deleteEmptyFiles.php

<?php

/**
 * Recursively searches the current directory and deletes any file that has only an opening PHP tag and empty lines
 * Thanks to Jan for providing the solution here: 
 * https://stackoverflow.com/questions/44185401/delete-file-containing-opening-php-tag-and-empty-lines
 */

$directory = new RecursiveDirectoryIterator('./');
$iterator = new RecursiveIteratorIterator($directory);
$regex = '~\A\Q<?php\E\s+\Q\E\Z~';
$deletedCount = 0;

foreach($iterator as $name => $file) {
    $content = file_get_contents($file);
    if (preg_match($regex, $content)) {
        print "deleted " . $name . "\n";
        unlink($file);
        $deletedCount++;
    }
}

print "Deleted $deletedCount empty files.\n";