Getting the mp3 mess into control

I have some mp3 files in my collection. Some years ago, back in the times, when I was a Windows-User, I used „The Godfather„, to keep the chaos under control. This software, although not Open Source, is really good at what it does. And it does almost everything to organize mp3s. From (mass-)tagging to auto-renaming to auto-sorting your mp3s. But this wouldn’t be a blog entry by me if this became… a praise to a windows software so..

When I became a daily Linux User I searched for alternatives. With GUI or without a GUI, but I did not really find an application that suited my needs. As far as tagging and renaming was concerned it wasn’t that hard. There are really excellent command line tools (lltag, id3, etc.) and rumours have been heard that there are also GUI tools.
But what I still did not find is a simple, yet flexible, tool to sort a huge collection of mp3s into a flexible structure on the filesystem like „The Godfather“ was able to do since.. ehh.. a lot of years.

So the day before yesterday I finally decided to write one on my own and came up with an ~ 280 lines perl script (POD-documentation included) which does exactly what I want and is simple.
It does no tagging.
It does no renaming.
All it does is sorting mp3s into a given template-based directory hierarchy based on their ID3 tag.

At this point a warning is due. I’m sharing that script with you under the terms of the GPL. BUT it still needs testing and therefore you probably do not want to use it without its safety measures (e.g. dry-run or copy instead of move) to avoid data loss. And notice that although it has been written with portability in mind, it has only been tested on a Debian GNU/Linux system.

The script is hosted at github. Here (or raw to download it directly).

After I’ve talked to a co-worker about the script, he told me that arename would do what I want. So you probably don’t want to use my script, because arename is probably more tested and much more sophisticated. But on the other hand I had a quick look at the arename manpage and its so utterly feature-loaded, that it cannot avoid a certain complexicity. My tool is simple.
And there is another advantage. If you want arename to handle a certain amount of mp3s you have to use your shell magic to find the files and pipe it to arename. My script finds all mp3s recursively from where you let it start (default is $PWD so be careful) and will happily move it into a hierarchy under a directory you ask it to. For the simple job of sorting mp3s its probably easier to use.

(Oh and if its worth nothing, it might still be of use as a simple programming example, how one could solve this problem in Perl)

Facebook aggressively advertising dubious features

Yesterday some confusion arised on my side when I saw a new facebook advertising campaign in my facebook account (yes, I am a member of facebook, although I’m aware of the privacy concerns). Basically it was saying that I should try the friends finder and that some of my friends (showing and naming me three of them) would have used it already.

Some background:
The friends finder feature of facebook is a feature that asks for the password of your e-mail account. It will then crawl through your emails to find contacts that might already be on facebook but not connected to you (in a facebook sense).

My first feeling was: Oh my god. How can it be that friends (and family) of mine are so naive? Especially since there were people included which I consider to be quiet clever. But honestly: Who would be so naive to give an unknown company direct unsupervised (you can’t tell what they really do) access to your mail account? Would you give it to your friend? Your husband? Your father? I guess the answer will be „No“ in the most cases and these people are most likely people you trust. Well, I know, you could state similar things for Googlemail who crawl your mails to show you personalized advertising. And in fact you are right. But if one decides to use gmail for your email hosting you have to trust them anyway. Like you have to trust anybody else you retain to host your mails (who could do the same but just don’t tell you). But in this case its a third party, Facebook.

But if you now think that this becomes a rant against my friends: You are wrong. Over the day I found out that it basically shows up all my friends in a rotation. Every time I open the start page it randomly picks three people from my friend list and shows them to me, telling the same lie to me all over again.

So what do we have here? Facebook tries to advertise the most dubious feature they have in the most aggressive way one could imagine. By pretending wrong facts. Wouldn’t that even be an element of crime in Germany („Irreführung“ §5 UWG or maybe also §4 UWG, „unsachliche Beeinflussung“)?

Facebook, you can do better.

