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Jargon used in computing

= L =

lace card: n. obs. A {{punched card}} with all holes punched (also called a `whoopee card').
   Card readers jammed when they got to one of these, as the resulting card had too little
   structural strength to avoid buckling inside the mechanism.  Card punches could also jam
   trying to produce these things owing to power-supply problems.  When some practical joker
   fed a lace card through the reader, you needed to clear the jam with a `card knife' ---
   which you used on the joker first.

language lawyer: n. A person, usually an experienced or senior software engineer, who is
   intimately familiar with many or most of the numerous restrictions and features (both
   useful and esoteric) applicable to one or more computer programming languages. A language
   lawyer is distinguished by the ability to show you the five sentences scattered through a
   200-plus-page manual that together imply the answer to your question "if only you had
   thought to look there".  Compare {wizard}, {legal}, {legalese}.

languages of choice: n. {C} and {LISP}.  Nearly every hacker knows one of these, and most good
   ones are fluent in both.  Smalltalk and Prolog are also popular in small but influential
   There is also a rapidly dwindling category of older hackers with FORTRAN, or even assembler,
   as their language of choice. They often prefer to be known as {real programmer}s, and other
   hackers consider them a bit odd (see "The Story of Mel, a Real Programmer" in appendix A).
   Assembler is generally no longer considered interesting or appropriate for anything but
   {HLL} implementation, {glue}, and a few time-critical and hardware-specific uses in systems
   programs.  FORTRAN occupies a shrinking niche in scientific programming.
   Most hackers tend to frown on languages like {{Pascal}} and {{Ada}}, which don't give them
   the near-total freedom considered necessary for hacking (see {bondage-and-discipline
   language}), and to regard everything that's even remotely connected with {COBOL} or other
   traditional {card walloper} languages as a total and unmitigated {loss}.

larval stage: n. Describes a period of monomaniacal concentration on coding apparently passed
   through by all fledgling hackers. Common symptoms include the perpetration of more than one
   36-hour {hacking run} in a given week; neglect of all other activities including usual
   basics like food, sleep, and personal hygiene; and a chronic case of advanced bleary-eye.
   Can last from 6 months to 2 years, the apparent median being around 18 months.  A few so
   afflicted never resume a more `normal' life, but the ordeal seems to be necessary to
   produce really wizardly (as opposed to merely competent) programmers.  See also {wannabee}.
   A less protracted and intense version of larval stage (typically lasting about a month) may
   recur when one is learning a new {OS} or programming language.

lase: /layz/ vt. To print a given document via a laser printer. "OK, let's lase that sucker
   and see if all those graphics-macro calls did the right things."

laser chicken: n. Kung Pao Chicken, a standard Chinese dish containing chicken, peanuts, and
   hot red peppers in a spicy pepper-oil sauce.  Many hackers call it `laser chicken' for two
   reasons: It can {zap} you just like a laser, and the sauce has a red color reminiscent of
   some laser beams.
   In a variation on this theme, it is reported that some Australian hackers have redesignated
   the common dish `lemon chicken' as `Chernobyl Chicken'. The name is derived from the colour
   of the sauce, which is considered bright enough to glow in the dark (as, mythically, do
   some of the inhabitants of Chernobyl).

laundromat: n. Syn. {disk farm}; see {washing machine}.

LDB: /l*'d*b/ [from the PDP-10 instruction set] vt. To extract from the middle. "LDB me a
   slice of cake, please." This usage has been kept alive by Common LISP's function of the
   same name. Considered silly.  See also {DPB}.

leaf site: n. A machine that merely originates and reads USENET news or mail, and does not
   relay any third-party traffic. Often uttered in a critical tone; when the ratio of leaf
   sites to backbone, rib, and other relay sites gets too high, the network tends to develop
   bottlenecks.  Compare {backbone site}, {rib site}.

