Books: The New Hacker\'s Dictionary version 4.2.2
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Various editors >> The New Hacker\'s Dictionary version 4.2.2
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* [9610]Ob-:
* [9611]Obfuscated C Contest:
* [9612]obi-wan error:
* [9613]Objectionable-C:
* [9614]obscure:
* [9615]octal forty:
* [9616]off the trolley:
* [9617]off-by-one error:
* [9618]offline:
* [9619]ogg:
* [9620]-oid:
* [9621]old fart:
* [9622]Old Testament:
* [9623]on the gripping hand:
* [9624]one-banana problem:
* [9625]one-line fix:
* [9626]one-liner wars:
* [9627]ooblick:
* [9628]op:
* [9629]open:
* [9630]open source:
* [9631]open switch:
* [9632]operating system:
* [9633]optical diff:
* [9634]optical grep:
* [9635]optimism:
* [9636]Oracle the:
* [9637]Orange Book:
* [9638]oriental food:
* [9639]orphan:
* [9640]orphaned i-node:
* [9641]orthogonal:
* [9642]OS:
* [9643]OS/2:
* [9644]OSS:
* [9645]OSU:
* [9646]OTOH:
* [9647]out-of-band:
* [9648]overclock:
* [9649]overflow bit:
* [9650]overflow pdl:
* [9651]overrun:
* [9652]overrun screw:
_________________________________________________________________
Node:Ob-, Next:[9653]Obfuscated C Contest, Previous:[9654]nyetwork,
Up:[9655]= O =
Ob- /ob/ pref.
Obligatory. A piece of [9656]netiquette acknowledging that the author
has been straying from the newsgroup's charter topic. For example, if
a posting in alt.sex is a response to a part of someone else's posting
that has nothing particularly to do with sex, the author may append
`ObSex' (or `Obsex') and toss off a question or vignette about some
unusual erotic act. It is considered a sign of great [9657]winnitude
when one's Obs are more interesting than other people's whole
postings.
_________________________________________________________________
Node:Obfuscated C Contest, Next:[9658]obi-wan error,
Previous:[9659]Ob-, Up:[9660]= O =
Obfuscated C Contest n.
(in full, the `International Obfuscated C Code Contest', or IOCCC) An
annual contest run since 1984 over Usenet by Landon Curt Noll and
friends. The overall winner is whoever produces the most unreadable,
creative, and bizarre (but working) C program; various other prizes
are awarded at the judges' whim. C's terse syntax and
macro-preprocessor facilities give contestants a lot of maneuvering
room. The winning programs often manage to be simultaneously (a)
funny, (b) breathtaking works of art, and (c) horrible examples of how
not to code in C.
This relatively short and sweet entry might help convey the flavor of
obfuscated C:
/*
* HELLO WORLD program
* by Jack Applin and Robert Heckendorn, 1985
* (Note: depends on being able to modify elements of argv[],
* which is not guaranteed by ANSI and often not possible.)
*/
main(v,c)char**c;{for(v[c++]="Hello, world!\n)";
(!!c)[*c]&&(v--||--c&&execlp(*c,*c,c[!!c]+!!c,!c));
**c=!c)write(!!*c,*c,!!**c);}
Here's another good one:
/*
* Program to compute an approximation of pi
* by Brian Westley, 1988
* (requires pcc macro concatenation; try gcc -traditional-cpp)
*/
#define _ -F<00||--F-OO--;
int F=00,OO=00;
main(){F_OO();printf("%1.3f\n",4.*-F/OO/OO);}F_OO()
{
_-_-_-_
_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_-_-_-_-_
_-_-_-_-_-_-_-_
_-_-_-_
}
Note that this program works by computing its own area. For more
digits, write a bigger program. See also [9661]hello world.
The IOCCC has an official home page at [9662]http://www.ioccc.org.
_________________________________________________________________
Node:obi-wan error, Next:[9663]Objectionable-C,
Previous:[9664]Obfuscated C Contest, Up:[9665]= O =
obi-wan error /oh'bee-won` er'*r/ n.
