The Jargon File, Version 2.9.10, 01 Jul 1992

Part 36

Chapter 36 3,596 words Public domain Markdown

:say: vt. 1. To type to a terminal. "To list a directory verbosely, you have to say `ls -l'." Tends to imply a {newline}-terminated command (a `sentence'). 2. A computer may also be said to `say' things to you, even if it doesn't have a speech synthesizer, by displaying them on a terminal in response to your commands. Hackers find it odd that this usage confuses {mundane}s.

:scag: vt. To destroy the data on a disk, either by corrupting the filesystem or by causing media damage. "That last power hit scagged the system disk." Compare {scrog}, {roach}.

:scanno: n. An error in a document caused by a scanner glitch, analgous to typo or {thinko}.

:schroedinbug: [MIT: from the Schroedinger's Cat thought-experiment in quantum physics] n. A design or implementation bug in a program which doesn't manifest until someone reading source or using the program in an unusual way notices that it never should have worked, at which point the program promptly stops working for everybody until fixed. Though this sounds impossible, it happens; some programs have harbored latent schroedinbugs for years. Compare {heisenbug}, {Bohr bug}, {mandelbug}.

:science-fiction fandom:: n. Another voluntary subculture having a very heavy overlap with hackerdom; most hackers read SF and/or fantasy fiction avidly, and many go to `cons' (SF conventions) or are involved in fandom-connected activities such as the Society for Creative Anachronism. Some hacker jargon originated in SF fandom; see {defenestration}, {great-wall}, {cyberpunk}, {h}, {ha ha only serious}, {IMHO}, {mundane}, {neep-neep}, {Real Soon Now}. Additionally, the jargon terms {cowboy}, {cyberspace}, {de-rezz}, {go flatline}, {ice}, {virus}, {wetware}, {wirehead}, and {worm} originated in SF stories.

:scram switch: [from the nuclear power industry] n. An emergency-power-off switch (see {Big Red Switch}), esp. one positioned to be easily hit by evacuating personnel. In general, this is *not* something you {frob} lightly; these often initiate expensive events (such as Halon dumps) and are installed in a {dinosaur pen} for use in case of electrical fire or in case some luckless {field servoid} should put 120 volts across himself while {Easter egging}. (See also {molly-guard}.)

:scratch: 1. [from `scratchpad'] adj. Describes a data structure or recording medium attached to a machine for testing or temporary-use purposes; one that can be {scribble}d on without loss. Usually in the combining forms `scratch memory', `scratch register', `scratch disk', `scratch tape', `scratch volume'. See {scratch monkey}. 2. [primarily IBM] vt. To delete (as in a file).

:scratch monkey: n. As in "Before testing or reconfiguring, always mount a {scratch monkey}", a proverb used to advise caution when dealing with irreplaceable data or devices. Used to refer to any scratch volume hooked to a computer during any risky operation as a replacement for some precious resource or data that might otherwise get trashed.

This term preserves the memory of Mabel, the Swimming Wonder Monkey, star of a biological research program at the University of Toronto ca. 1986. Mabel was not (so the legend goes) your ordinary monkey; the university had spent years teaching her how to swim, breathing through a regulator, in order to study the effects of different gas mixtures on her physiology. Mabel suffered an untimely demise one day when DEC {PM}ed the PDP-11 controlling her regulator (see also {provocative maintenance}).

It is recorded that, after calming down an understandably irate customer sufficiently to ascertain the facts of the matter, a DEC troubleshooter called up the {field circus} manager responsible and asked him sweetly, "Can you swim?"

Not all the consequences to humans were so amusing; the sysop of the machine in question was nearly thrown in jail at the behest of certain clueless droids at the local `humane' society. The moral is clear: When in doubt, always mount a scratch monkey.

:screw: [MIT] n. A {lose}, usually in software. Especially used for user-visible misbehavior caused by a bug or misfeature. This use has become quite widespread outside MIT.

:screwage: /skroo'*j/ n. Like {lossage} but connotes that the failure is due to a designed-in misfeature rather than a simple inadequacy or a mere bug.

