However, one of the old servers had quite a few Perl modules installed via CPAN and some of our applications that we were migrating to the new servers depend heavily on these little suckers. Naturally, CPAN packages are handled from the CPAN utilities and not the system’s local package manager, which left me with a clean Perl install and none of the required modules once the new server finished installing all the Ubuntu packages…

After a quick Google-fu workout I stumbled across the ingenious “autobundle” feature for making bundled CPAN repository snapshots. This dumps all the installed packages and their version numbers in a snapshot file which is easily imported through CPAN on another host.

Here’s how!

Wow, that was fast! A quick look in our ~/.cpan directory shows us a newly created directory called “Bundle”, which is an installable CPAN package. In that directory we got our snapshot module, named by today’s date and the time we made the snapshot for easy archiving and separating different snapshots depending on when they were done.

To install it, just transfer the “Bundle” directory to your new server (along with the snapshot modules) and install it as you would install any other CPAN package or module:

This also makes a great feature for backing up your CPAN library state!

Now, if I only could get CPAN to automatically follow all dependencies without asking me for permission… Any ideas? ;-)

UPDATE: I found another thread from the hackers over at perlmonks.org with tips on how to get your autobundle ordered by dependency, so that CPAN doesn’t bug you about needed packages even though they are included later on in the list. Check it out!

This is useful in cases where you want the user to make a choice on their own instead of accepting a default value, or in cases where you can’t supply a default one. I wanted the validation to take place at client-side, before posting the form, so JavaScript is the only option.

I tried different approaches to this matter, but wound up with using the Prototype JavaScript framework which allowed me to construct an efficient little one-liner:

Replace the elements selector with your own. Just make sure it returns a collection of checkboxes or radio buttons. It will return boolean true if at least one of the elements is checked, otherwise false.

Since I try to use Subversion (SVN) for revision control of my code, I was pleased to know that there’s a mature extension to Eclipse called Subclipse which practically lets you create projects based on SVN repositories - as well as providing you with a complete Subversion client from inside of Eclipse. Branching! Tagging! Merging! You’ll never have to leave your IDE again.

When Googling for some actual cases on this sweet blend, I found an article posted by Sandy Smith that covers the initial setup of a PHP-powered project through SVN in Eclipse, as well as some other useful tips.

Check it out here: HOWTO: Use Eclipse PDT with Subversion in 13 Easy Steps.

The script I had in mind for this post is a nifty little critter (sveriges radio v1.0 by Stiffe) for browsing the different channels that are available on the public service radio network here in Sweden (SR, Sveriges Radio). It simply pops up a menu with the available channels and spawns a media player with the stream URL when a channel is selected. Neat and tidy, which is nice because the player available on their own site sucks (doesn’t play well with mplayer-mozilla or totem).

However, SR is known to change their streaming server URLs every now and then which naturally breaks the script. This ruined my Saturday morning, so I hacked together a small fix with the new URL.

I threw in a little bonus too: 10 extra channels that are broadcasted on the SR network, including SR C (highly experimental radio - this is the real deal, folks).

Download it here: sveriges_radio-v1.1.tar.gz

Feel free to comment on any bugs or make a feature requests!

X-Qmail-Scanner-1.25st: Process XXXX closed, parent process died

This message occurs every single time they tried to send mail to our customer.

It turns out they used a homebrew MUA which sent messages using Bare LFs as EOL instead of proper ones (according to document 822bis) - read DJB’s dwelling into this matter.

Our qmail system rejects the mail as supposed to, and informs the sender about the problem (along with the above link describing why it is one) - but it does not log the incident. This could make it really hard when troubleshooting why some connections drop from time to time.

However, Len Budney were way ahead of me and wrote this little tutorial on how to use DJB’s recordio tool (included in his ucspi-tcp package) for extracting the relevant 4xx and 5xx errors from the SMTP conversation. This makes sure we log it with everything else in our qmail-smtpd logs!

UPDATE: It seems that piping qmail-smtpd to recordio breaks SMTP TLS support. John M. Simpson writes the following on his excellent qmail information/patch collection site:

…It also means that, since the encrypted data stream is just as likely to contain a “0×00” byte as any other, and the C language treats the zero byte as an “end of string” marker, programs such like “recordio“, which involve themselves in the data stream between the client and qmail-smtpd, are likely to become confused.

Disable TLS by setting “DENY_TLS=1″ as an environment variable in your qmail-smtpd startup script, while troubleshooting with recordio. Don’t forget to remove both the recordio pipe and the environment variable when you’re done!

UPDATE #2: You can make qmail more forgiving by invoking fixcrio in your qmail-smtpd run script, before qmail-smtpd. This little tool is found in the ucspi-tcp package, and helps out by prepending a carriage return (CR) to every lone line feed (LF).

However, by going down this path you won’t tell the broken mailers that they’re actually broken…

Ben Simon writes on his blog on how he solved the issue nice and tidy by simply using a parent container for two child DIVs; the overlay and the map. Like this:

Using the following CSS markup:

Very nice, Ben!

My goal is to use this precious space to express my everyday thoughts, whether it’s code snippets I stumble upon during work hours, cool music thingies or just random stuff I have to get out of my head and through my fingers onto the keyboard.

Having a very wide spectrum of areas which I visit in my everyday work as a programmer and systems developer/administrator, I often stumble upon problems that needs to be solved. Just as often these problems has tons of cool solutions which fellow geeks has already worked out and published on the net, but I’m very (VERY) lazy and tend to forget this stuff as soon as I’m done with the project I worked on. Therefore, I want to use this blog as a way to save the cool stuff and maybe help spreading the word on my way through the space-time continuum.

Thanks for now.

Let’s see when my next update arrives…