Move WordPress Generated Files to ./thumbnails/ folder

instructions.md

Move WordPress Generated Files to ./thumbnails/ folder

Keeping WordPress Media Library updated even after a server move.

Instructions

1. Place the move.php script inside of a folder containing images containing both the Original and WordPress auto-generated thumbnails.
2. Run the script by navigating to it in the browser. All WordPress generated images will be moved to the ./thumbnails/ subfolder, all remaining images in your original folder are original images.
3. Upload all Original images to your server.
4. Install Add From Server Plugin to WordPress.
5. Select all original images within the Add From Server interface and import.
6. Upload all Thumbnail images to server as well.

move.php

<?php

$files = find_all_files(".");
$thumbnails = [];

foreach($files as $key => $file)
{
    $pathinfo = pathinfo($file);

    if (preg_match("/(\S*)-(\d*)x(\d*).(\S*)/", $file))
    {
        $thumbnails[] = $file;
        rename($file, './thumbnails/'.$file);
    }
    else if ($pathinfo['extension'] != 'php')
    {
        $originals[] = $file;
    }
}

echo '<h1>Thumbnails</h1>';
echo '<pre>';
var_dump($thumbnails);
echo '</pre>';

echo '<h1>Originals</h1>';
echo '<pre>';
var_dump($originals);
echo '</pre>';

function find_all_files($dir)
{
    $root = scandir($dir);
    foreach($root as $value)
    {
        if($value === '.' || $value === '..') {continue;}
        if(is_file("$dir/$value")) {$result[]="$dir/$value";continue;}
        foreach(find_all_files("$dir/$value") as $value)
        {
            $result[]=$value;
        }
    }
    return $result;
}