18 Oct 2007

Another day, another cable

Another day, another cable

This article provides some interesting incites to why we pay so much for so little in South Africa when it come to the internet.

2 Oct 2007

vlc segmentation fault

I recently had problems with vlc media player. It would crash unexpectedly when running. It would not start when run from the Applications > Sound & Video > VLC. Occasionally it would start up but it would look terrible, or start two player interfaces. I then turned to the console using vlc, or wxvlc to get it to run. Some times it would come out with two player interface's, and whole string of exceptions.

Solution

in your home directory /home/yourhome/ their is a config directory for vlc called .vlc /home/yourhome/.vlc go and delete it completely. VLC automatically creates it when it is frist started. This will reset all the settings that could cause this type of problem.
rm /home/[you home dir]/.vlc

Immediately after doing that I tryied vlc from the application menu and it worked. I expect that I am not the only one to have this problem. I hope it helps some one else out there.

25 Sept 2007

Bauer-Power: Information is Power!

Bauer-Power: Information is Power!

A really good video on how data recovery works. It was associated with 2 links to sites that have more info. http://myharddrivedied.com/presentations.html and web.forensicspeak.com. If any one is interested in finding out more about recovering data on a hard drive I recommend these sites. If you are interested in taking apart a hard drive go to the video above.

I also recomend going to http://www.cgsecurity.org/ it explains to linux tools for data recovery. I have used the one and it worked for me. I was able to recover from bad partion information. It has a number of links as well to site that could prove to be useful.

15 Sept 2007

Coding Horror: Gigabyte: Decimal vs. Binary

Coding Horror: Gigabyte: Decimal vs. Binary

This is an in depth look at why a 250 gb hard drive is a lot less then the advertised size.

8 Sept 2007

Apache2 Documentation apache2-doc manuall problems

For those of us who want to find out how to fix the problem of apache2-doc at http://localhost/manual/ giving us junk like this

URI: index.html.de Content-Language: de Content-type: text/html; charset=ISO-8859-1 URI: index.html.en Content-Language: en Content-type: text/html; charset=ISO-8859-1 URI: index.html.es Content-Language: es Content-type: text/html; charset=ISO-8859-1 URI: index.html.fr Content-Language: fr Content-type: text/html; charset=ISO-8859-1 URI: index.html.ja.euc-jp Content-Language: ja Content-type: text/html; charset=EUC-JP URI: index.html.ko.euc-kr Content-Language: ko Content-type: text/html; charset=EUC-KR URI: index.html.pt-br Content-Language: pt-br Content-type: text/html; charset=ISO-8859-1.

Which is a type map, which is meant to allow for multiple languages in the documentation. It dose not work so to fix it try the following at this link.Apache2 Documentation doesn't work - Ubuntu Forums.

I changed these instructions a bit by
sudo mkdir typemaps
and
sudo mv *.html to ./typemaps/
which moved the all the *.html type map pages to the typemaps dir. so if I need to restore them I can. you could also just delete them with
sudo rm -f *.html
but then you have no way of retrieving them. This post dose not contain any documentation on modifying the /etc/apache2/apache2.conf file.

You may have to repeat the above instructions in some of the /usr/share/doc/apache2-doc/manual/ sub directories, like: developer, faq, howto, misc, mod, rewrites, programs, platform, ssl, and vhosts. As the documentation links to them as well.

3 Aug 2007

Away From Home, by Ame Haji Ame's

This is a poem written by one of the students I tutored last semester. I think It is worth posting on my blog.

Away from home in a strange land.
Young people don't greet "Mambo?".
You don't greet strangers in this land.
No anymore "Salaam Alaykum" to everyone.
Here people judge you with your colour,
They don't judge you with your hair and finger nails.
No combing your hair is fashion in this land!
You can't walk alone as you do in Stone-Town streets.
The food is labelled 'Halal' for Muslims.
Drinking alcohol is not a sin but big business
Females smoke more than males in this strange land!

