#!/usr/local/bin/perl -w
use strict;

use LWP::UserAgent;
use HTTP::Request::Common;

my ($amount,$cf,$ct) = @ARGV[0..2];

my $request = GET "http://www.oanda.com/converter/classic?value="
                  . "$amount&exch=" . uc($cf) . "&expr=" . uc($ct);
$request->proxy_authorization_basic('username','password');

(my $ua = (new LWP::UserAgent))->proxy('http','http://yourproxyhere.com:1080');
my $resp = $ua->request($request);

die $resp->status_line if ($resp->is_error());
$_ = $resp->{_content};
s/^.*<!-- conversion result starts//s;
s/<!-- conversion result ends.*$//s;
s/<[^>]+>//g; s/[ \n]+/ /gs;
print $_, "\n"