#read the post from partner system and add 'cmd'
read (STDIN, $query, $ENV{'CONTENT_LENGTH'});
$query .= '&cmd=_notify-validate'; 

# post back to partner system to validate
use LWP::UserAgent; 
$ua = LWP::UserAgent->new; 

my $req = HTTP::Request->new(POST => 'http://www.foo.bar/test.pl');

$req->content_type('application/x-www-form-urlencoded'); 
$req->content($query); 
my $res = $ua->request($req); 

# split posted variables into pairs 
@pairs = split(/&/, $query); 
$count = 0; 
foreach $pair (@pairs) { 
    ($name, $value) = split(/=/, $pair); 
    $value =~ tr/+/ /; 
    $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg; 
    $variable{$name} = $value; 
    print STDERR "$name => $value\n";
    $count++; 
}