Something that has bothered me forever is that applications that use GNU aspell for spell checking kept marking my name as a misspelling (I'm looking at you, KMail). Most front-end applications don't provide a way for you to add your own custom words.

Apparently, creating your own personal dictionary is ridiculous easy with aspell.

If your language is English, create a file in your home directory called ".aspell.en.pws":

The first line is a required header. Every subsequent line is a word you want to add to your dictionary. I can't believe I've let this sit for so long. Because it's a nice text file, syncing this file between machines to take your dictionary with you is trivially easy.

Drupal-powered websites can be put into an "offline mode." This is much better than most alternatives (such as taking the web server offline), especially for search engines, as the message and HTTP status codes given to users and robots alike will tell them to patiently come back later.

I've found that putting the site into offline mode makes database backups go much faster on heavily trafficked sites (which is obvious). However, for a particular site I was working with, this needed to be done in an automated manner, and on a dedicated database server that did not have access to the Drupal installation.

Most people take their Drupal sites offline through Drupal's web-based administration interface. They can also be put offline through the Drupal Shell. Neither were suitable for me: the former cannot be automated easily, and the latter requires access to the Drupal installation. Fortunately, Drupal sites can easily be taken offline by setting things in the database, which can easily be done via bash scripts and the command-line MySQL client.

Given your database user is my_db_user, password my_password, and database my_drupal_db, the backup script would look something similar to:

Update: The original version of this article had some problems on some setups with the variables table being cached. I added another SQL statement to make sure this cache is flushed so the site actually reflects its configuration.

Update: This method really doesn't work that well, and the more I think about it, there isn't a way to get around writing something that interacts with Drupal. I'm working on a script that will be more fool-proof.

Python provides a neat way for functions to return multiple arguments via "tuple unpacking". For example:

The same can be done in PHP relatively easily via the list construct:

SpamAssassin is one of the most-used spam filtering systems in use today. Unfortunately, because there are so many different ways SpamAssassin can be used, SpamAssassin remains subject to many performance problems. Fortunately, there are several speed-ups and optimizations that can be applied to most SpamAssassin installations to speed up its rule processing, especially on Debian and Ubuntu GNU/Linux-based systems. These instructions can be adopted to other operating systems as well.

This article does not discuss configuring your mail filtering system (i.e. procmail, maildrop). This depends completely on your setup, and more than likely there are plenty of other articles that describe the best way to setup what you want.

This past Ubucon's key signing party was my first key signing party. One thing I noticed--signing keys after a key signing party is a boring repetitive task. Summarized from the Ubuntu wiki entry on typical key signing post-party protocol:

1. Retrieve all public keys of key signing party participants, using gpg –-recv-key
2. Compare the hardcopy fingerprint from the keysigning party to the fingerprint of the retrieved public keys, using gpg –-fingerprint
3. Sign the key, using gpg –-sign Send the signed key back, either by
   • E-mail: export the key, then e-mail it to the key owner, using gpg –-export -a | mail -s “Your signed key” user@example.com
   • Key server: send the key to a public keyserver, using gpg –send-keys

This is incredibly monotonous—and people have to wonder why Web of Trust-based encryption is not more popular?

The Debian signing-party package provides the utility caff to automate some of this. It's not very friendly to “desktop” users, however:

• it's a CLI application
• it requires a local MTA (/usr/sbin/sendmail in particular), or an “open” SMTP server, with no support for authenticated SMTP or SMTP/SSL
• the configuration file syntax is Perl and confusing; there are also few examples on the Internet

You could add authenticated SMTP or SMTP/SSL support to the script, but having to know how to hack Perl definitely disqualifies caffe from being a desktop-friendly application.

So, I hacked together my own key signing party script in Python that would send signed keys back to people via KMail. To use it, create a text file listing all key IDs you wish to sign, one per line. Pipe the contents of this list into the script:

The script will download each key, ask you to verify the fingerprint, and then sign it. It then will open a KMail composer window, pre-filled with the key owner's e-mail address, a friendly template message (customizable in the script), and attached key. Review each e-mail to make sure it is kosher, and click send. Other than continuing to be a CLI program, I think this is much friendlier--the only manual work done is the creation of list of keys to sign, comparing fingerprints (this could be automated, but it seems in the spirit of the Web of Trust-based systems not to), and clicking send in a familiar desktop e-mail client.

Now for some notes...

It uses the DCOP automation features of KDE's Kmail to send messages. You could similarly use Evolution and D-Bus, but I don't use Evolution so I can't contribute that bit of functionality. Mozilla's Thunderbird unfortunately does not yet support any kind of automation features (as far as I know, anyway), so you're completely out of luck if you use it.

DCOP with Python is a complete, utter, pain. The easy way to drag-and-drop boiler-plate code with kdcop did not work, as it appears the APIs have changed. A problem with KDE/Python dcopext's module and multiple identically-named-functions sealed the deal for me and I gave up trying to use DCOP with Python, and instead settled for a hack of using the shell instead. I'm looking forward the one Linux desktop IPC protocol to rule them all, D-Bus, to debut in KDE4.

My script does not provide all the functionality of caffe. It, for example, does not encrypt the messages and their keys back to their owners. There doesn't appear to be an easy way to do this with KMail and DCOP, so it's a feature that will have to wait.

So, you've gotten your shiny new EVDO datacard working under Linux (if not, see High-speed cellular wireless modems (e.g. EVDO, HSPDA) in Ubuntu GNU/Linux 6.10) and you want to now setup the actual Internet connection?

In this article I document how I setup Sprint's Mobile Broadband service with ppp in Ubuntu GNU/Linux 6.10.

Note: If you are running Ubuntu 7.04 or greater, this article is no longer relevant. Your EVDO modem should be detected and run at a higher speed automatically.

I've been raving about cellular wireless modems/data cards for a while now. While they've been available for a long while, they've finally become practical with networks such as EVDO and HSPDA that offer broadband-like speeds. I personally own a Novatel Merlin S720 that I use with Sprint's Mobile Broadband service.

Most of these datacards are easy to get running in Linux--I actually setup mine in Linux faster than I did in Microsoft Windows. However, due to some shortcomings in the kernel used by Ubuntu GNU/Linux 6.10, you cannot take advantage of the speeds that these modern wireless networks offer.

This article talks about some of the problems of the often-used usbserial driver, and how to use the better-performing airprime driver instead.