解决nginx+lua搭建文件上传下载服务问题

export LUAJIT_LIB=/usr/local/luajit/lib 
export LUAJIT_INC=/usr/local/luajit/include/luajit-2.0 
./configure --prefix=/usr/local/nginx --with-http_stub_status_module --with-http_ssl_module --add-module=/home/oicq/jeffzhuang/ngx_devel_kit-0.3.0 --add-module=/home/oicq/jeffzhuang/lua-nginx-module-0.10.
make -j2 
make install

--文件下载服务写到 saveRootPath .."/" .. filename 下面 
function DownLoad()
 local chunk_size = 4096
 local form,err=upload:new(chunk_size)
 if not form then
  ngx.log(ngx.ERR, "failed to new upload: ", err)
  ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
 end 
 form:set_timeout(100000)
 while true do
 local typ,res,err=form:read()
 if not typ then
  ErrorMsg="failed to read :"..err
  return 1
 end
 if typ =="header" then
  local key=res[1]
  local value=res[2]
  if key =="Content-Disposition" then
  local kvlist=string.split(value,';')
   for _, kv in ipairs(kvlist) do
   local seg = string.trim(kv)
   if seg:find("filename") then
   local kvfile = string.split(seg, "=")
   filename = string.sub(kvfile[2], 2, -2)
   if filename then
    --获取文件后缀名字
    fileExtension=getExtension(filename)
    local linuxTime=tostring(os.time())
    filePath=saveRootPath .."/" ..linuxTime..filename
    fileToSave,errmsg = io.open(filePath, "w+")
    --存储的文件路径   
    --ngx.say("failed to open file ", filePath)
    if not fileToSave then
    --ngx.say("failed to open file ", filePath .. errmsg)
    ErrorMsg="打开文件失败"..filePath .. errmsg
    return 1
    end
   else
    ErrorMsg="请求参数找不到文件名字"
    return 1
   end
   --跳出循环
   break 
   end
   end
  end
 elseif typ =="body" then
  if fileToSave then
  fileToSave:write(res)
  fileMd5:update(res)
  end
 elseif typ =="part_end" then
  if fileToSave then
  local md5_sum=fileMd5:final()
  --ngx.say("md5: ", str.to_hex(md5_sum))
  fileMD532=str.to_hex(md5_sum)
  fileToSave:close()
  fileToSave = nil
  end  
 elseif typ =="eof" then
  break
 else
  ngx.log(ngx.INFO, "do other things")
 end
 end
 return 0
end

-- 读取byte
function readInt8(tcp)
 local next, val = string.unpack(tcp:receive(1), "b")
 return tonumber(val);
end
-- 读取int16
function readInt16(tcp)
 local next, val = string.unpack(tcp:receive(2), "h");
 return tonumber(val);
end
-- 读取int32
function readInt32(tcp)
 local next, val = string.unpack(tcp:receive(4), ">i");
 return tonumber(val);
end
-- 读取字符串
function readString(tcp,len)
 return tostring(tcp:receive(len));
end

jsonData["filename"]=fileMD532 .. "." .. fileExtension
jsonData["cmd"]="write"
jsonData["fileSize"]=tostring(filelen)
jsonData["path"]=System.."/"..StorageDate
local Jsonstr=cjson.encode(jsonData)
local uiLen=string.len(Jsonstr)
senddata=bpack(">b1IAb",startIndex,uiLen,Jsonstr,endIndex)
socket:send(senddata)

local ErrorUrl="/downloadError.html"
ErrorMsg="url 参数解析有问题 "..index
return ngx.redirect(ErrorUrl.."?msg="..ErrorMsg,``` ngx.HTTP_MOVED_TEMPORARILY)