Chapter 44

:trap door: /n./ (alt. `trapdoor') 1. Syn. {back door} -- a {Bad Thing}. 2. [techspeak] A `trap-door function' is one which is easy to compute but very difficult to compute the inverse of. Such functions are {Good Thing}s with important applications in cryptography, specifically in the construction of public-key cryptosystems.

:trash: /vt./ To destroy the contents of (said of a data structure). The most common of the family of near-synonyms including {mung}, {mangle}, and {scribble}.

:trawl: /v./ To sift through large volumes of data (e.g., Usenet postings, FTP archives, or the Jargon File) looking for something of interest.

:tree-killer: /n./ [Sun] 1. A printer. 2. A person who wastes paper. This epithet should be interpreted in a broad sense; `wasting paper' includes the production of {spiffy} but {content-free} documents. Thus, most {suit}s are tree-killers. The negative loading of this term may reflect the epithet `tree-killer' applied by Treebeard the Ent to the Orcs in J.R.R. Tolkien's "Lord of the Rings" (see also {elvish}, {elder days}).

:treeware: /tree'weir/ /n./ Printouts, books, and other information media made from pulped dead trees. Compare {tree-killer}, see {documentation}.

:trit: /trit/ /n./ [by analogy with `bit'] One base-3 digit; the amount of information conveyed by a selection among one of three equally likely outcomes (see also {bit}). Trits arise, for example, in the context of a {flag} that should actually be able to assume *three* values -- such as yes, no, or unknown. Trits are sometimes jokingly called `3-state bits'. A trit may be semi-seriously referred to as `a bit and a half', although it is linearly equivalent to 1.5849625 bits (that is, log2(3) bits).

:trivial: /adj./ 1. Too simple to bother detailing. 2. Not worth the speaker's time. 3. Complex, but solvable by methods so well known that anyone not utterly {cretinous} would have thought of them already. 4. Any problem one has already solved (some claim that hackish `trivial' usually evaluates to `I've seen it before'). Hackers' notions of triviality may be quite at variance with those of non-hackers. See {nontrivial}, {uninteresting}.

The physicist Richard Feynman, who had the hacker nature to an amazing degree (see his essay "Los Alamos From Below" in "Surely You're Joking, Mr. Feynman!"), defined `trivial theorem' as "one that has already been proved".

:troff:: /T'rof/ or /trof/ /n./ [Unix] The gray eminence of Unix text processing; a formatting and phototypesetting program, written originally in PDP-11 assembler and then in barely-structured early C by the late Joseph Ossanna, modeled after the earlier ROFF which was in turn modeled after Multics' RUNOFF by Jerome Saltzer (*that* name came from the expression "to run off a copy"). A companion program, {nroff}, formats output for terminals and line printers.

In 1979, Brian Kernighan modified troff so that it could drive phototypesetters other than the Graphic Systems CAT. His paper describing that work ("A Typesetter-independent troff," AT&T CSTR #97) explains troff's durability. After discussing the program's "obvious deficiencies -- a rebarbative input syntax, mysterious and undocumented properties in some areas, and a voracious appetite for computer resources" and noting the ugliness and extreme hairiness of the code and internals, Kernighan concludes:

None of these remarks should be taken as denigrating Ossanna's accomplishment with TROFF. It has proven a remarkably robust tool, taking unbelievable abuse from a variety of preprocessors and being forced into uses that were never conceived of in the original design, all with considerable grace under fire.

The success of {{TeX}} and desktop publishing systems have reduced `troff''s relative importance, but this tribute perfectly captures the strengths that secured `troff' a place in hacker folklore; indeed, it could be taken more generally as an indication of those qualities of good programs that, in the long run, hackers most admire.

:troglodyte: /n./ [Commodore] 1. A hacker who never leaves his cubicle. The term `Gnoll' (from Dungeons & Dragons) is also reported. 2. A curmudgeon attached to an obsolescent computing environment. The combination `ITS troglodyte' was flung around some during the Usenet and email wringle-wrangle attending the 2.x.x revision of the Jargon File; at least one of the people it was intended to describe adopted it with pride.

