Use PostgreSQL REPLACE() to replace dots with commas (dollar to euro)

If you have set up your database tables correctly you might be using double-precision floating numbers to store currency values. This works great because dollars use dots to represent decimals. The problem starts when it’s not actually dollars you are storing but euros, and maybe you need to copy query output to Excel or LibreOffice […]

Can we replace paper?

Paper always beats rock and scissors. Because one of the few inventions greater than writing itself, is writing on paper. Paper writings are absolute, self-contained and transferable units of knowledge, which after publishing become and stay available and accessible for hundreds of years or more. Don’t take my word for it, there is this great […]

Advent of Code

Currently the yearly Advent of Code contest created by Eric Wastl is being held at adventofcode.com. That means the site is sprouting two daily programming challenges, until Christmas, to see who can solve them fastest. But it is not just about being fast of course, Advent of Code is a great way to improve your programming […]

Save data from your broken Raspberry Pi SD card with GNU ddrescue

This week my Pi stopped working. After hooking up a monitor I saw kernel errors related to VFS. So the file system was obviously broken. Oops. The end conclusion is that the SD card is physically ‘broken’, but I still managed to salvage my data — which is more important than the card. Here’s how. […]

The Phoenix Project

When a co-worker handed me a copy of The Phoenix Project, the 8-bit art on the cover looked fun. But the tagline — ‘A Novel About IT, DevOps and Helping your Business Win’ — sounded a bit like the usual buzzword management lingo. But I was clearly wrong, I loved this book! It is unlike […]

Linux server principles

This is a list, in no particular order, of principles to adhere when running a secure Linux server. SSH – Never allow direct SSH root access (set PermitRootLogin No). SSH – Do not use SSH keys without a passphrase. SSH – If possible, do not run SSH on a public IP interface (preferably use a […]

GNU coreutils comm is amazing

Most people know sort and uniq (or even diff) and usually use a mix of these tools when comparing two files. However sometimes, there is a shorter solution than piping different commands together: comm is your answer! The comm(1) command is one of the most powerful but also underused text tools in the coreutils package. Comm’s […]

My Vim setup

The following lines are in my .vimrc file and make working with Vim all the better! I keep it pretty basic, so I don’t use the very popular fugitive.vim or NERDTree plugin. Put these lines in ~/.vimrc or /etc/vim/vimrc (depending on your distro, sometimes they are already there but need to be uncommented), and you’re […]

The Soul of a New Machine – Tracy Kidder

The Soul of a New Machine by Tracy Kidder is one of those books that always seems to pop up when ‘computer-people’ share book recommendations. Exhibit A, exhibit B, exhibit C and so on — you get the picture. Also the “Winner of the Pulitzer Price” notion on the cover seemed promising, and it was about computers, […]

Favorite 2017 purchases

Here’s a chronological list of some of the physical things/tools/gadgets I bought in 2017. Physical as in, I’m leaving out experiences, books and cryptocoins. Here we go. The Sony MDR-ZX110 headphones are decent aka good enough for my use, but more importantly also cheap enough so I don’t have to worry when I break them, […]

Django in 10 minutes

This post is for myself, two weeks ago. I needed something like this. Or, maybe it’s for you? You know a little bit of Python, kind of understand the MVC concept and have a clear understanding of RDBMS? Congratulations, you will have no trouble getting something up and running in Django in a couple of […]