Part 5

:avatar: [CMU, Tektronix] n. Syn. {root}, {superuser}. There are quite a few UNIX machines on which the name of the superuser account is `avatar' rather than `root'. This quirk was originated by a CMU hacker who disliked the term `superuser', and was propagated through an ex-CMU hacker at Tektronix.

:awk: 1. n. [UNIX techspeak] An interpreted language for massaging text data developed by Alfred Aho, Peter Weinberger, and Brian Kernighan (the name is from their initials). It is characterized by C-like syntax, a declaration-free approach to variable typing and declarations, associative arrays, and field-oriented text processing. See also {Perl}. 2. n. Editing term for an expression awkward to manipulate through normal {regexp} facilities (for example, one containing a {newline}). 3. vt. To process data using `awk(1)'.

= B = =====

:back door: n. A hole in the security of a system deliberately left in place by designers or maintainers. The motivation for this is not always sinister; some operating systems, for example, come out of the box with privileged accounts intended for use by field service technicians or the vendor's maintenance programmers.

Historically, back doors have often lurked in systems longer than anyone expected or planned, and a few have become widely known. The infamous {RTM} worm of late 1988, for example, used a back door in the {BSD} UNIX `sendmail(8)' utility.

Ken Thompson's 1983 Turing Award lecture to the ACM revealed the existence of a back door in early UNIX versions that may have qualified as the most fiendishly clever security hack of all time. The C compiler contained code that would recognize when the `login' command was being recompiled and insert some code recognizing a password chosen by Thompson, giving him entry to the system whether or not an account had been created for him.

Normally such a back door could be removed by removing it from the source code for the compiler and recompiling the compiler. But to recompile the compiler, you have to *use* the compiler --- so Thompson also arranged that the compiler would *recognize when it was compiling a version of itself*, and insert into the recompiled compiler the code to insert into the recompiled `login' the code to allow Thompson entry --- and, of course, the code to recognize itself and do the whole thing again the next time around! And having done this once, he was then able to recompile the compiler from the original sources, leaving his back door in place and active but with no trace in the sources.

The talk that revealed this truly moby hack was published as "Reflections on Trusting Trust", `Communications of the ACM 27', 8 (August 1984), pp. 761--763.

Syn. {trap door}; may also be called a `wormhole'. See also {iron box}, {cracker}, {worm}, {logic bomb}.

:backbone cabal: n. A group of large-site administrators who pushed through the {Great Renaming} and reined in the chaos of {USENET} during most of the 1980s. The cabal {mailing list} disbanded in late 1988 after a bitter internal catfight, but the net hardly noticed.

:backbone site: n. A key USENET and email site; one that processes a large amount of third-party traffic, especially if it is the home site of any of the regional coordinators for the USENET maps. Notable backbone sites as of early 1991 include uunet and the mail machines at Rutgers University, UC Berkeley, DEC's Western Research Laboratories, Ohio State University, and the University of Texas. Compare {rib site}, {leaf site}.

:backgammon:: See {bignum}, {moby}, and {pseudoprime}.

:background: n.,adj.,vt. To do a task `in background' is to do it whenever {foreground} matters are not claiming your undivided attention, and `to background' something means to relegate it to a lower priority. "For now, we'll just print a list of nodes and links; I'm working on the graph-printing problem in background." Note that this implies ongoing activity but at a reduced level or in spare time, in contrast to mainstream `back burner' (which connotes benign neglect until some future resumption of activity). Some people prefer to use the term for processing that they have queued up for their unconscious minds (a tack that one can often fruitfully take upon encountering an obstacle in creative work). Compare {amp off}, {slopsucker}.

Technically, a task running in background is detached from the terminal where it was started (and often running at a lower priority); oppose {foreground}. Nowadays this term is primarily associated with {{UNIX}}, but it appears to have been first used in this sense on OS/360.

:backspace and overstrike: interj. Whoa! Back up. Used to suggest that someone just said or did something wrong. Common among APL programmers.

:backward combatability: /bak'w*rd k*m-bat'*-bil'*-tee/ [from `backward compatibility'] n. A property of hardware or software revisions in which previous protocols, formats, and layouts are discarded in favor of `new and improved' protocols, formats, and layouts. Occurs usually when making the transition between major releases. When the change is so drastic that the old formats are not retained in the new version, it is said to be `backward combatable'. See {flag day}.

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

:Bad Thing: [from the 1930 Sellar & Yeatman parody `1066 And All That'] n. 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. This has apparently created a mainstream idiom on the British side of the pond.

:bag on the side: n. An extension to an established hack that is supposed to add some functionality to the original. Usually derogatory, implying that the original was being overextended and should have been thrown away, and the new product is ugly, inelegant, or bloated. Also v. phrase, `to hang a bag on the side [of]'. "C++? That's just a bag on the side of C ...." "They want me to hang a bag on the side of the accounting system."