leak: n. With qualifier, one of a class of resource-management bugs that occur when resources
   are not freed properly after operations on them are finished, so they effectively disappear
   (leak out). This leads to eventual exhaustion as new allocation requests come in. {memory
   leak} and {fd leak} have their own entries; one might also refer, to, say, a `window handle
   leak' in a window system.

leaky heap: [Cambridge] n. An {arena} with a {memory leak}.

legal: adj. Loosely used to mean `in accordance with all the relevant rules', esp. in
   connection with some set of constraints defined by software. "The older =+ alternate for +=
   is no longer legal syntax in ANSI C."  "This parser processes each line of legal input the
   moment it sees the trailing linefeed."  Hackers often model their work as a sort of game
   played with the environment in which the objective is to maneuver through the thicket of
   `natural laws' to achieve a desired objective.  Their use of `legal' is flavored as much by
   this game-playing sense as by the more conventional one having to do with courts and
   lawyers. Compare {language lawyer}, {legalese}.

legalese: n. Dense, pedantic verbiage in a language description, product specification, or
   interface standard; text that seems designed to obfuscate and requires a {language lawyer}
   to {parse} it. Though hackers are not afraid of high information density and complexity in
   language (indeed, they rather enjoy both), they share a deep and abiding loathing for
   legalese; they associate it with deception, {suit}s, and situations in which hackers
   generally get the short end of the stick.

LER: /L-E-R/ [TMRC, from `Light-Emitting Diode] n. A light-emitting resistor (that is, one in
   the process of burning up).  Ohm's law was broken.  See {SED}.

LERP: /lerp/ vi.,n. Quasi-acronym for Linear Interpolation, used as a verb or noun for the
   operation.  E.g., Bresenham's algorithm lerps incrementally between the two endpoints of
   the line.

let the smoke out: v. To fry hardware (see {fried}). See {magic smoke} for the mythology
   behind this.

letterbomb: n. A piece of {email} containing {live data} intended to do nefarious things to
   the recipient's machine or terminal. It is possible, for example, to send letterbombs that
   will lock up some specific kinds of terminals when they are viewed, so thoroughly that the
   user must {cycle power} to unwedge them. Under UNIX, a letterbomb can also try to get part
   of its contents interpreted as a shell command to the mailer. The results of this could
   range from silly to tragic.  See also {Trojan horse}; compare {nastygram}.

lexer: /lek'sr/ n. Common hacker shorthand for `lexical analyzer', the input-tokenizing stage
   in the parser for a language (the part that breaks it into word-like pieces). "Some C
   lexers get confused by the old-style compound ops like `=-'."

lexiphage: /lek'si-fayj`/ n. A notorious word {chomper} on ITS.  See {bagbiter}.

life: n. 1. A cellular-automata game invented by John Horton Conway and first introduced
   publicly by Martin Gardner (`Scientific  American', October 1970).  Many hackers pass
   through a stage of fascination with it, and hackers at various places contributed heavily
   to the mathematical analysis of this game (most notably Bill Gosper at MIT, who even
   implemented life in {TECO}!; see {Gosperism}).  When a hacker mentions `life', he is much
   more likely to mean this game than the magazine, the breakfast cereal, or the human state
   of existence.  2. The opposite of {USENET}. As in {Get a life!}

light pipe: n. Fiber optic cable.  Oppose {copper}.

like kicking dead whales down the beach: adj. Describes a slow, difficult, and disgusting
   process.  First popularized by a famous quote about the difficulty of getting work done
   under one of IBM's mainframe OSes.  "Well, you *could* write a C compiler in COBOL, but it
   would be like kicking dead whales down the beach." See also {fear and loathing}

like nailing jelly to a tree: adj. Used to describe a task thought to be impossible, esp. one
   in which the difficulty arises from poor specification or inherent slipperiness in the
   problem domain. "Trying to display the `prettiest' arrangement of nodes and arcs that
   diagrams a given graph is like nailing jelly to a tree, because nobody's sure what
   `prettiest' means algorithmically."

