作为一名运维工程师，经常会部署各种用途的操作系统，但在这些工作中，我们会发现很多工作其实是重复性的劳动，操作的内容也是大同小异，基于这类情况，我们可以把相同的操作做成统一执行的脚本，不同的东西作为变量手动输入。节约下来的时间不就可以做更多有意义的事情吗？

最近在粉丝有推荐下发现一款比较好用的shell源码，也基于此改编了一下，分享给大家：

主菜单：

二级菜单：

主要实现系统的各类优化，比如常用的修改字符集、关闭selinux、关闭防火墙、安装常用工具和加快ssh登录等功能。

源码如下：

#!/bin/sh. /etc/rc.d/init.d/functionsexport LANG=zh_CN.UTF-8#一级菜单menu1(){        clear        cat <<EOF----------------------------------------|****   欢迎使用cetnos7.9优化脚本    ****||****      博客地址: aaa.al         ****|----------------------------------------1. 一键优化2. 自定义优化3. 退出EOF        read -p "please enter your choice[1-3]:" num1}#二级菜单menu2(){ clear cat <<EOF----------------------------------------|****Please Enter Your Choice:[0-13]****|----------------------------------------1. 修改字符集2. 关闭selinux3. 关闭firewalld4. 精简开机启动5. 修改文件描述符6. 安装常用工具及修改yum源7. 优化系统内核8. 加快ssh登录速度9. 禁用ctrl+alt+del重启10.设置时间同步11.history优化12.返回上级菜单13.退出EOF read -p "please enter your choice[1-13]:" num2 }#1.修改字符集localeset(){ echo "========================修改字符集=========================" cat > /etc/locale.conf <<EOFLANG="zh_CN.UTF-8"#LANG="en_US.UTF-8"SYSFONT="latarcyrheb-sun16"EOF source /etc/locale.conf echo "#cat /etc/locale.conf" cat /etc/locale.conf action "完成修改字符集" /bin/true echo "===========================================================" sleep 2}#2.关闭selinuxselinuxset() { selinux_status=`grep "SELINUX=disabled" /etc/sysconfig/selinux | wc -l` echo "========================禁用SELINUX========================" if [ $selinux_status -eq 0 ];then  sed  -i "s#SELINUX=enforcing#SELINUX=disabled#g" /etc/sysconfig/selinux  setenforce 0  echo '#grep SELINUX=disabled /etc/sysconfig/selinux'  grep SELINUX=disabled /etc/sysconfig/selinux  echo '#getenforce'  getenforce else  echo 'SELINUX已处于关闭状态'  echo '#grep SELINUX=disabled /etc/sysconfig/selinux'                grep SELINUX=disabled /etc/sysconfig/selinux                echo '#getenforce'                getenforce fi  action "完成禁用SELINUX" /bin/true echo "===========================================================" sleep 2}#3.关闭firewalldfirewalldset(){ echo "=======================禁用firewalld========================" systemctl stop firewalld.service &> /dev/null echo '#firewall-cmd  --state' firewall-cmd  --state systemctl disable firewalld.service &> /dev/null echo '#systemctl list-unit-files | grep firewalld' systemctl list-unit-files | grep firewalld action "完成禁用firewalld，生产环境下建议启用！" /bin/true echo "===========================================================" sleep 5}#4.精简开机启动chkset(){ echo "=======================精简开机启动========================" systemctl disable auditd.service systemctl disable postfix.service systemctl disable dbus-org.freedesktop.NetworkManager.service echo '#systemctl list-unit-files | grep -E "auditd|postfix|dbus-org\.freedesktop\.NetworkManager"' systemctl list-unit-files | grep -E "auditd|postfix|dbus-org\.freedesktop\.NetworkManager" action "完成精简开机启动" /bin/true echo "===========================================================" sleep 2}#5.修改文件描述符limitset(){ echo "======================修改文件描述符=======================" echo '* - nofile 65535'>/etc/security/limits.conf ulimit -SHn 65535 echo "#cat /etc/security/limits.conf" cat /etc/security/limits.conf echo "#ulimit -Sn ; ulimit -Hn" ulimit -Sn ; ulimit -Hn action "完成修改文件描述符" /bin/true echo "===========================================================" sleep 2}#6.安装常用工具及修改yum源yumset(){ echo "=================安装常用工具及修改yum源===================" yum install wget -y &> /dev/null if [ $? -eq 0 ];then  cd /etc/yum.repos.d/  \cp CentOS-Base.repo CentOS-Base.repo.$(date +%F)  ping -c 1 mirrors.aliyun.com &> /dev/null  if [ $? -eq 0 ];then   wget -O /etc/yum.repos.d/CentOS-Base.repo  &> /dev/null   yum clean all &> /dev/null   yum makecache &> /dev/null  else   echo "无法连接网络"       exit $?    fi else  echo "wget安装失败"  exit $? fi yum -y install ntpdate lsof net-tools telnet vim lrzsz tree nmap nc sysstat &> /dev/null action "完成安装常用工具及修改yum源" /bin/true echo "===========================================================" sleep 2}#7. 