLL
ADOBEPSU.DLL
ADOBEPSU.HLP
DEFPRTR2.PPD
ICONLIB.DLL
PSMON.DLL
Copy these files to the /usr/share/cups/drivers directory
- you may need to rename some of the files so the filenames are all
UPPERCASE.
Next, configure SAMBA (via the smb.conf file) to support
printing through CUPS and provide a printer driver download share, as
follows:
[global]
load printers = yes
printing = cups
printcap name = cups
[printers]
comment = All Printers
path = /var/spool/samba
browseable = no
public = yes
guest ok = yes
writable = no
printable = yes
printer admin = root
[print$]
comment = Printer Drivers
path = /etc/samba/drivers
browseable = yes
guest ok = no
read only = yes
write list = root
This configuration assumes a FHS-compliant installation of SAMBA;
adjust the [printers] and [print$] share paths accordingly on your
system as needed. That is, the directory for your printer drivers can
be anywhere on the system; just make sure it is writable by the users
specified by the write list directive plus readable and
executable by all users. Also, make sure that you have SAMBA passwords
defined for each user in the write list using SAMBA's
smbpasswd(1) command. Otherwise you will not be able to
authenticate.
Finally, run the cupsaddsmb command to export the
printer drivers for one or more queues:
cupsaddsmb -U root printer1 ... printerN ENTER
Running cupsaddsmb with the -a option will
export all printers:
cupsaddsmb -U root -a ENTER
Notice in the above examples that the user root was used
which was defined in the write list of the smb.conf
file.
CUPS can print to Windows servers in one of two ways. The first way
uses the LPD protocol on the CUPS system and the "TCP/IP Printing
Services" on the Windows system. You can find out more about this
configuration in the LPD section earlier in this
chapter.
The second way is through the Microsoft Server Message Block ("SMB")
protocol. Support for this protocol is provided with the free SAMBA
software package. You can download SAMBA from:
http://www.samba.org
To configure CUPS for SAMBA, run the following command:
ln -s `which smbspool` /usr/lib/cups/backend/smb ENTER
The smbspool(1) program is provided with SAMBA starting
with SAMBA 2.0.6. Once you have made the link you can configure your
printers with one of the following device URIs:
smb://workgroup/server/sharename
smb://server/sharename
smb://user:pass@workgroup/server/sharename
smb://user:pass@server/sharename
The workgroup name need only be specified if your system
is using a different workgroup. The user:pass strings are
required when printing to Windows NT servers or to shares with
passwords enabled under Windows 95 and 98.
Copyright 1997-2005 by Easy Software Products
44141 AIRPORT VIEW DR STE 204
HOLLYWOOD, MARYLAND 20636 USA
Voice: +1.301.373.9600
Email: cups-info@cups.org
WWW: http://www.cups.org
The Common UNIX Printing SystemTM, ("CUPSTM"),
is provided under the GNU General Public License ("GPL") and GNU
Library General Public License ("LGPL"), Version 2, with exceptions for
Apple operating systems and the OpenSSL toolkit. A copy of the
exceptions and licenses follow this introduction.
The GNU LGPL applies to the CUPS API library, located in the "cups"
subdirectory of the CUPS source distribution and in the "cups" include
directory and library files in the binary distributions. The GNU GPL
applies to the remainder of the CUPS distribution, including the
"pdftops" filter which is based upon Xpdf and the CUPS imaging library.
For those not familiar with the GNU GPL, the license basically allows
you to:
- Use the CUPS software at no charge.
- Distribute verbatim copies of the software in source or binary form.
- Sell verbatim copies of the software for a media fee, or sell
support for the software.
- Distribute or sell printer drivers and filters that use CUPS so long
as source code is made available under the GPL.
What this license does not allow you to do is make changes or
add features to CUPS and then sell a binary distribution without source
code. You must provide source for any new drivers, changes, or
additions to the software, and all code must be provided under the GPL
or LGPL as appropriate. The only exceptions to this are the portions of
the CUPS software covered by the Apple operating system license
exceptions outlined later in this license agreement.
The GNU LGPL relaxes the "link-to" restriction, allowing you to
develop applications that use the CUPS API library under other licenses
and/or conditions as appropriate for your application.
