#!/bin/bash

search=$(grep --color=never -P '^[ \t]*search +[a-zA-Z_-]+' < /etc/resolv.conf | sed -e 's/^[ \t]*search //');
proxy='';

for domain in ${search}; do
  nslookup wpad.${domain} 1> /dev/null 2> /dev/null &&  proxy=$(wget --no-proxy -O- http://wpad.${domain}/wpad.dat 2> /dev/null | grep -P "PROXY [0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}:[0-9]{1,6}" | head -n1 | sed -e 's/[^0-9.:]//g');
  if [ -n ${proxy} ]; then
    export http_proxy="http://$proxy";
    return; 
  fi
done