I just tried throwing a shift statement before the chomp statement in the first sub replace block. And even though this has the effect of taking the first element of @_ and placing it in $_, the changes don't make it back to the hash.

After reading 'the gory details', I found that this is because @_ is an implicit reference to the actual scalar parameters, and therefore the modifications made upon @_ make it back to my hash. But if I shift the value into $_, any changes I make won't make it back to my hash.

Is this correct? Thanks for the help.