首页 > 代码库 > /etc/issue 与 /etc/issue.net 文件,telnet登陆前的显示

/etc/issue 与 /etc/issue.net 文件,telnet登陆前的显示

  • 若是通过本地文本设备(如本地终端,本地虚拟控制台等)登录,则该信息存放与/etc/issue文件中;
  • 若是通过远程本文设备(如通过ssh或telnet等)登录,则该信息存放与/etc/issue.net文件中。

1. 第一映像:

unimous@unimous-f41:~$ cat /etc/issue
Ubuntu 11.10 \n \l

unimous@unimous-f41:~$ cat /etc/issue.net
Ubuntu 11.10

2. \n \l 是什么?

在/etc/issue文件中,允许使用转义序列(escape sequence),当系统遇到escape sequence的时候会自动替换成相应的信息,比如:\n代表主机名。完整的转移序列列表如下(此列表摘自:man agetty,因为此issue由agetty负责解释):

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. u    Insert the number of current users logged in. U    Insert  the string "1 user" or "<n> users" where <n> is the number of current users logged in. v    Insert the version of the OS, eg. the build-date etc.

3. 关于issue.net的说明:

首先,issue.net中不能存在escape sequence;

其次,使用ssh登录时,会不会显示issue信息由ssh的配置决定。

/etc/issue 与 /etc/issue.net 文件,telnet登陆前的显示