Define span of multiple folders and join mp3s inside - useful for audio that

mp3cat-mdir

#!/bin/bash
# Define span of multiple folders and join mp3s inside - useful for audio that
# spans more than one CD

# Display usage if no parameters given
if [[ -z "$@" ]]; then
  echo " ${0##*/} <dir1> <dir2> <filename>.mp3 - folder span mp3 join"
  exit
fi

# Create mp3 filelist
declare -a filelist

for (( i="$1"; i <= "$2"; i++ ))
  do
    suffix=$(printf '%03d' "$i")
    f="Unknown Artist - Unknown Album $suffix"
    filelist+=("$f"/*.mp3)
  done

# Concatenate mp3s
cat "${filelist[@]}" | mp3cat - - > "$3".mp3