Henning Mersch - Tech Blog

Old Skool...

From IRC - #k-9 @ freenode (10/8/22, anomymized), I am <HM>...

<F>HM: if you have a custom ROM with proper iptables support, you could use DroidWall to prevent K-9 from using non-WiFi connections
[...]
<HM>F, *g* I lika that .... cracking a nut with a sledgehammer
<F>;)
[...]
<HM>.oO(I worked with iptables maybe 10 years ago...and I never thought I could use this knowledge on my mobile somdays)
<T>I've seen ".oO(...)" 10 years ago and I never thought I'd see it again. ;)
<HM>ROTFL
<T>wow, and a T in "rofl".
<T>You ARE old skool.

Well, Thanks, I know I'm getting old ;-)

Ubuntu Lucid Update

Couple of days ago, I updated my machines to Ubuntu Lucid 10.04. Everything works really smoothly: Hardware is recognized and supported, no issues with my xrandr-dual-screen as well as my homesticksyncing.

Well, KDE got one BIG, LARGE issue. Just google for Akonadi self-test failure.

The Akonadi server is a information server under the hood of KDE - mostly used by the sematic desktop stuff. Prior update I switched the Akonadi server to use a local mysql server for saving some resources. As suggested here, this is done my checking the Akonadi option "Use internal MySQL server". Well, the new version seems to NOT support this option - the server cant start and due to this some KDE applications like kmail and kontact (which I used) cant start up. Even worse: Since the server cant start, there is no GUI to uncheck the "Use internal MySQL server" option!

Afer some investigation and reading this, I figured out a semi-perfect solution: One can simply delete ~/.config/akonadi/akonadiserverrc, which seem to store the "bad" configuration. After deletion, the server could be started but all kontact data seems to be lost. Luckily, this could be imported from "~/.kde/share/apps/kabc", which seems to be the old place for addresses.

This story really gives me to think about KDE as a integrated desktop environment....

Chrom(ium|e) and Anonymity

Some time ago, I wrote here...Sorry!

T'day I had a look at Chrome and Chromium as alternative to Mozilla's "the one" Firefox Browser. And I must state that I'm very disappointed: Some functionality, which is quite "normal" for my every day browsing behaviour is missing. Especially some Buttons for quickly "disable referer sending" (for Firefox I use RecControl extension) and "per-site and default Cookie-Behaviour" (for Firefox I use CookieButton) are missing.

As far as I found out (googling and reading maillist-discussions) there is currently no concept for extension-http-request-manipulation, which makes it impossible to realize thus things as extensions. Scary...

Anybody has a hint on this?

Nintendo's missed chances for the Wii

Currently I have some spare time to waste, thus I had a more closer look at (unofficial) developments around my favorite game console: The Nintendo Wii.
Nintendo has done a great job while developing this piece of hardware and esp. motion controllers - which is prooven by their business stats and sales counts. But... what is possible now because Nintendo hasen't developed (or at least released) own products / fireware features?

Just a short list - all this is possible now without any hardware modifications like a modchip:

DVD playback: Yep, the Wii has a DVD drive and no support for watching DVD movies. Sounds strange? Maybe Nintendo saves some ct while not buying a license? Nevertheless this is one of the most logical enhancements which were implemented - simply by porting the famous MPlayer (and a special lib ;-) )to the Wii.
USB-Storage support: Two USB ports on the back and everything which could officially conencted is a keyboard. Well...inofficially any USB stick or hdd is used.
Speed up game loading: By dumping the games to HDD one also hasn't to change the DVD within the drive :-)
SDHC-support: Officially just SD cards within the front slot are supported, but inofficially any (cheaper and bigger) SDHC is working.
Homebrew capabilities: A huge, huge range off games has been ported to the Wii as open source or at least for free. The development of executing own code at the Wii's processor was definetly ths foundation for everything else.
... many many more details.

I'm really shocked that Nintedo missed this - I thought they would release firmware updates a a certain point for enhancements like other game console companies does ...but anyway: Thanks Nintendo for the great hardware :-)

Ubuntu 8.10 / Intrepid hint: Xrandr

One of the most annoying challenge while upgrading Ubuntu was the usage of Xrandr of Intrepid / 8.10.

As some of you might know, I love to use two screen, which was done by Xinerama within xorg.conf before. This has changed! Xrandr allows dynamically change of the layout during runtime by command line sth. like this:

xrandr --output DVI-D_2 --auto --output VGA_1\
--mode 1280x1024 --right-of DVI-D_2

(just type "xrandr" and have a look for your screen names) Fine - but: Do I really have to start this command every boot? No! A lot of forums suggest to write a /etc/init.d script, which is executed during boot - doesnt work for me! But I read at thinkpad the real solution (in my optinion): Xsession script at login-time.
Here is mine, which has to be put to
/etc/X11/Xsession.d/45custom_xrandr-settings

------------
# from 
# http://www.thinkwiki.org/wiki/Xorg_RandR_1.2
# If an external monitor is connected, place it with xrandr

