Thanks for that tobyink. In my specific case there is no need for escaping as everything I will be using as a key or value is guaranteed to only consist of [a-zA-Z_-] and this is enforced at the data entry stage.

BTW I have been doing some benchmarking and so far sprintf rocks, though I have a feeling some of this is to do with the extra method call overhead using a module. Haven't included the newer ones below yet.