Installing CDAX on Linux

The text below applies for the CDAX version 5.4 (and will apply for past and future versions if the issues are not solved).

First and foremost, for the moron who developed the installer and hosted it at the site ... Thanks for nothing !!!. Go and;

a. Read the installer creator's manual before writing installers with it.
b. Learn Linux before pretending you know how to write installers for it.


For the rest of you guys here's how to clean up this mess and set up the CDAX software on your preferred Linux distro.

After downloading the .bin file and giving it execute permissions, don't even think about running it again and again. It's a bloody waste of time. Just go to step 1 below.

Before going to step 1, let's dissect what this guy has done. After running the installer and it dying out, there will be 2 log files generated in the same directory. These are named 'errors.log' and 'jinstall.log'. The most important information can be found on the latter. Going through it we can see what the 'wannabe' installer maestro has done.

First, he has turned 'off' the JVM search functionality, which means irrelevant of the fact that I already have an up-to-date JVM installed, the installer will install it's own JVM. (In case you were unfortunate enough to download that 30 MB installation using a dial-up connection, keep in mind that the bulk of that file was the JVM and not the actual CDAX software. He should have put two installers with/without the JVM included.)

Then after extracting his JVM to my hard drive, the installer tries to execute the 'java' executable inside it, without bothering to set execute permissions first. Obviously the installer goes south from that point on.

So that about sums it up for the dissection. I hope I wasn't too harsh on the guy. On second thoughts... No I don't hope so. If you are putting out a software (along with the image of your company at stake) on the line, you should spend time to find out whether the installer works on all platforms. I wonder what the story is with the Macintosh users.


Now let's see how I got this thing working in my Ubuntu Breezy.

Step 1: Run the installer with sudo (or as root, whatever fancies you ...)
Step 2: After the installation fails :) Go to the directory where the installer puts its JVM in. That would be /usr/local/bin/jvm/jre1.5
Step 3: Give the 'java' executable execute permissions, so that it can be executed by a normal user.
Step 4: Run the installer again as a normal user. Voila !!! The wizard starts and it's point and click time from there on..
Step 5: Now to get rid of this VM (if you already had one installed and this was force installed). Deleting this VM and creating a simlink to your original 'java' executable should cure that irritation.


Hope this helps ....

Interviewing Developers

I came across a really interesting post from Joel, while doing some background work for an industrial day. I'm in a panel to hire new interns who might be potential employees.

I loved the part that says,

"Smart is hard to define, but as we look at some possible interview questions we'll see how you can ferret it out. Gets Things Done is crucial. People who are Smart but don't Get Things Done often have PhDs and work in big companies where nobody listens to them because they are completely impractical. They would rather mull over something academic about a problem rather than ship on time. These kind of people can be identified because they love to point out the theoretical similarity between two widely divergent concepts. For example, they will say "Spreadsheets are really just a special case of programming language" and then go off for a week and write a thrilling, brilliant white paper about the theoretical computational linguistic attributes of a spreadsheet as a programming language. Smart, but not useful."

Is Wikipedia a threat or a menace?

Is Wikipedia a threat or a menace? by ZDNet's Dana Blankenhorn -- Just like the GPL, Wikipedia carries with it responsibilities along with rights.

WiFi (non)Security ....

How can I protect my wireless network ? Well I found what NOT to use


1. Mac Filtering

Spoof the mac address in linux by ;

/etc/init.d/networking stop
ifconfig eth0 hw ether 00:01:02:03:04:08 <== desired mac :)
/etc/init.d/networking start

More info on other systems found here


2. WEP (Wireless Equivalent Privacy)

This method, as it seems was pretty weak from the begining. There's a step-by-step approach to cracking it here

Hmmm ... try kismet and airsnort ... I rest my case ;)


With these two gone, The Other alternatives AFAIK would be to;

1. Hide the SSID
2. Disable DHCP and assign static non-routable IPs
3. Use WPA instead of WEP

I found a good intro here, while googling, which gives a step by step guide to configure your router for security.

Java JRE/JDK Installation on Debian with java-package

An excellent article I found while doing research to create Debian packages for Sun's JDKs for our Taprobane distro.

