Shell脚本读取文件路径直到文件存在

Question

用户输入文件路径，shell脚本必须检查文件是否存在，如果文件不存在，则提示输入正确的路径，直到提供正确的路径。这是我的尝试，但我不喜欢它

if [[ -z $filepath || ! -f $filepath  ]]; then
    printf "\nError: File does not exist. Try again\n"

    while true :
    do
        read -p "Please provide file path: " filepath
        if [[ -z $filepath || ! -f $filepath  ]]; then
            continue
        else 
            break
        fi 
    done
fi

这是另一个由于语法错误而失败的尝试

if [[ -z $filepath || ! -f $filepath  ]]; then 
    printf "\nError: Bad file path. Try again\n" 
    while true : 
    do 
        read -p "Please enter file path: " filepath
        case $filepath in
                "")
                    echo "Bad file path. Try again"
                    continue ;;
                ! -f)
                    echo "Bad file path. Try again"
                    continue ;; 
                *)
                    break ;;
        esac
    done

Answer 1

怎么样

until [[ -n $filepath && -f $filepath ]]; do
    read -p "Please provide file path: " filepath
done