Saturday, December 30, 2006

Header changes to improve reading

Hello World,
today I changed the blog header erasing the old and uselees links to Downloads and Wallpapers that I never used (I haven't had the time to keep them updated!). In that place I put three direct links to three labels. So now you can easily browse two more blogging categories such as Thoughts and Comments and one monographic label that will display all the post about Linux.
So if you are here to read something you should choose Thoughts or Comments, if you are here to view something related to linux then click to that label.
I hope to have improved reading in this small part of the blogosphere! Tell me what you think about that!
Good night,

PS: now I changed also the background colors, now it's too professional? Tell me your opinion!

Thursday, December 21, 2006

Linux Conference at Politecnico di Milano

This afternoon MacTeo and me took part to the conference about Linux and OpenSource software, helping the organizer's committee of the student organization the POUL "Politecnico Open Unix Labs" and "La Terna Sinistrorsa". We held two stands to show our system from KDE style on KuBook to the powerful of an hacked set of MacOSX on Teo's iBook!
We till february are will experience some troubles due to the exam session, but we are thinking about cool ideas we hope to succeed to develop and to post to BiteComputers blog!

Sunday, December 17, 2006

Google Talk with Kopete

Minutes ago I configured GoogleTalk with Kopete and because half of this tutorial on seems to be broken I'm posting some advices to get it work based on my experience...

Install Kopete and check that the secure connection packet is properly installed on your distro. Direclty from that tutorial here it is a list of that packet's name by distro:
  • SUSE: the package is called "qca" but is installed by default along with Kopete.
  • Debian: the package is called "qca-tls".
  • Fedora Core 4: the package is called "qca-tls" and is available via yum from the Fedora Extras repository.
  • Gentoo: the package is called "app-crypt/qca-tls". use 'emerge qca-tls' to install
  • Mandriva : just install "libqca1-tls"
  • Slackware: install qca-* packages from and then run ldconf as root.
  • Kubuntu: the package is called "qca-tls" and is installed by default.
There is a communication issue between GoogleTalk windows client before version and Kopete older than 0.11 so be sure to have installed Kopete 0.11 or newer

Let's create Google Talk account:
  • create an account with the Jabber protocol
  • as user ID write your gmail address (if you don't have a gmail addres ask me in the comments for an invitation)
  • use your gmail password
  • go to the next screen
  • activate the flag to use SSL
  • allow plain-text password
  • select the option to overwrite default server information
  • set as server "" port 443 (to it works only with this, tutorial says to try 5222 before)
If you get the following message:

The certificate of server could not be validated for account The Certificate Authority is invalid.

the tutorial says to change the server from "" to ""; this doesn't work to me... I simply closed the warning asking not to view that message the next time, this is the only way in whinch I can connect to the server.
GoogleTalk's power is that you will view your friends as online either when they are using the GoogleTalk cliente either when they are connected to their gmail account using the web interface! So you will be able to send messages that will be prompted out by gmail's chat plugin on the web page!


see ya!

Saturday, December 16, 2006

Matlab Symbolic Toolbox on Linux - GLIBC_2.0 issue fixed also on kernel 2.6.17

Hi folks!
First of all I have to thank slackwarelife and Anonymus (I hope he will post me his nick!) to have posted on their comments two sources for the solution of MATLAB's Symbolic Toolbox issue with the not found GLIBC_2.0!

If you are on this page you are probably trying to fix this:
Unable to load mex file: /usr/local/matlab7/toolbox/symbolic/maplemex.mexglx.
/usr/local/matlab7/bin/glnx86/ symbol errno, version GLIBC_2.0 not defined in file with link time reference
??? Invalid MEX-file '/usr/local/matlab7/toolbox/symbolic/maplemex.mexglx': .

Error in ==> maple at 104
[result,status] = maplemex(statement);

Error in ==> sym.maple at 85
[result,status] = maple(statement);

Error in ==> at 22
X = maple(A(:),'+',B(:));
We got a solution with a strange method: setting the global variable LD_ASSUME_KERNEL to 2.4.1 avoiding libmaple's call to GLIBC_2.0 that caused the crash.

