The Jargon File, Version 4.0.0, 24 Jul 1996
Chapter 8
:canonical: /adj./ [historically, `according to religious law'] The usual or standard state or manner of something. This word has a somewhat more technical meaning in mathematics. Two formulas such as 9 + x and x + 9 are said to be equivalent because they mean the same thing, but the second one is in `canonical form' because it is written in the usual way, with the highest power of x first. Usually there are fixed rules you can use to decide whether something is in canonical form. The jargon meaning, a relaxation of the technical meaning, acquired its present loading in computer-science culture largely through its prominence in Alonzo Church's work in computation theory and mathematical logic (see {Knights of the Lambda Calculus}). Compare {vanilla}.
Non-technical academics do not use the adjective `canonical' in any of the senses defined above with any regularity; they do however use the nouns `canon' and `canonicity' (not **canonicalness or **canonicality). The `canon' of a given author is the complete body of authentic works by that author (this usage is familiar to Sherlock Holmes fans as well as to literary scholars). `*The* canon' is the body of works in a given field (e.g., works of literature, or of art, or of music) deemed worthwhile for students to study and for scholars to investigate.
The word `canon' has an interesting history. It derives ultimately from the Greek `kanon' (akin to the English `cane') referring to a reed. Reeds were used for measurement, and in Latin and later Greek the word `canon' meant a rule or a standard. The establishment of a canon of scriptures within Christianity was meant to define a standard or a rule for the religion. The above non-techspeak academic usages stem from this instance of a defined and accepted body of work. Alongside this usage was the promulgation of `canons' (`rules') for the government of the Catholic Church. The techspeak usages ("according to religious law") derive from this use of the Latin `canon'.
Hackers invest this term with a playfulness that makes an ironic contrast with its historical meaning. A true story: One Bob Sjoberg, new at the MIT AI Lab, expressed some annoyance at the incessant use of jargon. Over his loud objections, GLS and RMS made a point of using as much of it as possible in his presence, and eventually it began to sink in. Finally, in one conversation, he used the word `canonical' in jargon-like fashion without thinking. Steele: "Aha! We've finally got you talking jargon too!" Stallman: "What did he say?" Steele: "Bob just used `canonical' in the canonical way."
Of course, canonicality depends on context, but it is implicitly defined as the way *hackers* normally expect things to be. Thus, a hacker may claim with a straight face that `according to religious law' is *not* the canonical meaning of `canonical'.
:card walloper: /n./ An EDP programmer who grinds out batch programs that do stupid things like print people's paychecks. Compare {code grinder}. See also {{punched card}}, {eighty-column mind}.
:careware: /keir'weir/ /n./ A variety of {shareware} for which either the author suggests that some payment be made to a nominated charity or a levy directed to charity is included on top of the distribution charge. Syn. {charityware}; compare {crippleware}, sense 2.
:cargo cult programming: /n./ A style of (incompetent) programming dominated by ritual inclusion of code or program structures that serve no real purpose. A cargo cult programmer will usually explain the extra code as a way of working around some bug encountered in the past, but usually neither the bug nor the reason the code apparently avoided the bug was ever fully understood (compare {shotgun debugging}, {voodoo programming}).
The term `cargo cult' is a reference to aboriginal religions that grew up in the South Pacific after World War II. The practices of these cults center on building elaborate mockups of airplanes and military style landing strips in the hope of bringing the return of the god-like airplanes that brought such marvelous cargo during the war. Hackish usage probably derives from Richard Feynman's characterization of certain practices as "cargo cult science" in his book "Surely You're Joking, Mr. Feynman!" (W. W. Norton & Co, New York 1985, ISBN 0-393-01921-7).
