:spoiler: /n./ [Usenet] 1. A remark which reveals important plot elements from books or movies, thus denying the reader (of the article) the proper suspense when reading the book or watching the movie. 2. Any remark which telegraphs the solution of a problem or puzzle, thus denying the reader the pleasure of working out the correct answer (see also {interesting}). Either sense readily forms compounds like `total spoiler', `quasi-spoiler' and even `pseudo-spoiler'.
By convention, articles which are spoilers in either sense should contain the word `spoiler' in the Subject: line, or guarantee via various tricks that the answer appears only after several screens-full of warning, or conceal the sensitive information via {rot13}, or some combination of these techniques.
:sponge: /n./ [Unix] A special case of a {filter} that reads its entire input before writing any output; the canonical example is a sort utility. Unlike most filters, a sponge can conveniently overwrite the input file with the output data stream. If a file system has versioning (as ITS did and VMS does now) the sponge/filter distinction loses its usefulness, because directing filter output would just write a new version. See also {slurp}.
:spool: /vi./ [from early IBM `Simultaneous Peripheral Operation On-Line', but this acronym is widely thought to have been contrived for effect] To send files to some device or program (a `spooler') that queues them up and does something useful with them later. Without qualification, the spooler is the `print spooler' controlling output of jobs to a printer; but the term has been used in connection with other peripherals (especially plotters and graphics devices) and occasionally even for input devices. See also {demon}.
:spool file: /n./ Any file to which data is {spool}ed to await the next stage of processing. Especially used in circumstances where spooling the data copes with a mismatch between speeds in two devices or pieces of software. For example, when you send mail under Unix, it's typically copied to a spool file to await a transport {demon}'s attentions. This is borderline techspeak.
:square tape: /n./ Mainframe magnetic tape cartridges for use with IBM 3480 or compatible tape drives; or QIC tapes used on workstations and micros. The term comes from the square (actually rectangular) shape of the cartridges; contrast {round tape}.
:squirrelcide: /n./ [common on Usenet's comp.risks newsgroup.] (alt. `squirrelicide') What all too frequently happens when a squirrel decides to exercise its species's unfortunate penchant for shorting out power lines with their little furry bodies. Result: one dead squirrel, one down computer installation. In this situation, the computer system is said to have been squirrelcided.
:stack: /n./ The set of things a person has to do in the future. One speaks of the next project to be attacked as having risen to the top of the stack. "I'm afraid I've got real work to do, so this'll have to be pushed way down on my stack." "I haven't done it yet because every time I pop my stack something new gets pushed." If you are interrupted several times in the middle of a conversation, "My stack overflowed" means "I forget what we were talking about." The implication is that more items were pushed onto the stack than could be remembered, so the least recent items were lost. The usual physical example of a stack is to be found in a cafeteria: a pile of plates or trays sitting on a spring in a well, so that when you put one on the top they all sink down, and when you take one off the top the rest spring up a bit. See also {push} and {pop}.
At MIT, {pdl} used to be a more common synonym for {stack} in all these contexts, and this may still be true. Everywhere else {stack} seems to be the preferred term. {Knuth} ("The Art of Computer Programming", second edition, vol. 1, p. 236) says:
Many people who realized the importance of stacks and queues independently have given other names to these structures: stacks have been called push-down lists, reversion storages, cellars, nesting stores, piles, last-in-first-out ("LIFO") lists, and even yo-yo lists!