wp_zip_file_is_valid

WordPress Version: 4.4

/**
 * Determines whether the given file is a valid ZIP file.
 *
 * This function does not test to ensure that a file exists. Non-existent files
 * are not valid ZIPs, so those will also return false.
 *
 * @since 6.4.4
 *
 * @param string $file Full path to the ZIP file.
 * @return bool Whether the file is a valid ZIP file.
 */
function wp_zip_file_is_valid($file)
{
    /** This filter is documented in wp-admin/includes/file.php */
    if (class_exists('ZipArchive', false) && apply_filters('unzip_file_use_ziparchive', true)) {
        $archive = new ZipArchive();
        $archive_is_valid = $archive->open($file, ZipArchive::CHECKCONS);
        if (true === $archive_is_valid) {
            $archive->close();
            return true;
        }
    }
    // Fall through to PclZip if ZipArchive is not available, or encountered an error opening the file.
    require_once ABSPATH . 'wp-admin/includes/class-pclzip.php';
    $archive = new PclZip($file);
    $archive_is_valid = is_array($archive->properties());
    return $archive_is_valid;
}