On kernel 2.6.17 (for the Ubuntu-users as I am it means from Dapper to Edgy) this trick doesn't work anymore because with the new kernel setting that variable to 2.4.1 cause the system not to find the base libraries like that is needed for command calls like "matlab" to start the program!
So MATLAB doesn't start!!!

Instead to reinstall Dapper or search about kernel patch I decided to wait and to try other things because in this period I don't needed Symbolic Toolbox.

Yesterday that two bloggers brought to me the solution!

I fixed the issue in this way:

download THIS FILE with the patched directly from the MathWorks site

Unpack the zip, I guess you unpacked it on your desktop if not change some path in the next rows.

From the terminal go to your MATLAB installation directory for me:
~$ cd /usr/local/matlab7
go to bin/glnx86
[install_folder]$ cd bin/glnx86
make a backup copy of libmaple:
$ sudo mv
copy the patchd in the same folder:
$ sudo cp /home/[user]/Desktop/ ./
change file's owner and group
$chown root:root
make the file executable by the owner, by the group any by any users:
$chmod ugo+x
Little explanation of chmod... I typed "ugo" because it was funny ;-) to be more strict we have had to use "ogu":
"o" means owner
"g" means group
"u" means users
"+x" means add the execution permission to the file (type "-x" to remove it)

so we added exec permission to that file either for the owner "o" either for the users in the group "g", either for the generic user "u"!
The typical order of permission is owner-group-users so "ogu" is more correct... but "ugo" is funnier!!! ;-)

To view the permission of files use ls -l instead of the optionsless ls.

Now all is fixed, this is the ultimate solution to the issue because the new library doesn't link anymore to GLIBC_2.0

I've been longer than I planned but I give some explanation on chmod too! :-P

see ya!

Useful links:

PS: obviously I was talking about my neighbour's computer with MATLAB 7 R14 lincensed installed ;-)

Friday, December 8, 2006

Beryl Tutorial end: my result

Beryl Tutorial part 3: Configuring xorg.conf

Very good, finally we come at the conclusion of this tutorial for Beryl + AIGLX setup on Ubuntu/Kubuntu Edgy!
For theATI users they don't have to do so much... after the driver setup I got Beryl work without any further xorg.conf configuration.
If you have new ATI cards (mine is old and I believe it doesn't have many of these options), you can insert these options in the "Device" section of your xorg.conf:

Option        "AGPFastWrite" "yes"
Option        "AGPMode" "4"
Option        "ColorTiling" "on"
Option        "EnablePageFlip" "true"
Option        "AccelMethod" "EXA"
Option        "XAANoOffScreenPixMaps"
Option        "RenderAccel" "true"
Option        "DRI" "true"

Now we pass to the NVIDIA users!
to me it works very well with a GeForce GFX 5700LE with these option in the "Device" section:

Option        "NvAgp" "3"
Option        "RenderAccel" "true"
Option        "AllowGLXWithComposite" "true"
Option        "DPI" "96 x 96"
Option        "AddARGBGLXVisuals" "true"

Every time you modify you X server configuration you need to restart it to be sure that it works with the new parameters set. You have to press CTRL + ALT + BACKSPACE to restar the X server.

So we are finishing... we only miss to execute beryl and emerald, watch how they work and set their configuration options as we like!

To make them start in the auto-start sequence in Gnome we only need to insert "beryl" and "emerald" calls directly in the list of the startup command by opening the utility: System -> Preferences -> Sessions.

With KDE we need to copy the next script in the folder /home/[user_id]/.kde/Autostart


let's save it as and let's make it executable modifying its permissions:

/home/[user_id]//.kde/Autostart$ sudo chmod 777

Now enjoy configuring beryl and emerald.
Their configuration utilities are easily available in Gnome under System -> Preferences named as "Beryl Settings Manager" and "Emerald Theme Manager"
from the Kmenu at the record "Settings" with the same names.

