= P =

P-mail n. Physical mail, as opposed to email. Synonymous with snail-mail.

P.O.D. /P-O-D/ Acronym for `Piece Of Data' (as opposed to a code section). Usage: pedantic and rare. See also pod.

padded cell n. Where you put lusers so they can't hurt anything. A program that limits a luser to a carefully restricted subset of the capabilities of the host system (for example, the `rsh(1)' utility on USG UNIX). Note that this is different from an iron box because it is overt and not aimed at enforcing security so much as protecting others (and the luser) from the consequences of the luser's boundless naivet'e (see naive). Also `padded cell environment'.

page in [MIT] vi.

1. To become aware of one's surroundings again after having paged out (see page out). Usually confined to the sarcastic comment: "Eric pages in, film at 11!"
2. Syn. `swap in'; see swap. <

page out [MIT] vi.

1. To become unaware of one's surroundings temporarily, due to daydreaming or preoccupation. "Can you repeat that? I paged out for a minute." See page in. Compare glitch, thinko.
2. Syn. `swap out'; see swap.

pain in the net n. A flamer.

paper-net n. Hackish way of referring to the postal service, analogizing it to a very slow, low-reliability network. USENET sig blocks sometimes include a "Paper-Net:" header just before the sender's postal address; common variants of this are "Papernet" and "P-Net". Note that the standard netiquette guidelines discourage this practice as a waste of bandwidth, since netters are quite unlikely to casually use postal addresses. Compare voice-net, snail-mail, P-Mail.

param /p*-ram'/ n. Shorthand for `parameter'. See also parm; compare arg, var.

PARC n. See XEROX PARC.

parent message n. What a followup follows up.

parity errors pl.n. Little lapses of attention or (in more severe cases) consciousness, usually brought on by having spent all night and most of the next day hacking. "I need to go home and crash; I'm starting to get a lot of parity errors." Derives from a relatively common but nearly always correctable transient error in RAM hardware. Parity errors can also afflict mass storage and serial communication lines; this is more serious because not always correctable.

Parkinson'S Law Of Data prov. "Data expands to fill the space available for storage"; buying more memory encourages the use of more memory-intensive techniques. It has been observed over the last 10 years that the memory usage of evolving systems tends to double roughly once every 18 months. Fortunately, memory density available for constant dollars also tends to double about once every 12 months (see Moore's Law); unfortunately, the laws of physics guarantee that the latter cannot continue indefinitely.

parm /parm/ n. Further-compressed form of param. This term is an IBMism, and written use is almost unknown outside IBM shops; spoken /parm/ is more widely distributed, but the synonym arg is favored among hackers. Compare arg, var.

parse [from linguistic terminology] vt.

1. To determine the syntactic structure of a sentence or other utterance (close to the standard English meaning). "That was the one I saw you." "I can't parse that."
2. More generally, to understand or comprehend. "It's very simple; you just kretch the glims and then aos the zotz." "I can't parse that."
3. Of fish, to have to remove the bones yourself. "I object to parsing fish", means "I don't want to get a whole fish, but a sliced one is okay". A `parsed fish' has been deboned. There is some controversy over whether `unparsed' should mean `bony', or also mean `deboned'.

Pascal n. An Algol-descended language designed by Niklaus Wirth on the CDC 6600 around 1967--68 as an instructional tool for elementary programming. This language, designed primarily to keep students from shooting themselves in the foot and thus extremely restrictive from a general-purpose-programming point of view, was later promoted as a general-purpose tool and, in fact, became the ancestor of a large family of languages including Modula-2 and Ada (see also bondage-and-discipline language). The hackish point of view on Pascal was probably best summed up by a devastating (and, in its deadpan way, screamingly funny) 1981 paper by Brian Kernighan (of K&R fame) entitled "Why Pascal is Not My Favorite Programming Language", which was turned down by the technical journals but circulated widely via photocopies. It was eventually published in "Comparing and Assessing Programming Languages", edited by Alan Feuer and Narain Gehani (Prentice-Hall, 1984). Part of his discussion is worth repeating here, because its criticisms are still apposite to Pascal itself after ten years of improvement and could also stand as an indictment of many other bondage-and-discipline languages. At the end of a summary of the case against Pascal, Kernighan wrote:

     9. There is no escape

     This last point is perhaps the most important.  The language is
     inadequate but circumscribed, because there is no way to escape its
     limitations.  There are no casts to disable the type-checking when
     necessary.  There is no way to replace the defective run-time
     environment with a sensible one, unless one controls the compiler
     that defines the "standard procedures".  The language is closed.

     People who use Pascal for serious programming fall into a fatal
     trap.  Because the language is impotent, it must be extended.  But
     each group extends Pascal in its own direction, to make it look
     like whatever language they really want.  Extensions for separate
     compilation, FORTRAN-like COMMON, string data types, internal
     static variables, initialization, octal numbers, bit operators,
     etc., all add to the utility of the language for one group but
     destroy its portability to others.

