成功登录系统后有一些消息显示。
例如（如果系统运行的是 Ubuntu）

"The programs included with the Ubuntu system are free software; the 
exact distribution terms for each program are described in the 
individual files in /usr/share/doc/*/copyright.
Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted 
by applicable law.
To access official Ubuntu documentation, please visit: 
http://help.ubuntu.com/"

该消息称为“今日消息”，又名 motd。
它是 /etc/motd 中的文本文件存储，但在 Linux 上被替换为 /etc/motd.tail 中的副本。
使用 vi 或者我们选择的其他编辑器使用我们想要的消息更改文件。

以下是一些转义码以显示一些添加信息：

\b = Insert the baudrate of the current line.
\d = Insert the current date.
\s = Insert the system name, the name of the operating system.
\l = Insert the name of the current tty line.
\m = Insert the architecture identifier of the machine, eg. i486
\n = Insert  the nodename of the machine, also known as the hostname.
\o = Insert the NIS domainname of the machine.
\O = Insert the DNS domainname of the machine.
\r = Insert the release number of the OS, eg. 1.1.9.
\t = Insert the current time.
_= Insert the number of current users logged in.
_= Insert the string "1 user" or "<n> users" where <n> is the number
of users login.