unzip_file() │ WP 2.5.0

Unzips a specified ZIP file to a location on the Filesystem via the WordPress Filesystem Abstraction. Assumes that WP_Filesystem() has already been called and set up. Does not extract a root-level __MACOSX directory, if present.

Assumes that WP_Filesystem() has already been called and set up. Does not extract a root-level __MACOSX directory, if present.

Attempts to increase the PHP memory limit to 256M before uncompressing. However, the most memory required shouldn't be much larger than the archive itself.

Uses: _unzip_file_pclzip()
Hooks from the function

Return

true|WP_Error. True on success, WP_Error on failure.

Usage

unzip_file( $file, $to );
$file(string) (required)
Full path and filename of ZIP archive.
$to(string) (required)
Full path on the filesystem to extract archive to.

Examples

1

#1 Basic example

Showing how to unzip the contents of a .zip file, that resides in the WordPress upload directory, to the same destination.

WP_Filesystem();
$destination = wp_upload_dir();
$destination_path = $destination['path'];
$unzipfile = unzip_file( "{$destination_path}/filename.zip", $destination_path );

if ( $unzipfile ) {
	echo 'Successfully unzipped the file!';       
}
else {
	echo 'There was an error unzipping the file.';       
}
0

#2 Example of unzipping an archive with unzip_file()

Although this function requires initialization of the file system API, it is not a method of the $wp_filesystem object, so it must be passed parameters with $wp_filesystem in mind.

The first parameter, $file, must be the absolute path to the file (on the server), and the parameter $to must point to the absolute path of the WordPress file system.

// even in the admin panel, check if the function is defined
if ( ! function_exists( 'unzip_file' ) ) {
	require_once ABSPATH . 'wp-admin/includes/file.php';
}

// and the global variable must contain an object
global $wp_filesystem;
if ( ! $wp_filesystem ) {
	// but if it does not, this function corrects the situation
	WP_Filesystem();
}
define( 'MY_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );

// this variable must already have been set when initializing the file system
global $wp_filesystem;

// remote path to the file system
$plugin_path = str_replace( ABSPATH, $wp_filesystem->abspath(), MY_PLUGIN_DIR );

// the RIGHT way to use the function
$file = MY_PLUGIN_DIR . '/plugin-file.zip';
$to   = $plugin_path;

$result = unzip_file( $file, $to );

if( $result === true ){
	// OK: the archive is unpacked
}

// the wrong way to use the function
// $to cannot be a direct path to the folder, otherwise the FTP and SSH methods remain inoperable
$file = MY_PLUGIN_DIR . '/plugin-file.zip';
$to   = MY_PLUGIN_DIR;

unzip_file( $file, $to );

// the wrong way to use the function
// If $file is not a "direct" absolute path,
// then users who do not use FTP and SSH methods are left out
$file = $plugin_path . '/plugin-file.zip';
$to   = $plugin_path;

unzip_file( $file, $to );

Notes

  • Global. WP_Filesystem_Base. $wp_filesystem WordPress filesystem subclass.

Changelog

Since 2.5.0 Introduced.

unzip_file() code WP 6.5.2

wp-admin/includes/file.php 
function unzip_file( $file, $to ) {
	global $wp_filesystem;

	if ( ! $wp_filesystem || ! is_object( $wp_filesystem ) ) {
		return new WP_Error( 'fs_unavailable', __( 'Could not access filesystem.' ) );
	}

	// Unzip can use a lot of memory, but not this much hopefully.
	wp_raise_memory_limit( 'admin' );

	$needed_dirs = array();
	$to          = trailingslashit( $to );

	// Determine any parent directories needed (of the upgrade directory).
	if ( ! $wp_filesystem->is_dir( $to ) ) { // Only do parents if no children exist.
		$path = preg_split( '![/\\\]!', untrailingslashit( $to ) );
		for ( $i = count( $path ); $i >= 0; $i-- ) {
			if ( empty( $path[ $i ] ) ) {
				continue;
			}

			$dir = implode( '/', array_slice( $path, 0, $i + 1 ) );
			if ( preg_match( '!^[a-z]:$!i', $dir ) ) { // Skip it if it looks like a Windows Drive letter.
				continue;
			}

			if ( ! $wp_filesystem->is_dir( $dir ) ) {
				$needed_dirs[] = $dir;
			} else {
				break; // A folder exists, therefore we don't need to check the levels below this.
			}
		}
	}

	/**
	 * Filters whether to use ZipArchive to unzip archives.
	 *
	 * @since 3.0.0
	 *
	 * @param bool $ziparchive Whether to use ZipArchive. Default true.
	 */
	if ( class_exists( 'ZipArchive', false ) && apply_filters( 'unzip_file_use_ziparchive', true ) ) {
		$result = _unzip_file_ziparchive( $file, $to, $needed_dirs );
		if ( true === $result ) {
			return $result;
		} elseif ( is_wp_error( $result ) ) {
			if ( 'incompatible_archive' !== $result->get_error_code() ) {
				return $result;
			}
		}
	}
	// Fall through to PclZip if ZipArchive is not available, or encountered an error opening the file.
	return _unzip_file_pclzip( $file, $to, $needed_dirs );
}

File system (create delete files folders)

File system (WP_Filesystem)