     I feel that it is a mistake to use Pascal for anything much beyond
     its original target.  In its pure form, Pascal is a toy language,
     suitable for teaching but not for real programming.

pastie /pay'stee/ n. An adhesive-backed label designed to be attached to a key on a keyboard to indicate some non-standard character which can be accessed through that key. Pasties are likely to be used in APL environments, where almost every key is associated with a special character. A pastie on the R key, for example, might remind the user that it is used to generate the rho character. The term properly refers to nipple-concealing devices formerly worn by strippers in concession to indecent-exposure laws; compare tits on a keyboard.

patch

1. n. A temporary addition to a piece of code, usually as a quick-and-dirty remedy to an existing bug or misfeature. A patch may or may not work, and may or may not eventually be incorporated permanently into the program. Distinguished from a diff or mod by the fact that a patch is generated by more primitive means than the rest of the program; the classical examples are instructions modified by using the front panel switches, and changes made directly to the binary executable of a program originally written in an HLL. Compare one-line fix.
2. vt. To insert a patch into a piece of code.
3. [in the UNIX world] n. A diff (sense 2).
4. A set of modifications to binaries to be applied by a patching program. IBM operating systems often receive updates to the operating system in the form of absolute hexadecimal patches. If you have modified your OS, you have to disassemble these back to the source. The patches might later be corrected by other patches on top of them (patches were said to "grow scar tissue"). The result was often a convoluted patch space and headaches galore.
5. [UNIX] the `patch(1)' program, written by Larry Wall, which automatically applies a patch (sense 3) to a set of source code.

There is a classic story of a tiger team penetrating a secure military computer that illustrates the danger inherent in binary patches (or, indeed, any patches that you can't --- or don't --- inspect and examine before installing). They couldn't find any trap doors or any way to penetrate security of IBM's OS, so they made a site visit to an IBM office (remember, these were official military types who were purportedly on official business), swiped some IBM stationery, and created a fake patch. The patch was actually the trapdoor they needed. The patch was distributed at about the right time for an IBM patch, had official stationery and all accompanying documentation, and was dutifully installed. The installation manager very shortly thereafter learned something about proper procedures.

patch space n. An unused block of bits left in a binary so that it can later be modified by insertion of machine-language instructions there (typically, the patch space is modified to contain new code, and the superseded code is patched to contain a jump or call to the patch space). The widening use of HLLs has made this term rare; it is now primarily historical outside IBM shops. See patch (sense 4), zap (sense 4), hook.

path n.

1. A bang path or explicitly routed Internet Address; a node-by-node specification of a link between two machines.
2. [UNIX] A filename, fully specified relative to the root directory (as opposed to relative to the current directory; the latter is sometimes called a `relative path'). This is also called a `pathname'.
3. [UNIX and MS-DOS] The `search path', an environment variable specifying the directories in which the shell (COMMAND.COM, under MS-DOS) should look for commands. Other, similar constructs abound under UNIX (for example, the C preprocessor has a `search path' it uses in looking for `#include' files).

pathological adj.

1. [scientific computation] Used of a data set that is grossly atypical of normal expected input, esp. one that exposes a weakness or bug in whatever algorithm one is using. An algorithm that can be broken by pathological inputs may still be useful if such inputs are very unlikely to occur in practice.
2. When used of test input, implies that it was purposefully engineered as a worst case. The implication in both senses is that the data is spectacularly ill-conditioned or that someone had to explicitly set out to break the algorithm in order to come up with such a crazy example.
3. Also said of an unlikely collection of circumstances. "If the network is down and comes up halfway through the execution of that command by root, the system may just crash." "Yes, but that's a pathological case." Often used to dismiss the case from discussion, with the implication that the consequences are acceptable, since they will happen so infrequently (if at all) that it doesn't seem worth going to the extra trouble to handle that case (see sense 1).

payware /pay'weir/ n. Commercial software. Oppose shareware or freeware.

PBD /P-B-D/ [abbrev. of `Programmer Brain Damage'] n. Applied to bug reports revealing places where the program was obviously broken by an incompetent or short-sighted programmer. Compare UBD; see also brain-damaged.

PC-ism /P-C-izm/ n. A piece of code or coding technique that takes advantage of the unprotected single-tasking environment in IBM PCs and the like, e.g., by busy-waiting on a hardware register, direct diddling of screen memory, or using hard timing loops. Compare ill-behaved, vaxism, unixism. Also, `PC-ware' n., a program full of PC-isms on a machine with a more capable operating system. Pejorative.

PD /P-D/ adj. Common abbreviation for `public domain', applied to software distributed over USENET and from Internet archive sites. Much of this software is not in fact public domain in the legal sense but travels under various copyrights granting reproduction and use rights to anyone who can snarf a copy. See copyleft.

PDL /P-D-L/, /pid'l/, /p*d'l/ or /puhd'l/

1. n. `Program Design Language'. Any of a large class of formal and profoundly useless pseudo-languages in which management forces one to design programs. Too often, management expects PDL descriptions to be maintained in parallel with the code, imposing massive overhead to little or no benefit. See also flowchart.
2. v. To design using a program design language. "I've been pdling so long my eyes won't focus beyond 2 feet."
3. n. `Page Description Language'. Refers to any language which is used to control a graphics device, usually a laserprinter. The most common example is, of course, Adobe's PostScript language, but there are many others, such as Xerox InterPress, etc.

pdl /pid'l/ or /puhd'l/ [abbreviation for `Push Down List'] n.

1. In ITS days, the preferred MITism for stack. See overflow pdl.
2. Dave Lebling, one of the co-authors of Zork; (his network address on the ITS machines was at one time pdl@dms).
3. Rarely, any sense of PDL, as these are not invariably capitalized.

PDP-10 [Programmed Data Processor model 10] n. The machine that made timesharing real. It looms large in hacker folklore because of its adoption in the mid-1970s by many university computing facilities and research labs, including the MIT AI Lab, Stanford, and CMU. Some aspects of the instruction set (most notably the bit-field instructions) are still considered unsurpassed. The 10 was eventually eclipsed by the VAX machines (descendants of the PDP-11) when DEC recognized that the 10 and VAX product lines were competing with each other and decided to concentrate its software development effort on the more profitable VAX. The machine was finally dropped from DEC's line in 1983, following the failure of the Jupiter Project at DEC to build a viable new model. (Some attempts by other companies to market clones came to nothing; see Foonly and Mars.) This event spelled the doom of ITS and the technical cultures that had spawned the original Jargon File, but by mid-1991 it had become something of a badge of honorable old-timerhood among hackers to have cut one's teeth on a PDP-10. See TOPS-10, ITS, AOS, BLT, DDT, DPB, EXCH, HAKMEM, JFCL, LDB, pop, push, Appendix A.