:scribble: n. To modify a data structure in a random and unintentionally destructive way. "Bletch! Somebody's disk-compactor program went berserk and scribbled on the i-node table." "It was working fine until one of the allocation routines scribbled on low core." Synonymous with {trash}; compare {mung}, which conveys a bit more intention, and {mangle}, which is more violent and final.

:scrog: /skrog/ [Bell Labs] vt. To damage, trash, or corrupt a data structure. "The list header got scrogged." Also reported as `skrog', and ascribed to the comic strip "The Wizard of Id". Compare {scag}; possibly the two are related. Equivalent to {scribble} or {mangle}.

:scrool: /skrool/ [from the pioneering Roundtable chat system in Houston ca. 1984; prob. originated as a typo for `scroll'] n. The log of old messages, available for later perusal or to help one get back in synch with the conversation. It was originally called the `scrool monster', because an early version of the roundtable software had a bug where it would dump all 8K of scrool on a user's terminal.

:scrozzle: /skroz'l/ vt. Used when a self-modifying code segment runs incorrectly and corrupts the running program or vital data. "The damn compiler scrozzled itself again!"

:scruffies: n. See {neats vs. scruffies}.

:SCSI: [Small Computer System Interface] n. A bus-independent standard for system-level interfacing between a computer and intelligent devices. Typically annotated in literature with `sexy' (/sek'see/), `sissy' (/sis'ee/), and `scuzzy' (/skuh'zee/) as pronunciation guides --- the last being the overwhelmingly predominant form, much to the dismay of the designers and their marketing people. One can usually assume that a person who pronounces it /S-C-S-I/ is clueless.

:ScumOS: n. Unflattering hackerism for SunOS, the UNIX variant supported on Sun Microsystems's UNIX workstations (see also {sun-stools}), and compare {AIDX}, {terminak}, {Macintrash} {Nominal Semidestructor}, {Open DeathTrap}, {HP-SUX}. Despite what this term might suggest, Sun was founded by hackers and still enjoys excellent relations with hackerdom; usage is more often in exasperation than outright loathing.

:search-and-destroy mode: n. Hackerism for the search-and-replace facility in an editor, so called because an incautiously chosen match pattern can cause {infinite} damage.

:second-system effect: n. (sometimes, more euphoniously, `second-system syndrome') When one is designing the successor to a relatively small, elegant, and successful system, there is a tendency to become grandiose in one's success and design an {elephantine} feature-laden monstrosity. The term was first used by Fred Brooks in his classic `The Mythical Man-Month: Essays on Software Engineering' (Addison-Wesley, 1975; ISBN 0-201-00650-2). It described the jump from a set of nice, simple operating systems on the IBM 70xx series to OS/360 on the 360 series. A similar effect can also happen in an evolving system; see {Brooks's Law}, {creeping elegance}, {creeping featurism}. See also {{Multics}}, {OS/2}, {X}, {software bloat}.

This version of the jargon lexicon has been described (with altogether too much truth for comfort) as an example of second-system effect run amok on jargon-1....

:secondary damage: n. When a fatal error occurs (esp. a {segfault}) the immediate cause may be that a pointer has been trashed due to a previous {fandango on core}. However, this fandango may have been due to an *earlier* fandango, so no amount of analysis will reveal (directly) how the damage occurred. "The data structure was clobbered, but it was secondary damage."

By extension, the corruption resulting from N cascaded fandangoes on core is `Nth-level damage'. There is at least one case on record in which 17 hours of {grovel}ling with `adb' actually dug up the underlying bug behind an instance of seventh-level damage! The hacker who accomplished this near-superhuman feat was presented with an award by his fellows.

:security through obscurity: n. A name applied by hackers to most OS vendors' favorite way of coping with security holes --- namely, ignoring them and not documenting them and trusting that nobody will find out about them and that people who do find out about them won't exploit them. This never works for long and occasionally sets the world up for debacles like the {RTM} worm of 1988 (see {Great Worm, the}), but once the brief moments of panic created by such events subside most vendors are all too willing to turn over and go back to sleep. After all, actually fixing the bugs would siphon off the resources needed to implement the next user-interface frill on marketing's wish list --- and besides, if they started fixing security bugs customers might begin to *expect* it and imagine that their warranties of merchantability gave them some sort of *right* to a system with fewer holes in it than a shotgunned Swiss cheese, and *then* where would we be?

