technique

I want to use the latest MeshLab from source because of an annoying bug which makes it impossible to use MeshLab with any locale setting where "," is used instead of "." as decimal separator. Like my German one.

I mainly followed this extensive HowTo: http://meshlab.sourceforge.net/wiki/index.php/Compiling_devel#Getting_the_sources and I used this advise: http://byeworld.blogspot.com/2009/01/libf2cso-undefined-reference-to-main.html

Here you find the most important steps in a short instruction set.

$ sudo apt-get install qt4-qmake libqt4-dev build-essential lib3ds-dev
libbz2-dev liblapack-dev libf2c2-dev libmuparser-dev
$ cd MyWorkFolder
$ svn co
https://meshlab.svn.sourceforge.net/svnroot/meshlab/trunk/meshlab
meshlab
$ svn co
https://vcg.svn.sourceforge.net/svnroot/vcg/trunk/vcglib vcglib
$ wget http://www.ics.forth.gr/~lourakis/levmar/levmar-2.5.tgz
$ tar -xzf levmar-2.5.tgz
$ cd levmar-2.5/
$ sudo rm /usr/lib/libf2c.so && sudo ln -s /usr/lib/libf2c.a
/usr/lib/libf2c.so
$ make
$ mkdir ../meshlab/src/external/lib/linux-g++
$ cd ../meshlab/src/external/lib/linux-g++
$ ln -s ../../../../../levmar-2.5/liblevmar.a liblevmar.a
$ ln -s /usr/lib/lib3ds.a lib3ds.a
$ ln -s /usr/lib/libbz2.a libbz2.a
$ ln -s /usr/lib/libmuparser.so libmuparser.a
$ cd ../../..
$ qmake -recursive meshlabv12.pro
$ make

Now create a little shell script e.g. meshlab.sh and adjust your paths:

#!/bin/bash
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/jan/workspace/meshlab/meshlab/src/distrib
LC_ALL="C" MALLOC_CHECK_=2 /home/jan/workspace/meshlab/meshlab/src/distrib/meshlab "$@"

Make it executable and enjoy

$ chmod +x meshlab.sh
$ ./meshlab.sh

Urgh, got stuck at a bug. Too late to finish it tonight. So here you go with a few bulletpoints of the progress so far.

If you don't use HBCI you might just grab the current stable release since you're not affected by:

http://sourceforge.net/apps/mantisbt/jgnucashlib/view.php?id=18

Else download and extract jGnucashlib:
http://jgnucashlib.svn.sourceforge.net/viewvc/jgnucashlib.tar.gz?view=tar

Make buildme executable:
chmod +x buildme

Change the java path to fit your system. For me it was:
export JAVA_HOME=/usr/lib/jvm/java-6-sun/

Run buildme (takes a few minutes):
./buildme

Open the right file when jGnucashLibGui starts (not in .gnucash/books/ but wherever you actually saved your file)

Be annoyed and give up in the end anyway because of:
http://sourceforge.net/apps/mantisbt/jgnucashlib/view.php?id=19

Good night!

I was suffering from a soundproblem on my fresh Ubuntu Karmic installation. All programs using OpenAL would stop playing sound and start to play scratchy sounds until sound drops completely out. Plus those programs will hang when trying to shut them down. For example OpenArena and Warzone2100 are affected which comes really hard to me

I tried a lot of different things with little success. Most solutions only helped for a moment until the problems came back. I think it's just that it works a little while after a reboot. Basically I don't know what really fixed the problem, but these changes here are in efffect right now and work for me.

1. Add this PPAs and upgrade ALSA to the newest version in there
   sudo add-apt-repository ppa:stesind-alsa-21
   sudo apt-get update
   sudo apt-get upgrade
   


2. Also install the ALSA driver backports
   apt-get install linux-backports-modules-alsa-karmic-generic

Now you should have the newest ALSA running and sound should work again. I also applied some tweaks for HDA intel chipsets but I believe these don't do much of a difference. If you ask me to I'll provide these steps, too.

