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

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

Laptop Power Optimizer for Linux

cpufreqd is a really cool power manager for your linux laptop. After getting my laptop and setting it to dual boot winXP and Linux, I noticed a 10 degree (centigrade) temp difference between windows and linux, linux being in the higher range.

After getting cpufreqd, they both run on virtually identical temperatures and the battery life is virtually same in both as well.

Thanks Bud for the pointer to this software :)

Changing the User Agent in Firefox

Interesting Firefox extension which allows you to change the Browser and OS identification sent by Firefox. After intalling, a menu appears under 'Tools', which allows you to do this.

Bottom line? I can access my HSBC internet banking from Linux now, which wasn't possble earlier :)

Updating to JDK 1.5.0 on mepis

Mepis comes with the Blakdowns version of java, which is 1.4.2_04. I updated it with the latest JDK from sun as follows.

- Make sure you have execute permisions for the .bin file downloaded from sun

# ./your-downloaded-jdk.bin

# vi .bashrc

- Add the following two lines

export JAVA_HOME=your-new-java-home

export PATH=$PATH:your-new-java-home/bin

# su -

$ cd /usr/bin

$ rm java

$ ln -s 'your-new-java-home/bin/java' java

$ rm javaw

$ ln -s 'your-new-java-home/bin/javaw' javaw

Now you can test this with typing java -version on the shell

# java -version

java version "1.5.0"

Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)

Java HotSpot(TM) Client VM (build 1.5.0-b64, mixed mode, sharing)

LINUX and ACPI

Well as it sems, these two are not doing well in case of laptops. Especially if you want to close the lid expecting the damn screen to be turned off by the OS.

One guy has posted a solution here. I haven't teste this on my laptop yet, but will try to do so soon.

Automatic USB detection and Mount

I managed to get my USB flash drive to automaticaly mount in Linux and the steps are below;

Get root first of all ;)

• # apt-get install pmount hal udev
• # vi /etc/default/hal and comment out the line found there (#DAEMON_OPTS=--drop-privileges)
• # cd /etc/hal/devices.d
• # ln -s /usr/sbin/hal 50-fstab-sync.hal

• make sure you enable device icons in KDE (using control center -> Behaviour -> 'Device Icons' tab -> select 'Show Device Icons' -> Select all you want to be seen in the desktop)
• restart the session

-- Thank you Anuradha and Bud for the research :)

Lap Top search ...

I've been searching for a laptop for the past few days. Came across several candidates 'Acer Ferrari' being the coolest thing I saw. But my mind is set on the HP NX9040 which has all the features I want and comes closer to my budget as well.

IMHO Intel Centrinos are a bit overpriced at the moment. But I need a laptop NOW and there you have it ....

Gosling on Java in it's 10th Aniversary

Some interesting facts from the creater on his creation at it's 10th aniversary.

Yes it works .....

The previous post being published means that the app works on my Debian based, Simply Mepis linux distro....

gnome blog poster

I just came across this application where you can post to your blog from your desktop. Pretty cool ... I tried a KDE equivalent earlier but didn't quite work with Blogger, despite having more functionality.

Get it from here

Software is like sex ;)

Some interesting quotes on programming.

My Favourite, "Software is like sex: It's better when it's free. (Linus Torvalds)"