[RPI, from `off-by-one' and the Obi-Wan Kenobi character in "Star
Wars"] A loop of some sort in which the index is off by 1. Common when
the index should have started from 0 but instead started from 1. A
kind of [9666]off-by-one error. See also [9667]zeroth.
_________________________________________________________________
Node:Objectionable-C, Next:[9668]obscure, Previous:[9669]obi-wan
error, Up:[9670]= O =
Objectionable-C n.
Hackish take on "Objective-C", the name of an object-oriented dialect
of C in competition with the better-known C++ (it is used to write
native applications on the NeXT machine). Objectionable-C uses a
Smalltalk-like syntax, but lacks the flexibility of Smalltalk method
calls, and (like many such efforts) comes frustratingly close to
attaining the [9671]Right Thing without actually doing so.
_________________________________________________________________
Node:obscure, Next:[9672]octal forty, Previous:[9673]Objectionable-C,
Up:[9674]= O =
obscure adj.
Used in an exaggeration of its normal meaning, to imply total
incomprehensibility. "The reason for that last crash is obscure." "The
find(1) command's syntax is obscure!" The phrase `moderately obscure'
implies that something could be figured out but probably isn't worth
the trouble. The construction `obscure in the extreme' is the
preferred emphatic form.
_________________________________________________________________
Node:octal forty, Next:[9675]off the trolley, Previous:[9676]obscure,
Up:[9677]= O =
octal forty /ok'tl for'tee/ n.
Hackish way of saying "I'm drawing a blank." Octal 40 is the
[9678]ASCII space character, 0100000; by an odd coincidence, [9679]hex
40 (01000000) is the [9680]EBCDIC space character. See [9681]wall.
_________________________________________________________________
Node:off the trolley, Next:[9682]off-by-one error,
Previous:[9683]octal forty, Up:[9684]= O =
off the trolley adj.
Describes the behavior of a program that malfunctions and goes
catatonic, but doesn't actually [9685]crash or abort. See
[9686]glitch, [9687]bug, [9688]deep space, [9689]wedged.
This term is much older than computing, and is (uncommon) slang
elsewhere. A trolley is the small wheel that trolls, or runs against,
the heavy wire that carries the current to run a streetcar. It's at
the end of the long pole (the trolley pole) that reaches from the roof
of the streetcar to the overhead line. When the trolley stops making
contact with the wire (from passing through a switch, going over bumpy
track, or whatever), the streetcar comes to a halt, (usually) without
crashing. The streetcar is then said to be off the trolley, or off the
wire. Later on, trolley came to mean the streetcar itself. Since
streetcars became common in the 1890s, the term is more than 100 years
old. Nowadays, trolleys are only seen on historic streetcars, since
modern streetcars use pantographs to contact the wire.
_________________________________________________________________
Node:off-by-one error, Next:[9690]offline, Previous:[9691]off the
trolley, Up:[9692]= O =
off-by-one error n.
[common] Exceedingly common error induced in many ways, such as by
starting at 0 when you should have started at 1 or vice-versa, or by
writing < N instead of <= N or vice-versa. Also applied to giving
something to the person next to the one who should have gotten it.
Often confounded with [9693]fencepost error, which is properly a
particular subtype of it.
_________________________________________________________________
Node:offline, Next:[9694]ogg, Previous:[9695]off-by-one error,
Up:[9696]= O =
offline adv.
Not now or not here. "Let's take this discussion offline."
Specifically used on [9697]Usenet to suggest that a discussion be
moved off a public newsgroup to email.
_________________________________________________________________
Node:ogg, Next:[9698]-oid, Previous:[9699]offline, Up:[9700]= O =
ogg /og/ v.
[CMU] 1. In the multi-player space combat game Netrek, to execute
kamikaze attacks against enemy ships which are carrying armies or
occupying strategic positions. Named during a game in which one of the
players repeatedly used the tactic while playing Orion ship G, showing
up in the player list as "Og". This trick has been roundly denounced
by those who would return to the good old days when the tactic of
dogfighting was dominant, but as Sun Tzu wrote, "What is of supreme
importance in war is to attack the enemy's strategy, not his tactics."
