Dexpot

Josh VanderLinden

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I often find myself in need of more screen space when I'm using my computer. I have so many different things up on my screen at all times. Since Linux is my default operating system, I take advantage of the virtual desktop functionality that is built into most every popular window manager to make it seem like I have more screen space.

This is all fine and dandy, but it makes using Windows all the more frustrating to me. I've tried some utilities in the past that offered virtual desktop capabilities, but they always seemed weak and crashed a lot. For years I had given up on virtual desktops in Windows.

Today I decided to look into the current options for such functionality in Windows. In my searching, I came across Dexpot. I installed it, and it seems to be doing exactly what I want and more! It seems to be stable, and it only takes up 8,776K of my memory. That part could be better, but I'm not complaining :)

Anyway, I thought some of you might benefit from this utility as well.

Step-by-Step: Installing Django

Josh VanderLinden

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Being the Django and Python zealot that I am, I often find myself trying to convert those around me to this awesome development paradigm. Once I break them, these people often ask me a lot of questions about Django. Over the past few months I've noticed that one of the biggest sticking points for people who are new to Django is actually getting it up and running to begin with. In response, this is the first in a series of articles dedicated to getting Django up and running.

What is Django?

The Django Web site describes Django as "a high-level Python Web framework that encourages rapid development and clean, pragmatic design." Basically, Django is just about the most amazing thing for Web development. I have tinkered with several different Web technologies, but nothing seems to even come close to what Django can do for me.

What is Python?

Python is a programming language used in numerous aspects of computing these days. It has a very simple yet powerful syntax. It's an easy language for beginners to pick up, but it provides adequate levels of power for the more experienced developers out there. If you have never programmed anything before, or you have dabbled with something like BASIC, Python should be fairly straightforward. If you are a programming veteran, but have only worked with languages like C, C++, Java, etc, you might struggle a bit with the syntax of the language. It's not difficult to overcome the differences in a couple hours of hands-on development.

Let's get started.

Installing Python...

Having Python installed is critical--Django does not work without Python. I'm guessing that you're relatively familiar with the procedures for installing software packages on your particular operating system. However, I will share a few notes to point you in the proper direction if you're lost. If nothing else, just head over to the Python download page to download anything you need to install Python. I whole-heartedly recommend using the latest stable version of Python for Django, but you should be able to get by with as early a version as 2.3.

...On Windows

Simply grab the latest version of the Python installer. It is currently version 2.5.2. Once the installer has downloaded successfully, just run through the installation wizard like any other setup program.

...On Mac OS X

Recent Mac OS X computers come with Python pre-installed. To determine whether or not you actually have it, launch the Terminal (Applications > Utilities > Terminal) and type python -c "import sys; print sys.version". If Python is already installed, you will see the version you have installed. If you have a version that is less than 2.3, you should download the newest version. If you don't have Python installed, you will get a "command not found" error. If you're in this boat, just download the latest version of the Python Universal installer and install it.

...On Linux

Most Linux distributions also have Python pre-installed. Just like with Mac OS X, you can check to see by opening up a terminal/konsole session and running the command python -c "import sys; print sys.version". If you have Python installed, you will see its version. If you get an error message when running that command, or you have a version earlier than 2.3, you need to download and install the latest version of Python.

If you're running a Debian-based distribution (like Ubuntu, sidux, MEPIS, KNOPPIX, etc), you can probably use sudo apt-get install python to get Python. If you're running an RPM-based Distribution, you can probably use something like Yum or YaST to install Python.

A sure-fire way to install Python on any Linux system, however, is to install from source. If you need to do this, you simply:

  1. download the source for the latest version of Python
  2. extract it: tar jxf Python-2.5.2.tar.bz2
  3. go into the newly-extracted directory: cd python-2.5.2
  4. configure it: ./configure
  5. compile it: make
  6. install it: make install

(I've only installed Python from source one time, so I might be wrong)

Setting Up Your PYTHONPATH...

