Replaces the extension of the songs found in playlists to the same one. It will ONLY look for .m3u files.

Playlist_PathConvertor.sh

#!/bin/bash

# --- WHAT IT DOES ---
# Replaces the extension of the songs found in playlists to the same one.
# It will ONLY look for .m3u files.

# --- WHY ---
# Because I use my uncompressed library on the computer, and a compressed one 
# on portable storage or devices.

# --- HOW TO USE ---
# Pass an argument like MyPlaylistFolder/ and edit the song name
# Then save the changes to a file with a suffix

# --- ARGUMENTS ---
# What to replace inside the file
FileExtensionReplace='s/.(flac|mp3|ogg|m4a)/\.m4a/'; 
FileSuffix='CompressedVersion_';

# --- COLORS ---
NoColor='\033[0m'         # Default color
Red='\033[0;31m'          # Red
Green='\033[0;32m'        # Green
Yellow='\033[0;33m'       # Yellow

# Checking & finding the dir
if [[ $# -ne 1 ]]; then
	echo -e "${Yellow}INFO: You can add a directory as an argument!";
	echo -e "INFO: Using '.' instead.${NoColor}";
	dir="./";
elif [[ -d $1 ]]; then 
	if [[ $1 =~ /$ ]]; then
		dir="$1";
	else
		dir="$1/";
	fi;
else
	echo "$1 is NOT a directory.";
	exit 1;
fi;

# Show the files to be changed
echo "Reading $dir";
echo "Editing these files:";
for file in $dir*.m3u;
do
	filename=$(basename $file);
	if ! [[ $filename =~ $FileSuffix ]]; then
		echo -e "$filename => ${Green}$FileSuffix$filename${NoColor}";
	fi;
done

# Ask for confirmation
echo "A new file with the suffix '$FileSuffix' will be created in the target directory.";
read -p "Are you sure you want to continue? (s/N): " answer;
answer="${answer,,}";

if [[ $answer == 's' ]]; then
	for file in $dir*.m3u;
	do
		filename=$(basename $file);
		if ! [[ $filename =~ $FileSuffix ]]; then
			echo "Creating $dir$FileSuffix$filename ...";
			cat $file \
				| sed -E $FileExtensionReplace \
				> "$dir$FileSuffix$filename";
		fi;
	done
fi;

# Finish the program.
# In case it is ran without the terminal.
echo -e -n "\n\n${Red}Program finished. Press ENTER to exit.${NoColor} ";
read;