December 03, 2018

Create a Zip File in PHP

In this post you will learn how to store uploaded files in ZipArchive with working demo and source code. We will use zip extension of PHP. This is included in PHP's default extensions bundle.

Create a Zip File in PHP
Demo Download

What is ZipArchive?

ZipArchive is a file format which allows you to compress and store multiple files into one single file. With ZipArchive you can reduce the files size and easily share one single file. You can compress various types of files with ZipArchive such as text files, images, videos, and many others. Learn in this post how to create a zip file in PHP using PHP ZipArchive class.

Files we are going to create for this post:

  • index.php: The HTML form to upload files for PHP zip file creation. 
  • process-zip.php: PHP script code to create a zip file of uploaded files.
  • style.css: CSS styles of index.php.


Create an HTML Form to Upload Files for Zip File Creation

In our index.php we create a form with a file input field to upload files. For demo purposes we will allow only images and text files. We will compress these uploaded files on server side and create a zip file.

index.php

<!DOCTYPE html>
<html>
    <head>
        <title>Create a Zip File in PHP - Demo</title>
        <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"/>
        <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet"/>
        <link rel="stylesheet" href="css/style.css" />
    </head>
    <body>
        <div class="container">
            <div class="my-4">
                <form action="process-zip.php" method="POST" enctype="multipart/form-data">
                    <div class="row">
                        <div class="col-6">
                            <input type="file" class="file-input" name="zip_files[]" multiple="multiple"/>
                        </div>
                        <div class="col-6 text-right">
                            <button type="submit" class="btn btn-blue">
                                <i class="fa fa-upload"></i> 
                                Upload
                            </button>
                        </div>
                    </div>
                </form>
            </div>
        </div>
    </body>
</html>

How to Create a Zip Archive File in PHP

In our process-zip.php we create a zip file of uploaded files. We load the PHP zip extension if it is not already loaded, add uploaded files to zip file. After the zip file is created we initiate a download with PHP headers. This is how this script is working:

  • Check if there are any files uploaded.
  • Check if PHP zip extension is loaded, if extension is not loaded then load the extension on runtime. Load zip.dll  for windows and zip.so for Unix-based systems.
  • Create an instance of zip file using PHP ZipArchive class.
  • Set a filename for our zip file and file path to store the zip file. Create an array of allowed file type extensions.
  • Create and open zip file with create and overwrite flags.
  • Loop through all uploaded files and check if each file is less than 2MB in size and has the extension from $allowed_files array.
  •  Add each file to zip archive.
  • Close the zip archive instance.
  • Set PHP headers for download and initiate download for the zip file we created.
  • Finally, delete the file after download. 

process-zip.php 

<?php
if(!empty($_FILES)){
    // If zip extension is not loaded then load it in runtime
    if(!extension_loaded('zip')){
        if(strtoupper(substr(PHP_OS, 0,3)) === 'WIN'){
            load_lib('zip.dll');
        }else{
            load_lib('zip.so');
        }
    }
    
    // Initialize zip archive
    $zip = new ZipArchive();
    $filename = time() . '_zip_file.zip';
    $zip_file = __DIR__  .'/'. $filename;
    $allowed_files = ['pdf', 'jpg', 'jpeg', 'gif', 'png', 'txt'];

    if($zip->open($zip_file, ZIPARCHIVE::CREATE|ZIPARCHIVE::OVERWRITE)){
        // Loop all files and add them to zip
        for($i = 0; $i < count($_FILES['zip_files']['name']); $i++){
            $extension = pathinfo($_FILES['zip_files']['name'][$i],PATHINFO_EXTENSION);
            $file_size_kb = number_format($_FILES['zip_files']['size'][$i] / 1024, 2);

            //If uploaded file type is in allowed filed types then add it to zip
            if(in_array($extension,$allowed_files) && $file_size_kb < 2048 && $i <= 15){
                $zip->addFile($_FILES['zip_files']['tmp_name'][$i],$_FILES['zip_files']['name'][$i]);
            }
        }
        $zip->close();
    }

    // If file exists then set download headers
    if(file_exists($zip_file)){
        ob_start();
        
        header('Content-Type: application/octet-stream');
        header('Content-Transfer-Encoding: binary'); 
        header('Content-Disposition: attachment; filename="' . $filename . '";');
        header('Content-Length: ' . filesize($zip_file));
        
        ob_clean();

        readfile($zip_file);
        unlink($zip_file);
    }
}

Add CSS Styles

Add CSS styles for whole page and files upload form.

style.css

*{
    box-sizing: border-box;
}
html,body{
    margin: 0;
    padding: 0;
}
body{
    background-color: #f6f6f6;
    font-family: "Segoe UI", "Roboto", "Helvetica", sans-serif;
    font-size: 15px;
    font-weight: normal;
    font-style: normal;
    line-height: 1.5;
}
.container{
    width: 100%;
    max-width: 1140px;
    margin-right: auto;
    margin-left: auto;
    padding-right: 15px;
    padding-left: 15px;
}
.my-4{
    margin-top: 1rem;
    margin-bottom: 1rem;
}
.text-right{
    text-align: right;
}
.row{
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;
    margin-right: -15px;
    margin-left: -15px;
}
.col-6{
    width: 100%;
    min-height: 1px;
    padding-right: 15px;
    padding-left: 15px;
    -webkit-box-flex: 0;
    -ms-flex: 0 0 50%;
    flex: 0 0 50%;
    max-width: 50%;
}
.btn{
    display: inline-block;
    padding: 5px 10px;
    cursor: pointer;
    font: inherit;
}
.btn-blue{
    background-color: #006699;
    border: 1px solid #2b7cab;
    color: #ffffff;
}
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