lua utf8 gbk 编码转换

lua的utf8互转gbk编码方法, 基于linux下实现，使用lua-iconv的.

安装：
luarocks install lua-iconv

安装过程感觉有点慢，那个lua-iconv网址有时获取不到，不行的时候就再尝试下吧.

然后以下就是转换代码：

local iconv = require("iconv")http=require("socket.http")function createIconv(from,to,text)    local cd = iconv.new(to .. "//TRANSLIT", from)  local ostr, err = cd:iconv(text)  if err == iconv.ERROR_INCOMPLETE then    return "ERROR: Incomplete input."  elseif err == iconv.ERROR_INVALID then    return "ERROR: Invalid input."  elseif err == iconv.ERROR_NO_MEMORY then    return "ERROR: Failed to allocate memory."  elseif err == iconv.ERROR_UNKNOWN then    return "ERROR: There was an unknown error."  end  return ostrendresult=http.request("http://www.lpfrx.com")print(createIconv("utf-8","gbk",result))