:cascade: /n./ 1. A huge volume of spurious error-message output produced by a compiler with poor error recovery. Too frequently, one trivial syntax error (such as a missing `)' or `}') throws the parser out of synch so that much of the remaining program text is interpreted as garbaged or ill-formed. 2. A chain of Usenet followups, each adding some trivial variation or riposte to the text of the previous one, all of which is reproduced in the new message; an {include war} in which the object is to create a sort of communal graffito.
:case and paste: /n./ [from `cut and paste'] 1. The addition of a new {feature} to an existing system by selecting the code from an existing feature and pasting it in with minor changes. Common in telephony circles because most operations in a telephone switch are selected using `case' statements. Leads to {software bloat}.
In some circles of EMACS users this is called `programming by Meta-W', because Meta-W is the EMACS command for copying a block of text to a kill buffer in preparation to pasting it in elsewhere. The term is condescending, implying that the programmer is acting mindlessly rather than thinking carefully about what is required to integrate the code for two similar cases.
At DEC, this is sometimes called `clone-and-hack' coding.
:casters-up mode: /n./ [IBM, prob. fr. slang belly up] Yet another synonym for `broken' or `down'. Usually connotes a major failure. A system (hardware or software) which is `down' may be already being restarted before the failure is noticed, whereas one which is `casters up' is usually a good excuse to take the rest of the day off (as long as you're not responsible for fixing it).
:casting the runes: /n./ What a {guru} does when you ask him or her to run a particular program and type at it because it never works for anyone else; esp. used when nobody can ever see what the guru is doing different from what J. Random Luser does. Compare {incantation}, {runes}, {examining the entrails}; also see the AI koan about Tom Knight in "{AI Koans}" (Appendix A).
A correspondent from England tells us that one of ICL's most talented systems designers used to be called out occasionally to service machines which the {field circus} had given up on. Since he knew the design inside out, he could often find faults simply by listening to a quick outline of the symptoms. He used to play on this by going to some site where the field circus had just spent the last two weeks solid trying to find a fault, and spreading a diagram of the system out on a table top. He'd then shake some chicken bones and cast them over the diagram, peer at the bones intently for a minute, and then tell them that a certain module needed replacing. The system would start working again immediately upon the replacement.
:cat: [from `catenate' via {{Unix}} `cat(1)'] /vt./ 1. [techspeak] To spew an entire file to the screen or some other output sink without pause. 2. By extension, to dump large amounts of data at an unprepared target or with no intention of browsing it carefully. Usage: considered silly. Rare outside Unix sites. See also {dd}, {BLT}.
Among Unix fans, `cat(1)' is considered an excellent example of user-interface design, because it delivers the file contents without such verbosity as spacing or headers between the files, and because it does not require the files to consist of lines of text, but works with any sort of data.
Among Unix haters, `cat(1)' is considered the {canonical} example of *bad* user-interface design, because of its woefully unobvious name. It is far more often used to {blast} a file to standard output than to concatenate two files. The name `cat' for the former operation is just as unintuitive as, say, LISP's {cdr}.
Of such oppositions are {holy wars} made....
:catatonic: /adj./ Describes a condition of suspended animation in which something is so {wedged} or {hung} that it makes no response. If you are typing on a terminal and suddenly the computer doesn't even echo the letters back to the screen as you type, let alone do what you're asking it to do, then the computer is suffering from catatonia (possibly because it has crashed). "There I was in the middle of a winning game of {nethack} and it went catatonic on me! Aaargh!" Compare {buzz}.
:cd tilde: /C-D til-d*/ /vi./ To go home. From the Unix C-shell and Korn-shell command `cd ~', which takes one to one's `$HOME' (`cd' with no arguments happens to do the same thing). By extension, may be used with other arguments; thus, over an electronic chat link, `cd ~coffee' would mean "I'm going to the coffee machine."
:CDA: /C-D-A/ The "Communications Decency Act" of 1996, passed on {Black Thursday} as section 502 of a major telecommunications reform bill. The CDA made it a federal crime in the USA to send a communication which is "obscene, lewd, lascivious, filthy, or indecent, with intent to annoy, abuse, threaten, or harass another person." It also threatens with imprisonment anyone who "knowingly" makes accessible to minors any message that "describes, in terms patently offensive as measured by contemporary community standards, sexual or excretory activities or organs".
