rewinddir

/* Source Code */
<?php
$dir = "/images/";
// Open a directory, and read its contents
if (is_dir($dir)){
 if ($dh = opendir($dir)){
 // List files in images directory
 while (($file = readdir($dh)) !== false){
 echo "filename:" . $file . "<br>";
 }
 rewinddir();
 // List once again files in images directory
 while (($file = readdir($dh)) !== false){
 echo "filename:" . $file . "<br>";
 }
 closedir($dh);
 }
}
?>

/* Result */
filename: cat.gif
filename: dog.gif
filename: horse.gif
filename: cat.gif
filename: dog.gif
filename: horse.gif

It is crucial to note that rewinddir() does not simply start over at the beginning of the SAME directory list. Instead, this function first re-reads the directory - thus any file that were deleted (or inserted) since the original opendir() will be reflected after "rewinding".
In that respect, rewinddir() is equivalent to a closedir(), opendir() sequence, but without obtaining a new handle.