Historical note: There are conflicting stories about the origin of this term. It has been claimed that it was first used in the USENET newsgroup in comp.sys.apollo during a campaign to get HP/Apollo to fix security problems in its UNIX-{clone} Aegis/DomainOS (they didn't change a thing). {ITS} fans, on the other hand, say it was coined years earlier in opposition to the incredibly paranoid {Multics} people down the hall, for whom security was everything. In the ITS culture it referred to (1) the fact that that by the time a tourist figured out how to make trouble he'd generally gotten over the urge to make it, because he felt part of the community; and (2) (self-mockingly) the poor coverage of the documentation and obscurity of many commands. One instance of *deliberate* security through obscurity is recorded; the command to allow patching the running ITS system ({altmode} altmode control-R) echoed as $$^D. If you actually typed alt alt ^D, that set a flag which would prevent patching the system even if you later got it right.

:SED: [TMRC, from `Light-Emitting Diode'] /S-E-D/ n. Smoke-emitting diode. A {friode} that lost the war. See {LER}.

:segfault: n.,vi. Syn. {segment}, {seggie}.

:seggie: /seg'ee/ [UNIX] n. Shorthand for {segmentation fault} reported from Britain.

:segment: /seg'ment/ vi. To experience a {segmentation fault}. Confusingly, this is often pronounced more like the noun `segment' than like mainstream v. segment; this is because it is actually a noun shorthand that has been verbed.

:segmentation fault: n. [UNIX] 1. An error in which a running program attempts to access memory not allocated to it and {core dump}s with a segmentation violation error. 2. To lose a train of thought or a line of reasoning. Also uttered as an exclamation at the point of befuddlement.

:segv: /seg'vee/ n.,vi. Yet another synonym for {segmentation fault} (actually, in this case, `segmentation violation').

:self-reference: n. See {self-reference}.

:selvage: /sel'v*j/ [from sewing] n. See {chad} (sense 1).

:semi: /se'mee/ or /se'mi:/ 1. n. Abbreviation for `semicolon', when speaking. "Commands to {grind} are prefixed by semi-semi-star" means that the prefix is `;;*', not 1/4 of a star. 2. A prefix used with words such as `immediately' as a qualifier. "When is the system coming up?" "Semi-immediately." (That is, maybe not for an hour.) "We did consider that possibility semi-seriously." See also {infinite}.

:semi-infinite: n. See {infinite}.

:senior bit: [IBM] n. Syn. {meta bit}.

:server: n. A kind of {daemon} that performs a service for the requester and which often runs on a computer other than the one on which the server runs. A particularly common term on the Internet, which is rife with `name servers', `domain servers', `news servers', `finger servers', and the like.

:SEX: /seks/ [Sun Users' Group & elsewhere] n. 1. Software EXchange. A technique invented by the blue-green algae hundreds of millions of years ago to speed up their evolution, which had been terribly slow up until then. Today, SEX parties are popular among hackers and others (of course, these are no longer limited to exchanges of genetic software). In general, SEX parties are a {Good Thing}, but unprotected SEX can propagate a {virus}. See also {pubic directory}. 2. The rather Freudian mnemonic often used for Sign EXtend, a machine instruction found in the PDP-11 and many other architectures. The RCA 1802 chip used in the early Elf and SuperElf personal computers had a `SEt X register' SEX instruction, but this seems to have had little folkloric impact.

DEC's engineers nearly got a PDP-11 assembler that used the `SEX' mnemonic out the door at one time, but (for once) marketing wasn't asleep and forced a change. That wasn't the last time this happened, either. The author of `The Intel 8086 Primer', who was one of the original designers of the 8086, noted that there was originally a `SEX' instruction on that processor, too. He says that Intel management got cold feet and decreed that it be changed, and thus the instruction was renamed `CBW' and `CWD' (depending on what was being extended). Amusingly, the Intel 8048 (the microcontroller used in IBM PC keyboards) is also missing straight `SEX' but has logical-or and logical-and instructions `ORL' and `ANL'.

