Method 1 of traversing the tree

递归的深度优先的算法

define('DS', DIRECTORY_SEPARATOR);
function rec_list_files($from = '.')
{
    if(!is_dir($from)) {
        return array();
    }
    $files = array();
    if($dh = opendir($from))
    {
        while(false !== ($file = readdir($dh))) {

            if($file == '.' || $file == '..') {
                continue;
            }
            $path = $from . DS . $file;

            if (is_file($path)) {
                $files[] = $path;
            }
            $files = array_merge($files, rec_list_files($path));
        }
        closedir($dh);
    }
    return $files;
}
function profile($func, $trydir)
{
    $mem1 = memory_get_usage();
    echo '----------------------- Test run for '.$func.'() ';</li>
<li>    flush();</li>
<li>    $time_start = microtime(true);</li>
<li>    $list = $func($trydir);</li>
<li>    //print_r($list);</li>
<li>    $time = microtime(true) - $time_start;</li>
<li>    echo 'Finished : '.count($list).' files';
    $mem2 = memory_get_peak_usage();
    printf('Max memory for '.$func.'() : %0.2f kbytes Running time for '.$func.'() : %0.f s',
    ($mem2-$mem1)/1024.0, $time);
    return $list;
}
profile('rec_list_files', "D:wwwserver");
?>