## Archive for Mai, 2007

### Comfortable Wireless Networking with Linux

Dienstag, Mai 29th, 2007

Until a few minutes ago I was not really happy with the current configuration for (wireless) networking on my notebook. When I wanted to change to another (wireless) network (e.g. when I was not at home), I had to go to the network settings and change the network there. If I went to a new place, I had to use iwlist scanning to find out which networks were available and then manually enter the essid to the form. Connecting to the network was then rather slow, sometimes it did not work (always switched back to another network that was not available at the current place) and I had to reboot. Thanks to Clem who told me about the NetworkManager this is now over. Originally it is a gnome-tool but it works perfectly on my Ubuntu with XFCE.

I installed NetworkManager by the command sudo apt-get install network-manager, commented out (with #) all lines except those with lo in /etc/network/interfaces and rebooted. The first time I had to start the NetworkManager using nm-applet, since then a small applet has been in my xfce-panel. Similar to windows I can click on it to display available networks. By clicking on an entry, I can connect to the corresponding network (and enter the network key).

### Switching from Gaim to Pidgin

Montag, Mai 28th, 2007

It has now been for a while that Gaim has changed its name to Pidgin (no, it is not pigeon…) due to a lawsuit with AOL and published the version 2 of this instant messenger. Now they have released 2.0.1, so I decided to install this new version.
My Ubuntu did not automatically install the new version. Unfortunately I could not find a .deb-package for Pidgin, so I had to compile Pidgin myself. Before doing that I made a backup of my folder ~/.gaim containing my preferences.

First, I had to download the source and then unpack the .tar.bz2-file using the command tar -xjf pidgin-2.0.1.tar.bz2. After a cd pidgin-2.0.1, I executed the first of the classic three commands to compile a program: ./configure. Unfortunately I got the message You must have libxml2 >= 2.6.0 development headers installed to build. so that I had to install sudo apt-get install libxml2-dev before again executing ./configure. This time everything went well and I was told configure complete, now type ‚make‘. Obviously I followed this advise and typed make which busied my aging computer for a couple of minutes. To finalize the installation I had to type make install. After that, everything was ok.
I can now start Pidgin by typing pidgin in the terminal or by using the entry in the menu (Network -> Pidgin Instant Messenger).

Pidgin does not seem to have changed a lot compared to the beta version of Gaim 2 that I had installed before (however it has changed a lot compared to the older versions). The design and icons are different and more modern, but the functionalities are about the same. Unfortunately it does not support video or voice chats, but personally I prefer writing over talking, so this missing feature does not really disturb me. What I really appreciate is that Pidgin supports no less than 15 different protocols. As an example, I use it for my ICQ, MSN and GoogleTalk accounts.

### How to easily sort out bad pictures

Mittwoch, Mai 23rd, 2007

If you take many pictures from events or sport matches you certainly know the problem of separating the good pictures from the trash. Most image manipulation programs like are too heavy to use them for sorting the pictures. However, there exists a very light-weighted tool for Linux (and Solaris and FreeBSD): qiv, Quick Image Viewer. Although the download has only about 100KB (provided that gtk+/gdk and Imlib are installed), it offers an incredible number of functions.

Under Ubuntu the installation of qiv is very easy sudo apt-get install qiv. After the installation, qiv can be started using the command qiv  where path can be a file or a folder whose content should be displayed. In addition to this pure paths, operators like the * are also possible, for exampleqiv *.jpg opens all .jpg-files in the current folder.

When qiv is the current window and displays an image, many commands (use man qiv for an exhaustive list) can be used. Actually I use only a few of them. The most frequently used commands are:

• space bar: display next picture
• backspace: display previous picture
• Page Up: go five pictures forward
• Page Down: go five pictures backward
• d: delete the currently displayed image
• u: undelete the previously deleted image
• q: close qiv

When you delete an image it is actually not deleted but moved to a folder .qiv-trash (in the folder of the pictures), so it can be recovered later. At the end of the sorting, it is quite wise to delete this folder using rm -rf .qiv-trash to save some space.

