My Nerd score!

21 April, 2010

I am nerdier than 98% of all people. Are you a nerd? Click here to take the Nerd Test, get geeky images and jokes, and write on the nerd forum!

Guess I just had to know. 🙂


Initial VPS setup

27 November, 2008

Initial VPS setup

    – Add normal user account
        – adduser <username>
        – Generate ssh keys
            – ssh-keygen
        – Add other ssh keys to ~/.ssh/authorized_keys
            – change permissions chmod go-rw authorized_keys
    – Disable root login
        – /etc/ssh/sshd_config
            – PermitRootLogin no
    – Add the bzr ppa to /etc/apt/sources.list
        – #bzr
        – deb hardy main
        – deb-src hardy main
    – In order to install the latest and greatest bzr 1.9 at the time of writing the updates repo needs to be added also.
        – deb hardy-updates main
    – Install bzr
        – mkdir vc
        – cd vc
        – bzr init-repo bzr
    – To give bzr a little more room to breath create another swapfile and activate it
        – dd if=/dev/zero of=/swapfile bs=1024 count=196608
        – mkswap /swapfile
        – swapon /swapfile
        – Add the following to the fstab file so that the swapfile will be available after a reboot
            – /swapfile       none           swap     sw                         0 0            
    – Fix the locale problem (i386)
        – apt-get install language-pack-en
    – Edit the sudoers file by adding the following line
        – <username> ALL=(ALL) ALL

Building Liquid State Machine on Centos 4 64-bit

12 November, 2008

download the lsm toolbox from here:

unpack it to your working directory

Before trying to build the lsm toolbox you need to check that you have access to the gcc4 compiler from within your working environment, you can check this by:

$gcc -v

Which should return something similar to this

Using built-in specs.

Target: x86_64-redhat-linux

Configured with: ../configure –prefix=/usr –mandir=/usr/share/man –infodir=/usr/share/info –enable-shared –enable-threads=posix –enable-checking=release –with-system-zlib –enable-__cxa_atexit –disable-libunwind-exceptions –with-gxx-include-dir=/usr/include/c++/3.4.3 –enable-libgcj-multifile –enable-languages=c,c++,java,f95 –enable-java-awt=gtk –disable-dssi –with-java-home=/usr/lib/jvm/java-1.4.2-gcj- –with-cpu=generic –host=x86_64-redhat-linux

Thread model: posix

gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)

Should you not have the gcc4 complier installed you need to install the package gcc4-4.1.2-14.EL4 and usually create a sim link in your ~/bin folder to ensure that the version 4 compiler will be picked up first.

cd ~/bin
ln -s /usr/bin/gcc4 gcc
export PATH=/home/<username>/bin:$PATH

Now that the build environment is sorted out its onto the actual process of building the lsm toolbox. So, edit the Makefile in lsm/csim/src change the default build rule to

default: version.i filepermissions csim.mexga64 install.m

The default build rule should be around line 135 in the Makefile. Depending on where matlab is installed the file paths which are hardcoded in the build file may need to be changed. In this example using the vim regular_expression to change the path from /usr/local/matlab to /opt/matlab/ins


Now move to the csim directory and run the make command as normal.

Should an error similiar to the quote below occur,

Invalid MEX-file ‘/home/<username>/<working directory>/lsm/csim/csim.mexa64′: /opt/matlab_sp3_64/ins/bin/glnxa64/../../sys/os/glnxa64/ version `GCC_4.2.0’ not found (required by /usr/lib64/

The solution to seems to be to move the file out of the way so that matlab will use the system one first. The file can be moved via the normal unix command ‘mv’ as shown below.


Book Meme

11 November, 2008

Jumping on the meme train:

“HeadFirst: Does that mean you can refer to only one dog” Head First Java

  1. Grab the nearest book.
  2. Open it to page 56.
  3. Find the fifth sentence.
  4. Post the text of the sentence in your journal along with these instructions.
  5. Don’t dig for your favourite book, the cool book, or the intellectual one: pick the CLOSEST.

Building bzr on RHEL AS 4

13 September, 2008

In order to use the bzr distributed version control system on Redhat Enterprise Linux 4 (RHEL) you first have to build python 2.4+ (and some additional modules) as RHEL shipped with 2.3.* of python which isn’t supported by bzr. In this article I will be building python 2.4.5 and the addional modules required for bzr 1.6.1 into a folder in my home directory so as not upset any of the applications that rely on the RHEL supported version of python. So lets get started;

First get python 2.4.5 using wget as the downloader

patrickd tmp $ wget -c

Now lets use tar to decompress it.

patrickd tmp $ tar xfjv Python-2.4.5.tar.bz2

[  …………….  ]

