jq - a JSON commandline tool (freifunk) - part I

Abusing the freifunk api to get more data

3 minute read

Everybody is interested in collecting data and build proper graphs out of it. In most cases the technical solution doesn’t matter until it shows graphs. Graph pr0n - basically. I am running a freifunk node to support the idea of an open WLAN network that is useful to everyone. If you need a network connection for whatever reason - freifunk is one solution if you are in desperate need of a network connection that is free and reliable.

German Umlaute with Perl Text::CSV

Why are my umlauts missing?

2 minute read

The following code is simple, easy to understand but it took me a while to figure that out. It was late at night, a production quick hack was waiting and some more things that happened at that time. I was using Text::CSV to write a well formed csv file with some formatting options. In short - I had the following (sample) data: my @data = ( { a => ‘Eklige Heisswasseraufbruehsuppe’, b => ‘Fiat Punto’ }, { a => ‘Drogenhölle Kleintierzüchterverein’, b => ‘Lada Niva’ }, { a => ‘Konsumrausch’, b => ‘Audi A4 Cabrio’ } ); Interestingly enough - the following script will persist that data into a csv file.

Fixing my rrd knowledge

Creating and working with rrd databases

4 minute read

I am using rrd databases for a quite a while now. Now and then I need to create a new database and I am constantly failing with this task. There are quite a number of reasons why - mostly I lost my references, my cheat sheets or I am too lazy to do the math. So here is -for me- a way how to create a rrd database without hurting yourself too much.