Printing.

17 Printing.

Steps to set up a local printer on your Unix workstation.

• Physically connect the printer to the computer (for serial ports, you may need a null modem cable)
  
• For serial line printers, create or modify an entry in the terminal line configuration file
  
• Configure the proper files on the system to communicate correctly with the proper port
  
• Create a spooling directory and accounting files for this print queue
  
• Set up proper filter programs (if necessary)
  
• Configure the printer system to allow printing to your new device
  
• Enable printing on the new device
  
• Send a print job to test the printer
  

17.1 BSD spooling.

The lpr system uses a single printer capabilities file to control printing; which device, what filter to use, baud rates, form feeds, remote host and remote device name, etc. The lpr system can work over a network.

• lpr - queues print jobs
  
• lprm - removes print jobs form queue
  
• lpq - shows jobs in print queue
  
• lpc - printer control program
  
• lpd - printer daemon
  
• /etc/printcap - printer configuration file describing all printers on this host (and possibly other remote hosts)
  
• Put entry in /etc/ttys (/etc/ttytab under SunOS 4.1.3) for serial port with status off, type unknown and keyword none.
  

17.1.1 BSD printcap file.

Here is an example /etc/printcap file Note that this is for a Postscript printer. It needs special filters to convert ordinary text into Postscript output. The software to do this, Transcript, is available free to campus systems. The Transcript install program made this printcap entry.

17.2 System V printing.

The lp system uses scripts that control the printer devices. (System V.4 adds remote printing and PostScript capabilities)

• lp - initiates print requests
  
• cancel - cancels pending print requests
  
• lpstat - to list queue contents and show status
  
• accept - allows lp to accept requests
  
• reject - prevents lp from accepting requests
  
• enable - activates named printer
  
• disable - disables named printer
  
• lpadmin - configures lp spooling system
  
• lpsched - line printer scheduling daemon
  
• /usr/spool/lp/model - directory where model files are kept
  

17.3 AIX queueing.

AIX supports the BSD and System V printer commands and adds extra functionality by integrating printing with its general queueing system.

www.washington.edu