Tag Archives: printer

Manual cURL cURL

The HP Color LaserJet CP3525 Printer looks like any other ordinary printer done by HP. But there’s a difference!

A friend of mine fell over this gem, and told me.

TCP/IP Settings

If you go to the machine’s TCP/IP settings using the built-in web server, the printer offers the ordinary network configure options but also one that sticks out a little exta. The “Manual cURL cURL” option! It looks like this:

I could easily confirm that this is genuine. I did this screenshot above by just googling for the string and printer model, since there appears to exist printers like this exposing their settings web server to the Internet. Hilarious!


How on earth did that string end up there? Certainly there’s no relation to curl at all except for the actual name used there? Is it a sign that there’s basically no humans left at HP that understand what the individual settings on that screen are actually meant for?

Given the contents in the text field, a URL containing the letters WPAD twice, I can only presume this field is actually meant for Web Proxy Auto-Discovery. I spent some time trying to find the user manual for this printer configuration screen but failed. It would’ve been fun to find “manual cURL cURL” described in a manual! They do offer a busload of various manuals, maybe I just missed the right one.

Does it use curl?

Yes, it seems HP generally use curl at least as I found the “Open-Source Software License Agreements for HP LaserJet and ScanJet Printers” and it contains the curl license:

The curl license as found in the HP printer open source report.

HP using curl for Print-Uri?

Independently, someone else recently told me about another possible HP + curl connection. This user said his HP printer makes HTTP requests using the user-agent libcurl-agent/1.0:

I haven’t managed to get this confirmed by anyone else (although the license snippet above certainly implies they use curl) and that particular user-agent string has been used everywhere for a long time, as I believe it is copied widely from the popular libcurl example getinmemory.c where I made up the user-agent and put it there already in 2004.


Frank Gevaerts tricked me into going down this rabbit hole as he told me about this string.

My home setup

I work in my home office which is upstairs in my house, perhaps 20 steps from my kitchen and the coffee refill. I have a largish desk with room for a number of computers. The photo below shows the three meter beauty. My two kids have their two machines on the left side while I use the right side of it for my desktop and laptop.

Daniel's home office

Many computers

The kids use my old desktop computer with a 20″ Dell screen and my old 15.6″ dual-core Asus laptop. My wife has her laptop downstairs and we have a permanent computer installed underneath the TV for media (an Asus VivoPC).

My desktop computer

I’m primarily developing C and C++ code and I’m frequently compiling rather large projects – repeatedly. I use a desktop machine for my ordinary development, equipped with a fairly powerful 3.5GHz quad-core Core-I7 CPU, I have my OS, my home dir and all source code put on an SSD. I have a larger HDD for larger and slower content. With ccache and friends, this baby can build Firefox really fast. I put my machine together from parts myself as I couldn’t find a suitable one focused on horse power but yet a “normal” 2D graphics card that works Fractal Designfine with Linux. I use a Radeon HD 5450 based ASUS card, which works fine with fully open source drivers.

I have two basic 24 inch LCD monitors (Benq and Dell) both using 1920×1200 resolution. I like having lots of windows up, nothing runs full-screen. I use KDE as desktop and I edit everything in Emacs. Firefox is my primary browser. I don’t shut down this machine, it runs a few simple servers for private purposes.

My machines (and my kids’) all run Debian Linux, typically of the unstable flavor allowing me to get new code reasonably fast.

Func KB-460 keyboardMy desktop keyboard is a Func KB-460, mechanical keyboard with some funky extra candy such as red backlight and two USB ports. Both my keyboard and my mouse are wired, not wireless, to take away the need for batteries or recharging etc in this environment. My mouse is a basic and old Logitech MX 310.

I have a crufty old USB headset with a mic, that works fine for hangouts and listening to music when the rest of the family is home. I have Logitech webcam thing sitting on the screen too, but I hardly ever use it for anything.

When on the move

I need to sometimes move around and work from other places. Going to conferences or even our regular Mozilla work weeks. Hence I also have a laptop that is powerful enough to build Firefox is a sane amount of time. I have Lenovo Thinkpad w540a Lenovo Thinkpad W540 with a 2.7GHz quad-core Core-I7, 16GB of RAM and 512GB of SSD. It has the most annoying touch pad on it. I don’t’ like that it doesn’t have the explicit buttons so for example both-clicking (to simulate a middle-click) like when pasting text in X11 is virtually impossible.

On this machine I also run a VM with win7 installed and associated development environment so I can build and debug Firefox for Windows on it.

