John Davidson

Message:

PHP 8 changes how the "open" of a ZIP archive works and it is noted that:

Using empty file as ZipArchive is deprecated. Libzip 1.6.0 do not accept empty files as valid zip archives any longer.

In the test code below the opening of the ZIP file named $backupzip works without error but the opening of the ZIP file names $invoicezip fails with the error:

Deprecated: ZipArchive::open(): Using empty file as ZipArchive is deprecated on line 12

<?php

declare(strict_types=1);

ini_set('display_errors','1');ini_set('display_startup_errors','1');error_reporting(E_ALL);

    

define('BACKUPDIR','E:\Database_Backups\\');

$backupfile = BACKUPDIR . date('Ymd') . '.zip';

$temp_file  = tempnam(sys_get_temp_dir(),'AW');



$backupzip  = new ZipArchive();

$invoicezip = new ZipArchive();



$backupzip->open($backupfile,ZipArchive::CREATE);  // <<<--- this works

$invoicezip->open($temp_file,ZipArchive::CREATE);  // <<<--- this fails

---

My Answer:
ZipArchive class is used with temporary files. In previous versions of PHP, you would typically create a ZipArchive object, add files to it, and then save the zip file to a specific location on the server.

With PHP 8, you can now use temporary files to create and manipulate zip archives without having to save them to a specific location on the server. This can be useful for scenarios where you need to generate a zip file on-the-fly and serve it directly to the user without saving it to disk.

Here's an example of how you can use temporary files with ZipArchive in PHP 8:

php
// Create a new ZipArchive object
$zip = new ZipArchive();

// Create a temporary file to store the zip archive
$tempFile = tempnam(sys_get_temp_dir(), 'zip');

// Open the temporary file for writing
$zip->open($tempFile, ZipArchive::CREATE);

// Add files to the zip archive
$zip->addFile('file1.txt');
$zip->addFile('file2.txt');

// Close the zip archive
$zip->close();

// Serve the zip archive to the user
header('Content-Type: application/zip');
header('Content-Disposition: attachment; filename="archive.zip"');
readfile($tempFile);

// Delete the temporary file
unlink($tempFile);


In this example, we create a temporary file using the `tempnam()` function and open it with the `ZipArchive::open()` method. We then add files to the zip archive using the `ZipArchive::addFile()` method, close the archive, and serve it to the user using the `readfile()` function. Finally, we delete the temporary file using the `unlink()` function.

Using temporary files with ZipArchive in PHP 8 allows you to efficiently generate and serve zip archives without the need to save them to disk, making your code more streamlined and secure.