How to display Apache's default 404 page in PHP

Question

I have a webapp that needs to process the URI to find if a page exists in a database. I have no problem directing the URI to the app with .htaccess:

Options +FollowSymlinks
RewriteEngine on
RewriteCond %{SCRIPT_FILENAME} !-f
RewriteRule ^(.*)$ index.php?p=$1 [NC]

My problem is that if the page does not exist, I do not want to use a custom 404 handler written in PHP, I would like do show the default Apache 404 page. Is there any way to get PHP to hand execution back to Apache when it has determined that the page does not exist?

Answer 1

I don't think you can "hand it back" to Apache, but you can send the appropriate HTTP header and then explicitly include your 404 file like this:

if (! $exists) {
    header("HTTP/1.0 404 Not Found");
    include_once("404.php");
    exit;
}

Update

PHP 5.4 introduced the http_response_code function which makes this a little easier to remember.

if (! $exists) {
    http_response_code(404);
    include_once("404.php");
    exit;
}