Question: I'm making a real simple "backend" (PHP5) for two flash/air-applications. One of them will upload a photo, the backend will save it to a folder, and the second app will poll the backend for new photo's and show them. 

I don't got any access to a database, so the backend has to be pure PHP5 and nothing more. That's why I chose to save the images to a folder (with a timestamp in their names) and use readdir() to get them back. 

This all works like a charm. Nevertheless, I would really like to make sure the backend only returns photo's that are completely uploaded, preventing the second app to try to load an unfinished image. Are there any methods/tricks that I can use to validate a file?

Answer: 
I think you want to ignore any file that *begins* with a dot (.) and not just the filename.

```
<?php
if ($handle = opendir('assets/automotive')) {
    $ignore = array( 'cgi-bin', '.', '..','._' );
    while (false !== ($file = readdir($handle))) {
        if (!in_array($file,$ignore) and substr($file, 0, 1) != '.') {
            echo "$file\n";
        }
    }
    closedir($handle);
}
?>

```
`in_array()` [takes two parameters](http://php.net/manual/en/function.in-array.php): the thing you want to find, and the array to search in.
You want:

```
if ( !in_array($file, $ignore))

```