PHP Zip files and directory

Sometimes you require zipping a file or even an entire directory at your server with PHP. The best way is to use ZipArchive class to do it. If you have PHP 5.2 or later version installed on your server and if zip library is enabled then ZipArchive class will be available to you. This class has lots of useful member function which makes easier in zipping files.

How to use ZipArchive class in PHP

Like any other classes first you have to create an object of ZipArchive class to use its public member functions.
$zip-> new ZipArchive();

PHP create zip file

After creating an object of ZipArchive class now you can create a new zip file. The member function open() is used to create a new zip file or to open an existing zip archive.

$filename='backup.zip';
if(($zip->open($filename, ZipArchive::CREATE))!==true){ die('Error: Unable to create zip file');}

Please remember if the file 'backup.zip' already exists this function will open the existing file.

Adding files inside a zip archive

To add a new file inside a zip archive use member function
addFile('realname',['saveAs']).
As you can see this function takes two arguments, one is the 'realname', i.e. name of the file to be added and other is the optional argument 'saveAs'. The 'saveAs' parameter is the name of the file by which you want to add it inside the zip archive. If you omit this parameter the file will be saved by its real name. The importance of this parameter can be explained by the following example.

<?php
//File to be added inside zip archive.
$file='/home/domain/public_html/example.txt';
//Open zip archive.
$zip-> new ZipArchive();
if(($zip->open('test.zip', ZipArchive::CREATE))!==true){ die('Error: Unable to create zip file');}
//Add file by its real name.
$zip->addFile($file);
//Add the same file with different name say, 'newname.txt'.
$zip->addFile($file,'newname.txt');
//Close zip archive.
$zip->close();
//Download zip file.
header("Location: test.zip");
exit;
?>

After running this script you will be prompted to download test.zip file. Save this file at your computer desktop and open it. You will see the file 'newname.txt' is at the root of your zip archive while the file 'example.txt' resides inside directories '/home/domain/public_html/'.

Closing an open zip archive

In the above example I use a new member function close(). This function is used to close an open zip archive. Although PHP will automatically close it at the end of the script but you should do it yourself.

Zip a directory in PHP

You can insert a complete directory, all files and subdirectory in it into a zip archive by PHP. The most efficient way is to use a recursive program to do it. Below, I write a recursive function which can zip a directory.

function recurse_zip($src,&$zip,$path_length) {
        $dir = opendir($src);
        while(false !== ( $file = readdir($dir)) ) {
            if (( $file != '.' ) && ( $file != '..' )) {
                if ( is_dir($src . '/' . $file) ) {
                    recurse_zip($src . '/' . $file,$zip,$path_length);
                }
                else {
                    $zip->addFile($src . '/' . $file,substr($src . '/' . $file,$path_length));
                }
            }
        }
        closedir($dir);
}
//Call this function with argument = absolute path of file or directory name.
function compress($src)
{
        if(substr($src,-1)==='/'){$src=substr($src,0,-1);}
        $arr_src=explode('/',$src);
        $filename=end($src);
        unset($arr_src[count($arr_src)-1]);
        $path_length=strlen(implode('/',$arr_src).'/');
        $f=explode('.',$filename);
        $filename=$f[0];
        $filename=(($filename=='')? 'backup.zip' : $filename.'.zip');}
        $zip = new ZipArchive;
        $res = $zip->open($filename, ZipArchive::CREATE);
        if($res !== TRUE){
                echo 'Error: Unable to create zip file';
                exit;}
        if(is_file($src)){$zip->addFile($src,substr($src,$path_length));}
        else{
                if(!is_dir($src)){
                     $zip->close();
                     @unlink($filename);
                     echo 'Error: File not found';
                     exit;}
        recurse_zip($src,$zip,$path_length);}
        $zip->close();
        header("Location: $filename");
        exit;
}

$filename=(($filename=='')? 'backup.zip' : $filename.'.zip');}
$yourpath='newfolder/';//or $yourpath='../newfolder/';
$filename=$yourpath.$filename;
$zip = new ZipArchive;