HPLIP Printer Application

INTRODUCTION

This repository contains a Printer Application for printing on HP and Apollo printers supported by HP's HPLIP driver suite.

It uses PAPPL to support IPP printing from multiple operating systems. In addition, it uses the resources of cups-filters 2.x (filter functions in libcupsfilters, libppd) and pappl-retrofit (encapsulating classic CUPS drivers in Printer Applications). This work (or now the code of pappl-retrofit) is derived from the hp-printer-app.

The printer driver itself and the software to communicate with the printer hardware is taken from the HPLIP (HP Linux Imaging and Printing) driver suite, also the Information about supported printer models and their capabilities.

Your contributions are welcome. Please post issues and pull requests.

Note: HPLIP is actively maintained by HP, they are continuously adding the newest printer models and adapting the software to new environments/Linux distributions. Therefore it would also be the correct way if HP turns HPLIP into a Printer Application or at least offers this as an alternative to the classic CUPS/SANE driver. Especially they should create a native Printer Application, meaning that it does not use PPDs, CUPS filters, and CUPS backends internally. Also their utilities need to be made independent of CUPS.

For PostScript printers you can also use the PostScript Printer Application, especially if you have it already installed for some non-HP PostScript printer.

Also check whether your printer is a driverless IPP printer (AirPrint, Mopria, IPP Everywhere, Wi-Fi Direct Print, prints from phones) as in this case you do not need any Printer Application at all. Most modern HP printers, even the cheapest models, are driverless IPP printers. Even USB-only printers can be driverless IPP, and you can generally use driverless IPP via USB, try ipp-usb for these cases first.

Properties

• A Printer Application providing the hpcups printer driver and all printer's PPDs of HPLIP, supporting printing on most printers from HP and Apollo. This allows easy printing in high quality, including photos on photo paper. The hpps CUPS filter for PIN-protected printing on PostScript printers is also included.

• The printers are discovered with HPLIP, too. For USB printers the hp CUPS backend is used and for network printers the hp-probe utility (encapsulated in a script to behave as a CUPS backend).

• The communication with the printers is done by the hp CUPS backend and so (at least in case of USB) the IEEE-1284.4 packet protocol (protocol 7/1/3 on USB) is used and not a simple stream protocol (like the standard CUPS and PAPPL backends use). This way one should be able to print and scan simultaneously, or at least check printer status while printing. Not all printers support this protocol, if not, a standard streaming protocol is used. Also any other special functionality which requires the hp backend is supported. On the "Add Printer" web interface page under "Devices" select the "HPLIP (HP)" entries.

• Note that the hp backend does not allow bi-directional access to the printer. If you have a PostScript printer and prefer support for remote querying of the printer's accessory configuration instead of simultaneous printing and scanning, CUPS' standard backends for USB and network printers are also available.

• If you have an unusal system configuration or a personal firewall HP's backends will perhaps not discover your printer. Also in this situation the standard backends, including the fully manual "Network Printer" entry in combination with the hostname/IP field can be helpful.

• Use of CUPS' instead of PAPPL's standard backends makes quirk workarounds for USB printers with compatibility problems being used (and are editable) and the output can get sent to the printer via IPP, IPPS (encrypted!), and LPD in addition to socket (usually port 9100). The SNMP backend can get configured (community, address scope).

• PWG Raster, Apple Raster or image input data to be printed on a non-PostScript printer does not get converted to PostScript or PDF, it is only converted/scaled to the required color space and resolution and then fed into the hpcups driver.

• For printing on non-PostScript printers PDF and PostScript input data is rendered into raster data using Ghostscript. Ghostscript is also used to convert PDF into PostScript for PostScript printers.

• The information about which printer models are supported and which are their capabilities is based on the PPD files included in HPLIP. They are packaged in the Snap as a compressed archive.