Update: Stefano raised a good point. I didn’t actually make clear that it has been verified that those people actually did not use the „feature“:

1. I asked some of them. They said, they didn’t use it and were in fact surprised that I asked.
2. Others told me they saw that ad stating that I used the feature. I definitely did not use this „feature“.
3. Probably weak: IMHO its highly unlikely that all of my friends used that feature and at the point I’ve written this it had already shown my whole friend list.

Ubuntu considering critical bugs an „invalid“ bug?

I just discovered that bug report over at Ubuntu.
Short summary:
They have a script in upstart which is not meant to be run manually and if you do it will erase your whole file system. Additionally it seems that the fact that you shall not run that script is not communicated anywhere.

That alone isn’t the most spectacular about it. Bugs happen. Whats spectacular about it is how a Canonical employee and member of the TechBoard (for people who don’t know it: The people who decide about the technical direction Ubuntu takes) handles that bug. One quote of him to reflect it all:

Sorry, the only response here is „Don’t Do That Then“

So what we have here is a classical case of bad programming. The problem in question is that the script expects a certain environment variable to be set. Fair enough. However it does not check if its set at all and instead of failing or using a sensible default it simply sticks to undefined behaviour. What we have here is a classical programming mistake every beginner tends to do. People who start programming often forget (or don’t know) that every external value we rely on must be considered untrustworthy. Therefore a good practice is to check those values.

In this case someone decided that this is useless because they suffer from the wrong assumption that nobody ever calls it manually and the other wrong assumption that caller of the scriptwill always set the environment variable correctly. This is a double-fail.

Now the developer in question does not accept that (someone else indicated why the behaviour of the script is dangerous), he simply says that the bug is invalid. Thats really a pity.

Debian translations – EPIC LOL

As a german I’m used to strange translations in computer context.
I saw it back when I was using Microsoft products and I regulary stumble upon it on Debian systems. But whats actually kind of funny:Debian is outstanding in that regard.
An example:
Debian has that „wonderful“ package manpages-de which provides a german manpage for ps.
It contains a formulation that is so inaccurate and not really funny:

„–cumulative Daten von toten Kindern einbeziehen (als Summe zusammen mit den Eltern)“

For the English only speakers: That can be roughly translated to „Collect data from dead children
(summed with their parents)“. For me this somehow sounds like we are a butcher OS and so I reported #495441 but nobody cared about it yet.

Today I had another WTF on german translations because when I wanted to upgrade my system I read the following sentence:

„Sind Sie sich sicher, dass Sie die oben genannten Pakete installieren bzw. aufrüsten wollen?“

Cold war, anyone?

Well its a classical case of using a word-by-word translation instead of a meaning-orientied translation. Its a fact that ‚upgrade‘ can be translated to ‚aufrüsten‘ (as done above) but in that case its just not appropriate. As a matter of fact most german people I’m aware of would actually confuse the meaning with a meaning such as in a military context (therefore the „Cold war, anyone?“ text above). And just btw. if we would rely on computing power to translate it back into English we would get:

Are you sure itself that you want to install and/or rig the packages specified above?

So it seems that Babelfish has a similar pereception.

Things that make you a good programmer

If you ever wondered if you are a good programmer (not), you might think about the following points:

1. Repeat yourself. How else would you keep yourself busy, if your customer has new requirements?

2. Re-Using code is for people who take the other side of the street if a big dog walks along. No risk, no fun. How else would you find out that the common idiom you use is really the way the job has to be done?

3. If you have a coding convention (e.g. how code has to be indented): Just ignore it. Its a good thing to have editors go crazy, when trying to automatically detect the indenting of a source file. By always confusing the editor you keep up the fun of the people, who try to change your code. It would be too boring for them, to simply edit the file, without the quiz which quoting applies to your code. Extra points for those who additionaly (to mixing tabs, spaces, 4 and 8 space, expandtab and no expandtab) write a vim modeline into their file that – by guarantee – does not match the indenting of the file.

