Paypal sandbox notify_url file not working - php

Question

Can someone please tell me whats wrong with this code.
I am trying for payment integration with Paypal with html form. I have specified the notify_url, payment goes all right but i am not able to enter in this block if (strcmp($res, "VERIFIED") == 0){}
// Response from Paypl
// read the post from PayPal system and add 'cmd'
$req = 'cmd=_notify-validate';
foreach ($_POST as $key => $value) {
$value = urlencode(stripslashes($value));
$value = preg_replace('/(.*[^%^0^D])(%0A)(.*)/i', '${1}%0D%0A${3}', $value); // IPN fix
$req .= "&$key=$value";
}
// assign posted variables to local variables
$data['item_name'] = $_POST['item_name'];
// post back to PayPal system to validate
$header = "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n";
$fp = fsockopen('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30);
if (!$fp) {
// HTTP ERROR
echo 'HTTP ERROR';
} else {
file_put_contents('test1.txt', 'test');
fputs($fp, $header . $req);
while (!feof($fp)) {
$res = fgets($fp, 1024);
if (strcmp($res, "VERIFIED") == 0) {
echo 'SUCCESS';
} else if (strcmp($res, "INVALID") == 0) {
echo 'INVALID';
}
}
fclose($fp);
}

Answer 1

Use CuRl method to POST data back instead of fsock here is link:https://developer.paypal.com/webapps/developer/docs/classic/ipn/ht_ipn/ or My suggestion is Use AngellaEye library which is more effective and useful for Paypal integration here is link:http://www.angelleye.com/how-to-integrate-paypal-with-php-class-library/
Download it from this link and go throgh it.