PHP ZipArchive Tutorial: How to Modify File Timestamps Inside ZIP Archives

Introduction

In PHP development, working with ZIP archives using the ZipArchive class is very common. Sometimes, there is a need to modify the timestamps of files inside these archives to meet specific requirements. This article explains how to achieve this using ZipArchive.

Overview of ZipArchive

ZipArchive is a built-in PHP class designed for creating, opening, reading, and modifying ZIP files. It offers various methods to manage archive contents efficiently.

How to Modify File Timestamps Inside a ZIP Archive

First, open the target ZIP archive with the ZipArchive class:

$zip = new ZipArchive();
$zipFile = 'path/to/your/zip/file.zip';
if ($zip->open($zipFile) === true) {
    // Continue with operations
}

Then, use the statIndex method to retrieve detailed info about a file at a given index, including its timestamp:

$fileIndex = 0; // File index inside the archive
$fileInfo = $zip->statIndex($fileIndex);
$lastModifiedTime = $fileInfo['mtime'];

Modify the timestamp, for example, set it to the current time:

$lastModifiedTime = time();

Apply the new timestamp to the file using the setModificationTime method:

$zip->setModificationTime($fileIndex, $lastModifiedTime);

Finally, close the archive to save changes:

$zip->close();

Example Code

Here is a complete example demonstrating how to update the timestamp of the first file inside a ZIP archive:

$zip = new ZipArchive();
$zipFile = 'path/to/your/zip/file.zip';
if ($zip->open($zipFile) === true) {
    $fileIndex = 0;
    $fileInfo = $zip->statIndex($fileIndex);
    $lastModifiedTime = $fileInfo['mtime'];
    
    $lastModifiedTime = time();
    
    $zip->setModificationTime($fileIndex, $lastModifiedTime);
    $zip->close();
}

This code updates the timestamp of the file at index 0 to the current time.

Conclusion

Using PHP's ZipArchive class, modifying file timestamps inside ZIP archives is straightforward. This article provided a clear process and example to help you customize file times within compressed files as needed.