However, the traditional answer to the newbie question "What does ogg
mean?" is just "Pick up some armies and I'll show you." 2. In other
games, to forcefully attack an opponent with the expectation that the
resources expended will be renewed faster than the opponent will be
able to regain his previous advantage. Taken more seriously as a
tactic since it has gained a simple name. 3. To do anything
forcefully, possibly without consideration of the drain on future
resources. "I guess I'd better go ogg the problem set that's due
tomorrow." "Whoops! I looked down at the map for a sec and almost
ogged that oncoming car."
_________________________________________________________________
Node:-oid, Next:[9701]old fart, Previous:[9702]ogg, Up:[9703]= O =
-oid suff.
[from Greek suffix -oid = `in the image of'] 1. Used as in mainstream
slang English to indicate a poor imitation, a counterfeit, or some
otherwise slightly bogus resemblance. Hackers will happily use it with
all sorts of non-Greco/Latin stem words that wouldn't keep company
with it in mainstream English. For example, "He's a nerdoid" means
that he superficially resembles a nerd but can't make the grade; a
`modemoid' might be a 300-baud box (Real Modems run at 28.8 or up); a
`computeroid' might be any [9704]bitty box. The word `keyboid' could
be used to describe a [9705]chiclet keyboard, but would have to be
written; spoken, it would confuse the listener as to the speaker's
city of origin. 2. More specifically, an indicator for `resembling an
android' which in the past has been confined to science-fiction fans
and hackers. It too has recently (in 1991) started to go mainstream
(most notably in the term `trendoid' for victims of terminal hipness).
This is probably traceable to the popularization of the term
[9706]droid in "Star Wars" and its sequels. (See also [9707]windoid.)
Coinages in both forms have been common in science fiction for at
least fifty years, and hackers (who are often SF fans) have probably
been making `-oid' jargon for almost that long [though GLS and I can
personally confirm only that they were already common in the mid-1970s
--ESR].
_________________________________________________________________
Node:old fart, Next:[9708]Old Testament, Previous:[9709]-oid,
Up:[9710]= O =
old fart n.
Tribal elder. A title self-assumed with remarkable frequency by (esp.)
Usenetters who have been programming for more than about 25 years;
often appears in [9711]sig blocks attached to Jargon File
contributions of great archeological significance. This is a term of
insult in the second or third person but one of pride in first person.
_________________________________________________________________
Node:Old Testament, Next:[9712]on the gripping hand,
Previous:[9713]old fart, Up:[9714]= O =
Old Testament n.
[C programmers] The first edition of [9715]K&R, the sacred text
describing [9716]Classic C.
_________________________________________________________________
Node:on the gripping hand, Next:[9717]one-banana problem,
Previous:[9718]Old Testament, Up:[9719]= O =
on the gripping hand
In the progression that starts "On the one hand..." and continues "On
the other hand..." mainstream English may add "on the third hand..."
even though most people don't have three hands. Among hackers, it is
just as likely to be "on the gripping hand". This metaphor supplied
the title of Larry Niven & Jerry Pournelle's 1993 SF novel "The
Gripping Hand" which involved a species of hostile aliens with three
arms (the same species, in fact, referenced in [9720]juggling eggs).
As with [9721]TANSTAAFL and [9722]con, this usage one of the
naturalized imports from SF fandom frequently observed among hackers.
_________________________________________________________________
Node:one-banana problem, Next:[9723]one-line fix, Previous:[9724]on
the gripping hand, Up:[9725]= O =
one-banana problem n.
At mainframe shops, where the computers have operators for routine
administrivia, the programmers and hardware people tend to look down
on the operators and claim that a trained monkey could do their job.
It is frequently observed that the incentives that would be offered
said monkeys can be used as a scale to describe the difficulty of a
task. A one-banana problem is simple; hence, "It's only a one-banana
job at the most; what's taking them so long?"