PDP-20 n. The most famous computer that never was. PDP-10 computers running the TOPS-10 operating system were labeled `DECsystem-10' as a way of differentiating them from the PDP-11. Later on, those systems running TOPS-20 were labeled `DECSYSTEM-20' (the block capitals being the result of a lawsuit brought against DEC by Singer, which once made a computer called `system-10'), but contrary to popular lore there was never a `PDP-20'; the only difference between a 10 and a 20 was the operating system and the color of the paint. Most (but not all) machines sold to run TOPS-10 were painted `Basil Blue', whereas most TOPS-20 machines were painted `Chinese Red' (often mistakenly called orange).

peek n.,vt. (and poke) The commands in most microcomputer BASICs for directly accessing memory contents at an absolute address; often extended to mean the corresponding constructs in any HLL (peek reads memory, poke modifies it). Much hacking on small, non-MMU micros consists of `peek'ing around memory, more or less at random, to find the location where the system keeps interesting stuff. Long (and variably accurate) lists of such addresses for various computers circulate (see interrupt list, the). The results of `poke's at these addresses may be highly useful, mildly amusing, useless but neat, or (most likely) total lossage (see killer poke).

Since a real operating system provides useful, higher-level services for the tasks commonly performed with peeks and pokes on micros, and real languages tend not to encourage low-level memory groveling, a question like "How do I do a peek in C?" is diagnostic of the newbie. (Of course, OS kernels often have to do exactly this; a real C hacker would unhesitatingly, if unportably, assign an absolute address to a pointer variable and indirect through it.)

pencil and paper n. An archaic information storage and transmission device that works by depositing smears of graphite on bleached wood pulp. More recent developments in paper-based technology include improved `write-once' update devices which use tiny rolling heads similar to mouse balls to deposit colored pigment. All these devices require an operator skilled at so-called `handwriting' technique. These technologies are ubiquitous outside hackerdom, but nearly forgotten inside it. Most hackers had terrible handwriting to begin with, and years of keyboarding tend to have encouraged it to degrade further. Perhaps for this reason, hackers deprecate pencil-and-paper technology and often resist using it in any but the most trivial contexts. See also Appendix B.

peon n. A person with no special (root or wheel) privileges on a computer system. "I can't create an account on *foovax* for you; I'm only a peon there."

percent-S /per-sent' es'/ [From the code in C's `printf(3)' library function used to insert an arbitrary string argument] n. An unspecified person or object. "I was just talking to some percent-s in administration." Compare random.

perf /perf/ n. Syn. chad (sense 1). The term `perfory' /per'f*-ree/ is also heard. The term perf may also refer to the perforations themselves, rather than the chad they produce when torn.

perfect programmer syndrome n. Arrogance; the egotistical conviction that one is above normal human error. Most frequently found among programmers of some native ability but relatively little experience (especially new graduates; their perceptions may be distorted by a history of excellent performance at solving toy problems). "Of course my program is correct, there is no need to test it." "Yes, I can see there may be a problem here, but *I'll* never type `rm -r /' while in root mode."

Perl /perl/ [Practical Extraction and Report Language, a.k.a Pathologically Eclectic Rubbish Lister] n. An interpreted language developed by Larry Wall , author of `patch(1)' and `rn(1)') and distributed over USENET. Superficially resembles `awk(1)', but is much hairier (see awk). UNIX sysadmins, who are almost always incorrigible hackers, increasingly consider it one of the languages of choice. Perl has been described, in a parody of a famous remark about `lex(1)', as the "Swiss-Army chainsaw" of UNIX programming.

person of no account [University of California at Santa Cruz] n. Used when referring to a person with no network address, frequently to forestall confusion. Most often as part of an introduction: "This is Bill, a person of no account, but he used to be bill@random.com". Compare return from the dead.

pessimal /pes'im-l/ [Latin-based antonym for `optimal'] adj. Maximally bad. "This is a pessimal situation." Also `pessimize' vt. To make as bad as possible. These words are the obvious Latin-based antonyms for `optimal' and `optimize', but for some reason they do not appear in most English dictionaries, although `pessimize' is listed in the OED.

pessimizing compiler /pes'*-mi:z`ing k*m-pi:l'r/ [antonym of `optimizing compiler'] n. A compiler that produces object code that is worse than the straightforward or obvious hand translation. The implication is that the compiler is actually trying to optimize the program, but through excessive cleverness is doing the opposite. A few pessimizing compilers have been written on purpose, however, as pranks or burlesques.

peta- /pe't*/ [SI] pref. See quantifiers.

