Dictionary of Technical Terms
Highlights from "The Jargon File"


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. 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.


angry fruit salad /n./ A bad user-interface design that uses too many colors.
(This term derives, of course, from the bizarre day-glo colors found in
canned fruit salad.) Too often one sees similar effects from interface
designers using color window systems such as X; there is a tendency to
create displays that are flashy and attention-getting but uncomfortable
for long-term use. 


automagically /adv./ Automatically, but in a way that, for some reason
(typically because it is too complicated, or too ugly, or perhaps even
too trivial), the speaker doesn't feel like explaining to you.
"The C-INTERCAL compiler generates C, then automagically invokes `cc(1)'
to produce an executable."  This term is quite old, going back at least
to the mid-70s and probably much earlier. The word `automagic' occurred
in advertising (for a shirt-ironing gadget) as far back as the late 1940s. 


BACB /n./ [Syracuse University: acronym] Big-Ass-Comment-Block.
Usually used to describe a comment block that is so big it either doesn't
fit on one screen or is bigger than the code it refers to.  Usually these
beasts are at least 20 lines long, and have no length limit.


BAD /B-A-D/ /adj./ [IBM: acronym, `Broken As Designed'] Said of a program
that is bogus because of bad design and misfeatures rather than because
of bugginess.


Bad Thing /n./ [from the 1930 Sellar & Yeatman parody "1066 And All That"]
Something that can't possibly result in improvement of the subject.
This term is always capitalized, as in "Replacing all of the 9600-baud
modems with bicycle couriers would be a Bad Thing". Oppose Good Thing.
British correspondents confirm that Bad Thing and Good Thing (and prob.
therefore Right Thing and Wrong Thing) come from the book referenced in
the etymology, which discusses rulers who were Good Kings but Bad Things.


bar  /n./ The second metasyntactic variable, after foo and before
baz. "Suppose we have two functions: FOO and BAR. FOO calls BAR...."
Often appended to foo to produce foobar. 


baz /n./ 1. The third metasyntactic variable "Suppose we have three
functions: FOO, BAR, and BAZ. FOO calls BAR, which calls BAZ...."
2. /interj./ A term of mild annoyance. In this usage the term is often
drawn out for 2 or 3 seconds, producing an effect not unlike the bleating
of a sheep; /baaaaaaz/. 3. Occasionally appended to foo to produce `foobaz'. 


beige toaster /n./ A Macintosh, referenced mostly to the legacy one piece
models such as the Mac Plus, SE, and Color Classic.


bells and whistles /n./ [by analogy with the toyboxes on theater organs]
Features added to a program or system to make it more flavorful from a
hacker's point of view, without necessarily adding to its utility for
its primary function. Distinguished from chrome, which is intended to
attract users.  "Now that we've got the basic program working, let's go
back and add some bells and whistles." No one seems to know what
distinguishes a bell from a whistle. 


bible /n./ 1. One of a small number of fundamental source books such as
Knuth and K&R.  2. The most detailed and authoritative reference for a
particular language, operating system, or other complex software system. 


biff /bif/ /vt./ To notify someone of incoming mail. From the BSD utility
`biff(1)', which was in turn named after a friendly golden Labrador who
used to chase frisbees in the halls at UCB while 4.2BSD was in development.
There was a legend that it had a habit of barking whenever the mailman came,
but the author of `biff' says this is not true.


Big Red Switch /n./ [IBM] The power switch on a computer, esp. the
`Emergency Pull' switch on an IBM mainframe or the power switch on an IBM
PC where it really is large and red. "This !@%$% bitty box is hung again;
time to hit the Big Red Switch." Sources at IBM report that, in tune with
the company's passion for TLAs, this is often abbreviated as `BRS'
(this has also become established on FidoNet and in the PC clone world).
It is alleged that the emergency pull switch on an IBM 360/91 actually fired
a non-conducting bolt into the main power feed; the BRSes on more recent
mainframes physically drop a block into place so that they can't be pushed
back in. People get fired for pulling them, especially inappropriately.


