lua 删除txt文本最后一行

local file = io.open('2.txt', "r+")local content = file:read("*all")local t = string.gmatch(content, "([^\n]+)[\n]*$")()local content_len = string.len(content)local t_len = string.len(t)file:close()local str = string.sub(content, 0, content_len-t_len-1)file = io.open('2.txt', 'w')file:write(str)file:close()