Mac OS X Terminal batch rename...but with folder paths - macos

Question

I tried incorrectly to add my question on to a very similar thread w/ good solutions here:
mac os x terminal batch rename
I have essentially the same question, but I'm wanting to do this and change the folder path when renaming. Here is what I asked:
Would any of these solutions work to change underscores to a folder path? For example, I have mbox files on one level that need to be nested, such as:
TopLevel_NextLevel_mbox
TopLevel_NextLevel_FinalLevel_mbox
I'd like to automatically put these in a hierarchy like so:
TopLevel/NextLevel/mbox
TopLevel/NextLevel/FinalLevel/mbox
Can this be done? When I try simple replacement with "/", I get this:
fred$ for f in *_mbox; do mv "$f" "${f/_//}"; done
mv: rename TopLevel_NextLevel_mbox to TopLevel/NextLevel_mbox: No such file or directory
Looks like it just tries to sub in the "/", but then gets confused because there is no current folder TopLevel w/ NextLevel_mbox inside it...
Thanks,
Fred

Answer 1

The basics of making this work starts with the process of creating an array from the current directories that contain *mbox. Each array key then contains the resulting delimited word found between the underscores:
TopLevel_NextLevel_mbox
Is transformed into an array like this:
( TopLevel, NextLevel, mbox )
From there we create the first directory TopLevel then perform a cd followed by mkdir on the next key — repeating the process until there are no more keys. By doing this each array key creates a new nested directory (as a bonus it also copies any data from the original directory into the new one whilst keeping it's structure).
Create Nested Folders from Original
#!/bin/bash
DIR=$PWD
for f in *mbox
do cd $DIR
if [[ -d $f ]]; then
ARR=(${f//_/ }); n=0
for i in "${ARR[#]}"
do echo $n
if [[ $n -eq 0 ]]; then
mkdir -p $i && cp -R $f/* $i && cd $_
else
mkdir -p $i && cd $_
fi
let n++
done
fi
done
Pseudo One-liner
DIR=$PWD; for f in *mbox; do cd $DIR; if [[ -d $f ]]; then ARR=(${f//_/ }); n=0; for i in "${ARR[#]}"; do if [[ $n -eq 0 ]]; then mkdir -p $i && cp -R $f/* $i && cd $_; else mkdir -p $i && cd $_; fi; let n++; done; fi; done
This is the same exact script as the one above it, however, it's formatted to be one line. * The script leaves the original directories intact (I'll leave the exercise of removing them up to the OP).