:troglodyte mode: /n./ [Rice University] Programming with the lights turned off, sunglasses on, and the terminal inverted (black on white) because you've been up for so many days straight that your eyes hurt (see {raster burn}). Loud music blaring from a stereo stacked in the corner is optional but recommended. See {larval stage}, {hack mode}.

:Trojan horse: /n./ [coined by MIT-hacker-turned-NSA-spook Dan Edwards] A malicious, security-breaking program that is disguised as something benign, such as a directory lister, archiver, game, or (in one notorious 1990 case on the Mac) a program to find and destroy viruses! See {back door}, {virus}, {worm}, {phage}, {mockingbird}.

:troll: /v.,n./ [From the Usenet group alt.folklore.urban] To utter a posting on {Usenet} designed to attract predictable responses or {flame}s. Derives from the phrase "trolling for {newbie}s" which in turn comes from mainstream "trolling", a style of fishing in which one trails bait through a likely spot hoping for a bite. The well-constructed troll is a post that induces lots of newbies and flamers to make themselves look even more clueless than they already do, while subtly conveying to the more savvy and experienced that it is in fact a deliberate troll. If you don't fall for the joke, you get to be in on it.

Some people claim that the troll is properly a narrower category than {flame bait}, that a troll is categorized by containing some assertion that is wrong but not overtly controversial.

:tron: /v./ [NRL, CMU; prob. fr. the movie "Tron"] To become inaccessible except via email or `talk(1)', especially when one is normally available via telephone or in person. Frequently used in the past tense, as in: "Ran seems to have tronned on us this week" or "Gee, Ran, glad you were able to un-tron yourself". One may also speak of `tron mode'; compare {spod}.

:true-hacker: /n./ [analogy with `trufan' from SF fandom] One who exemplifies the primary values of hacker culture, esp. competence and helpfulness to other hackers. A high compliment. "He spent 6 hours helping me bring up UUCP and netnews on my FOOBAR 4000 last week -- manifestly the act of a true-hacker." Compare {demigod}, oppose {munchkin}.

:tty: /T-T-Y/, /tit'ee/ /n./ The latter pronunciation was primarily ITS, but some Unix people say it this way as well; this pronunciation is *not* considered to have sexual undertones. 1. A terminal of the teletype variety, characterized by a noisy mechanical printer, a very limited character set, and poor print quality. Usage: antiquated (like the TTYs themselves). See also {bit-paired keyboard}. 2. [especially Unix] Any terminal at all; sometimes used to refer to the particular terminal controlling a given job. 3. [Unix] Any serial port, whether or not the device connected to it is a terminal; so called because under Unix such devices have names of the form tty*. Ambiguity between senses 2 and 3 is common but seldom bothersome.

:tube: 1. /n./ A CRT terminal. Never used in the mainstream sense of TV; real hackers don't watch TV, except for Loony Toons, Rocky & Bullwinkle, Trek Classic, the Simpsons, and the occasional cheesy old swashbuckler movie. 2. [IBM] To send a copy of something to someone else's terminal. "Tube me that note?"

:tube time: /n./ Time spent at a terminal or console. More inclusive than hacking time; commonly used in discussions of what parts of one's environment one uses most heavily. "I find I'm spending too much of my tube time reading mail since I started this revision."

:tunafish: /n./ In hackish lore, refers to the mutated punchline of an age-old joke to be found at the bottom of the manual pages of `tunefs(8)' in the original {BSD} 4.2 distribution. The joke was removed in later releases once commercial sites started using 4.2. Tunefs relates to the `tuning' of file-system parameters for optimum performance, and at the bottom of a few pages of wizardly inscriptions was a `BUGS' section consisting of the line "You can tune a file system, but you can't tunafish". Variants of this can be seen in other BSD versions, though it has been excised from some versions by humorless management {droid}s. The [nt]roff source for SunOS 4.1.1 contains a comment apparently designed to prevent this: "Take this out and a Unix Demon will dog your steps from now until the `time_t''s wrap around."

