Take a look at My pattern for "in-place edit" for many files by merlyn for a better way of doing this. The only change i would make is to use File::Find::Rule instead of File::Find.

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)