How to rename file without moving?

[SampsonF]

I have files under folder tree like:

/Date/YY/YYmm/YYmmdd/UPPER123.jpg

I just want to rename the file without moving folders.

I tried this command:

exiftool '-testname=%lf%-c.%le' -r /Date/YY

Result:
For filenames already in lower case, a count is always added
For filenames having Upper case, renamed to lower case without counter

Question:
How can I prevent the change of files with names already in all lower case?

[Phil Harvey]

Try this:

exiftool '-testname=%lf%-c.%le' -if '$filename ne lc $filename' -r /Date/YY

- Phil