In this land, fish is more expensive than beef.
This land is not English, but they grow English tomatoes.
Here dates are more expensive than apples!
Spices are thirty times expensive in this land.

But good things are here:
People don't walk kilometres for water.
There is no power rationing in this land.
Houses have heaters and not coolers in this land

But money kills people each and everyday.
Innocent people die, criminals live in total happiness!
Crime rate is higher than inflation rate in this land!
Cars are the best transport than bicycles on this land.
Birds don't sing but shout on this strange land!
Cameras are everywhere, privacy is nowhere in this land.
Marriages are no more for the opposite, but for the same sex.
People care for things and not beings on this land.

This land is so strange, making you think of home always.
This land is strange, and has more strangers.
This is a land of fear, and is a land of dreams.

My land is the land of peace,
The land of spices, and not pieces.
My land is the land of people and not things.
My land is the only haven under the sun.

by Ame (A-Zu)

19 Jul 2007

A good resource on how 2 on configure feisty

This site http://ubuntuguide.org/wiki/Ubuntu:Feisty has a complete how to guide on every thing you would want to configure in Ubuntu. It is defiantly worth a look at.

27 Jun 2007

Contacts, Calandar back up on online server

For a while now I have been looking for a way to sync my contacts, on my laptop and cell phone as well as my calendar. Scheduleworld.com provides a free way to do that.

It is compatible with Google's gmail, and gcal. So it provides an all in one solution. It also works with evolution mail client in Linux with a special plugin you can download.

All the information is on their web site. Check out these links to find out more.
http://www.estamos.de/projects/SyncML/Support.html
http://ubuntuforums.org/showthread.php?t=282408
http://www.scheduleworld.com/tg/syncmlInfo.jsp.

7 Jun 2007

nvidia restricted binary drivers and settings

I have found a really nice tool for setting up the xorg.conf and daul view. From the command line in Ubuntu type gksudo nvidia-settings. Up pops nvidias GUI tool for setting up your nvidia card and xorg.config.

Only it has problems, or at least I had problems. they relate to where some of the advanced nvidia settings are stored in a file called .nvidia-settings-rc. From your home directory type ls -a .nvidia-settings-rc. This file is basically used to initialize your graphics card at boot and is linked into the boot process through the init folder in /etc/rcX.d.

The problem I had with this file was that the permissions on it doesn't allow the program to rw access it and execute it. I may be wrong here. What I did to fix the problem was change the permissions from
user@user-machine:~$ ls -l .nvidia-settings-rc
-rw-r--r-- 1 user user 1511 2007-06-06 18:33 .nvidia-settings-rc
to
user@user-machine:~$ ls -l .nvidia-settings-rc
-rwxr-xr-x 1 aaron aaron 1511 2007-06-06 18:33 .nvidia-settings-rc
with a chmod 755 .nvidia-settings-rc. now it probably dose not need the execute permissions some thing to experiment with but make sure it has the rw.
basically try:
$ chmod u=rw,g=rw,o=rw .nvidia-settings-rc
$ gksudo nvidia-settings.

I still get a lot of ERROR .... (no Display connection) messages on the command line but at least now it actually generates the xorg.conf file in the /etc/X11/ directory.

I'm not sure what the error messages mean or how to fix it. It has some thing to do with the advanced options of gamma, colour saturation. This can be fixed but I didn't find it necessary to. There is some discussion at the nvidia forums. Check out this thread http://www.nvnews.net/vbulletin/showthread.php?t=61396 it seams to have the most though discussion on fixing it.

Please post you comment on this if you have any solutions for the ERROR ... (no Display connection) problem.

Ubuntu 7.04 Feisty Fawn

I am a real distro whore and have moved to yet another one. My favorite so far Ubuntu has always been on the top of the list of distros I wanted but with telkoms internet connection prices I have always chosen distros with more software then comes on the Ubuntu free cd.

