脚本是借鉴老男孩培训机构的， 感谢感谢~   

 mkdir -p /server/scripts cat >> /server/scripts/env.sh <<END #!/bin/bash #author Xiongchao #qq 704816384 #mail 704816384@qq.com #selinux off 
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config  
setenforce 0 
#iptables off 
/etc/init.d/iptables stop 
chkconfig iptables off #services  
chkconfig|egrep -v "crond|sshd|network|rsyslog|sysstat"|awk '{print "chkconfig",$1,"off"}'|bash #add users 
useradd oldboy 
echo "123456" |passwd --stdin oldboy 
\cp /etc/sudoers /etc/sudoers.ori 
echo "oldboy  ALL=(ALL) NOPASSWD: ALL " >>/etc/sudoers 
tail -1 /etc/sudoers 
visudo -c 
#ntpdate ntpdate times.aliyun.com 
echo '#time sync ' >>/var/spool/cron/root 
echo '*/5 * * * * /usr/sbin/ntpdate times.aliyun.com >/dev/null 2>&1' >>/var/spool/cron/root 
crontab -l 
#ulimit 
echo '* - nofile 65535 ' >>/etc/security/limits.conf  
tail -1 /etc/security/limits.conf
#kernel cat >>/etc/sysctl.conf<<EOF 
net.ipv4.tcp_fin_timeout = 2 
net.ipv4.tcp_tw_reuse = 1 
net.ipv4.tcp_tw_recycle = 1 
net.ipv4.tcp_syncookies = 1 
net.ipv4.tcp_keepalive_time = 600 
net.ipv4.ip_local_port_range = 4000    
65000 net.ipv4.tcp_max_syn_backlog = 16384 
net.ipv4.tcp_max_tw_buckets = 36000 
net.ipv4.route.gc_timeout = 100 
net.ipv4.tcp_syn_retries = 1 
net.ipv4.tcp_synack_retries = 1 
net.core.somaxconn = 16384 
net.core.netdev_max_backlog = 16384 
net.ipv4.tcp_max_orphans = 16384 
#iptables 
net.nf_conntrack_max = 25000000 
net.netfilter.nf_conntrack_max = 25000000 
net.netfilter.nf_conntrack_tcp_timeout_established = 180 
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120 
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60 
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120 
EOF
#yumrepo 
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo 
mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup  
mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup  
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo 
END