DHCP service efficiency script

Green script

#!/bin/bash
CONFIG=/etc/dhcp/dhcpd.conf
CONFIG_option="
subnet 192.168.${
    
    1}.0 netmask 255.255.255.0 {
    
    
range 192.168.${
    
    1}.${
    
    2} 192.168.${
    
    1}.${
    
    3};
option routers 192.168.${
    
    1}.1;
option broadcast-address 192.168.${
    
    1}.255;
default-lease-time 600;
max-lease-time 7200;
}"

if [ ! -e $CONFIG ];then
        yum -y install dhcp &>/dev/null
        echo -e "\033[32m The dhcpd install complete!  \033[0m"
fi

if [ $# -eq 3 ];then
        echo "$CONFIG_option" > $CONFIG
        if [ $? -eq 0 ];then
                echo -e "\033[32m config is successfully!\033[0m"
                systemctl start dhcpd &>/dev/null
                if [ $? -eq 0 ];then
                        echo -e "\033[32m The dhcpd is running!\033[0m"                
                else
                        echo -e "\033[31m The dhcpd is running failed!\033[0m" 
                fi
 		else
                echo -e "\033[31m config is failed!\033[0m"
                exit
        fi
else
        echo -e "\033[31m Error,please input location variable! \033[0m"        
		echo -e "\033[31m syntax:sh $0 13 100 200\033[0m"
        echo -e "\033[31m subnet:[1-255]\nrange start:[2-254]\nrange end:[2-254]\nrange start < range end\033[0m"
fi

Execute it

[root@haha ~]# sh DHCP.sh 13 100 150
 config is successfully!
 The dhcpd is running!

[root@haha ~]# sh DHCP.sh 
 Error,please input location variable! 
 syntax:sh DHCP.sh 13 100 200
 subnet:[1-255]
range start:[2-254]
range end:[2-254]
range start < range end