How to make screenshots and screencasts easily in Mac OS X?

In Mac OS X you can take a screenshot of the complete screen by pressing Command-Shift-3 and a selection of the screen by pressing Command-Shift-4. This is usually sufficient enough, but if you try to use this key combination to capture a screenshot of a movie running in the Mac OS X DVD Player you will be surprised to find out that this doesn't work. The same is true for the built in Grab Application.

If you still want to do capture a picture from a DVD you could use the screen-capture shell utility in the Terminal application - as described in several webpages.

But if you would like something more convenient you could use an application such as Jing ( It allows you not only to take a picture even from a movie running in the DVD Player but also to make a short videos of the your screen and provides several options to edit, save and share this pictures and videos afterwards. There is a Free version available as well as a Pro version with more functi…

7z files with Mac OS X

I am a fan of the free open source format 7z (see for data compression and encryption. With keka ( there is a nice, simple GUI application available for Mac OS X.

Create a Video DVD in Ubuntu 9.10 - the Karmic Koala

Assuming you have created a video file that you want to burn to a video DVD in Ubuntu.

A nice and simple tool for this is DeVeDe - a program to create video DVDs and CDs (VCD, sVCD or CVD), suitables for home players, from any number of video files, in any of the formats supported by Mplayer.

After you have created the .iso dvd image with DeVeDe you can easily burn it to the DVD using Brasero.

Merge multiple PDF files into one PDF file

Recently I needed to combine two PDF documents that I created with the TurboScan App on my Iphone (file sizes 528.5 kByte and 421.9 kByte and was searching for free options I can use with Ubuntu Linux. I found the following options:

The web service
Usability: Easy; excellent for merging PDF filesFunctionality: no other functions availableFile size of the merged file: 950.1 kByteThe free online PDF editor PDF Hammer

Usability: almost as easy as mergepdfFunctionality: other functions availableFile size of the merged file: 949.8 kByteThe Linux command linepdftk toolkit:
Usability: follow examples on the webpage; easy if you are comfortable with the command lineFunctionality: other functions availableFile size of the merged file:  949.8 kByteThe open source PDF editor PDFedit and
Usability: intuitive usage f…

Update to Ubuntu 9.10 (code name "Karmic Koala")

Yesterday I updated to the new Ubuntu 9.10. The update was as usual very smoothly (I accepted the default values when ask something).

After restarting, the following error message appeared:
Starting Google Desktop manually via the application menu did work. Still, I had to reinstall Google Desktop  via Synaptic in order to avoid this error message during startup.

The next message I got was:

I clicked on "Run this action now", followed the instructions and the missing language components got installed.

I used the following language settings:

Afterwards I enabled the third party repositories again (in "Software Sources"):

deb stable non-freedeb karmic maindeb-src karmic/deb karmic free non-freedeb-src karmic free non-freedeb karmic/
After relo…

How do I erase a computer hard disk securely with linux?

After I decided to scrap my more than 4 years old laptop, because it repeatedly failed after working some minutes after booting (when it fails, nothing worked usually any more than the mouse movement, sometimes even the screen display starts to blur; even booting from Live-CDs Ubuntu 8.10, etc. showed the same effect), I was looking for a secure way to delete all data.
I settled with:

shred -vfz -n 10 /dev/hda"

from, I had to use a very small Linux distribution (DSL), that was running completely in the RAM in order to be able to start the shred command (with other Live-CD's the laptop was failing already before I was able to start the command via a shell).

Update: This command was running nearly one week. At the end I tried to verify the success by removing the Live-CD and start to boot again. To my surprise, Ubuntu was still booting. I am still not sure, how to explain this. Anyway, I decided to remove the HD and destroy it mechanically. That should work and w…

Use Western Digital WDH1NC10000E My Book World Edition 1TB NAS network drive as backup destination for time machine on Mac OS X 10.5

As my 500GB Time Capsule has reached the limits (my Macbook and the iMac of my wife used it as backup destination for Time Machine), I decided to buy another backup drive and settled with the Western Digital WDH1NC10000E My Book World Edition 1TB NAS external drive. The main advantage (besides the price: I bought it for EUR 146,95 (incl. VAT and free transportation) for me was that I could easily connect it to a free Ethernet port of my Time Capsule - at least that was what I did expected. But after I connected the My Book to my network as discribed in the My Book manual, I had to discover that although it was available in the finder and I could manually copy files to it, it wasn't available in Time Machine as a back up destination.

Furtunately obvioulsly others experienced this problem before and after some googling I came to the solution described in the post "Time Machine backups on network shares in Leopard" from Florian Kruse. Following the steps described there I w…