[SOLVED] PHP readdir() not returning files in order

PHP readdir() not returning files in order

I have the below code that I run to list files within a directory. I would like to sort the output by some way. Preferably filename or by date of upload. Is this even possible?

<?php
  if ($handle = opendir('./xyz')) {
    while (false !== ($file = readdir($handle))) {
        if ($file != "." && $file != "..") {
          $thelist .= '<a href="./abc/xyz/'.$file.'">'.$file.'</a><br>';
        }
    }
  closedir($handle);
  }
?>
<h1>List of files:</h1>
<ul><?php echo $thelist; ?></ul>

EDIT: New code with update.

<?php
array_multisort(array_map('filectime', $files = glob('./xyz/*.*')), SORT_DEC, $files);
?>

<h1>List of files:</h1>
<ul><?php foreach($files as $file) {
    echo '<a href="./abc/'.$file.'">'.$file.'</a><br>';
}
?></ul>

Solution

You can't sort with readdir which reads them in the order that they are stored in the file system. You can read them into an array and sort that. array_multisort works well and you can replace filectime with other functions:

array_multisort(array_map('filectime', $files = glob('./xyz/*.*')),
                SORT_ASC, $files);

This gets all files into an array $files, maps to filectime to get the time, sorts on that and then sorts the $files array on that.
For alphabetical just use sort or rsort after glob.

Once you have the sorted array just loop it and display or build your string as you were:

foreach($files as $file) {
    echo '<a href="./abc/xyz/'.$file.'">'.basename($file).'</a><br>';
}