While the CDA was sold as a measure to protect minors from the putative evils of pornography, the repressive political aims of the bill were laid bare by the Hyde amendment, which intended to outlaw discussion of abortion on the Internet.
To say that this direct attack on First Amendment free-speech rights was not well received on the Internet would be putting it mildly. A firestorm of protest followed, including a February 29th mass demonstration by thousands of netters who turned their {home page}s black for 48 hours. Several civil-rights groups and computing/telecommunications companies sought an immediate injunction to block enforcement of the CDA pending a constitutional challenge. This injunction was granted on the likelihood that plaintiffs would prevail on the merits of the case. At time of writing (Spring 1996), the fate of the CDA, and its effect on the Internet, is still unknown. See also {Exon}.
To join the fight against the CDA (if it's still law) and other forms of Internet censorship, visit the Center for Democracy and Technology Home Page at http://www.cdt.org.
:cdr: /ku'dr/ or /kuh'dr/ /vt./ [from LISP] To skip past the first item from a list of things (generalized from the LISP operation on binary tree structures, which returns a list consisting of all but the first element of its argument). In the form `cdr down', to trace down a list of elements: "Shall we cdr down the agenda?" Usage: silly. See also {loop through}.
Historical note: The instruction format of the IBM 704 that hosted the original LISP implementation featured two 15-bit fields called the `address' and `decrement' parts. The term `cdr' was originally `Contents of Decrement part of Register'. Similarly, `car' stood for `Contents of Address part of Register'.
The cdr and car operations have since become bases for formation of compound metaphors in non-LISP contexts. GLS recalls, for example, a programming project in which strings were represented as linked lists; the get-character and skip-character operations were of course called CHAR and CHDR.
:chad: /chad/ /n./ 1. The perforated edge strips on printer paper, after they have been separated from the printed portion. Also called {selvage} and {perf}. 2. obs. The confetti-like paper bits punched out of cards or paper tape; this has also been called `chaff', `computer confetti', and `keypunch droppings'. This use may now be mainstream; it has been reported seen (1993) in directions for a card-based voting machine in California.
Historical note: One correspondent believes `chad' (sense 2) derives from the Chadless keypunch (named for its inventor), which cut little u-shaped tabs in the card to make a hole when the tab folded back, rather than punching out a circle/rectangle; it was clear that if the Chadless keypunch didn't make them, then the stuff that other keypunches made had to be `chad'. There is a legend that the word was originally acronymic, standing for "Card Hole Aggregate Debris", but this has all the earmarks of a bogus folk etymology.
:chad box: /n./ A metal box about the size of a lunchbox (or in some models a large wastebasket), for collecting the {chad} (sense 2) that accumulated in {Iron Age} card punches. You had to open the covers of the card punch periodically and empty the chad box. The {bit bucket} was notionally the equivalent device in the CPU enclosure, which was typically across the room in another great gray-and-blue box.
:chain: 1. /vi./ [orig. from BASIC's `CHAIN' statement] To hand off execution to a child or successor without going through the {OS} command interpreter that invoked it. The state of the parent program is lost and there is no returning to it. Though this facility used to be common on memory-limited micros and is still widely supported for backward compatibility, the jargon usage is semi-obsolescent; in particular, most Unix programmers will think of this as an {exec}. Oppose the more modern `subshell'. 2. /n./ A series of linked data areas within an operating system or application. `Chain rattling' is the process of repeatedly running through the linked data areas searching for one which is of interest to the executing program. The implication is that there is a very large number of links on the chain.