blinkenlights /blink'*n-li:tz/ /n./ Front-panel diagnostic lights on a
computer, esp. a dinosaur. Derives from the last word of the famous
blackletter-Gothic sign in mangled pseudo-German that once graced about
half the computer rooms in the English-speaking world. One version ran
in its entirety as follows: 

                      ACHTUNG!  ALLES LOOKENSPEEPERS!
     Das computermachine ist nicht fuer gefingerpoken und mittengrabben.
     Ist easy schnappen der springenwerk, blowenfusen und poppencorken
     mit spitzensparken.  Ist nicht fuer gewerken bei das dumpkopfen.
     Das rubbernecken sichtseeren keepen das cotten-pickenen hans in
     das pockets muss; relaxen und watchen das blinkenlichten.

This silliness dates back at least as far as 1959 at Stanford University
and had already gone international by the early 1960s, when it was reported
at London University's ATLAS computing site.


BOFH // /n./ Acronym, Bastard Operator From Hell. A system administrator
with absolutely no tolerance for lusers. "You say you need more filespace?
<massive-global-delete> Seems to me you have plenty left..." Many BOFHs
(and others who would be BOFHs if they could get away with it) hang out in
the newsgroup alt.sysadmin.recovery, although there has also been created
a top-level newsgroup hierarchy (bofh.*) of their own.  Several people have
written stories about BOFHs.  You can read BOFH stories online at:
http://www.networkweek.com/bofh


boxed comments /n./ Comments (explanatory notes attached to program
instructions) that occupy several lines by themselves; so called because in
assembler and C code they are often surrounded by a box in a style something
like this: 

  /*************************************
  *                                    *            
  * This is a boxed comment in C style *
  *                                    *
  *************************************/

Common variants of this style omit the asterisks closing the right side of
the box. The sparest variant omits all but the comment delimiters themselves;
the `box' is implied.


Brooks's Law /prov./ "Adding manpower to a late software project makes it
later" -- a result of the fact that the expected advantage from splitting
work among N programmers is O(N) (that is, proportional to N), but the
complexity and communications cost associated with coordinating and then
merging their work is O(N^2) (that is, proportional to the square of N).
The quote is from Fred Brooks, a manager of IBM's OS/360 project and author
of "The Mythical Man-Month" (Addison-Wesley, 1975, ISBN 0-201-00650-2),
an excellent early book on software engineering. The myth in question has
been most tersely expressed as "Programmer time is fungible" and Brooks
established conclusively that it is not. Hackers have never forgotten his
advice; too often, management still does.


C /n./ 1. The third letter of the English alphabet. 2. ASCII 1000011.
3. The name of a programming language designed by Dennis Ritchie during the
early 1970s and immediately used to reimplement Unix; so called because many
features derived from an earlier compiler named `B' in commemoration of *its*
parent, BCPL. (BCPL was in turn descended from an earlier Algol-derived
language, CPL.) Before Bjarne Stroustrup settled the question by designing
C++, there was a humorous debate over whether C's successor should be named
`D' or `P'. C became immensely popular outside Bell Labs after about 1980 and
is now the dominant language in systems and microcomputer applications
programming.  C is often described, with a mixture of fondness and disdain
varying according to the speaker, as "a language that combines all the
elegance and power of assembly language with all the readability and
maintainability of assembly language". 


cd tilde /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,
`cd ~coffee' would mean "I'm going to the coffee machine." 


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?"

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. 


code police /n./ [by analogy with George Orwell's `thought police']
A mythical team of Gestapo-like storm troopers that might burst into one's
office and arrest one for violating programming style rules. May be used
either seriously, to underline a claim that a particular style violation
is dangerous, or ironically, to suggest that the practice under discussion
is condemned mainly by anal-retentive weenies. "Dike out that goto or the
code police will get you!"


control-C /vi./ "Stop whatever you are doing." From the interrupt
character used on many operating systems to abort a running program.


control-O /vi./ "Stop talking." From the character used on some operating
systems to abort output but allow the program to keep on running.
Generally means that you are not interested in hearing anything more from
that person, at least on that topic; a standard response to someone who is
flaming.