Congratulations to everyone to have completed this how-to. To the guys that succeeded in setting up Beryl and Emerald I say: "Enjoy! Linux is the best!", to those who have some trouble yet I'm available for any explanation request, complaint, correction in the how-to, so if you find mistakes in this tutorial you are invited to make me aware: we all will benefit of corrections! Linux is the best also for this: it has a very strong and vast community of users that collaborate and share their knowledge each other... Ubuntu has this same philosophy! "Ubuntu" means "I am what I am because of who we all are!" Let's continue with this spirit and we will go further and farther!

Greetings to everyone,

updated: first (and by now only) bug: Beryl on NVIDIA freezes is is started or previewed "Braid" screensaver on Gnome... check if it happen to you too, solution: don't use that screensaver... it's ugly too! ;-)

Beryl Tutorial part 2: Installing 3D drivers (Nvidia)

Now it's the time of the Nvidia guys.
I repeat these rows common to every one:

First of allcreate a backup copy fo the X server configuration file:

~$ cd /etc/X11
/etc/X11$ sudo cp xorg.conf xorg.conf.old

In this way you will be able to restore the working configuration of X at any time simply inverting the arguments of cp command:

/etc/X11$ sudo cp xorg.conf.old xorg.conf

To get work correctly an Nvidia adaptet with Beryl you have to download the latest available version of the Nvidia driver for linux directly from Nvidia site. Here I link the version that works on my desktop installation the 9629 (installation instructions - file).

While the file is downloading (it quite big) check that these packager are NOT installed :


if they were installed... uninstall them with:

apt-get remove nvidia-glx nvidia-glx-legacy

it's noticeable that can be installed only one of this package at one time so the previous command will output always a warning because one of that packager is not installed.

Install the linux kernel headers packager according to you kernel version, tipically 2.6.17-10-generic:

~$ sudo apt-get install linux-kernel-headers-2.6.17-10 linux-kernel-headers-2.6.17-10-generic

Install these packages that will be used by the Nvidia installere to compile the kernel module for your video card

~$ sudo apt-get install xserver-xorg-dev libc6

Now you got al the packages required by the Nvidia installer and you uninstalled the one that would have caused troubles.

After the download is complete go to the folder in which you saved that file, for example if you saved if on your desktop:

~$ cd /home/[user_id]/Desktop

Change the permissionsof the file rendering it readable, writable and executable:

~$ sudo chmod 777

Now open a text shell withCTRL + ALT + F1 ... or by F2 to F6. Kill the X server process typing :

~$ pkill Xorg

Now you can execute the file typing:

~$ ./

Accept the license agreement and say yes to the questions from the wizard, above all to the request to write the configuration file you made the backup file.. and the program will backup to another file xorg.conf.backup

During setup it will say something about kernel version or modules not found, it will try to check Nvidia site to download the file needed and finally it will compile them itself don't worry about there questions... at the end it will complite correctly.

As setup is finished you will have installed the last version of the Nvidia drivers.

To varify that all is set correctly restart the X sever pressing CTRL+ALT+BACKSPACE.
If something goes wrong restore the old xorg.conf after being loggedd from one of the 6 shells in text mode: CTRL+ALT+F1 or F2...till F6.

If everything works you Nvidia users are on the way to finish too!

Beryl Tutorial part 2: Installing 3D drivers (ATI)

Here we are to the second stage of Beryl's tutorial.

First of all make a backup copy of the X server configuration file:

~$ cd /etc/X11
/etc/X11$ sudo cp xorg.conf xorg.conf.old

In this way you will be able to restore the working configuration of X at any time simply inverting the arguments of cp command:

/etc/X11$ sudo cp xorg.conf.old xorg.conf

To get work correcly an ATI adapter with Beryl you are simply required NOT to use fgrlx driver.
So control that this package is installed: xserver-xorg-video-ati.