PETSCII /pet'skee/ [abbreviation of PET ASCII] n. The variation (many would say perversion) of the ASCII character set used by the Commodore Business Machines PET series of personal computers and the later Commodore C64, C16, and C128 machines. The PETSCII set used left-arrow and up-arrow (as in old-style ASCII) instead of underscore and caret, placed the unshifted alphabet at positions 65--90, put the shifted alphabet at positions 193--218, and added graphics characters.

phage n. A program that modifies other programs or databases in unauthorized ways; esp. one that propagates a virus or Trojan Horse. See also worm, mockingbird. The analogy, of course, is with phage viruses in biology.

phase

1. n. The offset of one's waking-sleeping schedule with respect to the standard 24-hour cycle; a useful concept among people who often work at night and/or according to no fixed schedule. It is not uncommon to change one's phase by as much as 6 hours per day on a regular basis. "What's your phase?" "I've been getting in about 8 P.M. lately, but I'm going to wrap around to the day schedule by Friday." A person who is roughly 12 hours out of phase is sometimes said to be in `night mode'. (The term `day mode' is also (but less frequently) used, meaning you're working 9 to 5 (or, more likely, 10 to 6).) The act of altering one's cycle is called `changing phase'; `phase shifting' has also been recently reported from Caltech.
2. `change phase the hard way': To stay awake for a very long time in order to get into a different phase.
3. `change phase the easy way': To stay asleep, etc. However, some claim that either staying awake longer or sleeping longer is easy, and that it is *shortening* your day or night that is really hard (see wrap around). The `jet lag' that afflicts travelers who cross many time-zone boundaries may be attributed to two distinct causes: the strain of travel per se, and the strain of changing phase. Hackers who suddenly find that they must change phase drastically in a short period of time, particularly the hard way, experience something very like jet lag without traveling.

phase of the moon n. Used humorously as a random parameter on which something is said to depend. Sometimes implies unreliability of whatever is dependent, or that reliability seems to be dependent on conditions nobody has been able to determine. "This feature depends on having the channel open in mumble mode, having the foo switch set, and on the phase of the moon." See also heisenbug.

True story: Once upon a time there was a bug that really did depend on the phase of the moon. There was a little subroutine that had traditionally been used in various programs at MIT to calculate an approximation to the moon's true phase. GLS incorporated this routine into a LISP program that, when it wrote out a file, would print a timestamp line almost 80 characters long. Very occasionally the first line of the message would be too long and would overflow onto the next line, and when the file was later read back in the program would barf. The length of the first line depended on both the precise date and time and the length of the phase specification when the timestamp was printed, and so the bug literally depended on the phase of the moon!

The first paper edition of the Jargon File (Steele-1983) included an example of one of the timestamp lines that exhibited this bug, but the typesetter `corrected' it. This has since been described as the phase-of-the-moon-bug bug.

phase-wrapping [MIT] n. Syn. wrap around, sense 2.

phreaking /freek'ing/ [from `phone phreak'] n.

1. The art and science of cracking the phone network (so as, for example, to make free long-distance calls).
2. By extension, security-cracking in any other context (especially, but not exclusively, on communications networks) (see cracking).

At one time phreaking was a semi-respectable activity among hackers; there was a gentleman's agreement that phreaking as an intellectual game and a form of exploration was OK, but serious theft of services was taboo. There was significant crossover between the hacker community and the hard-core phone phreaks who ran semi-underground networks of their own through such media as the legendary "TAP Newsletter". This ethos began to break down in the mid-1980s as wider dissemination of the techniques put them in the hands of less responsible phreaks. Around the same time, changes in the phone network made old-style technical ingenuity less effective as a way of hacking it, so phreaking came to depend more on overtly criminal acts such as stealing phone-card numbers. The crimes and punishments of gangs like the `414 group' turned that game very ugly. A few old-time hackers still phreak casually just to keep their hand in, but most these days have hardly even heard of `blue boxes' or any of the other paraphernalia of the great phreaks of yore.

pico- [SI: a quantifier meaning * 10^-12] pref. Smaller than nano-; used in the same rather loose connotative way as nano- and micro-. This usage is not yet common in the way nano- and micro- are, but should be instantly recognizable to any hacker. See also quantifiers, micro-.

pig, run like a v. To run very slowly on given hardware, said of software. Distinct from hog.

pilot error [Sun: from aviation] n. A user's misconfiguration or misuse of a piece of software, producing apparently buglike results (compare UBD). "Joe Luser reported a bug in sendmail that causes it to generate bogus headers." "That's not a bug, that's pilot error. His `sendmail.cf' is hosed."

ping [from the TCP/IP acronym `Packet INternet Groper', prob. originally contrived to match the submariners' term for a sonar pulse]

1. n. Slang term for a small network message (ICMP ECHO) sent by a computer to check for the presence and alertness of another (the UNIX command `ping(8)' can be used to do this manually). Occasionally used as a phone greeting. See ACK, also ENQ.
2. vt. To verify the presence of.
3. vt. To get the attention of.
4. vt. To send a message to all members of a mailing list requesting an ACK (in order to verify that everybody's addresses are reachable). "We haven't heard much of anything from Geoff, but he did respond with an ACK both times I pinged jargon-friends."
5. n. A quantum packet of happiness. People who are very happy tend to exude pings; furthermore, one can intentionally create pings and aim them at a needy party (e.g., a depressed person). This sense of ping may appear as an exclamation; "Ping!" (I'm happy; I am emitting a quantum of happiness; I have been struck by a quantum of happiness). The form "pingfulness", which is used to describe people who exude pings, also occurs. (In the standard abuse of language, "pingfulness" can also be used as an exclamation, in which case it's a much stronger exclamation than just "ping"!). Oppose blargh.

The funniest use of `ping' to date was described in January 1991 by Steve Hayman on the USENET group comp.sys.next. He was trying to isolate a faulty cable segment on a TCP/IP Ethernet hooked up to a NeXT machine, and got tired of having to run back to his console after each cabling tweak to see if the ping packets were getting through. So he used the sound-recording feature on the NeXT, then wrote a script that repeatedly invoked `ping(8)', listened for an echo, and played back the recording on each returned packet. Result? A program that caused the machine to repeat, over and over, "Ping ... ping ... ping ..." as long as the network was up. He turned the volume to maximum, ferreted through the building with one ear cocked, and found a faulty tee connector in no time.

