Twenty two days ago, my periodically running script ceased to produce any check-ins on Brightkite. A quick look at the output showed that the format of the returned place object had changed. Had I used proper XML parsing, that would not have been a problem – but I’m using homely grep, sed and awk… Not robust code in any way, especially when dealing with XML. At least you get a nice illustration of why defensive programming with proper tools is good for you.

So here is a new update of latitude2brightkite.sh – a script that checks-in your Google Latitude position to Brightkite using the Brightkite API and the Google Public Location Badge. Description of the whole contraption may be found in the initial announcement.

The changes are :

% diff latitude2brightkite_old.sh latitude2brightkite.sh
69,70c69,70
< id=`wget -qO- "http://brightkite.com/places/search.xml?q=$latitude%2C$longitude" | grep "<id>" | sed s/\ \ \<id\>// | sed s/\<\\\/id\>//`
< place=`wget -qO- "http://brightkite.com/places/search.xml?q=$latitude%2C$longitude" | grep "<name>" | sed s/\ \ \<name\>// | sed s/\<\\\/name\>//`
---
> id=`wget -qO- "http://brightkite.com/places/search.xml?q=$latitude%2C$longitude" | grep "<id>" | sed s/\ \ \<id\>// | sed s/\<\\\/id\>// | tail -n 1`
> place=`wget -qO- "http://brightkite.com/places/search.xml?q=$latitude%2C$longitude" | grep "<name>" | sed s/\ \ \<name\>// | sed s/\<\\\/name\>// | md5sum | awk '{print $1}'`

I know I should use a revision control system… Posting this diff that does not even fit this blog is yet another reminder that a revision control system is not just for “significant” projects – anything should use one and considering how lightweight Git is in comparison to Subversion, there really is no excuse anymore.

Back to the point… To get the place identifier, I now only take the last line of the field – which is all we need. I mdsum the place name – I only need to compare it to the place name at the time of the former invocation, so a mdsum does the job and keeps me from having to deal with accented characters and newlines… Did I mention how hackish this is ?

Anyway… It works for me™ – get the code !