var file = assert(io.open("C:\Users\Administrator\Desktop\a.txt",'r'),"打开失败")
//w不设置写入方式，若w,ccs=UTF-8将出错
//r+不清除原先的内容，直接覆盖
//往文件里写u8编码就是u8，写gbk编码就是gbk

io.open()
io.print(string.fromto(file.read(),,936 ) )//读取utf-8编码文件内容，并转成gbk输出
io.close()
file.close()