监控指定文件夹，当文件夹内的任何一个文件发生修改时，就会读取指定的.txt文件的倒数第四行的内容。如果在这个文件夹内只存放一个txt日志文件，则该程序可变成一个监控日志更新的程序。-Monitor specified folder, any folder when a file changes occur, they will read a specified. Txt file contents of the fourth line last. In this folder, if only a txt log file storage, then the procedure could become a surveillance log update procedure.