In addition, as the copyright holder of CUPS, Easy Software Products
grants the following special exceptions:
- Apple Operating System Development License Exception;
- Software that is developed by any person or entity for an Apple
Operating System ("Apple OS-Developed Software"), including but not
limited to Apple and third party printer drivers, filters, and backends
for an Apple Operating System, that is linked to the CUPS imaging
library or based on any sample filters or backends provided with CUPS
shall not be considered to be a derivative work or collective work
based on the CUPS program and is exempt from the mandatory source code
release clauses of the GNU GPL. You may therefore distribute linked
combinations of the CUPS imaging library with Apple OS-Developed
Software without releasing the source code of the Apple OS-Developed
Software. You may also use sample filters and backends provided with
CUPS to develop Apple OS-Developed Software without releasing the
source code of the Apple OS-Developed Software.
- An Apple Operating System means any operating system software
developed and/or marketed by Apple Computer, Inc., including but not
limited to all existing releases and versions of Apple's Darwin, Mac OS
X, and Mac OS X Server products and all follow-on releases and future
versions thereof.
- This exception is only available for Apple OS-Developed Software and
does not apply to software that is distributed for use on other
operating systems.
- All CUPS software that falls under this license exception have the
following text at the top of each source file:
This file is
subject to the Apple OS-Developed Software exception.
- OpenSSL Toolkit License Exception;
- Easy Software Products explicitly allows the compilation and
distribution of the CUPS software with the OpenSSL Toolkit.
No developer is required to provide these exceptions in a derived
work.
Easy Software Products has trademarked the Common UNIX Printing
System, CUPS, and CUPS logo. You may use these names and logos in any
direct port or binary distribution of CUPS. Please contact Easy
Software Products for written permission to use them in derivative
products. Our intention is to protect the value of these trademarks and
ensure that any derivative product meets the same high-quality
standards as the original.
Easy Software Products also sells rights to the CUPS source code
under a binary distribution license for vendors that are unable to
release source code for their drivers, additions, and modifications to
CUPS under the GNU GPL and LGPL. For information please contact us at
the address shown above.
The Common UNIX Printing System provides a "pdftops" filter that is
based on the Xpdf software. For binary distribution licensing of this
software, please contact: Derek B. Noonburg
Email: derekn@foolabs.com
WWW:
http://www.foolabs.com/xpdf/
Easy Software Products sells software support for CUPS as well as a
commercial printing product based on CUPS called ESP Print Pro. You can
find out more at our web site:
http://www.easysw.com/
Version 2, June 1991
Copyright 1989, 1991 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim
copies of this license document, but changing it is not allowed.
The licenses for most software are designed to take away your freedom
to share and change it. By contrast, the GNU General Public License is
intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it in
new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
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you have. You must make sure that they, too, receive or can get the
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We protect your rights with two steps: (1) copyright the software,
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Also, for each author's protection and ours, we want to make certain
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Finally, any free program is threatened constantly by software
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The precise terms and conditions for copying, distribution and
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TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest
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Copyright (C) yyyy name of author
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You should have received a copy of the GNU General Public License
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Also add information on how to contact you by electronic and paper
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If the program is interactive, make it output a short notice like
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Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
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The hypothetical commands `show w' and `show c'
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Yoyodyne, Inc., hereby disclaims all copyright
interest in the program `Gnomovision'
(which makes passes at compilers) written
by James Hacker.
signature of Ty Coon, 1 April 1989
Ty Coon, President of Vice
Version 2, June 1991
Copyright (C) 1991 Free Software Foundation, Inc.
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
Everyone is permitted to copy and distribute verbatim copies
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[This is the first released version of the library GPL. It is
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END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Libraries
If you develop a new library, and you want it to be of the greatest
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To apply these terms, attach the following notices to the library. It
is safest to attach them to the start of each source file to most
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one line to give the library's name and an idea of what it does.
Copyright (C) year name of author
This library is free software; you can redistribute it and/or
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License as published by the Free Software Foundation; either
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This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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You should have received a copy of the GNU Lesser General Public
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Also add information on how to contact you by electronic and paper
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You should also get your employer (if you work as a programmer) or
your school, if any, to sign a "copyright disclaimer" for the library,
if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in
the library `Frob' (a library for tweaking knobs) written
by James Random Hacker.
signature of Ty Coon, 1 April 1990
Ty Coon, President of Vice
That's all there is to it!
This appendix covers many of the popular TCP/IP network interfaces
and printer servers available on the market today.
