Recursive directory listing

Question

I'm trying to optimize performance for recursive directory listing with some exceptions:

function listdir($basedir) {
 global $root, $ignore_dirs, $ignore_files, $filetypes, $ignore_starts_with;
 if ($handle = @opendir($basedir)) { 
 while (false !== ($fn = readdir($handle))) { 
 if ($fn != '.' && $fn != '..') {
 $s = true;
 foreach ($ignore_starts_with as $pre) if (strpos($fn, $pre) === 0) $s = false;
 $dir = $basedir."/".$fn;
 if ($s && is_dir($dir) && !in_array($fn, $ignore_dirs)) {
 listdir($dir);
 } else {
 if ($s && !in_array($fn,$ignore_files) && preg_match("/[^.\/].+\.($filetypes)$/",$dir,$fname)) printlink($fname[0]);
 } 
 } 
 } 
 closedir($handle); 
 } 
}

• Ed Swangren: Optimize how? Where is the bottleneck? What have your profiling results shown?
• 350D: im not shire about foreach construction, and many if's
• Ed Swangren: Well, I would prove that is actually a bottleneck before potentially wasting time optimizing them out (if that's even possible). For example, if 98% of your time is spent doing I/O then removing an if statement or a loop is pointless. That said, your $s variable will only hold the last assignment, so you may as well just break out of it the first time that condition is met.

Answer 1

First of all, I'd use RecursiveDirectoryIterator, removed globals and corrected formatting.

Then used Xdebug + CacheGrind to try different versions.