Radio Free Meredith

Is it, now.

clonearmy@gmail.com — Tue, 29 Dec 2009 04:00:46 GMT

According to the official Hulu.com channel on YouTube:

(image links to page where I found it; let's see how long that lasts...)

For there are strange objects in the great abyss

clonearmy@gmail.com — Mon, 28 Dec 2009 09:47:28 GMT

Via Jeff Atwood at Coding Horror, The C Programming Language by Brian W Kernighan and Dennis M Ritchie and HP Lovecraft. My favourite part:

I had heard tales of the... thing that C.A.R. Hoare had summoned up in '62– dark hints of choosing one element from an array, and partitioning the rest into lesser and greater sets, and hellishly recursing until the data were twisted into a sorted list– but nothing I could have imagined would be in any way comparable to the daemoniac, blasphemous reality that I saw.

I think any second-semester sophomore encountering quicksort for the first time knows exactly how the narrator feels.

Unrelatedly, was woken by the postman this morning from a dream in which I was giving a talk about error-correcting codes, failures in spoken communication, and formality of register, at a feminist conference (!), using the OSI network stack as an analogy (!!). I had just got through the obvious parts about how explicit, simple protocols and robust error-correction at the application layer reduce misinterpretation (for some reason, my example for that was a bingo game), but when the protocol has no built-in error correction and can be fragmented, the rate of confusion rises (I think where I was going with that was some kind of analogy between natural language and fragmented IP datagrams), but then the doorbell woke me up.

Languages I have had to invoke Greenspun's tenth rule on

clonearmy@gmail.com — Sun, 20 Dec 2009 16:35:00 GMT

clonearmy@gmail.com — Wed, 16 Dec 2009 12:41:14 GMT

Oh, hey, it's snowing.

Santa Claus and more Santa Claus

clonearmy@gmail.com — Mon, 14 Dec 2009 10:54:50 GMT

One of the cooler things about living in Belgium is that it is basically impossible to live in a reasonably-sized town and not be within a couple of blocks of a bakery. (We're a block from one, and within four blocks of two more.) This has had a really positive impact on my life in terms of breakfast. Every morning, post-caffeine, I hike over to our nearest bakery, which is also a candy shop, and pick up a bunch of fresh pastries to start enochsmiles' and my day.

This morning, the baker -- a short, apple-cheeked woman who in thirty years will look like every cartoon Mrs. Claus you've ever seen -- was laying out a tray of Santa-shaped chocolates as I walked in. "Oh, Sinterklaas?" I asked. "Nee," said the baker. "Kerstman!" This threw me, since I knew that the English "Santa Claus" is a borrowing of the Dutch "Sinterklaas", which of course is a contraction of "Sint-Nicolaas" (St. Nicholas). Come to find out, after Anglophone culture borrowed Sinterklaas and morphed him into Santa Claus, Dutch (and, by extension, Belgian) culture borrowed him right back as Kerstman ("Christmas man"). So now we have two St. Nicholases (Nicholi?), one who brings presents on December 5th, one who brings presents on December 25th.

Super brief library review

clonearmy@gmail.com — Thu, 10 Dec 2009 01:24:05 GMT

libevent is the second best thing that has ever happened to me. If you are doing asynchronous programming of any kind whatsoever¹, you should be using libevent or an appropriate interface to it.

(The first best thing that's ever happened to me? Diverting a long walk through Iowa City with ylla into the gym so that she could use the bathroom there. While waiting for her to finish up, I randomly found a newspaper and flipped through the classifieds, which led to me finding an ad for an internship at Integrated DNA Technologies, which I applied for and got; that led to me presenting at CodeCon, which led to my meeting enochsmiles and a bunch of other awesome people who have improved my life considerably, including, appropriately enough, one of the authors of libevent.)

¹Ok, fine, maybe not AJAX.

clonearmy@gmail.com — Sun, 29 Nov 2009 21:19:17 GMT

I did not know that there were so many alternative lyrics to Frère Jacques out there, including ones in many different languages.

added to this week's reading list

clonearmy@gmail.com — Sun, 22 Nov 2009 03:47:36 GMT

Max Weber's The Protestant Ethic and the Spirit of Capitalism, recommended by shabda and available free on the web from the University of Virginia.