[It has since been pointed out that indeed you can tunafish. Usually at a canning factory... --ESR]

:tune: /vt./ [from automotive or musical usage] To optimize a program or system for a particular environment, esp. by adjusting numerical parameters designed as {hook}s for tuning, e.g., by changing `#define' lines in C. One may `tune for time' (fastest execution), `tune for space' (least memory use), or `tune for configuration' (most efficient use of hardware). See {bum}, {hot spot}, {hand-hacking}.

:turbo nerd: /n./ See {computer geek}.

:Turing tar-pit: /n./ 1. A place where anything is possible but nothing of interest is practical. Alan Turing helped lay the foundations of computer science by showing that all machines and languages capable of expressing a certain very primitive set of operations are logically equivalent in the kinds of computations they can carry out, and in principle have capabilities that differ only in speed from those of the most powerful and elegantly designed computers. However, no machine or language exactly matching Turing's primitive set has ever been built (other than possibly as a classroom exercise), because it would be horribly slow and far too painful to use. A `Turing tar-pit' is any computer language or other tool that shares this property. That is, it's theoretically universal -- but in practice, the harder you struggle to get any real work done, the deeper its inadequacies suck you in. Compare {bondage-and-discipline language}. 2. The perennial {holy wars} over whether language A or B is the "most powerful".

:turist: /too'rist/ /n./ Var. sp. of {tourist}, q.v. Also in adjectival form, `turistic'. Poss. influenced by {luser} and `Turing'.

:tweak: /vt./ 1. To change slightly, usually in reference to a value. Also used synonymously with {twiddle}. If a program is almost correct, rather than figure out the precise problem you might just keep tweaking it until it works. See {frobnicate} and {fudge factor}; also see {shotgun debugging}. 2. To {tune} or {bum} a program; preferred usage in the U.K.

:tweeter: /n./ [University of Waterloo] Syn. {perf}, {chad} (sense 1). This term (like {woofer}) has been in use at Waterloo since 1972 but is elsewhere unknown. In audio jargon, the word refers to the treble speaker(s) on a hi-fi.

:TWENEX:: /twe'neks/ /n./ The TOPS-20 operating system by DEC -- the second proprietary OS for the PDP-10 -- preferred by most PDP-10 hackers over TOPS-10 (that is, by those who were not {{ITS}} or {{WAITS}} partisans). TOPS-20 began in 1969 as Bolt, Beranek & Newman's TENEX operating system using special paging hardware. By the early 1970s, almost all of the systems on the ARPANET ran TENEX. DEC purchased the rights to TENEX from BBN and began work to make it their own. The first in-house code name for the operating system was VIROS (VIRtual memory Operating System); when customers started asking questions, the name was changed to SNARK so DEC could truthfully deny that there was any project called VIROS. When the name SNARK became known, the name was briefly reversed to become KRANS; this was quickly abandoned when someone objected that `krans' meant `funeral wreath' in Swedish (though some Swedish speakers have since said it means simply `wreath'; this part of the story may be apocryphal). Ultimately DEC picked TOPS-20 as the name of the operating system, and it was as TOPS-20 that it was marketed. The hacker community, mindful of its origins, quickly dubbed it TWENEX (a contraction of `twenty TENEX'), even though by this point very little of the original TENEX code remained (analogously to the differences between AT&T V6 Unix and BSD). DEC people cringed when they heard "TWENEX", but the term caught on nevertheless (the written abbreviation `20x' was also used). TWENEX was successful and very popular; in fact, there was a period in the early 1980s when it commanded as fervent a culture of partisans as Unix or ITS -- but DEC's decision to scrap all the internal rivals to the VAX architecture and its relatively stodgy VMS OS killed the DEC-20 and put a sad end to TWENEX's brief day in the sun. DEC attempted to convince TOPS-20 users to convert to {VMS}, but instead, by the late 1980s, most of the TOPS-20 hackers had migrated to Unix.

:twiddle: /n./ 1. Tilde (ASCII 1111110, `~'). Also called `squiggle', `sqiggle' (sic -- pronounced /skig'l/), and `twaddle', but twiddle is the most common term. 2. A small and insignificant change to a program. Usually fixes one bug and generates several new ones (see also {shotgun debugging}). 3. /vt./ To change something in a small way. Bits, for example, are often twiddled. Twiddling a switch or knob implies much less sense of purpose than toggling or tweaking it; see {frobnicate}. To speak of twiddling a bit connotes aimlessness, and at best doesn't specify what you're doing to the bit; `toggling a bit' has a more specific meaning (see {bit twiddling}, {toggle}).

