In {object-oriented programming} sending a message to an
	{object} (to invoke a {method}) is equivalent to calling a
	{procedure} in traditional programming languages, except that
	the actual code executed may only be selected at run time
	depending on the {class} of the object.  Thus, in response to
	the message "drawSelf", the method code invoked would be
	different if the target object were a circle or a square.

	(1995-02-16)

<operating system, programming> The process of carrying out
	the {instructions} in a computer program by a computer.

	See also {dry run}.

	(1996-05-13)

1. {application program}.

	2. {function application}.

1. <language> {Synthesizer Specification Language}.

	2. <language> {Syntax/Semantic Language} (S/SL).

	3. <networking, World-Wide Web> {Secure Sockets Layer}.

	(1996-09-08)

<library, networking> {Unix} socket library routine to connect
	a socket that has been created on the local hosts to one at a
	specified socket address on the remote host.

	{Unix manual pages}: connect(2), accept(2).

	(1995-03-21)

(FTP) A {client-server} protocol which allows a user on one
	computer to transfer files to and from another computer over a
	{TCP/IP} network.  Also the client program the user executes
	to transfer files.  It is defined in {STD 9}, {RFC 959}.

	See also {anonymous FTP}, {FSP}, {TFTP}.

	{Unix manual page}: ftp(1).

	(1994-12-01)

<programming> A computer system or process that requests a
	service of another computer system or process (a "{server}")
	using some kind of {protocol} and accepts the server's
	responses.  A client is part of a {client-server} software
	architecture.

	For example, a {workstation} requesting the contents of a file
	from a {file server} is a client of the file server.

	(1997-10-27)

1. A program which provides some service to other ({client})
	programs.  The connection between client and server is
	normally by means of {message passing}, often over a
	{network}, and uses some {protocol} to encode the client's
	requests and the server's responses.  The server may run
	continuously (as a {daemon}), waiting for requests to arrive
	or it may be invoked by some higher level daemon which
	controls a number of specific servers ({inetd} on {Unix}).

	There are many servers associated with the {Internet}, such as
	those for {HTTP}, {Network File System}, {Network Information
	Service} (NIS), {Domain Name System} (DNS), {FTP}, {news},
	{finger}, {Network Time Protocol}.  On Unix, a long list can
	be found in /etc/services or in the {NIS} database "services".
	See {client-server}.

	2. A computer which provides some service for other computers
	connected to it via a network.  The most common example is a
	{file server} which has a local disk and services requests
	from remote clients to read and write files on that disk,
	often using {Sun}'s {Network File System} (NFS) {protocol} or
	{Novell Netware} on {PCs}.  Another common example is a {web
	server}.

	[{Jargon File}]

	(2003-12-29)

<jargon> To transfer data from one computer to another.
	Downloading usually refers to transfer from a larger "host"
	system (especially a {server} or {mainframe}) to a smaller
	"client" system, especially a {microcomputer} or specialised
	peripheral, and "{upload}" usually means from small to large.

	Others hold that, technically, download means "receive" and
	upload means "send", irrespective of the size of the systems
	involved.

	Note that in communications between ground and space,
	space-to-earth transmission is always "down" and the reverse
	"up", regardless of size.  So far the in-space machines have
	invariably been smaller; thus the upload/download distinction
	has been reversed from its usual sense.

	[{Jargon File}]

	(2003-11-04)

1. To copy {data} (often {program} {code} to be {run}) into
	{memory}, possibly {parsing} it somehow in the process.
	E.g. "{WordPerfect} can't load this {RTF} file - are you sure
	it didn't get corrupted in the {download}?"  Opposite of
	{save}.

	2. The degree to which a computer, {network}, or other
	resource is used, sometimes expressed as a percentage of the
	maximum available.  E.g. "What kind of CPU load does that
	program give?", "The network's constantly running at 100%
	load".  Sometimes used, by extension, to mean "to increase the
	level of use of a resource".  E.g. "Loading a spreadsheet
	really loads the CPU".  See also: {load balancing}.

