Fix broken filenames. Removes all non-alphanumeric characters from directory and filenames from a given directory and copies them into the current directory. I'm using this to help me organize and backup my music on multiple devices.

sanitize.sh

#!/bin/bash
#
# Sanitizes all files in the given path
# and makes them lowercase too.
#
# param 1: source directory
# param 2: target directory

shopt -s extglob; 

# copy as default, you have to change this if you want to move files
MV=cp -v
#MV=mv -v

source="$1"
target="$2"

find ${source} -depth -type f -print | while read path
do
  filename=$(basename "$path")
  directory=$(dirname "$path")
# remove original path from target to avoid deep path in target directory
  directory_clean=${directory#$source}
  target="$(dirname "$target")/$(basename "$target")"

# remove invalid chars from directory/filename
  directory_clean="${directory_clean//+([^[:alnum:]_-\.\/])/_}"
  filename_clean="${filename//+([^[:alnum:]_-\.])/_}"

  mkdir -vp "${target}/${directory_clean,,}"
  ${MV} "$directory/$filename" "${target}/${directory_clean,,}/${filename_clean,,}"
done