Transcript COP 4343
COP 4343 Unix System Administration Unit 9: printing – lpr – CUPS 1 Printing in Unix • Traditional – Berkeley Line Printer Daemon – AT&T Line Printer System • Improvements: – typical Linux implementation – LPRng • Emerging standard – Internet Printing Protocol: IPP/1.1 – Common Unix Printing System: CUPS 2 Traditional Linux printing • PRINTER environment variable • command line printing: lpr ex: lpr filename • print job maintenance – show print queue: lpq – remove job from queue: lprm 3 lpd daemon • configuration – /etc/printcap • local or remote printers – print filters • queue control per printer – lpc • status, start, stop 4 Common Unix Printing System • CUPS manages printers in a network – maintains printer definitions – allows printing to network printers • maintains lpr commands and /etc/printcap file for backward compatibility 5 CUPS device support lpinfo -v network socket network http network ipp network lpd network smb serial serial:/dev/ttyS2?baud=115200 direct parallel:/dev/lp1 direct usb:/dev/usb/lp0 direct scsi direct hal 6 CUPS setup • cups service – yum install cups – enable in run-level: chkconfig cups on – start service: service cups start • configuration – /etc/cups/cupsd.conf • specify which IP:port to listen on listen on 127.0.0.1:631 • allow access to Location / and /admin allow from 127.0.0.1 – security: allow tcp port 631 in firewall 7 Common Unix Printing System • managing CUPS printers – command line interface: lpadmin – old style semi-graphical: • printconf – web interface on port 631 http://localhost:631/admin • printer definitions – ppd files 8 CUPS printer setup • printer class – for sets of similar printers – jobs accepted to class will print on one printer in class • printer setup – local: device – network: protocol + host + name • ex: “lpd://ferret.cs.fiu.edu/venom” 9 CUPS printer setup • supported printers – HP, Epson, Okidata, Postscript, ... • printer options – output resolution, double-sided, banner, ... 10 CUPS printing • client – PRINTER environment variable – interactive from program • • • • lpr or lp lpq lprm lpstat 11