Generally speaking, if you didn't have Python installed before starting this tutorial, you will need to setup your PYTHONPATH environment variable. This is a variable that lets Python know where to find useful things (like Django).

...On Windows

  • Open up your System Properties (Win+Break or right click on "My Computer" on your desktop and select Properties)
  • Go to the "Advanced" tab
  • Click the "Environment Variables" button
  • If you have permission to change system variables, click the "New" button in the bottom pane. Otherwise, create the PYTHONPATH variable for your user account using the "New" button in the top (User variables for [username]) pane.
  • Set the variable name to PYTHONPATH
  • Set the variable value to C:\Python25\Lib\site-packages (replace C:\Python25\ with whatever it is on your system if needed)
  • Save it

You may also need to add the python executable to your PATH. If you can successfully run python from a command prompt window, you don't need to worry about it.

If you can't run python from a command prompt, follow the procedure above, but use the PATH variable instead of PYTHONPATH. PATH most likely already exists, so you just need to append/prepend the existing value with something like C:\Python25\ (again, this might need to change depending on where you installed Python)

...On Mac OS X

Your PYTHONPATH should already be setup for you.

...On Linux

Usually you just need to edit your ~/.bash_rc script to setup your PYTHONPATH environment variable. Go ahead and open that up in your preferred text editor and make sure there's something in it like:

export PYTHONPATH=/usr/lib/python2.5/site-packages:$PYTHONPATH

Save any changes necessary and run the following command:

source ~/.bash_rc

This will take care of updating your current session with any changes you made to your ~/.bash_rc.

Installing Django

Once you have Python and have verified that you have version 2.3 or later, you are ready to install Django. Currently, the latest stable release is 0.96.1, but this is grossly out-dated. Django 1.0 will be released on September 2nd 2008, so the "unstable" copy of Django is pretty close to what 1.0 will have to offer. There are some incredibly useful improvements in the unstable version that I don't think I could do without anymore, so that's what I'll talk about installing here.

First, you need to have a subversion client. On Windows, the most popular one is called TortoiseSVN. On Mac OS X, I have played with a few, but I think Versions is a pretty decent one. Linux also has several to choose from, but if you're using Linux, you're probably going to use the command line anyway (right?).

For brevity, I will just use the subversion commands necessary to accomplish this task (instead of discussing all GUI interfaces to subversion).

The exact location that Django should be installed differs from system to system, but here are some guidelines for typical setups:

  • Windows: C:\Python25\Lib\site-packages
  • Linux: /usr/lib/python2.5/site-packages
  • Mac OS X: /Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages

If you want a definite location, run the following command:

python -c "from distutils.sysconfig import get_python_lib; print get_python_lib()"

Once you know that location, go there in your command prompt or terminal session. Then execute this command svn co http://code.djangoproject.com/svn/django/trunk/django django. You will see loads of output, showing all of the files that you are downloading as you install Django.

As soon as that process completes, you should run python -c "import django" to make sure everything worked properly. If the command doesn't display an ImportError, you're good. Otherwise, you need to try again.

Getting Access to Django Scripts...

Once you can successfully import django, you might want to make sure you can run the django-admin.py script that comes with Django.

...On Windows

This process is very similar to what we did with the PYTHONPATH environment variable earlier.

  • Open your System Properties again
  • Go to the Advanced tab
  • Click the Environment Variables button
  • Find your PATH environment variable (either for your user or system-wide)
  • Make sure that the variable value contains something like C:\Python25\Lib\site-packages\django\bin
  • Save any changes
  • Open a fresh command prompt
  • Try to run django-admin.py. If you're successful, you're ready to get started with Django. Otherwise, you need to fix your path to django/bin or just call the django-admin.py script using an absolute path when needed.

...On Mac OS X

You can run a command similar to this:

sudo ln -s /Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/bin/django-admin.py /usr/local/bin

...On Linux

If you have "root" privileges on your Linux system, you can execute a command like:

sudo ln -s /usr/lib/python2.5/site-packages/django/bin/django-admin.py /usr/local/bin

If you don't have "root" privileges, you can setup your own /usr/local/bin:

mkdir ~/bin

Make sure your ~/.bash_rc contains something like:

export PATH=$HOME/bin:$PATH

Then update your current session with any changes you made to ~/.bash_rc by running this command:

source ~/.bash_rc

And that should do it! Now you should be ready to get started with Django.

