The Jargon File, Version 2.9.10, 01 Jul 1992. Various

is also a usage "ACK?" (from sense 1) meaning "Are you there?", often used in email when earlier mail has produced no reply, or during a lull in {talk mode} to see if the person has gone away (the standard humorous response is of course {NAK} (sense 2), i.e., "I'm not here").

      :ad-hockery: /ad-hok'*r-ee/ [Purdue] n. 1. Gratuitous assumptions made inside certain programs, esp. expert systems, which lead to the appearance of semi-intelligent behavior but are in fact entirely arbitrary. For example, fuzzy-matching input tokens that might be typing errors against a symbol table can make it look as though a program knows how to spell. 2. Special-case code to cope with some awkward input that would otherwise cause a program to {choke}, presuming normal inputs are dealt with in some cleaner and more regular way. Also called `ad-hackery', `ad-hocity' (/ad-hos'*-tee/), `ad-crockery'. See also {ELIZA effect}.

      :Ada:: n. A {{Pascal}}-descended language that has been made mandatory for Department of Defense software projects by the Pentagon. Hackers are nearly unanimous in observing that, technically, it is precisely what one might expect given that kind of endorsement by fiat; designed by committee, crockish, difficult to use, and overall a disastrous, multi-billion-dollar boondoggle (one common description is "The PL/I of the 1980s"). Hackers find Ada's exception-handling and inter-process communication features particularly hilarious. Ada Lovelace (the daughter of Lord Byron who became the world's first programmer while cooperating with Charles Babbage on the design of his mechanical computing engines in the mid-1800s) would almost certainly blanch at the use to which her name has latterly been put; the kindest thing that has been said about it is that there is probably a good small language screaming to get out from inside its vast, {elephantine} bulk.

      :adger: /aj'r/ [UCLA] vt. To make a bonehead move with consequences that could have been foreseen with a slight amount of mental effort. E.g., "He started removing files and promptly adgered the whole project". Compare {dumbass attack}.

      :admin: /ad-min'/ n. Short for `administrator'; very commonly used in speech or on-line to refer to the systems person in charge on a computer. Common constructions on this include `sysadmin' and `site admin' (emphasizing the administrator's role as a site contact for email and news) or `newsadmin' (focusing specifically on news). Compare {postmaster}, {sysop}, {system mangler}.

      :ADVENT: /ad'vent/ n. The prototypical computer adventure game, first implemented on the {PDP-10} by Will Crowther as an attempt at computer-refereed fantasy gaming, and expanded into a puzzle-oriented game by Don Woods. Now better known as Adventure, but the {{TOPS-10}} operating system permitted only 6-letter filenames. See also {vadding}.

      This game defined the terse, dryly humorous style now expected in text adventure games, and popularized several tag lines that have become fixtures of hacker-speak: "A huge green fierce snake bars the way!" "I see no X here" (for some noun X). "You are in a maze of twisty little passages, all alike." "You are in a little maze of twisty passages, all different." The `magic words' {xyzzy} and {plugh} also derive from this game.

      Crowther, by the way, participated in the exploration of the

       Mammoth & Flint Ridge cave system; it actually *has* a

       `Colossal Cave' and a `Bedquilt' as in the game, and the `Y2' that

       also turns up is cavers' jargon for a map reference to a secondary

       entrance.

      :AFJ: n. Written-only abbreviation for "April Fool's Joke".

       Elaborate April Fool's hoaxes are a hallowed tradition on USENET

       and Internet; see {kremvax} for an example. In fact, April

       Fool's Day is the *only* seasonal holiday marked by customary

       observances on the hacker networks.

      :AI-complete: /A-I k*m-pleet'/ [MIT, Stanford: by analogy with `NP-complete' (see {NP-})] adj. Used to describe problems or subproblems in AI, to indicate that the solution presupposes a solution to the `strong AI problem' (that is, the synthesis of a human-level intelligence). A problem that is AI-complete is, in other words, just too hard.

