Julien, the majority of comment spam can be dealt with very simply by including a turing test. On my blog, when I first started getting comment spam, I added a check box asking if the poster was a human. For a human, it’s not a massive inconvience to tick a box, but for an automated tool, it’s a major problem. Was implemented in 3 lines of html and one line of python. Since I added it, I haven’t recieved a single piece of spam.

I don’t believe it’s had a major effect on people commenting, although I currently can’t tell. I could change it to hide posts that claim to be non-human until I’ve checked them. If spam tools work out this simple problem, I could change the nature of the test to randomly change between “I am a human” and “I am not a human”. After that I could include a simple sum or some other simple question. It also has an advantage over captchas that it is accessible.

It is a simple change which massively reduces spam by increasing the cost of spamming and I’m surprised that most people don’t do something similar.

I’ve spent the weekend playing around with the new Oracle XE Debian packages in preparation of having to use them at work in the near future. I’ve written up my experiences of setting the server and connecting remote clients in my latest article.

Talking of work, we have a position for a junior support role open. If you live in or around Brighton, England and know a little bit about Linux, Debian, Tomcat, Java, PostgreSQL and Oracle and willing to learn more, have a look at the job description and get in contact.

I recently wanted to deal with docbook <ulink> elements that didn’t have any contents by displaying the url as the link text. I wanted to convert:

<ulink url="http://www.example.com">Example.com<ulink>
<ulink url="http://www.example.com"/>

to

<a href="http://www.example.com">Example.com<a>
<a href="http://www.example.com">http://www.example.com<a>

I originally had:

<xsl:template match="ulink">
   <xsl:element name="a">
      <xsl:attribute name="href"><xsl:value-of select="@url"/></xsl:attribute>
      <xsl:apply-templates/>
   </xsl:element>
</xsl:template>

This sucessfully dealt with the first form of <ulink> that had content, but not with the second example with an empty element. The solution is the use an <xsl:choose> element with a test to see if the current node has any child nodes. Using child::node() we can get any child nodes. We can then test if the node has any children using the count() function. The resulting xslt is:

<xsl:template match="ulink">
   <xsl:element name="a">
      <xsl:attribute name="href"><xsl:value-of select="@url"/></xsl:attribute>
      <xsl:choose>
         <xsl:when test="count(child::node())">
            <xsl:apply-templates/>
         </xsl:when>
         <xsl:otherwise>
            <xsl:value-of select="@url"/>
         </xsl:otherwise>
      </xsl:choose>
   </xsl:element>
</xsl:template>

Andrew, yet at the other end of spectrum, given that America is constitutionally secular, they have “in God we trust” on their currency and don’t trust atheists. Their “Pledge of Allegiance” was changed in 1954 by Dwight D. Eisenhower to include “under God”. This pretty means I’m unable to visit the country. I think that’s worse than trying not to offend anyone, no matter how misguided.

Sometimes you need to generate several SSL certificates, but don’t want to pay money to a Trusted Root, and self-signed certificates just won’t cut it. If you’ve ever had this dilemma, just for you, here’s an article describing how to set up your own trusted root certificate and how to import it into several common applications. If you want me to add your favourite application, feel free to email me with instructions and screenshots if appropriate.

I upgraded my atom feed to atom 1.0 during the week. This appears to have broken my entries on Planet Debian. If anyone has any ideas on what I can do to make planet like me with a valid atom 1.0 feed, please let me know.

Update: I’ve changed my feed from having html content to xhtml, which isn’t encoded. Hopefully Planet will like this. If not I’ll have to fix it in the morning.

Over the weekend, I managed to revive my main desktop machine, which as spent the last 15 months turned off under a desk because it was showing some odd behaviour and didn’t have time to fix it. I’ve upgraded it to the latest sid and given it to my girlfriend to use instead of the Windows machine she had been using. She appears to have fallen in love with tuxpaint. :)

In the process of setting it up I discovered printconf, which automatically sets up parallel and USB printers under cups. Plugged in my printer, went to print in firefox and there was the printer. These things just get easier and easier. Gone are the days when you spent hours writing a printcap entry for your printer. One thing I would like is for DBus support in CUPS so I know when the print job has finished.

Just finished writing an article on PostgreSQL user administration. Go read it.

Came back from a nice walk on the seafront, including a 30 minute professional firework display from a boat 20 meters offshore and about 50 people watching, to find that someone had attempted to attack my blog comment to send spam. Fortunately according to my mail logs, nothing went out, but it did make me go through and read the comment plugin code. I did wonder if every suitable field had been cleaned and have now made sure that it is. Looks like it came from several IP addresses over a 5 minute period and got past my (admittedly very) simple turing test, so I don’t think it was an automated script. For an example of the attacks, check out this old posting.

Clint, I don’t know about Belgium, but in the UK, the norm is a month for most people and 3 months for senior members of staff. Of course, you may or may not be given work to do during that period. Usually your employers will want you to document and help hand over to a new person. However if you have a bad relationship with your employers, they may put you on garden leave where you arent in the office, but are being paid. Presumably this is to stop you stealing their data or doing some other malicious act. All this stuff is normally written into your employment contract. Without one it is possible to leave your employer within a week.

Opening XSane results in: