hi, could I use grep to add all the filenames of more than 1 dir into a single sorted array

Yes.

(LAUGHS AT OWN JOKE)

Oh, man, I really need a life.

*ahem* Okay, this probably can be done if you can provide grep with a list of the directories (with globbing for the files in those directories). It requires a bit of programming, though, more than a one-line command.

However, as has been mentioned previously in this thread, you're probably better off using sort instead. You'd probably need to use it anyway in the grep solution, so I'd recommend that approach.