control-Q /vi./ "Resume." From the ASCII DC1 or XON character, used to undo
a previous control-S. 


control-S /vi./ "Stop talking for a second.  Suspend."  Control-S differs
from control-O in that the person is asked to stop talking (perhaps because
you are on the phone) but will be allowed to continue when you're ready to
listen to him -- as opposed to control-O, which has more of the meaning of
"Shut up." 


copious free time /n./ [Apple; orig. fr. the intro to Tom Lehrer's song
"It Makes A Fellow Proud To Be A Soldier"] 1. [used ironically to indicate
the speaker's lack of the quantity in question] A mythical schedule slot
for accomplishing tasks held to be unlikely or impossible. Sometimes used to
indicate that the speaker is interested in accomplishing the task, but
believes that the opportunity will not arise. "I'll implement the automatic
layout stuff in my copious free time." 2. [Archly] Time reserved for bogus or
otherwise idiotic tasks, such as implementation of chrome, or the stroking of
suits. "I'll get back to him on that feature in my copious free time." 


core /n./ Main storage or RAM. Dates from the days of ferrite-core memory;
now archaic as techspeak most places outside IBM, but also still used in
the Unix community and by old-time hackers or those who would sound like
them. Some derived idioms are quite current; `in core', for example, means
`in memory' (as opposed to `on disk'),


core dump /n./ [common Iron Age jargon, preserved by Unix]
1. [techspeak] A copy of the contents of core, produced when a process is
aborted by certain kinds of internal error. 2. By extension, used for humans
passing out, vomiting, or registering extreme shock. "He dumped core. All
over the floor. What a mess." "He heard about X and dumped core."
3. Occasionally used for a human rambling on pointlessly at great length;
esp. in apology: "Sorry, I dumped core on you". 4. A recapitulation of
knowledge. Hence, spewing all one knows about a topic (syn. brain dump), esp.
in a lecture or answer to an exam question. "Short, concise answers are
better than core dumps" (from the instructions to an exam at Columbia).


cough and die /v./ Syn. barf. Connotes that the program is throwing its hands
up by design rather than because of a bug or oversight. "The parser saw a
control-A in its input where it was looking for a printable, so it coughed
and died."


cycle server /n./ A powerful machine that exists primarily for running
large compute-, disk-, or memory-intensive jobs. Implies that interactive
tasks such as editing are done on other machines on the network.


DED /D-E-D/ /n./ Dark-Emitting Diode (that is, a burned-out LED). In the
early 1970s both Signeticsand Texas instruments released DED spec sheets
as an April fools jokes (suggested uses included "as a power-off indicator"). 


deep magic /n./ [poss. from C. S. Lewis's "Narnia" books] An awesomely arcane
technique central to a program or system, esp. one neither generally published
nor available to hackers at large; one that could only have been composed by
a true wizard. Compiler optimization techniques and many aspects of OS design
used to be deep magic; many techniques in cryptography, signal processing,
graphics, and AI still are.  Esp. found in comments of the form
"Deep magic begins here...".


deep space /n./ 1. Describes the notional location of any program that has
gone off the trolley. Esp. used of programs that just sit there silently
grinding long after either failure or some output is expected. "Uh oh.
I should have gotten a prompt ten seconds ago. The program's in deep space
somewhere."  2. The metaphorical location of a human so dazed and/or confused
or caught up in some esoteric form of bogosity that he or she no longer
responds coherently to normal communication.


Dilbert /n./ Name and title character of a comic strip nationally syndicated
in the U.S. and enormously popular among hackers. Dilbert is an archetypical
engineer-nerd who works at an anonymous high-technology company; the strips
present a lacerating satire of insane working conditions and idiotic
management practices all too readily recognized by hackers. Adams, who spent
nine years in cube 4S700R at Pacific Bell (not DEC as often reported), often
remarks that he has never been able to come up with a fictional management
blunder that his correspondents didn't quickly either report to have actually
happened or top with a similar but even more bizarre incident. In 1996 Adams
distilled his insights into the collective psychology of businesses into a
hardcover book "The Dilbert Principle" (HarperCollins, ISBN 0-887-30787-6).