4. If you can complicate things: Do it. Numeric indices in arrays can be exchanged by arbitrary strings, this makes your code more interesting. Especially if you have to move elements in that array. And complicated codes makes people, who don’t know it, think that you are a good programmer. One step nearer to your goal, isn’t it?

5. When working with different classes invent a system that auto-loads the classes you need. Don’t document it, that would be a risk for your job. Its not neccessary anyway, because good programmers like the riddle and finding out what gets called, where and why, is a simple but entertaining riddle. After all documenting is a bad idea as well. Especially if you make your system open source, because with a good documentation, it might be to easy for competitors to use your code to make money.

6. If you find ways to do extra function calls: Do it. It gives you the chance to refactor your code, if the customer notices that it is too slow. Great opportunity, hu?

(But, seriously: Don’t hear on me. Its just a cynical way to express my feelings.)

Building a 15W Debian GNU/Linux system

When the Intel Atom was revealed to the public I didn’t came around to say: „Wow!“, because that piece of hardware promises to be a generic-x86 1.6 GHZ CPU with a total power consumption of 2 Watt, which is amazing considering that x86 hardware generally wasn’t an option if you wanted to build a low-power system. But then the first chipsets were presented to the public and the Atom became a farce, because you don’t want to have a chipset that eats over 25W for a CPU which consumes 2W. That was basically laughable.

Recently I managed to find out that there is a new chipset out there, the Intel i945GSE, which runs at about 11W TDP, including the soldered-on-board N270 atom cpu. And I convinced myself that this could get my new homeserver. So together with a 2.5″ drive I could get a system which runs with about 15W maximum power consumption, which is amazing, given that the Arcor Easybox my provider gave to me seems to have similar maximum power consumptions. And it isn’t able to provide me with the great flexibility, the new Atom system is.

So I bought the following components:

  • Intel Essential Series D945GSEJT
  • A Mini-ITX M350 case, which is amazing, because its about the size of a Linksys router and should still provide a good thermal environment.
  • 2GB Kingston HyperX DDR2 533 MHZ S0 DIMM
  • a Western Digital Scorpio 320 GB hard-drive

It took a while to get those components together, especially because I previously decided for an Antec case which I ordered from K&M Elektronik, but as they didn’t keep their delivery promise I came to the M350. What a luck.

Running Debian on this machine is the easy part, you would think. This is true, for some exceptions. First: Lenny runs fine. I’ve installed the notebook hd in my desktop and then put it in the atom, when I got the first hardware and it worked right away. Except of a grub message, which is disturbing and which I didn’t manage to fix right now (grub says „Error: No such disk“ just to get the menu a seconds later anyway and boot the system flawless).

What didn‘ t work exactly reliable was the included network chip. Its quiet a shame to say that, but if you buy an Intel board, wouldn’t you expect that it would run Intel components? Unfortunately this is not true for the atom board. It has a Realtek RTL8111 network chip, which isn’t properly supported by the 2.6.26 kernel (that means the kernel think it is and loads a rtl8169 module, which isn’t able to properly detect a link).
The workaround for this is to use a 8168 module from Realtek and compile it for your kernel, but as I equipped this system with an Atheros 2424 PCIe chipset for playing WLAN AP, too, I had to upgrade to 2.6.31 anyway and there the chip is fully supported by 8169.

Making the system an access point has been surprisinly easy as well. The greatest pain was to find a Mini PCIe WLAN card, because after all this isn’t very common. However I found one based on an Atheros 2424 chipset and bought it. I additionaly bought an SMA-antenna connector that I could mount into the case (the M350 has a preparation hole for it) and an SMA antenna.
Setting this up, has been fairly easy. You need to know, that running master mode with newer mac-subsystem-drivers in Linux doesn’t allow setting master mode directly. Instead you need to use an application to manage everything, which is capable of running cards over netlink. Thats hostapd. The unfortune is, that the lenny version is too old and so I built myself a (hacky) backport of the sid version, which isn’t that hard anyway, because rebuilding against Lenny is enough. Additional you need a kernel 2.6.30 with compat-wireless extensions, or an 2.6.31, because previously the ath5k driver didn’t support the master mode. After that getting hostapd up is a matter of a 4 – 15 lines configuration file. For me its now running in 802.11g with WPA and a short rekeying interval with 14 lines of configuration.

