No, these aren't homework problems from a computer science class. They're interesting head-scratchers based on a data-analysis project I worked on recently, with the data 'reimagined' here for simplicity but with the underlying problems intact. We'll start with boys and girls, which are text files…

The complicated-looking script at the end of this article is in two parts. The first part detects the changes made when a data table is edited, and reports the changes as a plain-text logfile. It's a straightforward bit of shell scripting based on the diff command. The second part of the script…