# External output may be "VGA" or "VGA-0" or "DVI-0" or "TMDS-1"
# radeon EXTERNAL_OUTPUT="VGA-0"
EXTERNAL_OUTPUT="VGA_1"
EXTERNAL_OUTPUT_MODE="--mode 1280x1024"

INTERNAL_OUTPUT="DVI-D_2"
# EXTERNAL_LOCATION may be one of: left, right, above, or below
EXTERNAL_LOCATION="right"

case "$EXTERNAL_LOCATION" in
       left|LEFT)
               EXTERNAL_LOCATION="--left-of $INTERNAL_OUTPUT"
               ;;
       right|RIGHT)
               EXTERNAL_LOCATION="--right-of $INTERNAL_OUTPUT"
               ;;
       top|TOP|above|ABOVE)
               EXTERNAL_LOCATION="--above $INTERNAL_OUTPUT"
               ;;
       bottom|BOTTOM|below|BELOW)
               EXTERNAL_LOCATION="--below $INTERNAL_OUTPUT"
               ;;
       *)
               EXTERNAL_LOCATION="--left-of $INTERNAL_OUTPUT"
               ;;
esac

xrandr |grep $EXTERNAL_OUTPUT | grep " connected"
if [ $? -eq 0 ]; then
    xrandr --off --output $INTERNAL_OUTPUT --auto \
    --output $EXTERNAL_OUTPUT $EXTERNAL_OUTPUT_MODE $EXTERNAL_LOCATION
else
    xrandr --output $INTERNAL_OUTPUT --auto \
    --output $EXTERNAL_OUTPUT --off
------------

Beside this, there were a lot of pitfalls and bugs I came across - maybe enough stuff for another post. For now you just might have a look at my continuous growing list of subscribed bugs of Ubuntu's launchpad. From my point of view the worst Ubuntu release ever!

Windows users coming to Linux ...

Last weeks couple of people get ultimatively frustrated about their so called operating system Windows. As some of you might know I always help people coming from the dark side, but this time ... some remarks where hard to explain to non-computer freaks ;-)

This helped me out:
A really nice page about the expectations, problems and a general remark on THE CHANGE. And still true:

Linux is Not Windows

(and hopefully will never be!)

Es gibt auch eine deutsche �bersetzung:

Linux ist nicht Windows

Impossible: Secure Mobile Mail Reading w/ Nokia S40 (6233) and self-signed CA certificate

Last time I wrote about the cheap'n'easy web access via my old Nokia 6233 and the eeePC.

Next challange: using the build-in eMail program to read mail via imap(ssl) - for fast eMail checks.

Well - impossible with this Nokia 6233, at least if your imap server has a certificate of an self-signed CA (like cacert.org or your own CA). S40 based mobiles seem to require the CA certificate for import to be in WPKI format - rather than S60, which accept X.509/DES - and I could not find any (free) converters.

Does anybody know one?

Here are some links, I found interesting:

http://browndrf.blogspot.com/2006/06/build-and-install-singed-midlet.html

http://www.redelijkheid.com/index.php/2007/06/03/installation-root-ca-on-nokia-e61-made-easier/

Sometimes one figures out how bad products are...years after buying them :-/

eeePC and mobile internet

Mobile internet gets cheaper and cheaper. On business trips sometimes it would be fine to read mails...

So - Flatrate? No way - I'm on the road for 2-3 days per month, thus a prepaid card (24ct/MB with 10kb parts at nearly all of the prepaid cards) with an old mobile seems to be the choice.

After configuring the mobile via SMS of my provider and selecting the packageservice it was really easy to establish a connection using my eeePC running Xandros:

Plug in the mobile via usb
create new Connection
select dialup (wait a bit)
configure dialnumber and username/passwort
Thats it! It worked out of the box!

Great!

Ok - the details for my specific setup:
eeePC 701, Nokia 6233, USB Cable CA-53(shipped with the 6233), Blau.de Prepaid Card

CleanHome v 0.5 @ Google App Engine

Last days I read an articel about the Google App Engine and decided to have a closer look - really amazing simple and powerful! Immediately I decided that this would be the right hosting solution for CleanHome's remote database including a view/submit webinterface.

After some hours of implementation (even without any experience of Python) its done: CleanHome v0.5! While doing this I decided to shift the whole homepage to this page, thus we have everything at one place.

Thanks Google - thats another brilliant done job!

PS: Source of the Google App as an example is commited to SVN like all other source code of CleanHome!

New Project: CleanHome

...clean your $HOME the easy way!

Usually you don't see them, but every program you give a try is saving user preferences within your $HOME directory - it polutes your Homedirectory!
Over the years my $HOME grew and grew - mostly by old .-Files and .-Directories. Last weekend I had a detailed look and thought: Well - too bad! Need to clean up - but .. is ".xyz" really important? Where does it come from?

I ended up with writing a pluggable Perl program providing me information from apt, showing me last modification and so -- CleanHome was born.

After I read some posts like this, I decided to release CleanHome to publicity - hoping that people will contribute to the main part: The knowledge database about which .-File/Directory belongs to which application.

A first release does exist, thus give it a try!
Would be glad to get some feedback about the idea, input to the knowledge database or even additional plugins!

Further information and download at the (temporary) Homepage.