When you first install a network printer or print server on your LAN,
you need to set the Internet Protocol ("IP") address. On most
higher-end "workgroup" printers, you can set the address through the
printer control panel. However, in most cases you will want to assign
the addresses remotely from your workstation. This makes administration
a bit easier and avoids assigning duplicate addresses accidentally.
To setup your printer or print server for remote address assignment,
you'll need the Ethernet Media Access Control ("MAC") address, also
sometimes called a node address, and the IP address you want to use for
the device. The Ethernet MAC address can often be found on the printer
test page or bottom of the print server.
The easiest way to set the IP address of a network device is to use
the arp(8) command. The arp sends an Address
Resolution Protocol ("ARP") packet to the specified Ethernet MAC
address, setting the network device's IP address:
arp -s ip-address ethernet-address ENTER
arp -s host.domain.com 08:00:69:00:12:34 ENTER
arp -s 192.0.2.2 08:00:69:00:12:34 ENTER
The most flexible way to remotely assign IP addresses under UNIX is
through the Reverse Address Resolution Protocol ("RARP"). RARP allows a
network device to request an IP address using its Ethernet MAC address,
and one or more RARP servers on the network will respond with an ARP
packet with the IP address the device can use.
RARP should be used when you have to manage many printers or print
servers, or when you have a network device that does not remember its
IP address after a power cycle. If you just have a single printer or
print server, the arp command is the way to go.
Some UNIX operating systems use a program called rarpd(8)
to manage RARP. Others, like Linux, support this protocol in the
kernel. For systems that provide the rarpd program you
will need to start it before RARP lookups will work:
rarpd ENTER
Under IRIX you can enable this functionality by default using:
chkconfig rarpd on ENTER
Both the rarpd program and kernel RARP support read a
list of Ethernet and IP addresses from the file /etc/ethers.
Each line contains the Ethernet address (colon delimited) followed by
an IP address or hostname like:
08:00:69:00:12:34 myprinter.mydomain.com
08:00:69:00:12:34 192.0.2.2
Add a line to this file and cycle the power on the printer or print
server to set its address.
The BOOTP protocol is used when you need to provide additional
information such as the location of a configuration file to the network
interface. Using the standard bootpd(8) program supplied
with UNIX you simply need to add a line to the /etc/bootptab
file; for IRIX:
myprinter 08:00:69:00:12:34 192.0.2.2 myprinter.boot
Newer versions of bootpd use a different format:
myprinter:ha=080069001234:ip=192.0.2.2:t144=myprinter.boot
The myprinter.boot file resides in the
/usr/local/boot directory by default. If you do not need to
provide a boot file you may leave the last part of the line blank.
| NOTE:
Some versions of UNIX do not enable the BOOTP service by default. The
/etc/inetd.conf usually contains a line for the BOOTP service
that can be uncommented if needed.
|
To test that the IP address has been successfully assigned and that
the printer is properly connected to your LAN, type:
ping ip-address ENTER
If the connection is working properly you will see something like:
ping myprinter ENTER
PING myprinter (192.0.2.2): 56 data bytes
64 bytes from 192.0.2.2: icmp_seq=0 ttl=15 time=5 ms
64 bytes from 192.0.2.2: icmp_seq=1 ttl=15 time=3 ms
64 bytes from 192.0.2.2: icmp_seq=2 ttl=15 time=3 ms
64 bytes from 192.0.2.2: icmp_seq=3 ttl=15 time=3 ms
If not, verify that the printer or print server is connected to the
LAN, it is powered on, the LAN cabling is good, and the IP address is
set correctly. You can usually see the current IP address and network
status by printing a configuration or test page on the device.
