2009.09.03

Rules for How to Write Cross Platform Code

After reading this interesting blog about creating petabyte size storage servers I found this entry about rules to follow when writing cross platform code by Brian Wilson to be a good read for anyone doing cross platform coding in C/C++ (or any language for that matter).

The author works for Back Blaze which seems like a nice inexpensive backup service. I will probably subscribe to their services once they have a Linux client. It is a little hard to ignore the irony of the cross platform article when the Linux client is still missing, however, anyone that has worked for a software corporation knows there are often many other non-technical reasons for their product release decisions.

There are 10 types of people in the world: those who understand trinary, those that don't, and those that confuse it with binary.

2009.08.21

Apache 2 Web Server Configuration

I finally got my site backup up and working on a new server. A very quiet Dell Studio Slim 540s, running Ubuntu 8.10 and apache 2. I had been running apache (1) on an old hand built Celeron 500MHz server that made a lot of noise and had some hard drives dying. It was long over due for an upgrade.

Installing Ubuntu 8.10 was easy enough as was moving subversion over (it was the first thing I did). All I needed to do for subversion was to rsync the directory over along with all of the other files I was copying, and start the service. Once I had my ssh keys setup, subversion worked just like it did on the old server.

Getting apache to work correctly, however, was not nearly as easy. The server itself worked fine out of the box, but I have a lot of domain names that I proxy with apache and it took me a while to figure out how to set those up correctly. After looking at far too many examples online I finally got it working. The following are the steps I took, and hopefully this will save someone else the time it took me to figure it out. Note that all of these commands need to be run as root or via sudo.

First I added some needed modules:

a2enmod proxy proxy_connect proxy_http proxy_ftp userdir

Then setup the proxy configuration by editing /etc/apache2/mods-available/proxy.conf:

<IfModule mod_proxy.c>
        ProxyRequests Off

        <Proxy *>
                AddDefaultCharset off
                Order deny,allow
                Deny from all
                Allow from all
        </Proxy>

        ProxyVia On
</IfModule>

I did not need to make any changes to the default userdir.conf.

Now create a site file for every site you run. Here is mine for nulldot as an example:

Edit /etc/apache2/sites-enabled/nulldot:

<VirtualHost *:80>
    ServerName nulldot.org
    ServerAlias nulldot.org *.nulldot.org

    ProxyPass / http://localhost/~kyle/blog/
    ProxyPassReverse / http://localhost/~kyle/blog/
</VirtualHost>

Obviously, replace nulldot.org with your domain name and point the ProxyPass and ProxyPassReverse lines to your target directory.

Then enable the site with:

a2ensite nulldot

Now restart apache2 and hopefully everything works:

/etc/init.d/apache2 restart

Getting information off the Internet is like taking a drink from a fire hydrant.

— Mitchell Kapor

2008.06.27

Negroponte Unveils an OLPC Laptop E-Book

Negroponte of OLPC fame, unveils the 2nd Generation OLPC Laptop, which is an E-Book. I'm not sure I'll get one (or even if I'll be allowed to buy one 1), but I like the idea. I'm still quite happy using my Gemstar (RCA) REB 1100 for all of my e-book needs.

While I like what the OLPC organization has done and continues to accomplish, there are a couple sticking points for me. First, their laptop is very under powered by today's standards. Although that is probably fine for their intended audience, it does make me not want to own one myself. Plus if you use it as intended, you're using their SUGAR interface which is new and limited — in the sense that you can only run applications specifically designed to run under SUGAR.

Some great things have come out of the OLPC project. They were very innovative with the display technology, which requires a lot less energy to power than normal laptop screens. Also, their mesh network concept seems like a good idea.

On a bad note, they've recently decided to support Windows on the OLPC devices, which I think is a very bad idea. A main point of the OLPC project was to foster openness and freedom, two ideals that Windows does not support — at least from a technical perspective.

On the e-book topic, researchers at Maryland and Berkeley Universities have created an interesting e-book reader that lets you flip the pages. That's a feature I don't think I need or want, but it's interesting.

1. The original OLPC laptop cannot be bought directly. You may buy them for children in other countries, or donate to the project only.

Dew knot trussed yore spell chequer two fined awl mistakes.

2008.06.23

Purity Comic

Another great entry from xkcd. I remember a real version of this science scale presented to me in college, but the professor labeled the sciences on the left as weak sciences and the ones on the right as strong sciences. It seems that Engineering and Computer Science have been left off — on purpose I suppose, since they would be pretty close to Mathematics and thus ruin the joke.

Change is the essential process of all existence.

- Spock, "Let That Be Your Last Battlefield", stardate 5730.2

2008.01.29

How to Get Started Learning Emacs

I do realize that I'm probably quite biased on the topic of editors, but be that as it may, Emacs is simply the best editor, IDE, environment, platform, lifestyle, etc. there is. And it's high time you learned how to use it.

First a quick aside... I used vi and vim for 10 years or so before I finally decided to bite the bullet and take the time to learn Emacs. It probably took me 6 months of playing with Emacs to really get comfortable with it. Hopefully these suggestions will help lessen that amount of time for others.

I'm assuming that you can figure out how to find and install Emacs for your system. You may read how to obtain Emacs from the GNU Emacs site.

...

