#! /bin/bash

Determine whether a current user is a root user, or if it is not, you will be prompted to use sudo to elevate permissions

if [ $user != "root"]

then

echo "Scripts that require sudo to use"]

exit 1

Set Selinux to off

sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config

Download a CentOS yum source

cd /usr/local/src

wget http://mirrors.163.com/.help/CentOS6-Base-163.repo

Backup the previous yum source

cd /etc/yum.repo.d/

mv CentOS-Base.repo CentOS-Base.repo.bak

Copy the yum source just downloaded to the /etc/yum.repo.d/ directory

cp /usr/local/src/CentOS6-Base-163.repo ./CentOS-Base.repo

yum clean all #Clear cache information

yum makecache #Regenerate the cache

yum update -y #Upgrade the system and its installation package

Add epel external yum source

cd /usr/local/src

wget http://d1.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

rpm -ivh epel-release-6-8.noarch.rpm

Install gcc basic library files and sysstat tool

sysstat is a software package that includes a set of tools for testing system performance and efficiency.

yum -y install gcc gcc-c++ vim-enhanced unzip unrar sysstat

yum install -y setuptool setup's main toolkit

yum install -y system-config-network-tui setup supporting network card setup toolkit

yum install -y iptables system-config-securitylevel-tui setup supporting firewall toolkit

yum install --y bash-completion-20090212-1mdv2009.1.noarch command completion toolkit

yum install --y tree.x86_64 tree display directory structure

Configure ntpdate automatic time synchronization

yum -y install ntp

echo "01 01 * * * /usr/sbin/ntpdate ntp.api.bz >> /dev/null 2>&1" >> /etc/crontab

/usr/sbin/ntpdate ntp.api.bz

service crond restart

for i in chkconfig --list | grep 3:on |awk -F " " '{print $1}'

/sbin/chkconfig --level 3 $i off

done

for a in {crond,network,rsyslog,sshd,sysstat}

/sbin/chkconfig --level 3 $a on

done

Personalized vim settings

cat >>/root/.vimrc<<EOF

set number #display with line number

set ruler

set nohlsearch

set shiftwidth=2

set tabstop=4 #tab is 4 spaces

set expandtab

set cindent

set autoindent #Automatic alignment

set mouse=v

syntax on

EOF

Hide linux information

echo “” > /etc/issue

This is a historical command

echo "export HISTSIZE=500" >>/etc/profile

echo “export HISTFILE=/dev/null” >>/etc/profile

echo “export HISTFILESIZE=50” >> /etc/profile

echo “export TIMEOUT=300” >>/etc/profile

source /etc/profile

Restart the computer

reboot

Unfinished

I hope you can give me more advice and join a group of 764640548 to learn and make progress together! ! ! ! ! ! ! ! ! !

CentOS system optimization script, unfinished