Linux清理大师：一键优化你的系统

#!/bin/bash

# 关闭不必要的服务
systemctl stop bluetooth
systemctl disable bluetooth
systemctl stop cups
systemctl disable cups

# 更新系统
sudo apt update && sudo apt upgrade -y

# 清理无用软件包
sudo apt autoremove -y
sudo apt clean

# 关闭IPv6
echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf
echo "net.ipv6.conf.default.disable_ipv6 = 1" >> /etc/sysctl.conf
sudo sysctl -p

# 调整系统内核参数
echo "vm.swappiness = 10" >> /etc/sysctl.conf
echo "net.ipv4.tcp_syncookies = 1" >> /etc/sysctl.conf
echo "net.ipv4.tcp_fin_timeout = 30" >> /etc/sysctl.conf
sudo sysctl -p

# 安装常用工具
sudo apt install -y vim wget curl net-tools

# 设置SSH登录提示信息
echo "Welcome to My Linux System" > /etc/issue
echo "This system is for authorized use only" >> /etc/issue
echo "All activity may be monitored and reported" >> /etc/issue

# 设置系统DNS解析服务器
echo "nameserver 8.8.8.8" > /etc/resolv.conf

# 关闭root用户SSH登录
echo "PermitRootLogin no" >> /etc/ssh/sshd_config
sudo systemctl restart sshd

# 设置系统时区
sudo timedatectl set-timezone Asia/Shanghai

# 安装和配置防火墙
sudo apt install -y firewalld
sudo systemctl enable firewalld
sudo systemctl start firewalld
sudo firewall-cmd --zone=public --add-service=ssh --permanent
sudo firewall-cmd -reload

请注意，在进行任何系统更改之前，建议备份重要数据，并确保了解每个命令和工具的作用。