Question

I have the following code in a PHP page. Some times when I delete the cache2.html file, I expect the php to recreate it and the next person will get the cache2.html instead of executing the php code. I get the following warning some times on the page and no content. Is it because of multiple users accessing the php concurrently? If so, How do I fix it? Thank you.

Warning: include(dir1/cache2.html) [function.include]: failed to
open stream: No such file or directory in
/home/content/54/site/index.php on line 8

<?php 
if (substr_count($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) ob_start("ob_gzhandler"); else ob_start();

$cachefile = "dir1/cache2.html";
if (file_exists($cachefile)) {
        include($cachefile); // output the contents of the cache file
} else {

/* HTML (BUILT USING PHP/MYSQL) */

$cachefile = "dir1/cache2.html";
$fp = fopen($cachefile, 'w'); 
fwrite($fp, ob_get_contents()); 
fclose($fp);
ob_flush(); // Send the output to the browser
}  
?>

Answer 1

Calls to file_exists() are themselves cached, so it’s likely you’re getting a return value of true even after the file is deleted. See:

http://us.php.net/manual/en/function.clearstatcache.php

So, you could do:

clearstatcache();
if (file_exists($cache)) {
    include($cache);
} else {
    // generate page
}

Alternatively, you could do something like this:

if (file_exists($cache) && @include($cache)) {
    exit;
} else {
    // generate page
}

Or better, if you’re deleting the cache file from within a PHP process, then just call clearstatcache() after you delete the file.