With the OpneMoko Freerunner comes a stylus which you need if you want to use for example the tiny keys of the keyboard. In general the software I know of is not finger-use ready, yet. So to use a stylus is a good idea. But you have to separately carry the stylus around with you because it's not attached to the phone or has a pocket it goes into whennot in use.

Actually I stole this idea from my friend:

1. Get a friend to give you a guitar pick. Thanks!


2. Get a piece of string. I found a black shoe lace in my moms shoe drawer. Thanks, mom!
   
   


3. Drill a hole in the guiter pick.
   
   


4. Tie the guitar pick to your Freerunner.
   
   


5. Be happy!
   

You might know that I collect Lustige Taschenbücher (LTB) since I was a little kid. I got 258 issues by now and wanted to catalogize them with GCstar to have a better overview. Unfortunately the plugins to automatically fetch all information about the books shipped with it do not cover any webpage listing LTB. That's probably because LTBs are only sold in German speaking areas and thus are only locally popular.

But there is a quite nice webpage listing a lot of them at http://www.lustige-taschenbuecher.de/. So now all I had to do is writing a plugin to grab the data from this webpage and insert it in the database. Something dozens of people already did before me and is documented.

I won't go into details here (I might at some other point in time if someone wants me to) but Perls HTML::parser comes directly out of hell! Anyway, I got it.

If you want to use it as well download the plugin and place it in your GCstar lib directory (on my Ubuntu it's /usr/share/gcstar/lib/GCPlugins/GCcomics/).

 I changed the database layout of the generic GCcomics model a little to make it work with LTBs. See this diff for the changes and apply them to yours or the plugin won't work (most likely the file GCcomics.gcm is to be found at /usr/share/gcstar/lib/GCModels/).

Now start your gcstar, create a new comicbook collection, add a new item, enter the issue number of the LTB as the volume, hit the internet search button, select to query by volume, select the LTB plugin and get happy. I just catalogized my whole collection within an hour. Be aware that some reprints are not listed on the webpage. Especially the early reprints up to about volume 120.

PS: Anyone willing to swap some LTBs with me?

Since a while now I'm trying to figure out the right way of doing backups on my Ubuntu Linux system. I have some requiremtens I want to descibe brefely before continuing.

Don't do regular full backups

I used sbackup so far but it regularly does a full backup, thus taking a long time (I have about 100GBs I want to be backuped) and using up a lot of disk space.

Store the backups on a remote system

Backup basics: keep your backup at a logicaly and spacialy seperate place from your computer. So I want it to work over network and please encrypt the file transfer. And do only send the data of changed files, keeping nettraffic low.

Don't bother me

Work in the background and just do your job. Don't tell me what you're doing unless I ask you to do so. I don't even want to know you exist. The only reason I interact with you is the worst case: I got to restore something.

Easy to setup and use

I want an easy to setup solution which doesn't need complicated settings and extensive care to be kept running. I don't want to change tapes or drives, free disk space tell you that the target is avilable or not, figure it out for yourself and do something sensible. And if I ever have to restore files I want an easy to use interface which enables me to quickly restore everything.

Restoring is also without the backup program easily possible

No, looking inside incremental .tar.gz files is not easy. More like complete snapshots I can browse easily and copy the files I want out of with any basic operating system. But keep the needed needed space low.

Try to backup every little change, ASAP

Most annoying with most backup solutions I think is the fact they only do a backup once a day or similar. With a full backup of 100GBs over the network this might take longer than the longest contiguous uptime of my computer while at home for the day. But I still want pretty much any changed file to be backed up, so I can undo very recent changes.

My solution

I really liked what I heard about TimeMachine from Apple. But I don't use Apple, so I was looking for something similar for Linux. There are a couple of promising projects like TimeVault and FlyBack, if they weren't deserted since about two years.