I have used fedora 4, 5, and 6. I think that fedora gets a lot of free publicity because of Red Hat. It is no way near to the functionality and ease of use in the GUI that can be found in either suse or Ubuntu. I think any one who uses fedora just cause of it's relation to Red Hat should consider moving to suse or Ubuntu. I have only used these distros for desktop productivity, programing and web development. So as far as running a server is concerned I can't cant say which one is better.

I have used suse 9.2, 10, 10.1 and finally moved over to a complete Linux system one my acer travelmate 5623 with 10.2. I have to say that suse with yast make Life very easy. The GUI based install can be done buy any one and it is rpm based so all the red hat packages tend to be compatible. I have found it to be a little slow, and it has crashed on me relating to X windows problems. I have used the 3D desktop across two screens on suse with out much problems, although I prefer to use it with out desktop effects as it works better because Lap top and 19" dont have the same resolutions. Over all I am very happy with novels suse product. In terms of usability I have to say it is one of the easiest I have used.

I have installed Debian on an old Pentium 1 I had lying around. It was a pain, never got X to work so I never used the Gui. It was a pain to install, but then they aren't aim at making it easy to use they are aiming at making it stable so if X cant figure out what settings it is meant to have then it is doing what it was created to do be stable.

Now I have moved completely to Ubuntu. I was able to get a friend to download the dvd of 7.04 and this has so far been what I am looking for. I have struggled with X. Similar problems to that of Debian, the auto config is that automatic and requires some expert knowledge on how to set it up. But in general after googleing a bit I found the solutions I needed. For X and some other commonly tried advanced configurations such as visualization go to librenix. I also found that nvidia has made a graphical tool called nvidia-settings to solve most problems I will put my solution in a new post to make it easy to Google.

Ubuntu is faster then suse probably cause their generic kernel is using more i686 code and take better advantage of my SMP (symmetric muilt-processors, dual core). I have been playing with beryl and it is definitely hands down the best desktop effects product out there. More settings better features every thing is better. I still need to do some development on Ubuntu to get a better feel for it but so far it is exactly what I am looking for a LAMP system.

I understand them not including Java, adobe, and some other free but proprietary licensed software but once every thing is up and running all you need to do is enable the relevant repos through synaptic and you can easily download them. Synaptic comes close to yasts in that it allows you to add cd and dvd repos which make life a breeze. Synaptic though is not an all in one control panel like tool which is what yast is. I will stick with the way Ubuntu is laid out for the moment, though I might try to install yast a little later.

2 Jun 2007

xorg and xserver issues in Linux ubuntu

Dual monitor support in Linux seam lacking, so do tools to configure them. May be I not looking hard enough. I would have expected xorg to have written some nice GUI tools to configure the product.

Having to edit the xorg.config text file seams like a real waste of time, and is very confusing for new linux users. Do a search on google for xorg prolems and xserver problems there are just to many. Most come down the the automatic detection program / scripts not working. I dont have a problem with this cause there is just so much hard ware out their.

My suggestion for the the guys at xorg or who ever to create a nice gui front end for the xorg.config file with human understandable instructions on how to create a working conifg file. I will have a look into this my self when I have time. but in the mean time as I have now moved to ubuntu 7.04.

This link will suffice to help those wanting to create set up thier monitors for a dual view system http://ubuntuforums.org/showthread.php?t=221174.
This one is for just after install isues https://help.ubuntu.com/community/FixVideoResolutionHowto.
Like if you get the famous xserver failed to start error after a new install or you have screen resolution problems.

Free online and downloadable books

I am going to start of list of links for finding good free books to view on line or to down load. I will have a similar list as I have on the right hand side for ftp sites.

