Jochen Hayek's Blog

I continued this blog on a self-hosted WordPress blog

2014-01-03T02:03:00.001+01:00

Jochen.Hayek.name/wp/blog-en

WordPress: Categories vs Tags

2013-12-26T04:58:00.000+01:00

Packt Publishing: WordPress Multisite Administration

2013-12-26T04:25:00.001+01:00

https://www.packtpub.com/wordpress-multisite-administration/book

Wiley: WordPress

2013-12-26T04:25:00.000+01:00

http://shop.oreilly.com/product/9781118597194.do

Head First WordPress - O'Reilly Media

2013-12-26T04:24:00.000+01:00

http://shop.oreilly.com/product/9780596805340.do

WordPress: The Missing Manual - O'Reilly Media

2013-12-26T04:23:00.000+01:00

http://shop.oreilly.com/product/0636920021391.do

how to use your WordPress blog with HTTPS (SSL)

2013-12-26T03:03:00.001+01:00

http://wordpress.org/plugins/wordpress-https/

quick publishing a web page to your WordPress blog using "Press This"

2013-12-26T02:48:00.001+01:00

http://codex.wordpress.org/Press_This

AddThis also makes use of this.

problems with fink and latest Xcode on Mac OS X

2013-12-23T23:01:00.001+01:00

http://fink.9193.n7.nabble.com/Can-t-bootstrap-on-10-8-4-td43215.html

search for gcc_selected on that page!

differences between Bourne shell, Korn shell, C shell, and bash

2013-12-19T22:00:00.000+01:00

http://www.efytimes.com/e1/creativenews.asp?edid=123101 :

Always wondered what is the difference between these four shells? Here's the answer. …

just downloaded Avishai Cohen's 2001 album Unity

2013-12-19T01:49:00.002+01:00

https://en.wikipedia.org/wiki/Unity_(Avishai_Cohen_album)

Certainly: I properly paid for it. And yes, I got it from Az. I was so surprised to find it there.

I am still missing his 1991 album Devotion,
and his 2007 album "As is...Live at the Blue Note",
and his 2008 album "Sha'ot Regishot", in English: "Sensitive hours".

I think, there are all not available as MP3 (or Ogg Vorbis).

And I also edited the above wikipedia article a little.

XML Press: DITA for Practitioners Volume 1: Architecture and Technology

2013-12-18T22:00:00.001+01:00

A comprehensive guide to DITA for implementors.

http://xmlpress.net/publications/dita/practitioners-1/
http://dita4practitioners.com/ – companion website

shell code and useless use of "ls *.tar"

2013-12-18T22:00:00.000+01:00

Consider this code (I came across such Korn shell script code recently):

TARFILE=$(ls -1 /tmp/*.tar)

According to http://partmaps.org/era/unix/award.html#ls you ought to replace the ls with a glob, e.g. like this:

[[ -s /tmp/*.tar ]] && set -A tarfiles /tmp/*.tar
for TARFILE in "${tarfiles[@]}"
do
: # ...
done

Instead you may want to enquire ${#tarfiles[@]}, i.e. the number of files globbed.

Please forgive me the naming here! I was happy to take this note anyway.

"topic-oriented authoring" with "DITA" = "Darwin Information Typing Architecture"

2013-12-16T22:00:00.003+01:00

DITA for Print (A tutorial introduction to the DITA Open Toolkit FO/PDF stylesheets):

DITA for Practitioners Volume 1: "Architecture and Technology" (comprehensive guide to DITA for implementors):

http://xmlpress.net/publications/dita/practitioners-1/
http://dita4practitioners.org – "DITA for Practitioners Volume 1"'s companion website
http://dita4practitioners.com/forums
…

O'Reilly Media book: Raspberry Pi Hacks

2013-12-16T22:00:00.002+01:00

http://shop.oreilly.com/product/0636920029083.do

HACK 05: Monitor the Raspberry Pi Hardware

HACK 08: Get More USB Ports: bus powered USB hubs vs. externally powered USB hubs, backpower

HACK 20: Add Additional Memory with Swap (do not swap on SD cards and USB flash drives!)

HACK 21: Build a Cross-Compiler Toolchain; on openSuSE:

$ sudo zypper install gcc gcc-c++ bison make ncurses-devel texinfo flex gperf libtool sed subversion gmp-devel libstdc++-devel; # there is no libstdc++-static
instead of crosstool-ng-1.18.0.tar.bz2 I got crosstool-ng-1.19.0.tar.bz2
completed building crosstool-ng like this: $ sudo make install
$ mkdir /usr/local/cross-sandbox && cd /usr/local/cross-sandbox
set prefix directory to /usr/local/x-tools/${CT_TARGET}
$ env -u LD_LIBRARY_PATH ct-ng build # because it does not like LD_LIBRARY_PATH set
*** I am stuck here ***

"radio has been denied Superuser permissions" – keep getting this message after rooting my Galaxy S 2

2013-12-16T22:00:00.001+01:00

Apart from pushing the radio out of the task manager's list (i.e. killing the command), I have not found means against this yet.

a couple of books on Perl, that you can read free online

2013-12-16T22:00:00.000+01:00

http://www.perl.org/books/library.html

Most of these books you can read online completely.