And there is BackInTime which works fine and is quite recently maintaned (June 2009). It even looks like it's going to be part of Ubuntu 9.10 Karmic Koala (release date Oct. 29th).

So what does BackInTime do that I like it so much?

1. You do one initial backup and then it does only incremental backups.


2. It creates snapshots of your files which you can easily browse without the backup program itself.
   


3. No space wasted through because files that didn't change just got linked in place by hardlinks instead of creating a full copy.


4. It's easy to install and setup. Well integrated into Gnome and KDE desktops.
   


5. After configuration it does not bother me again.


6. You can configure it to create a backup e.g. every 5 minutes.

But it does not store backups on remote systems. Well, you can mount a remote share and do the backup on that one. Luckily BackInTime internally uses rsync which uses Delta Encoding to reduce the amount of data to be sent over the network. But whenever the target is not available BackInTime gets annoying telling me about it every 30 seconds or so. Inacceptable. But there is something you can do about it.

BackInTime is called every 5 minutes by Cron, so I wrote a little wrapper script checking if the target computer is found in the local network and mounting the share prior to calling BackInTime.

#!/bin/sh
#
# Check for server, connect sshfs and start backintime
#

SERVER="192.168.1.1"
SHARE="/shares/backups/myPC"
MOUNT="/var/backups/backintime"
REMOTEUSER="backupuser"

# Is the server pingable?
# try three pings, wait maximum one sec for reply, be quiet
if ping -qc 3 -W 1 $SERVER > /dev/null; then

# check if the remote location is already mounted
# For this check to work the directory 'backintime' should exist in the
# mounted share (backintime creates it during it's first run)
if [ ! -d "${MOUNT}/backintime" ]; then
# make sure the user running this script is member of the "fuse" group,
# has write permission on the mountpoint
# and has a ssh key at the server so he can login without enrering a password
# and can mount this share manually
sshfs -o nonempty ${REMOTEUSER}@${SERVER}:${SHARE} ${MOUNT};
#echo "Verbindung aufgebaut";
fi

# now we have a connection, so let's start the regular backup program
nice -n 19 /usr/bin/backintime --backup-job
# unmount right after using the share
fusermount -uzq ${MOUNT};

else
# just in case there is no connection to the server we try to unmount the share
# be lazy (also unmount busy ressources) and be quiet
fusermount -uzq ${MOUNT};
fi

It's assumed your servers share is accessible via SSH and your user uses SSH keys to log in. There's a good howto on that on Ubuntus help pages.

Save it as e.g. ~/bin/backintimeprep.sh and change the crontab entry to something like

∗/5 ∗ ∗ ∗ ∗ ~/bin/backintimeprep.sh >/dev/null 2>&1

This script is very basic and fails if it finds another server with the same IP address.

Try it out and have fun! I just finished my initial backup and have it running in the background. Hopefully this ended my struggle for a good backup solution.

Using CIFS instead of SSHFS

My slug is very slow and I had a transfer rate of only about 1MB/s whilst totally hogging my CPU rendering it unusable for anything else during a backup. So I was looking for another solution with less CPU usage and better transfer rates.

CIFS is quick and doesn't use much CPU time. But it lacks the security of an encrypted connection which I decided to be negligible in my local network.

I assume you know your way around with samba i.e. how to add users. My /etc/samba/smb.conf on the server looks like this:

[global]
        workgroup = TREEHOUSE
        server string = %h server
        invalid users = root

[backups]
        comment = Backups
        path = /shares/backups/
        read only = No
        writeable = Yes
        write list = jan
        valid users = jan

In the script backintimeprep.sh change the lines for mounting and unmounting the sahres like this.

Mounting:

# you might need to fiddle around with the charset to make i.e. Umlauts work
# this assumes you have a file 'backup.smb' looking like this in your home directory:
#   username=backupuser
#   password=password
# Make sure you set the permissions so only you can read it
smbmount //${SERVER}/${SHARE} ${MOUNT} -o rw -o iocharset=utf8 -o credentials="backup.smb";

Unmounting:

unmount.cifs ${MOUNT};

Works great like this. Much better performance.

