在PHP中使用CURL时，由主机标头覆盖的URL

Question

I have the following script:

$url = "http://yahoo.com/";
$referer = 'whocares.com';

$header = array();
$header[0]  = "Accept: text/xml,application/xml,application/xhtml+xml,";
$header[0] .= "text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5";

$header[] = "Cache-Control: max-age=0";
$header[] = "Connection: keep-alive";
$header[] = "Keep-Alive: 300";
$header[] = "Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7";
$header[] = "Accept-Language: en-us,en;q=0.5";
$header[] = "Pragma: "; // browsers = blank
$header[] = "X_FORWARDED_FOR: " . $ip;
$header[] = "REMOTE_ADDR: " . $ip;
$header[] = "Host: example.com";


 $options = [
        CURLOPT_RETURNTRANSFER => true,     // return web page
        CURLOPT_HEADER         => false,     // return headers
        CURLOPT_FOLLOWLOCATION => false,     // follow redirects
        CURLOPT_ENCODING       => "",       // handle all encodings
        CURLOPT_AUTOREFERER    => false,     // set referer on redirect
        CURLOPT_CONNECTTIMEOUT => 120,      // timeout on connect
        CURLOPT_TIMEOUT        => 120,      // timeout on response
        CURLOPT_MAXREDIRS      => 0,       // stop after 10 redirectsi
        CURLOPT_HTTPHEADER =>  $header
    ];

   $curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_USERAGENT, 'Googlebot/2.1 (+http://www.google.com/bot.html)');
curl_setopt($curl, CURLOPT_HTTPHEADER, $header);

curl_setopt($curl, CURLOPT_REFERER, 'http://www.google.com');
curl_setopt($curl, CURLOPT_ENCODING, 'gzip,deflate');
curl_setopt($curl, CURLOPT_AUTOREFERER, true);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_TIMEOUT, 120);
curl_setopt($curl, CURLOPT_VERBOSE, 1);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 120);
 curl_setopt($curl, CURLOPT_MAXREDIRS, 12);
curl_setopt($curl, CURLOPT_URL, $url);


$remoteSite = curl_exec($curl);
$header = curl_getinfo($curl);
curl_close($curl);

echo $remoteSite;

Running this I would expect to navigate to http://yahoo.com and send the yahoo server a header that includes Host: example.com but that doesn't happen, instead, Example.com is requested. How can I use curl to open Yahoo.com and send Host: example.com to yahoo in the headers?

I don't care about using CURL. I need a php script that works as a proxy and when I open my script in the browser it has to open a certain URL send the Host: example.com header to that URL (among others) and reply me back (with the headers that the remote server sent to the script in the answer).