The Jargon File by Eric S. Raymond (sites to read books for free .TXT) 📖

program in an

unusual way notices that it never should have worked, at which point

the program promptly stops working for everybody until fixed. Though

(like [11825]bit rot) this sounds impossible, it happens; some

programs have harbored latent schroedinbugs for years. Compare

[11826]heisenbug, [11827]Bohr bug, [11828]mandelbug.

Node:science-fiction fandom, Next:[11829]scram switch,

Previous:[11830]schroedinbug, Up:[11831]= S =

science-fiction fandom n.

Another voluntary subculture having a very heavy overlap with

hackerdom; most hackers read SF and/or fantasy fiction avidly, and

many go to `cons' (SF conventions) or are involved in fandom-connected

activities such as the Society for Creative Anachronism. Some hacker

jargon originated in SF fandom; see [11832]defenestration,

[11833]great-wall, [11834]cyberpunk, [11835]h, [11836]ha ha only

serious, [11837]IMHO, [11838]mundane, [11839]neep-neep, [11840]Real

Soon Now. Additionally, the jargon terms [11841]cowboy,

[11842]cyberspace, [11843]de-rezz, [11844]go flatline, [11845]ice,

[11846]phage, [11847]virus, [11848]wetware, [11849]wirehead, and

[11850]worm originated in SF stories.

Node:scram switch, Next:[11851]scratch,

Previous:[11852]science-fiction fandom, Up:[11853]= S =

scram switch n.

[from the nuclear power industry] An emergency-power-off switch (see

[11854]Big Red Switch), esp. one positioned to be easily hit by

evacuating personnel. In general, this is not something you

[11855]frob lightly; these often initiate expensive events (such as

Halon dumps) and are installed in a [11856]dinosaur pen for use in

case of electrical fire or in case some luckless [11857]field servoid

should put 120 volts across himself while [11858]Easter egging. (See

also [11859]molly-guard, [11860]TMRC.)

A correspondent reports a legend that "Scram" is an acronym for "Start

Cutting Right Away, Man" (another less plausible variant of this

legend refers to "Safety Control Rod Axe Man"; these are almost

certainly both [11861]backronyms). The story goes that in the earliest

nuclear power experiments the engineers recognized the possibility

that the reactor wouldn't behave exactly as predicted by their

mathematical models. Accordingly, they made sure that they had

mechanisms in place that would rapidly drop the control rods back into

the reactor. One mechanism took the form of `scram technicians'. These

individuals stood next to the ropes or cables that raised and lowered

the control rods. Equipped with axes or cable-cutters, these

technicians stood ready for the (literal) `scram' command. If

necessary, they would cut the cables, and gravity would expeditiously

return the control rods to the reactor, thereby averting yet another

kind of [11862]core dump.

Modern reactor control rods are held in place with claw-like devices,

held closed by current. SCRAM switches are circuit breakers that

immediately open the circuit to the rod arms, resulting in the rapid

insertion and subsequent bottoming of the control rods.

Node:scratch, Next:[11863]scratch monkey, Previous:[11864]scram

switch, Up:[11865]= S =

scratch

[from `scratchpad'] adj. Describes a data structure or recording

medium attached to a machine for testing or temporary-use purposes;

one that can be [11866]scribbled on without loss. Usually in the

combining forms scratch memory',scratch register', `scratch disk',

scratch tape',scratch volume'. See also [11867]scratch monkey. 2.

[primarily IBM] vt. To delete (as in a file).

Node:scratch monkey, Next:[11868]scream and die,

Previous:[11869]scratch, Up:[11870]= S =

scratch monkey n.

As in "Before testing or reconfiguring, always mount a [11871]scratch

monkey", a proverb used to advise caution when dealing with

irreplaceable data or devices. Used to refer to any scratch volume

hooked to a computer during any risky operation as a replacement for

some precious resource or data that might otherwise get trashed.

This term preserves the memory of Mabel, the Swimming Wonder Monkey,

star of a biological research program at the University of Toronto.

Mabel was not (so the legend goes) your ordinary monkey; the

university had spent years teaching her how to swim, breathing through

a regulator, in order to study the effects of different gas mixtures

on her physiology. Mabel suffered an untimely demise one day when a

[11872]DEC [11873]field circus engineer troubleshooting a crash on the

program's VAX inadvertently interfered with some custom hardware that

was wired to Mabel.