:channel: /n./ [IRC] The basic unit of discussion on {IRC}. Once one joins a channel, everything one types is read by others on that channel. Channels are named with strings that begin with a `#' sign and can have topic descriptions (which are generally irrelevant to the actual subject of discussion). Some notable channels are `#initgame', `#hottub', and `#report'. At times of international crisis, `#report' has hundreds of members, some of whom take turns listening to various news services and typing in summaries of the news, or in some cases, giving first-hand accounts of the action (e.g., Scud missile attacks in Tel Aviv during the Gulf War in 1991).
:channel hopping: /n./ [IRC, GEnie] To rapidly switch channels on {IRC}, or a GEnie chat board, just as a social butterfly might hop from one group to another at a party. This term may derive from the TV watcher's idiom, `channel surfing'.
:channel op: /chan'l op/ /n./ [IRC] Someone who is endowed with privileges on a particular {IRC} channel; commonly abbreviated `chanop' or `CHOP'. These privileges include the right to {kick} users, to change various status bits, and to make others into CHOPs.
:chanop: /chan'-op/ /n./ [IRC] See {channel op}.
:char: /keir/ or /char/; rarely, /kar/ /n./ Shorthand for `character'. Esp. used by C programmers, as `char' is C's typename for character data.
:charityware: /cha'rit-ee-weir`/ /n./ Syn. {careware}.
:chase pointers: 1. /vi./ To go through multiple levels of indirection, as in traversing a linked list or graph structure. Used esp. by programmers in C, where explicit pointers are a very common data type. This is techspeak, but it remains jargon when used of human networks. "I'm chasing pointers. Bob said you could tell me who to talk to about...." See {dangling pointer} and {snap}. 2. [Cambridge] `pointer chase' or `pointer hunt': The process of going through a {core dump} (sense 1), interactively or on a large piece of paper printed with hex {runes}, following dynamic data-structures. Used only in a debugging context.
:chawmp: /n./ [University of Florida] 16 or 18 bits (half of a machine word). This term was used by FORTH hackers during the late 1970s/early 1980s; it is said to have been archaic then, and may now be obsolete. It was coined in revolt against the promiscuous use of `word' for anything between 16 and 32 bits; `word' has an additional special meaning for FORTH hacks that made the overloading intolerable. For similar reasons, /gaw'bl/ (spelled `gawble' or possibly `gawbul') was in use as a term for 32 or 48 bits (presumably a full machine word, but our sources are unclear on this). These terms are more easily understood if one thinks of them as faithful phonetic spellings of `chomp' and `gobble' pronounced in a Florida or other Southern U.S. dialect. For general discussion of similar terms, see {nybble}.
:check: /n./ A hardware-detected error condition, most commonly used to refer to actual hardware failures rather than software-induced traps. E.g., a `parity check' is the result of a hardware-detected parity error. Recorded here because the word often humorously extended to non-technical problems. For example, the term `child check' has been used to refer to the problems caused by a small child who is curious to know what happens when s/he presses all the cute buttons on a computer's console (of course, this particular problem could have been prevented with {molly-guard}s).
:chemist: /n./ [Cambridge] Someone who wastes computer time on {number-crunching} when you'd far rather the machine were doing something more productive, such as working out anagrams of your name or printing Snoopy calendars or running {life} patterns. May or may not refer to someone who actually studies chemistry.
:Chernobyl chicken: /n./ See {laser chicken}.
:Chernobyl packet: /cher-noh'b*l pak'*t/ /n./ A network packet that induces a {broadcast storm} and/or {network meltdown}, in memory of the April 1986 nuclear accident at Chernobyl in Ukraine. The typical scenario involves an IP Ethernet datagram that passes through a gateway with both source and destination Ether and IP address set as the respective broadcast addresses for the subnetworks being gated between. Compare {Christmas tree packet}.