Once you have set the IP address you can access the printer or print
server using the ipp, lpd, or socket
backends. The following is a list of common network interfaces and
printer servers and the settings you should use with CUPS:
| Model/Manufacturer | Device
URI(s) |
|---|
| Apple LaserWriter | lpd://
address/PASSTHRU |
Axis w/o IPP
(see directions) | socket://address
:9100
socket://address:9101
socket://address:9102 |
| Axis w/IPP | ipp://address
/LPT1
ipp://address/LPT2
ipp://address/COM1 |
| Castelle LANpressTM |
lpd://address/pr1
lpd://address/pr2
lpd://address/pr3 |
| DPI NETPrint | lpd://address
/pr1
lpd://address/pr2
lpd://address/pr3 |
| EFI® Fiery® RIP | lpd://
address/print |
| EPSON® Multiprotocol Ethernet
Interface Board | socket://address |
| Extended System ExtendNET |
lpd://address/pr1
lpd://address/pr2
lpd://address/pr3 |
| Hewlett Packard JetDirect w/o IPP |
socket://address:9100
socket://address:9101
socket://address:9102 |
| Hewlett Packard JetDirect w/IPP |
ipp://address/ipp
ipp://address/ipp/port1
ipp://address/ipp/port2
ipp://address/ipp/port3 |
| Intel® NetportExpress XL, PRO/100 |
lpd://address/LPT1_PASSTHRU
lpd://address/LPT2_PASSTHRU
lpd://address/COM1_PASSTHRU |
| LexmarkTM MarkNet |
lpd://address/ps |
Linksys EtherFast®
(see directions) | socket://address
:4010
socket://address:4020
socket://address:4030 |
| Kodak® | lpd://address/ps |
| QMS® CrownNetTM |
lpd://address/ps |
| Tektronix® PhaserShareTM |
socket://address:9100 |
| XEROX® 4512 NIC | lpd://
address/PORT1 |
| XEROX® XNIC | lpd://address
/PASSTHRU |
| XEROX® (most others) | socket://
address:5503 |
The Axis print servers can be configured using ARP, RARP, or BOOTP.
However, on models that do not provide IPP support an additional step
must be performed to configure the TCP/IP portion of the print server
for use with CUPS.
Each print server contains a configuration file named config
that contains a list of network parameters used by the server. To
modify this file you must first download it from the print server using
the ftp(1) program:
ftp ip-address ENTER
Connected to ip-address.
220 Axis NPS ### FTP Printer Server V#.## MON DD YEAR ready.
ftp> user root ENTER
331 User name ok, need password
Password: pass ENTER (this is not echoed)
230 User logged in
ftp> get config ENTER
local: config remote: config
200 PORT command successful.
150 Opening data connection for config (192,0,2,2),
(mode ascii).
226 Transfer complete.
##### bytes received in #.## seconds (##### Kbytes/s)
ftp> quit ENTER
221 Goodbye.
Next, edit the file with your favorite text editor and locate the
lines beginning with:
RTN_OPT. : YES
RTEL_PR1. : 0
RTEL_PR2. : 0
RTEL_PR3. : 0
RTEL_PR4. : 0
RTEL_PR5. : 0
RTEL_PR6. : 0
RTEL_PR7. : 0
RTEL_PR8. : 0
Change the RTN_OPT line to read:
RTN_OPT. : NO
This disables the Reverse TELNET protocol and enables the standard
TELNET protocol on the print server. Next, assign a port number for
each parallel and serial port on the server as follows:
RTEL_PR1. : 9100
RTEL_PR2. : 9101
RTEL_PR3. : 9102
RTEL_PR4. : 9103
RTEL_PR5. : 9104
RTEL_PR6. : 9105
RTEL_PR7. : 9106
RTEL_PR8. : 9107
This essentially makes the Axis print server look like a Hewlett
Packard JetDirect EX print server. Save the file and then upload the
new config file using the ftp command:
ftp ip-address ENTER
Connected to ip-address.
220 Axis NPS ### FTP Printer Server V#.## MON DD YEAR ready.
ftp> user root ENTER
331 User name ok, need password
Password: pass ENTER (this is not echoed)
230 User logged in
ftp> put config CONFIG ENTER
local: config remote: CONFIG
200 PORT command successful.
150 Opening data connection for config (192,0,2,2), (mode ascii).
226 Transfer complete.
##### bytes received in #.## seconds (##### Kbytes/s)
ftp> get hardreset ENTER
local: hardreset remote: hardreset
200 PORT command successful.
421 Axis NPS ### hard reset, closing connection.
ftp> quit ENTER
221 Goodbye.
Your Axis print server is now ready for use!
The Linksys print servers can be configured using ARP, RARP, or
BOOTP. Like older Axis print servers, an additional step must be
performed to configure the TCP/IP portion of the print server for use
with CUPS.
Each print server contains a configuration file named CONFIG
that contains a list of network parameters used by the server. To
modify this file you must first download it from the print server using
the ftp(1) program:
ftp -n ip-address ENTER
Connected to ip-address.
220 Print Server Ready.
Remote system type is Print.
ftp> get CONFIG ENTER
local: CONFIG remote: CONFIG
200 Command OK.
150 Open ASCII Mode Connection.
WARNING! 68 bare linefeeds received in ASCII mode
File may not have transferred correctly.
