1. Something passed between routines or programs that enables the receiver to perform some operation a capability ticket or opaque identifier. Especially used of small data objects that contain data encoded in a strange or intrinsically machine-dependent way. E.g. on non-Unixoperating systems with a non-byte-stream model of files, the result of "ftell" may be a magic cookie rather than a byte offset it can be passed to "fseek", but not operated on in any meaningful way. The phrase "it hands you a magic cookie" means it returns a result whose contents are not defined but which can be passed back to the same or some other program later. 2. An in-band code for changing graphic rendition (e.g. inverse video or underlining) or performing other control functions. Some older terminals would leave a blank on the screen corresponding to mode-change magic cookies this was also called a glitch (or occasionally a "turd" compare {mouse droppings}). See also cookie. [Jargon File] (1995-01-25)