EDIT:

• added missing asterisks in crontab


• changed detection if the share is mounted


• unmount the share after using it


• added a section 'CIFS instead of SSHFS'


• changed cronjob to call backintimeprep.sh
  

Recently a couple of services offering online sotrage and a software client for easy synchronisation between several clients, easy sharing and backup came up. It seems like the idea is actually quite old, but as I think really sexy.

I only have a look at DropBox and UbuntuOne here, because those integrate fairly well with my Ubuntu. An incomplete list with similar services can be found at Wikipedia.

There is a nice video at DropBox's webpage explaining what those services are good for, so I won't explain these advantages anymore but redirect you to the video.

Storage size

If I wanted to backup all my valuable data I would need more than 100 GB, which is more than the 50 to 100 GB both services offer to paying customers. But just for quickly sharing files or making some important files available everywhere or similar things the 2 GBs offered by both services are fine.

Service	Free	US$10/month	US$20/month
DropBox	2 GB	50 GB	100 GB
UbuntuOne	2 GB	50 GB	-

Software Clients

While UbuntuOne comes with an open source client which can be trusted, adapted and ported to other plattforms DropBox is a proprietary closed source product. Funnily enough DropBox is also available for Mac and Windows while UbuntuOne isn't, yet. The DropBox client needs some tricks to install on a Ubuntu and probably other Linuxes, too. But in the long run I see a bigger potential in UbuntuOne being ported to anything you could possibly wish for just because it's open source.

Both clients integrate very nicely with Nautilus and enable you via right click to share files or folders. Only details differ here.

Features

Featurewise those clients are not very different either, but the way it works is a little different. There is only one feature I really miss at UbuntuOne and why I use Dropbox. With DropBox you can share files via a simple http link while at UbuntuOne you can only share files when both partners have a launchpad.net account. This is very bad for the very typical situation where you want to send a large file to someone. DropBox's direct link you can obtain by right clicking a file comes in very handy in this use case.

Conclusion

Just now I prefer DropBox over UbuntuOne because of the Windows client being available and not needing any client or account for sharing files via direct weblink. But I predict bigger potential for UbuntuOne because of better integration possibilities with Ubuntu, easier installation and it being open source so there can be clients for any OS and architecture.

After I installed Dspam some time ago I checked on it's accuracy and made a small graph to illustrate it. Since my Dspam installation at Octobre 7th 22 days and 1141 emails passed by. All in all I'm very happy with Dspam. It works just fine and the overall accuracy is 98.51%. I got a false positive rate of 0.79% and a false negative rate of 0.70%. Those emails which got detected wrong were usually emails from persons or companies I never had a correspondence with before. Emails from the same senders were detected correctly after training the filter with the wrong detected emails.

I have a user account on a server which I use for my mail. Unfortunately there is no spam filter set up on the server and I don't have root privileges to install one. So I had to install a local solution running with user privileges utilizing procmail.
In this setup the mail comes from the postfix installation and is forwarded to procmail via the .forward mechanism. Procmail is sending the email via stdin to dspam which returns the tagged email to procmail on stdout. Procmail then sorts the mail into different .maildir folders by examining the X-DSPAM mail headers. The .maildir is then exported as IMAP and some folders are used to retrain false positives and false negatives and to contain spam emails.

I never intended to use the dspam webinterface or the filter training mechnisms via forwarding spam, false positives and so on to certain email adresses of the form spam@... since I can't run perl programs on my web server nor can I set up email aliases.

This is one of many ways to setup dspam. This way is not intended for server installations where you want several users to use dspam. Better try to integrate dspam as a queue in your MTA then.

Postfix to procmail

To forward your mail to procmail edit your ~/.forward to look like this:

"|/usr/bin/procmail"

Procmail to dspam and back

The next step is to configure procmail to pipe the emails to dspam. We'll install, configure and train dspam in the following step.