On that note, what's a good serious economic analysis of post-scarcity systems? This reading list is rather long, but also dates to 2000, and a lot has happened between then and now. Soddy's Wealth, Virtual Wealth and Debt looks like required reading, especially these days, but only has bearing on what I'm looking for. Also, emphasis on serious; goshwow predictions and wouldn't-it-be-neat-if have their place, but Vernor Vinge, Cory Doctorow and Murray Bookchin are all too handwavy.

scenes from my living room

clonearmy@gmail.com — Sat, 21 Nov 2009 17:16:12 GMT

(SCENE: the couch. SASHA, the cat, is asleep across my forearms while I code.)

(maradydd frees an arm from under the cat and pops open a can of Red Bull.)
RED BULL CAN: *crrrack*
SASHA: Mrap!
(SASHA wakes up and starts nosing at the can, with intent.)
maradydd: Sasha. You're a cat. Cats don't need caffeine.
SASHA, attempting to bite the bottom of the can: Ack mrack.
maradydd: No. You don't get Red Bull because you don't have opposable thumbs to open the can with.
SASHA: Hrrrf. *gives up and lies down again*

Living in the future

clonearmy@gmail.com — Tue, 17 Nov 2009 01:24:13 GMT

An enterprising open-source hacker who goes by the moniker Famulus, using polywell plasma confinement, has achieved desktop-scale nuclear fusion.

There are some really lovely photos of plasmas and lab equipment on the blog, and all the STL files for the polywell itself, plus Ruby source code for running the thing, are available on github. Go to.

ETA: That's fusion full stop, not "a sustained fusion reaction producing more energy than is consumed by plasma containment". I'd wager my left temporal lobe that he's running at a net energy loss. However, polywell confinement is one of the more promising technologies out there for net-gain fusion; interested parties should check out the work that EMC2 Fusion is doing.

yippie-ki-yay, motherfuckers!

clonearmy@gmail.com — Sat, 14 Nov 2009 16:56:56 GMT

In my email this morning:

Dear Meredith Patterson,

I am delighted to inform you that your submission
127 - PKI Layer Cake: New Collision Attacks Against the Global X.509 Infrastructure
has been accepted to appear as a FULL PAPER at FC 2010.

Out of 130 submissions we accepted 19 as FULL papers (acceptance
rate: 14.6%) and 15 as SHORT papers (acceptance rate: 26.1%).

It's shepherded, meaning that we get to do some back-and-forth with an editor to beat some of the rougher bits of the paper into shape, but that is totally okay. I'll post publicly with a link to the tech-report version once the camera-ready is done, which will be no later than 15 December.

Mad props to my coauthors, Dan Kaminsky and Len Sassaman. Now, if you'll pardon me, I'm going to go dig that bottle of champagne out of the back of the fridge -- this is the most competitive conference I've ever been accepted to.

Well, shit.

clonearmy@gmail.com — Mon, 09 Nov 2009 14:25:16 GMT

By way of ernunnos, the dollar is now the currency of choice for carry trades.

View Poll: #1482906

Waking up is hard

clonearmy@gmail.com — Wed, 04 Nov 2009 22:02:05 GMT

(SCENE: our bedroom, this morning)
maradydd: Sweetie, it's time to get up. You've got a doctor's appointment this morning.
enochsmiles, not opening eyes: Can't the doctor come here?
maradydd, suppressing giggles: No, sweetie, he doesn't do that. It's time to drink a Red Bull.
enochsmiles, still not opening eyes: Can't the doctor drink a Red Bull?
maradydd: No, baby. C'mon, open your eyes...
enochsmiles: Will we play chess?
maradydd: While wearing cheese pants?
enochsmiles: You have cheese?
(at this point I picked him up bodily, and he woke up)

C'mon, guys, it isn't 1989 anymore

clonearmy@gmail.com — Mon, 02 Nov 2009 21:43:38 GMT

Those screams of rage you heard over the last few hours were me relocating several hundred inline-declared variables to the top of their scope in order to convince a library to compile under Visual Studio. And that was after I spent half an hour finding out that "error C2143: syntax error : missing ';' before 'type'" means that a variable was declared inline. Thanks a whole fucking lot, Microsoft.

