bash嵌套循环不起作用

Question

I've written a bash script to ban country IP blocks from my router.

Why is it that the following works:

for ip in $(wget -qO- http://ipdeny.com/ipblocks/data/countries/cn.zone)
do 
    iptables -I wanin -s "$ip" -j DROP
done

But the following in which I nest multiple countries does not?

for country in CN AD
do 
    for ip in $(wget -qO- http://ipdeny.com/ipblocks/data/countries/$country.zone) 
    do 
        iptables -I wanin -s "$ip" -j DROP
    done
done

Answer 1

See that it's case sensistive. You have

for country in CN AD;

See that you are using caps here. If you use

for country in cn ad;

Then it should work. Try out yourself the link not working upper case zone and working with lower case zone

Answer 2

Since country is expected to be lowercase you may add declare -l country like this:

declare -l country
for country in CN AD; do 
  for ip in $(wget -qO- http://ipdeny.com/ipblocks/data/countries/$country.zone); do
    iptables -I wanin -s "$ip" -j DROP
  done
done

or use the ${var,,} parameter expansion :

for country in CN AD; do 
  for ip in $(wget -qO- http://ipdeny.com/ipblocks/data/countries/${country,,}.zone); do
    iptables -I wanin -s "$ip" -j DROP
  done
done