CODEWITHSUNDEEP
phpweb-scrapingcurl
David
David

Reputation: 36414

PHP Curl following redirects

I'm trying to be a bit sneeky and as part of a learning process try and improve my page scraping skills.

One thing i've come across that I have yet to be able to solve is that certain sites will use an internal link which then redirects to an external link.

What I want to do is modify some curl code to follow the redirects until they stop and then obtain the final resting place URL.

Anyone recommend some code for me?

I have this at the moment, but it's not following the redirects properly at the moment.

        $opts = array(CURLOPT_URL => $url,
                      CURLOPT_RETURNTRANSFER => true,
                      CURLOPT_HEADER => true,
                      CURLOPT_FOLLOWLOCATION => true);      

        $curl = curl_init(); 
        curl_setopt_array($curl, $opts);  
        $str = curl_exec($curl);  
        curl_close($curl);

Upvotes: 10

Views: 30928

Answers (2)

Manish
Manish

Reputation: 5213

http.//php.net/manual/en/ref.curl.php 

   function get_final_url( $url, $timeout = 5 )
 {
    $url = str_replace( "&", "&", urldecode(trim($url)) );

   $cookie = tempnam ("/tmp", "CURLCOOKIE");
$ch = curl_init();
curl_setopt( $ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20041001 Firefox/0.10.1" );
curl_setopt( $ch, CURLOPT_URL, $url );
curl_setopt( $ch, CURLOPT_COOKIEJAR, $cookie );
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
curl_setopt( $ch, CURLOPT_ENCODING, "" );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch, CURLOPT_AUTOREFERER, true );
curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, $timeout );
curl_setopt( $ch, CURLOPT_TIMEOUT, $timeout );
curl_setopt( $ch, CURLOPT_MAXREDIRS, 10 );
$content = curl_exec( $ch );
$response = curl_getinfo( $ch );
curl_close ( $ch );

if ($response['http_code'] == 301 || $response['http_code'] == 302)
{
    ini_set("user_agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20041001 Firefox/0.10.1");
    $headers = get_headers($response['url']);

    $location = "";
    foreach( $headers as $value )
    {
        if ( substr( strtolower($value), 0, 9 ) == "location:" )
            return get_final_url( trim( substr( $value, 9, strlen($value) ) ) );
    }
}

if (    preg_match("/window\.location\.replace\('(.*)'\)/i", $content, $value) ||
        preg_match("/window\.location\=\"(.*)\"/i", $content, $value)
)
{
    return get_final_url ( $value[1] );
}
else
{
    return $response['url'];
   }
}

Upvotes: 25

Tchoupi
Tchoupi

Reputation: 14691

If you can't use CURLOPT_FOLLOWLOCATION, I suggest you use a recursive method like this one:

function getUrl($url, $count) {

    // max number of redirects
    if ($count > 5) {
        return false;
    }

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HEADER, true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    $data = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

    curl_close($ch);

    if (!$data) {
        return false;
    }

    $dataArray = explode("\r\n\r\n", $data, 2);

    if (count($dataArray) != 2) {
        return false;
    }

    list($header, $body) = $dataArray;
    if ($httpCode == 301 || $httpCode == 302) {
        $matches = array();
        preg_match('/Location:(.*?)\n/', $header, $matches);

        if (isset($matches[1])) {
            return getUrl(trim($matches[1]), $count + 1);
        }
    } else {
        return $body;
    }
}

Upvotes: 1

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