Some day I will find the person whose decision it was to make VS2005's C compiler enforce the C89 standard and refuse C99. When he's discovered lying in a dark alley with a dozen copies of Kernighan and Ritchie's The C Programming Language forced down his throat, well, y'all will know who to send the cops after.

Experimental cooking awesome

clonearmy@gmail.com — Mon, 02 Nov 2009 15:50:08 GMT

Sometimes when I'm hungry but don't feel like making anything complicated, I'll whip up a batch of fry bread. It's one of the simplest things I know how to make, consisting of a 16:2:1 ratio by volume of flour, shortening (or other non-dairy hard fat, e.g. lard or coconut oil) and baking powder, with a dash of salt for every tablespoon of baking powder. (Blend dry ingredients well, work in shortening, knead in some water until dough sticks together, knead till smooth, make into fist-sized balls, squish balls flat, fry in oil till golden brown on both sides, drain and serve.) As it's such a simple recipe, it lends itself well to being a carrier for other flavours; you can add shredded cheese, herbs, crumbled bacon, or pretty much anything savoury and not too wet to the dough, or you can serve the plain breads with jam, molasses, maple syrup, chocolate sauce, or just about anything sweet. Also they keep for days and you can warm them in the oven or, if you've just woken up and are too bleary to work the oven, on the radiator.

Today's experiment was a simple one: while frying, add a couple of dashes of Worcestershire sauce to the hot oil. I was frying in a blend of olive and coconut oil (ran out of olive oil -- I know, I know, inexcusable), and did not expect the Worcestershire sauce to cause the oil to foam, which was a little startling. However, it did not foam over, and I am pleased to report that the sauce adds a very pleasant tamarind-and-anchovy tang to the crust which goes very well with the ginger tea I am drinking right now. Next time I find a ridiculously sharp Cheddar, I'm going to try grating it extremely fine, adding it to the dough with some rosemary, and doing the Worcestershire trick again.

Busted!

clonearmy@gmail.com — Mon, 02 Nov 2009 13:32:52 GMT

The obvious text-mining homework I posted about yesterday is in fact an assignment for the Pattern Processing course at the University of Sheffield, as confirmed by one of the professors for the course. Somebody's going down.

How can you tell that the end of the semester is coming up?

clonearmy@gmail.com — Sun, 01 Nov 2009 00:44:00 GMT

Because the rent-a-coder websites become clogged with bullshit requests like this and this.

Protip: if you're so incompetent that you have to outsource your homework assignments to an Indian codemonkey for $50 a pop, maybe CS is not the major for you.

Imagine what I could do with one of these

clonearmy@gmail.com — Tue, 27 Oct 2009 10:05:04 GMT

Well, I know what I want for Christmas now.

It would be so cool if McMaster.com had a wishlist feature like Amazon's. Absent that, however, I really ought to check out wishlistr and pop all the parts into that.

Foot, meet gun

clonearmy@gmail.com — Sun, 25 Oct 2009 05:15:25 GMT

Google Analytics does some pretty cool stuff, but has one major drawback for mobile web application developers: it's Javascript-based, meaning that hits from mobile devices that don't speak Javascript silently go untracked. Recently, the Analytics team released some code that does server-side tracking; the linked ZIP file contains source and examples in ASP, JSP, PHP and Perl. Why not Python, you might wonder? I wondered too, particularly since an AppEngine project I'm working on is at least somewhat intended for phones (hey, you never know when you might be away from your desk but really want to know if a certain BioBrick exists), so I did a little poking around to see if it was possible to instrument an AppEngine application using server-side Mobile Analytics.