This is what my ~/.procmailrc looks like:

# Begin spam treatment.
:0fw
| dspam --user vollkorn --stdout --deliver=innocent,spam

# if mail is tagged as spam deliver it to my spam box
:0
*^X-DSPAM-Result: Spam
$HOME/.maildir/.spam/
# End spam treatment.

# inbox catch-all
:0
$HOME/.maildir/

Make sure to change the mail folders to match your setup.

Invoked with the option --stdout dspam returns mails read from stdin to stdout after tagging. --deliver=innocent,spam overrides the default behaviour of putting spam in quarantine. Actually just using spam as a parameter here should be sufficient, but I thought I had to make sure.

Installing, configuring and training dspam

Well, I had to compile from source since I can't use the package management without root priviliges. So download the source and unpack it:

wget http://dspam.nuclearelephant.com/sources/dspam-3.8.0.tar.gz
tar -xzf dspam-3.8.0.tar.gz

Now it's time to configure dspam to make sure all the needed features are getting installed.

cd dspam-3.8.0/
./configure --with-userdir=$HOME/.dspam --with-userdir-owner=none --with-userdir-group=none \
--with-dspam-mode=none --with-dspam-owner=none --prefix=$HOME --enable-spam-delivery \
--enable-delivery-to-stdout

You might want to change your paths but the other options are important. All the user and group related options allow dspam to be run as user. Without the option --enable-spam-delivery all spams would be quarantined no matter what and would have been to be bailed out by cli or webui. I think --enable-delivery-to-stdout is easy to understand as is.

Now compile and install dspam:

make && make install

You'll find dspams config under ~/etc/dspam.conf if you used --prefix=$HOME as I did. There are only minor things to fix since most options are set correctly automagically. Those are the options I changed to fit the setup:

Home /home/vollkorn/var/dspam
TrustedDeliveryAgent "/usr/bin/procmail"
Trust vollkorn
WebStats off
Preference "signatureLocation=headers"  # 'message' or 'headers'
Preference "showFactors=on"
Preference "spamAction=tag"

There are some cronjobs you should set up. So do a crontab -e and enter those lines:

# a cleanup job recommended by dspam
0   0            $HOME/bin/dspam_clean -p
# to rotate the fast growing logs
0 0 $HOME/bin/dspam_logrotate -a 30 -d $HOME/var/dspam/data
# handle false negatives in the specified .maildir folder
*/28               find "$HOME/.maildir/.spam.False Negatives" -type f -wholename "*cur/*" \
-execdir $HOME/.dspam/falsenegative.sh {} \;
# handle false positives in the specified .maildir folder
*/30                find "$HOME/.maildir/.spam.False Positives" -type f -wholename "*cur/*" \
-execdir $HOME/.dspam/falsepositive.sh {} \;

The scripts to handle the false positives and false negatives are quick & dirty so be careful when using them. Remember to change the paths and username.

~/.dspam/falsenegative.sh

#!/bin/sh
# train spams which slipped through the filter and move them to the spam folder
cat ${1} | $HOME/bin/dspam --source=error --class=spam --user vollkorn
mv ${1} $HOME/.maildir/.spam/cur/

~/.dspam/falsenegative.sh

#!/bin/sh
# retrain mail which wrongly got recognised as spam and move them to your inbox
cat ${1} | $HOME/bin/dspam --source=error --class=innocent --user vollkorn
mv ${1} $HOME/.maildir/cur/

So the last thing left to do is to train dspam. After an initial training the accuracy is already very good. It's very important to not only train spam, but also some ham. I trained with 411 spams and about 900,000 hams (no typo).

For training I used these two commands:

find ~/.maildir/.ham/cur/ -name "*" -exec cat {} | dspam --source=corpus --class=innocent \
--user vollkorn \;
find ~/.maildir/.spam/cur/ -name "*" -exec cat {} | dspam --source=corpus --class=spam \
--user vollkorn \;

Results

After using this setup for about 3 days I'm very pleased. Not a single spam made it into my inbox and my mail notification applet went off significantly less. I had one false positive thoug, but it was retrained properly after moving it to the right .maildir folder inside my mail client.