Feel free to leave a comment if you're having problems installing Django. Good luck!

Check out Installing Django on Shared Hosting.

Make Your Own iPod-Compatible Audio Books Using Linux

Josh VanderLinden

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I like music a lot. I think I always have, and I probably always will. I like to be able to listen to good music wherever I go whenever I want. Thanks to the wonders of technology, we have a myriad of portable media devices to choose from. I personally chose an iPod nano. It's a wonderful little toy.

Anyway, as much as I like music, sometimes I feel that my time could be better used doing things more productive than just listening to music. Once I realized I felt this way, I began looking into ways to get my audio books onto my iPod. At first I simply transfered over the MP3s that came straight from the CDs. But I soon realized that this wasn't the most effective use of the iPod's audio book capabilities. So the hunt was on for some good Windows software to convert my MP3 audio books into M4B format for the iPod.

Now, I'm a pretty cheap guy when it comes to paying for software (which is probably one of the main reasons I started using Linux way back when). I found a bunch of different "free" tools that claimed to be able to convert my MP3's, but few of them actually worked well enough for me to stand using them. Eventually, I found a (very round-about) routine that allowed me to turn everything into something my iPod could understand as an audio book. I followed this routine to convert several audio books and transfer them to my iPod. I never actually finished listening to any of them completely.

Last night I started fooling around with converting my DVDs into a format my iPod could understand. When I finally got The Bourne Identity converted properly, I tried to throw it onto my iPod from my wife's Mac. It told me that I would have to erase everything (because I used my own PC to transfer my files before), and I said it was ok. I didn't have any of my original .m4b files around anymore, and so I began looking for ways of creating those audio books (in Linux this time).

It wasn't long before I stumbled upon a particularly interesting post on this exact topic. It requires the use of mp3wrap, mplayer, and faac. Pretty simple, really. Here's what you do:

# mp3wrap outputfilename *.mp3
# mplayer -vc null -vo null -ao pcm:nowaveheader:fast:file=outputfilename.pcm outputfilename_MP3WRAP.mp3
# faac -R 44100 -B 16 -C 2 -X -w -q 80 --artist "author" --album "title" --title "title" --track "1" --genre "Spoken Word" --year "year" -o outputfilename.m4b outputfilename.pcm

Nice and easy, huh? Now to decipher it all.

# mp3wrap outputfilename *.mp3

This command will stitch a bunch of MP3 files into a single MP3. This makes it easier to have a "real" audio book on your iPod.

# mplayer -vc null -vo null -ao pcm:nowaveheader:fast:file=outputfilename.pcm outputfilename_MP3WRAP.mp3

This command converts that one big MP3 file to PCM (uncompressed) format. Somewhere in the output of this command, you will see something like AO: [alsa] 44100Hz 2ch s16le (2 bytes per sample) which comes in handy for the next command:

# faac -R 44100 -B 16 -C 2 -X -w -q 80 --artist "author" --album "title" --title "title" --track "1" --genre "Spoken Word" --year "year" -o outputfilename.m4b outputfilename.pcm

Finally, this command turns the PCM file into an audio book (m4b) file. The 44100, 16, and 2 right after faac all come from that special line in the output of the mplayer command.

As much as I like the command line, I don't like having to remember all of those parameters and options. So I decided to create a utility script (written in Python, of course) to wrap all of these commands into one simple one:

# mp3s2m4b.py BookName mp3s_directory [--quality=0..100] [--artist="artist"] [--album="album"] [--title="title"] [--genre="genre"] [--year=year] [--track=number]

While this might still seem too complex for pleasure, it does reduce a lot of the typing involved with the other three commands. All of the thingies in square brackets (like [--quality=0..100]) are optional. My script runs the commands mentioned previously in order, and suppresses all of the scary output.