:chicken head: /n./ [Commodore] The Commodore Business Machines logo, which strongly resembles a poultry part. Rendered in ASCII as `C='. With the arguable exception of the Amiga (see {amoeba}), Commodore's machines are notoriously crocky little {bitty box}es (see also {PETSCII}). Thus, this usage may owe something to Philip K. Dick's novel "Do Androids Dream of Electric Sheep?" (the basis for the movie "Blade Runner"; the novel is now sold under that title), in which a `chickenhead' is a mutant with below-average intelligence.
:chiclet keyboard: /n./ A keyboard with a small, flat rectangular or lozenge-shaped rubber or plastic keys that look like pieces of chewing gum. (Chiclets is the brand name of a variety of chewing gum that does in fact resemble the keys of chiclet keyboards.) Used esp. to describe the original IBM PCjr keyboard. Vendors unanimously liked these because they were cheap, and a lot of early portable and laptop products got launched using them. Customers rejected the idea with almost equal unanimity, and chiclets are not often seen on anything larger than a digital watch any more.
:chine nual: /sheen'yu-*l/ /n. obs./ [MIT] The LISP Machine Manual, so called because the title was wrapped around the cover so only those letters showed on the front.
:Chinese Army technique: /n./ Syn. {Mongolian Hordes technique}.
:choad: /chohd/ /n./ Synonym for `penis' used in alt.tasteless and popularized by the denizens thereof. They say: "We think maybe it's from Middle English but we're all too damned lazy to check the OED." [I'm not. It isn't. --ESR] This term is alleged to have been inherited through 1960s underground comics, and to have been recently sighted in the Beavis and Butthead cartoons. Speakers of the Hindi, Bengali and Gujarati languages have confirmed that `choad' is in fact an Indian vernacular word equivalent to `fuck'; it is therefore likely to have entered English slang via the British Raj.
:choke: /v./ 1. To reject input, often ungracefully. "NULs make System V's `lpr(1)' choke." "I tried building an {EMACS} binary to use {X}, but `cpp(1)' choked on all those `#define's." See {barf}, {gag}, {vi}. 2. [MIT] More generally, to fail at any endeavor, but with some flair or bravado; the popular definition is "to snatch defeat from the jaws of victory."
:chomp: /vi./ To {lose}; specifically, to chew on something of which more was bitten off than one can. Probably related to gnashing of teeth. See {bagbiter}.
A hand gesture commonly accompanies this. To perform it, hold the four fingers together and place the thumb against their tips. Now open and close your hand rapidly to suggest a biting action (much like what Pac-Man does in the classic video game, though this pantomime seems to predate that). The gesture alone means `chomp chomp' (see "{Verb Doubling}" in the "{Jargon Construction}" section of the Prependices). The hand may be pointed at the object of complaint, and for real emphasis you can use both hands at once. Doing this to a person is equivalent to saying "You chomper!" If you point the gesture at yourself, it is a humble but humorous admission of some failure. You might do this if someone told you that a program you had written had failed in some surprising way and you felt dumb for not having anticipated it.
:chomper: /n./ Someone or something that is chomping; a loser. See {loser}, {bagbiter}, {chomp}.
:CHOP: /chop/ /n./ [IRC] See {channel op}.
:Christmas tree: /n./ A kind of RS-232 line tester or breakout box featuring rows of blinking red and green LEDs suggestive of Christmas lights.
:Christmas tree packet: /n./ A packet with every single option set for whatever protocol is in use. See {kamikaze packet}, {Chernobyl packet}. (The term doubtless derives from a fanciful image of each little option bit being represented by a different-colored light bulb, all turned on.)
:chrome: /n./ [from automotive slang via wargaming] Showy features added to attract users but contributing little or nothing to the power of a system. "The 3D icons in Motif are just chrome, but they certainly are *pretty* chrome!" Distinguished from {bells and whistles} by the fact that the latter are usually added to gratify developers' own desires for featurefulness. Often used as a term of contempt.
:chug: /vi./ To run slowly; to {grind} or {grovel}. "The disk is chugging like crazy."