I'm looking for a quick way to rename a bunch of files and folders all to uppercase.
This is totally off the wall, but I believe that MP3 Tag Studio would do what you want.
In "Browse/edit tags", choose the "Show all filetypes" box.
In "Direct rename files",
(1) choose advanced mode,
(2) and in General settings choose "Case fix and replace".
(3) Set "Expected file name format" to "<Title>",
(4) and "Output file name format" to "<Title>"
(5) in "Setup", set "Capitalization mode" to "Full uppercase".
(6) Check the "Include subdirs" box
Go as far up the directory tree as you need to go (Root?) and click Execute.
OK, I just tested this on a temporary directory, 19 folders and subfolders, 525 files, about 3.5 GB. It worked, it took 0.8 seconds to run. That's the good news. The bad news is that it only changes the filenames, and
not the directory names. But maybe you can modify your script to do just the directories after the filenames are changed?
tanstaafl.