Good list of linux and open source materails as well as others. http://eo.yifan.net/users/k/aravind/olbooks.htm

28 May 2007

Nesting the SQL COUNT() function in MAX(COUNT())

EXPERT RESPONSE FROM: Rudy Limeback

QUESTION POSED ON: 23 June 2006

I am trying to run this query and I get an error:

SQL> select
2 * from member m
3 where m.username IN (select fg.username from filmography fg,
4 (select f.username,max(count(awards)) from filmography f
5 group by username,awards
6 having max(count(awards))
7 >0));
having max(count(awards))
*
ERROR at line 6:
ORA-00935: group function is nested too deeply

Please help me.

EXPERT RESPONSE

Okay, the error message is saying that you cannot nest functions like that.

It looks like all you want is the member with the most awards. Here's how I would do this in Oracle:

select username
, othercolumns
from member
where username in
( select username
from ( select username
from filmography
group
by username
order
by count(awards) desc
) as t
where rownum = 1
)

WHERE ROWNUM=1 is used to obtain the row which has the largest COUNT(AWARDS) in the innermost subquery.

I have seen many people struggled with this type of question at university now I have found a solution that works.

10 May 2007

New ftp / mirror site every one should have a look at

I just found this site while looking for local South African resources for open source distro's, and other open source product. This has to be one of the best sites that I have found ever. It has mirrors for Ubuntu, fedora, bsd, gentoo and a whole lot more. TENET Tertiary Education Network http://mirror.ac.za/

One of the best parts of this site is the local link to the MIT open course ware site. http://ocw.mirror.ac.za/. A brilliant place to read up on just about any thing from rocket science to management and psychology.
I will definitely be using this site a lot in the future.

here is a list of the links available
Mirror Description:
MIT Open Courseware
Course materials for a wide range of topics
PHP.NET Mirror
PHP is a server side scripting language for web devlopment
ProFTPD Mirror
Is a GNU open source mirror of the Pro FTP project which is ftp server software.
Mozilla Mirror
Blastwave Solaris FreewareMirror
GENTOO Linux Mirror
FreeBSD Mirror
Knoppix Linux
Ubuntu Mirror
Centos Mirror
Debian Mirror
Slackware Mirror
bio-mirror.net Mirror
Is a mirror of a database containing genetics research
OpenOffice Mirror
MySQL Mirror
CPAN Mirror
Comprehensive Perl archive network is a major resource for Perl programmers.
Fedora MirrorCTAN Mirror
Is a TEX mirror, TEX is a language / tool set for formating and structuring text for publishing web development and so on,
www.honeynet.org Mirror
Is a site focused on network security, they have a large library of network security related information.
Scientific Linux Mirror

9 May 2007

how to load a file in xspim

I am tutoring a class that teaches basic assembler using the mips architecture and spim. Im using linux so i got the source and compiled and installed it. I then began buy running xspim. What a pain no documentation enplaning any thing that I could make sense of. So here I am writing about how I got it to work.

This is how to load an assembler file and make sense of the first screen you see when you first run xspim.
start xspim buy typeing
#> xspim
at the comand line. or buy running it from the /usr/local/bin/xspim
#> /usr/local/bin/xspim
depending on your configuration.

The following window pops up.

The assembler you can see in the text segment part of the window doesn't run and out puts an error sayin
Instruction references undefined symbol at 0x00400014
jal 0x00000000 [main].
This code that is already loaded comes from the /usr/local/lib/exceptions.s file. It is the assembler code to load and run your file.

You can load your file buy clicking the load button in the middle part of the window. This is will open the following pop window.Input the file location relative to the root (/) directory ie as /home/#user/mips/my_file

click the assembly file button. You will see that the jal xxxxxxxx [main] command changes to reference your code at memory location xxxxxxxxx. which will be just after the load program code.
the jal xxxxxxxx [main] instruction is a jump and load instruction with the memory address and label [main] being the label. So you need to have a lable in your source code that contains a main label.
my_file looks like this
.text
main: addi $v0, $0, 5 # read into $t1
syscall
add $t1, $0, $v0
addi $t1, $t1, -32 # F -32
addi $t2, $0, 5
mult $t1, $t2 # (F -32) * 5 (mult before div)
mflo $t1
addi $t2, $0, 9
div $t1, $t2 # (F -32) * 5/9
mflo $t1
addi $v0, $0, 1 # print $t1
add $a0, $0, $t1
syscall
addi $v0, $0, 10 # exit
syscall

