Zip a folder and all subfolders in it

zipit.php

<?php
/**
 * Zip a folder
 *
 * @param string $src path to folder path/folder
 * @param string $dest destination name path/folder.zip
 * @see http://stackoverflow.com/questions/4914750/how-to-zip-a-whole-folder-using-php
 */
function zipit( $src, $dest = null ) {
	
	// Get real path for our folder
	$path = realpath( $src );

	if ( ! $dest ) {
		$dest = $src . '.zip';
	}

	// Initialize archive object
	$zip = new ZipArchive();
	$zip->open( $dest, ZipArchive::CREATE | ZipArchive::OVERWRITE);

	// Create recursive directory iterator
	/** @var SplFileInfo[] $files */
	$files = new RecursiveIteratorIterator(
		new RecursiveDirectoryIterator( $path ),
		RecursiveIteratorIterator::LEAVES_ONLY
	);	

	foreach ( $files as $name => $file ) {
		// Skip directories (they would be added automatically)
		if ( ! $file->isDir() ) {
			// Get real and relative path for current file
			$file_path = $file->getRealPath();
			$relative_path = substr( $file_path, strlen( $path ) + 1);

			// Add current file to archive
			$zip->addFile( $file_path, $relative_path );
		}
	}

	// Zip archive will be created only after closing object
	$zip->close();
}