lua获取喜马拉雅音频地址

#!/usr/bin/lua5.1
--需要luacurl http://luacurl.luaforge.net/
--luajson https://github.com/mbalmer/luajson
require("luacurl")
require(‘json‘)


function get_html(url, c)
    local result = { }
    if c == nil then
        c = curl.new()
    end
    c:setopt(curl.OPT_URL, url)
    c:setopt(curl.OPT_WRITEDATA, result)
    c:setopt(curl.OPT_WRITEFUNCTION, function(tab, buffer)     --call back函数，必须有
        table.insert(tab, buffer)                      --tab参数即为result，参考http://luacurl.luaforge.net/

        return #buffer
    end)
    local ok = c:perform()
    return ok, table.concat(result)             --此table非上一个table，作用域不同
end


function downMp3(id)
   
    local url="http://www.ximalaya.com/tracks/"..id..".json"
    local mp3 = "http://fdfs.xmcdn.com/"
    local ok,html = get_html(url)
    if ok then
        local result = json.decode(html)
        print(mp3..result.play_path_64)
    else
        print("error")
    end
end
if arg[1] and tonumber(arg[1]) then
    downMp3(arg[1])
else
    print("请输入编号")
end