cups(1) OpenPrinting cups(1)
NAME
cups - a standards-based, open source printing system
DESCRIPTION
CUPS is the software you use to print from applications like word
processors, email readers, photo editors, and web browsers. It converts
the page descriptions produced by your application (put a paragraph
here, draw a line there, and so forth) into something your printer can
understand and then sends the information to the printer for printing.
Now, since every printer manufacturer does things differently, printing
can be very complicated. CUPS does its best to hide this from you and
your application so that you can concentrate on printing and less on how
to print. Generally, the only time you need to know anything about your
printer is when you use it for the first time, and even then CUPS can
often figure things out on its own.
HOW DOES IT WORK?
The first time you print to a printer, CUPS creates a queue to keep
track of the current status of the printer (everything OK, out of paper,
etc.) and any pages you have printed. Most of the time the queue points
to a printer connected directly to your computer via a USB port, however
it can also point to a printer on your network, a printer on the Inter-
net, or multiple printers depending on the configuration. Regardless of
where the queue points, it will look like any other printer to you and
your applications.
Every time you print something, CUPS creates a job which contains the
queue you are sending the print to, the name of the document you are
printing, and the page descriptions. Job are numbered (queue-1, queue-2,
and so forth) so you can monitor the job as it is printed or cancel it
if you see a mistake. When CUPS gets a job for printing, it determines
the best programs (filters, printer drivers, port monitors, and back-
ends) to convert the pages into a printable format and then runs them to
actually print the job.
When the print job is completely printed, CUPS removes the job from the
queue and moves on to any other jobs you have submitted. You can also be
notified when the job is finished, or if there are any errors during
printing, in several different ways.
WHERE DO I BEGIN?
The easiest way to start is by using the web interface to configure your
printer. Go to "http://localhost:631" and choose the Administration tab
at the top of the page. Click/press on the Add Printer button and follow
the prompts.
When you are asked for a username and password, enter your login user-
name and password or the "root" username and password.
After the printer is added you will be asked to set the default printer
options (paper size, output mode, etc.) for the printer. Make any
changes as needed and then click/press on the Set Default Options button
to save them. Some printers also support auto-configuration -
click/press on the Query Printer for Default Options button to update
the options automatically.
Once you have added the printer, you can print to it from any applica-
tion. You can also choose Print Test Page from the maintenance menu to
print a simple test page and verify that everything is working properly.
You can also use the lpadmin(8) and lpinfo(8) commands to add printers
to CUPS. Additionally, your operating system may include graphical user
interfaces or automatically create printer queues when you connect a
printer to your computer.
HOW DO I GET HELP?
The OpenPrinting CUPS website (https://openprinting.github.io/cups) pro-
vides access to the cups and cups-devel mailing lists, additional docu-
mentation and resources, and a bug report database. Most vendors also
provide online discussion forums to ask printing questions for your op-
erating system of choice.
ENVIRONMENT
CUPS commands use the following environment variables to override the
default locations of files and so forth. For security reasons, these en-
vironment variables are ignored for setuid programs:
CUPS_ANYROOT
Whether to allow any X.509 certificate root (Y or N).
CUPS_CACHEDIR
The directory where semi-persistent cache files can be found.
CUPS_DATADIR
The directory where data files can be found.
CUPS_ENCRYPTION
The default level of encryption (Always, IfRequested, Never, Re-
quired).
CUPS_EXPIREDCERTS
Whether to allow expired X.509 certificates (Y or N).
CUPS_GSSSERVICENAME
The Kerberos service name used for authentication.
CUPS_SERVER
The hostname/IP address and port number of the CUPS scheduler
(hostname:port or ipaddress:port).
CUPS_SERVERBIN
The directory where server helper programs, filters, backend, etc.
can be found.
CUPS_SERVERROOT
The root directory of the server.
CUPS_STATEDIR
The directory where state files can be found.
CUPS_USER
Specifies the name of the user for print requests.
HOME Specifies the home directory of the current user.
IPP_PORT
Specifies the default port number for IPP requests.
LOCALEDIR
Specifies the location of localization files.
LPDEST
Specifies the default print queue (System V standard).
PRINTER
Specifies the default print queue (Berkeley standard).
TMPDIR
Specifies the location of temporary files.
FILES
~/.cups/client.conf
~/.cups/lpoptions
CONFORMING TO
CUPS conforms to the Internet Printing Protocol version 2.1 and imple-
ments the Berkeley and System V UNIX print commands.
NOTES
CUPS printer drivers, backends, and PPD files are deprecated and will no
longer be supported in a future feature release of CUPS. Printers that
do not support IPP can be supported using applications such as
ippeveprinter(1).
SEE ALSO
cancel(1), client.conf(5), cupsctl(8), cupsd(8), lp(1), lpadmin(8),
lpinfo(8), lpoptions(1), lpr(1), lprm(1), lpq(1), lpstat(1), CUPS Online
Help (http://localhost:631/help), OpenPrinting CUPS Web Site
(https://openprinting.github.io/cups), PWG Internet Printing Protocol
Workgroup (http://www.pwg.org/ipp)
COPYRIGHT
Copyright © 2020-2024 by OpenPrinting.
2021-02-28 CUPS cups(1)
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