Pink-Shirt Book "The Peter Norton Programmer's Guide to the IBM PC". The original cover featured a picture of Peter Norton with a silly smirk on his face, wearing a pink shirt. Perhaps in recognition of this usage, the current edition has a different picture of Norton wearing a pink shirt. See also book titles.

PIP /pip/ [Peripheral Interchange Program] vt.,obs. To copy; from the program PIP on CP/M, RSX-11, RSTS/E, TOPS-10, and OS/8 (derived from a utility on the PDP-6) that was used for file copying (and in OS/8 and RT-11 for just about every other file operation you might want to do). It is said that when the program was originated, during the development of the PDP-6 in 1963, it was called ATLATL (`Anything, Lord, to Anything, Lord'; this played on the Nahuatl word `atlatl' for a spear-thrower, with connotations of utility and primitivity that were no doubt quite intentional). See also BLT, dd, cat.

pistol [IBM] n. A tool that makes it all too easy for you to shoot yourself in the foot. "UNIX `rm *' makes such a nice pistol!"

pizza box [Sun] n. The largish thin box housing the electronics in (especially Sun) desktop workstations, so named because of its size and shape and the dimpled pattern that looks like air holes.

Two meg single-platter removable disk packs used to be called pizzas, and the huge drive they were stuck into was referred to as a pizza oven. It's an index of progress that in the old days just the disk was pizza-sized, while now the entire computer is.

Pizza, ANSI Standard /an'see stan'd*rd peet'z*/ [CMU] Pepperoni and mushroom pizza. Coined allegedly because most pizzas ordered by CMU hackers during some period leading up to mid-1990 were of that flavor. See also rotary debugger; compare Tea, ISO Standard Cup Of.

plaid screen [XEROX PARC] n. A `special effect' that occurs when certain kinds of memory smashes overwrite the control blocks or image memory of a bit-mapped display. The term "salt and pepper" may refer to a different pattern of similar origin. Though the term as coined at PARC refers to the result of an error, some of the X demos induce plaid-screen effects deliberately as a display hack.

plain-ASCII /playn-as'kee/ Syn. Flat-ASCII.

plan file [UNIX] n. On systems that support finger, the `.plan' file in a user's home directory is displayed when the user is fingered. This feature was originally intended to be used to keep potential fingerers apprised of one's location and near-future plans, but has been turned almost universally to humorous and self-expressive purposes (like a sig block). See also Hacking X For Y.

A recent innovation in plan files has been the introduction of "scrolling plan files" which are one-dimensional animations made using only the printable ASCII character set, carriage return and line feed, avoiding terminal specific escape sequences, since the finger command will (for security reasons; see letterbomb) not pass the escape character.

Scrolling .plan files have become art forms in miniature, and some sites have started competitions to find who can create the longest running, funniest, and most original animations. Various animation characters include:

     Centipede:
          mmmmme
     Lorry/Truck:
          oo-oP
     Andalusian Video Snail:
          _@/

platinum-iridium adj. Standard, against which all others of the same category are measured. Usage: silly. The notion is that one of whatever it is has actually been cast in platinum-iridium alloy and placed in the vault beside the Standard Kilogram at the International Bureau of Weights and Measures near Paris. (From 1889 to 1960, the meter was defined to be the distance between two scratches in a platinum-iridium bar kept in that same vault --- this replaced an earlier definition as 10^(-7) times the distance between the North Pole and the Equator along a meridian through Paris; unfortunately, this had been based on an inexact value of the circumference of the Earth. From 1960 to 1984 it was defined to be 1650763.73 wavelengths of the orange-red line of krypton-86 propagating in a vacuum. It is now defined as the length of the path traveled by light in a vacuum in the time interval of 1/299,792,458 of a second. The kilogram is now the only unit of measure officially defined in terms of a unique artifact.) "This garbage-collection algorithm has been tested against the platinum-iridium cons cell in Paris." Compare golden.

playpen [IBM] n. A room where programmers work. Compare salt mines.

playte /playt/ 16 bits, by analogy with nybble and byte. Usage: rare and extremely silly. See also dynner and crumb.

plingnet /pling'net/ n. Syn. UUCPNET. Also see Commonwealth Hackish, which uses `pling' for bang (as in bang path).

plokta /plok't*/ [Acronym for `Press Lots Of Keys To Abort'] v. To press random keys in an attempt to get some response from the system. One might plokta when the abort procedure for a program is not known, or when trying to figure out if the system is just sluggish or really hung. Plokta can also be used while trying to figure out any unknown key sequence for a particular operation. Someone going into `plokta mode' usually places both hands flat on the keyboard and mashes them down, hoping for some useful response.

A slightly more directed form of plokta can often be seen in mail messages or USENET articles from new users --- the text might end with

             ^X^C       
             q  
             quit       
             :q 
             ^C 
             end        
             x  
             exit       
             ZZ 
             ^D 
             ?  
             help

plonk [USENET: possibly influenced by British slang `plonk' for cheap booze, or `plonker' for someone behaving stupidly] The sound a newbie makes as he falls to the bottom of a kill file. Used almost exclusively in the newsgroup talk.bizarre, this term (usually written "*plonk*") is a form of public ridicule.

plugh /ploogh/ [from the ADVENT game] v. See xyzzy.

plumbing [UNIX] n. Term used for shell code, so called because of the prevalence of `pipelines' that feed the output of one program to the input of another. Under UNIX, user utilities can often be implemented or at least prototyped by a suitable collection of pipelines and temp-file grinding encapsulated in a shell script; this is much less effort than writing C every time, and the capability is considered one of UNIX's major winning features. A few other OSs such as IBM's VM/CMS support similar facilities. Esp. used in the construction `hairy plumbing' (see hairy). "You can kluge together a basic spell-checker out of `sort(1)', `comm(1)', and `tr(1)' with a little plumbing." See also tee.