It is reported that, after calming down an understandably irate

customer sufficiently to ascertain the facts of the matter, a DEC

troubleshooter called up the [11874]field circus manager responsible

and asked him sweetly, "Can you swim?"

Not all the consequences to humans were so amusing; the sysop of the

machine in question was nearly thrown in jail at the behest of certain

clueless [11875]droids at the local `humane' society. The moral is

clear: When in doubt, always mount a scratch monkey.

[The actual incident occured in 1979 or 1980. There is a version of

this story, complete with reported dialogue between one of the project

people and DEC field service, that has been circulating on Internet

since 1986. It is hilarious and mythic, but gets some facts wrong. For

example, it reports the machine as a PDP-11 and alleges that Mabel's

demise occurred when DEC [11876]PMed the machine. Earlier versions of

this entry were based on that story; this one has been corrected from

an interview with the hapless sysop. --ESR]

Node:scream and die, Next:[11877]screaming tty,

Previous:[11878]scratch monkey, Up:[11879]= S =

scream and die v.

Syn. [11880]cough and die, but connotes that an error message was

printed or displayed before the program crashed.

Node:screaming tty, Next:[11881]screen, Previous:[11882]scream and

die, Up:[11883]= S =

screaming tty n.

[Unix] A terminal line which spews an infinite number of random

characters at the operating system. This can happen if the terminal is

either disconnected or connected to a powered-off terminal but still

enabled for login; misconfiguration, misimplementation, or simple bad

luck can start such a terminal screaming. A screaming tty or two can

seriously degrade the performance of a vanilla Unix system; the

arriving "characters" are treated as userid/password pairs and tested

as such. The Unix password encryption algorithm is designed to be

computationally intensive in order to foil brute-force crack attacks,

so although none of the logins succeeds; the overhead of rejecting

them all can be substantial.

Node:screen, Next:[11884]screen name, Previous:[11885]screaming tty,

Up:[11886]= S =

screen n.

[Atari ST [11887]demoscene] One [11888]demoeffect or one screenful of

them. Probably comes from old Sierra-style adventures or shoot-em-ups

where one travels from one place to another one screenful at a time.

Node:screen name, Next:[11889]screw, Previous:[11890]screen,

Up:[11891]= S =

screen name n.

A [11892]handle sense 1. This term has been common among users of IRC,

MUDs, and commercial on-line services since the mid-1990s. Hackers

recognize the term but don't generally use it.

Node:screw, Next:[11893]screwage, Previous:[11894]screen name,

Up:[11895]= S =

screw n.

[MIT] A [11896]lose, usually in software. Especially used for

user-visible misbehavior caused by a bug or misfeature. This use has

become quite widespread outside MIT.

Node:screwage, Next:[11897]scribble, Previous:[11898]screw,

Up:[11899]= S =

screwage /skroo'*j/ n.

Like [11900]lossage but connotes that the failure is due to a

designed-in misfeature rather than a simple inadequacy or a mere bug.

Node:scribble, Next:[11901]script kiddies, Previous:[11902]screwage,

Up:[11903]= S =

scribble n.

To modify a data structure in a random and unintentionally destructive

way. "Bletch! Somebody's disk-compactor program went berserk and

scribbled on the i-node table." "It was working fine until one of the

allocation routines scribbled on low core." Synonymous with

[11904]trash; compare [11905]mung, which conveys a bit more intention,

and [11906]mangle, which is more violent and final.

Node:script kiddies, Next:[11907]scrog, Previous:[11908]scribble,

Up:[11909]= S =

script kiddies pl.n.

The lowest form of [11910]cracker; script kiddies do mischief with

scripts and programs written by others, often without understanding

the [11911]exploit. 2. People who cannot program, but who create tacky

HTML pages by copying JavaScript routines from other tacky HTML pages.

More generally, a script kiddie writes (or more likely cuts and

pastes) code without either having or desiring to have a mental model

of what the code does; someone who thinks of code as magical

incantations and asks only "what do I need to type to make this

happen?"

Node:scrog, Next:[11912]scrool, Previous:[11913]script kiddies,

Up:[11914]= S =

scrog /skrog/ vt.

[Bell Labs] To damage, trash, or corrupt a data structure. "The list

header got scrogged." Also reported as `skrog', and ascribed to the

comic strip "The Wizard of Id". Compare [11915]scag; possibly the two

are related. Equivalent to [11916]scribble or [11917]mangle.

