所有用户执行的命令实时保存在一个文件中,文件内容如下:2016-03-0117:34:42#####USER:rootIP:172.16.50.146816022PS:/dev/pts/1ppid=2037pwd=/root####wgethttp://mirror.bit.edu.cn/apache/hadoop/common/hadoop-2.6.0/hadoop-2.6.0.tar.gz2016-03-0117:35:23#####USER:rootIP:172.16.50.146807722PS:/dev/pts/0ppid=1993pwd=/home####./etc/profile2016