メニューに使えるシェル関数。外部依存はありません。

SelectMenu.sh

SelectMenu(){
    local CaptureSpecialKeys Choices=("$@") CurrentChoice=0 Key=""

    CaptureSpecialKeys(){
        local SELECTION rest
        IFS= read -r -n1 -s SELECTION
        #echo "$SELECTION" | hexdump >&2
        if [[ $SELECTION == $'\x1b' ]]; then
            read -r -n2 -s rest
            SELECTION+="$rest"
        else
            if [[ "$SELECTION" == '' ]] ;then
                echo "Enter"
                return 0
            else
                read -r rest
                echo "$SELECTION$rest"
                return 0
            fi
        fi

        case $SELECTION in
            $'\x1b\x5b\x41') #up arrow
                echo "Up"
                ;;
            $'\x1b\x5b\x42') #down arrow
                echo "Down"
                ;;
            $'\x1b\x5b\x43') #right arrow
                echo "Right"
                ;;
            $'\x1b\x5b\x44') #left arrow
                echo "Left"
                ;;
            $'\x20') #space
                echo "Space"
                ;;
        esac
    }

    #-- ここからメニュー
    while [[ "$Key" != "Enter" ]]; do
        # メニューを表示
        for i in "${!Choices[@]}"; do
            if [[ "$i" = "$CurrentChoice" ]]; then
                printf "\033[4m" && printf "\033[1m" # 太字+下線
                echo " > $i: ${Choices[$i]}"
            else
                echo "   $i: ${Choices[$i]}"
            fi
            printf "\033[0m" # リセット
        done

        # キー検知
        Key="$(CaptureSpecialKeys)"
        case "$Key" in
            Up)
                (( "$CurrentChoice" != 0 )) && CurrentChoice=$((CurrentChoice - 1))
                ;;
            Down)
                (( "$CurrentChoice" != "${#Choices[@]}" - 1 )) && CurrentChoice=$((CurrentChoice + 1))
                ;;
        esac

        # メニューを削除
        # shellcheck disable=SC2034
        for i in $(seq 1 "${#Choices[@]}"); do
            printf "\033[1A"
            printf "\033[2K"
        done 
    done 

    echo "${Choices[$CurrentChoice]}"
}