PM /P-M/

1. v. (from `preventive maintenance') To bring down a machine for inspection or test purposes. See provocative maintenance; see also scratch monkey.
2. n. Abbrev. for `Presentation Manager', an elephantine OS/2 graphical user interface.

pnambic /p*-nam'bik/ [Acronym from the scene in the film version of "The Wizard of Oz" in which the true nature of the wizard is first discovered: "Pay no attention to the man behind the curtain."]

1. A stage of development of a process or function that, owing to incomplete implementation or to the complexity of the system, requires human interaction to simulate or replace some or all of the actions, inputs, or outputs of the process or function.
2. Of or pertaining to a process or function whose apparent operations are wholly or partially falsified.
3. Requiring prestidigitization.

The ultimate pnambic product was "Dan Bricklin's Demo", a program which supported flashy user-interface design prototyping. There is a related maxim among hackers: "Any sufficiently advanced technology is indistinguishable from a rigged demo." See magic, sense 1, for illumination of this point.

pod [allegedly from abbreviation POD for `Prince Of Darkness'] n. A Diablo 630 (or, latterly, any letter-quality impact printer). From the DEC-10 PODTYPE program used to feed formatted text to it. Not to be confused with P.O.D..

point-and-drool interface n. Parody of the techspeak term `point-and-shoot interface', describing a windows, icons, and mouse-based interface such as is found on the Macintosh. The implication, of course, is that such an interface is only suitable for idiots. See for the rest of us, WIMP Environment, Macintrash, drool-proof paper. Also `point-and-grunt interface'.

poke n.,vt. See peek.

poll v.,n.

1. [techspeak] The action of checking the status of an input line, sensor, or memory location to see if a particular external event has been registered.
2. To repeatedly call or check with someone: "I keep polling him, but he's not answering his phone; he must be swapped out."
3. To ask. "Lunch? I poll for a takeout order daily."

polygon pusher n. A chip designer who spends most of his or her time at the physical layout level (which requires drawing *lots* of multi-colored polygons). Also `rectangle slinger'.

POM /P-O-M/ n. Common abbreviation for phase of the moon. Usage: usually in the phrase `POM-dependent', which means flaky.

pop /pop/ [from the operation that removes the top of a stack, and the fact that procedure return addresses are usually saved on the stack] (also capitalized `POP')

1. vt. To remove something from a stack or pdl. If a person says he/she has popped something from his stack, that means he/she has finally finished working on it and can now remove it from the list of things hanging overhead.
2. When a discussion gets to a level of detail so deep that the main point of the discussion is being lost, someone will shout "Pop!", meaning "Get back up to a higher level!" The shout is frequently accompanied by an upthrust arm with a finger pointing to the ceiling.

POPJ /pop'J/ [from a PDP-10 return-from-subroutine instruction] n.,v. To return from a digression. By verb doubling, "Popj, popj" means roughly "Now let's see, where were we?" See RTI.

post v. To send a message to a mailing list or newsgroup. Distinguished in context from `mail'; one might ask, for example: "Are you going to post the patch or mail it to known users?"

postcardware n. Shareware that borders on freeware, in that the author requests only that satisfied users send a postcard of their home town or something. (This practice, silly as it might seem, serves to remind users that they are otherwise getting something for nothing, and may also be psychologically related to real estate `sales' in which $1 changes hands just to keep the transaction from being a gift.)

posting n. Noun corresp. to v. post (but note that post can be nouned). Distinguished from a `letter' or ordinary email message by the fact that it is broadcast rather than point-to-point. It is not clear whether messages sent to a small mailing list are postings or email; perhaps the best dividing line is that if you don't know the names of all the potential recipients, it is a posting.

postmaster n. The email contact and maintenance person at a site connected to the Internet or UUCPNET. Often, but not always, the same as the admin. The Internet standard for electronic mail (RFC-822) requires each machine to have a `postmaster' address; usually it is aliased to this person.

PostScript n. A Page Description Language (PDL), based on work originally done by John Gaffney at Evans and Sutherland in 1976, evolving through `JaM' (`John and Martin', Martin Newell) at XEROX PARC, and finally implemented in its current form by John Warnock et al. after he and Chuck Geschke founded Adobe Systems Incorporated in 1982. PostScript gets its leverage by using a full programming language, rather than a series of low-level escape sequences, to describe an image to be printed on a laser printer or other output device (in this it parallels EMACS, which exploited a similar insight about editing tasks). It is also noteworthy for implementing on-the fly rasterization, from Bezier curve descriptions, of high-quality fonts at low (e.g. 300 dpi) resolution (it was formerly believed that hand-tuned bitmap fonts were required for this task). Hackers consider PostScript to be among the most elegant hacks of all time, and the combination of technical merits and widespread availability has made PostScript the language of choice for graphical output.

pound on vt. Syn. bang on.

power cycle vt. (also, `cycle power' or just `cycle') To power off a machine and then power it on immediately, with the intention of clearing some kind of hung or gronked state. Syn. 120 reset; see also Big Red Switch. Compare Vulcan Nerve Pinch, bounce (sense 4), and boot, and see the AI Koan in "A Selection Of AI Koans" (in Appendix A) about Tom Knight and the novice.

power hit n. A spike or drop-out in the electricity supplying your machine; a power glitch. These can cause crashes and even permanent damage to your machine(s).