• Standard job IPP attributes are mapped to the driver's option settings best fitting to them so that users can print from any type of client (like for example a phone or IoT device) which only supports standard IPP attributes and cannot retrive the PPD options. Trays, media sizes, media types, and duplex can get mapped easily, but when it comes to color and quality it gets more complex, as relevant options differ a lot in the PPD files. Here we use an algorithm which automatically (who wants hand-edit ~3000 PPD files for the assignments) finds the right set of option settings for each combination of print-color-mode (color/monochrome), print-quality (draft/normal/high), and print-content-optimize (auto/photo/graphics/text/text-and-graphics) in the PPD of the current printer. So you have easy access to the full quality or speed of your printer without needing to deal with printer-specific option settings (the original options are still accessible via web admin interface).

• The Snap of the HPLIP Printer Application takes HPLIP's source code from Debian's packaging repository instead of directly from HP, as Debian's package has ~80 patches fixing bugs which are reported to HP but the patch not adopted upstream. So with the Snap users should get the same experience in reliability and quality as with the Debian package.

• Support for downloading the proprietary plugin of HPLIP via an additional page in the web interface. This adds support for some laser printers which need their firmware loaded every time they are turned on or which use certain proprietary print data formats. This works both in the Snap and in the classic installation of the Printer Application (must run as root, otherwise only status check of the plugin).

To Do

• Support for scanning on HP's multi-function printers. this requires scanning support in PAPPL (which made good progress in GSoC 2021).

• PDF test page, for example generated with the bannertopdf filter.

• Human-readable strings for vendor options (Needs support by PAPPL: Issue #58: Localization support)

• Internationalization/Localization (Needs support by PAPPL: Issue #58: Localization support)

• SNMP Ink level check via ps_status() function (Needs support by PAPPL: Issue #83: CUPS does IPP and SNMP ink level polls via backends, PAPPL should have functions for this)

• Build options for cups-filters, to build without libqpdf and/or without libppd, the former will allow to create the Snap of this Printer Application without downloading and building QPDF

THE SNAP

Installing and building

To just run and use this Printer Application, simply install it from the Snap Store:

sudo snap install --edge hplip-printer-app

Then follow the instructions below for setting it up.

To build the Snap by yourself, in the main directory of this repository run

snapcraft snap

This will download all needed packages and build the HPLIP Printer Application. Note that PAPPL (upcoming 1.0) and cups-filters (upcoming 2.0) are pulled directly from their GIT repositories, as there are no appropriate releases yet. This can also lead to the fact that this Printer Application will suddenly not build any more.

To install the resulting Snap run

sudo snap install --dangerous hplip-printer-app_1.0_amd64.snap

Setting up

The Printer Application will automatically be started as a server daemon.

Enter the web interface

http://localhost:8000/

Use the web interface to add a printer. Supply a name, select the discovered printer, then select make and model. Also set the installed accessories, loaded media and the option defaults. If the printer is a PostScript printer, accessory configuration and option defaults can also often get polled from the printer.

If the entry of your printer in the web interface has the remark "requires proprietary plugin", you need to install HP's plugin. For this, click on the "Plugin" button in this printer entry or on the "Install Proprietary Plugin" button under "Other Settings" on the front page of the web interface and follow the instructions on the screen.

Then print PDF, PostScript, JPEG, Apple Raster, or PWG Raster files with

hplip-printer-app FILE

or print with CUPS, CUPS (and also cups-browsed) discover and treat the printers set up with this Printer Application as driverless IPP printers (IPP Everywhere and AirPrint).

See

hplip-printer-app --help

for more options.

Use the "-o log-level=debug" argument for verbose logging in your terminal window.

You can add files to /var/snap/hplip-printer-app/common/usb/ for additional USB quirk rules. Edit the existing files only for quick tests, as they get replaced at every update of the Snap (to introduce new rules).

You can edit the /var/snap/hplip-printer-app/common/cups/snmp.conf file for configuring SNMP network printer discovery.

