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Author: halfgaar

http://www.halfgaar.net/

Halfgaar is Wiebe. Wiebe is a contributing author on this weblog. He also has a lot of stuff (such as long, in-depth articles) on his personal website.

Wiebe works at YTEC, where he is a senior developer of customer-specific tailor-made software (“klantspecifieke maatwerk software“) for clients in a few select markets: wholesale, printing and healthcare.

Silent change in URLs of Ruby on Rails svn repository

I don't know why, but everything associated with Ruby on Rails seems to change all the time, without notice, or (in the case of URLs) without redirect. Read More »

Creating a custom device node for specific hardware with udev

Sometimes you want specific hardware to get a specific device name in /dev. For example, I want my backup hard disk to have the same device name. I can't automate anything if sometimes the device is sdc and other times it's sdd. Read More »

Clonezilla as disk imager

I was always using partimage to make backups of the hard disks of workstations. When trying to restore one the other day, it just started giving CRC errors. After recreating the image and running a simulated restore, it gave CRC errors again. So, apparently, it's not incidental. It must be due to the experimental NTFS support. So, I set out to find a new tool. And that's how I found Clonezilla, which gives me a very good first impression. Read More »

Ultra Cheap dual Eizo monitor setup

As people who know me know, I passionately hate TFT screens, for reasons not relevant right now. It is unfortunate that marketing has caused the superior type of monitor, the CRT, to disappear. Read More »

Finding and deleting duplicate files

I needed to remove all duplicates In a collection of hundreds of thousands of files. I first came across this, which generates a script with commented out rm statements, but I quickly found another tool, fdupes, which made life a lot easier for me; I didn't want manual control. I just wanted to have all the duplicates deleted, except one of them. Read More »

Decoding djvu files on the command line

So, you have djvu files on a remote machine that you have SSH access to, and the local machine you're working on doesn't have djvu tools. What do you do? Simple, use ddjvu to decode the djvu files to images. Read More »

PostgreSQL back-end for Ruby on Rails confusion

I just need to add a quick summary of what postgres back-end tool our Ruby on Rails application uses, and how we've configured it, because it's quite confusing... Read More »

Disabling SSH shell access for SVN users on a Linux/Unix system

A common problem is that Linux/Unix system administrators want to grant users access to SVN repositories, but prevent them from logging in on the shell. This can be accomplished quite easily. Read More »

Configuring a Debian satellite Exim server

A very common way to configure Exim on a Debian machine, is to make it a 'satellite'; a server which uses another SMTP server for sending and does not do local delivery, the latter being the difference with a 'smarthost'. It can be used by other computers in the network to send mail, but also by the machine itself, to send system notifications and such (one of my favorite apps, arpwatch, for example). Read More »

Crane camera shots with just a tripod

When shooting footage with a motion camera, one of the most important things to achieve to avoid it looking like a home-barbecue video, is stable motion, normally achieved with a crane. A simple way to achieve this, is by retracting one leg of your tripod, and then tilt it forwards and backwards. This video gives a good demonstration. The difference between the tripod shots, and the hand-held shots (the shots made to demonstrate the technique) is astounding. Read More »