I've used my script 4 or 5 different times so far, and it seems to work great. You may download it here.

Wireless Networking With SuSE Linux Enterprise Desktop 10

Josh VanderLinden

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Note: This tutorial is a continuation of yesterday's tutorial about installing SuSE Linux Enterprise Desktop 10 on my HP Pavilion dv8000. I may or may not refer to steps that I took during installation, so if you are confused, you might want to check out the previous article.

The process of installing and enabling a wireless adapter will vary greatly from machine to machine. Some lucky folks have wireless adapters that come with official Linux drivers. For the rest of us, we usually have a Broadcom-compatible adapter. In order to use a Broadcom device, I use a program called ndiswrapper, which basically takes the drivers for the devices to function with Windows and wraps them in such a manner that Linux can use. Since I have the 64-bit version of SuSE Linux Enterprise Desktop (SLED) 10, I need to get a 64-bit driver in order for my wireless to function properly. These 64-bit drivers took me a while to get ahold of the first time I got my wireless working (on SuSE Linux 10.1), but I still have them in my archives, so I should be fully prepared to get my wireless working. In this article I assume that you are going to use ndiswrapper to install drivers for a Broadcom device. So let's get started.

Install Ndiswrapper

First, make sure that you have ndiswrapper installed on your system. You can install it by entering YaST. In KDE, click the K menu (the little green chameleon in the bottom left), go to System > YaST (Administrator Settings). You will be asked to enter the root password, which you set during installation. Once you've done that, you will see the YaST Control Center, which is a very powerful set of tools and utilities that greatly ease the configuration and management of SLED. Click on the Software category on the left to show a list of software management options (if it's not already displayed). Click on the Software Management module.

Once loaded, you will see an interface which is very similar to what you would see during the expert package selection while installing SLED. Make sure your Filter (in the top left) is set to Search, and enter ndiswrapper in the search box. The search will return a few different results for ndiswrapper. The first result, ndiswrapper by itself, should be sufficient for most of us. When you check the box by ndiswrapper, you will see a warning informing you that ndiswrapper-based network are not officially supported by Novell. Just click OK to dismiss this warning.

Now you should be ready to install ndiswrapper. Click the Accept button in the bottom right. You will be asked to confirm the installation of ndiswrapper; click Continue. If your installation media is not still inserted, YaST will request the disc which contains the ndiswrapper packages. Insert the disc and click OK. In my case, two packages were installed. It may or may not differ for you.

As soon as the packages are done installing, your configuration settings are saved once again, and you will be asked if you want to install or remove more packages. Click No. At this point, ndiswrapper should be installed on your system, and you may dismiss the YaST Control Center.

Determine Your Wireless Adapter Make/Model

This step is absolutely necessary because if you install the wrong drivers, there is a chance (small as it may be) that your wireless adapter will be damaged. So let's ask Linux how our wireless adapter identifies itself. To do this, log into your SLED and open a Terminal or Konsole. On KDE, you can use the third button (a monitor with a black screen and > on it) on the menu panel at the bottom of the screen, or you can also click the "K" menu (same place as a regular start menu in Windows), go to System > Terminal > Konsole (Terminal Program). I am not exactly sure where this item is located with GNOME, but it might be under the System menu.

Once you have opened a terminal window of some sort, you must switch to a root user environment:

$ su -

You will then be asked for the root password, which you set during installation. Enter that password and type

# lspci

This command lists all of your PCI devices, according to the man pages, but you will see most if not all of your devices, PCI or otherwise, listed here. You'll notice that there is probably quite a list of devices. You may be interested in what your computer has in it, but since you're looking specifically for your wireless adapter, try one of the following commands

lspci | grep Broadcom
lspci | grep Wireless

The | after lspci will pipe the output of lspci to a useful and powerful program called grep. In this case, grep just looks for any lines that contain either the word Broadcom or Wireless. If you don't get any results from either of the two commands above, try to think of other keywords that might be used to identify a wireless adapter. My laptop returns the following:

