I had installed FC6 with squid proxy server.

Example:

acl blockfiles urlpath_regex "/etc/squid/blocks.files"
acl bad url_regex "/etc/squid/bad-files"
acl restricted url_regex "/etc/squid/restricted"
http_access deny single
http_access deny blockfiles
http_access deny restricted
http_access deny bad

# And finally deny all other access to this proxy
http_access allow localhost
http_access deny all


I had given the acl above http_access deny all line.

the above said acl are not blocking the sites given inside the files.

Please some one help me to solve the problem.

you could start by showing us the actual regexes, and the corresponding hits in your access.log.

/etc/squid/restricted file has following line in it

desktop.richmedia.in
www.las.ic.unicamp.br
www.mirrorservice.org
khoj.com
http://fedora.redhat.com/download/mirrors/fedora-core-5
fropper.com
orkut.com
download.microsoft.com
include.ebaystatic.com
~

and how to check the hits in /var/log/squid/access.log
if any error will be written in log file

We can use the follwing things

acl blockfiles url_regex -i '/etc/squid/blocks' etc