The unzip.php program, shown in Example, extracts files from a ZIP archive. It uses the pc_mkdir_parents( ) function. The program also requires PHP's zip extension to be installed. You can find documentation on the zip extension at http://www.php.net/zip . This program takes a few arguments on the command line. The first is the name of the ZIP archive it should unzip. By default, it unzips all files in the archive. If additional command-line arguments are supplied, it only unzips files whose name matches any of those arguments. The full path of the file inside the ZIP archive must be given. If turtles.html is in the ZIP archive inside the animals directory, unzip.php must be passed animals/turtles.html , not just turtles.html , to unzip the file. Directories are stored as 0-byte files inside ZIP archives, so unzip.php doesn't try to create them. Instead, before it creates any other file, it uses pc_mkdir_parents( ) to create all directories that are par...