Shallow Thoughts : tags : cups

Using a Driverless Printer on Debian (Without Avahi)

It's nice to be back on a relatively minimal Debian install, instead of Ubuntu-with-everything. But one thing that I have to admit I appreciated about Ubuntu: printing "just worked". Turn on a printer, call up the print menu in any app, and the printer I turned on would be there in the menu, without any need of struggling with CUPS configurations.

Ubuntu was using Avahi, the Linux version of Apple's Zeroconf/Bonjour framework, to discover printers. I knew that I'd probably need to install Avahi if I wanted easy printer configuration on Debian. But as it turned out, getting printing working was both harder, and easier.

Read more ...

Tags: linux, debian, cups, printing
[ 18:14 Feb 11, 2022    More linux | permalink to this entry | ]

Tricks for Installing a Laser Printer on Linux in CUPS

(Wherein I rant about how bad CUPS has become.)

I had to set up two new printers recently. CUPS hasn't gotten any better since the last time I bought a printer, maybe five years ago; in fact, it's gotten quite a bit worse. I'm amazed at how difficult it was to add these fairly standard laser printers, both of which I'd researched beforehand to make sure they worked with Linux.

It took me about three hours for the first printer. The second one, a few weeks later, "only" took about 45 minutes ... at which point I realized I'd better write everything down so it'll be faster if I need to do it again, or if I get the silly notion that I might want to print from another computer, like my laptop.

I used the CUPS web interface; I didn't try any of the command-line tools.

Figure out the connection type

In the CUPS web interface, after you log in and click on Administration, whether you click on Find New Printers or Add Printer, you're faced with a bunch of identical options with no clue how to choose between them. For example, Find New Printers with a Dell E310dw connected shows:

Available Printers

• [Add This Printer] Virtual Braille BRF Printer (CUPS-BRF)
• [Add This Printer] Dell Printer E310dw (Dell Printer E310dw)
• [Add This Printer] Dell Printer E310dw (Dell Printer E310dw)
• [Add This Printer] Dell Printer E310dw (Dell Printer E310dw (driverless))

What is a normal human supposed to do with this? What's the difference between the three E210dw entries and which one am I supposed to choose? (Skipping ahead: None of them.) And why is it finding a virtual Braille BRF Printer?

The only way to find out the difference is to choose one, click on Next and look carefully at the URL. For the three E310dw options above, that gives:

• dnssd://Dell%20Printer%20E310dw._ipp._tcp.local/?uuid=[long uuid here]
• lpd://DELL316BAA/BINARY_P1
• ipp://DELL316BAA.local:631/ipp/print

Again skipping ahead: none of those are actually right. Go ahead, try all three of them and see. You'll get error messages about empty PPD files. But while you're trying them, write down, for each one, the URL listed as Connection (something like the dnssd:, lpd: or ipp: URLs listed above); and note, in the driver list after you click on your manufacturer, how many entries there are for your printer model, and where they show up in the list. You'll need that information later.

Download some drivers

Muttering about the idiocy of all this -- why ship empty drivers that won't install? Why not just omit drivers if they're not available? Why use the exact same name for three different printer entries and four different driver entries? -- the next step is to download and install the manufacturer's drivers. If you're on anything but Redhat, you'll probably either need to download an RPM and unpack it, or else google for the hidden .deb files that exist on both Dell's and Brother's websites that their sites won't actually find for you.

It might seem like you could just grab the PPD from inside those RPM files and put it wherever CUPS is finding empty ones, but I never got that to work. Much as I dislike installing proprietary .deb files, for both printers that was the only method I found that worked. Both Dell and Brother have two different packages to install. Why two and what's the difference? I don't know.

Once you've installed the printer driver packages, you can go back to the CUPS Add Printer screen. Which hasn't gotten any clearer than before. But for both the Brother and the Dell, ipp: is the only printer protocol that worked. So try each entry until you find the one that starts with ipp:.

Set up an IP address and the correct URL

But wait, you're not done. Because CUPS gives you a URL like ipp://DELL316BAA.local:631/ipp/print, and whatever that .local thing is, it doesn't work. You'll be able to install the printer, but when you try to print to it it fails with "unable to locate printer".