line eater, the: [USENET] n. 1. A bug in some now-obsolete versions of the netnews software
   that used to eat up to BUFSIZ bytes of the article text.  The bug was triggered by having
   the text of the article start with a space or tab.  This bug was quickly personified as a
   mythical creature called the `line eater', and postings often included a dummy line of
   `line eater food'.  Ironically, line eater `food' not beginning with a space or tab wasn't
   actually eaten, since the bug was avoided; but if there *was* a space or tab before it,
   then the line eater would eat the food *and* the beginning of the text it was supposed to
   be protecting.  The practice of `sacrificing to the line eater' continued for some time
   after the bug had been {nailed to the wall}, and is still humourously referred to. The bug
   itself is still (in mid-1991) occasionally reported to be lurking in some mail-to-netnews
   gateways.  2. See {NSA line eater}.

line starve: [MIT] 1. vi. To feed paper through a printer the wrong way by one line (most
   printers can't do this).  On a display terminal, to move the cursor up to the previous line
   of the screen. "To print `X squared', you just output `X', line starve, `2', line feed."
   (The line starve causes the `2' to appear on the line above the `X', and the line feed gets
   back to the original line.) 2. n. A character (or character sequence) that causes a terminal
   to perform this action.  Unlike `line feed', `line starve' is *not* standard {{ASCII}}
   terminology. Even among hackers it is considered a bit silly. 3. [proposed] A sequence such
   as \c (used in System V echo, as well as nroff/troff) that suppresses a {newline} or other
   character(s) that would normally be emitted.

link farm: [UNIX] n. A directory tree that contains many links to files in a master directory
   tree of files.  Link farms save space when (for example) one is maintaining several nearly
   identical copies of the same source tree, e.g., when the only difference is
   architecture-dependent object files.  "Let's freeze the source and then rebuild the
   FROBOZZ-3 and FROBOZZ-4 link farms." Link farms may also be used to get around restrictions
   on the number of `-I' (include-file directory) arguments on older C preprocessors.

link-dead: [MUD] adj. Said of a {MUD} character who has frozen in place because of a dropped
   Internet connection.

lint: [from UNIX's `lint(1)', named perhaps for the bits of fluff it picks from programs] 1.
   vt. To examine a program closely for style, language usage, and portability problems, esp.
   if in C, esp. if via use of automated analysis tools, most esp. if the UNIX utility
   `lint(1)' is used. This term used to be restricted to use of `lint(1)' itself, but (judging
   by references on USENET) it has become a shorthand for {desk check} at some non-UNIX shops,
   even in languages other than C. Also as v.  {delint}.  2. n. Excess verbiage in a document,
   as in "this draft has too much lint".

lion food: [IBM] n. Middle management or HQ staff (by extension, administrative drones in
   general). From an old joke about two lions who, escaping from the zoo, split up to increase
   their chances but agreed to meet after 2 months.  When they finally meet, one is skinny and
   the other overweight.  The thin one says: "How did you manage?  I ate a human just once and
   they turned out a small army to chase me --- guns, nets, it was terrible. Since then I've
   been reduced to eating mice, insects, even grass." The fat one replies: "Well, *I* hid near
   an IBM office and ate a manager a day.  And nobody even noticed!"

Lions Book: n. `Source Code and Commentary on UNIX level 6', by John Lions. The two parts of
   this book contained (1) the entire source listing of the UNIX Version 6 kernel, and (2) a
   commentary on the source discussing the algorithms. These were circulated internally at the
   University of New South Wales beginning 1976--77, and were for years after the *only*
   detailed kernel documentation available to anyone outside Bell Labs. Because Western
   Electric wished to maintain trade secret status on the kernel, the Lions book was never
   formally published and was only supposed to be distributed to affiliates of source
   licensees. In spite of this, it soon spread by samizdat to a good many of the early UNIX