At IBM, folklore divides the world into one-, two-, and three-banana
problems. Other cultures have different hierarchies and may divide
them more finely; at ICL, for example, five grapes (a bunch) equals a
banana. Their upper limit for the in-house [9726]sysapes is said to be
two bananas and three grapes (another source claims it's three bananas
and one grape, but observes "However, this is subject to local
variations, cosmic rays and ISO"). At a complication level any higher
than that, one asks the manufacturers to send someone around to check
things.
See also [9727]Infinite-Monkey Theorem.
_________________________________________________________________
Node:one-line fix, Next:[9728]one-liner wars,
Previous:[9729]one-banana problem, Up:[9730]= O =
one-line fix n.
Used (often sarcastically) of a change to a program that is thought to
be trivial or insignificant right up to the moment it crashes the
system. Usually `cured' by another one-line fix. See also [9731]I
didn't change anything!
_________________________________________________________________
Node:one-liner wars, Next:[9732]ooblick, Previous:[9733]one-line fix,
Up:[9734]= O =
one-liner wars n.
A game popular among hackers who code in the language APL (see
[9735]write-only language and [9736]line noise). The objective is to
see who can code the most interesting and/or useful routine in one
line of operators chosen from APL's exceedingly [9737]hairy primitive
set. A similar amusement was practiced among [9738]TECO hackers and is
now popular among [9739]Perl aficionados.
Ken Iverson, the inventor of APL, has been credited with a one-liner
that, given a number N, produces a list of the prime numbers from 1 to
N inclusive. It looks like this:
(2 = 0 +.= T o.| T) / T <- iN
where `o' is the APL null character, the assignment arrow is a single
character, and `i' represents the APL iota.
Here's a [9740]Perl program that prints primes:
perl -wle '(1 x $_) !~ /^(11+)\1+$/ && print while ++ $_'
In the Perl world this game is sometimes called Perl Golf because the
player with the fewest (key)strokes wins.
_________________________________________________________________
Node:ooblick, Next:[9741]op, Previous:[9742]one-liner wars, Up:[9743]=
O =
ooblick /oo'blik/ n.
[from the Dr. Seuss title "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. For optional
ingredients of this experience, see the "[9744]Ceremonial Chemicals"
section of Appendix B.
_________________________________________________________________
Node:op, Next:[9745]open, Previous:[9746]ooblick, Up:[9747]= O =
op /op/ n.
1. In England and Ireland, common verbal abbreviation for `operator',
as in system operator. Less common in the U.S., where [9748]sysop
seems to be preferred. 2. [IRC] Someone who is endowed with privileges
on [9749]IRC, not limited to a particular channel. These are generally
people who are in charge of the IRC server at their particular site.
Sometimes used interchangeably with [9750]CHOP. Compare [9751]sysop.
_________________________________________________________________
Node:open, Next:[9752]open source, Previous:[9753]op, Up:[9754]= O =
open n.
Abbreviation for `open (or left) parenthesis' -- used when necessary
to eliminate oral ambiguity. To read aloud the LISP form (DEFUN FOO
(X) (PLUS X 1)) one might say: "Open defun foo, open eks close, open,
plus eks one, close close."
_________________________________________________________________
Node:open source, Next:[9755]open switch, Previous:[9756]open,
Up:[9757]= O =
open source n.
[common; also adj. `open-source'] Term coined in March 1998 following
the Mozilla release to describe software distributed in source under
licenses guaranteeing anybody rights to freely use, modify, and
redistribute, the code. The intent was to be able to sell the hackers'
ways of doing software to industry and the mainstream by avoid the
negative connotations (to [9758]suits) of the term "[9759]free
software". For discussion of the followon tactics and their
consequences, see the [9760]Open Source Initiative site.
_________________________________________________________________
Node:open switch, Next:[9761]operating system, Previous:[9762]open
source, Up:[9763]= O =
open switch n.
[IBM: prob. from railroading] An unresolved question, issue, or
problem.
_________________________________________________________________
Node:operating system, Next:[9764]optical diff, Previous:[9765]open
switch, Up:[9766]= O =
operating system n.
