示例：使用cat命令查看/etc/issue，再使用tac命令查看/etc/issue
[root@node1 ~]# cat /etc/issue \S Kernel \r on an \m [root@node1 ~]# tac /etc/issue Kernel \r on an \m \S
Linux命令（34）tac命令
原文：https://www.cnblogs.com/shijunxian/p/12984670.html