:twilight zone: /n./ [IRC] Notionally, the area of cyberspace where {IRC} operators live. An {op} is said to have a "connection to the twilight zone".

:twink: /twink/ /n./ [UCSC] Equivalent to {read-only user}. Also reported on the Usenet group soc.motss; may derive from gay slang for a cute young thing with nothing upstairs (compare mainstream `chick').

:twirling baton: /n./ [PLATO] The overstrike sequence -/|\-/|\- which produces an animated twirling baton. If you output it with a single backspace between characters, the baton spins in place. If you output the sequence BS SP between characters, the baton spins from left to right. If you output BS SP BS BS between characters, the baton spins from right to left.

The twirling baton was a popular component of animated signature files on the pioneering PLATO educational timesharing system. The `archie' Internet service is perhaps the best-known baton program today; it uses the twirling baton as an idler indicating that the program is working on a query.

:two pi: /quant./ The number of years it takes to finish one's thesis. Occurs in stories in the following form: "He started on his thesis; 2 pi years later..."

:two-to-the-N: /quant./ An amount much larger than {N} but smaller than {infinity}. "I have 2-to-the-N things to do before I can go out for lunch" means you probably won't show up.

:twonkie: /twon'kee/ /n./ The software equivalent of a Twinkie (a variety of sugar-loaded junk food, or (in gay slang with a small t) the male equivalent of `chick'); a useless `feature' added to look sexy and placate a {marketroid} (compare {Saturday-night special}). The term may also be related to "The Twonky", title menace of a classic SF short story by Lewis Padgett (Henry Kuttner and C. L. Moore), first published in the September 1942 "Astounding Science Fiction" and subsequently much anthologized.

= U = =====

:u-: /pref./ Written shorthand for {micro-}; techspeak when applied to metric units, jargon when used otherwise. Derived from the Greek letter "mu", the first letter of "micro" (and which letter looks a lot like the English letter "u").

:UBD: /U-B-D/ /n./ [abbreviation for `User Brain Damage'] An abbreviation used to close out trouble reports obviously due to utter cluelessness on the user's part. Compare {pilot error}; oppose {PBD}; see also {brain-damaged}.

:UN*X: /n./ Used to refer to the Unix operating system (a trademark of AT&T) in writing, but avoiding the need for the ugly {(TM)} typography. Also used to refer to any or all varieties of Unixoid operating systems. Ironically, lawyers now say that the requirement for the TM-postfix has no legal force, but the asterisk usage is entrenched anyhow. It has been suggested that there may be a psychological connection to practice in certain religions (especially Judaism) in which the name of the deity is never written out in full, e.g., `YHWH' or `G--d' is used. See also {glob}.

:undefined external reference: /excl./ [Unix] A message from Unix's linker. Used in speech to flag loose ends or dangling references in an argument or discussion.

:under the hood: /adj./ [hot-rodder talk] 1. Used to introduce the underlying implementation of a product (hardware, software, or idea). Implies that the implementation is not intuitively obvious from the appearance, but the speaker is about to enable the listener to {grok} it. "Let's now look under the hood to see how ...." 2. Can also imply that the implementation is much simpler than the appearance would indicate: "Under the hood, we are just fork/execing the shell." 3. Inside a chassis, as in "Under the hood, this baby has a 40MHz 68030!"

:undocumented feature: /n./ See {feature}.

:uninteresting: /adj./ 1. Said of a problem that, although {nontrivial}, can be solved simply by throwing sufficient resources at it. 2. Also said of problems for which a solution would neither advance the state of the art nor be fun to design and code.

Hackers regard uninteresting problems as intolerable wastes of time, to be solved (if at all) by lesser mortals. *Real* hackers (see {toolsmith}) generalize uninteresting problems enough to make them interesting and solve them -- thus solving the original problem as a special case (and, it must be admitted, occasionally turning a molehill into a mountain, or a mountain into a tectonic plate). See {WOMBAT}, {SMOP}; compare {toy problem}, oppose {interesting}.

