Distribution quote of the week [LWN.net]

Modern (>2010) networked printers JustWork(tm), without need for local drivers. CUPS-shared printers JustWork(tm), also without local drivers. Folks with smartphones can print to most CUPS-attached printers, again, no drivers.
We have a standard _lossless_ raster image format that all printers must accept. We have a native PDF-based print flow, enabling far more consistent rendering behavior than pure postscript, as well as a much richer set of capabilities.
We have end-to-end colorspace awareness, with automatic colorspace conversion if the appropriate profiles are installed. We have sane auto-scaling/cropping modes that generally do the right thing in the face of aspect ratio mismatches.
We're closer than ever to a universal printing system that is not tied to any specific OS or client, and that behaves identically no matter where or how the printer is attached. Underpinning all of this are formally standardized protocols (and equally importantly, well-defined behaviors), Free Software reference implementations and conformance tests.
Of course we also have bugs galore, because it's software.

— Solomon Peachy

Linux distributions on smartphones are here to stay!

— postmarketOS blog

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Distribution quote of the week - network printing protocols

Posted May 27, 2021 11:43 UTC (Thu) by MortenSickel (subscriber, #3238) [Link] (2 responses)

Solomon Peachy talks about bidirectional communication between printers and PCs, which is nice - and can be misused. I recently bought a second hand relatively new HP printer and plugged it into my home network. My linux PCs found it and could use it without any further ado, one of the Win10 PCs in the household had no problems, another win 10 PC found it,connected and refused to print...

After a lot of debugging and pulling out my (already) grey hair, I found the reason. The one PC that refused to print had never before been connected to a printer at our network,so when I set it up, it found the printer and set up a low level bi directional communication. That was used by the printer to tell the PC that "I am so low on toner that I am not able to print anything any longer, so just leave me alone" - whereas the other Win10 PC had been earlier connected to another printer that had lived at the same IP and reused the old connection settings, thereby disabling the channel the printer could use to complain... After setting up the one that refused to print to use a simpler protocol, it has worked great...

(and looking at the settings at the printer, it should start to complain about low toner and presumtably refuse to print at <10% left - in a 6000 pages toner cassette... :-/ )

Distribution quote of the week - network printing protocols

Posted May 27, 2021 12:45 UTC (Thu) by farnz (subscriber, #17727) [Link]

The HP LaserJet I have allows you to override that signal - you have to tell the printer that you're OK printing on low toner (can't remember where in the web UI that's found), and then it'll happily attempt to print while toner is low.

Distribution quote of the week - network printing protocols

Posted May 27, 2021 13:49 UTC (Thu) by pizza (subscriber, #46) [Link]

In fairness, this problem came about due to how Windows talks to printers -- the subsystem can only talk to local "ports" (of the old-school parallel/serial variety) To speak to anything more modern, it a virtual "port" is created that is tied to a network endpoint or USB device.

The driver for this virtual port is often manufacturer/model-specific, but from the outside, the printing subsystem can only tell that PORTX == URI. So if you didn't uninstall the old printer (&|driver) properly, that virtual port stays behind, and since from Windows' perspective it's the same URI, the old port gets re-used. With predictable hair-pulling results.

(and URI can be an IP address+port, an actual ipp:// uri, or whatever....)

Distribution quote of the week

Posted May 27, 2021 23:19 UTC (Thu) by swilmet (guest, #98424) [Link] (2 responses)

About printing, my only complaint is not about CUPS, but about more and more documentation *not* being available in a format suitable for printing (PDF, or a single-page HTML). The trend is these modern documentation websites, split into many webpages, without counting the recurrent struggle to print a webpage that was not designed with printing in mind.

It's becoming rarer and rarer the software systems that provide documentation in multiple formats : multi-page HTML, single-page HTML, PDF, EPUB, … If you want your software system to be better known, with more people learning it, having the documentation in multiple formats (including at least one printing-to-paper-friendly format) can greatly help.

Documentation scales! Even if you don't know it, it is read, and some software developers silently do useful work with it, without feeling the need to ask questions to the community.

Distribution quote of the week

Posted May 28, 2021 1:56 UTC (Fri) by calumapplepie (guest, #143655) [Link] (1 responses)

It's not as hopeless as it may seem. Docs are usually made with generators, and for a good open-source project, the source of those docs is available as well. If you can get to the document sources, you can probably generate something printable. Also, many of these sites do provide something downloadable: readthedocs.org, for instance, generates single-page HTML and PDF formats for all docs.

When it comes to proprietary docs, well....

Distribution quote of the week

Posted May 28, 2021 7:39 UTC (Fri) by swilmet (guest, #98424) [Link]

Recently I ended up printing the documentation source files directly, when it's in a lightweight format like Markdown it's readable and it contains relative links to other pages.