写了个 ban 迅雷的脚本，但是总出问题，大佬们帮忙看看哪里不太好？

没办法 n1 那个盒子上只有 transmission 和 qbitorrent 两个，发现 tr 有命令行工具，所以就用这个了。

#!/bin/sh
alias tr="/usr/bin/transmission-remote 127.0.0.1"
nums=`tr --list|grep -oE "^ +[0-9]+"|grep -oE "[0-9]+"`
# all torrents.
for i in $nums
do
	peers=`tr -t $i -ip|grep Xunlei|grep -oE '^([0-9]+\.)+[0-9]+'`
	# for each XunLei peer's ip
	for peerip in $peers
	do
		# if iptables has rule, do not append.
		ruletest=`iptables --list | grep $peerip `
		echo $ruletest
		if [ -z "$ruletest" ] 
		then
			# append rule.
			iptables --append OUTPUT --dest $peerip -j DROP
			echo "blockIP:$peerip"
		else
			echo "IPAddress:$peerip blocked."
		fi
	done
done