$x = pack($format, $original); ok($original == unpack($format, $x), 'reversible unpack'); $x = external_platform_pack($format, $original); ok($original == unpack($format, $x), 'unpack from platform-specific source'); $x = pack($format, $original); ok($original == external_platform_unpack($format, $x), 'pack to platform-specific source');