LISP: [from `LISt Processing language', but mythically from `Lots of Irritating Superfluous
   Parentheses'] n. The name of AI's mother tongue, a language based on the ideas of (a)
   variable-length lists and trees as fundamental data types, and (b) the interpretation of
   code as data and vice-versa. Invented by John McCarthy at MIT in the late 1950s, it is
   actually older than any other {HLL} still in use except FORTRAN. Accordingly, it has
   undergone considerable adaptive radiation over the years; modern variants are quite
   different in detail from the original LISP 1.5. The dominant HLL among hackers until the
   early 1980s, LISP now shares the throne with {C}.  See {languages of choice}.
   All LISP functions and programs are expressions that return values; this, together with the
   high memory utilization of LISPs, gave rise to Alan Perlis's famous quip (itself a take on
   an Oscar Wilde quote) that "LISP programmers know the value of everything and the cost of
   One significant application for LISP has been as a proof by example that most newer
   languages, such as {COBOL} and {Ada}, are full of unnecessary {crock}s. When the {Right
   Thing} has already been done once, there is no justification for {bogosity} in newer

literature, the: n. Computer-science journals and other publications, vaguely gestured at to
   answer a question that the speaker believes is {trivial}. Thus, one might answer an annoying
   question by saying "It's in the literature."  Oppose {Knuth}, which has no connotation of

little-endian: adj. Describes a computer architecture in which, within a given 16- or 32-bit
   word, bytes at lower addresses have lower significance (the word is stored `little-end-
   first'). The PDP-11 and VAX families of computers and Intel microprocessors and a lot of
   communications and networking hardware are little-endian. See {big-endian}, {middle-endian},
   {NUXI problem}.  The term is sometimes used to describe the ordering of units other than
   bytes; most often these are bits within a byte.

live data: n. 1. Data that is written to be interpreted and takes over program flow when
   triggered by some un-obvious operation, such as viewing it.  One use of such hacks is to
   break security.  For example, some smart terminals have commands that allow one to download
   strings to program keys; this can be used to write live data that, when listed to the
   terminal, infects it with a security-breaking {virus} that is triggered the next time a
   hapless user strikes that key.  For another, there are some well-known bugs in {vi} that
   allow certain texts to send arbitrary commands back to the machine when they are simply
   viewed. 2. In C code, data that includes pointers to function {hook}s (executable code).
   3. An object, such as a {trampoline}, that is constructed on the fly by a program and
   intended to be executed as code. 4. Actual real-world data, as opposed to `test data'. For
   example, "I think I have the record deletion module finished."  "Have you tried it out on
   live data?"  It usually carries the connotation that live data is more fragile and must not
   be corrupted, else bad things will happen.  So a possible alternate response to the above
   claim might be: "Well, make sure it works perfectly before we throw live data at it."  The
   implication here is that record deletion is something pretty significant, and a haywire
   record-deletion module running amok on live data would cause great harm and probably
   require restoring from backups.

Live Free Or Die!: imp. 1. The state motto of New Hampshire, which appears on that state's
   automobile license plates.  2. A slogan associated with UNIX in the romantic days when UNIX
   aficionados saw themselves as a tiny, beleaguered underground tilting against the windmills
   of industry.  The "free" referred specifically to freedom from the {fascist} design
   philosophies and crufty misfeatures common on commercial operating systems. Armando
   Stettner, one of the early UNIX developers, used to give out fake license plates bearing
   this motto under a large UNIX, all in New Hampshire colors of green and white. These are
   now valued collector's items.

livelock: /li:v'lok/ n. A situation in which some critical stage of a task is unable to finish
   because its clients perpetually create more work for it to do after they have been serviced
   but before it can clear its queue.  Differs from {deadlock} in that the process is not
   blocked or waiting for anything, but has a virtually infinite amount of work to do and can
   never catch up.

liveware: /li:v'weir/ n. 1. Synonym for {wetware}.  Less common. 2. [Cambridge] Vermin.
   "Waiter, there's some liveware in my salad..."