The Motorola 6809, used in the U.K.'s `Dragon 32' personal computer, actually had an official `SEX' instruction; the 6502 in the Apple II it competed with did not. British hackers thought this made perfect mythic sense; after all, it was commonly observed, you could (on some theoretical level) have sex with a dragon, but you can't have sex with an apple.

:sex changer: n. Syn. {gender mender}.

:shambolic link: n. A UNIX symbolic link, particularly when it confuses you, points to nothing at all, or results in you ending up in some completely unexpected part of the filesystem....

:shareware: /sheir'weir/ n. {Freeware} (sense 1) for which the author requests some payment, usually in the accompanying documentation files or in an announcement made by the software itself. Such payment may or may not buy additional support or functionality. See also {careware}, {charityware}, {crippleware}, {guiltware}, {postcardware}, and {-ware}; compare {payware}.

:shelfware: /shelfweir/ n. Software purchased on a whim (by an individual user) or in accordance with policy (by a corporation or government agency), but not actually required for any particular use. Therefore, it often ends up on some shelf.

:shell: [orig. {{Multics}} techspeak, widely propagated via UNIX] n. 1. [techspeak] The command interpreter used to pass commands to an operating system; so called because it is the part of the operating system that interfaces with the outside world. 2. More generally, any interface program that mediates access to a special resource or {server} for convenience, efficiency, or security reasons; for this meaning, the usage is usually `a shell around' whatever. This sort of program is also called a `wrapper'.

:shell out: [UNIX] n. To spawn an interactive {subshell} from within a program (e.g., a mailer or editor). "Bang foo runs foo in a subshell, while bang alone shells out."

:shift left (or right) logical: [from any of various machines' instruction sets] 1. vi. To move oneself to the left (right). To move out of the way. 2. imper. "Get out of that (my) seat! You can shift to that empty one to the left (right)." Often used without the `logical', or as `left shift' instead of `shift left'. Sometimes heard as LSH /lish/, from the {PDP-10} instruction set. See {Programmer's Cheer}.

:shim: n. A small piece of data inserted in order to achieve a desired memory alignment or other addressing property. For example, the PDP-11 UNIX linker, in split I&D (instructions and data) mode, inserts a two-byte shim at location 0 in data space so that no data object will have an address of 0 (and be confused with the C null pointer). See also {loose bytes}.

:shitogram: /shit'oh-gram/ n. A *really* nasty piece of email. Compare {nastygram}, {flame}.

:short card: n. A half-length IBM PC expansion card or adapter that will fit in one of the two short slots located towards the right rear of a standard chassis (tucked behind the floppy disk drives). See also {tall card}.

:shotgun debugging: n. The software equivalent of {Easter egging}; the making of relatively undirected changes to software in the hope that a bug will be perturbed out of existence. This almost never works, and usually introduces more bugs.

:showstopper: n. A hardware or (especially) software bug that makes an implementation effectively unusable; one that absolutely has to be fixed before development can go on. Opposite in connotation from its original theatrical use, which refers to something stunningly *good*.

:shriek: n. See {excl}. Occasional CMU usage, also in common use among APL fans and mathematicians, especially category theorists.

:Shub-Internet: /shuhb in't*r-net/ [MUD: from H. P. Lovecraft's evil fictional deity `Shub-Niggurath', the Black Goat with a Thousand Young] n. The harsh personification of the Internet, Beast of a Thousand Processes, Eater of Characters, Avatar of Line Noise, and Imp of Call Waiting; the hideous multi-tendriled entity formed of all the manifold connections of the net. A sect of MUDders worships Shub-Internet, sacrificing objects and praying for good connections. To no avail --- its purpose is malign and evil, and is the cause of all network slowdown. Often heard as in "Freela casts a tac nuke at Shub-Internet for slowing her down." (A forged response often follows along the lines of: "Shub-Internet gulps down the tac nuke and burps happily.") Also cursed by users of {FTP} and {telnet} when the system slows down. The dread name of Shub-Internet is seldom spoken aloud, as it is said that repeating it three times will cause the being to wake, deep within its lair beneath the Pentagon.

