The Jargon File, Version 2.9.10, 01 Jul 1992. Various

ASCII (the 1963

       version), which had these graphics in those character positions

       rather than the modern punctuation characters.

      The `swung dash' or `approximation' sign is not quite the same as tilde in typeset material but the ASCII tilde serves for both (compare {angle brackets}).

      Some other common usages cause odd overlaps. The `#', `$', `>', and `&' characters, for example, are all pronounced "hex" in different communities because various assemblers use them as a prefix tag for hexadecimal constants (in particular, `#' in many assembler-programming cultures, `$' in the 6502 world, `>' at Texas Instruments, and `&' on the BBC Micro, Sinclair, and some Z80 machines). See also {splat}.

      The inability of ASCII text to correctly represent any of the world's other major languages makes the designers' choice of 7 bits look more and more like a serious {misfeature} as the use of international networks continues to increase (see {software rot}). Hardware and software from the U.S. still tends to embody the assumption that ASCII is the universal character set; this is a a major irritant to people who want to use a character set suited to their own languages. Perversely, though, efforts to solve this problem by proliferating `national' character sets produce an evolutionary pressure to use a *smaller* subset common to all those in use.

      :ASCII art: n. The fine art of drawing diagrams using the ASCII

       character set (mainly `|', `-', `/', `\', and

       `+'). Also known as `character graphics' or `ASCII

       graphics'; see also {boxology}. Here is a serious example:

      o——)||(—+—|<——+ +————-o + D O

       L )||( | | | C U

       A I )||( +—>|-+ | +-\/\/-+—o - T

       C N )||( | | | | P

       E )||( +—>|-+—)—-+—)|—+-o U

       )||( | | | GND T

       o——)||(—+—|<——+—————+

      A power supply consisting of a full

       wave rectifier circuit feeding a

       capacitor input filter circuit

      Figure 1.

      And here are some very silly examples:

      |\/\/\/| ____/| ___ |\_/| ___

       | | \ o.O| ACK! / \ |` '| / \ | | =()= THPHTH! / \/ \/ \ | (o)(o) U / \ C ) (__) \/\/\/\ _____ /\/\/\/ | ,___| (oo) \/ \/ | / \/———-\ U (__) /____\ || | \ /—-V `v'- oo ) / \ ||—-W|| * * |—| || |`. |_/\

      Figure 2.

      There is an important subgenre of humorous ASCII art that takes advantage of the names of the various characters to tell a pun-based joke.

      +————————————————————————————+ | ^^^^^^^^^^^^ | | ^^^^^^^^^^^ ^^^^^^^^^ | | ^^^^^^^^^^^^^ ^^^^^^^^^^^^^ | | ^^^^^^^ B ^^^^^^^^^ | | ^^^^^^^^^ ^^^ ^^^^^^^^^^^^^^ | +————————————————————————————+ " A Bee in the Carrot Patch "

      Figure 3.

      Within humorous ASCII art, there is for some reason an entire

       flourishing subgenre of pictures of silly cows. Four of these are

       reproduced in Figure 2; here are three more:

      (__) (__) (__)

       (\/) ($$) (**)

       /———-\/ /———-\/ /———-\/

       / | 666 || / |=====|| / | ||

       * ||——|| * ||——|| * ||——||

       ~~ ~~ ~~ ~~ ~~ ~~

       Satanic cow This cow is a Yuppie Cow in love

      Figure 4.

      :attoparsec: n. `atto-' is the standard SI prefix for multiplication by 10^(-18). A parsec (parallax-second) is 3.26 light-years; an attoparsec is thus 3.26 * 10^(-18) light years, or about 3.1 cm (thus, 1 attoparsec/{microfortnight} equals about 1 inch/sec). This unit is reported to be in use (though probably not very seriously) among hackers in the U.K. See {micro-}.

      :autobogotiphobia: /aw'to-boh-got`*-foh'bee-*/ n. See {bogotify}.

      :automagically: /aw-toh-maj'i-klee/ or /aw-toh-maj'i-k*l-ee/ 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. See {magic}. "The C-INTERCAL compiler generates C, then automagically invokes `cc(1)' to produce an executable."

      :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