Enter the directory that tar just decompressed it to and configure it, so that it will be installed into the directory ‘/home/patrickd/apps/python’

patrickd Python-2.4.5 $ cd Python-2.4.5

patrickd Python-2.4.5 $ ./configure –prefix=/home/patrickd/apps/python

checking MACHDEP… linux2
checking for –without-gcc… no

[ ……… ]

creating Setup
creating Setup.local
creating Makefile

Once, python is configured. It is time to build it using the ‘make’ command, then create the directory that we intend to install python to and then finally install python into the preconfigured directory.

patrickd Python-2.4.5 $ mkdir -p /home/patrickd/apps/python

patrickd Python-2.4.5 $ make

[  ……  ]

patrickd Python-2.4.5 $ make install

[ ……  ]

After python has been installed, it now time to setup some environment variables. That will enable the new 2.4 version of python to be used as the default python rather than the redhat compilied version of python.

patrickd Python-2.4.5 $ export PATH=$HOME/apps/python/bin:$PATH

patrickd Python-2.4.5 $ export PYTHONPATH=/home/patrickd/apps/python/lib/python;

Check to make sure that the environment variables are correctly set by calling python and checking the version number.

patrickd Python-2.4.5 $ python -V
Python 2.4.5

Now we need to get some additional python modules that are used by bzr.

patrickd tmp $ wget

patrickd tmp $ wget

patrickd tmp $ wget

As before decompress them,

patrickd tmp $ tar xfzv Pyrex-

patrickd tmp $ tar xfzv cElementTree-1.0.5-20051216.tar.gz

patrickd tmp $ tar xfzv paramiko-1.7.4.tar.gz

Now build and install each of them in turn.

patrickd tmp $ cd Pyrex-

patrickd Pyrex- $ python install

patrickd Pyrex- $ cd ..

patrickd tmp $ cd cElementTree-1.0.5-20051216/

patrickd cElementTree-1.0.5-20051216 $ python install

[ ………… ]

patrickd cElementTree-1.0.5-20051216 $ cd ..

patrickd tmp $ cd paramiko-1.7.4/

patrickd paramiko-1.7.4 $ python install

[ ……… ]

patrickd paramiko-1.7.4 $ cd ..

Finally its time to get the bzr source code and install it into the new 2.4.5 python installation.

patrickd tmp $ wget

patrickd tmp $ tar xfzv bzr-1.6.1.tar.gz

patrickd tmp $ cd bzr-1.6.1

patrickd bzr-1.6.1 $ python install –home /home/patrickd/apps/python/

patrickd bzr-1.6.1 $ cd ~

After building and installing bzr its now time to check that bzr is correctly installed.

patrickd ~ $ bzr version
Bazaar (bzr) 1.6.1
Python interpreter: /home/patrickd/apps/python/bin/python 2.4.5
Python standard library: /home/patrickd/apps/python/lib/python2.4
bzrlib: /home/patrickd/apps/python/lib/python/bzrlib
Bazaar configuration: /home/patrickd/.bazaar
Bazaar log file: /home/patrickd/.bzr.log

Copyright 2005, 2006, 2007, 2008 Canonical Ltd.

bzr comes with ABSOLUTELY NO WARRANTY.  bzr is free software, and
you may use, modify and redistribute it under the terms of the GNU
General Public License version 2 or later.

Now that you have finished installing bzr, I would suggest your next point of call should be bzr user guide and then the main bzr documentation page.

Booting problem after upgrading to ubuntu hardy (8.04)

28 May, 2008

I’ve been running 8.04 beta for a while now, with kernel 2.6.22-14 the system boots and runs just fine. However, with the recent updates to the kernel 2.6.24-15 and then to 2.6.24-16 the system fails to boot and “hangs” at the “loading” screen with the blue progress bar just moving back and forward. In the trimmed menu.lst only the last option boots.

patrickd@ubuntu:/media$ lsb_release -rd
Description: Ubuntu 8.04
Release: 8.04

title Ubuntu 8.04, kernel 2.6.24-16-generic
root (hd0,5)
kernel /boot/vmlinuz-2.6.24-16-generic root=UUID=761e8f2c-dd8d-4042-a5bb-2ead0c26c54e ro quiet splash
initrd /boot/initrd.img-2.6.24-16-generic

title Ubuntu 8.04, kernel 2.6.24-15-generic
root (hd0,5)
kernel /boot/vmlinuz-2.6.24-15-generic root=UUID=761e8f2c-dd8d-4042-a5bb-2ead0c26c54e ro quiet splash
initrd /boot/initrd.img-2.6.24-15-generic

title Ubuntu 8.04, kernel 2.6.22-14-generic
root (hd0,5)
kernel /boot/vmlinuz-2.6.22-14-generic root=UUID=761e8f2c-dd8d-4042-a5bb-2ead0c26c54e ro quiet splash
initrd /boot/initrd.img-2.6.22-14-generic

After some back and forth with the ubuntu developers it using this bug report on launchpad, It appeared that the newer versions of the kernel where unable to mount my root partition. Then after some digging about in one of my old note books I discovered that I’d come across the same problem with another distro and at the time the solution was to add “pci=nomsi” to the kernel boot options and thankfully that seemed to have solved the problem this time to.

