修改Linux登录欢迎提示信息

之前登陆某服务器，见到了花式的欢迎信息，然后，就很想试试~

服务器一般可以配置两种类型的提示信息：①用户登录前显示的提示信息；②用户成功登录后显示的提示信息。需注意的是，不同的linux发行版本修改的方法不太一样。

大致过程如下：

(1) 查看服务器的基本信息

uname -a #查看服务器的基本信息

可以看到，是熟悉的Ubuntu~

(2) 修改登录欢迎信息

在一般的linux发行版中（如centos），/etc/issue里存放了用户成功登录前显示的信息；/etc/motd存放了用户成功登录后显示的信息；但在Ubuntu中，相关的是/etc/update-motd.d/文件夹下的几个脚本：

cd /etc/update-motd.d/ls -alF

通过ssh登录主机/服务器时，会输出/var/run/motd.dynamic 中的信息。而/var/run/motd.dynamic 中的信息就是用户登录时系统已root身份执行上述/etc/update-motd.d/ 下面的几个脚本所生成的。所以想要DIY欢迎信息，就需要修改这几个脚本文件。

cat /var/run/motd.dynamic #查看当前的登录提示语

修改前的提示语，嗯，还蛮老干部的，为了留个纪念，我决定给备个份，毕竟之后就看不到了。值得注意的是，修改系统配置文件要谨慎。

sudo cp /var/run/motd.dynamic{,.bak} #生成备份文件motd.dynamic.bak

结合脚本文件的名字和提示语的各部分内容，可以大致推断出需作出的修改。其中，00-header主要是显示一些欢迎信息的头部；10-help-text中主要是一些提供帮助查询网站的信息。其它还有一些软件包更新、系统更新等信息，本文主要以前两个脚本文件为例。

查看00-header脚本文件：

cat /etc/update-motd.d/00-header#!/bin/sh## 00-header - create the header of the MOTD# Copyright (C) 2009-2010 Canonical Ltd.## Authors: Dustin Kirkland <[e-mail]>## This program is free software; you can redistribute it and/or modify# it under the terms of the GNU General Public License as published by# the Free Software Foundation; either version 2 of the License, or# (at your option) any later version.## This program is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU General Public License for more details.## You should have received a copy of the GNU General Public License along# with this program; if not, write to the Free Software Foundation, Inc.,# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.[ -r /etc/lsb-release ] && . /etc/lsb-releaseif [ -z "$DISTRIB_DESCRIPTION" ] && [ -x /usr/bin/lsb_release ]; then # Fall back to using the very slow lsb_release utility DISTRIB_DESCRIPTION=$(lsb_release -s -d)fiprintf "Welcome to %s (%s %s %s)\n" "$DISTRIB_DESCRIPTION" "$(uname -o)" "$(uname -r)" "$(uname -m)"


查看10-help-text文件：

cat /etc/update-motd.d/10-help-text#!/bin/sh## 10-help-text - print the help text associated with the distro# Copyright (C) 2009-2010 Canonical Ltd.## Authors: Dustin Kirkland <[e-mail]>,# Brian Murray <[e-mail]>## This program is free software; you can redistribute it and/or modify# it under the terms of the GNU General Public License as published by# the Free Software Foundation; either version 2 of the License, or# (at your option) any later version.## This program is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU General Public License for more details.## You should have received a copy of the GNU General Public License along# with this program; if not, write to the Free Software Foundation, Inc.,# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
printf "\n"printf " * Documentation: https://help.ubuntu.com\n"printf " * Management: https://landscape.canonical.com\n"printf " * Support: https://ubuntu.com/advantage\n"


大致了解脚本文件长什么样子了，就可以开始修改了。其实，主要修改00-header脚本文件就可以啦，帮助文件10-help-text的4行内容直接注释掉就好了，没必要展示。

#为防止改崩了或者改丑了，先给这些系统文件创建备份sudo cp /etc/update-motd.d/00-header{,.bak}sudo cp /etc/update-motd.d/10-help-text{,.bak}
sudo vim /etc/update-motd.d/10-help-text #修改10-help-text脚本文件sudo vim /etc/update-motd.d/00-header #修改00-header脚本文件
#!/bin/sh## 00-header - create the header of the MOTD# Copyright (C) 2009-2010 Canonical Ltd.## Authors: Dustin Kirkland <[e-mail]>## This program is free software; you can redistribute it and/or modify# it under the terms of the GNU General Public License as published by# the Free Software Foundation; either version 2 of the License, or# (at your option) any later version.## This program is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU General Public License for more details.## You should have received a copy of the GNU General Public License along# with this program; if not, write to the Free Software Foundation, Inc.,# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
[ -r /etc/lsb-release ] && . /etc/lsb-release
if [ -z "$DISTRIB_DESCRIPTION" ] && [ -x /usr/bin/lsb_release ]; then # Fall back to using the very slow lsb_release utility DISTRIB_DESCRIPTION=$(lsb_release -s -d)fiprintf "Welcome to %s (%s %s %s)\n" "$DISTRIB_DESCRIPTION" "$(uname -o)" "$(uname -r)" "$(uname -m)"printf "\n"printf "########################## Softwares installed #############################"printf "\n# `ls /home/hucy/.soft | sort | paste -s -d / `\n"printf "############################################################################"


本例仅简单增加了4行，目的是在登录成功后，显示已安装的软件。注：/home/hucy/.soft目录下，是给所有安装成功的软件创建的软链接。

修改后，登录成功后的界面如下：

修改后的界面比较丑，但是基本达到了目的。总归是别人家的服务器，就改到这里吧~

参考阅读：

1. CentOS查看系统信息命令和方法 https://www.cnblogs.com/kluan/p/4457889.html

2. 教你如何修改Linux远程登录欢迎提示信息 https://www.jb51.net/article/136267.htm

3. Ubuntu修改ssh登录欢迎信息 https://blog.csdn.net/plm199513100/article/details/81270377