This is mainly a test to see how adding this blog to my Buzz account works. Additionally I want to say how thrilled I am to finally buzz with people outside work

Overall the instructions on code.google.com are really good, so this is just a dump to remind me of the Ubuntu specific stuff I did on a pristine Ubuntu installation…


sudo apt-get install sun-java6-jdk
sudo apt-get install ruby-full rubygems


This installs only rubygems 1.3.1 but appengine needs 1.3.5.

ERROR: Error installing google-appengine:
bundler requires RubyGems version >= 1.3.5


sudo gem install rubygems-update
sudo /var/lib/gems/1.8/bin/update_rubygems
sudo gem install google-appengine


Et voilà! Ten minutes later I have a running hello world in the cloud

The usual problem: you want to kill a process.

$ ps aux | grep randomprocessname
psycho 20429 0.0 0.0 11824 1580 pts/7 S+ 12:00 0:00 /bin/bash ./randomprocessname
psycho 20528 0.0 0.0 4188 740 pts/17 R+ 12:00 0:00 grep randomprocessname
$ pkill -9 randomprocessname
WTF? Kill that sucker!
$ pkill -9 randomprocessname
No typo... Am I crazy?
$ pgrep randomprocessname
What's wrong?
$ pgrep randomprocessna
20429
$ pkill -9 randomprocessna

For some arcane reason pgrep/pkill matches only the first 15 characters.

Quite some time has passed since the last time I wrote something on this blog, mostly because I did little non-work related worth mentioning.

But last week I helped Damon to finally support JRuby on his Android Scripting Environment (ASE).

• Downloaded JRuby sources (jruby-1.2.0RC1) from http://www.jruby.org/download.
• Patched the build.xml to not include doc/index.html from dynalang.jar otherwise dx will complain about an HTML page in the ruby-complete.jar.
  
  

  $ diff -r jruby-1.2.0RC1 jruby-1.2.0RC1.patched/
  Only in jruby-1.2.0RC1.patched/: build
  diff -r jruby-1.2.0RC1/build.xml jruby-1.2.0RC1.patched/build.xml
  42c42
  <
  ---
  >
  238c238,240
  <         <zipfileset src="${build.lib.dir}/dynalang-0.3.jar"/>
  ---
  >         <zipfileset src="${build.lib.dir}/dynalang-0.3.jar">
  >           <exclude name="**/doc/index.html"/>
  >         </zipfileset>
  268c270,272
  <         <zipfileset src="${build.lib.dir}/dynalang-0.3.jar"/>
  ---
  >         <zipfileset src="${build.lib.dir}/dynalang-0.3.jar">
  >           <exclude name="**/doc/index.html"/>
  >         </zipfileset>
  387c391,393
  <         <zipfileset src="${build.lib.dir}/dynalang-0.3.jar"/>
  ---
  >         <zipfileset src="${build.lib.dir}/dynalang-0.3.jar">
  >           <exclude name="**/doc/index.html"/>
  >         </zipfileset>

• Downloaded the JSON sources from http://rubyforge.org/frs/?group_id=953 and put them in lib/ruby/1.8/json/
• Copied android.rb to lib/ruby/1.8/.
• Built jar-complete (ant jar-complete) and added jruby-complete.jar to eclipse project.
• Connected the bits and pieces in com.google.ase.interpreter.jruby

But beware! The new ASE apk is HUGE (4.6M) and JRuby is fairly slow. But it works

Seems like nowadays I only write blog posts in response to other blog articles… But I hope this is better than not writing at all. Ted Neward asks if code reviews do actually work because evidence suggests, that the scientific review process does not. Read the rest of this entry »

Sometimes you want to reset a database to its virgin state, without actually deleting and re-creating the whole database (perhaps because your user doesn’t have the right to create a database). There are a lot of links out there that give you a quick answer on how to drop all tables from a database in a single-line shell script. Some examples:

• http://www.thingy-ma-jig.co.uk/blog/10-10-2006/mysql-drop-all-tables
• http://www.cyberciti.biz/faq/how-do-i-empty-mysql-database/
• http://knaddison.com/technology/mysql-drop-all-tables-database-using-single-command-line-command

However this does not work if there are foreign key constraints between the tables (because the tables constraining others need to be deleted first). Here’s the advanced version that solves this problem:

#!/bin/bash
USERNAME=myUser
PASSWORD=myPassword
HOSTNAME=dbHost
DATABASE=mydb
while (true) ; do
    TABLES=`mysql -h $HOSTNAME -u $USERNAME -D $DATABASE --password=$PASSWORD 
                  --batch -e "show tables" | grep -v Tables_in`
    if [ -z $TABLES ] ; then break; fi
    for i in $TABLES ; do
        mysql -h $HOSTNAME -u $USERNAME -D $DATABASE --password=$PASSWORD  -e "drop table $i"
    done
done

I agree this is not nice because it’s a brute force approach – but hey, it works! And resetting a database is most probably not a performance-critical task anyway.

