WordPress at a glance
function is not described

_unzip_file_ziparchive() WP 3.0.0

This function should not be called directly, use unzip_file instead. Attempts to unzip an archive using the ZipArchive class. Assumes that WP_Filesystem() has already been called and set up.

  • See: unzip_file
  • Global. WP_Filesystem_Base. $wp_filesystem Subclass

No Hooks.

Return

Mixed. WP_Error on failure, True on success

Usage

_unzip_file_ziparchive( $file, $to, $needed_dirs );
$file(string) (required)
Full path and filename of zip archive
$to(string) (required)
Full path on the filesystem to extract archive to
$needed_dirs(array)
A partial list of required folders needed to be created.
Default: array()

Code of unzip file ziparchive: wp-admin/includes/file.php VER 5.0.3

<?php
function _unzip_file_ziparchive($file, $to, $needed_dirs = array() ) {
	global $wp_filesystem;

	$z = new ZipArchive();

	$zopen = $z->open( $file, ZIPARCHIVE::CHECKCONS );
	if ( true !== $zopen )
		return new WP_Error( 'incompatible_archive', __( 'Incompatible Archive.' ), array( 'ziparchive_error' => $zopen ) );

	$uncompressed_size = 0;

	for ( $i = 0; $i < $z->numFiles; $i++ ) {
		if ( ! $info = $z->statIndex($i) )
			return new WP_Error( 'stat_failed_ziparchive', __( 'Could not retrieve file from archive.' ) );

		if ( '__MACOSX/' === substr($info['name'], 0, 9) ) // Skip the OS X-created __MACOSX directory
			continue;

		// Don't extract invalid files:
		if ( 0 !== validate_file( $info['name'] ) ) {
			continue;
		}

		$uncompressed_size += $info['size'];

		if ( '/' === substr( $info['name'], -1 ) ) {
			// Directory.
			$needed_dirs[] = $to . untrailingslashit( $info['name'] );
		} elseif ( '.' !== $dirname = dirname( $info['name'] ) ) {
			// Path to a file.
			$needed_dirs[] = $to . untrailingslashit( $dirname );
		}
	}

	/*
	 * disk_free_space() could return false. Assume that any falsey value is an error.
	 * A disk that has zero free bytes has bigger problems.
	 * Require we have enough space to unzip the file and copy its contents, with a 10% buffer.
	 */
	if ( wp_doing_cron() ) {
		$available_space = @disk_free_space( WP_CONTENT_DIR );
		if ( $available_space && ( $uncompressed_size * 2.1 ) > $available_space )
			return new WP_Error( 'disk_full_unzip_file', __( 'Could not copy files. You may have run out of disk space.' ), compact( 'uncompressed_size', 'available_space' ) );
	}

	$needed_dirs = array_unique($needed_dirs);
	foreach ( $needed_dirs as $dir ) {
		// Check the parent folders of the folders all exist within the creation array.
		if ( untrailingslashit($to) == $dir ) // Skip over the working directory, We know this exists (or will exist)
			continue;
		if ( strpos($dir, $to) === false ) // If the directory is not within the working directory, Skip it
			continue;

		$parent_folder = dirname($dir);
		while ( !empty($parent_folder) && untrailingslashit($to) != $parent_folder && !in_array($parent_folder, $needed_dirs) ) {
			$needed_dirs[] = $parent_folder;
			$parent_folder = dirname($parent_folder);
		}
	}
	asort($needed_dirs);

	// Create those directories if need be:
	foreach ( $needed_dirs as $_dir ) {
		// Only check to see if the Dir exists upon creation failure. Less I/O this way.
		if ( ! $wp_filesystem->mkdir( $_dir, FS_CHMOD_DIR ) && ! $wp_filesystem->is_dir( $_dir ) ) {
			return new WP_Error( 'mkdir_failed_ziparchive', __( 'Could not create directory.' ), substr( $_dir, strlen( $to ) ) );
		}
	}
	unset($needed_dirs);

	for ( $i = 0; $i < $z->numFiles; $i++ ) {
		if ( ! $info = $z->statIndex($i) )
			return new WP_Error( 'stat_failed_ziparchive', __( 'Could not retrieve file from archive.' ) );

		if ( '/' == substr($info['name'], -1) ) // directory
			continue;

		if ( '__MACOSX/' === substr($info['name'], 0, 9) ) // Don't extract the OS X-created __MACOSX directory files
			continue;

		// Don't extract invalid files:
		if ( 0 !== validate_file( $info['name'] ) ) {
			continue;
		}

		$contents = $z->getFromIndex($i);
		if ( false === $contents )
			return new WP_Error( 'extract_failed_ziparchive', __( 'Could not extract file from archive.' ), $info['name'] );

		if ( ! $wp_filesystem->put_contents( $to . $info['name'], $contents, FS_CHMOD_FILE) )
			return new WP_Error( 'copy_failed_ziparchive', __( 'Could not copy file.' ), $info['name'] );
	}

	$z->close();

	return true;
}