This workaround enabled my system to boot with the ubuntu 2.4.26-16-generic kernel.

patrickd@ubuntu:~$ uname -a
Linux ubuntu 2.6.24-16-generic #1 SMP Thu Apr 10 13:23:42 UTC 2008 i686 GNU/Linux

The workaround for me was to add “pci=nomsi” to the kernel boot options, so the entry in fstab now looks like;

kernel /boot/vmlinuz-2.6.24-16-generic root=UUID=761e8f2c-dd8d-4042-a5bb-2ead0c26c54e ro quiet pci=nomsi splash

Pingus and Pulseaudio on Hardy

30 April, 2008

After installing pingus on ubuntu hardy (8.04) I discovered that the sound only worked when no other applications where using the sound card, which is a bit of a pain. When trying to start pingus from a gnome terminal the following message appeared;

patrickd@battlestar:~$ pingus
Welcome to Pingus 0.7.2!
data path: /usr/games/../share/games/pingus/data/
language: English (en)
font encoding: iso-8859-1
sound support: enabled
music support: enabled
resolution: 800×600
fullscreen: disabled

Unable to initialize SDL_Mixer: No available audio device
Pingus: Unknown throw caught!

The interesting thing about this error is that it doesn’t appear to be pingus specific instead a generic SDL type problem. So, once again after some googling the solution that I came up with is shown below, I had tried a couple of other ones like “$ padsp pingus”, padsp appears to be a wrapper for pulseaudio (which is the default backend for hardy) and “export SDL_AUDIODRIVER=esd et” but this didn’t work either. I even found a post which suggested using “export SDL_AUDIODRIVER=pulse” but again this didn’t work for me. In the end I installed the pulseaudio “driver” for libsdl kind of obvious when you think about it 🙂 ;

patrickd@battlestar:~$ apt-cache search libsdl | grep sdl
libsdl-image1.2 – image loading library for Simple DirectMedia Layer 1.2
libsdl-image1.2-dev – development files for SDL 1.2 image loading libray
libsdl-mixer1.2 – mixer library for Simple DirectMedia Layer 1.2
libsdl-mixer1.2-dev – development files for SDL1.2 mixer library
libsdl-pango-dev – text rendering with Pango in SDL applications (development)
libsdl-pango1 – text rendering with Pango in SDL applications (shared library)
libsdl-ttf2.0-0 – ttf library for Simple DirectMedia Layer with FreeType 2 support
libsdl-ttf2.0-dev – development files for SDL ttf library (version 2.0)
libsdl1.2-dev – Simple DirectMedia Layer development files
libsdl1.2debian – Simple DirectMedia Layer
libsdl1.2debian-all – Simple DirectMedia Layer (with all available options)
libsdl1.2debian-alsa – Simple DirectMedia Layer (with X11 and ALSA options)
libsdl1.2debian-esd – Simple DirectMedia Layer (with X11 and esound options)
libsdl1.2debian-oss – Simple DirectMedia Layer (with X11 and OSS options)
libsdl-console – console that can be added to any SDL application
libsdl-console-dev – development files for libsdl-console
libsdl-erlang – Erlang bindings to the Simple Direct Media Library
libsdl-gfx1.2-4 – drawing and graphical effects extension for SDL
libsdl-gfx1.2-dev – development files for SDL_gfx
libsdl-net1.2 – network library for Simple DirectMedia Layer
libsdl-net1.2-dev – Development files for SDL network library
libsdl-ocaml – OCaml bindings for SDL – runtime files
libsdl-ocaml-dev – OCaml bindings for SDL – development files
libsdl-perl – SDL bindings for the Perl language
libsdl-ruby1.8 – Ruby/SDL interface for Ruby
libsdl-sge – extension of graphic functions for the SDL multimedia library
libsdl-sge-dev – development files for libsdl-sge
libsdl-sound1.2 – Decoder of several sound file formats for SDL
libsdl-sound1.2-dev – Development files for SDL_sound
libsdl-stretch-0-2 – stretch functions for Simple DirectMedia Layer
libsdl-stretch-dev – development files for SDL_stretch library
libsdl1.2debian-arts – Simple DirectMedia Layer (with X11 and aRts options)
libsdl1.2debian-nas – Simple DirectMedia Layer (with X11 and NAS options)
libsdl1.2debian-pulseaudio – Simple DirectMedia Layer (with X11 and PulseAudio options)

patrickd@battlestar:~$ sudo apt-get install libsdl1.2debian-pulseaudio

Now I can happily run amarok and pingus 🙂 I suspect this will probably work for other SDL based games like frozen-bubble.