:bagbiter: /bag'bi:t-*r/ n. 1. Something, such as a program or a computer, that fails to work, or works in a remarkably clumsy manner. "This text editor won't let me make a file with a line longer than 80 characters! What a bagbiter!" 2. A person who has caused you some trouble, inadvertently or otherwise, typically by failing to program the computer properly. Synonyms: {loser}, {cretin}, {chomper}. 3. adj. `bagbiting' Having the quality of a bagbiter. "This bagbiting system won't let me compute the factorial of a negative number." Compare {losing}, {cretinous}, {bletcherous}, `barfucious' (under {barfulous}) and `chomping' (under {chomp}). 4. `bite the bag' vi. To fail in some manner. "The computer keeps crashing every 5 minutes." "Yes, the disk controller is really biting the bag." The original loading of these terms was almost undoubtedly obscene, possibly referring to the scrotum, but in their current usage they have become almost completely sanitized.

A program called Lexiphage on the old MIT AI PDP-10 would draw on a selected victim's bitmapped terminal the words "THE BAG" in ornate letters, and then a pair of jaws biting pieces of it off. This is the first and to date only known example of a program *intended* to be a bagbiter.

:bamf: /bamf/ 1. [from old X-Men comics] interj. Notional sound made by a person or object teleporting in or out of the hearer's vicinity. Often used in {virtual reality} (esp. {MUD}) electronic {fora} when a character wishes to make a dramatic entrance or exit. 2. The sound of magical transformation, used in virtual reality {fora} like sense 1. 3. [from `Don Washington's Survival Guide'] n. Acronym for `Bad-Ass Mother Fucker', used to refer to one of the handful of nastiest monsters on an LPMUD or other similar MUD.

:banana label: n. The labels often used on the sides of {macrotape} reels, so called because they are shaped roughly like blunt-ended bananas. This term, like macrotapes themselves, is still current but visibly headed for obsolescence.

:banana problem: n. [from the story of the little girl who said "I know how to spell `banana', but I don't know when to stop"]. Not knowing where or when to bring a production to a close (compare {fencepost error}). One may say `there is a banana problem' of an algorithm with poorly defined or incorrect termination conditions, or in discussing the evolution of a design that may be succumbing to featuritis (see also {creeping elegance}, {creeping featuritis}). See item 176 under {HAKMEM}, which describes a banana problem in a {Dissociated Press} implementation. Also, see {one-banana problem} for a superficially similar but unrelated usage.

:bandwidth: n. 1. Used by hackers in a generalization of its technical meaning as the volume of information per unit time that a computer, person, or transmission medium can handle. "Those are amazing graphics, but I missed some of the detail --- not enough bandwidth, I guess." Compare {low-bandwidth}. 2. Attention span. 3. On {USENET}, a measure of network capacity that is often wasted by people complaining about how items posted by others are a waste of bandwidth.

:bang: 1. n. Common spoken name for `!' (ASCII 0100001), especially when used in pronouncing a {bang path} in spoken hackish. In {elder days} this was considered a CMUish usage, with MIT and Stanford hackers preferring {excl} or {shriek}; but the spread of UNIX has carried `bang' with it (esp. via the term {bang path}) and it is now certainly the most common spoken name for `!'. Note that it is used exclusively for non-emphatic written `!'; one would not say "Congratulations bang" (except possibly for humorous purposes), but if one wanted to specify the exact characters `foo!' one would speak "Eff oh oh bang". See {shriek}, {{ASCII}}. 2. interj. An exclamation signifying roughly "I have achieved enlightenment!", or "The dynamite has cleared out my brain!" Often used to acknowledge that one has perpetrated a {thinko} immediately after one has been called on it.

:bang on: vt. To stress-test a piece of hardware or software: "I banged on the new version of the simulator all day yesterday and it didn't crash once. I guess it is ready for release." The term {pound on} is synonymous.

:bang path: n. An old-style UUCP electronic-mail address specifying hops to get from some assumed-reachable location to the addressee, so called because each {hop} is signified by a {bang} sign. Thus, for example, the path ...!bigsite!foovax!barbox!me directs people to route their mail to machine bigsite (presumably a well-known location accessible to everybody) and from there through the machine foovax to the account of user me on barbox.

In the bad old days of not so long ago, before autorouting mailers became commonplace, people often published compound bang addresses using the { } convention (see {glob}) to give paths from *several* big machines, in the hopes that one's correspondent might be able to get mail to one of them reliably (example: ...!{seismo, ut-sally, ihnp4}!rice!beta!gamma!me). Bang paths of 8 to 10 hops were not uncommon in 1981. Late-night dial-up UUCP links would cause week-long transmission times. Bang paths were often selected by both transmission time and reliability, as messages would often get lost. See {{Internet address}}, {network, the}, and {sitename}.