dinosaur /n./ 1. Any hardware requiring raised flooring and special power.
Used especially of old minis and mainframes, in contrast with newer
microprocessor-based machines. In a famous quote from the 1988 Unix EXPO,
Bill Joy compared the liquid-cooled mainframe in the massive IBM display with
a grazing dinosaur "with a truck outside pumping its bodily fluids through it"
IBM was not amused.


dinosaur pen /n./ A traditional mainframe computer room complete with raised
flooring, special power, its own ultra-heavy-duty air conditioning,
and a side order of Halon fire extinguishers.


dogcow /n./  The dogcow is a semi-legendary creature that lurks in the depths
of the Macintosh Technical Notes Hypercard stack V3.1. The full story of the
dogcow is told in technical note #31 (the particular dogcow illustrated is
properly named `Clarus'). Option-shift-click will cause it to emit a
characteristic `Moof!' or `!fooM' sound. *Getting* to tech note 31 is the
hard part; to discover how to do that, one must needs examine the stack
script with a hackerly eye. Clue: rot13 is involved. A dogcow also appears
if you choose `Page Setup...' with a LaserWriter selected and click on the
`Options' button. 


Don't do that, then! /imp./ [from an old doctor's office joke about a
patient with a trivial complaint] Stock response to a user complaint.
"When I type control-S, the whole system comes to a halt for thirty
seconds." "Don't do that, then!" (or "So don't do that!").


drop on the floor /vt./ To react to an error condition by silently
discarding messages or other valuable data. "The gateway ran out of
memory, so it just started dropping packets on the floor." Also frequently
used of faulty mail and netnews relay sites that lose messages.


Duff's device /n./ The most dramatic use yet seen of fall through in C,
invented by Tom Duff when he was at Lucasfilm. Trying to bum all the
instructions he could out of an inner loop that copied data serially
onto an output port, he decided to unroll it. He then realized that
the unrolled version could be implemented by *interlacing* the structures
of a switch and a loop: 

        register n = (count + 7) / 8;      /* count > 0 assumed */

        switch (count % 8)
        {
        case 0:        do {  *to = *from++;
        case 7:              *to = *from++;
        case 6:              *to = *from++;
        case 5:              *to = *from++;
        case 4:              *to = *from++;
        case 3:              *to = *from++;
        case 2:              *to = *from++;
        case 1:              *to = *from++;
                           } while (--n > 0);
        }

Shocking though it appears to all who encounter it for the first time,
the device is actually perfectly valid, legal C. C's default fall through
in case statements has long been its most controversial single feature;
Duff observed that "This code forms some sort of argument in that debate,
but I'm not sure whether it's for or against." 


#f [from scheme terminology for `false'] No. Used in reply to a question.
In scheme, the constant #f means `false'.

feature shock /n./ [from Alvin Toffler's book title "Future Shock"]
A user's (or programmer's!) confusion when confronted with a package
that has too many features and poor introductory material. 


FIXME /imp./ A standard tag often put in C comments near a piece of
code that needs work. The point of doing so is that a `grep' or a
similar pattern-matching tool can find all such places quickly. 


foo /foo/ 1. /interj./ Term of disgust. 2. Used very generally as a sample
name for absolutely anything, esp. programs and files (esp. scratch files).
3. First on the standard list of metasyntactic variables used in syntax
examples.


foobar /n./ Another common metasyntactic variable; see foo. Hackers do
*not* generally use this to mean FUBAR in either the slang or jargon sense.


for free /adj./ Said of a capability of a programming language or hardware
that is available by its design without needing cleverness to implement: "In
APL, we get the matrix operations for free." "And owing to the way revisions
are stored in this system, you get revision trees for free." The term
usually refers to a serendipitous feature of doing things a certain way,
but it may refer to an intentional but secondary feature.


FUBAR /n./ The Failed UniBus Address Register in a VAX. A good example of
how jargon can occasionally be snuck past the suits.


