Back in 2001 I wrote a Perl/Tk script to download tracks from a GPS unit and overlay them onto maps and aerial photos from Microsoft's TerraServer. I used Win32::Internet (I needed the headers to tell GIFs from JPEGs.) to connect to and make requests from terraserver.microsoft.com via the following subroutines:
sub StartInternet {
    $Internet = Win32::Internet->new
}

sub Get {
    my ($url, $req) = @_;
    my $http;
    my $result = $Internet->HTTP($http, $url, 'anonymous', '');
    if ($result) {
        my ($status, $header, $content) = $http->Request("/$req");
        $http->Close;
        return ($header, $content)
    } else {
        return undef
    }
}

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Typical values for $url and $req would be:
$url = 'terraserver.microsoft.com';
$req = 'tile/tile.asp?T=1&S=13&X=321&Y=3329&Z=10'

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and the script worked just fine.

Now, however, Microsoft has changed the url to terraserver-usa.com and seems to be herding everyone into using their .NET RPCs. Nonetheless, the website is still able to retrieve individual tiles using addresses like:

terraserver-usa.com/tile.ashx?T=1&S=13&X=321&Y=3329&Z=10

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Yet, when reconfigured for the new addresses, my script no longer works. I get a "400 Bad request" each time. So my question is, what is my browser (Opera 6 on Windows) sending to the server that Win32::Internet isn't, or vice-versa, and how can I turn a bad request into a good one? (I'd prefer not to use SOAP. It seems like overkill just for accessing static content.)

In reply to Win32::Internet and TerraServer by Dr. Mu

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