(.local apparently has something to do with assuming you're running a daemon that does "Bonjour", the latest name for the Apple service discovery protocol that was originally called Rendezvous, then renamed to Zeroconf, then to Bonjour. On Linux it's called Avahi, but even with an Avahi daemon this .local thing didn't work for me. At least it made me realize that I had the useless Avahi daemon running, so now I can remove it.).

So go back to Add Printer and click on Internet Printing Protocol (ipp) under Other network printers and click Continue. That takes you to a screen that suggests that you want URLs like:

http://hostname:631/ipp/
http://hostname:631/ipp/port1

ipp://hostname/ipp/
ipp://hostname/ipp/port1

lpd://hostname/queue

socket://hostname
socket://hostname:9100

None of these is actually right. What these printers want -- at least, what both the Brother and the Dell wanted -- was ipp://printerhostname:631/ipp/print

printerhostname? Oh, did I forget to mention static IP? I definitely recommend that you make a static IP for your printer, or at least add it to your router's DHCP list so it always gets the same address. Then you can make an entry in /etc/hosts for printerhostname. I guess that .local thing was supposed to compensate for an address that changes all the time, which might be a nifty idea if it worked, but since it doesn't, make a static IP and use it in your ipp: URL.

Choose a driver

Now, finally! you can move on to choosing a driver. After you pick the manufacturer, you'll be presented with a list that probably includes at least three entries for your printer model. Here's where it helps if you paid attention to how the list looked before you installed the manufacturer's drivers: if there's a new entry for your printer that wasn't there before, that's the non-empty one you want. If there are two or more new entries for your printer that weren't there before, as there were for the Dell ... shrug, all you can do is pick one and hope.

Of course, once you manage to get through configuration to "Printer successfully added", you should immediately run Maintenance->Print Test Page. You may have to power cycle the printer first since it has probably gone to sleep while you were fighting with CUPS.

All this took me maybe three hours the first time, but it only took me about 45 minutes the second time. Hopefully now that I've written this, it'll be much faster next time. At least if I don't succumb to the siren song of thinking a fairly standard laser printer ought to have a driver that's already in CUPS, like they did a decade ago, instead of always needing a download from the manufacturer.

If laser printers are this hard I don't even want to think about what it's like to install a photo printer on Linux these days.

Tags: linux, printing, cups, rant
[ 16:19 Jan 25, 2018    More linux | permalink to this entry | ]

Helpful CUPS error messages, decoded

Another in the continuing series of "This isn't documented anywhere and Google searches aren't helpful":

Dave's printer was failing to print on Ubuntu Lucid. The only failure mode: pages came out with the single printed line,

Unable to open the initial device, quitting.

What a great, helpful error message! Thanks, CUPS!

Web searching found lots of people using HP printers, using various versions of the HPLIP software to installer newer drivers and otherwise reconfigure their HP setups.

Only problem: this printer isn't an HP. It's a Brother HL2070N, which has given very good service and, until now, worked flawlessly with every OS we've tried including Linux.

The solution? It turns out the problem really is HPLIP -- even if the printer isn't an HP. What this message really meant was:

HPLIP isn't installed, and Ubuntu's CUPS refuses to work without it.

apt-get install hplip hplip-data got the printer working again.

Wouldn't it be nice if CUPS bothered to print error messages that gave some hint of the real problem? Ideally, visible on the computer to the user, rather than on the printed page, so you don't have to waste 25 pages of dead tree while you try to narrow down the problem?

Update: After further testing, we have established that a standard Gnome-based Ubuntu Lucid machine needs hplip and hplip-data installed, while a Lucid machine without Gnome needs those two plus hpijs. Or you can get around needing any of them by ignoring CUPS' recommendation for which driver to use, and choosing the Gutenprint driver in the CUPS configuration screens.

A reader asked me if we had checked the CUPS error log. On one machine, the log file was virtually empty; on another, there actually were some lines about hpijs (nothing about hplip), intermixed with a lot of debug chatter and a large number of errors that were fairly clearly unrelated to anything we were doing.

Tags: linux, printing, cups
[ 22:46 Jun 22, 2010    More linux | permalink to this entry | ]