226 Transfer complete.
##### bytes received in #.## seconds (##### Kbytes/s)
ftp> quit ENTER
221 Goodbye.
Next, edit the file with your favorite text editor and locate the
lines beginning with:
0100 L1_PROUT:P1
0120 L2_PROUT:P1
0140 L3_PROUT:P1
Change the port number for each parallel and serial port on the
server as follows:
0100 L1_PROUT:P1
0120 L2_PROUT:P2
0140 L3_PROUT:P3
This maps each virtual printer with a physical port. Save the file
and then upload the new CONFIG file using the ftp
command:
ftp -n ip-address ENTER
Connected to ip-address.
220 Print Server Ready.
Remote system type is Print.
ftp> put CONFIG ENTER
local: CONFIG remote: CONFIG
200 Command OK.
150 Open ASCII Mode Connection.
226 Transfer complete.
##### bytes received in #.## seconds (##### Kbytes/s)
ftp> quit ENTER
221 Goodbye.
Your Linksys print server is now ready for use!
The LPD backend supports several options which are included in the
device URI, e.g.:
lpd://server/name?option1=value1+option2=value2+...+optionN=valueN
The following table summarizes the options and values that are
supported:
| Option=Value | Description |
|---|
banner=off
banner=no
banner=false | Does not request a LPD banner
page for the job. (Default) |
banner=on
banner=yes
banner=true | Requests a LPD banner page for the
job. |
format=c
format=d
format=f
format=g
format=l
format=n
format=o
format=p
format=r
format=t
format=v | Specifies the LPD format code of the
print job. "format=l" is raw output, while "format=o" is PostScript.
(Default is "format=l" for raw output) |
manual_copies=off
manual_copies=no
manual_copies=false | Specifies that the backend
should not send multiple copies of a print job in the print data file. |
manual_copies=on
manual_copies=yes
manual_copies=true | Specifies that the backend
should send multiple copies of a print job in the print data file to
print more than one copy. (Default) |
| order=control,data | Specifies that the LPD
control file should be sent before the print data file. (Default) |
| order=data,control= | Specifies that the
print data file should be sent before the LPD control file. |
reserve=off
reserve=no
reserve=false | Specifies that the backend
should not reserve a priviledged source port as required by RFC 1179. |
reserve=on
reserve=yes
reserve=true
reserve=rfc1179 | Specifies that the backend
should reserve a priviledges source port from 721 to 731 inclusive as
required by RFC 1179. This option may cause reduced printing
performance when more than 11 LPD printers are defined on the server
due to port contention issues. |
| reserve=any | Specifies that the backend
should reserve a priviledges source port from 1 to 1023 inclusive. This
often works with LPD implementations that require a priviledged source
port but do not limit it to the range defined by RFC 1179, allowing for
more printers to be active at the same time. (Default) |
sanitize_title=off
sanitize_title=no
sanitize_title=false | Specifies that the
backend should not sanitize the job title string. (Default on OSX) |
sanitize_title=on
sanitize_title=yes
sanitize_title=true | Specifies that the backend
should sanitize the job title string. (Default on all but OSX) |
| timeout=N | Specifies the response timeout
for all LPD commands and transactions in seconds. (Default is 300
seconds) |
This appendix lists the printer drivers that are provided with CUPS.
CUPS includes the following printer drivers:
The DYMO Label Printer driver (dymo.ppd) supports the DYMO
LabelWriter 300 series (300/310/315/320/330/330 Turbo) thermal label
printers. It provides 136, 203, and 300 DPI output in black only.
The EPSON 9-pin Dot Matrix driver (epson9.ppd) supports
9-pin dot matrix printers that implement the ESC/P command set. It
provides 60x72, 120x72, and 240x72 DPI output in black only.
The EPSON 24-pin Dot Matrix driver (epson9.ppd) supports
24-pin dot matrix printers that implement the ESC/P command set. It
provides 120x180, 180x180, 360x180, and 360x360 DPI output in black
only.
The EPSON Stylus Color driver (stcolor.ppd) supports EPSON
Stylus Color printers that implement the ESC/P2 command set. It
provides 180, 360, and 720 DPI output in black and color (CMYK).