:banner: n. 1. The title page added to printouts by most print spoolers (see {spool}). Typically includes user or account ID information in very large character-graphics capitals. Also called a `burst page', because it indicates where to burst (tear apart) fanfold paper to separate one user's printout from the next. 2. A similar printout generated (typically on multiple pages of fan-fold paper) from user-specified text, e.g., by a program such as UNIX's `banner({1,6})'. 3. On interactive software, a first screen containing a logo and/or author credits and/or a copyright notice.

:bar: /bar/ n. 1. The second {metasyntactic variable}, after {foo} and before {baz}. "Suppose we have two functions: FOO and BAR. FOO calls BAR...." 2. Often appended to {foo} to produce {foobar}.

:bare metal: n. 1. New computer hardware, unadorned with such snares and delusions as an {operating system}, an {HLL}, or even assembler. Commonly used in the phrase `programming on the bare metal', which refers to the arduous work of {bit bashing} needed to create these basic tools for a new machine. Real bare-metal programming involves things like building boot proms and BIOS chips, implementing basic monitors used to test device drivers, and writing the assemblers that will be used to write the compiler back ends that will give the new machine a real development environment. 2. `Programming on the bare metal' is also used to describe a style of {hand-hacking} that relies on bit-level peculiarities of a particular hardware design, esp. tricks for speed and space optimization that rely on crocks such as overlapping instructions (or, as in the famous case described in {The Story of Mel, a Real Programmer} (in {appendix A}), interleaving of opcodes on a magnetic drum to minimize fetch delays due to the device's rotational latency). This sort of thing has become less common as the relative costs of programming time and machine resources have changed, but is still found in heavily constrained environments such as industrial embedded systems. See {real programmer}.

In the world of personal computing, bare metal programming (especially in sense 1 but sometimes also in sense 2) is often considered a {Good Thing}, or at least a necessary evil (because these machines have often been sufficiently slow and poorly designed to make it necessary; see {ill-behaved}). There, the term usually refers to bypassing the BIOS or OS interface and writing the application to directly access device registers and machine addresses. "To get 19.2 kilobaud on the serial port, you need to get down to the bare metal." People who can do this sort of thing are held in high regard.

:barf: /barf/ [from mainstream slang meaning `vomit'] 1. interj. Term of disgust. This is the closest hackish equivalent of the Val\-speak "gag me with a spoon". (Like, euwww!) See {bletch}. 2. vi. To say "Barf!" or emit some similar expression of disgust. "I showed him my latest hack and he barfed" means only that he complained about it, not that he literally vomited. 3. vi. To fail to work because of unacceptable input. May mean to give an error message. Examples: "The division operation barfs if you try to divide by 0." (That is, the division operation checks for an attempt to divide by zero, and if one is encountered it causes the operation to fail in some unspecified, but generally obvious, manner.) "The text editor barfs if you try to read in a new file before writing out the old one." See {choke}, {gag}. In Commonwealth hackish, `barf' is generally replaced by `puke' or `vom'. {barf} is sometimes also used as a {metasyntactic variable}, like {foo} or {bar}.

:barfmail: n. Multiple {bounce message}s accumulating to the level of serious annoyance, or worse. The sort of thing that happens when an inter-network mail gateway goes down or wonky.

:barfulation: /bar`fyoo-lay'sh*n/ interj. Variation of {barf} used around the Stanford area. An exclamation, expressing disgust. On seeing some particularly bad code one might exclaim, "Barfulation! Who wrote this, Quux?"

:barfulous: /bar'fyoo-l*s/ adj. (alt. `barfucious', /bar-fyoo-sh*s/) Said of something that would make anyone barf, if only for esthetic reasons.

:barney: n. In Commonwealth hackish, `barney' is to {fred} (sense #1) as {bar} is to {foo}. That is, people who commonly use `fred' as their first metasyntactic variable will often use `barney' second. The reference is, of course, to Fred Flintstone and Barney Rubble in the Flintstones cartoons.

:baroque: adj. Feature-encrusted; complex; gaudy; verging on excessive. Said of hardware or (esp.) software designs, this has many of the connotations of {elephantine} or {monstrosity} but is less extreme and not pejorative in itself. "Metafont even has features to introduce random variations to its letterform output. Now *that* is baroque!" See also {rococo}.

:BartleMUD: /bar'tl-muhd/ n. Any of the MUDs derived from the original MUD game by Richard Bartle and Roy Trubshaw (see {MUD}). BartleMUDs are noted for their (usually slightly offbeat) humor, dry but friendly syntax, and lack of adjectives in object descriptions, so a player is likely to come across `brand172', for instance (see {brand brand brand}). Bartle has taken a bad rap in some MUDding circles for supposedly originating this term, but (like the story that MUD is a trademark) this appears to be a myth; he uses `MUD1'.