Tracking down causes of exceptions in Eclipse

NOTE: I found this in a Blog somewhere.. Thanks and due credits to the author, who ever he/she is :)

BEGIN QUOTE

If you like me is getting tired of seeing "Unhandled event loop exception, Reason: someexception" and no stacktrace in Eclipse then try the following:

Create a file e.g. .eclipseoptions with the following contents:


# Turn on debugging for the org.eclipse.ui plugin.
org.eclipse.ui.ide/debug=true
# Show a dialog with details button when an internal error occur.
org.eclipse.ui.ide/debug/internalerror/openDialog=true
# Print exception stacktrace to console
org.eclipse.ui.workbench/debug=true


and then run eclipse with -debug .eclipseoptions and you will get the full stacktrace
as normal in the log but also on the console (clickable) and in a dialog when the exception occurs - no need to go looking in the log what just happend.

p.s. try to include the following too:


# Enable heap status monitoring
org.eclipse.ui/debug=true
org.eclipse.ui/perf/showHeapStatus=true


Gives you a nice hint about memory you are "utilizing"

END QUOTE

FOSSSL Codefest

Well the codefest is in progress as part of our FOSS Week. Although I was involved in organizing, didn't take part in the actual event, since I couldn't see how I cn contribute ... being a Java guy :(

FOSS in Sri Lanka

Sri Lanka will be hosting the FOSS conference this time and more details here

My nx9040

Introducing my laptop, the HP nx9040, which I bought recently and consider a most valuable addition to my arsenal.

QUICK SPEC:

• Intel Pentium M-II 1.6G with 2M Cache
  
• 512M DDR SDRAM
• 15.1" TFT XGA LCD (1024 * 768) with Intel 64M (32M shared) Video Card
• 40GB Hard Drive
• Internal DVD/CD+RW Drive
• Stereo 16-bit sound System/Speakers
• Built-in 10/100 Network Card
  
• Built-in V90/92 56K Modem
  
• Li-Ion Battery (lasts for upto 4 hours in Windows 3.5 in Linux)
• 2x Fast USB 2.0 (Universal Serial Bus) Ports
• 1x IEEE 1394 (i.LINK/Firewire) Port
• 1x S-Video Out
• 1x VGA Out (ext monitor)
• 1x RJ-11 for Modem
• 1x RJ-45 for LAN
• 2x PCMCIA
• 1x Audio Out
• 1x MIC In

Cooling my Linux laptop (Updated ...)

I came up with a rule (ok.. now 3 rules) to keep my machine (HP NX9040, Centrino 1.6 GHz, 512MB RAM, 40GB Hard Drive) cool with 'cpufreqd' when on AC power. Usually what happens with the default configurtion is that 'cpufreqd' makes the machine stay cool (by reducing CPU frequency appropriately) and in power saving mode while on batteries and returns to full power + full CPU frequency mode on AC power.

This makes the machine heat up unnecessaryly even when it is idle.

By adding the rule below in the /etc/cpufreqd.conf file, right before the 'AC_on' rule, I managed to get my machine temp down by 10 degrees (yes... you read right) when it's idle :)

Add the new rule to 'cpufreqd' and restart the daemon. (/etc/init.d/cpufreqd restart)

What the rules do is, check the CPU utilization level and if it is below a certain percentge then send the machine to lo_boost/medium_boost/hi_boost profile, which brings the CPU frequency down to appropriate ranges as necessary.

Oh... make sure you turn off your fancy CPU hungry OPEN GL screen savers as well and revert to 'blank screen' to get the max temperature drop possible.

Laid back ....

------------------------------------------------------------

# power down when AC and idle (utilization 70% to 100%)
# Author: Tyrell Perera
[Rule]
name=AC_on_idle_3
ac=on # (on/off)
cpu_interval=70-100
profile=hi_boost

# power down when AC and idle (utilization 30% to 80%)
# Author: Tyrell Perera
[Rule]
name=AC_on_idle_2
ac=on # (on/off)
cpu_interval=30-80
profile=medium_boost

# power down when AC and idle (utilization 0% to 40%)
# Author: Tyrell Perera
[Rule]
name=AC_on_idle_1
ac=on # (on/off)
cpu_interval=0-40
profile=lo_boost

# originally the only AC on rule ... replaced by the three above
# full power when AC
#[Rule]
#name=AC_on
#ac=on # (on/off)
#profile=hi_boost

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