php ライブラリ「league/flysystem」を使ってファイルの読み込みや書き込みを行う

composer require league/flysystem

<出力結果>
Using version ^1.0 for league/flysystem
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 1 install, 0 updates, 0 removals
  - Installing league/flysystem (1.0.69): Downloading (100%)
league/flysystem suggests installing league/flysystem-eventable-filesystem (Allows you to use EventableFilesystem)
league/flysystem suggests installing league/flysystem-rackspace (Allows you to use Rackspace Cloud Files)
league/flysystem suggests installing league/flysystem-azure (Allows you to use Windows Azure Blob storage)
league/flysystem suggests installing league/flysystem-webdav (Allows you to use WebDAV storage)
league/flysystem suggests installing league/flysystem-aws-s3-v2 (Allows you to use S3 storage with AWS SDK v2)
league/flysystem suggests installing league/flysystem-aws-s3-v3 (Allows you to use S3 storage with AWS SDK v3)
league/flysystem suggests installing spatie/flysystem-dropbox (Allows you to use Dropbox storage)
league/flysystem suggests installing srmklive/flysystem-dropbox-v2 (Allows you to use Dropbox storage for PHP 5 applications)
league/flysystem suggests installing league/flysystem-cached-adapter (Flysystem adapter decorator for metadata caching)
league/flysystem suggests installing ext-ftp (Allows you to use FTP server storage)
league/flysystem suggests installing league/flysystem-sftp (Allows you to use SFTP server storage via phpseclib)
league/flysystem suggests installing league/flysystem-ziparchive (Allows you to use ZipArchive adapter)
Package mschop/noteephp is abandoned, you should avoid using it. Use mschop/notee instead.
Writing lock file
Generating autoload files
21 packages you are using are looking for funding.
Use the `composer fund` command to find out more!

<?php
use League\Flysystem\Filesystem as FlyFilesystem;
use League\Flysystem\Adapter\Local as FlyLocal;
use League\Flysystem\FileExistsException as FlyFileExistsException;

require_once __DIR__ . '/vendor/autoload.php';

//ファイルを読み込み表示
$fs = new FlyFilesystem(new FlyLocal(__DIR__));
$content = $fs->read('sample.txt');
print($content);

//ファイル書き込み(ファイルがなければ新規作成あれば更新)
try {
    $content = $fs->put('sample-white.txt', 'white word');
  } catch (FlyFileNotFoundException $e) {
    throw $e;
  }

hello world