PPN /P-P-N/, /pip'n/ [from `Project-Programmer Number'] n. A user-ID under TOPS-10 and its various mutant progeny at SAIL, BBN, CompuServe, and elsewhere. Old-time hackers from the PDP-10 era sometimes use this to refer to user IDs on other systems as well.

precedence lossage /pre's*-dens los'*j/ [C programmers] n. Coding error in an expression due to unexpected grouping of arithmetic or logical operators by the compiler. Used esp. of certain common coding errors in C due to the nonintuitively low precedence levels of `&', `|', `^', `<<', and `>>' (for this reason, experienced C programmers deliberately forget the language's baroque precedence hierarchy and parenthesize defensively). Can always be avoided by suitable use of parentheses. LISP fans enjoy pointing out that this can't happen in *their* favorite language, which eschews precedence entirely, requiring one to use explicit parentheses everywhere. See aliasing bug, memory leak, memory smash, smash the stack, fandango on core, overrun screw.

prepend /pree`pend'/ [by analogy with `append'] vt. To prefix. As with `append' (but not `prefix' or `suffix' as a verb), the direct object is always the thing being added and not the original word (or character string, or whatever). "If you prepend a semicolon to the line, the translation routine will pass it through unaltered."

prestidigitization /pres`t*-di`j*-ti:-zay'sh*n/ n.

1. The act of putting something into digital notation via sleight of hand.
2. Data entry through legerdemain.

pretty pictures n. [scientific computation] The next step up from numbers. Interesting graphical output from a program that may not have any sensible relationship to the system the program is intended to model. Good for showing to management.

prettyprint /prit'ee-print/ (alt. `pretty-print') v.

1. To generate `pretty' human-readable output from a hairy internal representation; esp. used for the process of grinding (sense 1) program code, and most esp. for LISP code.
2. To format in some particularly slick and nontrivial way.

pretzel key [Mac users] n. See feature key.

prime time [from TV programming] n. Normal high-usage hours on a timesharing system; the day shift. Avoidance of prime time was traditionally given as a major reason for night mode hacking. The rise of the personal workstation has rendered this term, along with timesharing itself, almost obsolete. The hackish tendency to late-night hacking runs has changed not a bit.

printing discussion [XEROX PARC] n. A protracted, low-level, time-consuming, generally pointless discussion of something only peripherally interesting to all.

priority interrupt [from the hardware term] n. Describes any stimulus compelling enough to yank one right out of hack mode. Classically used to describe being dragged away by an SO for immediate sex, but may also refer to more mundane interruptions such as a fire alarm going off in the near vicinity. Also called an NMI (non-maskable interrupt), especially in PC-land.

profile n.

1. A control file for a program, esp. a text file automatically read from each user's home directory and intended to be easily modified by the user in order to customize the program's behavior. Used to avoid hardcoded choices (see also dot file, rc file).
2. [techspeak] A report on the amounts of time spent in each routine of a program, used to find and tune away the hot spots in it. This sense is often verbed. Some profiling modes report units other than time (such as call counts) and/or report at granularities other than per-routine, but the idea is similar.

proglet /prog'let/ [UK] n. A short extempore program written to meet an immediate, transient need. Often written in BASIC, rarely more than a dozen lines long, and containing no subroutines. The largest amount of code that can be written off the top of one's head, that does not need any editing, and that runs correctly the first time (this amount varies significantly according to one's skill and the language one is using). Compare toy program, noddy, one-liner wars.

program n.

1. A magic spell cast over a computer allowing it to turn one's input into error messages.
2. An exercise in experimental epistemology.
3. A form of art, ostensibly intended for the instruction of computers, which is nevertheless almost inevitably a failure if other programmers can't understand it.

Programmer'S Cheer "Shift to the left! Shift to the right! Pop up, push down! Byte! Byte! Byte!" A joke so old it has hair on it.

programming n.

1. The art of debugging a blank sheet of paper (or, in these days of on-line editing, the art of debugging an empty file).
2. A pastime similar to banging one's head against a wall, but with fewer opportunities for reward.
3. The most fun you can have with your clothes on (although clothes are not mandatory).

programming fluid n.

1. Coffee.
2. Cola.
3. Any caffeinacious stimulant.

propeller head n. Used by hackers, this is syn. with computer geek. Non-hackers sometimes use it to describe all techies. Prob. derives from SF fandom's tradition (originally invented by old-time fan Ray Faraday Nelson) of propeller beanies as fannish insignia (though nobody actually wears them except as a joke).

propeller key [Mac users] n. See feature key.

proprietary adj.

1. In marketroid-speak, superior; implies a product imbued with exclusive magic by the unmatched brilliance of the company's own hardware or software designers.
2. In the language of hackers and users, inferior; implies a product not conforming to open-systems standards, and thus one that puts the customer at the mercy of a vendor able to gouge freely on service and upgrade charges after the initial sale has locked the customer in.

protocol n. As used by hackers, this never refers to niceties about the proper form for addressing letters to the Papal Nuncio or the order in which one should use the forks in a Russian-style place setting; hackers don't care about such things. It is used instead to describe any set of rules that allow different machines or pieces of software to coordinate with each other without ambiguity. So, for example, it does include niceties about the proper form for addressing packets on a network or the order in which one should use the forks in the Dining Philosophers Problem. It implies that there is some common message format and an accepted set of primitives or commands that all parties involved understand, and that transactions among them follow predictable logical sequences. See also handshaking, do protocol.

provocative maintenance [common ironic mutation of `preventive maintenance'] n. Actions performed upon a machine at regularly scheduled intervals to ensure that the system remains in a usable state. So called because it is all too often performed by a field servoid who doesn't know what he is doing; such `maintenance' often *induces* problems, or otherwise results in the machine's remaining in an *un*usable state for an indeterminate amount of time. See also scratch monkey.

prowler [UNIX] n. A daemon that is run periodically (typically once a week) to seek out and erase core files, truncate administrative logfiles, nuke `lost+found' directories, and otherwise clean up the cruft that tends to pile up in the corners of a file system. See also GFR, reaper, skulker.

pseudo /soo'doh/ [USENET: truncation of `pseudonym'] n.

