closing all and opening specific ports
 

can anyone give me the commands to close all the ports and open specific ports on the computer? using iptables

What time is it?

Time to read the IPTABLES HOWTO. :study:

Do you have an iptables scripts? if yes, just put your rules for port you want to open first
(example: $IPTABLES -A INPUT -s 0/0 --dport http -j ACCEPT)
then at the end of your script add a command like :
( $IPTABLES -A INPUT -s/s -j DROP )


iptables uses the first applicable rules it can find, so if there is no rules about "another port" than this one will be use as default.