Godwin's Law /prov./ [Usenet] "As a Usenet discussion grows longer, the
probability of a comparison involving Nazis or Hitler approaches one."
There is a tradition in many groups that, once this occurs, that thread is
over, and whoever mentioned the Nazis has automatically lost whatever
argument was in progress. Godwin's Law thus practically guarantees the
existence of an upper bound on thread length in those groups. 


Godzillagram /god-zil'*-gram/ /n./ [from Japan's national hero]
1. A network packet that in theory is a broadcast to every machine in the
universe.  The typical case is an IP datagram whose destination IP address
is [255.255.255.255]. Fortunately, few gateways are foolish enough to attempt
to implement this case! 2. A network packet of maximum size.
An IP Godzillagram has 65,536 octets.


Hackintosh /n./ 1. An Apple Lisa that has been hacked into emulating a
Macintosh (also called a `Mac XL'). 2. A Macintosh assembled from parts
theoretically belonging to different models in the line. 


hello, world /interj./ 1. The canonical minimal test message in the
C/Unix universe. 2. Any of the minimal programs that emit this message.
Traditionally, the first program a C coder is supposed to write in a new
environment is one that just prints "hello, world" to standard output
(and indeed it is the first example program in K&R). Environments that
generate an unreasonably large executable for this trivial test or which
require a hairy compiler-linker invocation to generate it are considered
to lose (see X). 3. Greeting uttered by a hacker making an entrance or
requesting information from anyone present.
"Hello, world! Is the VAX back up yet?" 


hexadecimal : /n./ Base 16. Coined in the early 1960s to replace earlier
`sexadecimal', which was too racy and amusing for stuffy IBM, and later
adopted by the rest of the industry. 


IBM discount /n./ A price increase. Outside IBM, this derives from the
common perception that IBM products are generally overpriced; inside, it
is said to spring from a belief that large numbers of IBM employees living
in an area cause prices to rise. 


infinite loop /n./ One that never terminates (that is, the machine spins
or buzzes forever and goes catatonic), either be careless programming or
on purpose for event driven interfaces.  Rumor has it that the Cray located
at Apple Computer Headquarters (1 Infinite Loop, Cupertino California) is
so fast that it can do an infinite loop in 6 seconds.


insanely great /adj./ [Mac community, from Steve Jobs; also BSD Unix people
via Bill Joy] Something so incredibly elegant that it is imaginable only
to someone possessing the most puissant of hacker-natures. 


job security /n./ When some piece of code is written in a particularly
obscure fashion, and no good reason (such as time or space optimization)
can be discovered, it is often said that the programmer was attempting to
increase his job security (i.e., by making himself indispensable for
maintenance).  This sour joke seldom has to be said in full; if two hackers
are looking over some code together and one points at a section and says
"job security", the other one may just nod. 


jump off into never-never land /v./ [from J. M. Barrie's "Peter Pan"]
Same as branch to Fishkill, but more common in technical cultures associated
with non-IBM computers that use the term `jump' rather than `branch'.


K&R [Kernighan and Ritchie] /n./ Brian Kernighan and Dennis Ritchie's book
"The C Programming Language", esp. the classic and influential first edition
(Prentice-Hall 1978; ISBN 0-113-110163-3). Syn. White Book, Old Testament.


Knights of the Lambda Calculus /n./ A semi-mythical organization of wizardly
LISP and Scheme hackers. The name refers to a mathematical formalism invented
by Alonzo Church, with which LISP is intimately connected. There is no
enrollment list and the criteria for induction are unclear, but one
well-known LISPer has been known to give out buttons and, in general,
the *members* know who they are.... 


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.


Life is hard /prov./ [XEROX PARC] This phrase has two possible
interpretations: (1) "While your suggestion may have some merit, I will
behave as though I hadn't heard it." (2) "While your suggestion has obvious
merit, equally obvious circumstances prevent it from being seriously
considered."  The charm of the phrase lies precisely in this subtle but
important ambiguity. 


Liquiffeine /n/[Syracuse University] Liquid caffeine.  A must for late
night programming sessions.  Most often a combination of coffee, espresso,
or Mountain Dew.


