Renaming Subdirectories and Files - bash

Question

I have a script using a for loop that would rename folders and files. The script would take the list of files and folders and rename them conditionally. I would invoke the file using the command:
find test/* -exec ./replace.sh {} \;
My replace.sh script would contain something similar to:
for i in $#
mv $OLDFILE $NEWFILE
done
$OLDFILE and $NEWFILE has been set previously and I don't believe any problems will arise from them.
My problem arises when I hit upon subdirectories. Originally, I would have folders like:
folder_1
-file1
-file2
When my script changes folder_1 into folderX1, the next argument, folder_1/file1 woudl be invalid as the changed path would be folderX1/file1. I figured I could create a stack with a list of folders that is being changed and pop them out later to rename the files but this seems hard on bash. Is there a better method that I am missing?
P.S I could run the program several times to go through all the subdirectories but this doesn't seem efficient.

Answer 1

You can add -depth to the find command. This will process the directory's files before the directory itself. See man find for details.

Answer 2

Your find usage is problematic. The first option is the start location for the search, so you don't want to use a glob there. If you want only the files in test/ and not any of its subdirectories, use the -depth option, as Olaf suggested.
You don't really need to use a separate script to handle this rename. It can be done within the find command line, if you don't mind a little mess.
To handle just the top-level of files, you could do this:
$ touch foo.txt bar.txt baz.ext
$ find test -depth 1 -type f -name \*.txt -exec bash -c 'f="{}"; mv -v "{}" "${f/.txt/.csv}"' \;
./foo.txt -> ./foo.csv
./bar.txt -> ./bar.csv
$
But your concern is valid -- find will build a list of matches, and if your -exec changes the list out from under find, some renames will fail.
I suspect your quickest solution is to do this in TWO stages (not several): one for files, followed by one for directories. (Or change the order, I don't think it should matter.)
$ mkdir foo_1; touch red_2 foo_1/blue_3
$ find . -type f -name \*_\* -exec bash -c 'f="{}"; mv -v "{}" "${f%_?}X${f##*_}"' \;
./foo_1/blue_3 -> ./foo_1/blueX3
./red_2 -> ./redX2
$ find . -type d -name \*_\* -exec bash -c 'f="{}"; mv -v "{}" "${f%_?}X${f##*_}"' \;
./foo_1 -> ./fooX1
Bash parameter expansion will get you a long way.
Another option, depending on your implementation of find, is the -d option:
-d Cause find to perform a depth-first traversal, i.e., directories
are visited in post-order and all entries in a directory will be
acted on before the directory itself. By default, find visits
directories in pre-order, i.e., before their contents. Note, the
default is not a breadth-first traversal.
So:
$ mkdir -p foo_1/bar_2; touch red_3 foo_1/blue_4 foo_1/bar_2/green_5
$ find . -d -name \*_\* -exec bash -c 'f="{}"; mv -v "{}" "${f%_?}X${f##*_}"' \;
./foo_1/bar_2/green_5 -> ./foo_1/bar_2/greenX5
./foo_1/bar_2 -> ./foo_1/barX2
./foo_1/blue_4 -> ./foo_1/blueX4
./foo_1 -> ./fooX1
./red_3 -> ./redX3
$