2008/6/7, Cameron Hutchison <<a href="mailto:lists@xdna.net">lists@xdna.net</a>>:<blockquote class="gmail_quote" style="margin:0;margin-left:0.8ex;border-left:1px #ccc solid;padding-left:1ex"> Bart Silverstrim <<a href="mailto:bsilver@chrononomicon.com">bsilver@chrononomicon.com</a>> writes: >So to be clear, the script I'm now using is... >********** >#!/bin/bash >join -v2 \ > <(iptables -L INPUT -n | grep DROP | awk '{print $4}' | sort -u) \ > <(grep -i slurp /var/log/apache-perl/access.log |awk '{print $1}' | >sort -u) | \ >egrep '^([[:digit:]]+[.]){3}[[:digit:]]+$' |\ >while read ip; do > iptables -A INPUT -s $ip -j DROP >done >*********** One more refinement I can see - grep piped into awk is redundant most of the time. The command pipeline: grep DROP | awk '{print $4}' can be replaced with awk '/DROP/ {print $4}' The second one: grep -i slurp .../access.log | awk '{print $1}' is a little trickier since awk does not have a non-verbose case-insensitive switch, so you have to do one of these: awk '/[Ss][Ll][Uu][Rr][Pp]/ {print $1}' .../access.log awk '/slurp/ {print $1}' IGNORECASE=1 .../access.log </blockquote>This thread seems to be a follow up to another thread. Which one? I would like to know what this script does (I'm a beginner so I can't really figure it out myself). ThanksJ.R.