To use a parallel port printer, the lp, parport and parport_pc kernel modules are required. To see if your USB printer is detected, make sure you have the usbutils package installed, then:īus 001 Device 007: ID 03f0:1004 Hewlett-Packard DeskJet 970c/970cse For example, if the printer is connected to a USB port, it uses the USB back-end.Īdditional steps for printer detection are listed below for various connection interfaces.

The filter converts the PDF file to a format understood by the printer.

CUPS then looks at the printer's PPD file (printer description file) and figures out what filters it needs to use to convert the PDF file to a language that the printer understands (like PJL, PCL, bitmap or native PDF).

An application sends a PDF file to CUPS when 'print' has been selected (in case the application sends another format, it is converted to PDF first).

It is important to know how CUPS works if wanting to solve related issues:

Then, whenever a program attempts to connect to one of these CUPS sockets, systemd will start rvice and transparently hand over control of these ports to the CUPS process. If cups.socket is enabled (and rvice is disabled), systemd will not start CUPS immediately it will just listen to the appropriate sockets. Then enable and start rvice or alternatively use socket activation to only start CUPS when a program wants to use the service.Ĭups provides a cups.socket unit. The location can be changed in /etc/cups/nf. By default, PDF files are stored in /var/spool/cups-pdf/ username/. Optionally, install the cups-pdf package if you intend to 'print' into a PDF document. The package is needed because IPP Everywhere sends a PDF directly to the printer, therefore cups-pdf is needed to convert everything you want to print to a PDF first. Without this package you may see an error like: client-error-document-format-not-supported. Note: As drivers are deprecated in CUPS in favor of IPP Everywhere you may need to install cups-pdf to get printing to work.

Color test print pdf