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. Recently
(1994) an inferior imitation of these has been put in circulation with a red
corporate logo added. 


magic /adj./ 1. As yet unexplained, or too complicated to explain; compare
automagically and (Arthur C.) Clarke's Third Law: "Any sufficiently
advanced technology is indistinguishable from magic." "TTY echoing is
controlled by a large number of magic bits." "This routine magically computes
the parity of an 8-bit byte in three instructions." 2. Characteristic of
something that works although no one really understands why (this is
especially called black magic). 3. [Stanford] A feature not generally
publicized that allows something otherwise impossible, or a feature formerly
in that category but now unveiled.


metasyntactic variable /n./ A name used in examples and understood to
stand for whatever thing is under discussion, or any random member of a
class of things under discussion. The word foo is the canonical example.
To avoid confusion, hackers never (well, hardly ever) use `foo' or other
words like it as permanent names for anything. In filenames, a common
convention is that any filename beginning with a metasyntactic-variable
name is a scratch file that may be deleted at any time. 

To some extent, the list of one's preferred metasyntactic variables is a
cultural signature. They occur both in series (used for related groups of
variables or objects) and as singletons. Here are a few common signatures: 

     foo, bar, baz, quux, quuux, quuuux...:
          MIT/Stanford usage, now found everywhere (thanks largely to
          early versions of this lexicon!).  At MIT (but not at
          Stanford), baz dropped out of use for a while in the 1970s
          and '80s. A common recent mutation of this sequence inserts
          qux before quux.
     bazola, ztesch:
          Stanford (from mid-'70s on).
     foo, bar, thud, grunt:
          This series was popular at CMU.  Other CMU-associated
          variables include gorp.
     foo, bar, fum:
          This series is reported to be common at XEROX PARC.
     fred, barney:
          See the entry for fred.  These tend to be Britishisms.
     corge, grault, flarp:
          Popular at Rutgers University and among GOSMACS hackers.
     zxc, spqr, wombat:
          Cambridge University (England).
     shme
          Berkeley, GeoWorks, Ingres.  Pronounced /shme/ with a short
          /e/.
     snork
          Brown University, early 1970s.
     foo, bar, zot
          Helsinki University of Technology, Finland.
     blarg, wibble
          New Zealand.
     toto, titi, tata, tutu
          France.
     pippo, pluto, paperino
          Italy.  Pippo /pee'po/ and Paperino /pa-per-ee'-no/ are the
          Italian names for Goofy and Donald Duck.
     aap, noot, mies
          The Netherlands.  These are the first words a child used to
          learn to spell on a Dutch spelling board.

Of all these, only `foo' and `bar' are universal (and baz nearly so).
The compounds foobar and `foobaz' also enjoy very wide currency. 


Moof /moof/ [Macintosh users] 1. /n./ The call of a semi-legendary creature,
properly called the dogcow. (Some previous versions of this entry
claimed, incorrectly, that Moof was the name of the *creature*.)
2. /adj./ Used to flag software that's a hack, something untested and
on the edge. On one Apple CD-ROM, certain folders such as
"Tools & Apps (Moof!)" and "Development Platforms (Moof!)",
are so marked to indicate that they contain software not fully tested or
sanctioned by the powers that be. When you open these folders you cross the
boundary into hackerland. 3. /v./ On the Microsoft Network, the term `moof'
has gained popularity as a verb meaning `to be suddenly disconnected by the
system'. One might say "I got moofed". 


Moore's Law /morz law/ /prov./ The observation that the logic density of
silicon integrated circuits has closely followed the curve (bits per square
inch) = 2^((t - 1962)) where t is time in years; that is, the amount of
information storable on a given amount of silicon has roughly doubled every
year since the technology was invented. This relation, first uttered in 1964
by semiconductor engineer Gordon Moore (who co-founded Intel four years
later) held until the late 1970s, at which point the doubling period
slowed to 18 months. It remained at that value through time of writing
(late 1995).