[techspeak] (Often abbreviated `OS') The foundation software of a
machine; that which schedules tasks, allocates storage, and presents a
default interface to the user between applications. The facilities an
operating system provides and its general design philosophy exert an
extremely strong influence on programming style and on the technical
cultures that grow up around its host machines. Hacker folklore has
been shaped primarily by the [9767]Unix, [9768]ITS, [9769]TOPS-10,
[9770]TOPS-20/[9771]TWENEX, [9772]WAITS, [9773]CP/M, [9774]MS-DOS, and
[9775]Multics operating systems (most importantly by ITS and Unix).
_________________________________________________________________
Node:optical diff, Next:[9776]optical grep, Previous:[9777]operating
system, Up:[9778]= O =
optical diff n.
See [9779]vdiff.
_________________________________________________________________
Node:optical grep, Next:[9780]optimism, Previous:[9781]optical diff,
Up:[9782]= O =
optical grep n.
See [9783]vgrep.
_________________________________________________________________
Node:optimism, Next:[9784]Oracle the, Previous:[9785]optical grep,
Up:[9786]= O =
optimism n.
What a programmer is full of after fixing the last bug and before
discovering the next last bug. Fred Brooks's book "The Mythical
Man-Month" (See "Brooks's Law") contains the following paragraph that
describes this extremely well:
All programmers are optimists. Perhaps this modern sorcery
especially attracts those who believe in happy endings and fairy
godmothers. Perhaps the hundreds of nitty frustrations drive away
all but those who habitually focus on the end goal. Perhaps it is
merely that computers are young, programmers are younger, and the
young are always optimists. But however the selection process
works, the result is indisputable: "This time it will surely run,"
or "I just found the last bug.".
See also [9787]Lubarsky's Law of Cybernetic Entomology.
_________________________________________________________________
Node:Oracle the, Next:[9788]Orange Book, Previous:[9789]optimism,
Up:[9790]= O =
Oracle, the
The all-knowing, all-wise Internet Oracle rec.humor.oracle), or one of
the foreign language derivatives of same. Newbies frequently confuse
the Oracle with Oracle, a database vendor. As a result, the
unmoderated rec.humor.oracle.d is frequently crossposted to by the
clueless, looking for advice on SQL. As more than one person has said
in similar situations, "Don't people bother to look at the newsgroup
description line anymore?" (To which the standard response is, "Did
people ever read it in the first place?")
_________________________________________________________________
Node:Orange Book, Next:[9791]oriental food, Previous:[9792]Oracle the,
Up:[9793]= O =
Orange Book n.
The U.S. Government's standards document "Trusted Computer System
Evaluation Criteria, DOD standard 5200.28-STD, December, 1985" which
characterize secure computing architectures and defines levels A1
(most secure) through D (least). Modern Unixes are roughly C2. See
also [9794]crayola books, [9795]book titles.
_________________________________________________________________
Node:oriental food, Next:[9796]orphan, Previous:[9797]Orange Book,
Up:[9798]= O =
oriental food n.
Hackers display an intense tropism towards oriental cuisine,
especially Chinese, and especially of the spicier varieties such as
Szechuan and Hunan. This phenomenon (which has also been observed in
subcultures that overlap heavily with hackerdom, most notably
science-fiction fandom) has never been satisfactorily explained, but
is sufficiently intense that one can assume the target of a hackish
dinner expedition to be the best local Chinese place and be right at
least three times out of four. See also [9799]ravs, [9800]great-wall,
[9801]stir-fried random, [9802]laser chicken, [9803]Yu-Shiang Whole
Fish. Thai, Indian, Korean, and Vietnamese cuisines are also quite
popular.
_________________________________________________________________
Node:orphan, Next:[9804]orphaned i-node, Previous:[9805]oriental food,
Up:[9806]= O =
orphan n.
[Unix] A process whose parent has died; one inherited by init(1).
Compare [9807]zombie.