# lspci | grep Broadcom
06:02.0 Network controller: Broadcom Corporation Dell Wireless 1470 DualBand WLAN (rev 02)

When you find the wireless adapter, pay attention to the numbers in front of it (06:02.0 on my laptop). With those numbers, you can get the information you need to find the right drivers for your particular wireless adapter. Enter the following command, substituting my device numbers with yours:

# lspci -n | grep 06:02.0
06:02.0 Class 0280: 14e4:4319 (rev 02)

This command gives you the wireless adapter's numeric ID; mine is 14e4:4319.

Download Your Device Drivers

Now that you know your device's numeric ID, you can go to the ndiswrapper wiki, which has a list of numeric IDs and the drivers that are known to work with that device. Look for your wireless adapter on the list of devices. I would recommend using your browser's search or find on page function to locate your device by the numeric ID that you just found.

I'll leave the retrieval of your device drivers up to you.

Install The Wireless Drivers

Most device drivers will come in an archive of some sort. Mine came in a RAR file. Extract your drivers to the directory of your choice--maybe something like ~/wireless. You can use the archive utility provided by SLED to extract your files. It functions very similar to WinZip, WinRAR, and other popular archive clients. By the way, the ~ in a directory listing refers to the current user's home directory (/home/user, for example).

Now, go back to the root terminal that you used to determine what kind of adapter you have. Navigate to the directory where you extracted your drivers and list the contents of the directory, looking for any *.inf files:

# cd ~/wireless
# ls

Ndiswrapper will use an INF file to know how it is supposed to install the driver. My INF file is called bcmwl5.inf. Now for the actual installation of the drivers:

# ndiswrapper -i bcmwl5.inf
Installing bcmwl5
Forcing parameter IBSSGMode|0 to IBSSGMode|2

Now check to make sure that the driver is there and that it recognizes your hardware:

# ndiswrapper -l
Installed drivers:
nbcmwl5          driver installed

Ooops!!! It doesn't recognize that my hardware is actually there. If you see 'driver installed, hardware present' then you should be good to go. You may proceed to the next step. However, if you have the same problem as me, you either have the wrong drivers or ndiswrapper installed the drivers improperly. This problem took forever to track down when I was first trying to get my wireless to work. Remember the numeric ID that you found earlier? Check this out:

# cd /etc/ndiswrapper/bcmwl5
# ls
14E4:4318.5.conf  bcmwl5.inf  bcmwl564.sys

Wait a second! Remember how my numeric ID was 14E4:4319? Why is there a listing for 14E4:4318.5? To solve this problem, I am just going to make a symlink (a shortcut) to 14E4:4318.5.conf and call it 14E4:4319.5.conf:

# ln -s 14E4:4318.5.conf 14E4:4319.5.conf

Now when I run the command to see if my hardware is recognized, I get this:

# ndiswrapper -l
Installed drivers:
bcmwl5          driver installed, hardware present

Hurray!! It says 'hardware present' in there!!! That means that the drivers are working and that my device can be used!

Enable Your Wireless Device

With ndiswrapper recognizing your wireless adapter, you can now enable it and start wirelessing your life away:

# modprobe ndiswrapper

There have been times when this particular step will lock up my machine and I have to do a hard reset, but most times it will work fine.

Connect to a Wireless Network

This part also gave me issues for a long time when I first installed my wireless drivers on SuSE Linux 10.1. I was able to connect to the wireless access points provided by my apartment complex, but I could not for the life of me connect to my own wireless router. Hopefully you don't encounter the same problem.

To see what access points you have available to you, check out the KNetworkManager applet in your system tray (next to the clock). I have 7 possible access points listed in the menu, including my encrypted router. When I clicked on my network, it asked me for my passphrase and connected immediately. Nice! That's definitely one plus for SLED over SuSE Linux 10.1!!

I am actually amazed at how easy it was to get my wireless working the second time around. Hopefully your wireless adapter installation was as painless as mine with the help of this guide.