Marcus Hellberg » Web

Blocking comment spam

admin — Mon, 04 Jan 2010 10:56:15 +0000

Despite the blog being only a few weeks old, I’m already getting a lot of spam in the comments. I have now installed the WordPress Hashcash plugin to prevent spambots from sending comments. The plugin works by requiring the browser to perform a proof-of-work to ensure that it is in fact a browser and not a bot. It also checks that trackback URLs in fact contain a link to the page and that comment IP addresses match.

The plugin should not interfere with any valid comments and allow me to use my time blogging, not filtering through heaps of spam. If it does block your comment, make sure that you have JavaScript enabled in your browser. If it still doesn’t work, send me an email at marcus [at] marcushellberg.com.

Google wave invitation giveaway

admin — Wed, 23 Dec 2009 18:57:11 +0000

As a present to all readers, I’m handing out 17 invitations to Google Wave. All you have to do to get your invitation is to be among the 17 first non-spambot commenters in this post.

Update: There are still 11 invites left.

Google math

admin — Mon, 21 Dec 2009 19:10:37 +0000

Google has apparently found my blog quite quickly, it has indexed all pages in less than three days.The funny part was seeing how Google approximated the number of indexed pages.

Sure, when there are millions of pages an estimate that is within 20 of the actual number is fine. But when there are only 24 results on three pages, an estimate of 2 is 99.92% off. A small check that the approximate number is in fact greater than the maximum search result shown on the page could probably be a good idea.

WordPress LaTeX plugin

admin — Mon, 21 Dec 2009 09:25:48 +0000

Now that I have code highlighting working, I thought that I should still look into getting some easy way to display mathematical notation. Turns out that WordPress once again delivered, there are in fact several different LaTeX plugins available.

The plugin I settled for is WP LaTeX, since it allowed me to use wordpress.com’s LaTeX server. This was an easier alternative, as Dreamhost does not have dvipng installed. On a side note, I’m impressed that they have LaTeX installed by default.

Now I only have to insert the following to create a nice looking equation:

H(z) = \frac{1}{1-2 cos(2 \pi k / N) z^{-1} + z^{-2}}

Bonus points for anyone who can identify the transfer function

Transferring Gmail to Google Apps with own domain

admin — Sun, 20 Dec 2009 15:24:35 +0000

My hosting plan with Dreamhost had an option of using Google Apps with my own domain. In practice, what I wanted was using Gmail, only with my own domain in the address.

The process of setting up Google Apps with an own domain was straight forward. All I had to do was enable Google Apps for my domain in the Dreamhost admin interface and then sign up for a Google Apps account. I had to upload a HTML-file to the root of my domain to assure that I in fact own the domain.

The big problem I had was that I currently have a Google account that I use both for my HTC Hero and for Gmail. What I really wanted was to be able to migrate that account to my own domain. This was unfortunately not possible as the two accounts are entirely separate.

I could import all of my previous mails from Gmail to the new Gmail through POP, even though it was a big pain. I could also set my old Gmail to forward any new messages automatically to the new address.

I still decided to keep using my Gmail as my primary email address because it is most convenient. The new address will, at least for the time being, stay as a secondary email mainly for this site. It is still very convenient to have an email address with an own domain and still be able to use it from anywhere using the Gmail interface and 7+ GB of storage.