~$ sudo apt-get install xserver-xorg-video-ati

This package should be already installed on the system and you current driver should be already this:: "ati" or "radeon" instead of "fglrx".

Edit xorg.conf configuration file:

~$ cd /etc/X11
/etc/X11$ sudo nano xorg.conf

This file is divided in sections.
Control Section "Device" it will be appear like this:

Section "Device"
Identifier       "ATI Technologies, Inc. Radeon 320M (RS200 IGP)"
    Driver       "ati"
    BusID        "PCI:1:5:0"

It's important you use "ati" or "radeon" drivers NOT "fglrx".

If you find "fglrx" you will have to reconfigure the X server to change drivers used, you need to type :

~$ sudo dpkg-reconfigure xserver-xorg

At the beginning of the wizard will be prompted the avalable drivers list, select the driver to use chosing "ati" or "radeon" by enabling it with the spacebar and confirm with enter.
Go ahead in the procedure and whether possible choose always the less or the medium configuration options to have a smooth configuration without the promt of advanced parameters. If you don't know how to set some parameters simpli press enter.
The only parameters you have to set are the ones about the screen resolution, enable all the resolution supported by your monitor using the spacebar. Typically are already selected 640x480 and 800x600, enable especially 1024x768 that is the one you most probably use
If you won't enable other screen resolutions you will see all in 800x600 at most.

Recheck xorg.conf, now in section Device should be set "ati" or "radeon".

To verify that everything works restart the X server pressing CTRL+ALT+BACKSPACE.
If anything goes bad restore the old xorg.conf after be logged in using one of the 6 shell in text mode: CTRL+ALT+F1 or F2...till F6.

Good we are on the way to finish the installation.

Beryl Tutorial part 1: Getting Beryl & Emerald

Finally I find a litte spare time to begin Beryl's tutorial....
At first my vision about Linux is this: an OS to customize as we wantto get more easy and natural to use the computer according to the activities we use it for!
So I tell you that with this guide you will work on the system you will pimp it by inserting unofficial repositories or editing configuration files by your own.
Every operation doesn't require a particular knowledge about the system so don't worry about it...let's begin with the charachteristics of the two boxer onto I installed Beryl + AIGLX:

Destktop Computer: Pentium4 3.0 GHz + Nvidia GeForce FX 5700LE 256MB + Ubuntu Edgy
Laptop: il famoso KuBook: AMD AthlonXP 1400MHz + ATI Mobility Radeon 32MB + Kubuntu Edgy

Let's begin the how-to!!!
This how-to is written for Ubuntu/Kubuntu 6.10 Edgy Eft, you can try to use it with dapper but you will have to update you Xorg server to 7.1.1 verision that has AIGLX loaded by default.

Let's open a terminal... we'll need it!

Getting Beryl
Among diverse tutorials on (this is that I looked at the most) are listed many repositories, the most reliable (less times offline) is the one hosted by

Let's edit apt configuration file (/etc/apt/sources.list) by opening it with nano editor

~$ sudo nano /etc/apt/sources.list

add this row:

deb edgy main-edgy

(You can also use Synaptic of Adept to add the new repository... I'll let to you the choice :-P)

This repo needs a key to be accessed, often developers use keys not to permit download of work in progress packages by the public...
anyway this release works though it is a beta.. indeed this repo is still protected bye authentication... so: we will able to download the key that one of the developers decided to share! Again in shell:

go to your home folder with:

~$ cd

download there the GPG key and import it in apt with this command:

~$ wget -O - | sudo apt-key add -

Now you got access to beryl's repo previously added! Now we have to install the needed packages!
Uptate packets lists with:

~$ sudo apt-get update

install these packages:

~$ sudo apt-get install beryl-core beryl-plugins beryl-plugins-data emerald beryl-settings beryl-manager beryl beryl-dev emerald-themes

To be comprehensive is will write clearly the main packages and their dependences:


So we could install the only beryl, beryl-dbus and emerald-themes and the others will be downloaded after them!

Good we completed the installation, we'll proceed in the next posts!