Chapter 12

Guide to Linux Installation and Administration, 2e 1

Chapter 12

Printing in Linux


Objectives

In this chapter, you will:

• Configure and use the traditional Linux printing architecture

• Understand the Common UNIX Printing System (CUPS)

• Print files from different applications

• Locate and relieve system bottlenecks

• Manage networked printing resources


Using Traditional Linux Printing

• The traditional Linux printing architecture is called LPRng and is based on the system developed for BSD UNIX

• LPRng printing allows multiple users to print files at the same time to either local or networked printers

Valued Gateway Client:



The Printing Process

• Printer definitions, or print queues describe the type of printer and the features to be used when something is printed on it

• The file submitted for printing is called a print job• The print job is processed by a print filter• After sending the print job through a print filter,

the printing utility stores the print job in a print spool directory

• The print server program, lpd, keeps track of all the print jobs in all the print queues on the system




A Single Print Queue Can Refer to Multiple Physical Printers


Many Print Queues Can Refer to a Single Physical Printer


Understanding Print Filters and Drivers

• Linux uses special programs called print filters• A Linux print filter converts documents or images

into a format that the printer can use




Printer Languages

• A page description language is a special set of codes that determine the graphics elements, text font, and everything else about what appears on a printed page

• The most widely used page description languages are PostScript and Printer Control Language (PCL)




The Magic Filter

• Most Linux distributions use a “magic filter” that can convert documents into formats for many different printers

• The “magic filter” doesn’t generally allow Linux to use the specialized features of each printer




Configuring Local Printer Definitions

• A local printer is a printer directly attached to your computer

• Define one or more printers before you can print documents




Reviewing printcap

• Each LPRng printer definition is created as a print queue entry in the /etc/printcap configuration file

• To use a local printer, you must provide the appropriate Linux device name when you configure the printer

• The format of a printcap entry consists of a print queue name, followed by a series of two-character option codes that apply to that printer




Configuring printcap Graphically

• Several graphical tools can create basic printcap entries:– Printer Configuration Tool printconf-gui in Red Hat

Linux

– YAST utility in SuSE Linux

– Webmin in Caldera OpenLinux




Defining the Printer Name and Type in the printconf-gui Utility


Selecting a Printer Driver in printconf-gui


The Main Window of printconf-gui


Selecting the Print System to Configure within the KDE Control

Center


Selecting a Printer in the KDE Printer Manager Wizard


Reviewing Printer Driver Settings in KDE


Managing Printers in the KDE Control Center


Printing Remotely Using lpd

• Define a printer on your system that refers to the remote computer and a print queue on the remote system

• The lpd daemon on your computer communicates with the lpd program on the remote computer, transferring the print job




Printing to a Remote Printer Using lpd


Defining a Remote lpd-based Printer in printconf-gui


Defining a Remote lpd-based Printer in KDE


Understanding the Common Unix Printing System

• The Common UNIX Printing System (CUPS) provides a new architecture for Linux and UNIX printing

• CUPS lets users and system administrators browse the network to find and print to networked printers and other devices

• CUPS lets system administrators manage printer definitions and print jobs across the network




Configuring Printers within CUPS

• The cupsd print server daemon uses HTTP protocol and accepts requests and processes print jobs sent over the network

• The cupsd print server daemon manages printers using a Web browser interface

• The CUPS architecture uses network port 631 to communicate between CUPS-enabled print servers




The Main Page of the CUPS Browser-Based Interface


The Printers Page in the CUPS Web Interface


Configuring an Existing Printer in CUPS


Setting up CUPS Classes

• CUPS class is a group of printers to which a user can submit a print job

• Whichever printer within the class is first available will be used to print the job




The Classes Page within the CUPS Configuration


Printing Files

• You can print files– from a command line

– from a specialized graphical tool

– from any graphical application




Printing from a Command Line

• The basic printing command is lpr• The lpr command is used for printing to both

LPRng and CUPS-based printers• Command options for lpr apply to a specific print

job, not to all print jobs sent to the printer




Command Options for lpr


lpr Options Supported by CUPS


Printing from Graphical Applications

• You typically print from a graphical application by choosing Print from the File menu

• Graphical applications rely on the lpr utility• You can print to a file• Gnome and KDE applications build upon a

standard dialog box




The Print Dialog Box in Gnumeric


The Print Dialog Box in KWord


The Print Dialog Box in Netscape Communicator


Managing the Printing Environment

• A system administrator manages printing• The system administrator takes care about

printer supplies and solves printer-related problems




Deciding on Printing Policies

• A printing policy is a brief statement of rules describing how printing resources can be used and how printers will be managed

• A printing policy is a helpful document for any organization with more than two or three users who rely on the same printer




Using the lpc Utility

• The lpc utility is the printer control utility• The lpc command-line utility lets you control

LPRng or CUPS printing, specifying how print jobs are accepted and processed

• You must be root to use lpc• You can include an lpc command as a parameter

on the command line




lpc Commands


Using lpc to Control the Printing Process


Tracking Print Jobs

• To view the print jobs in the default print queue, the lpq command is used

• The lprm command deletes a print job from a queue




Using Graphical Print Management Utilities

• You can use two KDE graphical utilities to manage printing:– KDE Print Job Viewer

– KLpq program




The KDE Print Job Viewer


The KLpq Printing Manager


Managing CUPS Print Jobs in a Browser


Summary• The traditional Linux printing architecture is called

LPRng and is based on the system developed for BSD UNIX

• Printers are typically connected locally to either a parallel or serial port

• A system administrator creates printer definitions, which act as print queues

• Printer definitions are stored in /etc/printcap and can be created using printconf-gui or other text-mode or graphical tools

• Users submit print jobs to a named print queue using either the lpr command or a graphical dialog box


Summary• The data that a user submits as a print job is

processed using a print filter, which converts raw document data into a format a printer can understand, such as PCL or PostScript

• A printing policy informs users of how they can use printing resources and what they can expect from the system administrator who manages the printers

• The Common UNIX Printing System (CUPS) provides a new architecture for Linux and UNIX printing

• Print jobs waiting to be printed on a system using CUPS can be managed using the CUPS browser-based interface

Chapter 12

Documents

Transcript of Chapter 12