优化系统内核kernelset(){ echo "======================优化系统内核=========================" chk_nf=`cat /etc/sysctl.conf | grep conntrack |wc -l` if [ $chk_nf -eq 0 ];then  cat >>/etc/sysctl.conf<<EOFnet.ipv4.tcp_fin_timeout = 2net.ipv4.tcp_tw_reuse = 1net.ipv4.tcp_tw_recycle = 1net.ipv4.tcp_syncookies = 1net.ipv4.tcp_keepalive_time = 600net.ipv4.ip_local_port_range = 4000 65000net.ipv4.tcp_max_syn_backlog = 16384net.ipv4.tcp_max_tw_buckets = 36000net.ipv4.route.gc_timeout = 100net.ipv4.tcp_syn_retries = 1net.ipv4.tcp_synack_retries = 0net.core.somaxconn = 16384net.core.netdev_max_backlog = 16384net.ipv4.tcp_max_orphans = 16384net.netfilter.nf_conntrack_max = 25000000net.netfilter.nf_conntrack_tcp_timeout_established = 180net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120EOF sysctl -p else  echo "优化项已存在。" fi action "内核调优完成" /bin/true echo "===========================================================" sleep 2}#8.加快ssh登录速度sshset(){ echo "======================加快ssh登录速度======================" sed -i 's#^GSSAPIAuthentication yes$#GSSAPIAuthentication no#g' /etc/ssh/sshd_config sed -i 's/#UseDNS yes/UseDNS no/g' /etc/ssh/sshd_config systemctl restart sshd.service echo "#grep GSSAPIAuthentication /etc/ssh/sshd_config" grep GSSAPIAuthentication /etc/ssh/sshd_config echo "#grep UseDNS /etc/ssh/sshd_config" grep UseDNS /etc/ssh/sshd_config action "完成加快ssh登录速度" /bin/true echo "===========================================================" sleep 2}#9. 禁用ctrl+alt+del重启restartset(){ echo "===================禁用ctrl+alt+del重启====================" rm -rf /usr/lib/systemd/system/ctrl-alt-del.target action "完成禁用ctrl+alt+del重启" /bin/true echo "===========================================================" sleep 2}#10. 设置时间同步ntpdateset(){ echo "=======================设置时间同步========================" yum -y install ntpdate &> /dev/null if [ $? -eq 0 ];then  /usr/sbin/ntpdate time.windows.com  echo "*/5 * * * * /usr/sbin/ntpdate ntp.aliyun.com &>/dev/null" >> /var/spool/cron/root else  echo "ntpdate安装失败"  exit $? fi action "完成设置时间同步" /bin/true echo "===========================================================" sleep 2}#11. history优化historyset(){ echo "========================history优化========================" chk_his=`cat /etc/profile | grep HISTTIMEFORMAT |wc -l` if [ $chk_his -eq 0 ];then  cat >> /etc/profile <<'EOF'#设置history格式export HISTTIMEFORMAT="[%Y-%m-%d %H:%M:%S] [`whoami`] [`who am i|awk '{print $NF}'|sed -r 's#[()]##g'`]: "#记录shell执行的每一条命令export PROMPT_COMMAND='\if [ -z "$OLD_PWD" ];then    export OLD_PWD=$PWD;fi;if [ ! -z "$LAST_CMD" ] && [ "$(history 1)" != "$LAST_CMD" ]; then    logger -t `whoami`_shell_dir "[$OLD_PWD]$(history 1)";fi;export LAST_CMD="$(history 1)";export OLD_PWD=$PWD;'EOF  source /etc/profile else  echo "优化项已存在。" fi action "完成history优化" /bin/true echo "===========================================================" sleep 2}#控制函数main(){ menu1 case $num1 in  1)   localeset   selinuxset   firewalldset   chkset   limitset   yumset   kernelset   sshset   restartset   ntpdateset   historyset   ;;  2)   menu2   case $num2 in                  1)                    localeset                    ;;                  2)                    selinuxset                    ;;                  3)                    firewalldset                    ;;                  4)                    chkset                    ;;                  5)                    limitset                    ;;                  6)                 yumset                    ;;                  7)                    kernelset                    ;;                  8)                    sshset                    ;;                  9)                    restartset                    ;;                  10)                    ntpdateset                    ;;    11)      historyset      ;;    12)      main      ;;    13)      exit      ;;    *)      echo 'Please select a number from [1-13].'      ;;   esac   ;;  3)   exit   ;;  *)   echo 'Err:Please select a number from [1-3].'   sleep 3   main   ;; esac}main $*

将其保存为init.sh，然后赋予执行权限后执行即可。

chmod +x init.sh && ./init.sh

如果这样来回地复制粘贴很麻烦，也可以通过我的一键命令执行，同样能达到上面的效果：

bash -c "$(curl -L s.aaa.al/init.sh)"

最后，如果大家有想实现的功能，也可以在原有脚本的基础上进行修改实现。