shell function to play a cd from a collection

choose_cd.sh

ttf() {
    if [ -z "$1" ]; then
        echo >&2 Please specify CD number
        return 1
    fi

    _cd_num=$1
    set --

    _dir=$(echo ~/Music/Tunnel*/*_${_cd_num}-*)

    _i=0

    for _mp3 in "$_dir"/*.mp3; do
        _i=$((_i + 1))
        set -- "$@" $_i "${_mp3##*/}"
    done

    whiptail=whiptail

    if ! command -v whiptail >/dev/null; then
        whiptail=dialog
    fi

    _cd=$($whiptail --title "Tunnel Trance Force Volume $_cd_num" --menu "Choose CD to play:" 15 70 $_i "$@" 3>&1 1>&2 2>&3)

    [ $? != 0 ] && return 1

    _cd_file=$(eval echo \$"$((_cd * 2))")

    mpv "${_dir}/${_cd_file}"

    unset _cd_num _dir _i _mp3 _cd _cd_file
}