Are the answers around somewhere. I need to kind of compare!
Sorry for the delay in getting back to you. You can download the example files for this book at http://examples.oreilly.com/9780596000806/begperlbio_all.zip. The author's suggested solutions can be found in in the exercises folders in that zip file. For example, the suggested solution for Exercise 4.6 is in begperlbio_examples-and-exercises/exercises_part1/exer04.06
In the book's introduction, the author says:
Anyone wishing to learn Perl programming for bioinformatics should try the exercises found at the end of most chapters. They are given in approximate order of difficulty, and some of the higher-numbered exercises are fairly challenging and may be appropriate for classroom projects. Because there's more than one way to do things in Perl, there is no one correct answer to an exercise. If you're a beginning programmer, and you manage to solve an exercise in any way whatsoever, you've succeeded at that exercise.
Hope this helps!