The Hacker's Dictionary, - [best reads of all time .txt] 📗

other; to swap places. If you point to two people sitting down and say "Exch!", you are asking them to trade places. EXCH, meaning EXCHange, was originally the name of a PDP-10 instruction that exchanged the contents of a register and a memory location.

Many newer hackers tend to be thinking instead of the {PostScript}

exchange operator (which is usually written in lowercase).

:excl: /eks'kl/ n. Abbreviation for `exclamation point'. See {bang}, {shriek}, {{ASCII}}.

:EXE: /eks'ee/ or /eek'see/ or /E-X-E/ n. An executable binary file. Some operating systems (notably MS-DOS, VMS, and TWENEX) use the extension .EXE to mark such files. This usage is also occasionally found among UNIX programmers even though UNIX

executables don't have any required suffix.

:exec: /eg-zek'/ vt.,n. 1. [UNIX: from execute'] Synonym for {chain}, derives from theexec(2)' call. 2. [from `executive'] obs. The command interpreter for an {OS} (see {shell}); term esp. used around mainframes, and prob.

derived from UNIVAC's archaic EXEC 2 and EXEC 8 operating systems.

At IBM and VM/CMS shops, the equivalent of a shell command file (among VM/CMS users).

The mainstream exec' as an abbreviation for (human) executive is *not* used. To a hacker, anexec' is a always a program, never a person.

:exercise, left as an: [from technical books] Used to complete a proof when one doesn't mind a {handwave}, or to avoid one entirely. The complete phrase is: "The proof (or the rest) is left as an exercise for the reader." This comment has

occasionally been attached to unsolved research problems by authors possessed of either an evil sense of humor or a vast faith in the capabilities of their audiences.

:eyeball search: n. To look for something in a mass of code or data with one's own native optical sensors, as opposed to using some sort of pattern matching software like {grep} or any other automated search tool. Also called a {vgrep}; compare {vdiff}, {desk check}.

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:fab: /fab/ [from `fabricate'] v. 1. To produce chips from a design that may have been created by someone at another company.

Fabbing chips based on the designs of others is the activity of a {silicon foundry}. To a hacker, fab' is practically never short forfabulous'. 2. fab line': the production system (lithography, diffusion, etching, etc.) for chips at a chip manufacturer. Differentfab lines' are run with different process parameters, die sizes, or technologies, or simply to provide more manufacturing volume.

:face time: n. Time spent interacting with somebody face-to-face (as opposed to via electronic links). "Oh, yeah, I spent some face time with him at the last Usenix."

:factor: n. See {coefficient of X}.

:fall over: [IBM] vi. Yet another synonym for {crash} or {lose}.

`Fall over hard' equates to {crash and burn}.

:fall through: v. (n. fallthrough', var.fall-through') 1. To exit a loop by exhaustion, i.e., by having fulfilled its exit condition rather than via a break or exception condition that exits from the middle of it. This usage appears to be really old, dating from the 1940s and 1950s. 2. To fail a test that would have passed control to a subroutine or some other distant portion of code. 3. In C, fall-through' occurs when the flow of execution in a switch statement reaches acase' label other than by jumping there from the switch header, passing a point where one would normally expect to find a `break'. A trivial example: switch (color)

{ case GREEN: do_green(); break; case PINK: do_pink(); /* FALL THROUGH */ case RED: do_red(); break; default: do_blue(); break; }

The variant spelling `/ FALL THRU /' is also common.

The effect of this code is to do_green()' when color isGREEN', do_red()' when color isRED', do_blue()' on any other color other thanPINK', and (and this is the important part) `do_pink()' and then

do_red()' when color isPINK'. Fall-through is {considered harmful} by some, though there are contexts (such as the coding of state machines) in which it is natural; it is generally considered good practice to include a comment highlighting the fall-through where one would normally expect a break.

:fandango on core: [UNIX/C hackers, from the Mexican dance] n.

In C, a wild pointer that runs out of bounds, causing a {core dump}, or corrupts the malloc(3)' {arena} in such a way as to cause mysterious failures later on, is sometimes said to havedone a fandango on core'. On low-end personal machines without an MMU, this can corrupt the OS itself, causing massive lossage.

