= P =
=====

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 {luser}s 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 na"ivet'e (see
   {na"ive}).  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."  See {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 block}s not uncommonly include a "Paper-Net:" header just
   before the sender's postal address; common variants of this are
   "Papernet" and "P-Net".  Compare {voice-net}, {snail-mail}.

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

parent message: n. See {followup}.

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.

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 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 never formally
   published but has circulated widely via photocopies.  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.

   Pascal has since been almost entirely displaced (by {C}) from the
   niches it had acquired in serious applications and systems
   programming, but retains some popularity as a hobbyist language in
   the MS-DOS and Macintosh worlds.

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.

   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 that you can't --- or don't --- inspect
   and examine before installing).  They couldn't find any {trap
   door}s 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 that they will happen so
   infrequently (if at all) that there is no justification for
   going to 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: /pid'l/ or /puhd'l/ [acronym for `Push Down List'] 1. In
   ITS days, the preferred MITism for {stack}.  2. Dave Lebling, one
   of the co-authors of {Zork}; (his {network address} on the ITS
   machines was at one time pdl@dms).  3. `Program Design Language'.
   Any of a large class of formal and profoundly useless
   pseudo-languages in which {management} forces one to design
   programs.  {Management} often expects it to be maintained in
   parallel with the code.  See also {{flowchart}}.  4. To design
   using a program design language.  "I've been pdling so long my
   eyes won't focus beyond 2 feet."

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}) 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}).

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. See {chad} (sense 1).  The term `perfory'
   /per'f*-ree/ is also heard.

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
   problem}s).  "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}."

Perl: /perl/ [Practical Extraction and Report Language, a.k.a
   Pathologically Eclectic Rubbish Lister] n. An interpreted language
   developed by Larry Wall (lwall@jpl.nasa.gov, 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.

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.

phase: 1. n. The phase of one's waking-sleeping schedule with
   respect to the standard 24-hour cycle.  This is 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's 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."

   True story: Once upon a time there was a bug that really did depend
   on the phase of the moon.  There is 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.

phreaking: [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).

   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 aliveness of
   another.  Occasionally used as a phone greeting.  See {ACK},
   also {ENQ}.  2. vt. To verify the presence of.  3. vt. To get
   the attention of.  From the UNIX command `ping(1)' that sends
   an ICMP ECHO packet to another host.  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."

   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, 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').

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}.

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 {Hacking X
   for Y}.

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 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 presses down, hoping for some useful
   response.

plonk: [USENET: possibly influenced by British slang `plonk' for
   cheap booze] 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.  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 {scratch
   monkey}.  2. n. Abbrev. for `Presentation Manager', an
   {elephantine} OS/2 graphical user interface.  See also
   {provocative maintenance}.

pnambic: /p*-nam'bik/ [Acronym from the scene in the film
   version of `The Wizard of Oz' in which 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 acronym 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.
   See also {P.O.D.}

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 acronym for {phase of the moon}.  Usage:
   usually in the phrase `POM-dependent', which means {flaky}.

pop: [from the operation that removes the top of a stack, and the
   fact that procedure return addresses are saved on the stack] (also
   capitalized `POP' /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 too deep a level of detail
   so 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}.

posing: n. On a {MUD}, the use of `:' or an equivalent
   command to announce to other players that one is taking a certain
   physical action that has no effect on the game (it may, however,
   serve as a social signal or propaganda device that induces other
   people to take game actions).  For example, if one's character name
   is Firechild, one might type `: looks delighted at the idea and
   begins hacking on the nearest terminal' to broadcast a message that
   says "Firechild looks delighted at the idea and begins hacking on
   the nearest terminal".  See {RL}.

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?"

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}.  It is conventional for each machine to have
   a `postmaster' address that is aliased to this person.

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 {gronk}ed state.
   Syn. {120 reset}; see also {Big Red Switch}.  Compare
   {Vulcan nerve pinch}, {bounce}, and {boot}, and see the
   AI Koan in appendix A about Tom Knight and the novice.

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}, {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 {grind}ing (sense 2)
   LISP code.  2. To format in some particularly slick and
   nontrivial way.

pretzel key: [Mac users] n. See {command key}.

prime time: [from TV programming] n. Normal high-usage hours on a
   timesharing system; the day shift.  Avoidance of prime time is a
   major reason for {night mode} hacking.

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.  2. [techspeak] A
   report on the amounts of time spent in each routine of a program,
   used to find and {tune} away the {hot spot}s 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 contains 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 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. n. A pastime similar to banging one's head against a
   wall, but with fewer opportunities for reward.  3. n. The most fun
   you can have with your clothes on (although clothes are not
   mandatory).

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 {command key}.

proprietary: adj. 1. In {marketroid}-speak, superior; implies a
   product imbued with exclusive magic by the unmatched brilliance of
   the company's 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 (that's
   assuming it wasn't too expensive in the first place).

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; this 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, designed to fit exactly in the
   currency trays used for that era's larger dollar bills.

   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. The `System V Interface Definition'.  The covers
   of the first editions were an amazingly nauseating shade of
   off-lavender.  See also {{book titles}}.

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}.