• Kawano – not so Frequently Asked Questions

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• WikiBooks: LaTeX

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• Dive Into Python

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I recently experienced a minor run-in with dpkg-deb. My system tells me, that

$ uname -a
Linux hoazin 2.6.28-16-generic #55-Ubuntu SMP Tue Oct 20 19:48:24 UTC 2009 i686 GNU/Linux

which seems to indicate that the Architecture field of the DEBIAN/control file should read ‘i686‘. Doing this results in the error:

deb Error: Wrong architecture 'i686'

Dismembering official packages reveals ‘i386‘ as the correct value.

The way Rossum Corporation describes themselves is quite scary. Could their internship qualifications sound any shadier?

“New for 2008, the Rossum Corporation offers exclusive 5-year paid internships for candidates of superior genetic disposition. Contact a Rossum Human Recruitment office near you for more details.”

or checking out a specific commit.

First, one has to locate the hash of the commit. This can be done by:

1. Scanning the log by running “git log” (press q to quit). Look for lines labeled commit.
2. Scanning the log in giggle. Look for the SHA-line. Example:
   

In this case our hash is 7f8d2051582dd030e3c07ded70010af033461e31.

Then, come up with a name for a branch to refer the this specific revision. For this example we will use old-branch.

Last, set up the branch by running:

git checkout -b old-branch 7f8d2051582dd030e3c07ded70010af033461e31

Syntax: The general syntax is: “git checkout -b BRANCHNAME HASH“

Since installing Karmic on my laptop, it has consistently failed to connect to the World Community Grid server.

Symptoms: When going the the ‘Messages’ tab of the ‘Advanced View’, one is greeted by lines of the form:

2009-11-05T12:56:47 CET|World Community Grid|Sending scheduler request: Project initialization. Requesting 1 seconds of work, reporting 0 completed tasks
2009-11-05T12:56:50 CET||Project communication failed: attempting access to reference site
2009-11-05T12:56:52 CET|World Community Grid|Scheduler request failed: Peer certificate cannot be authenticated with known CA certificates
2009-11-05T12:56:53 CET||Internet access OK - project servers may be temporarily down.

Solution: After some googling I came across this page, which basically gives a simple workaround:

sudo su
cd /var/lib/boinc-client
mv ca-bundle.crt ca-bundle.crt.backup
wget http://boinc.berkeley.edu/trac/export/16195/trunk/boinc/curl/ca-bundle.crt

I’m not convinced that it will survive an update though.

From time to time one needs to measure stuff on the desktop. You might – for instance – want to know whether some region of an image will fit nicely into some part of a webpage.

In ubuntu (both jaunty and karmic releases) the screenruler application provides an easily available mean to do just that. This application is available through a package of the same name and can be found in the menu under Applications -> Accessories -> Screen Ruler.

The screenshot above shows two instances of screenruler along with the contextual menu (available through right-click or a menu button which appears when the mouse hovers over the ruler). Through this menu the metric can be changed. The length of the ruler can be changed by pulling in the ends and the orientation can be flipped by middle-clicking.

Note: This applies to multiple flavors of Ubuntu; Jaunty as well as Karmic. Also, it might be generic to all distributions based on Network Manager.

At the university we have a eduroam-based wireless network. It has not been very dependable yet; sometimes you can log on, sometimes you cannot. It doesn’t seem to be directly related to signal strength.

It seems that Ubuntu – which uses Network Manager – is quite well suited for this environment. Our setup is based on two laptops; one which can connect to eduroam and one which cannot. These are connected by a standard ethernet cable. The laptop connected to eduroam is then set up to share the connection.

The Guide

First open up the network connections dialog. Do this by right clicking on the Network Manager icon in the notification area and choose ‘Edit Connections …’. In the ‘Wired’ tab, click ‘Add’ to add a new connection. Fill it out like so:

The important parts are

1. The method. This should be ‘Shared to other computers’.
2. The unmarking of ‘Connect automatically’. This will make sure other connections (like DHCP) take precedence.

After confirming this dialog (by clicking ‘Apply …’) the list of network connections should look like this:

Thats it! When you whish to share a wireless connection, click on the network manager icon in the notification area and choose ‘Share Connection’ under ‘Wired networks’.

Update: This no longer works for me. I’m getting the feeling that Facebook might be messing around with the protocol …

The solution for Jaunty seems to have degenerated.

I recently installed Karmic (Koala) Beta and decided to give it a try again. For me, installing the pidgin-facebookchat package and following the instructions at the relevant (bottom) part of the official documentations page regarding protocols. The experience is not entirely stable, but for a beta release I guess it’s ok.