Finding out where curl was redirected

I'm using curl to make php send an http request to some website somewhere and have set CURLOPT_FOLLOWLOCATION to 1 so that it follows redirects. How then, can I find开发者_如何学JAVA out where it was eventually redirected?

You can do something like:

curl_getinfo($ch, CURLINFO_EFFECTIVE_URL); // returns the last effective URL

$ch = curl_init( "http://websitethatredirects.com" );
$curlParams = array(
   CURLOPT_FOLLOWLOCATION => true,
);
curl_setopt_array( $ch, $curlParams );
$ret = curl_exec( $ch );
$info = curl_getinfo( $ch );
print $info['url'];

This will show you the URL that you were ultimately redirected to.

test this snippets of code. It works fine for me :

$urls = array(
    'http://www.apple.com/imac',
    'http://www.google.com/'
);

$ch = curl_init();

curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

foreach($urls as $url) {
    curl_setopt($ch, CURLOPT_URL, $url);
    $out = curl_exec($ch);

    // line endings is the wonkiest piece of this whole thing
    $out = str_replace("\r", "", $out);

    // only look at the headers
    $headers_end = strpos($out, "\n\n");
    if( $headers_end !== false ) { 
        $out = substr($out, 0, $headers_end);
    }   

    $headers = explode("\n", $out);
    foreach($headers as $header) {
        if( substr($header, 0, 10) == "Location: " ) { 
            $target = substr($header, 10);

            echo "[$url] redirects to [$target]<br>";
            continue 2;
        }   
    }   

    echo "[$url] does not redirect<br>";
}

If you do not need the final body you can do it this way:

Set CURLOPT_HEADER and CURLOPT_NOBODY. The header "Location" should be returned and will contain the new url. Then perform the request with the new url if necessary.