: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 groundbreaking 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 {gronk}ed state. Syn. {120 reset}; see also {Big Red Switch}. Compare {Vulcan nerve pinch}, {bounce}, 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.