I am looking for an intern (more details) for later this year. I have a number of interesting ideas for projects, most of them involve Ruby (more specific JRuby), Android and Eclipse. Your skill set should include at least Java and if possible Ruby and/or Eclipse API.

I’m looking for a commitment of at least three months (I would prefer six) and you should be within one or two years of receiving degree. If this sounds interesting please apply here and add a note that you would like to work with Frank Spychalski in Munich.

Yesterday was Girl’s day and our office hosted a few girls from schools in and around Munich. Read the rest of this entry »

I found the DIY page for demotivators and had to create one for Ruby. Enjoy!

Second day has started. Today it starts with a few talks on testing…

George Malamidis — „Synthesized Testing“

Already 15min behind schedule, but so far interesting.

This has 4 lines of code. It is already a big ruby function.

Vassilis Rizopoulos — „rutema: One test tool to rule them all“

I’m thinking on how to write in a polite way “This talk was boring”. It was. And the tool uses XML Hey, this is a Ruby conference- you should use YAML or even better a cool Ruby DSL.

Tomasz Stachewicz — „Sharing the load“

Sounded interesting but there was a question after the talk which suggested that the guys reinvented the wheel and that BackgroundDrb is a better solution for what he has done.

Petr Krontorád — „Building Rails Playground – using Ruby’s dynamic nature“

Mumble, mumble, small text, cannot read the slides, mumble… Sorry I don’t have a clue what this talk is about.

Tim Becker — „Lessons Learned Writing Native Extensions“

Type-along tutorial on how to write C extension for Ruby. Very interesting, this could actually make me write C code again… He has started talking on cats and tigers and it seems like he wants to teach us how arrays work in C. Booooooooring. Finally he is done with this and is back on the interesting topics like conversion of data types. Overall a really interesting talk. By far the best one today so far. Tim’s post with code samples and links.

Matt Ford — „Aspect Oriented Programming in Ruby“

It’s his birthday. Happy birthday Matt! He talks about Aquarium a neat aspect oriented programming solution for Ruby. Very nice. I have to play around with this when I’m back home.

Dushan Wegner — „Philosophy & Programming“

This first lightning talk. “Imagine I’m holding a beer and put out this ideas”. “Programmers are better philosophers”. A very cool talk about the similarities of programming and practicing philosophy.

Marcin Raczkowski — „Distributed programming with ruby“

Hard to understand but interesting. Sadly it is impossible to read his code when he is showing examples in the editor.

sorry missed name and title Akira Tanaka – „IO.copy_stream“

Interesting talk about IO in Ruby. Great final “status” slide:

Accepted by Matz yesterday @La fabrica
Submitted today to Ruby 1.9

Wow!

Gregor … — „Context-oriented programming for Ruby“

Took a long time to get to the point. Which part of lightning talk did you not understand.

Florian Gilcher — „Patterns (yet another) pattern matching library“

Interesting talk. Can be found at patterns.rubyforge.org.

Raimonds Simanovskis — „Using Ruby with Oracle“

Good quick talk. I never had to work with Oracle so I never had the problems he was talking about.

Daniel Liszka — „One RubyStack to Rule them All“

Strong accent, to much text on the slides. But sounds like a neat idea… www.bitnami.org/stack/rubystack

Ry Dahl — „Ebb Web Server“

Yet another Ruby web server, obviously it’s faster than all the others because what would be the point otherwise. ebb.rubyforge.org

Wouter de Bie — „Capistrano, Webistrano“

The final lightning talk. I’m hungry off to find some food…

Dr Nic — Demo

So it wasn’t the last talk. They squeezed in a short demo on how to use his gem generator. Very cool! I have to use this to play around with native C extensions.

Final announcement

It seems like next year’s EURUKO will be in Madrid. Great! Never been there. See you next year! It’s not decided yet. Krakow and Warsaw are possible sites, too. Hm, I’m still for Madrid

Sumary

I think I should have slept in today like Todd and would not have missed a bit. Here are some pictures from EURUKO 2008 on Flickr and even one with me. EURUKO was great. A big “thank you!” to all the people who have organized it. I’m sure I will be back next year, no matter where.