:BASIC: n. A programming language, originally designed for Dartmouth's experimental timesharing system in the early 1960s, which has since become the leading cause of brain-damage in proto-hackers. This is another case (like {Pascal}) of the bad things that happen when a language deliberately designed as an educational toy gets taken too seriously. A novice can write short BASIC programs (on the order of 10--20 lines) very easily; writing anything longer is (a) very painful, and (b) encourages bad habits that will bite him/her later if he/she tries to hack in a real language. This wouldn't be so bad if historical accidents hadn't made BASIC so common on low-end micros. As it is, it ruins thousands of potential wizards a year.

:batch: adj. 1. Non-interactive. Hackers use this somewhat more loosely than the traditional technical definitions justify; in particular, switches on a normally interactive program that prepare it to receive non-interactive command input are often referred to as `batch mode' switches. A `batch file' is a series of instructions written to be handed to an interactive program running in batch mode. 2. Performance of dreary tasks all at one sitting. "I finally sat down in batch mode and wrote out checks for all those bills; I guess they'll turn the electricity back on next week..." 3. Accumulation of a number of small tasks that can be lumped together for greater efficiency. "I'm batching up those letters to send sometime" "I'm batching up bottles to take to the recycling center."

:bathtub curve: n. Common term for the curve (resembling an end-to-end section of one of those claw-footed antique bathtubs) that describes the expected failure rate of electronics with time: initially high, dropping to near 0 for most of the system's lifetime, then rising again as it `tires out'. See also {burn-in period}, {infant mortality}.

:baud: /bawd/ [simplified from its technical meaning] n. Bits per second. Hence kilobaud or Kbaud, thousands of bits per second. The technical meaning is `level transitions per second'; this coincides with bps only for two-level modulation with no framing or stop bits. Most hackers are aware of these nuances but blithely ignore them.

Histotical note: this was originally a unit of telegraph signalling speed, set at one pulse per second. It was proposed at the International Telegraph Conference of 1927, and named after J.M.E. Baudot (1845-1903), the French engineer who constructed the first successful teleprinter.

:baud barf: /bawd barf/ n. The garbage one gets on the monitor when using a modem connection with some protocol setting (esp. line speed) incorrect, or when someone picks up a voice extension on the same line, or when really bad line noise disrupts the connection. Baud barf is not completely {random}, by the way; hackers with a lot of serial-line experience can usually tell whether the device at the other end is expecting a higher or lower speed than the terminal is set to. *Really* experienced ones can identify particular speeds.

:baz: /baz/ n. 1. The third {metasyntactic variable} "Suppose we have three functions: FOO, BAR, and BAZ. FOO calls BAR, which calls BAZ...." (See also {fum}) 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'.

Earlier versions of this lexicon derived `baz' as a Stanford corruption of {bar}. However, Pete Samson (compiler of the {TMRC} lexicon) reports it was already current when he joined TMRC in 1958. He says "It came from `Pogo'. Albert the Alligator, when vexed or outraged, would shout `Bazz Fazz!' or `Rowrbazzle!' The club layout was said to model the (mythical) New England counties of Rowrfolk and Bassex (Rowrbazzle mingled with (Norfolk/Suffolk/Middlesex/Essex)."

:bboard: /bee'bord/ [contraction of `bulletin board'] n. 1. Any electronic bulletin board; esp. used of {BBS} systems running on personal micros, less frequently of a USENET {newsgroup} (in fact, use of the term for a newsgroup generally marks one either as a {newbie} fresh in from the BBS world or as a real old-timer predating USENET). 2. At CMU and other colleges with similar facilities, refers to campus-wide electronic bulletin boards. 3. The term `physical bboard' is sometimes used to refer to a old-fashioned, non-electronic cork memo board. At CMU, it refers to a particular one outside the CS Lounge.

In either of senses 1 or 2, the term is usually prefixed by the name of the intended board (`the Moonlight Casino bboard' or `market bboard'); however, if the context is clear, the better-read bboards may be referred to by name alone, as in (at CMU) "Don't post for-sale ads on general".

:BBS: /B-B-S/ [abbreviation, `Bulletin Board System'] n. An electronic bulletin board system; that is, a message database where people can log in and leave broadcast messages for others grouped (typically) into {topic group}s. Thousands of local BBS systems are in operation throughout the U.S., typically run by amateurs for fun out of their homes on MS-DOS boxes with a single modem line each. Fans of USENET and Internet or the big commercial timesharing bboards such as CompuServe and GEnie tend to consider local BBSes the low-rent district of the hacker culture, but they serve a valuable function by knitting together lots of hackers and users in the personal-micro world who would otherwise be unable to exchange code at all.