lobotomy: n. 1. What a hacker subjected to formal management training is said to have
   undergone. At IBM and elsewhere this term is used by both hackers and low-level management;
   the latter doubtless intend it as a joke.  2. The act of removing the processor from a
   microcomputer in order to replace or upgrade it. Some very cheap {clone} systems are sold
   in `lobotomized' form --- everything but the brain.

locked and loaded: [from military slang for an M-16 rifle with magazine inserted and prepared
   for firing] adj. Said of a removable disk volume properly prepared for use --- that is,
   locked into the drive and with the heads loaded.  Ironically, because their heads are
   `loaded' whenever the power is up, this description is never used of {{Winchester}} drives
   (which are named after a rifle).

locked up: adj. Syn. for {hung}, {wedged}.

logic bomb: n. Code surreptitiously inserted in an application or OS that causes it to perform
   some destructive or security-compromising activity whenever specified conditions are met.
   Compare {back door}.

logical: [from the technical term `logical device', wherein a physical device is referred to
   by an arbitrary `logical' name] adj.  Having the role of.  If a person (say, Les Earnest at
   SAIL) who had long held a certain post left and were replaced, the replacement would for a
   while be known as the `logical' Les Earnest.  (This does not imply any judgment on the
   replacement.)  Compare {virtual}.
   At Stanford, `logical' compass directions denote a coordinate system in which `logical
   north' is toward San Francisco, `logical west' is toward the ocean, etc., even though
   logical north varies between physical (true) north near San Francisco and physical west
   near San Jose. (The best rule of thumb here is that, by definition, El Camino Real always
   runs logical north-and-south.) In giving directions, one might say: "To get to Rincon
   Tarasco restaurant, get onto {El Camino Bignum} going logical north." Using the word
   `logical' helps to prevent the recipient from worrying about that the fact that the sun is
   setting almost directly in front of him. The concept is reinforced by North American
   highways which are almost, but not quite, consistently labeled with logical rather than
   physical directions. A similar situation exists at MIT.  Route 128 (famous for the
   electronics industry that has grown up along it) is a 3-quarters circle surrounding Boston
   at a radius of 10 miles, terminating near the coastline at each end.  It would be most
   precise to describe the two directions along this highway as `clockwise' and
   `counterclockwise', but the road signs all say "north" and "south", respectively. A hacker
   might describe these directions as `logical north' and `logical south', to indicate that
   they are conventional directions not corresponding to the usual denotation for those words.
   (If you went logical south along the entire length of route 128, you would start out going
   northwest, curve around to the south, and finish headed due east!)

loop through: vt. To process each element of a list of things. "Hold on, I've got to loop
   through my paper mail."  Derives from the computer-language notion of an iterative loop;
   compare `cdr down' (under {cdr}), which is less common among C and UNIX programmers. ITS
   hackers used to say `IRP over' after an obscure pseudo-op in the MIDAS PDP-10 assembler.

lord high fixer: [primarily British, from Gilbert & Sullivan's `lord high executioner'] n. The
   person in an organization who knows the most about some aspect of a system.  See {wizard}.

lose: [MIT] vi. 1. To fail. A program loses when it encounters an exceptional condition or
   fails to work in the expected manner. 2. To be exceptionally unesthetic or crocky. 3. Of
   people, to be obnoxious or unusually stupid (as opposed to ignorant). See also {deserves to
   lose}. 4. n. Refers to something that is {losing}, especially in the phrases "That's a
   lose!" and "What a lose!"

lose lose: interj. A reply to or comment on an undesirable situation. "I accidentally deleted
   all my files!"  "Lose, lose."

loser: n. An unexpectedly bad situation, program, programmer, or person. Someone who habitually
   loses. (Even winners can lose occasionally.)  Someone who knows not and knows not that he
   knows not. Emphatic forms are `real loser', `total loser', and `complete loser' (but not
   *`moby loser', which would be a contradiction in terms).  See {luser}.

