Category: Blog

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Computers Linux

Unicast to broadcast

Unicast to broadcast

Sometimes it might be beneficial to redistribute unicast UDP traffic to multiple other clients. I tried to accomplish this using iptables but it doesn’t seem to be able to resend the packets to the local broadcast address.

This program provides a solution to this problem. It listens on a specified UDP port on all local addresses and resends those packets to the local broadcast address. To avoid creating a loop the incoming and outgoing ports must be different. The application can also ensure that only packets coming from a specified source are being retransmitted. While the latter doesn’t provide any real security since it is trivial to spoof the source IP address, it does provide some immunity from other applications.

The source code for the application (uc2bc) is included in the gzipped archive below. Just compile with “gcc -o uc2bc uc2bc.c”. A sample init script is also included. This would go in the /etc/init.d folder.

Thanks to Andreas who got me (re)started with socket programming on *NIX.

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Computers Gadgets Music

Using iPod Touch as SqeezeCenter remote

I bought an iPod Touch a couple of months ago on the assumption that it would be an ideal remote control for my SlimServer setup. Unfortunately, there was no theme tailored for the screen size of the iPod Touch (or iPhone for that matter).

With the upgrade to SqueezeCenter, it is possible to add a theme called iPeng that is fantastic for the iPod Touch.

SqeezeCenter-iPeng

Suddenly, the iPod Touch is every bit the remote control I was hoping it would be. A big thanks to Joerg Schweider, aka Coolio.

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Computers Linux Music

SqueezeCenter 7.0 is out!

Finally! I have been running SlimServer 6.5.4 for a long time and it was time for an upgrade but SqueezeCenter, the promised replacement for SlimServer, just never seemed to materalise. Sure, the development branch has been available for some time but for once I wanted to hold on until the real thing was out.

SqueezeCenter 7.0

And now it is here. Logitech released SqueezeCenter 7.0 yesterday. The upgrade from my previous installation of SlimServer 6.5.4 on Ubuntu 7.10 was very straightforward. I just did:

# apt-get update
# apt-get remove ––purge slimserver
# apt-get install squeezecenter

The effort is well worth it. I have just barely started using the new interface but it is much slicker and also feels a lot more responsive.

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Computers Linux

Networking lost when cloning Ubuntu image

I use Microsoft Virtual Server 2005 R2 to host a couple of server. I have become accustomed to having template virtual machines so I don’t have to start from scratch for every installation. When I did that to a newly installed Ubuntu 7.10 I immediately noticed that I lost all networking.

It turns out that Ubuntu 7.10 has moved some settings for MAC address mapping for interfaces to the file /etc/udev/rules.d/70-persistent-net.rules. Edit that file and make sure that the MAC address matches the MAC address given by the virtual host.

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Computers Linux Windows

Reducing clock drift in Linux 2.6 under Virtual Server

The combination of Ubuntu 7.10 (or any other 2.6 kernel based Linux distribution) and Virtual Server 2005 R2 leads to extreme clock drift, causing the clock in the guest operating system to drift several minutes per hour. This amount of drift is beyond what NTP can normaly cope with and while some people have advocated running ntpdate as a cron job every hour, such an remedy would only reduce the issue since it would drift many minutes before it would be reset again.

Microsoft has issued a knowledgebase article that describes a solution to the problem.

In short, add “clock=pit” to the kernel options in /etc/grub/menu.lst.

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Computers Linux

Installing Ubuntu 7.10 on Virtual Server 2005 R2

I was trying to install Ubuntu 7.10 on Virtual Server 2005 R2 and was continuously met by an error saying “your installation CD-ROM couldn’t be mounted”.

Ubuntu CD mounting error

It seems that every time I try to install Ubuntu, I run into problems. Last time it was caused by lack of hardware support in the CPU on my VIA motherboard for some compiled-in feature. That was solved by using “alternate” build. In this case it seems to be a mismatch between my version of Virtual Server and Ubuntu. What worked this time was to use a minimal installation ISO which pulls down the rest of the installation over the network. This still doesn’t make the CD work but I have no use for the CD in this specific installation so that is fine by me.Sidenote: The same version worked flawlessly in VMWare Fusion. Lessons learned?

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Computers Mac

Vanishing icons on Mac OS X

Every once in a while the icons on my desktop suddenly almost disappear, leaving just the text underneath and a very tiny border where the icon should be.

Lost icon problem

The first time this happened I was quite perplexed and just couldn’t understand what I had done or how I could get the icons back. I tried rebooting but it was of no good. Then I realised that the only icons that were affected were shortcuts from Safari. Apparently, the icon cache gets messed up and needs to be fixed. The solution is simple:

  • From the Safari menu, select “Reset Safari”
  • Mark the option to remove all website icons and click “Reset”
  • Finally, Finder needs to be reset. Either log out and back in or press option-command-escape and relaunch Finder.

Lost icon solution

Categories
Computers Mac

Fix Perl locale warning on Mac OS X 10.5

With the default settings on a Mac OS X 10.5 system, perl scripts will issue a warning that the locale has not been set properly. The warning will look similar to this:


perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LC_ALL = (unset),
LANG = "UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").

To fix this issue, create a folder in you home directory called .MacOSX (if it doesn’t already exist). Create a text file in that folder, calling it environment.plist and giving it the following content:


<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist SYSTEM
"file://localhost/System/Library/DTDs/PropertyList.dtd">
<plist version="0.9">
<dict>
<key>LANG</key>
<string>UTF-8</string>
<key>LC_ALL</key>
<string>C</string>
</dict>
</plist>

You then need to log out and back in again for the changes to take effect.

Categories
Gadgets Photography

Warning: Nokia update wrecks Lifeblog

On January 25th Nokia Beta Labs published Share Online 3.0, an update to the media sharing services in the phones. Do not apply this upgrade if you want to use additional service providers than Flickr and Vox, such as lifeblog4wp. After applying the upgrade, the service provider list is back to the default two entries and any additional service providers will be removed. What is worse, there appears to be no way to add them as the entry “Add Service Provider” has been removed from the menu.

The application to watch out for is Share Online ver 3.0.07.51 for Series 60 version 3.1. I seriously hope this is just a mistake on Nokia’s part and that it will be fixed in any upcoming stable release.

If you have installed the upgrade it does not appear to be enough just to remove the application from the Application Manager. So to get back to the previous functionality the phone must be restored to factory settings by typing *#7370# and entering the security code (default 12345). You will lose all your settings and content.

If you despite of this want to get this upgrade it can be downloaded from here. You have been warned.

Categories
Photography

Nokia releases geo-tagging software

Both Nokia N95 and N82 have built-in GPS receivers but until now Nokia has not integrated that function with the camera. Yesterday, Nokia released an application called Location Tagger through its Beta Labs that does precisely that.

Once installed, the application icon turns up in the application folder. The application is very simple and by just running it and putting it in the background. The status of the GPS reception is shown by a small icon at the top of the display. The application will maintain its location through the GPS receiver and automatically store the position as EXIF data in the image files. Other applications can then use that information for different purposes, e.g. to show where the images were taken on a map.

The GPS receiver in the phone is known to be quite good at draining the battery in no time. Luckily, the Nokia developers have thought of this and the application automatically turns off the GPS receiver after a couple of minutes after the last picture is taken. By default, this period is set to five minutes.

Below is a dump of EXIF tags on a picture taken by my Nokia N82 with Location Tagger.

Location Tagger

Location Tagger can be downloaded from here.

Now, I just have to adapt my WordPress photoblog to be able to show the position and link to Google Maps.

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