iPhoto Library Manager (Revisited)

For anyone interested, attached below (in the Extended Entry) is the script I run nightly from cron that informs me by email when my current iPhoto Library is getting big enough to consider taking an action with iPhoto Library Manager to create a new one.

A couple of notes:

1. Yes, the script uses the CLI version of PHP. I'm much more familiar with the PHP language than I am with tools like Perl.
2. The script uses the knowledge that I name my iPhoto Libraries according to the form "iPhoto-Library-20030521", so that the last entry in a directory listing is the currently used Library (and the one whose size should be calculated).
3. I've removed the <? ?> PHP delimiters from the script example, to prevent execution when you view it (since my blog is parsed by PHP).

    #! /usr/local/bin/php
    [BEGIN PHP]

    $LibraryLocation  = '/Users/mhenders/Pictures';
	$LibraryPrefix = 'iPhoto-';
    $MaxDesiredSize   = 600; // in megabytes
	$to = 'matt@makalumedia.com';
    $subject = 'iPhoto Library Size Warning [makalup1]';

    function getSubDirs($dir_name)
    {
    $subdirectories = array();
    $files = array();

        if(is_dir($dir_name) and is_readable($dir_name)) {
        	$d = dir($dir_name);
        	while (false !== ($f = $d->read())) {
        		// skip . and ..
        		if (('.' == $f) || ('..' == $f)) {
        			continue;
        		}
        		if (is_dir("$dir_name/$f")) {
        			array_push($subdirectories,"$dir_name/$f");
        		} else {
        			array_push($files,"$dir_name/$f");
        		}
        	}
        	$d->close();
        }
        return $subdirectories;

    }

    $subdirectories = getSubDirs($LibraryLocation);

    foreach( $subdirectories as $subdir ) {
			if(ereg($LibraryLocation."/".$LibraryPrefix,$subdir))
    {
    $output = exec("du -sk ".$subdir);
    ereg('([0-9]+)',$output,$size);
    $size = $size[0];
    $foundLibrary = $subdir;
    }
    }

    $checkSize = round($size/1000,0); // convert KB to MB

    if($checkSize > $MaxDesiredSize)
    {
    $message = "iPhoto Library Size Warningn";
    $message .= "===========================nn";
    $message .= "Library: $foundLibraryn";
    $message .= " Size: $checkSize MBnn";
    $message .= "(You specified to be notified when the ";
    $message .= "library size is greater than $MaxDesiredSize MB.)";

        $subject .= " [$checkSize MB]";

        mail($to,$subject,$message);

    }

    [END PHP]