Printing

1
Printing

• Some printer jargon
• Spooler
• A piece of software
• Dpi
• Dots per inch
• PDL
• Page description languages
• Bitmap
• Common bitmap formats include JPEG, PNG, TIFF and
  GIF

2
Printing

• Some printer jargon (cont)
• RIP
• Raster Image Processor
• Converts PDL documents to a bitmap
• Filters
• Programs that modify jobs en route from the
  spooler to the printer
• Postscript
• The most common PDL found on Unix
• PCL
• Exclusively on Hp printers and quite common in PC
  world

3
Types of printers

• By connection interface
• Serial port
• parallel port
• Universal Serial Bus (USB)
• Network
• Full-fledged network interfaces
• Computer can spool directly to the network
  printer
• Many network laser printers include a lpd server
  that runs inside the printer.
• To simplify administration
• Set up a few host to control the printers
• Other machine simply transmit jobs to these print
  server machines

4
BSD Printing

• Redhat and FreeBSD use BSD printing system.
• Daemon lpd
• Accepts print jobs from users or other (remote)
  lpds
• Processes the jobs
• Sends jobs to an actual printer
• reads /etc/printcap and is started at boot time
• Program lpr allow users to submit print jobs to
  lpd.
• Lpr and lpd communicate through the unix socket
  /dev/printer
• Which printer to use
• Option -Pprinter
• Env PRINTER
• Default printer lp, or the first one in
  /etc/printcap

5
BSD Printing

• Spool
• Lpr create two files under the printers spool
  dir /var/spool/lpd/printername
• control file started with cf
• data file started with df
• Lpr notifies lpd of the jobs existence
• Lpd then check printcap to determine if the
  destination is local or remote
• If remote, lpd opens a connection to the remote
  machines lpd, transfer the cf and df file,and
  delete the local copy
• If local, lpd creates a series of UNIX pipes
  between the spool file and hardware to transport
  the data filter processes

6

• BSD printing commands

Command Location Function
lpq /usr/bin Shows print queue contents and status
lpr /usr/bin Queues jobs for printing
lprm /usr/bin Cancels a queued or printing job
lpc /usr/sbin Controls a printer or queue
lpd /usr/sbin Schedules and prints jobs
printtool /usr/bin Configures the printing system
7
BSD Printing

• lpc make administrative changes
• Enable or disable queuing for a particular
  printer
• enable/disable printer
• Enable or disable printing on a particular
  printer
• start/stop printer
• Remove all jobs from a printers queue
• clean printer
• Move a job to the top of a printers queue
• topq printer jobid
• topq printer username
• Start, stop or restart the lpd daemon
• restart printer
• Get printer status information
• status printer

8
BSD Printing

• /etc/printcap file
• BSD printing systems master database
• A printer must be described in the printcap file
  before jobs can be submitted it.
• Printcap format
• Namexxstringxxnumberxxstring

9

• Printcap variables

Name Type Meaning Example
sd string Spool directory sd/var/spool/lpd/howler-lw
lf string Error log file lf/var/log/lpr
lp string Device name lp/dev/lp0
af string Accounting file af/usr/adm/lpr.acct
rm string Remote machine name rmbeast.xor.com
rp string Remote printer name rphowler-lw
of string Output filter of/usr/libexec/lpr/lpf
if string Input filter if/usr/sbin/stylascii
mx number Maximum file size mx0
10
System V printing

• Used by HP-UX, SCO Unic, Solaris etc.
• System V spooling subsystems major components
• Spooling daemon lpsched responsible for carrying
  out print requests by sending data to the
  appropriate printer.
• User commands
• Initiate print requests lp
• Cancel a pending request cancel
• List queue contents lpstat
• Administrative commands
• Accept, reject, enable, disable, lpadmin, lpmove,
  lpusers

11
System V printing

• Spooling directories under /var/spool/lp/request
  named for each printer
• By default the actual file to print is not
  copied. The changing or deleting a file before it
  is printed affects the final output.
• Use c option to lp to copy the file to the spool
  area
• Device classes
• Group similar devices and declare them to be
  equivalent to and substitutable for one another.
• Setting the system default destination
• Use the d option to the lpadmin command
• lpadmin dprinter2
• lpstat d
• User may set the env LPDEST

12
System V printing

• Obtaining Destination Status Information
• Lpstat command
• Accept job or not -alist
• Display the members -clist
• List print requests -olist
• Display the current status -plist
• Display users jobs -ulist
• Display the special files -vlist
• Display summary -s
• Display all status info -t

13
System V printing

• Controlling print queues
• Use accept and reject commands to permit and
  inhibit spooling to a print queue.
• Example
• reject r There is no paper in the entire
  building laserprinter
• accept laserprinter
• Controlling the status of a particular printing
  device
• Use enable and disable commands followed by a
  device
• Example
• disable r changing toner cartridge back by
  11 laserpritner
• enable laserprinter

14
System V printing

• Starting and stopping the print service
• Started automatically at system boottime
• Such as /etc/rc2.d/S80lp
• Check if the scheduler is running
• lpstat r
• Stop and start printing service manually
• lpshut
• /etc/rc2.d/S80lp start
• Managing printers and destination classes
• Use lpadmin command to define and modify
  characteristics of printer devices and classes
• Stop lpsched first

15
System V printing

• Adding a printer
• lpadmin p printer v special-files
  interface-option
• Where interface_option can be
• -e printer
• -m model
• -i interface-path
• Example
• lpadmin pPS4 v /dev/tty02 ePS3
• Modifying and deleting printers
• Option x removes a printer
• Option P changes a printer if it is existed.
• Managing Device class
• Use c option to place a printer into a class
• lpadmin pPS2 -claser

16
System V printing

• Adding a New printer
• Physically connect the printer
• Change the ownership of the special file to the
  user lp and change its mode to 600
• Check startup file (s file and K file)
• Make links if they do not exist
• Shutdown printing service with lpshut if running,
  and then use lpadmin to add the printer
• Start the printer and its queue
• accept PS3
• enable PS3
• Test the new printer by spooling a small file.

17
Network Printing

• Sharing printers among systems within a local
  area network
• Print server allow users on other hosts send
  jobs to one or more of its printers
• Clients send the jobs to remote hosts.
• Between BSD System
• Outgoing
• Set up printcap entry to specify
• the destination host (rm)
• The target printer (rp)
• Incoming
• Allow a remote system to print
• /etc/hosts.lpd or /etc/hosts.equiv

18
Network printing

• Remote printing under Solaris
• Outgoing
• Register the remote system name using lpsystem
• Set up a queue using lpadmin
• Incoming
• Handled by the Service Access Facility
• Configure the local listen port monitor using
  pmadm

19
Practice

• Lets configure the printer on Solaris
• Connect the printer to the network
• Set the printer IP address/netmask
• Define the printer on your Solaris box
• Use lpadmin sun as
• lpadmin p printername s systemname
• Or use /usr/sadm/admin/bin/printmgr
• Enable the printer
• Print a test page

20
Exercise

• Configure the printer on Linux with CUPS
• CUPS common Unix printing system
• Dynamic printer detection
• Broadcasts the printer available
• Grouping printers
• Integrating with Windows
• Configure it via localhost631
• Disable the queue
• Disable the printer
• Cancel a job
• Check the print queue