Here is a little pie chart showing the accuracy of my dspam installation.




Ressources

I read these pages and can recommend having a look at them, too.

• http://www.lalkaka.com/dspam/
• http://splodge.fluff.org/docs/single-user-dspam

Yesterday I got a iRiver H10 in return for helping out with a virus infected computer. So the first thing I did was putting rockbox on it. Next step was to make it work with my Ubuntu where I use Rhythmbox.
The Rockbox installation was rather easy though it has some glitches.

1. Connect your iRiver via USB and check if it shows up as USB mass storage device and gets mounted. If so it's a UMS if not it's a MTP player. Don't ask me what these TLAs stand for I just know that you have to choose the right type in the next step. I got a UMS one. For MTP ones you need to use a trick: Remove the battery, put it back in, press and hold the "o" button and then press the power button. It will start up in USB mass storage device. Remember this trick for later.
   
2. Download Rockbox Utility and run the program from the archive.
3. The automatic detection did not work for me so I had to choose my model H10 (5 / 6GB) UMS and my mountpoint /media/H10 by hand.
4. Use complete install to find out you might run into permission problems. Then do a sudo chmod -R u+w <your mountpoint>/System/ to fix this. Now run the complete install again.
5. When your Rockbox fires up for the first time after installtion it's a nice feeling, but the moment hook it up via USB to your computer to upload some files you might get a little shock. USB doesn't work under Rockbox, yet. But no worries, remember the trick from step 1? With Rockbox the player switches off completely so you don't need to take the battery out. Just press and hold "o" while switching the player on and it fires up as a USB mass storage drive. You have to do this whenever you want to connect the player to your computer until the bug is fixed.

The next problem was to get Rhythmbox to work properly with the player. The problem is that the path for the files to store is not recognised properly by Rhythmbox. This can easily be fixed by creating a file in the root of the player

.is_audio_player
audio_folders=Media/Music/,"My Recordings/"

This is it. Works fine for me.

This is my first test with a google map. I got paths and pictures, can click on them, they are embedded in my blog and everything basically works. In this example it's only 20 pictures and it might not be possible to use more than 50 pictures and they are all off place and there are two paths from two days in the map, but this is just some quite random test data I didn't prepare well.

Well there are some problems left like the way I upload the pictures wherefor I have to create a nice workflow which integrates well with the software I use and the way I manage my photos. Right now it's just too much work and I create duplicate pictures and so on. And after puting the iframe for the map into an article of this serendipity blog I can't edit this article anymore. Just goes crazy and doesn't save any changes anymore.

Probably within the neyt week I will be able to show some maps with my entries. Then I will explain how I produced them and all the details. Not too exciting actually.

btw: this entry might not work anymore after I cleaned up my webserver and have a proper workflow for my maps.

View Larger Map

Since I had problems with the built-in gallery of serendipity, like the thumbnails were square and thus stretched or the UTF8 encoded comments were not shown properly, I switched to gallery2. This gallery works fine and is even integrateable into serendipity. Plus it has a remote plugin which allows other programs to upload pictures directly. Like for example f-spot which I use to organize my photos. Pretty nifty just to click something like "upload" and a moment later all the pictures you had marked are uploaded in your photo gallery. OTOH I had to break the sophisticated security features of gallery2 in order to present the pictures in the right way as needed by the google maps overlays I generate for my travel routes with integrated pictures.

"Gallery2" vollständig lesen

Unfortunately the usergallery plugin for serendipity which I use doesn't handle Unicode User Comments of EXIF headers properly. So the comments are pretty much unreadable (have a look on any picture in the gallery) but I filed a bug report. Hopefully there will be some solution. If so you'll be informed about that here and advised to go through the pictures again to read all the nice comments .