1. An electronic-mail or USENET persona adopted by a human for amusement value or as a means of avoiding negative repercussions of one's net.behavior; a `nom de USENET', often associated with forged postings designed to conceal message origins. Perhaps the best-known and funniest hoax of this type is BIFF.
2. Notionally, a flamage-generating AI program simulating a USENET user. Many flamers have been accused of actually being such entities, despite the fact that no AI program of the required sophistication yet exists. However, in 1989 there was a famous series of forged postings that used a phrase-frequency-based travesty generator to simulate the styles of several well-known flamers; it was based on large samples of their back postings (compare Dissociated Press). A significant number of people were fooled by the forgeries, and the debate over their authenticity was settled only when the perpetrator came forward to publicly admit the hoax.

pseudoprime n. A backgammon prime (six consecutive occupied points) with one point missing. This term is an esoteric pun derived from a mathematical method that, rather than determining precisely whether a number is prime (has no divisors), uses a statistical technique to decide whether the number is `probably' prime. A number that passes this test is called a pseudoprime. The hacker backgammon usage stems from the idea that a pseudoprime is almost as good as a prime: it does the job of a prime until proven otherwise, and that probably won't happen.

pseudosuit /soo'doh-s[y]oot`/ n. A suit wannabee; a hacker who has decided that he wants to be in management or administration and begins wearing ties, sport coats, and (shudder!) suits voluntarily. It's his funeral. See also lobotomy.

psychedelicware /si:`k*-del'-ik-weir/ [UK] n. Syn. display hack. See also smoking clover.

psyton /si:'ton/ [TMRC] n. The elementary particle carrying the sinister force. The probability of a process losing is proportional to the number of psytons falling on it. Psytons are generated by observers, which is why demos are more likely to fail when lots of people are watching. [This term appears to have been largely superseded by bogon; see also quantum bogodynamics. --- ESR]

pubic directory [NYU] (also `pube directory' /pyoob' d*-rek't*-ree/) n. The `pub' (public) directory on a machine that allows FTP access. So called because it is the default location for SEX (sense 1). "I'll have the source in the pube directory by Friday."

puff vt. To decompress data that has been crunched by Huffman coding. At least one widely distributed Huffman decoder program was actually *named* `PUFF', but these days it is usually packaged with the encoder. Oppose huff.

punched card alt. `punch card' [techspeak] n.obs. The signature medium of computing's Stone Age, now obsolescent outside of some IBM shops. The punched card actually predated computers considerably, originating in 1801 as a control device for mechanical looms. The version patented by Hollerith and used with mechanical tabulating machines in the 1890 U.S. Census was a piece of cardboard about 90 mm by 215 mm. There is a widespread myth that it was designed to fit in the currency trays used for that era's larger dollar bills, but recent investigations have falsified this.

IBM (which originated as a tabulating-machine manufacturer) married the punched card to computers, encoding binary information as patterns of small rectangular holes; one character per column, 80 columns per card. Other coding schemes, sizes of card, and hole shapes were tried at various times.

The 80-column width of most character terminals is a legacy of the IBM punched card; so is the size of the quick-reference cards distributed with many varieties of computers even today. See chad, chad box, eighty-column mind, green card, dusty deck, lace card, card walloper.

punt [from the punch line of an old joke referring to American football: "Drop back 15 yards and punt!"] v.

1. To give up, typically without any intention of retrying. "Let's punt the movie tonight." "I was going to hack all night to get this feature in, but I decided to punt" may mean that you've decided not to stay up all night, and may also mean you're not ever even going to put in the feature.
2. More specifically, to give up on figuring out what the Right Thing is and resort to an inefficient hack.
3. A design decision to defer solving a problem, typically because one cannot define what is desirable sufficiently well to frame an algorithmic solution. "No way to know what the right form to dump the graph in is --- we'll punt that for now."
4. To hand a tricky implementation problem off to some other section of the design. "It's too hard to get the compiler to do that; let's punt to the runtime system."

Purple Book n.

1. The "System V Interface Definition". The covers of the first editions were an amazingly nauseating shade of off-lavender.
2. Syn. Wizard Book. See also book titles.

purple wire [IBM] n. Wire installed by Field Engineers to work around problems discovered during testing or debugging. These are called `purple wires' even when (as is frequently the case) their actual physical color is yellow.... Compare blue wire, yellow wire, and red wire.

push [from the operation that puts the current information on a stack, and the fact that procedure return addresses are saved on a stack] (Also PUSH /push/ or PUSHJ /push'J/, the latter based on the PDP-10 procedure call instruction.)

1. To put something onto a stack or pdl. If one says that something has been pushed onto one's stack, it means that the Damoclean list of things hanging over ones's head has grown longer and heavier yet. This may also imply that one will deal with it *before* other pending items; otherwise one might say that the thing was `added to my queue'.
2. vi. To enter upon a digression, to save the current discussion for later. Antonym of pop; see also stack, pdl.