I would like to see something on the role of regular expressions in taint checking.

I liked the section explaining the security implications of embedding perl code in regular expressions.

It would be helpful to have a full section on validating program input. Perl is a great tool for validation, and it would be helpful to show techniques for doing it correctly.

On a lighter note, in one example, an example uses the string "36, 22, 74, hike!" It would be even better to use a more realistic signal, as explained here.

Thanks for the preview of the book! I'll be sure to buy a copy when it comes out.

It should work perfectly the first time! - toma