:Unix:: /yoo'niks/ /n./ [In the authors' words, "A weak pun on Multics"; very early on it was `UNICS'] (also `UNIX') An interactive time-sharing system invented in 1969 by Ken Thompson after Bell Labs left the Multics project, originally so he could play games on his scavenged PDP-7. Dennis Ritchie, the inventor of C, is considered a co-author of the system. The turning point in Unix's history came when it was reimplemented almost entirely in C during 1972--1974, making it the first source-portable OS. Unix subsequently underwent mutations and expansions at the hands of many different people, resulting in a uniquely flexible and developer-friendly environment. By 1991, Unix had become the most widely used multiuser general-purpose operating system in the world. Many people consider this the most important victory yet of hackerdom over industry opposition (but see {Unix weenie} and {Unix conspiracy} for an opposing point of view). See {Version 7}, {BSD}, {USG Unix}, {Linux}.

Some people are confused over whether this word is appropriately `UNIX' or `Unix'; both forms are common, and used interchangeably. Dennis Ritchie says that the `UNIX' spelling originally happened in CACM's 1974 paper "The UNIX Time-Sharing System" because "we had a new typesetter and {troff} had just been invented and we were intoxicated by being able to produce small caps." Later, dmr tried to get the spelling changed to `Unix' in a couple of Bell Labs papers, on the grounds that the word is not acronymic. He failed, and eventually (his words) "wimped out" on the issue. So, while the trademark today is `UNIX', both capitalizations are grounded in ancient usage; the Jargon File uses `Unix' in deference to dmr's wishes.

:Unix brain damage: /n./ Something that has to be done to break a network program (typically a mailer) on a non-Unix system so that it will interoperate with Unix systems. The hack may qualify as `Unix brain damage' if the program conforms to published standards and the Unix program in question does not. Unix brain damage happens because it is much easier for other (minority) systems to change their ways to match non-conforming behavior than it is to change all the hundreds of thousands of Unix systems out there.

An example of Unix brain damage is a {kluge} in a mail server to recognize bare line feed (the Unix newline) as an equivalent form to the Internet standard newline, which is a carriage return followed by a line feed. Such things can make even a hardened {jock} weep.

:Unix conspiracy: /n./ [ITS] According to a conspiracy theory long popular among {{ITS}} and {{TOPS-20}} fans, Unix's growth is the result of a plot, hatched during the 1970s at Bell Labs, whose intent was to hobble AT&T's competitors by making them dependent upon a system whose future evolution was to be under AT&T's control. This would be accomplished by disseminating an operating system that is apparently inexpensive and easily portable, but also relatively unreliable and insecure (so as to require continuing upgrades from AT&T). This theory was lent a substantial impetus in 1984 by the paper referenced in the {back door} entry.

In this view, Unix was designed to be one of the first computer viruses (see {virus}) -- but a virus spread to computers indirectly by people and market forces, rather than directly through disks and networks. Adherents of this `Unix virus' theory like to cite the fact that the well-known quotation "Unix is snake oil" was uttered by DEC president Kenneth Olsen shortly before DEC began actively promoting its own family of Unix workstations. (Olsen now claims to have been misquoted.)

[If there was ever such a conspiracy, it got thoroughly out of the plotters' control after 1990. AT&T sold its UNIX operation to Novell around the same time {Linux} and other free-UNIX distributions were beginning to make noise. --ESR]

:Unix weenie: /n./ [ITS] 1. A derogatory play on `Unix wizard', common among hackers who use Unix by necessity but would prefer alternatives. The implication is that although the person in question may consider mastery of Unix arcana to be a wizardly skill, the only real skill involved is the ability to tolerate (and the bad taste to wallow in) the incoherence and needless complexity that is alleged to infest many Unix programs. "This shell script tries to parse its arguments in 69 bletcherous ways. It must have been written by a real Unix weenie." 2. A derogatory term for anyone who engages in uncritical praise of Unix. Often appearing in the context "stupid Unix weenie". See {Weenix}, {Unix conspiracy}. See also {weenie}.