程序的互斥运行 如果你的程序被同时运行两次以上，有可能会造成文件系统冲突而丢失数据，本例程用一个简单的办法避免第二次启动同一个程序。-operating procedures contradict the procedure if you are running two or more, and may cause conflicts and file system data loss, the routines with a simple way to avoid the second s