I have a second portable. A small and lightweight netbook, an Eeepc S101, 10.1″ that I’ve been using when I go and just do presentations at places but recently I’ve started to simply use my primary laptop even for those occasions – primarily because it is too slow to do anything else on.

I do video conferences a couple of times a week and we use Vidyo for that. Its Linux client is shaky to say the least, so I tend to use my Nexus 7 tablet for it since the Vidyo app at least works decently on that. It also allows me to quite easily change location when it turns necessary, which it sometimes does since my meetings tend to occur in the evenings and then there’s also varying amounts of “family activities” going on!


For backup, I have a Synology NAS equipped with 2TB of disk in a RAIDSynology DS211j stashed downstairs, on the wired in-house gigabit Ethernet. I run an rsync job every night that syncs the important stuff to the NAS and I run a second rsync that also mirrors relevant data over to a friends house just in case something terribly bad would go down. My NAS backup has already saved me really good at least once.


HP Officejet 8500ANext to the NAS downstairs is the house printer, also attached to the gigabit even if it has a wifi interface of its own. I just like increasing reliability to have the “fixed services” in the house on wired network.

The printer also has scanning capability which actually has come handy several times. The thing works nicely from my Linux machines as well as my wife’s windows laptop.


fiber cableI have fiber going directly into my house. It is still “just” a 100/100 connection in the other end of the fiber since at the time I installed this they didn’t yet have equipment to deliver beyond 100 megabit in my area. I’m sure I’ll upgrade this to something more impressive in the future but this is a pretty snappy connection already. I also have just a few milliseconds latency to my primary servers.

Having the fast uplink is perfect for doing good remote backups.

Router  and wifi

dlink DIR 635I have a lowly D-Link DIR 635 router and wifi access point providing wifi for the 2.4GHz and 5GHz bands and gigabit speed on the wired side. It was dead cheap it just works. It NATs my traffic and port forwards some ports through to my desktop machine.

The router itself can also update the dyndns info which ultimately allows me to use a fixed name to my home machine even without a fixed ip.

Frequent Wifi users in the household include my wife’s laptop, the TV computer and all our phones and tablets.


Ping Communication Voice Catcher 201EWhen I installed the fiber I gave up the copper connection to my home and since then I use IP telephony for the “land line”. Basically a little box that translates IP to old phone tech and I keep using my old DECT phone. We basically only have our parents that still call this number and it has been useful to have the kids use this for outgoing calls up until they’ve gotten their own mobile phones to use.

It doesn’t cost very much, but the usage is dropping over time so I guess we’ll just give it up one of these days.

Mobile phones and tablets

I have a Nexus 5 as my daily phone. I also have a Nexus 7 and Nexus 10 that tend to be used by the kids mostly.

I have two Firefox OS devices for development/work.

Back in the printing game

HP Officejet 8500AAfter my printer died, I immediately ordered a new one online and not long afterwards I could pick it up from my local post office. As I use both the scanner and the printer features pretty much I went with another “all-in-one” model and I chose an HP model (again) basically because I’ve been happy with how my previous worked (before its death). “HP Officejet Pro 8500 A910” seems to be the whole name. And yeah, it really is as black as the picture here shows it.

This model is less “photo-focused” than my previous but I never print my own photos so that’s no loss. What did annoy me was however that this model uses 4 ink cartridges instead of the 6 in my previous, but of a completely different design so I can’t even re-use my half-full ink containers from the corpse!

My new printer has some fancy features. It is one of them that I can give an email address and then print on by sending email to it. The email address then gets a really long one with lots of seemingly random letters, it is in the hp.com domain and I can set up a white-list of people (From: addresses) that is allowed to print on it via email.

It also has full internet access itself so it could fetch a firmware upgrade file and install that entirely on its own without the use of a computer. (Which made me wonder if they use libcurl, but I realize there’s no way for me to tell and of course there are many alternatives they might use.)

Driver-wise, it seems like a completely different set for Windows (hopefully this won’t uninstall itself) and on Linux I could install it fine to print, but xsane just won’t find it to scan. I intend to instead try to use the printer’s web service for scanning, hopefully that will be roughly equivalent for my limited use – I mostly scan documents, bills and invoices for my work.

And another printer died on me

My printer is dead.

HP Photosmart C6180

I got myself this HP C6180 all-in-one thing a little over three years ago and it was a good and fine printer, scanner and copier. I’ve had great use for it and it worked fine under Linux too.

