General :: Cannot Redirect URL To Another URL When The Link Is Down With Squid

i have installed squid 2.6 on my centos. i have writen a shell script to ping a network and write to a file. write '1' if network up and '0' if network down. After that,a perl script will read the file and do the redirection.Perl will redirect to a fix URL [URL] if the network down and do nothing when it up. i have put my perl script in squid.conf at url_rewrite_program /my_file_path.

below is my shell script for pinging:

Quote:

#!/bin/bash
while [ 1 ]
do
HOST=143.148.137.134

[code]....

My problem is client browser are not redirect to www.google.com even the network is down. It should go to the fix URL when the user click any URL in network down situation.it just appear cannot resolve host.