what's important here is th "main:" part of the code which will be where the jal xxxxxxxx [main] will jump to when running your assembler. Now you can step through your code and run it buy clicking the relevant buttons. You will notice that their args parameter references your mips file. You will need to edit your mips assembler file with an other program like gedit, or scite.

It took me a while to figure out how all this worked as the documentation dose not have a quick start tutorial or any thing like that. I hope this will be use full for some assembler hackers out there.

15 Apr 2007

New kernel for suse 10.2

I recently upgraded my suse kernel to suse to the one available in the update source that yast automatically adds. It fixed among other things the spdif out that my head phones jack into. Previously it didn't work although sound did and it played through the speaker built into my laptop.

It seams to be more responsive as well in gnome. If their are any other big changes I notice I will post about them as well.

Web standard & Web Scripting

I have just found one of the best resources on web site development. It is mostly focused on clinent side scripting and has some of the best HTML, CSS and javascript tutorials I ever read in all the tutorials I have come across.

howtocreate.co.uk

If you want to understand cross browser compatibility or more precisely Microsoft and IEs standards incompatiblity. He has one of the most though articles describing Microsoft incompetent and deliberate no use of standards in rendering web content. This is one more reason to try an open source or other browser that dose. Like firefox or opera.

8 Apr 2007

tut week 5

Tut 5 for week five was on uml, not the most exciting tut. Im using a free open source uml molder in Linux.
opensuse 10.2 comes with umbrello. It has every thing you could think of for uml modeling. Well I know that I will do a lot of this in my assignment.

I didn't like the one tut question in which we had to try and recreate a uml diagram out of our text books. That seamed to basic for me but over all the tut was ok.

27 Mar 2007

Tut 4 week 4

Last weeks tut number 4 was for fit2001 was not very interesting, we used the time to ask questions in a group about the assignment. I think the assignment will be quite interesting. We spent quite a bit of time discussing it in the Group.

The session we had with the Lecture was quite quick it was only about 15 min. I sure we got all the info we need for the assignment.

tut 3

I have not posted in while, tut 3 was a bit of a let down. We were supposed to listen to a pod cast with the creator of Basecamp, Jason Fried. It did not happen till after the tut. This is because the internet connection at Monash is controlled buy telkom (read below).

I went to the web site for base camp and did some wikipedia research on the topic. I think its quite an interesting product which was developed in a non traditional way. Similar to Many of the Google things which is release a beta, and keep in a beta state while the users interact with it and give feed back. They call this a gamma sate. It is rapid user centered development. As a good idea gets out their on the web and then the users get to decide how it looks and works.

Its interesting to see that their are other way of doing the same things, and with the internet we have not explored all of them.

1 Mar 2007

Operating Systems and A new computer

I recently got an new Acer travelmate 5623, as my previous HP nx9110 stoped working. According to HP it stoped working because of mother board ware and tear. Which would cost R 5000 to replace.

My new Acer came with vista as it was a R 1000 cheaper to go with vista over XP. Apparently Acer is not shipping their products with system disks. So I had to use my DVD writer to create an image of my system for back and install purposes. Good thing to, with in 2 days I had to reinstall vista to get around an annoying error message that kept coming up. It had to to with user profiles and the folders linked to them.

Vista gave me the a real shock when I saw that the system was using 600MB of ram from start up. So I set about changing some of the services and performance setting to see if I could change that. I prefer to at least 80 % of my ram free. I was only able to free up 200MB. So 40% of my ram is dedicated to just ruining my system.

