Extra HTTP header from proxy

http_proxy_extra_header_demo.php

<?php

/*
 * Description: Demonstration of the "extra HTTP header" issue using a
 *              web proxy. The problem becomes significant when the
 *              header is output with the body alltogether.
 * 
 * Solution:    See https://stackoverflow.com/a/17059693/3375584
 */

$url = 'https://www.zdv.uni-mainz.de/feed/';
$use_proxy  = true;   // Turn proxy on or off
$use_fix    = false;  // Turn fix on or off

$ch = curl_init();
curl_setopt_array($ch, [
    CURLOPT_URL => $url,
    CURLOPT_HEADER => true,
    CURLOPT_RETURNTRANSFER => true
]);
if ($use_proxy) {
    curl_setopt_array($ch, [
        CURLOPT_PROXY => 'http://webproxy.zdv.uni-mainz.de/',
        CURLOPT_PROXYPORT => 3128
    ]);
}
$response = curl_exec($ch);
curl_close($ch);

// cURL automatically handles Proxy rewrites, remove the "HTTP/1.0 200 Connection established" string
$extra_headers = [
    "HTTP/1.0 200 Connection established\r\n\r\n",
    "HTTP/1.1 200 Connection established\r\n\r\n"
];
if ($use_fix) {
    foreach($extra_headers as $extra_header) {
        print 1;
        if (false !== stripos($response, $extra_header)) {
            $response = str_ireplace($extra_header, '', $response);
            break;
        }
    }
}

list($header, $body) = explode("\r\n\r\n", $response, 2);
print $header;

/* End of Demo */