[root@localhost ~]# vim dhcp-auto.sh

#######################################################
# File Name: dhcp_auto.sh
# Author: 寻音
# E-mail: lnhxzwb@126.com
# Created Time: Tue Mar 13 14:06:33 CST 2018
#========================================================== 
#!/bin/bash

cat << EOF
==========================<注意事项>==========================
1、本环境为Centos7以上版本，如果其它环境不能正常运行，请自行修改！
2、DHCP服务器子网地址必须与本机IP地址至少有一个为同一子网，否则将启动
失败！
EOF
read -p "本程序将安装并配置DHCP服务，是否继续(Y/N)：" dh
if [ $dh == "y" ] || [ $dh == Y ];then
yum repolist &>/dev/null
if [ $? = 0 ];then
echo "YUM源可用，正在安装DHCP，请稍等..."
yum -y install dhcp &>/dev/null
if [ $? = 0 ];then
echo "程序已安装成功，请根据提示配置"
read -p "请输入子网地址(例 10.10.10.0)：" net
read -p "请输入子网掩码(例 255.255.255.0)：" mask
read -p "请输入起始地址(例 10.10.10.10)：" sta
read -p "请输入结束地址(例 10.10.10.100)：" end
read -p "请输入DNS服务地址(例 1.2.4.8)：" dns
read -p "请输入域名地址(例 lncs.net)：" domain
read -p "请输入网关地址(例 10.10.10.1)：" gate
read -p "请输入默认租约时间(秒)：" dlease
read -p "请输入最大租约时间(秒)：" lease
echo "正在配置，请稍等..."
cd /etc/dhcp
>dhcpd.conf   
#清空配置文件
echo "subnet $net netmask $mask {" >>dhcpd.conf
echo "range $sta $end ;" >>dhcpd.conf
echo "option domain-name-servers $dns ;" >>dhcpd.conf
echo "option domain-name \"$domain\" ;" >>dhcpd.conf
echo "option routers $gate ;" >>dhcpd.conf
echo "default-lease-time $dlease;">>dhcpd.conf
echo "max-lease-time $lease;" >>dhcpd.conf
echo "}" >>dhcpd.conf
echo "配置已完成，正在启动DHCP服务..."
systemctl enable dhcpd
systemctl start dhcpd
if [ $? = 0 ];then
echo "恭喜你！DHCP已配置完成，请使用"
else
echo "配置失败，请检查或手动配置"
fi
else
echo "DHCP程序安装失败，请手动安装"
fi
else
echo "YUM源不可用，请更正后继续"
fi
elif [ ${dh} == "n" ] || [ ${dh} == N ];then
echo "程序将退出，再见！"
fi