I have had one trouble of another since I got vista. Their program compatibility system kinda works as I was able to install and use open office and FireFox. I could get it to work with PDFcreator, it just wouldn't let me install it.

Vista is a bit easier to use but that dose not account for more then half my ram disappearing. Gnome is just as easy use if not more and it only requires along with the Linux system about 220 MB on start up. Which is why I am now switching to opensuse 10.1.

I hope to do every thing this semester in Linux, and after trying out opensuse 10.1 on one of my external drives I have to say Linux is really impressing me. Novel has really done some thing impressive with suse. It is almost an replacement for Windows in terms of productivity and easy of use.

Almost a replacement but not quite. I have to manually install my Realtech 8111 network card and my Intel pro 3945 doesn't work probably. Linuxes big problem is still hard ware compatibility. Hardware manufactures are sticking to where the money is and at the moment that is with windows. The just don't put in the same effort to make hardware work with Linux.

Their are still solutions to all these problems but they are some times very complex. For instance to update the driver for my wireless card I have to download and separately install 5 different packages to get around the dependency hell in the Linux system.

I still plan to move to the more stable and efficient suse 10 .1 with Gnome as my desktop because I can Google my Linux problems and find a solution, but with windows I have to wait till some lackey at Microsoft puts out a security up date to fix my vista problems. I will and suggest any one wanting to go the vista route wait till SP1.

28 Feb 2007

Cool flash Games



A cool flash game that can be use full for passing some time, or getting out of a late night working rut. Or just late night work. Don't play it 2 much.

In response to the comment I will add the following link to this post and to my links tab
www.freeonlinegames.com. It has a good variety of games and should cater to every taste. I suggest you try it out. I have already played a few, one of my favourites is thing thing.

27 Feb 2007

FIT2001 week 1

This is a new series of post for a subject I am doing at university. Its called system Analysis and Design. unit code Fit 2001.

This first week of uni is always chaos, as nothing seams to be ready when we arrive at campus. The lecture rooms haven't got equipment connected and we don't have tutorials. This week was different, we had a tutorial and no lecture.

It wasn't a full tutorial either as we didn't have the lecture we couldn't cover all of the course content. I expect the form next week things will be very different.

This course is a second year unit and will probably be a bit more work then last year. I think it will be very interesting as we will get more into systems theory. I am built for studding I really enjoy it and could probably study any thing but IT is where my passion is.

I hope next week will be different and more organized and that things will be working like the library and the new lecture and seminar rooms will be up and running.

8 Feb 2007

I have add a list of ftp site to my blog with will allow south Africans to easily get access to gnu software with out the traffic congestion of international sites. So they will be allot faster.

Most carry the same basic software but some have more then other be sure to check all of them out.

Thing you can find on the these websites are free software foundation software and all the latest Linux distros. You will need a braud band connection for the Linux distros but may be you know a friend who can do the downloading for you.

its a conspiracy

I have been a way for a long time and I will tell you why.

There was first the talkom problem out lined below.

Then a computer problem. When I bought my last computer I search high and low to find the best and most reliable computer brand. I thought that was hp. It was priced 1000 more expensive for most of the same speck machines as other brands. I had heard a lot of good thing about hp.

I had it for a year it work fine. although it started to give problems with the power button. Then just as my warranty expired in January 2006 it completely bombed out. I have since returned it 3 time to have the same problem fixed. Then in December of this year i thought i was having the same problem.

Hp has now quoted me for 5000 mother replacement to fix the problem. Which as far as they can tell is just motherboard wear and tear. Not lighting or some thing serious just wear and tear. Let me remind you that i have only had this computer for 2 years and paid 11000 rand for it. Now it is written off.

I recommend that you should stay away for hp and choose a cheaper brand like acer or may be Toshiba. Which wont hurt as much when they break.

I say it must have been a conspiracy to keep me a way form computer and the www. I have spent almost all my time doing any thing but working with computer for about 2 1/2 months.