      Examples of AI-complete problems are `The Vision Problem' (building a system that can see as well as a human) and `The Natural Language Problem' (building a system that can understand and speak a natural language as well as a human). These may appear to be modular, but all attempts so far (1991) to solve them have foundered on the amount of context information and `intelligence' they seem to require. See also {gedanken}.

      :AI koans: /A-I koh'anz/ pl.n. A series of pastiches of Zen teaching riddles created by Danny Hillis at the MIT AI Lab around various major figures of the Lab's culture (several are included under "{A Selection of AI Koans}" in {appendix A}). See also {ha ha only serious}, {mu}, and {{Humor, Hacker}}.

      :AIDS: /aydz/ n. Short for A* Infected Disk Syndrome (`A*' is a {glob} pattern that matches, but is not limited to, Apple), this condition is quite often the result of practicing unsafe {SEX}. See {virus}, {worm}, {Trojan horse}, {virgin}.

      :AIDX: n. /aydkz/ n. Derogatory term for IBM's perverted version of UNIX, AIX, especially for the AIX 3.? used in the IBM RS/6000 series. A victim of the dreaded "hybridism" disease, this attempt to combine the two main currents of the UNIX stream ({BSD} and {USG UNIX}) became a {monstrosity} to haunt system administrators' dreams. For example, if new accounts are created while many users are logged on, the load average jumps quickly over 20 due to silly implementation of the user databases. For a quite similar disease, compare {HP-SUX}. Also, compare {terminak}, {Macintrash} {Nominal Semidestructor}, {Open DeathTrap}, {ScumOS}, {sun-stools}.

      :airplane rule: n. "Complexity increases the possibility of failure; a twin-engine airplane has twice as many engine problems as a single-engine airplane." By analogy, in both software and electronics, the rule that simplicity increases robustness (see also {KISS Principle}). It is correspondingly argued that the right way to build reliable systems is to put all your eggs in one basket, after making sure that you've built a really *good* basket.

      :aliasing bug: n. A class of subtle programming errors that can arise in code that does dynamic allocation, esp. via `malloc(3)' or equivalent. If more than one pointer addresses (`aliases for') a given hunk of storage, it may happen that the storage is freed or reallocated (and thus moved) through one alias and then referenced through another, which may lead to subtle (and possibly intermittent) lossage depending on the state and the allocation history of the malloc {arena}. Avoidable by use of allocation strategies that never alias allocated core. Also avoidable by use of higher-level languages, such as {LISP}, which employ a garbage collector (see {GC}). Also called a {stale pointer bug}. See also {precedence lossage}, {smash the stack}, {fandango on core}, {memory leak}, {memory smash}, {overrun screw}, {spam}.

      Historical note: Though this term is nowadays associated with

       C programming, it was already in use in a very similar sense in the

       Algol-60 and FORTRAN communities in the 1960s.

      :all-elbows: adj. Of a TSR (terminate-and-stay-resident) IBM PC program, such as the N pop-up calendar and calculator utilities that circulate on {BBS} systems: unsociable. Used to describe a program that rudely steals the resources that it needs without considering that other TSRs may also be resident. One particularly common form of rudeness is lock-up due to programs fighting over the keyboard interrupt. See {rude}, also {mess-dos}.

      :alpha particles: n. See {bit rot}.

      :alt: /awlt/ 1. n. The alt shift key on an IBM PC or {clone}. 2. n. The `clover' or `Command' key on a Macintosh; use of this term usually reveals that the speaker hacked PCs before coming to the Mac (see also {feature key}). Some Mac hackers, confusingly, reserve `alt' for the Option key. 3. n.obs. [PDP-10; often capitalized to ALT] Alternate name for the ASCII ESC character (ASCII 0011011), after the keycap labeling on some older terminals. Also `altmode' (/awlt'mohd/). This character was almost never pronounced `escape' on an ITS system, in {TECO}, or under TOPS-10 —- always alt, as in "Type alt alt to end a TECO command" or "alt-U onto the system" (for "log onto the [ITS] system"). This was probably because alt is more convenient to say than `escape', especially when followed by another alt or a character (or another alt *and* a character, for that matter).

      :alt