exercism.io : Creating code and discussing about it

September 6, 2014

Creating software is not only about hacking alone for hours and creating the “perfect” solution. It should always be about sharing inside into how creating elegant and maintainable code. But what a lot of software developer will experience is that discussing about code, trying to argue about how to code with fellow software developers at work is often impossible (for a number of reasons). So should you despair? If you are intererested in this kind of thing, there is a new (maybe just for me) website/community for something exactly like this: Creating code and talk about shortcomings or clever solutions. It’s called exercism.io. And it’s stated mission sounds like that:

  • There is immense value in comments and critiques of your code by your peers.
  • You grow and improve your ability to write code by reading others’ code and commenting on it.
  • As a better coder you help to improve the world of software development

This is the essence of Exercism.

Exercism is your place to engage in thoughtful conversations about code. Explore simplicity, idiomatic language features, and expressive readable code.

I’ve already created some javascript code and got some really good nitpicks, which is another way to say that I got good criticism in the form of suggestion and questions about how I created the code the way I did.

Why I like exercism.io that far: 
  • Easy to start
  • Tons of supported languages (Javascript, Python, c#, Go, Lua, …)
  • A nice command line interface program to let you automatically submit you code
  • A focus on TDD (test driven development)

Introduction to NoSQL by Martin Fowler

March 3, 2014

Set password for local oracle accounts and let them never expire again

March 3, 2014

If you are a getting warning messages like this one on your local developer oracle installation,

java.sql.SQLWarning: ORA-28002: the password will expire within 1 days

then there are two easy step to avoid the situation that you are not able to login with a given database user.

Step 1: Set the passsword policy to never expire passwords. Execute this SQL Query with your SYSTEM database user.

ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED;

Step 2: The expiring database user accounts are not affected by the above statements. You have to set a password for them to get rid of the warning and only then is the password never expiring again. You just have to start your “Run SQL Commandline” oracle console and first connect via the sysdba user (don’t be afraid, you don’t need a password for that one).

connect / as sysdba;

When you are connected successfully, just change the password for any database user

alter user SYSTEM identified by NEWPASSWORD;

(Disclainer: I’m no fan of oracle, but in my workplace I have to use it)

XPath evaluating in Chrome

October 23, 2013

IF you need to find HTML elements in a web page via XPath, it’s desirable to do this with an already existing web page in your browser. in Chrome/Chromium this is especially easy. If you open the web developer tools and switch to the console, you can type something like that

$x(“//*[@id='list']“) ;

And the browser will return you the found HTML element (or nothing if it does not exist).

Video: Web Development: You’re Doing It Wrong

May 20, 2013

Stefan Tilkov challenges many commonly-held assumptions about how to best develop web applications, emphasizing the strengths and ideal roles for HTML, CSS, JavaScript, HTTP and URIs.

The video about this topic can be found on infoq.com

Mythbusting Cloud Computing

May 13, 2013

An interesting video busting myths about cloud computing can be found on infoq.com

Khawaja Shams presents how NASA’s JPL uses cloud computing, and evaluates some of the existing cloud computing myths in the MythBusters style.

How to easily merge PDF files with linux

April 30, 2012

There is an easy way to merge two or more PDF files. You can use the free software called Pdftk. You can get it via the package system of your preferred linux distribution or the homepage of the project.

Here is an example for merging threepdf files

pdftk 1.pdf 2.pdf 3.pdf cat output 123.pdf

You can find more examples on the projects website.

A nice mono laser printer working with linux: Samsung ML1860

March 16, 2012

If you are looking for a  reasonable priced mono laser printer which works flawlessly under linux: I recommend the Samsung ML series. For example the Samsung ML1860.

For more information how to install the driver, just look here: http://ubuntuforums.org/showthread.php?t=341621

note to myself: compiling qt and installing as local user

February 27, 2012

I’ve decided to build kde4 trunk on my computer again. For this, one of the first steps was to get qt 4.8 running. As the debian repositories only contained qt 4.6, I had to build and instal qt for myself. I created a user named “kdedev” and a build and src directory in his home directory.

  • get the QT sources and place it under /home/kdedev/src :  git clone git://anongit.kde.org/qt
  • Change into the result qt directory and configure qt: .configure -no-phonon -prefix <where/I/install/Qt>
  • make
  • make install

voila, you have your working qt trunk installed in the home directory of a local user account…

Samsung Series 9 NP900X3A wireless Problems

February 12, 2012

After installing Ubuntu on my new Samsung Series 9 NP900X3A notebook, I was having massive problems with my wireless connection. The problem was, that the speed of the wireless connection was changing from full speed to transmitting nothing at all. After quite some googling and researching on the web, I found the solution.

gedit /etc/modprobe.d/iwlagn.conf
and add the line:
options iwlagn 11n_disable=1

The wireless controller is from intel… after all, I’m quite happy with the new notebook…


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