未登入时提示信息设置
一、添加rc-local.service服务脚本
创建/etc/systemd/system/rc-local.service服务脚本 运行下述命令，生成服务脚本
cat > /etc/systemd/system/rc-local.service << EOF
[Unit]
Description=/etc/rc.local Compatibility
ConditionFileIsExecutable=/etc/rc.local
After=network.target
[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
GuessMainPID=no
[Install]
WantedBy=multi-user.target
Alias=rc-local.service
EOF二、创建rc.local脚本
cat > /etc/rc.local << EOF
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
exit 0
EOF三、赋予rc.local可执行权限
chmod +x /etc/rc.local四、添加自启脚本或命令并测试创建欢迎信息的shell脚本并赋予执行权限
将所需要执行的命令或脚本写入exit 0之前即可，如：
cd ~&&touch OSInfo.sh&&chmod +x OSInfo.sh五、将以下代码写入到OSInfo.sh
根据需求修改显示内容
vim OSInfo.sh#!/bin/bash
# 清空issue
echo "" > /etc/issue
echo "" > /etc/motd
# 获取所有网卡名称及IP地址，不去掉子网掩码
#ip=`ip addr | grep inet | grep -v inet6 | awk '{print("\033[34m|\033[0m\033[32m",$NF,"\t->",$2,"\033[0m")}'`
# 获取所有网卡名称及ip地址，去掉子网掩码
#ip=`ip addr | grep inet | awk '{print("\033[34m|\033[0m\033[32m",$NF,"\t->",$2,"\033[0m")}' | sed 's/host//g' | sed 's/noprefixroute//g' | sed 's/link//g'`
# 间隔符
t1="\033[34m+----------------------------\033[0m"
t2="\033[34m|\033[0m\033[32m"
t3="\033[0m"
#********************下方是开机提示信息********************#
echo "" >> /etc/issue
echo -e "$t1" >> /etc/issue
echo -e "$t2 Debian v11.6.0 $t3" >> /etc/issue
echo -e "$t1" >> /etc/issue
echo -e "$t2 UserName -> root $t3" >> /etc/issue
echo -e "$t2 PassWord -> Test@123 $t3" >> /etc/issue
echo -e "$t1" >> /etc/issue
echo -e "$t2 NetWork $t3" >> /etc/issue
echo -e "$ip" >> /etc/issue
echo -e "$t1" >> /etc/issue
echo "" >> /etc/issue
#********************下方是登入欢迎信息********************#
echo "The programs included with the Debian GNU/Linux system are free software;" >> /etc/motd
echo "the exact distribution terms for each program are described in the" >> /etc/motd
echo "individual files in /usr/share/doc/*/copyright." >> /etc/motd
echo "" >> /etc/motd
echo "Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent" >> /etc/motd
echo "permitted by applicable law." >> /etc/motd
echo "" >> /etc/motd
echo -e "$t1" >> /etc/motd
echo -e "$t2 Debian v11.6.0 $t3" >> /etc/motd
echo -e "$t1" >> /etc/motd
echo -e "$t2 UserName -> root $t3" >> /etc/motd
echo -e "$t2 PassWord -> Test@123 $t3" >> /etc/motd
echo -e "$t1" >> /etc/motd
echo -e "$t2 NetWork $t3" >> /etc/motd
echo -e "$ip" >> /etc/motd
echo -e "$t1" >> /etc/motd
echo "" >> /etc/motd六、添加自启脚本或命令并测试
将所需要执行的命令或脚本写入exit 0之前即可，如：
vim /etc/rc.local#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
bash /root/OSInfo.sh
exit 0登入后欢迎信息设置
进入“/etc/update-motd.d”路径下。
cd /etc/update-motd.d创建“99-welcome-info”文件。
touch 99-welcome-info将以下代码写入到“99-welcome-info”文件中。
vim 99-welcome-info#!/bin/bash
# 获取所有网卡名称及IP地址，不去掉子网掩码
ip=`ip addr | grep inet | grep -v inet6 | awk '{print("\033[34m|\033[0m\033[32m",$NF,"\t->",$2,"\033[0m")}'`
# 间隔符
t1="\033[34m+----------------------------\033[0m"
t2="\033[34m|\033[0m\033[32m"
t3="\033[0m"
#********************下方是登入欢迎信息********************#
printf "\n"
printf "$t1\n"
printf "$t2 Ubuntu 22.04.3 LTS $t3\n"
printf "$t1\n"
printf "$t2 UserName: root $t3\n"
printf "$t2 PassWord: Test@123 $t3\n"
printf "$t1\n"
printf "$t2 NetWork $t3\n"
printf "$ip\n"
printf "$t1\n"给“99-welcome-info”添加执行权限。
sudo chmod 755 99-welcome-info4.脚本添加到rc.local中
vim /etc/rc.d/rc.local将“/root/hello.sh”添加到rc.local的末尾
/root/OsInfo.sh5.使用Systemd服务
在最新版本的CentOS（如CentOS 7及更高版本）中，/etc/rc.local文件不再默认存在，因此不再是系统启动时执行自定义脚本的推荐方式。取而代之的是使用Systemd服务单元或Cron作业来执行自定义脚本。以下是一些替代方案： Systemd是现代Linux发行版中常用的初始化系统，您可以创建一个Systemd服务单元，以在系统启动时执行自定义脚本。以下是一个示例： 1. 创建一个Systemd服务单元文件（例如，/etc/systemd/system/my-custom-script.service），并使用文本编辑器打开它：
sudo nano /etc/systemd/system/my-custom-script.service**2. 在该文件中定义您的自定义脚本服务单元。例如：**
```shell
[Unit]
Description=My Custom Script
[Service]
Type=oneshot
ExecStart=/path/to/your/script.sh
[Install]
WantedBy=multi-user.target其中，ExecStart行指定要执行的脚本的路径。 3. 保存并关闭文件。 4. 启用并启动Systemd服务：
sudo systemctl enable my-custom-script
sudo systemctl start my-custom-script这将使您的脚本在系统引导时自动运行。