mu /moo/ The correct answer to the classic trick question "Have you stopped
beating your wife yet?". Assuming that you have no wife or you have
never beaten your wife, the answer "yes" is wrong because it implies that
you used to beat your wife and then stopped, but "no" is worse because it
suggests that you have one and are still beating her. According to various
Discordians and Douglas Hofstadter the correct answer is usually "mu", a
Japanese word alleged to mean "Your question cannot be answered because it
depends on incorrect assumptions". Hackers tend to be sensitive to
logical inadequacies in language, and many have adopted this suggestion
with enthusiasm. The word `mu' is actually from Chinese, meaning `nothing';
it is used in mainstream Japanese in that sense, but native speakers do not
recognize the Discordian question-denying use. It almost certainly derives
from overgeneralization of the answer in the following well-known Rinzei Zen
teaching riddle: 
     A monk asked Joshu, "Does a dog have the Buddha nature?"  Joshu
     retorted, "Mu!"


Murphy's Law /prov./ The correct, *original* Murphy's Law reads:
"If there are two or more ways to do something, and one of those ways can
result in a catastrophe, then someone will do it." This is a principle of
defensive design, cited here because it is usually given in mutant forms less
descriptive of the challenges of design for lusers. For example, you don't
make a two-pin plug symmetrical and then label it `THIS WAY UP'; if it
matters which way it is plugged in, then you make the design asymmetrical.
Edward A. Murphy, Jr. was one of the engineers on the rocket-sled experiments
that were done by the U.S. Air Force in 1949 to test human acceleration
tolerances (USAF project MX981). One experiment involved a set of 16
accelerometers mounted to different parts of the subject's body.  There were
two ways each sensor could be glued to its mount, and somebody methodically
installed all 16 the wrong way around. Murphy then made the original form of
his pronouncement, which the test subject (Major John Paul Stapp) quoted at
a news conference a few days later.   Within months `Murphy's Law' had spread
to various technical cultures connected to aerospace engineering. Before too
many years had gone by variants had passed into the popular imagination,
changing as they went. Most of these are variants on "Anything that can go
wrong, will"; this is correctly referred to as Finagle's Law. The memetic
drift apparent in these mutants clearly demonstrates Murphy's Law acting on
itself! 


mutter /vt./ To quietly enter a command not meant for the ears, eyes, or
fingers of ordinary mortals. Often used in `mutter an incantation'.


New Testament /n./ [C programmers] The second edition of K&R's
"The C Programming Language" (Prentice-Hall, 1988; ISBN 0-13-110362-8),
describing ANSI Standard C. This version is also called `K&R2'.


Old Testament /n./ [C programmers] The first edition of K&R,
the sacred text describing Classic C. 


ooblick /oo'blik/ /n./ [from Dr. Seuss "Bartholomew and the Oobleck";
the spelling `oobleck' is still current in the mainstream] A bizarre
semi-liquid sludge made from cornstarch and water. Enjoyed among hackers
who make batches during playtime at parties for its amusing and
extremely non-Newtonian behavior; it pours and splatters, but resists
rapid motion like a solid and will even crack when hit by a hammer.
Often found near lasers.
Here is a field-tested ooblick recipe contributed by GLS: 
1 cup cornstarch 1 cup baking soda 3/4 cup water N drops of food coloring 
This recipe isn't quite as non-Newtonian as a pure cornstarch ooblick,
but has an appropriately slimy feel.   Some, however, insist that the notion
of an ooblick *recipe* is far too mechanical, and that it is best to add the
water in small increments so that the various mixed states the cornstarch
goes through as it *becomes* ooblick can be grokked in fullness by many hands.


parse [from linguistic terminology] /vt./ 1. To determine the syntactic
structure of a sentence or other utterance (close to the standard English
meaning). "That was the one I saw you." "I can't parse that."
2. More generally, to understand or comprehend. "It's very simple; you
just kretch the glims and then aos the zotz." "I can't parse that."


peon /n./ A person with no special privileges on a computer system.
"I can't create an account on *foovax* for you; I'm only a peon there." 


pizza box /n./ [Sun] The largish thin box housing the electronics in
(especially Sun) desktop workstations, so named because of its size and
shape and the dimpled pattern that looks like air holes.
Two meg single-platter removable disk packs used to be called pizzas,
and the huge drive they were stuck into was referred to as a pizza oven.
It's an index of progress that in the old days just the disk was pizza-sized,
while now the entire computer is. 


