This custom error page shows some standard error information and reports the error to the webmaster by e-mail.

/* create a .htaccess file in your root and enter these most common error code definitions

ErrorDocument 400 /error.php?err=400
ErrorDocument 401 /error.php?err=401
ErrorDocument 403 /error.php?err=403
ErrorDocument 404 /error.php?err=404
ErrorDocument 500 /error.php?err=500

*/

// save this code below in file name "error.php"
if (isset($_GET['err'])) {
$errorNum = $_GET['err'];
} else {
$errorNum = "undef. number";
}

$emailaddress = "your@mail.com";
/*
you have to create this file and enter there all URL's with bad links and
all IP addresses which are hot linking not existing files, example:
146.34.34.110
http://www.somedomain.com/filename.htm
*/
$filename = "http://".$_SERVER['HTTP_HOST']."/blocked_ref.txt";

// if the http referer is not empty check the file for exsiting URL's
if (!empty($_SERVER['HTTP_REFERER'])) {
$bad_ref = file ($filename);
$bad_counter = 0;
foreach ($bad_ref as $val) {
if (substr($_SERVER['HTTP_REFERER'], 0, 20) == substr($val, 0, 20)) {
$bad_counter++;
}
}
if ($bad_counter > 0) {
header("Location: http://".$_SERVER['HTTP_HOST']);
die();
} else {
$errortime = (date("d M Y h:m:s"));
$message = $errorNum." Error Report\r\n\r\nA ".$errorNum." error was encountered by ".$_SERVER['REMOTE_ADDR'];
$message .= " on $errortime.\r\n\r\n";
$message .= "The URI which generated the error is: \nhttp://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']."\r\n\r\n";
$message .= "The referring page was:\n".$_SERVER['HTTP_REFERER']."\r\n\r\n";
$message .= "The used client was:\n".$_SERVER['HTTP_USER_AGENT']."\r\n\r\n";
$headers = "From: ".$emailaddress."\nDate: ".$errortime." +0100\n";
$subject = "Error: ".$errorNum." from ".$_SERVER['HTTP_REFERER'];
mail($emailaddress, $subject, $message, $headers);
}
} else { // at last check if there are already some bad IP Addresses
$bad_ref = file ($filename);
$very_bad_counter = 0;
foreach ($bad_ref as $val) {
if (substr($_SERVER['REMOTE_ADDR'], 0, 10) == substr($val, 0, 10)) {
$very_bad_counter++;
}
}
if ($very_bad_counter > 0) {
header("Location: http://www.google.com"); // or some other nice URL
die();
}
}
// place here the html code you want to show the visitor, like
echo "

Some error...

";
?>