咸鱼今天给大家分享一个无论是学习还是工作中都很实用的 Linux 系统初始化脚本，其实就是各种命令的集合

 

完整代码在文章最后哦

 

定义相关变量

 

 

 

配置 yum 镜像源

 

 

获取阿里云 yum 镜像源

 

 

判断函数是否执行成功

 

 

写入一行配置

 

 

修改配置

 

 

配置系统时区

 

 

配置 dns 服务器

 

 

修改最大文件描述符限制

 

 

关闭系统不需要的服务

 

 

内核参数优化相关

 

 

安装常用工具

 

 

关闭 SELinux

 

 

主函数

 

 

完整脚本

#环境变量
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin
export PATH

#当前时间
current_time=$(date +%Y%m%d)

#阿里的DNS
dns_server=223.5.5.5 

if [[ ! -z `uname -r|grep 'el6'` ]]
  then
  kernel_version=el6
  yum_repo=http://mirrors.aliyun.com/repo/Centos-6.repo
elif [[ ! -z `uname -r|grep 'el7'` ]]
  then
  kernel_version=el7
  yum_repo=http://mirrors.aliyun.com/repo/Centos-7.repo
else
  echo -e "\e[31mUnidentified Kernel version: $(uname -r). Only support for kernel el6/el7\e[0m"
  exit
fi

function add_yum_repo(){
  local item="Add Aliyun Yum Mirrors"
  yum clean all
  cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.${current_time} && \
  curl -o /etc/yum.repos.d/CentOS-Base.repo ${yum_repo} > /dev/null 2>&1
  show_result $? "${item}"
  yum makecache
}

function show_result(){
  if [ "$1" -eq 0 ]
    then
      echo -e "\e[32m$2 is Success .   [ OK ] \e[0m"
    else
      echo -e "\e[31m$2 is Fail .   [ FAIL ] \e[0m"
  fi
}

function add_newconfig_tofile(){
  local SearchResult=`grep "$1" "$2"`
  if [ -z "${SearchResult}" ]
    then
    echo "$1" >> $2
  fi
}

function add_config_tofile(){
  local keywords=`echo $1| awk -F "[= ]+" '{print $1}'`
  local SearchResult=`grep "^${keywords}" "$2"`
  if [ -z "${SearchResult}" ] #空为真，非空为假
    then
    echo $1 >> $2
  else
    sed -i "s/^${keywords}.*/$1/" $2
  fi
}

function config_localtime(){
  local item="Config SH As Location"
  rm -f /etc/localtime
  ln -s  /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
  show_result $? "${item}"
}

function config_dns_addr(){
  local item="Config DNS Address"
  cp /etc/resolv.conf /etc/resolv.conf.${current_time} && \
  echo "nameserver ${dns_server}" > /etc/resolv.conf
  show_result $? "${item}"
}

function maximum_file_dspt(){
  local item="Maximum File Descriptor"
  cp /etc/security/limits.conf /etc/security/limits.conf.${current_time} && \
  echo "*           soft    nofile          100000
*           hard    nofile          100000
*           soft    nproc           65535
*           hard    nproc           65535
*           soft    core            unlimited
*           hard    core            unlimited" > /etc/security/limits.conf
  show_result $? "${item}"
}


function shutdown_nonuse_srv(){
  local item="Shutdown Unused Services"
  if [[ "${kernel_version}" == el6 ]]
      then
    for i in `chkconfig --list | awk '{print $1}'`
      do
      chkconfig --level 2345 $i off > /dev/null 2>&1
      done
    for ii in crond network rsyslog sshd sysstat haldaemon
      do
      chkconfig --level 2345 $ii on > /dev/null 2>&1
      done
    show_result $? "${item}"
  elif [[ "${kernel_version}" == el7 ]]
    then
    systemctl disable postfix > /dev/null 2>&1
    show_result $? "${item}"
  else