Node:scrool, Next:[11918]scrozzle, Previous:[11919]scrog, Up:[11920]=

S =

scrool /skrool/ n.

[from the pioneering Roundtable chat system in Houston ca. 1984; prob.

originated as a typo for `scroll'] The log of old messages, available

for later perusal or to help one get back in synch with the

conversation. It was originally called the `scrool monster', because

an early version of the roundtable software had a bug where it would

dump all 8K of scrool on a user's terminal.

Node:scrozzle, Next:[11921]scruffies, Previous:[11922]scrool,

Up:[11923]= S =

scrozzle /skroz'l/ vt.

Used when a self-modifying code segment runs incorrectly and corrupts

the running program or vital data. "The damn compiler scrozzled itself

again!"

Node:scruffies, Next:[11924]SCSI, Previous:[11925]scrozzle,

Up:[11926]= S =

scruffies n.

See [11927]neats vs. scruffies.

Node:SCSI, Next:[11928]ScumOS, Previous:[11929]scruffies, Up:[11930]=

S =

SCSI n.

[Small Computer System Interface] A bus-independent standard for

system-level interfacing between a computer and intelligent devices.

Typically annotated in literature with sexy' (/sek'see/),sissy'

(/sis'ee/), and `scuzzy' (/skuh'zee/) as pronunciation guides -- the

last being the overwhelmingly predominant form, much to the dismay of

the designers and their marketing people. One can usually assume that

a person who pronounces it /S-C-S-I/ is clueless.

Node:ScumOS, Next:[11931]search-and-destroy mode,

Previous:[11932]SCSI, Up:[11933]= S =

ScumOS /skuhm'os/ or /skuhm'O-S/ n.

Unflattering hackerism for SunOS, the BSD Unix variant supported on

Sun Microsystems's Unix workstations (see also [11934]sun-stools), and

compare [11935]AIDX, [11936]Macintrash, [11937]Nominal Semidestructor,

[11938]HP-SUX. Despite what this term might suggest, Sun was founded

by hackers and still enjoys excellent relations with hackerdom; usage

is more often in exasperation than outright loathing.

Node:search-and-destroy mode, Next:[11939]second-system effect,

Previous:[11940]ScumOS, Up:[11941]= S =

search-and-destroy mode n.

Hackerism for a noninteractive search-and-replace facility in an

editor, so called because an incautiously chosen match pattern can

cause [11942]infinite damage.

Node:second-system effect, Next:[11943]secondary damage,

Previous:[11944]search-and-destroy mode, Up:[11945]= S =

second-system effect n.

(sometimes, more euphoniously, `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 [11946]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

[11947]Brooks's Law, [11948]creeping elegance, [11949]creeping

featurism. See also [11950]Multics, [11951]OS/2, [11952]X,

[11953]software bloat.

This version of the jargon lexicon has been described (with altogether

too much truth for comfort) as an example of second-system effect run

amok on jargon-1....

Node:secondary damage, Next:[11954]security through obscurity,

Previous:[11955]second-system effect, Up:[11956]= S =

secondary damage n.

When a fatal error occurs (esp. a [11957]segfault) the immediate cause

may be that a pointer has been trashed due to a previous

[11958]fandango on core. However, this fandango may have been due to

an earlier fandango, so no amount of analysis will reveal (directly)

how the damage occurred. "The data structure was clobbered, but it was

secondary damage."

By extension, the corruption resulting from N cascaded fandangoes on

core is `Nth-level damage'. There is at least one case on record in

which 17 hours of [11959]grovelling with adb actually dug up the

underlying bug behind an instance of seventh-level damage! The hacker

who accomplished this near-superhuman feat was presented with an award

by his fellows.

Node:security through obscurity, Next:[11960]SED,

Previous:[11961]secondary damage, Up:[11962]= S =

security through obscurity

(alt. `security by obscurity') A term applied by hackers to most OS

vendors' favorite way of coping with security holes -- namely,

ignoring them, documenting neither any known holes nor the underlying

security algorithms, trusting that nobody will find out about them and

that people who do find out about them won't exploit them. This

"strategy" never works for long and occasionally sets the world up for

debacles like the [11963]RTM worm of 1988 (see [11964]Great Worm), but

once the brief moments of panic created by such events subside most