Archive for April, 2005

I give up

Thursday, April 14th, 2005

I’ve updated the examples yet again. Sigh.

Yet another syntax error

Wednesday, April 13th, 2005

Turns out that the WHILE loop in the factorial example program is missing parentheses:

WHILE i < 9 OR i = 9 DO

should be

WHILE (i < 9) OR (i = 9) DO

You’re only allowed to leave off the parentheses if there’s a single expression (as in the fibonacci program). What can I can say? Writing programs without a parser to check them isn’t easy.

Assignment 4

Wednesday, April 13th, 2005

I’ve posted Assignment 4. Since we discussed the assignment in class last Thursday, it shouldn’t come as any surprise.

Using Context-Free Grammars for Evil

Tuesday, April 12th, 2005

Oh dear. You realize that you can use CFGs to generate text, and not just to parse it, right?

Behold SCIgen - An Automatic CS Paper Generator

Disclaimer: if you try submitting one of these to a class and you get caught, don’t blame me.

Lab Exercises

Monday, April 11th, 2005

Click here for the Unit Testing Exercise and here for the project meeting agenda.

Stupid Spammer Tricks

Friday, April 8th, 2005

You’ve all seen those spam messages with subject lines like “Make $$$ Fast! libertarian expiation gonzo (xyzzy)”. The spammers include nonsense words in an attempt to fool Bayesian filters. It doesn’t work very well, but they still do it.

But here’s a new twist. The other day I got a spam e-mail whose subject line included the word “quadric.” Since we’d been talking about quadric surfaces in my graphics class just the other day, they almost got me to read their stupid advertisement.

I figured it was just a coincidence until yesterday I got one whose subject line contained “cryptanalysis.” I gather they’ve taken to scraping web pages: when they decide to spam, they first check to see if there’s a, then grab a statistically significant word from that page and use it in the subject line, hoping to fool you into opening it.

Clever, but not clever enough. Did I mention that both of the e-mails had already been automatically filed under “Spam?”

The DNS Poisoning Attacks

Friday, April 8th, 2005

As of this post, the latest update from SANS was here.

The attacks are serious enough that the Internet Storm Center has raised their Infocon level to “Yellow.” I know this because the icon in my system tray has turned yellow and started flashing.

Syntax Error

Friday, April 8th, 2005

Ok, so how long were you going to wait before telling me that one of the example programs had a syntax error?!?

Schedule Change

Monday, April 4th, 2005

Please note that I’ve rearranged the Course Outline slightly. We will spend the entire week on metrics, covering Chapters 15 and 22, returning to Chapter 21 next week.

Lab Session

Monday, April 4th, 2005

Click here for today’s Refactoring Exercise and here for the project meeting agenda.