$username="admin";
$password="admin";
$url="http://www.yourdomain.com/";
$cookie="cookie.txt";

$postdata = "log=". $username ."&pwd=". $password ."&wp-submit=Log%20In&redirect_to=". $url ."wp-admin/&testcookie=1";
$ch = curl_init();
curl_setopt ($ch, CURLOPT_URL, $url . "wp-login.php");
curl_setopt ($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt ($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6");
curl_setopt ($ch, CURLOPT_TIMEOUT, 60);
curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($ch, CURLOPT_COOKIEJAR, $cookie);
curl_setopt ($ch, CURLOPT_REFERER, $url . "wp-admin/");
curl_setopt ($ch, CURLOPT_POSTFIELDS, $postdata);
curl_setopt ($ch, CURLOPT_POST, 1);
$result = curl_exec ($ch);
curl_close($ch);
echo $result;
exit;

curl_setopt($ch,CURL_COOKIEFILE, '');  // Enables session support

curl_close($ch);
header('location: blog/wordpress/wp-admin/');
die();