-- 定义基础URL
local base_url = "https://www.xxx.com"

-- 函数：验证输入是否合法
local function validate_input(input)
    local a, b = input:match("^(%d+),(%d+)$")
    if a and b then
        a = tonumber(a)
        b = tonumber(b)
        if a <= b then
            return a, b
        end
    end
    return nil
end

-- 函数：拼接URL列表
local function generate_urls(a, b)
    local urls = {}
    for i = a, b do
        table.insert(urls, base_url .. "/" .. i)
    end
    return urls
end

-- 函数：执行URL并处理失败情况
local function execute_urls(urls)
    local failed_urls = {}
    for _, url in ipairs(urls) do
        local success = os.execute("curl -I " .. url) -- 使用curl命令检查URL是否可访问
        if not success then
            print("执行失败: " .. url)
            io.write("是否重试? (y/n): ")
            local retry = io.read()
            if retry == "y" then
                success = os.execute("curl -I " .. url)
                if not success then
                    table.insert(failed_urls, url)
                end
            else
                table.insert(failed_urls, url)
            end
        end
    end
    return failed_urls
end

-- 函数：将失败的URL保存到文件
local function save_failed_urls(failed_urls)
    if #failed_urls > 0 then
        local file = io.open("failed_urls.txt", "w")
        if file then
            for _, url in ipairs(failed_urls) do
                file:write(url .. "\n")
            end
            file:close()
            print("失败的URL已保存到 failed_urls.txt")
        else
            print("打开文件失败。")
        end
    else
        print("所有URL执行成功，没有失败的URL。")
    end
end

-- 主程序
while true do
    io.write("请输入起始数字a和终止数字b（格式为a,b）或输入re重新开始: ")
    local input = io.read()
    if input == "re" then
        print("重新开始...")
    else
        local a, b = validate_input(input)
        if a and b then
            local urls = generate_urls(a, b)
            local failed_urls = execute_urls(urls)
            save_failed_urls(failed_urls)
            break
        else
            print("输入格式不正确或a > b，请重新输入。")
        end
    end
end