pay pal ipn example

error_reporting(E_ALL ^ E_NOTICE);
// Read the post from PayPal and add 'cmd'
$req = 'cmd=_notify-validate';
if(function_exists('get_magic_quotes_gpc'))
{
$get_magic_quotes_exits = true;
}
foreach ($_POST as $key => $value)
// Handle escape characters, which depends on setting of magic quotes
{
if($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1){
$value = urlencode(stripslashes($value));
} else {
$value = urlencode($value);
}
$req .= "&$key=$value";
}
// Post back to PayPal 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);


// Process validation from PayPal
// TODO: This sample does not test the HTTP response code. All
// HTTP response codes must be handles or you should use an HTTP
// library, such as cUrl

if (!$fp) { // HTTP ERROR
}
else {
// NO HTTP ERROR
fputs ($fp, $header . $req);
while (!feof($fp)) {
$res = fgets ($fp, 1024);
if (strcmp ($res, "VERIFIED") == 0) {
$myFile = "testFile.txt";
$fh = fopen($myFile, 'w') or die("can't open file");
$stringData = "ffff";
fwrite($fh, $stringData);
$stringData =$x;
fwrite($fh, $stringData);
fclose($fh);
} else if (strcmp ($res, "INVALID") == 0) {
$myFile = "testFile.txt";
$fh = fopen($myFile, 'w') or die("can't open file");
$stringData = "0000";
fwrite($fh, $stringData);
$stringData =$x;
fwrite($fh, $stringData);
fclose($fh);
}
}
}
fclose ($fp);