Create a local copy with absolute Path from a Contao VirtualFileSystem file.

CreateLocalCopyWithVfsController.php

namespace App\Controller;

use Contao\CoreBundle\Filesystem\VirtualFilesystemInterface;
use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
use Symfony\Component\Filesystem\Filesystem;

class CreateLocalCopyWithVfsController
{
    private readonly VirtualFilesystemInterface $filesStorage;
    private readonly ParameterBagInterface $parameterBag;

    public function __invoke(): void
    {
        $filePath = 'files/example.xlsx';
        if (!$this->filesStorage->fileExists($filePath)) {
            return;
        }

        $tmpFilePath = $this->parameterBag->get('kernel.project_dir').'/var/tmp/'.uniqid().'.xlsx';

        $fs = new Filesystem();
        $fs->dumpFile(
            $tmpFilePath,
            $this->filesStorage->readStream($filePath)
        );
        
        // Do something with the local file
        
        # ...
        
        // End Do something with the local file
        
        $fs->remove($tmpFilePath);
    }
}