Author: Felix Leipold

  • CATting multiple files

    Quite often I want to pipe the content of multiple files into a command line utility. An example would be to count the lines of sql in my project. This is another case, where xargs comes in handy: find . -name “*.sql” | xargs cat | wc -l

  • Visualising log files with gnuplot

    I recently had the pleasure of supporting a new system throughout its first month of production. This was a good opportunity to refresh my command line skills. As it happened I spent a lot of time looking at log files trying to figure out what happened to the productions system. I figured, that a graphical…

  • On Immutability

    I quite like to use immutable value objects. They are really useful. However there are limits to this. Especially when it comes to objects with rich internal structures. Here you end up with a multi-line nested constructor call to create your object. I don’t think this is terribly readable. Also I see that people make…

  • Using the clipboard effectively – “Held der Kommandozeile”

    Every now and then even the über-geek can’t avoid the use of non-command-line-tools. Currently I am doing a bit of production support work, so tail, grep, and awk are my friends. However people expect emails, excel spreadsheets, and similar stuff. So what to do? Well use the best of both worlds pipe your output into…

  • Books to Go

    Ab sofort ist der podcast zur neuen hervorragenden “BOOKS TO GO”-Taschenbuchreihe des dtv verfügbar.

  • Seaside

    Last Thursday I had the honour of giving a talk on the seaside web framework. It is implemented in smalltalk and it provides a lot of interesting ideas: Using builders rather than templates to spit out html. A component model for composing interfaces as well as for expressing page flow. Encaspulating Ajax goodness Excellent debugging…

  • No Snowday for me

    As indicated earlier I didn’t take a “snowday” off work. Here is a picture of my bike down in aldgate where I worked that day:

  • JUnit-Shortcoming II: Fail on first failed Assertion

    In an earlier post I did describe a possibly better way of handling fixture tear down in JUnit. In this post I look at the way assertions work. JUnit is actually widely used as a driver for all kinds of tests, not only unit tests. I think this is perfectly reasonable as it leverages all…

  • Return on Investment

    The other day I bought mudguards and put them on my bicycle. I did pay off very well today.

  • Geld sparen und die Welt verbessern

    Im Grunde meines Herzens finde ich ja die folkloristischen Umtriebe der katholischen Kirche ganz lustig. Wenn das ganze aber in Richtung strafrechtliche Relevanz geht, hört der Spaß wohl doch auf. Ein kurzer Besuch beim Bund der Steuerzahler brachte folgende Erkenntnis: Wer in Hessen wohnt und 30.000,- EUR im Jahr verdient, zahlt im Jahr gut 400…