Parsing script or function options and non-option arguments is easy in Bash with getopts
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To list the sizes of Hive tables in Hadoop in GBs:

sudo -u hdfs hadoop fs -du /user/hive/warehouse/ | awk '/^[0-9]+/ { print int($1/(1024**3)) " [GB]\t" $2 }'

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I spent one afternoon adding a much needed feature to our application. Now I have been waiting for several days for various people to review and approve it. And I have just realized how tiring it is and how much energy it takes from me.

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With year 2012 over it is perhaps time to look back and see what interesting has happend, what I have done, written, learned, what articles I have enjoyed most etc.

This has been my second year in Norway and I am still very much enjoying it, there is a very active developer community organizing great conferences such as JavaZone (followed by an amazing trip to the nature a.k.a. SurvivalZone) and Smidig (Agile) where I have also presented, Scala-focused flatMap, many meetups etc.

Events & side jobs

Thanks to my company I had the opportunity to do some real consulting work, namely helping with a technical audit of an R&D department and co-organizing a TDD and refactoring workshop for the customer, and I have learned a lot from both of these.

The most exciting event was a week long educational stay with Ken Beck that has resulted in the most popular blog post ever of my company and myself, Programming Like Kent Beck. Another exciting event was the workshop BDD - Specification by Example by Gojko Adzic, simply the best workshop/course I have ever attended, with plenty of valuable content about how to build the right software. I also very much enjoyed preparing and presenting an introductory workshop into Clojure with my friends and collegues Lars and Ivar.


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The WordPress.com stats helper monkeys prepared a 2012 annual report for this blog.

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Recommended Readings

Software development
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What is actually good, clean code? Why does it matter?

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Recommended Readings

• James Roper: Scaling Scala vs Java (recommended by M. Odersky) - writing scalable apps in Scala is much easier then Java because idiomatic Scala uses immutable structures and lends itself naturally to asynchronous processing while doing these things in Java is possible but very unnatural and laborious. "It [Scala] is biased towards scaling, it encourages practices that help you scale."
• Exception Handling Antipatterns (2006, still valuable) - Log and Throw, Throwing Exception (instead of a suitable subclass), Throwing the Kitchen Sink (declaring many exceptions in method signature), Catching Exception (instead of a particular subclass), Destructive Wrapping (not including the exception as cause), Log and Return Null, Catch and Ignore (swallowing the exception), Throw from Within Finally, Multi-Line Log Messages (via repeated log calls instead of \n), Ignoring InterruptedException (instead of breaking the loop etc.), Relying on getCause().
• The GitHub way: Your team should work like an open source project - a provocative article about the development process in GitHub that strongly prefers asynchronous and on-line communication over face-to-face meetings and communication, which, according to the author, leads to increased productivity. That is quite the opposite of what is usually practiced. I can think of situation where direct interaction is invaluable but, on the other hand, I could certainly live with less meetings. (Comments on Hacker News)

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Recommended Readings

• David Veksler: Some lesser-known truths about programming - things newcomers into the field of IT don't know and don't expect, true and an interesting read. Not backed by good data but anyway. F.ex.: "[..] a programmer spends about 10-20% of his time writing code [..] much of the other 90% thinking, researching, and experimenting". "A good programmer is ten times more productive than an average programmer. A great programmer is 20-100 times more productive than the average [..]" "Bad programmers write code which lacks conceptual integrity, non-redundancy, hierarchy, and patterns, and so is very difficult to refactor." "Continuous change leads to software rot, which erodes the conceptual integrity of the original design." "A 2004 study found that most software projects (51%) will fail in a critical aspect, and 15% will fail totally."
• Brett L. Schuchert: Modern Mocking Tools and Black Magic - An example of power corrupting - interesting for two reasons: a good analysis of a poorly written piece of code and discussion of the code injection black magic (JMockIt) vs. actually breaking dependencies to enable tests.  The author presents a typical example of low-quality method (mixing multiple concerns, mixing different levels of abstractions, untestable due to a hardcoded use of an external call) and discusses ways to improve it and to make it testable. Recommended to read.
• It’s Not About the Unit Tests - Learning from iOS Developers: iOS developers don't do much testing yet they manage to produce high quality. How is that possible? The key isn't testing itself, but caring for the code. (Of course, iOS is little special: small apps, no legacy, a powerful platform that does lot for the apps, very visual apps.) "It’s not about the practices. It’s about the spirit and intent behind them, and how they are applied." (M. Fowler had a similar observation about a team that used mock-based testing exclusively and thus lacked integration tests yet all worked. [I've lost the link to the post and would be grateful for it])
• Java Code Quality Tools – Overview - brief descriptions of 44 quality-related tools including some interesting tools and Eclipse plugins I didn't know or knew but forgot. F.ex. analysis of dependencies with JBoss Tattletale or JarAnalyzer, Clirr to check libraries for source and binary backwards compatibility, JDiff generates JavaDoc-based report of removed/added/changed in an API. Spoon - read and check or transform Java code. Java PathFinder (NASA) - special JVM capable of checking all execution path to discover concurrency defects etc.

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Kent Beck in his recent post Functional TDD: A Clash of Cultures summarizes well the key principles and benefits that underlie test-driven development. I think it is really worthwhile becoming aware of and thinking over these foundation stones of TDD (and testing in general). Knowing them enables you to apply TDD in the most effective way with respect to a particular context to gain the maximum of these benefits. People that do not really understand the value of their tests and TDD tend to write hard to maintain tests of limited (and occasionally even negative) value. Are you one of them?


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To import a Leiningen
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Few troubleshooting tips for Puppet.

Where to Find the Cached Catalog On Client

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Screen (
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(By kristobalite) Clojure: Clean Structured Focused

(By agiamba) Scala: Adorned Overflowing Magnificent

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To load all fields from a tab-separated text file in Cascalog
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