_________________________________________________________________
Node:orphaned i-node, Next:[9808]orthogonal, Previous:[9809]orphan,
Up:[9810]= O =
orphaned i-node /or'f*nd i:'nohd/ n.
[Unix] 1. [techspeak] A file that retains storage but no longer
appears in the directories of a filesystem. 2. By extension, a
pejorative for any person no longer serving a useful function within
some organization, esp. [9811]lion food without subordinates.
_________________________________________________________________
Node:orthogonal, Next:[9812]OS, Previous:[9813]orphaned i-node,
Up:[9814]= O =
orthogonal adj.
[from mathematics] Mutually independent; well separated; sometimes,
irrelevant to. Used in a generalization of its mathematical meaning to
describe sets of primitives or capabilities that, like a vector basis
in geometry, span the entire `capability space' of the system and are
in some sense non-overlapping or mutually independent. For example, in
architectures such as the PDP-11 or VAX where all or nearly all
registers can be used interchangeably in any role with respect to any
instruction, the register set is said to be orthogonal. Or, in logic,
the set of operators `not' and `or' is orthogonal, but the set `nand',
`or', and `not' is not (because any one of these can be expressed in
terms of the others). Also used in comments on human discourse: "This
may be orthogonal to the discussion, but...."
_________________________________________________________________
Node:OS, Next:[9815]OS/2, Previous:[9816]orthogonal, Up:[9817]= O =
OS /O-S/
1. [Operating System] n. An abbreviation heavily used in email,
occasionally in speech. 2. n. obs. On ITS, an output spy. See
"[9818]OS and JEDGAR" in Appendix A.
_________________________________________________________________
Node:OS/2, Next:[9819]OSS, Previous:[9820]OS, Up:[9821]= O =
OS/2 /O S too/ n.
The anointed successor to MS-DOS for Intel 286- and 386-based micros;
proof that IBM/Microsoft couldn't get it right the second time,
either. Often called `Half-an-OS'. Mentioning it is usually good for a
cheap laugh among hackers -- the design was so [9822]baroque, and the
implementation of 1.x so bad, that 3 years after introduction you
could still count the major [9823]apps shipping for it on the fingers
of two hands -- in unary. The 2.x versions are said to have improved
somewhat, and informed hackers now rate them superior to Microsoft
Windows (an endorsement which, however, could easily be construed as
damning with faint praise). See [9824]monstrosity, [9825]cretinous,
[9826]second-system effect.
_________________________________________________________________
Node:OSS, Next:[9827]OSU, Previous:[9828]OS/2, Up:[9829]= O =
OSS
Written-only acronym for "Open Source Software" (see [9830]open
source. This is a rather ugly [9831]TLA, and the principals in the
open-source movement don't use it, but it has (perhaps inevitably)
spread through the trade press like kudzu.
_________________________________________________________________
Node:OSU, Next:[9832]OTOH, Previous:[9833]OSS, Up:[9834]= O =
OSU /O-S-U/ n. obs.
[TMRC] Acronym for Officially Sanctioned User; a user who is
recognized as such by the computer authorities and allowed to use the
computer above the objections of the security monitor.
_________________________________________________________________
Node:OTOH, Next:[9835]out-of-band, Previous:[9836]OSU, Up:[9837]= O =
OTOH //
[Usenet; very common] On The Other Hand.
_________________________________________________________________
Node:out-of-band, Next:[9838]overclock, Previous:[9839]OTOH,
Up:[9840]= O =
out-of-band adj.
[from telecommunications and network theory] 1. In software, describes
values of a function which are not in its `natural' range of return
values, but are rather signals that some kind of exception has
occurred. Many C functions, for example, return a nonnegative integral
value, but indicate failure with an out-of-band return value of -1.
Compare [9841]hidden flag, [9842]green bytes, [9843]fence. 2. Also
sometimes used to describe what communications people call `shift
characters', such as the ESC that leads control sequences for many
terminals, or the level shift indicators in the old 5-bit Baudot
codes. 3. In personal communication, using methods other than email,
such as telephones or [9844]snail-mail.