The EPSON Stylus Photo driver (stphoto.ppd) supports EPSON
Stylus Photo printers that implement the ESC/P2 command set. It
provides 180, 360, and 720 DPI output in black and color (CMYKcm).
The HP DeskJet driver (deskjet.ppd) supports HP DeskJet
printers that implement the PCL command set. It provides 150, 300, and
600 DPI output in black and color (CMYK).
The DeskJet printers that implement the HP-PPA command set (720C,
722C, 820C, and 1100C) are not supported due to a complete lack
of documentation and support from Hewlett Packard.
The duplexer provided with the HP DeskJet 900 series printers is also
not supported for similar reasons.
The HP LaserJet driver (laserjet.ppd) supports HP LaserJet
printers that implement the PCL command set. It provides 150, 300, and
600 DPI output in black only and supports the duplexer if installed.
LaserJet printers that do not implement PCL (3100, 3150) are not
supported due to a complete lack of documentation and support from
Hewlett Packard.
This appendix lists the files and directories that are installed for
the Common UNIX Printing System.
| Pathname | Description |
|---|
| /etc/cups/certs/ | The location of
authentication certificate files for local HTTP clients. |
| /etc/cups/classes.conf | The printer classes
configuration file for the scheduler. |
| /etc/cups/cupsd.conf | The scheduler
configuration file. |
| /etc/cups/interfaces/ | The location of
System V interface scripts for printers. |
| /etc/cups/mime.convs | The list of standard
file filters included with CUPS. |
| /etc/cups/mime.types | The list of recognized
file types for CUPS. |
| /etc/cups/ppd/ | The location of PostScript
Printer Description ("PPD") files for printers. |
| /etc/cups/printers.conf | The printer
configuration file for the scheduler. |
| /usr/bin/cancel | The System V cancel job(s)
command. |
| /usr/bin/disable | The System V disable
printer command. |
| /usr/bin/enable | The System V enable printer
command. |
| /usr/bin/lp | The System V print command. |
| /usr/bin/lpoptions | Sets user-defined
printing options and defaults. |
| /usr/bin/lppasswd | Adds, changes, or removes
Digest password accounts. |
| /usr/bin/lpq | The Berkeley status command. |
| /usr/bin/lpr | The Berkeley print command. |
| /usr/bin/lprm | The Berkeley cancel job(s)
command. |
| /usr/bin/lpstat | The System V status
command. |
| /usr/include/cups/ | CUPS API header files. |
/usr/lib32/libcups.a
/usr/lib32/libcupsimage.a | Static libraries (IRIX 6.5) |
/usr/lib/libcups.a
/usr/lib/libcupsimage.a | Static libraries (all others) |
/usr/lib/libcups.sl.2
/usr/lib/libcupsimage.sl.2 | Shared libraries (HP-UX) |
/usr/lib32/libcups.so.2
/usr/lib32/libcupsimage.so.2 | Shared libraries (IRIX 6.5) |
/usr/lib/libcups.so.2
/usr/lib/libcupsimage.so.2 | Shared libraries (all others) |
| /usr/libexec/cups/backend/ | Backends for
various types of printer connections (*BSD and OSX) |
| /usr/lib/cups/backend/ | Backends for various
types of printer connections (all others) |
| /usr/libexec/cups/cgi-bin/ | CGI programs for
the scheduler (*BSD and OSX) |
| /usr/lib/cups/cgi-bin/ | CGI programs for the
scheduler (all others) |
| /usr/libexec/cups/daemon/ | Daemons for
polling and LPD support (*BSD and OSX) |
| /usr/lib/cups/daemon/ | Daemons for polling
and LPD support (all others) |
| /usr/libexec/cups/filter/ | Filters for
various types of files (*BSD and OSX) |
| /usr/lib/cups/filter/ | Filters for various
types of files (all others) |
| /usr/lib/locale/ | The location of
language-specific message files. (System V) |
| /usr/lib/nls/msg/ | The location of
language-specific message files. (Compaq Tru64 UNIX) |
| /usr/share/locale/ | The location of
language-specific message files. (Linux, *BSD) |
| /usr/sbin/accept | The accept-jobs command. |
| /usr/sbin/cupsd | The CUPS print scheduler. |
| /usr/sbin/lpadmin | The System V printer
administration tool. |
| /usr/sbin/lpc | The Berkeley printer
administration tool. |
| /usr/sbin/lpinfo | The get-devices and
get-ppds command. |
| /usr/sbin/lpmove | The move-jobs command. |
| /usr/sbin/reject | The reject-jobs command. |
/usr/share/catman/a_man/
/usr/share/catman/u_man/ | Man pages (IRIX) |
| /usr/share/man/ | Man pages (Compaq Tru64
UNIX, HP-UX, Solaris) |
| /usr/man/ | Man pages (all others) |
| /usr/share/cups/data/ | The location of
filter data files. |
| /usr/share/cups/data/testprint.ps | The
PostScript test page file. |
| /usr/share/cups/fonts/ | The location of
PostScript fonts for the PostScript RIP. |
| /usr/share/cups/model/ | The location of
PostScript Printer Description ("PPD") files and interface scripts that
may be used to setup a printer queue. |
| /usr/share/cups/pstoraster/ | Other
PostScript RIP initialization files. |
| /usr/share/cups/pstoraster/Fontmap | The font
mapping file (converts filenames to fontnames) |
| /usr/share/cups/templates/ | The location of
HTML template files for the web interfaces. |
| /usr/share/doc/cups/ | Documentation and web
page data for the scheduler. |
| /var/log/cups/ | The location of scheduler
log files. |
| /var/spool/cups/ | The location of print
files waiting to be printed. |
This appendix covers some of the common problems first-time users
encounter when installing and configuring CUPS.