Other frenetic dances such as the rhumba, cha-cha, or watusi, may be substituted. See {aliasing bug}, {precedence lossage}, {smash the stack}, {memory leak}, {memory smash}, {overrun screw}, {core}.

:FAQ list: /F-A-Q list/ or /fak list/ [USENET] n. A compendium of accumulated lore, posted periodically to high-volume newsgroups in an attempt to forestall Frequently Asked Questions. This lexicon itself serves as a good example of a collection of one kind of lore, although it is far too big for a regular posting.

Examples: "What is the proper type of NULL?" and "What's that funny name for the `#' character?" are both Frequently Asked Questions. Several extant FAQ lists do (or should) make reference to the Jargon File (the on-line version of this lexicon).

:FAQL: /fa'kl/ n. Syn. {FAQ list}.

:farming: [Adelaide University, Australia] n. What the heads of a disk drive are said to do when they plow little furrows in the magnetic media. Associated with a {crash}. Typically used as follows: "Oh no, the machine has just crashed; I hope the hard drive hasn't gone {farming} again."

:fascist: adj. 1. Said of a computer system with excessive or annoying security barriers, usage limits, or access policies. The implication is that said policies are preventing hackers from getting interesting work done. The variant fascistic' seems to have been preferred at MIT, poss. by analogy withtouristic' (see {tourist}). 2. In the design of languages and other software tools, `the fascist alternative' is the most restrictive and structured way of capturing a particular function; the implication is that this may be desirable in order to simplify the implementation or provide tighter error checking. Compare {bondage-and-discipline language}, but that term is global rather than local.

:fat electrons: n. Old-time hacker David Cargill's theory on the causation of computer glitches. Your typical electric utility draws its line current out of the big generators with a pair of coil taps located near the top of the dynamo. When the normal tap brushes get dirty, they take them off line to clean up, and use special auxiliary taps on the bottom of the coil. Now, this is a problem, because when they do that they get not ordinary or `thin' electrons, but the fat'n'sloppy electrons that are heavier and so settle to the bottom of the generator. These flow down ordinary wires just fine, but when they have to turn a sharp corner (as in an integrated-circuit via) they're apt to get stuck.

This is what causes computer glitches. [Fascinating. Obviously, fat electrons must gain mass by {bogon} absorption --- ESR]

Compare {bogon}, {magic smoke}.

:faulty: adj. Non-functional; buggy. Same denotation as {bletcherous}, {losing}, q.v., but the connotation is much milder.

:fd leak: /F-D leek/ n. A kind of programming bug analogous to a {core leak}, in which a program fails to close file descriptors (`fd's) after file operations are completed, and thus eventually runs out of them. See {leak}.

:fear and loathing: [from Hunter Thompson] n. A state inspired by the prospect of dealing with certain real-world systems and standards that are totally {brain-damaged} but ubiquitous --- Intel 8086s, or {COBOL}, or {{EBCDIC}}, or any {IBM} machine except the Rios (a.k.a. the RS/6000). "Ack! They want PCs to be able to talk to the AI machine. Fear and loathing time!"

:feature: n. 1. A good property or behavior (as of a program).

Whether it was intended or not is immaterial. 2. An intended property or behavior (as of a program). Whether it is good or not is immaterial (but if bad, it is also a {misfeature}). 3. A surprising property or behavior; in particular, one that is purposely inconsistent because it works better that way --- such an inconsistency is therefore a {feature} and not a {bug}. This kind of feature is sometimes called a {miswart}; see that entry for a classic example. 4. A property or behavior that is gratuitous or unnecessary, though perhaps also impressive or cute.

For example, one feature of Common LISP's `format' function is the ability to print numbers in two different Roman-numeral formats (see {bells, whistles, and gongs}). 5. A property or behavior that was put in to help someone else but that happens to be in your way. 6. A bug that has been documented. To call something a feature sometimes means the author of the program did not consider the particular case, and that the program responded in a way that was unexpected but not strictly incorrect. A standard joke is that a bug can be turned into a {feature} simply by documenting it (then theoretically no one can complain about it because it's in the manual), or even by simply declaring it to be good. "That's not a bug, that's a feature!" is a common catchphrase. See also {feetch feetch}, {creeping featurism}, {wart}, {green lightning}.

The relationship among bugs, features, misfeatures, warts, and