_________________________________________________________________
Node:overclock, Next:[9845]overflow bit, Previous:[9846]out-of-band,
Up:[9847]= O =
overclock /oh'vr-klok'/ vt.
To operate a CPU or other digital logic device at a rate higher than
it was designed for, under the assumption that the manufacturer put
some [9848]slop into the specification to account for manufacturing
tolerances. Overclocking something can result in intermittent
[9849]crashes, and can even burn things out, since power dissipation
is directly proportional to [9850]clock frequency. People who make a
hobby of this are sometimes called "overclockers"; they are thrilled
that they can run their 450MHz CPU at 500MHz, even though they can
only tell the difference by running a [9851]benchmark program.
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Node:overflow bit, Next:[9852]overflow pdl, Previous:[9853]overclock,
Up:[9854]= O =
overflow bit n.
1. [techspeak] A [9855]flag on some processors indicating an attempt
to calculate a result too large for a register to hold. 2. More
generally, an indication of any kind of capacity overload condition.
"Well, the [9856]Ada description was [9857]baroque all right, but I
could hack it OK until they got to the exception handling ... that set
my overflow bit." 3. The hypothetical bit that will be set if a hacker
doesn't get to make a trip to the Room of Porcelain Fixtures: "I'd
better process an internal interrupt before the overflow bit gets
set."
_________________________________________________________________
Node:overflow pdl, Next:[9858]overrun, Previous:[9859]overflow bit,
Up:[9860]= O =
overflow pdl n.
[MIT] The place where you put things when your [9861]PDL is full. If
you don't have one and too many things get pushed, you forget
something. The overflow pdl for a person's memory might be a memo pad.
This usage inspired the following doggerel:
Hey, diddle, diddle
The overflow pdl
To get a little more stack;
If that's not enough
Then you lose it all,
And have to pop all the way back.
-The Great Quux
The term `pdl' (see [9862]PDL) seems to be primarily an MITism;
outside MIT this term is replaced by `overflow [9863]stack' (but that
wouldn't rhyme with `diddle').
_________________________________________________________________
Node:overrun, Next:[9864]overrun screw, Previous:[9865]overflow pdl,
Up:[9866]= O =
overrun n.
1. [techspeak] Term for a frequent consequence of data arriving faster
than it can be consumed, esp. in serial line communications. For
example, at 9600 baud there is almost exactly one character per
millisecond, so if a [9867]silo can hold only two characters and the
machine takes longer than 2 msec to get to service the interrupt, at
least one character will be lost. 2. Also applied to non-serial-I/O
communications. "I forgot to pay my electric bill due to mail
overrun." "Sorry, I got four phone calls in 3 minutes last night and
lost your message to overrun." When [9868]thrashing at tasks, the next
person to make a request might be told "Overrun!" Compare
[9869]firehose syndrome. 3. More loosely, may refer to a [9870]buffer
overflow not necessarily related to processing time (as in
[9871]overrun screw).
_________________________________________________________________
Node:overrun screw, Next:[9872]P-mail, Previous:[9873]overrun,
Up:[9874]= O =
overrun screw n.
[C programming] A variety of [9875]fandango on core produced by
scribbling past the end of an array (C implementations typically have
no checks for this error). This is relatively benign and easy to spot
if the array is static; if it is auto, the result may be to
[9876]smash the stack -- often resulting in [9877]heisenbugs of the
most diabolical subtlety. The term `overrun screw' is used esp. of
scribbles beyond the end of arrays allocated with malloc(3); this
typically trashes the allocation header for the next block in the
[9878]arena, producing massive lossage within malloc and often a core
dump on the next operation to use stdio(3) or malloc(3) itself. See
[9879]spam, [9880]overrun; see also [9881]memory leak, [9882]memory
smash, [9883]aliasing bug, [9884]precedence lossage, [9885]fandango on
core, [9886]secondary damage.
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Node:= P =, Next:[9887]= Q =, Previous:[9888]= O =, Up:[9889]The
Jargon Lexicon
= P =
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