Archive for the ‘Uncategorized’ Category

Interesting HTTP header fields

In Uncategorized on January 3, 2011 at 4:31 pm

Some interesting HTTP header fields from Wikipedia:

  • If-Modified-Since — Caching
  • If-Match — ETag (for a PUT?)
  • If-None-Match — ETag, for caching
  • Content-Disposition — For showing a “File Download” dialog box
  • Content-MD5
  • X-Frame-Options — “Clickjacking” protection
  • X-Content-Type-Options — Tell IE not to ignore the declared content type

How to install Adobe Flash

In Uncategorized on October 8, 2010 at 4:06 pm

It’s surprisingly difficult to install the Adobe Flash player without their license manager. The following worked from me:

  1. Save the Flash Player uninstaller to the desktop.
  2. Save the Flash Player installer to the desktop. If that page gives you trouble, try the direct link instead. If you use Flash in Internet Explorer, also save the Flash installer for IE.
  3. Exit all open browsers.
  4. Run the uninstaller.
  5. Run the installer(s).
  6. Verify that you’ve successfully installed the latest version on the About Flash page.

This is taken from the following thread at mozillaZine.

FSF won’t answer GPL question

In Uncategorized on September 13, 2010 at 10:28 pm

Via a GCC mailing list thread.

> > It’s my understanding that FSF legal department has consistently refused
> > to answer such questions as this.
> Do you have a quote for that, please?
How do you quote somebody who DOESN’T answer?

It makes perfect sense when you think about it.

The Biggest Number

In Uncategorized on July 27, 2010 at 10:52 pm

I don’t like to post links, but I find this very interesting.

Who Can Name the Bigger Number? by Scott Aaronson

It touches on so many fascinating topics.

I found it via Hacker News.

Which pointed me to the original contest and the results. The results are also available here.

Related to this, I didn’t know that Douglas Hofstadter once ran a largest number game in the June 1983 issue of Scientific American.

Distributing Linux binaries

In Uncategorized on July 21, 2010 at 7:26 pm

In this post I will talk about how to distribute binary applications on Linux. My target is to describe how to distribute a binary that will run on as many distributions as possible, without relying on a package manager such as RPM.

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BusyBox tar oddity

In Uncategorized on April 23, 2010 at 8:22 pm

Some versions of BusyBox tar will refuse to extract tar archives created with newer versions of GNU tar.

I tested with BusyBox v0.61.pre (2002.09.06-11:28+0000), but the problem may be present in newer versions of BusyBox. BusyBox v1.2.2 (2007.03.07-20:42+0000) doesn’t exhibit the problem.


tar will appear to extract the file, but won’t actually:

# tar xvf payload.tar
# ls -al payload
ls: payload: No such file or directory

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I have a “SAMSUOG!” CD-ROM drive

In Uncategorized on April 23, 2010 at 8:10 pm

Yes, that’s right, I have a “SAMSUOG!” CD-ROM drive, not Samsung.

This drive was working fine recently, and then it broke. Broke such that I can still read CD-ROMs, but not write them.

Doing a web search, I found out that this is caused by corrupt firmware on the CD-ROM drive.

So, as I was saying, I need a new CD-ROM drive.

Lines and numbers, signifying nothing

In Uncategorized on March 11, 2010 at 8:21 pm

This fantastic gem is from rate comparison available at the Pennsylvania Insurance Department website.

Pennsylvania homeowner's insurance comparison

Homeowner's insurance comparison, or perhaps random numbers

Any idea what this means?

Anti-virus spyware

In Uncategorized on March 4, 2010 at 4:09 pm

Someone at work was recently infected by malware posing as anti-virus software.

Screenshot of malware posing as anti-virus software

Malware posing as a virus-scanner

I don’t find it very surprising seeing how realistic it looks. Of course, if this was Internet Explorer, maybe the toolsbars could be hidden.

Some basic rules of internet safety:

  • Don’t run Internet Explorer (I recommend Google Chrome, or FireFox with the Adblock extension).
  • Don’t run as Administrator.
  • Don’t download and run any executable from the internet. For the rare times that you must, make sure you verify the origin.
  • Use different passwords for websites with differing values (e.g. your bank password should not be reused at  I recommend using a password manager.
  • Never, ever give out your password.  If you don’t use a password manager, then read the address correctly: is not the same as

Book Review: Program Development in Java

In Uncategorized on February 23, 2010 at 9:00 pm

Title: Program Development in Java

Author: Barbara Liskov, John Guttag

Publisher: Addison-Wesley

Year: 2001

I read this book because of Barbara Liskov. I first heard of Liskov via the Liskov substitution principle (also see 1 2). The book has a very academic flavor: there is discussion of a representation invariant, the meaning of subtypes, and the Alloy specification language is used, along with a novel notation for depicting dependencies between modules.

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