CIS 192B – Lesson 7

UNIX Printing

CIS 192B – Lesson 7

Printing Architecture

Clients Scheduler/ Backends Network Spooler

Named Queue

Named Queue

Named Queue

Script

Script

Script

Command-line

Graphic applications

daemon

CIS 192B – Lesson 7

The Components• The Print Spooler

– Collects and schedules jobs

• User-level Utilities– Command-line– Graphical

• Back Ends– Piped shell scripts that talk to devices

• A Newtork Protocol– Communication among spoolers

CIS 192B – Lesson 7

The CUPS Daemon

• The daemon: – cupsd

• Configuration files:– /etc/cups/cupsd.conf– /etc/cups/printers.conf

• Backend script files– /etc/cups/ppd/*.ppd

CIS 192B – Lesson 7

The Configuration File

• Very Apache-like• Important Directives:

– Port 631– BrowseAllow @LOCAL | All– BrowseAddress broadcast-addr:port– Allow from network-address

CIS 192B – Lesson 7

User Agents• Command-line:

– lpadmin– lpoptions– cupsenable– cupsdisable

• Graphic: Web based– http://localhost:631– http://server:631/printers– http://server:631/admin

CIS 192B – Lesson 7

Spooling

• Print Jobs are spooled in:– /var/spool/cups

• control files begin with ‘c’• data files begin with ‘d’