Commercial support for CUPS is available from Easy Software Products.
For more information please contact us at:
Many applications read the /etc/printcap file to get a
list of available printers.
The default CUPS configuration creates the /etc/printcap
file automatically. To enable or disable automatic creation and
updating of this file, use the Printcap
directive described in Chapter 6,
"Printing System Management".
CUPS will ask you for a UNIX username and password when you perform
printer administration tasks remotely or via a web browser. The default
configuration requires that you use the root username and
the corresponding password to authenticate the request.
CUPS does not allow you to authenticate an administration request
with an account that has no password for security reasons. If you do
not have a password on your root account then you won't be
able to add printers remotely or via the web interface!
To disable password authentication you need to edit the
/etc/cups/cupsd.conf file and comment out the lines reading:
AuthType Basic
AuthClass System
for the /admin location. Then restart the CUPS server as
described in Chapter 6, "Printing System
Management".
| NOTE:
Disabling password checks will allow any local user to change your
printer and class configuration, but remote administration from another
machine will still not be allowed.
|
The default CUPS configuration limits administration to the local
machine. To open up access, edit the /etc/cups/cupsd.conf
and comment out the lines reading:
Order deny,allow
Deny from all
Allow from 127.0.0.1
for the /admin location. Then restart the CUPS server as
described in Chapter 6, "Printing System
Management".
This problem is usually caused by:
- not specifying the correct password for the root account.
- accessing the CUPS server using the hostname or IP address of the
server without enabling remote access for administration functions.
This can be corrected by following the instructions in the
"I Can't Do Administration Tasks from Another Machine!" section
earlier in this appendix.
- not setting a password on the root account. CUPS will not
authenticate a user account that does not have a password for security
reasons.
- authenticating using an account other than root, but the account you
are using is not a member of the system group.
- configuring CUPS to use Digest authentication, but your web browser
does not support Digest authentication.
Under normal circumstances, "connection refused" messages for a
networked printer should be expected from time to time. Most network
interfaces only allow a single connection to be made at any given time
(one job at a time) and will refuse access to all other systems while
the first connection is active. CUPS automatically retries the
connection once every 30 seconds.
If the problem persists and you are unable to print any jobs to the
printer, verify that another machine is not maintaining a connection
with the printer, and that you have selected the proper port or printer
name for the printer.
Also, most external print servers will refuse connections if the
connected printer is turned off or is off-line. Verify that the
affected printer is turned on and is online.
If you get "write error" messages on a printer queue the printer
interface (usually a Hewlett Packard JetDirect interface) has timed out
and reset the network connection from your workstation.
The error is caused by that startup delay between the initial setup
of the printer or plotter and the first page of print data that is
sent.
To correct the problem, change the idle timeout on the interface to
at least 180 seconds or 3 minutes. To change the timeout on a Hewlett
Packard JetDirect interface, type:
telnet ip-address ENTER
Trying ip-address...
Connected to ip-address.
Escape character is `^]'.
Please type [Return] two times, to initialize telnet configuration
For HELP type "?"
> idle-timeout: 180 ENTER
> quit ENTER
|