CUPS printing overview

On Linux, the CUPS printing system consists of the following elements:

cupsd

This daemon is started at boot time and runs continuously, listening for print requests directed at multiple printers. When a job is submitted to a print queue, cupsd handles jobs on that queue. The copy exits when the queue is emptied.

/etc/cups/cupsd.conf

This file configures the cupsd daemon. It is normally located in the /etc/cups directory.

Each line in the file can be a configuration directive, a blank line, or a comment. The configuration directives are intentionally similar to those used by the popular Apache web server software.

/etc/cups/printers.conf

This file defines available local printers. It is generated automatically by cupsd when printers are added, deleted, or changed. This file shouldn’t be changed manually.

/etc/printcap

This file is still present on the system to allow older printing applications that rely on it to keep functioning. Under CUPS, the file is automatically generated by cupsd from the /etc/cups/printers.conf file. All changes to the file are lost if the CUPS service is restarted.

lp

The lp (line print) program submits both files and information piped to its standard input to print queues.

lpq

This program queries and displays the status and contents of print queues.

lprm

This program removes print jobs from print queues.

lpadmin

This program configures printer and class queues provided by CUPS. It can also be used to set the server default printer or class.

lpc

Nowadays, ...

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