losing: adj. Said of anything that is or causes a {lose} or {lossage}.

loss: n. Something (not a person) that loses; a situation in which something is losing.
   Emphatic forms include `moby loss', and `total loss', `complete loss'. Common interjections
   are "What a loss!"  and "What a moby loss!"  Note that `moby loss' is OK even though `moby
   loser' is not used; applied to an abstract noun, moby is simply a magnifier, whereas when
   applied to a person it implies substance and has positive connotations.  Compare {lossage}.

lossage: /los'*j/ n. The result of a bug or malfunction.  This is a mass or collective noun.
   "What a loss!" and "What lossage!"  are nearly synonymous.  The former is slightly more
   particular to the speaker's present circumstances; the latter implies a continuing {lose}
   of which the speaker is currently a victim.  Thus (for example) a temporary hardware
   failure is a loss, but bugs in an important tool (like a compiler) are serious lossage.

lost in the noise: adj. Syn. {lost in the underflow}.  This term is from signal processing,
   where signals of very small amplitude cannot be separated from low-intensity noise in the
   system.  Though popular among hackers, it is not confined to hackerdom; physicists,
   engineers, astronomers, and statisticians all use it.

lost in the underflow: adj. Too small to be worth considering; more specifically, small beyond
   the limits of accuracy or measurement.  This is a reference to `floating underflow', a
   condition that can occur when a floating-point arithmetic processor tries to handle
   quantities smaller than its limit of magnitude. It is also a pun on `undertow' (a kind of
   fast, cold current that sometimes runs just offshore and can be dangerous to swimmers).
   "Well, sure, photon pressure from the stadium lights alters the path of a thrown baseball,
   but that effect gets lost in the underflow."  See also {overflow bit}.

lots of MIPS but no I/O: adj. Used to describe a person who is technically brilliant but can't
   seem to communicate with human beings effectively.  Technically it describes a machine that
   has lots of processing power but is bottlenecked on input-output (in 1991, the IBM Rios,
   a.k.a. RS/6000, is a notorious recent example).

low-bandwidth: [from communication theory] adj. Used to indicate a talk that, although not
   {content-free}, was not terribly informative.  "That was a low-bandwidth talk, but what can
   you expect for an audience of {suit}s!"  Compare {zero-content}, {bandwidth}, {math-out}.

LPT: /L-P-T/ or /lip'it/ or /lip-it'/ [MIT, via DEC] n. Line printer, of course. Rare under
   UNIX, commoner in hackers with MS-DOS or CP/M background. The printer device is called
   `LPT:' on those systems that, like ITS, were strongly influenced by early DEC conventions.

lunatic fringe: [IBM] n. Customers who can be relied upon to accept release 1 versions of

lurker: n. One of the `silent majority' in a electronic forum; one who posts occasionally or
   not at all but is known to read the group's postings regularly. This term is not pejorative
   and indeed is casually used reflexively: "Oh, I'm just lurking."  Often used in `the
    lurkers', the hypothetical audience for the group's {flamage}-emitting regulars.

luser: /loo'zr/ n. A {user}; esp. one who is also a {loser}. ({luser} and {loser} are
   pronounced identically.) This word was coined around 1975 at MIT. Under ITS, when you first
   walked up to a terminal at MIT and typed Control-Z to get the computer's attention, it
   printed out some status information, including how many people were already using the
   computer; it might print "14 users", for example. Someone thought it would be a great joke
   to patch the system to print "14 losers" instead. There ensued a great controversy, as some
   of the users didn't particularly want to be called losers to their faces every time they
   used the computer. For a while several hackers struggled covertly, each changing the message
   behind the back of the others; any time you logged into the computer it was even money
   whether it would say "users" or "losers". Finally, someone tried the compromise "lusers",
   and it stuck. Later one of the ITS machines supported `luser' as a request-for-help command.
   ITS died the death in mid-1990, except as a museum piece; the usage lives on, however, and
   the term `luser' is often seen in program comments.

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