Vorstellungsgespräch für Lehramt beruflische Schulen

Heute hatte ich mein Vorstellungsgespräche für den Quereinstieg ins Lehramt. Die Fragen waren fair. Zum einen zielten sie darauf ob ich mir über den Zeitaufwand im Klaren sei. Dann wie ich mir den Umgang mit Schülern vorstelle. Durch meine Ausbildung bei der Bundeswehr gab es wohl die Befürchtung das ich zu sehr auf Hierarchie bauen würde, ich glaube aber das konnte ich gut entkräften.

Dann gab es noch Fragen in Bezug auf die Veränderung in der beruflichen Ausbildung. Ob ich mir was unter dem Wort “handlungsorientiert” vorstellen könne. Ob die Schule mehr auf die Prüfung vorbereiten soll oder allgemein Kompetenz zum erlangen von Wissen vermitteln soll.

Ich glaube im großen und ganzen ist es sehr gut gelaufen. Bin mal gespannt wann ich was vom Ergebnis höre. Könnte noch bis Ende Oktober dauern.

Das Studienseminar erscheint als ein Ort von einer anderen Zeit. Auf der Toilette ein Aufkleber der zur Demo gegen den Opernball aufruft. Allgemein habe ich das Gefühl da herrscht noch ein Klima des freien Geistes. Ich glaube die zwei Jahre können ein sehr schöne, aber auch harte Zeit werden. Im Flur hängen Bilder von den Abschlussklassen. Ich bin begeistert über was ich da gesehen habe. Von einem ehemaligen Referendar habe ich schon gehört wie gut der Zusammenhalt war und das sie sich immer noch treffen. So hoffe ich das ich auch in so eine Gruppe kommen kann.

Xen-Virtualisierung und Zeit

Seit einiger Zeit hatte ich das Problem die Zeit auf einer Xen-virtualisierten Maschine zu verändern. Alle Versuche scheiterten, bis ich die Zeit auf dem Wirtsystem dom0 änderte und siehe da, die Gastmaschinen hatte auch alle die korrekte Zeit.

Eine Suche bei Google brachte mich dann auch zu einem Xen FAQ.
In dem FAQ wird beschrieben das unter Xen standardmäßig die Zeit der Gastmaschinen an die Wirtmaschine dom0 gekoppelt ist.

perl: warning: Setting locale failed. 2nd

>perl: warning: Setting locale failed. 2nd

My previous post was an overkill. Simple solution is to run:

locale-gen en_US.UTF-8

perl: warning: Setting locale failed

>perl: warning: Setting locale failed.

I am getting this error message when calling perl:

perl: warning: Setting locale failed.

perl: warning: Please check that your locale settings:

LANGUAGE = (unset),

LC_ALL = (unset),

LANG = “en_US.UTF-8″

are supported and installed on your system.

perl: warning: Falling back to the standard locale (“C”)

I found a bunch of posts to call:

# dpkg-reconfigure locales

But I only got a the reply:

# /usr/sbin/dpkg-reconfigure: locales is not installed

So I installed the package language-env and running dpkg-reconfigure again worked this time.

However, I believe this is an overkill for a server. I thought there was a simpler method to solve that, by just re-installing an already installed package, but I don’t recall now which one that was.

>How to allow an user access to /dev/ttyUSB0 on Linux?

>Allowing access to /dev/ttyUSB0

OK, here are my steps to get access to the /dev/ttyUSB0.
I have a file ‘test.txt’ that contains the characters ‘abcd’

>cat test.txt

abcd

Now I try to send that string to the ttyUSB0 device:

>cat test.txt > /dev/ttyUSB0

bash: /dev/ttyUSB0: Permission denied

Just make sure that the device is there:

>l /dev/ttyUSB0

crw-rw—- 1 root uucp 188, 0 2008-09-26 17:13 /dev/ttyUSB0

Let’s check what classes I am allowed to access:

>/sbin/resmgr classes

desktop

dvb

v4l

sound

video

input

cdrom

floppy

usb

camera

scanner

pda

audioplayer

For accessing serial devices I want to add the ‘modem’ calls to my access rights. So in the folder /etc/resmgr.conf.d I create a new file 50-modem.conf with the rule:

allow modem user=linux

‘linux’ is my user name. Now I need to restart the resmgrd daemon in order for the rules to be loaded again.

>sudo /etc/init.d/resmgr restart

Shutting down resource manager done

Starting resource manager done

Let’s check that I am assigned to the ‘modem’ class now:

>/sbin/resmgr classes

modem

desktop

dvb

v4l

sound

video

input

cdrom

floppy

usb

camera

scanner

pda

audioplayer

And yes, there it is, right at the first place. Now I need to replug the USB device in order for the rule to get applied to it.

>l /dev/ttyUSB0

crw-rw—-+ 1 root uucp 188, 0 2008-09-26 17:23 /dev/ttyUSB0

Device is there and now try to send the data again:

>cat test.txt > /dev/ttyUSB0

>

No error message, that means the data go send without any problems.

>Should I add users to the group uucp?

>That was my question to access a /dev/ttyUSB0 device under openSUSE Linux. Over the opensuse-security mailing list I got a link to a document about the Resource Manager in which this question gets answered.

Basically, the Resource Manager is responsible to grant users access and it also handles the access to hardware. No need to add a user to an additional group or change udev-rules in order to get access to hardware.

replace ^M with vim

>replace ^M with vim

I never seem to remember that in vim you need to press CTRL-V CTRL-M in order to get the ^M character.

I always end up looking for this VIM TIP to tell me.

Understanding hg pull and hg update

>Understanding hg pull and hg update

Coming from a CVS/Subversion background I was confused about the use of hg pull and hg update in connection with Mercurial.

The core differences between CVS/Subversion and Mercurial is that with the later, repository and working copy are together. The repository is in a .hg folder and the working copy are the files and folders around that.

That means when doing a hg pull, only the repository is affected. To have the working copy, that means the files and folders around .hg to be updated with that change, it requires a hg update.

That is fairly similar to Subversion for example, but there the repository was somewhere else and you knew that the update went to the repository to get the updates. Actually the same with Mercurial, just that here the connected repository is inside the project folder under the .hg folder.

Say goodbye to Numeric; or how to replace Numeric by NumPy

>Say goodbye to Numeric; or how to replace Numeric by NumPy in a bigger project

Having a larger Python project that relied on Numeric I was looking for a simple way to replace all Numeric imports by NumPy.

My first goal was to figure out how many files where affected by that change and I did a

grep -rn –include=*.py ‘Numeric’ *| gview -

That piped the output to gview. Got the information that there are over 20 files affected I was looking for a way to open them all in gvim.

The command that helped was:

gvim `grep -rl –include=*.py ‘Numeric’ *`

Now went on with:

:bufdo %s/from Numeric/from numpy/ge | update

After that went through the files again and searched for ‘import Numeric’ to replace them by ‘import numpy’.

gcc and Warnings

>gcc and Warnings

The gcc compiler enables the print out of warnings with the -W option. One way to print a lot of warnings is with the -Wall option. This suggests that it will enable all warning messages that are possible, however, reading in the gcc online manual the section Options to Request or Suppress Warnings shows that not all warnings are enabled.

One extra option that enables a whole bunch of warnings is the -Wextra option.

I need to assemble a list of useful warnings. I noticed when moving code from gcc to Visual C++ I am getting much more warnings. Not that they all are meaningful, but exactly that is what I should assemble, a list of useful warnings that improve the code.