:sidecar: n. 1. Syn. {slap on the side}. Esp. used of add-ons for the late and unlamented IBM PCjr. 2. The IBM PC compatibility box that could be bolted onto the side of an Amiga. Designed and produced by Commodore, it broke all of the company's own rules. If it worked with any other peripherals, it was by {magic}.

:SIG: n. The Association for Computing Machinery traditionally sponsors Special Interest Groups in various technical areas; well-known ones include SIGARCH (the Special Interest Group for Computer Architecture) and SIGGRAPH (the Special Interest Group for Computer Graphics). Hackers, not surprisingly, like to overextend this naming convention to less formal associations like SIGBEER (at ACM conferences) and SIGFOOD (at University of Illinois).

:sig block: /sig blok/ [UNIX; often written `.sig' there] n. Short for `signature', used specifically to refer to the electronic signature block that most UNIX mail- and news-posting software will {automagically} append to outgoing mail and news. The composition of one's sig can be quite an art form, including an ASCII logo or one's choice of witty sayings (see {sig quote}, {fool file, the}); but many consider large sigs a waste of {bandwidth}, and it has been observed that the size of one's sig block is usually inversely proportional to one's longevity and level of prestige on the net.

:sig quote: /sig kwoht/ [USENET] n. A maxim, quote, proverb, joke, or slogan embedded in one's {sig block} and intended to convey something of one's philosophical stance, pet peeves, or sense of humor. "Calm down, it's only ones and zeroes."

:sig virus: n. A parasitic {meme} embedded in a {sig block}. There was a {meme plague} or fad for these on USENET in late 1991. Most were equivalents of "I am a .sig virus. Please reproduce me in your .sig block.". Of course, the .sig virus's memetic hook is the giggle value of going along with the gag; this, however, was a self-limiting phenomenon as more and more people picked up on the idea. There were creative variants on it; some people stuck `sig virus antibody' texts in their sigs, and there was at least one instance of a sig virus eater.

:signal-to-noise ratio: [from analog electronics] n. Used by hackers in a generalization of its technical meaning. `Signal' refers to useful information conveyed by some communications medium, and `noise' to anything else on that medium. Hence a low ratio implies that it is not worth paying attention to the medium in question. Figures for such metaphorical ratios are never given. The term is most often applied to {USENET} newsgroups during {flame war}s. Compare {bandwidth}. See also {coefficient of X}, {lost in the noise}.

:silicon: n. Hardware, esp. ICs or microprocessor-based computer systems (compare {iron}). Contrasted with software. See also {sandbender}.

:silicon foundry: n. A company that {fab}s chips to the designs of others. As of the late 1980s, the combination of silicon foundries and good computer-aided design software made it much easier for hardware-designing startup companies to come into being. The downside of using a silicon foundry is that the distance from the actual chip-fabrication processes reduces designers' control of detail. This is somewhat analogous to the use of {HLL}s versus coding in assembler.

:silly walk: [from Monty Python's Flying Circus] vi. 1. A ridiculous procedure required to accomplish a task. Like {grovel}, but more {random} and humorous. "I had to silly-walk through half the /usr directories to find the maps file." 2. Syn. {fandango on core}.

:silo: n. The FIFO input-character buffer in an RS-232 line card. So called from DEC terminology used on DH and DZ line cards for the VAX and PDP-11, presumably because it was a storage space for fungible stuff that you put in the top and took out the bottom.

:Silver Book: n. Jensen and Wirth's infamous `Pascal User Manual and Report', so called because of the silver cover of the widely distributed Springer-Verlag second edition of 1978 (ISBN 0-387-90144-2). See {{book titles}}, {Pascal}.

:since time T equals minus infinity: adj. A long time ago; for as long as anyone can remember; at the time that some particular frob was first designed. Usually the word `time' is omitted. See also {time T}.