"Useless Use of Cat" Award, "Useless Use of …" Award, …

2013-12-14T14:58:00.003+01:00

Rather reasonable and entertaining reading as the same time.

In the future I will certainly refer people to his page, whenever I will happen to find an opportunity.

English grammar/writing: use of "present perfect" as opposed to "past tense"

2013-12-12T22:00:00.000+01:00

… . The choice of present perfect or past tense depends on the frame of reference (period or point in time) in which the event is conceived as occurring. … . If the frame of reference extends to the present time, the present perfect is used. … . If the frame of reference is a time in the past, or a period which ended in the past, the past tense is used instead. …

The use of present perfect resp. past tense is quite different (as described above [link]), and German native speakers confuse their use in English a lot; by my experience they rather resist accepting the difference and applying them properly in English. (This is rather annoying.)

O'Reilly Media book: Raspberry Pi Cookbook

2013-12-11T22:00:00.005+01:00

http://shop.oreilly.com/product/0636920029595.do
…
$ sudo apt-get update
$ sudo apt-get upgrade
reboot afterwards
…
2.6. Connecting with a Console Lead (using a serial terminal connection and a remote login program like "cu" AKA "call unix" or kermit)
2.9. File Sharing on a Mac Network (using netatalk)
2.10. Sharing the Pi Screen on a Mac (using VNC)
3.6. Editing a File (using the nano editor)
3.15. Making a Screen Capture (using scrot)
3.16. Installing Software with apt-get
3.17. Removing Software Installed with apt-get
3.26. Listing Connected USB Devices (using lsusb)
4 Software
4.3. Installing other Browsers (chromium-browser, iceweasel (Firefox))
4.4. Using the Pi Store [link]
13.4. Displaying Messages on an Alphanumeric LCD
…

O'Reilly Media book: Getting Started with Raspberry Pi

2013-12-11T22:00:00.004+01:00

http://shop.oreilly.com/product/0636920023371.do
$ sudo raspi-config
$ cat /proc/version
$ cat /proc/cpuinfo
http://elinux.org/RPi_Hub – Raspberry Pi Wiki
http://elinux.org/RPi_VerifiedPeripherals
the Scratch programming language [wiki] – an educational programming language
the Arduino microcontroller development platform
it has general purpose input and output pins right on the board
…

on my wishlist: an LCD panel for the Raspberry Pi

2013-12-11T22:00:00.003+01:00

NFS and bad response times – did you set actimeo=0 ?

2013-12-11T22:00:00.002+01:00

You should rather not and leave the set-up with its defaults.

actimeo=0 disables file and directory attribute caching. Only use it like this, if there are very good reasons for it.

is "Raspi" the "right nickname" for the Raspberry Pi?

2013-12-11T22:00:00.001+01:00

Even en.wikipedia.org knows that name ("https://en.wikipedia.org/wiki/Raspi"), so maybe it's at least quite usual.

headless Raspberry Pi (on my desk)

2013-12-11T22:00:00.000+01:00

It's fun to see the Raspberry Pi running headless on my desk.

As described earlier, I set up my Raspi back at home with a screen (connected via HDMI/DVI), a keyboard, a mouse, and attached via eth0 (AKA LAN), later also via wlan0 (AKA wifi).

Now I would like to boot it in "headless mode". My wifi router's ESSID is different here. I start with a LAN connection. It's amazing: I runs w/o my intervention w/o screen, keyboard, and mouse. And I can connect to it with ssh through the network.

So the challenge is to add another wifi access point with its details. I found everything I needed here:

http://www.raspberrypi.org/phpBB3/viewtopic.php?f=28&t=5590

…

I create the new wpa_supplicant.conf entry (on stdout) using the wpa_passphrase command.
I add it to /etc/wpa_supplicant/wpa_supplicant.conf .
I add "auto wlan0" to /etc/network/interfaces .
After "/etc/init.d/networking restart" or a reboot (w/o a connection through eth0) everything is fine.

Before (and after) modifying configuration files I always create backup copies of them using my utility create_snapshot.sh (resp. create_snapshot.txt). Works on my Linux-s and AIX as well. Initially it was a Korn Shell script, now it's a bash script.

Now the Raspi could join my UMTS router and my NAS sitting in the "black box" below my desk (in the office at my customer's site). Well, if it sits there, it can also be connected via eth0 as well. But now being connected through wifi , it could just sit anywhere within the "realm" of my wifis. But I still enjoy this discreet white box on my desk.

Update:
Added these two lines to my ~/.ssh/config :

Host raspberrypi
User pi

That allows you to "ssh raspberrypi" instead of "ssh pi@raspberrypi".

Adding your "public key" to ~/.ssh/authorized_keys also helps logging in the "private / public keys way" instead of supplying a password.