point-and-drool interface /n./ Parody of the techspeak term
`point-and-shoot interface', describing a windows, icons, and
mouse-based interface such as is found on the Macintosh. The
implication, of course, is that such an interface is only suitable
for idiots.


power cycle /vt./ (also, `cycle power' or just `cycle') To power off a
machine and then power it on immediately, with the intention of clearing
some kind of hung or gronked state or all contents of RAM.


programming fluid /n./ 1. Coffee. 2. Cola. 3. Any caffeinacious stimulant.
Many hackers consider these essential for those all-night hacking runs.


read-only user /n./ Describes a luser who uses computers almost exclusively
for reading Usenet, bulletin boards, and/or email, rather than writing
code or purveying useful information.


Right Thing /n./ That which is *compellingly* the correct or appropriate
thing to use, do, say, etc. Often capitalized, always emphasized in speech
as though capitalized. Use of this term often implies that in fact reasonable
people may disagree. "What's the right thing for LISP to do when it sees
`(mod a 0)'? Should it return `a', or give a divide-by-0 error?"


second-system effect /n./ (sometimes `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.


segmentation fault /n./ [Unix] 1. An error in which a running program
attempts to access memory not allocated to it and core dumps 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. 


sneakernet /snee'ker-net/ /n./ Term used (generally with ironic intent) for
transfer of electronic information by physically carrying tape, disks, or
some other media from one machine to another. "Never underestimate the
bandwidth of a station wagon filled with magtape, or a 747 filled with
CD-ROMs." Also called `Tennis-Net', `Armpit-Net', `Floppy-Net' or `Shoenet'. 


speedometer /n./ A pattern of lights displayed on a linear set of LEDs
(today) or nixie tubes (yesterday, on ancient mainframes). The pattern
is shifted left every N times the operating system goes through its main
loop. A swiftly moving pattern indicates that the system is mostly idle;
the speedometer slows down as the system becomes overloaded. The speedometer
on Sun Microsystems hardware bounces back and forth like the eyes on one
of the Cylons from the wretched "Battlestar Galactica" TV series. 
Historical note: One computer, the GE 600 (later Honeywell 6000) actually
had an *analog* speedometer on the front panel, calibrated in instructions
executed per second. 


star out /v./ [University of York, England] To replace a user's encrypted
password in /etc/passwd with a single asterisk. Under Unix this is not a
legal encryption of any password; hence the user is not permitted to log in.
In general, accounts like adm, news, and daemon are permanently "starred out";
occasionally a real user might have the this inflicted upon him/her as a
punishment, e.g. "Graham was starred out for playing Omega in working
hours". Also occasionally known as The Order Of The Gold Star in this
context. "Don't do that, or you'll be awarded the Order of the Gold Star..."


#t [from scheme terminology for `true'] Yes. Used in reply to a question.
In scheme, the constant #t means `true'.


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).
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."


You are not expected to understand this [Unix] /cav./ The canonical comment
describing something magic or too complicated to bother explaining properly.
From an infamous comment in the context-switching code of the V6 Unix kernel. 


zeroth /zee'rohth/ /adj./ First. Among software designers, comes from C's
and LISP's 0-based indexing of arrays. Hardware people also tend to start
counting at 0 instead of 1; this is natural since, e.g., the 256 states of
8 bits correspond to the binary numbers 0, 1, ..., 255 and the digital
devices known as `counters' count in this way.   Hackers and computer
scientists often like to call the first chapter of a publication `Chapter 0'
especially if it is of an introductory nature (one of the classic instances
was in the First Edition of K&R). In recent years this trait has also been
observed among many pure mathematicians (who have an independent tradition
of numbering from 0). Zero-based numbering tends to reduce fencepost errors,
though it cannot eliminate them entirely. 


/dev/null   A place in the Unix system where any data written or redirected
to it is discarded immediately.  Essentially, a black hole.


/dev/zero   A place in the Unix system that spits out an infinite supply of
blank or meaningless data.  Essentially, a white hole.