After all I’m satisfied with the system. Without any fan the CPU constantly runs at 55°C, which is okay, given that it must operate within 0 and 90 °C according to the tech specs. The system and the disk are somewhat lower (47 and 39°C). The power of this system is more then enough. Its booting quick and working with it works without latencies, even when the system is doing something. What I haven’t yet tested is weither the power consumption actually fulfills the expactations. I will do so, once I got a wattmeter.

What an „Intel atom inside“ sticker could make of you

So I’ve got this cool Intel Atom-Board Intel Essential Series D945GSEJT, which is the first Atom-ITX-board that doesn’t feature a 25W chipset for a 2W CPU. Its pretty cool, but one thing made me laugh.
Today I saw that there came a „Intel atom inside“ sticker with the board. I thought: Well, nice, now I could – if I wanted – put this on my Mini-ITX-system. But then I saw whats been written next to this: „Use of the enclosed Intel Atom logo label is unauthorized and constitutes infringement of Intel’s exclusive trademark rights unless you have signed the Intel Atom logo trademark license„.

Isn’t it nice of Intel to supply me with a sticker which would make me a criminal if I’d use it?

Cool PHP-Code.

Did you know that in PHP you can write something like that:

$test = „foobar“;
$test = sTr_RePlace(„bar“, „baz“, $test);
$x = sPrinTf(„%s is strange.“, $test);

pRint $x . „n“;
eCho „foo“;

What makes me frighten is that this actually used, e.g. by this code snippet which exists (in a similar form) in an unnamed PHP-project:

echo sPrintF(_(„Bla bla bla: %s“), $bla))

And yes, they do use echo to output the result of sprintf.

Update: So i got this great comment. The commentator wants to point out that the senseless use of „echo sprintf“ is because of gettext. He says „That’s simply the way you use gettext.“ But this is simply not true. The difference between printf and sprintf is that the first one outputs the string, while the second one returns it. That means that in the above example printf could be used (instead of sprintf) without a useless echo call in front of it. The reason for using sprintf (and eventually the reason because you find it in a lot of applications using gettext) is that you can use it to fill a variable with the translated string or to use the string in-place. A common use-case for this is to handle a translated string to a template engine, for example.

PHP and the great „===“ operator

Lets suppose you’ve got an array with numeric indices:

[0] => ‚bla‘
[1] => ‚blub‘

Now you want to do something if the element ‚bla‘ is found in that array.
Well, you know that PHP has a function array_search, which returns the key(s) of the found values. Lets say, you write something like this:

if(array_search($array, ‚bla‘)) { do_something }

Would you expect that do_something would actually do something?
If yes: You are wrong.
If no: Great, you’ve understand some parts of PHP – insanitygoodness..

Actually, if ‚bla‘ wouldn’t have the index 0 it would work, because 1, 2, 3, 4, etc. is TRUE. But unfortunately PHP has some sort of implicit casting, which makes 0 behave like a FALSE, depending on the context. So following this, the if() works for all elements except 0.

You might be tempted to write

if(array_search… != FALSE)

But this wouldn’t help you, because 0 would still evaluate to FALSE, leading to if(FALSE != FALSE) which is (hopefully obviously) never true.

A PHP beginner (or even an intermediate, if he never stumbled across this case) might ask:
Whats the solution for this dilemma?

Luckily the PHP documentation is great. It tells you about this. And additionally PHP has got this great operator (===), which causes people to ask „WTF?“ when they hear about it for the first time. Additionaly to comparing the values to each other, they also check the type of the variable. This leads to the wanted result because 0 is an integer, while FALSE is Boolean. So the solution for our problem looks like this:

if (array_search($array, ‚bar‘) !== FALSE) {

Isn’t this great?