How to [recursively] Zip a directory in PHP?

Directory is something like:

home/
    file1.html
    file2.html
Another_Dir/
    file8.html

    Sub_Dir/
        file19.html

I am using the same PHP Zip class used in PHPMyAdmin http://trac.seagullproject.org/browser/branches/0.6-bugfix/lib/other/Zip.php . I'm not sure how to zip a directory rather than just a file. Here's what I have so far:

$aFiles = $this->da->getDirTree($target);
/* $aFiles is something like, path => filetime
Array
(

    [home] => 
    [home/file1.html] => 1251280379
    [home/file2.html] => 1251280377
    etc...
)

*/
$zip = & new Zip();
foreach( $aFiles as $fileLocation => $time ){
    $file = $target . "/" . $fileLocation;

    if ( is_file($file) ){
        $buffer = file_get_contents($file);
        $zip->addFile($buffer, $fileLocation);
    }
}
THEN_SOME_PHP_CLASS::toDownloadData($zip); // this bit works ok

but when I try to unzip the corresponding downloaded zip file I get "operation not permitted"

This error only happens when I try to unzip on my mac, when I unzip through the command line the file unzips ok. Do I need to send a specific content type on download, currently 'application/zip'

Answer

Here is a simple function that can compress any file or directory recursively, only needs the zip extension to be loaded.

function Zip($source, $destination)
{
    if (!extension_loaded('zip') || !file_exists($source)) {
        return false;
    }


    $zip = new ZipArchive();
    if (!$zip->open($destination, ZIPARCHIVE::CREATE)) {
        return false;
    }

    $source = str_replace('\\', '/', realpath($source));

    if (is_dir($source) === true)
    {
        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);


        foreach ($files as $file)
        {
            $file = str_replace('\\', '/', $file);

            // Ignore "." and ".." folders
            if( in_array(substr($file, strrpos($file, '/')+1), array('.', '..')) )
                continue;

            $file = realpath($file);


            if (is_dir($file) === true)
            {
                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
            }
            else if (is_file($file) === true)
            {
                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
            }
        }

    }
    else if (is_file($source) === true)
    {
        $zip->addFromString(basename($source), file_get_contents($source));
    }

    return $zip->close();
}

Call it like this:

Zip('/folder/to/compress/', './compressed.zip');