So, the core of the Analytics server-side code is a routine that calls out to www.google-analytics.com/__utm.gif?[a bunch of parameters] and renders a 1x1 GIF as a web-bug. At first glance, this seems pretty straightforward: write a handler that makes the call to Google's web-bug and produces the $your-server web-bug. AppEngine even supports a subset of the Python Imaging Library, which means that you can build the web-bug programmatically in much the same way as the PHP/Perl/&c code does (although AppEngine's subset of PIL doesn't actually speak GIF, only JPG and PNG, so you have to render a PNG instead). Porting the samples from PHP was easy enough, with occasional references to the Perl to clarify things. (I still can't write Perl, but I can read it relatively well. So much for it being a write-only language!) However, I was surprised to find that the call out to Google's web-bug failed. What was going on there?

I dropped into the interpreter and tried a simple httplib call. No dice; it came up 404. Given that Google's using successful hits to this URL in order to register hits, that was no good -- it meant that requests from my web-bug were simply vanishing into the ether. However, placing the same request from a web browser retrieved the image just fine. What was going on there?

To find out, I opened up wireshark, reissued the request from my browser, and beheld the details of a packet with many lovely headers:

GET /__utm.gif?utmwv=utmac=MO-11263623-1&utmwv=4.4sp&utmip=&utmn=1277580264&utmhn=localhost&utmp=http%3A%2F%2Fmaradyddtestapp.appspot.com%2F&utmr=-&utmcc=__utma%253D999.999.999.999.999.1%253B&utmvid=0x01234567890abcdef HTTP/1.1
Host: www.google-analytics.com
Connection: keep-alive
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/532.2 (KHTML, like Gecko) Chrome/4.0.222.5 Safari/532.2
Cache-Control: max-age=0
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Encoding: gzip,deflate
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
If-Modified-Since: Wed, 21 Jan 2004 19:50:30 GMT

Replicating this request, headers and all, in the interpreter gave me back a 200 OK. Time for some differential diagnosis: what headers were optional, and which ones couldn't it live without?

As luck would have it, I struck gold on the first try -- passing every header except the Host header resulted in the 404 I'd gotten earlier. As long as the Host header was in the request, everything was fine. In fact, passing nothing but the request-body and the Host header worked perfectly ... in the interpreter. In AppEngine, not so much.

See, AppEngine does a lot of sandboxing, for security purposes. To this end, they've rolled their own versions of a lot of Python standard library modules, including httplib and urllib (and, I expect, anything that involves a network socket). Part of this sandboxing involves stripping "untrusted" headers from any network request generated by AppEngine code -- including Host. Ha ha!

Except ... Host is a mandatory header in HTTP 1.1. It can be empty, but it has to be there. They're supposed to return 400 Bad Request, not 404 Not Found, if no Host header is present at all ... but surely they wouldn't have a URL fetcher that was so badly standards-nonconforming as to fail to send a required header?

Well, actually, they don't, which is always nice. url_fetch.py does in fact set the Host header, right there on line 170. And this is where things get weird.

See, the error that was showing up in the AppEngine logs wasn't a 404 Not Found -- it was a -2, 'Name or service not known'. If that doesn't sound like an HTTP error to you, you're right: it's a DNS error.

Those of you scratching your heads may now scratch them harder: swap out 'www.google-analytics.com' for whatever IP address you get when you dig that hostname, and it still fails. There is absolutely no reason for DNS to be involved, because there is nothing for it to have to resolve, and yet we get back a DNS resolution error, on both the dev server and on appspot.com (so it's not an issue with my /etc/hosts, which was my first thought).

Oh, but I can fetch other stuff -- f'rinstance, the front page of this-here blog -- just fine. No trouble whatsoever. How ya like them apples?

So, for the time being, I'm not sure whether Analytics has shot AppEngine in the foot or vice versa, but someone sure is gimping around saying "ow" a lot.

