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live data


live data: n. 1. Data that is written to be interpreted and takes
   over program flow when triggered by some un-obvious operation, such
   as viewing it.  One use of such hacks is to break security.  For
   example, some smart terminals have commands that allow one to
   download strings to program keys; this can be used to write live
   data that, when listed to the terminal, infects it with a
   security-breaking virus that is triggered the next time a
   hapless user strikes that key.  For another, there are some
   well-known bugs in vi that allow certain texts to send
   arbitrary commands back to the machine when they are simply viewed.
   2. In C code, data that includes pointers to function hooks
   (executable code).  3. An object, such as a trampoline, that is
   constructed on the fly by a program and intended to be executed as
   code.  4. Actual real-world data, as opposed to `test data'.
   For example, "I think I have the record deletion module
   finished."  "Have you tried it out on live data?"  This usage usually
   carries the connotation that live data is more fragile and must not
   be corrupted, or bad things will happen.  So a more appropriate
   response to the above claim might be: "Well, make sure it works
   perfectly before we throw live data at it."  The implication here
   is that record deletion is something pretty significant, and a
   haywire record-deletion module running amok on live data would
   probably cause great harm.