Linux 系统连接之前与之后显示

1、/etc/motd       登录系统之后显示的信息
#vim /etc/motd  
==> welcome to redhat study
                            _ooOoo_
                           o8888888o
                           88" . "88
                           (| -_- |)
                            O\ = /O
                        ____/`---'\____
                      .   ' \\| |// `.
                       / \\||| : |||// \
                     / _||||| -:- |||||- \
                       | | \\\ - /// | |
                     | \_| ''\---/'' | |
                      \ .-\__ `-` ___/-. /
                   ___`. .' /--.--\ `. . __
                ."" '< `.___\_<|>_/___.' >'"".
               | | : `- \`.;`\ _ /`;.`/ - ` : | |
                 \ \ `-. \_ __\ /__ _/ .-` / /
         ======`-.____`-.___\_____/___.-`____.-'======
                            `=---='
 
2、/etc/issue    文件内容会在连接系统之前显示