The most horrible case of operator overloading I've ever heard of

clonearmy@gmail.com — Wed, 21 Oct 2009 01:37:06 GMT

Oh, don't get me wrong, I laughed, but it's horrible:

I once saw a C++ filesystem driver that overrode the / operator to mean "append". So you could do something like:
directory = "/tmp/subdir1";
filename  = "myfile.txt";
full_path = directory/filename;
and end up with full_path being "/tmp/subdir1/myfile.txt"

And no, Stroustrup's not going to hell for designing a language that lets people do this. The sheer fact that people can do this means he's already there. And so are we.

Furball in a fur bowl

clonearmy@gmail.com — Mon, 19 Oct 2009 12:55:13 GMT

Man, I feel tired just looking at him.

A bill I have a hard time imagining anyone objecting to

clonearmy@gmail.com — Fri, 16 Oct 2009 16:22:08 GMT

Via mellowtigger, up before Congress this session we have H.R. 3501, the Humanity and Pets Partnered Through the Years Act. It's super short -- you can read it in the time it takes me to explain it -- but I'll summarize anyway: if this bill passes, if you itemise deductions you can deduct pet care expenses up to $3500. This means vet bills, food, litter, a cage, &c for your cat, dog, bird, lizard, fish, hedgehog, whatever -- it just has to be domesticated and alive. Buying the pet does not count as a qualified expense, research animals and animals "utilized in conjunction with a trade or business" (uh, a mascot?) don't count, and you can't double-dip if you've claimed deductions for the animal in the last three years, but that's it.

It's a tax cut that helps individuals first and foremost. It encourages people to take good care of animals. I like these things. If you do too, write your representative and ask him or her to support this bill.

clonearmy@gmail.com — Wed, 14 Oct 2009 11:28:53 GMT

Two antennas got married.

The ceremony was nothing to write home about, but the reception was outstanding.

insert Imperial March here

clonearmy@gmail.com — Wed, 14 Oct 2009 07:29:11 GMT

Good hacking night last night. D came over so that we could hack on owen, my little NSLU2 box that's been on the shelf for, oh, a few years. After a few false starts (involving things like having to remember passwords I haven't used since 2005), we threw together a quick LAN off my laptop, got owen on that network, and successfully logged in. We then figured out that trying to configure a bridge between eth0 and ra0 was more trouble than it was worth, so no updating owen straight from the package server for now. I'll need to get the switch set up before I can actually drop owen on the main network, and I don't have the furniture for that right now, but owen clearly still works like a charm and now speaks DHCP, so overall I'll call that a win.

Our eventual goal is to set up pokylinux, as a "just to see if we can, since there's not a pokylinux build for this particular hardware yet" project, which will probably involve doing some compilation on the box itself. That's going to be slightly hilarious; I haven't done a multi-day toolchain build since, oh, 2001 or thereabouts. Good times.

Laterish today I'm going to pop round to the electronics store that also sells RC cars, planes and helicopters to see what my battery options are; I assume it's easier these days to supply 5V/500mA off something rechargeable than it was four years ago. (I need to be gainfully employed before I can actually buy one, as I expect sticker shock, but this is how budgets are made.)

I also dug up the little USB-to-Roomba-serial-interface circuit I was assembling some time back, and found the ostensibly Linux-compatible Bluetooth and 802.11g dongles that have been waiting ever so patiently. Yep, that's right -- after far too long on the shelf, the Evil Robot Vacuum Cleaner Army project is rolling once more.

PSA: use alternate email

clonearmy@gmail.com — Tue, 13 Oct 2009 11:55:37 GMT

The box that thesmartpolitenerd.com sits on appears to have fallen off the internet. (DNS believes it exists, but it's not answering pings.) It may be a little bit before it's fixed, as one of the lovely and talented folks who maintains it is currently in the hospital with an icky case of cellulitis, and I don't expect him or his equally lovely and talented wife to be pulling sysadmin duty when they have more pressing things to worry about.

For the meantime, please direct personal email to clonearmy at gmail, work email to the usual place work email goes. (If you should know it, you probably already do.)

Thanks, and sorry for the hassle.

ETA: Looks like it's back up and running as of approximately 6AM PST.