BUILDING WITHOUT SNAP

You can also do a "quick-and-dirty" build without snapping and without needing to install PAPPL, cups-filters 2.x, and pappl-retrofit into your system. You need a directory with the latest GIT snapshot of PAPPL, the latest GIT snapshot of cups-filters, and the latest GIT snapshot of pappl-retrofit (master branches of each). They all need to be compiled (./autogen.sh; ./configure; make), installing not needed. Also install the header files of all needed libraries (installing "libcups2-dev" should do it).

In the directory with hplip-printer-app.c run the command line

gcc -o hplip-printer-app hplip-printer-app.c $PAPPL_SRC/pappl/libpappl.a $CUPS_FILTERS_SRC/.libs/libppd.a $CUPS_FILTERS_SRC/.libs/libcupsfilters.a $PAPPL_RETROFIT_SRC/.libs/libpappl-retrofit.a -ldl -lpthread  -lppd -lcups -lavahi-common -lavahi-client -lgnutls -ljpeg -lpng16 -ltiff -lz -lm -lusb-1.0 -lpam -lqpdf -lstdc++ -I. -I$PAPPL_SRC/pappl -I$CUPS_FILTERS_SRC/ppd -I$CUPS_FILTERS_SRC/cupsfilters -I$PAPPL_RETROFIT_SRC/pappl/retrofit -L$CUPS_FILTERS_SRC/.libs/ -L$PAPPL_RETROFIT_SRC/.libs/

There is also a Makefile, but this needs PAPPL, cups-filters 2.x, and pappl-retrofit to be installed into your system.

Run

./hplip-printer-app --help

When running the non-snapped version, by default, PPD files are searched for in

/usr/share/ppd/
/usr/lib/cups/driver/
/var/lib/hplip-printer-app/ppd/

You can set the PPD_PATHS environment variable to search other places instead:

PPD_PATHS=/path/to/my/ppds:/my/second/place ./hplip-printer-app server

Simply put a colon-separated list of any amount of paths into the variable. Creating a wrapper script is recommended.

Note that only PPD files for the hpcups driver of HPLIP are considred, other PPD files are ignored.

Printers are only discovered via the hp backend of HPLIP (USB) or the hp-probe utility of HPLIP (network). For the latter a wrapper script named HP is included which makes the utility be used like a CUPS backend (discovery mode only). This especially makes only HP and Apollo printers being discovered. Printers from other manufacturers are not supported.

Jobs are filtered through hpcups and send to the printer via the hp backend (both USB and network).

The standard (not HPLIP's) backends provided as alternative in this Printer Application are CUPS' backends and not PAPPL's, meaning that for USB printers CUPS' USB quirk workarounds for compatibility problems are used, network printers can also be used with IPP, IPPS, and LPD protocols, and SNMP printer discovery is configurable.

USB Quirk rules in /usr/share/cups/usb and the /etc/cups/snmp.conf file can get edited if needed.

Make sure you have HPLIP installed and if you want to use standard backends, CUPS (at least its backends).

You also need Ghostscript to print PDF or PostScript jobs.

For access to the test page testpage.ps use the TESTPAGE_DIR environment variable:

TESTPAGE_DIR=`pwd` PPD_PATHS=/path/to/my/ppds:/my/second/place ./hplip-printer-app server

or for your own creation of a test page (PostScript, PDF, PNG, JPEG, Apple Raster, PWG Raster):

TESTPAGE=/path/to/my/testpage/my_testpage.ps PPD_PATHS=/path/to/my/ppds:/my/second/place ./hplip-printer-app server

LEGAL STUFF

The HPLIP Printer Application is Copyright © 2020 by Till Kamppeter.

It is derived from the HP PCL Printer Application, a first working model of a raster Printer Application using PAPPL. It is available here:

https://github.com/michaelrsweet/hp-printer-app

The HP PCL Printer Application is Copyright © 2019-2020 by Michael R Sweet.

This software is licensed under the Apache License Version 2.0 with an exception to allow linking against GPL2/LGPL2 software (like older versions of CUPS). See the files "LICENSE" and "NOTICE" for more information.