Things started to decline

My problems with this printer basically started like a year ago or so when my wife’s laptop running Windows Vista suddenly decided to automatically uninstall the printer drivers. Every now and then it decides to remove the printer and I re-install it. Repeat. It gets a little boring after a while and I’ve failed to locate the reason or address the actual problem. We just re-install the driver often.

When that started happening, the HP software package for using the scanner functionality stopped working. Even if I uninstall everything and re-install etc, it just refuses to work. Possibly I could try using some other tools for scanning but since I mostly scan for my work purposes I can just as well do that from one of my computers (as opposed to my wife’s) and they run Linux and they don’t have this scanner problem.

The final blow

I scanned a paper for work (which turned to be the last useful thing I could ever do with it) and then I decided to print a short document to accompany a few receipts I had to send to the company handling Haxx‘s economy. I wrote it up in Open Office and pressed print. My home office is upstairs while the printer is downstairs so I didn’t check the printout immediately. After a while I walked down to put the paper into the envelope and notice there was no paper there. The printer had gone into a loop were it obviously powers on, starts a while (the little LCD on it starts up and shows some animation) and then it powers off and goes back on again.

First Aid

I yanked all the cables, cancelled the printer jobs from my computer, inserted the power cable again only to see the power cycle start again.

Sigh. I googled “HP c6180 reset” and landed on this great page which describes several ways that people have successfully used to hard reset their printers of exactly my model. I tried them all. Patiently one by one (including pressing 6 + #, 6 + * and OK + help when inserting the power cable). None of them made any impact, the device is still going in the power loops. As the printer is over three years old there’s no warranty or anything, and comments all over clearly indicate that HP charges for repairs of this kind of problem.

I can’t but to still have a feeling that this might be software related and then there should be some kind of master reset somewhere that would bring it back to some initial state. I just can’t find any…

Sorry dude, it’s gone

A few comments I’ve found indicate that this problem has been seen on devices with failed capacitors and there’s even a nice picture showing exactly which with a description of how to proceed to replace them. I’m just crappy with soldering and fiddling on that HW level and it’s not like I would be even close to have those spare parts.

There was nothing I could do. The poor thing is not possible to reach anymore we have to put it out of its misery!

Replacement system

Postit noteOk, I still had to mail my physical mail with receipts away so I had to pull out my backup system for emergencies like this. It is a very sophisticated concept divided into many separate yellow pieces and I’ll you show you a picture of one of them here on the left.

So the process of finding and getting a new printer/scanner has begun… I use it rather often so I’ll probably go quickly and pick something similar to what just died here.

Plenty Pointless Printer Processes

I recently got a new printer for my home network. My old Epson Photo 870 printer with a D-Link Ethernet-to-parallel port printer server thing suddenly died one day not too long ago.

HP Photosmart C6180I opted for a solution with native Ethernet support that could also work as a copier and scanner so that those (even though rather rarely needed) functions would also be dealt with nicely. (In fact fax too, but I can’t think I’ll ever use that so I haven’t bothered to connect it to the phone system.) I went with the HP C6180 thing, since seemed like a nice setup for a fairly low price. Even though I don’t necessarily plan to print to it from my Linux hosts, I did read some positive reviews about it when used from Linux with CUPS so that was another point talking for this particular model. The printer even has wifi support but I’m using wired Ethernet since it is faster and I have the printer standing next to my wifi router anyway. Also, having scanner supported would mean I can finally put away my 7 year old USB scanner that I’ve been lugging out to use on occasion.

Sometimes (or is it often?) we get to hear that the printer situation on Linux is horrible or at least far from perfect, and while I agree with that I find the situation on Windows horrible – but for entirely different reasons

I followed the printer’s user manual on how to install it on Anja‘s (my wife’s) laptop that runs Windows XP, by inserting the CD and clicking “yes – over Ethernet” etc and it went on and and installed. And wow, did it get installed!

It brought four new icons to the desktop and after the lengthy process was at the end there were at least ten new processes running in the system and for some reason they actually made an impact and the system felt slower! I had to go on a kill frenzy to clear up the worst mess. The amazing part is that even though I killed every single process starting with “HP”, everything still worked exactly like I wanted. And with “msconfig” I could also prevent some of the worst stuff to start again at next reboot… (This kind of behavior is sadly not specific for printers-only on Windows…)

I did have some initial quirks with the printer, until I set it to use a fixed IP address. I’m not sure it really had something to do with it, but I wanted fixed IP anyway and the problems seemed to vanish.