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package HTTP::ProxyAutoConfig;

=head1 NAME

HTTP::ProxyAutoConfig - provides a unifed way to get the proxy information

=head1 SYNOPSIS

HTTP::ProxyAutoConfig is a module that allows perl scripts that need
access to proxy servers to utilize the standard proxy settings provided
by an IT department.

=head1 DESCRIPTION

This module provides a consistent method for finding the proxy server
needed to talk to for a given URL.  It can handle parsing the http_proxy,
https_proxy, ftp_proxy, and http_auto_proxy variables to determine
what it is you want it to do.  If you set the http_auto_proxy variable
it overrides the others and fetches the PAC file from there and uses
those settings.

Access to the proxy information is provided in a single function call
to FindProxyForURL(url,host).  A string is returned that tells you what
to do, either "DIRECT", "PROXY host:port", or "SOCKS host:port".

The Proxy Auto Config format and rules are defined at Netscape:

http://home.netscape.com/eng/mozilla/2.0/relnotes/demo/proxy-live.html

The file basically works by defining a JavaScript function called
FindProxyForURL.  This module fetches that file and converts the
JavaScript function into a Perl function and then defines the Perl
function with that converted data.

=head1 METHODS

  new(url) - creates the FindProxyForURL function and the object.
             The url argument is optional, and points to the auto-proxy
             file provided on your network.  If you do not specify a
             url, then it will check the http_auto_proxy variable,
             followed by the http_proxy, https_proxy, and ftp_proxy
             variables.

  my $pac = new HTTP::ProxyAutoConfig("http://foo.bar/auto-proxy.pac");
  my $pac = new HTTP::ProxyAutoConfig();

  FindProxyForURL(url,host) - takes the url, and the host (minus
                              port) from the URL, and determines the
                              action you should take to contact that
                              host.  It returns one of three things:

                                DIRECT           - connect directly to them
                                PROXY host:port  - connect via the proxy
                                SOCKS host:port  - connect via SOCKS

  FindProxy(url) - calls the FindProxyForURL function and passes it the
                   correct options.  This is just a wrapper.

  Reload() - allows you to fetch the PAC again and regenerate the
             FindProxyForURL function based on anything you might
             have changed in the environment.

=head1 AUTHOR

By Ryan Eatmon in May of 2001

=head1 COPYRIGHT

This module is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=cut

use strict;
use Carp;
use Sys::Hostname;
use IO::Socket;
use POSIX;