Here are some good sites for more information about Emacs:

The problem with the GNU coding standards is they ASSUME that everyone in the world uses emacs. If that were the case, free software would die because we would all have wrist problems like RMS by now and no longer be able to code.

- Knghtbrd

2007.12.25

ASUS EEE Sub-Notebook PC

ASUS makes this pretty cool looking sub-notebook PC called EEE PC. Even though this computer has been out for a while, I just recently learned of its existence. It seems like a good competitor to the OLPC.

It has a 900MHz Intel CPU, either 256MB, 512MB, or 1GB of DDR2 RAM, and either a 2GB, 4GB, or 8GB flash drive depending on the model. They all have a 7 inch screen with 800x480 resolution and built in 802.11g wireless. With no moving parts for the hard disk, this PC should be very quiet.

It comes installed with a customized version of Xandros Linux which can be updated from Debian repositories. It can also run Windows XP, which can be purchased for $40. The default install boots in (a very impressive by today's standards) 15 seconds.

Even though the price range was supposed to be in the $200 to $300 range, it seems that the middle range models are selling for around $400 at Amazon and Best Buy.

WikiPedia has more information and here are some reviews that go into more details about the device:

I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve.

- Bilbo Baggins [J.R.R. Tolkien, "The Fellowship of the Ring"]

2007.12.11

Android Software Development Kit

Google along with The Open Handset Alliance has released their very cool software stack for mobile phones. There is a lot of hype behind this project and a lot of people think it will be the next big thing for mobile phones. Personally, I'm very excited for the future of mobile phones as they go away from being a closed and tightly controlled environment to an open one.

Here are a few videos introducing Android:

If you are interested in programming for the Android platform it is very easy to get started. Download the SDK and follow the instructions. I recommend using Eclipse with the Android Plug-in. It comes with some example applications that are interesting to look at.

Here are some videos that give a technical overview and a programming example:

I've mentioned the OpenMoko and Qtopia Greenphone projects before, which have similar goals, but lack the backing and hype that Android has.

I worry about my child and the Internet all the time, even though she's too young to have logged on yet. Here's what I worry about. I worry that 10 or 15 years from now, she will come to me and say "Daddy, where were you when they took freedom of the press away from the Internet?"

- Mike Godwin, Electronic Frontier Foundation

2007.10.26

Exploits of a Mom Comic

As a database developer I found this comic to be hilarious. It was also a good excuse to mention the very funny (at least to geeks) comic strip xkcd.

Some other notables:

Today is the last day of your life so far.

2007.10.21

Rockbox Open Source Jukebox Firmware

After hearing me complain about Apple's move to deliberately block non approved software from interfacing with their iPods, a friend/coworker of mine recommended I try running Rockbox on my iPod Photo. So about a week ago I installed it and gave it a try.

It was easy enough to install, although I couldn't get the RockboxUtilityQt installer to work. I followed the directions on installing manually from Linux, copied the files to my iPod's root directory, ran the ipodpatcher program to install the new boot loader, then rebooted my iPod.

I found Rockbox intuitive to use, and so far everything just works as I would expect. It has different font themes including one that looks like the original iPod font. It plays music very well, has play lists, and a bunch of fun games. It supports over 15 codecs, including MP3, Ogg, AAC, WMA, Real Audio, etc. Also, it coexists with the normal iPod firmware, so you can switch back at boot time if you like.

I haven't played around with the play lists yet so I don't know how they compare with Apple's Smart Play Lists that I've become addicted to. One nice feature is that you can create play lists and name them on the iPod itself.

There are many features that improve upon the regular iPod firmware. For example, the volume has more range and goes a lot louder. The buttons have more functionality — combinations as well as long presses do different things.

I have noticed one thing that might be a show-stopper for me... battery life is awful when running Rockbox. However, this is a known issue and a fix is in the works.

CNET has a nice write-up of Rockbox.

Don't be trapped by dogma — which is living with the results of other people's thinking.

- Steve Jobs

2007.09.27

Qtopia Greenphone from Trolltech

I just read this article in Linux Journal about Trolltech's new Greenphone and the Qtopia SDK it comes with. It looks like yet another Linux based cell phone is coming on-line. This can only be good for the Linux community trying to have cell phone options and compete in a cell phone world of corporate control and commodity hardware. linux.com also has an article about the phone.

It looks like Trolltech is only targeting developers for the time being since you can only buy the phone with the SDK. You may choose from the Professional, Light, or Community (GPL) versions. With prices ranging from $695 and up.

The specs include a Marvell PXA270 312MHz CPU, 64MB RAM, 128MB Flash, 320x240 QVGA touch color screen, Mini-SD card slot, Tri-band GSM, Bluetooth, and a 1.3 mega-pixel camera, with Qtopia running on Linux kernel 2.4.19.

Even though the Greenphone looks pretty sexy, it's pricy for what you get. Plus after reading some of the reviews it seems to have some hardware issues. I think I'll stick with my plans to get an OpenMoko device for now.

Agent Gates: I hate this place. This GNU. This open source. This license, whatever you want to call it. I can't stand it any longer. It's the free software, if there is such a thing. I feel saturated by it. I can taste your GPL. And every time I do, I fear that I've somehow been infected by it.

— fishbonez