Using qiv I have managed to considerably speed up the tedious task of sorting the images before editing and publishing the good ones.

### Zattoo for Linux

Freitag, Mai 18th, 2007

Finally Zattoo is available for Linux! Today I’ve got a newsletter from Zattoo telling me that Zattoo can now be downloaded for Linux. With Zattoo 43 TV-channels are available for free. You simply have to register (which means: indicate the email-address and choose a password), download and install the software (for Windows, Mac and Linux), start it, login and choose the channel. It is very easy to use and the quality is surprisingly high. There are more channels than we get with Cablecom and it is free. The software is available in English, Deutsch, Dansk et Français (la versione italiana e la versiun romontscha mauncan aunc…).

I immediately downloaded the .deb-package of Zattoo (rpm’s are also available) for Linux and installed it on my Ubuntu Edgy Eft. The installation was very easy, however it did not work on the first try: When executing the command sudo dpkg -i zattoo-2.2.8.5561-i386.deb the installation failed with the message Package libgtkglext1 is not installed. I therefore installed this missing package with sudo apt-get install libgtkglext1, then re-executed the command sudo dpkg -i zattoo-2.2.8.5561-i386.deb and after a few seconds everything was fine.
Using the terminal I could start Zattoo with the command zattoo_player & (it could also be started using the menu Multimedia and then Zattoo player, but personally I prefer the terminal), log in and choose the channel and enjoy the new TV. It works!

### Tables in LaTeX

Donnerstag, Mai 17th, 2007

Have you ever created any tables in LaTeX? In my opinion tables are definitely one (the only one) of the weak points of this wonderful typesetting system. With LaTeX most common tasks (write a „normal“ report, standard formatting etc) are extremely easy, but creating tables with seems to be an occasion to tear one’s hair. Really? No!
Indeed there is a wonderful trick (thanks to Jutta for this hint) to easily add wonderful tables to your document: simply create it as a spreadsheet in the spreadsheet program of your favourite office suite (I recommend OpenOffice). Do not format the table, this is pure waste of time as all formatting will be lost later.
After you are done, save the table as Text CSV (.csv). Instead of saving the file with the standard CSV options, modify these options as follows: set the field delimiter to & and remove the text delimiter. This creates a .csv-file, in our example it is
expenses&2006&2007 replacement of dishes&300$&14$ fines for speeding&3500$&0$ fines for dodging paying the fare in trains&0$&600$ bail to be released after drug tracking&400$&1400$ 
Open this .csv-file in a text editor and copy its content to your favourite LaTeX editor (e.g. Kile). Now you simply have to modify this code to change it into a correct LaTeX table: add \\ at the end of each line of the table, add a \hline where you want a horizontal line, escape special characters (e.g. in our example the $sign) with a backslash \ and add (i.e. copy it from another document) the surrounding code like \begin{tabular}: \begin{table} \begin{center} \begin{tabular}{|l|r|r|} \hline expenses&2006&2007\\ \hline replacement of dishes&300\$&14\$\\ \hline fines for speeding&3500\$&0\$\\ \hline fines for dodging paying the fare in trains&0\$&600\$\\ \hline bail to be released after drug tracking&400\$&1400\\$ \\ \hline \end{tabular} \label{tab:expenses} \caption{Personal Expenses in 2006 and 2007.} \end{center} \end{table}

Even though the above code still seems to be complicated (it isn’t as you will realise when taking a closer look at it), this trick really simplifies the task of creating a table in LaTeX. When using it, the creation of tables in LaTeX does not become the easiest part of LaTeX but it is no more tedious and the countless advantages of LaTeX over Word make editing a report fare more efficient with LaTeX despite the rather cumbersome creation of tables.

I will talk about the advantages of LaTeX in a later post, so just look back later (or better: subscribe to my RSS-Feed).