	3. To {install} a piece of {software} onto a system.
	E.g. "The computer guy is gonna come load Excel on my laptop
	for me".  This usage is widely considered to be incorrect.

	(2002-07-02)

<file system> A node in a hierarchical {file system} which
	contains zero or more other nodes - generally, {files} or
	other directories.

	Compare {folder}.

	(1997-04-10)

1. <unit, text> (Sometimes abbreviated "pt") The unit of
	length used in {typography} to specify text character height,
	{rule} width, and other small measurements.

	There are six slightly different definitions: {Truchet point},
	{Didot point}, {ATA point}, {TeX point}, {Postscript point},
	and {IN point}.

	In Europe, the most commonly used is Didot and in the US, the
	formerly standard ATA point has essentially been replaced by
	the PostScript point due to the demise of traditional
	typesetting systems and rise of desktop computer based systems
	running software such as {QuarkXPress}, {Adobe InDesign} and
	{Adobe Pagemaker}.

	There are 20 {twips} in a point and 12 points in a {pica}
	(known as a "Cicero" in the Didot system).

	{Different point systems
	(http://www.vakcer.com/oberon/dtp/fonts/point.htm)}.

	(2004-12-23)

	2. <hardware> To move a {pointing device} so that the
	on-screen pointer is positioned over a certain object on the
	screen such as a {button} in a {graphical user interface}.  In
	most {window systems} it is then necessary to {click} a
	(physical) button on the pointing device to activate or select
	the object.  In some systems, just pointing to an object is
	known as "mouse-over" {event} which may cause some help text
	(called a "tool tip" in {Windows}) to be displayed.

	(2001-05-21)

1. Predetermined hardware or software activity designed to
	establish or maintain two machines or programs in
	synchronisation.  Handshaking often concerns the exchange of
	messages or {packets} of data between two systems with limited
	{buffers}.  A simple handshaking {protocol} might only involve
	the receiver sending a message meaning "I received your last
	message and I am ready for you to send me another one."  A
	more complex handshaking {protocol} might allow the sender to
	ask the receiver if he is ready to receive or for the receiver
	to reply with a negative acknowledgement meaning "I did not
	receive your last message correctly, please resend it" (e.g. if
	the data was corrupted en route).

	{Hardware handshaking} uses voltage levels or pulses on wires
	to carry the handshaking signals whereas {software
	handshaking} uses data units (e.g. {ASCII} characters) carried
	by some underlying communication medium.

	{Flow control} in bit-serial data transmission such as
	{EIA-232} may use either hardware or software handshaking.

	2. The method used by two {modems} to establish contact with
	each other and to agreee on {baud rate}, {error correction}
	and {compression} {protocols}.

	3. The exchange of predetermined signals between agents
	connected by a communications channel to assure each that it
	is connected to the other (and not to an imposter).  This may
	also include the use of passwords and codes by an operator.

	[{Jargon File}]

	(1995-01-13)

<company> (IBM) The best known American computer manufacturer,
	founded by Thomas J. Watson (born 1874-02-17), known as "Big
	Blue" after the colour of its logo.  IBM makes everything from
	{mainframes} to {personal computers} (PCs) and has been
	immensely successful in selling them, chiefly to business.  It
	has often been said that "Nobody has ever been sacked for
	buying IBM".

	The {IBM PC} in its various versions has been so successful
	that unqualified reference to a "PC" almost certainly means a
	PC from IBM, or one of the many brands of {clone} produced by
	other manufacturers to cash in on IBM's original success.

	Alternative expansions of "IBM" such as Inferior But
	Marketable; It's Better Manually; Insidious Black Magic; It's
	Been Malfunctioning; Incontinent Bowel Movement, illustrate
	the considerable antipathy most hackers have long felt toward
	the "industry leader" (see {fear and loathing}).

	Quarterly sales $15351M, profits $689M (Aug 1994).

	{Home (http://www.ibm.com/)}.

	(1999-04-07)

<standard> (RFC) One of a series, begun in 1969, of numbered
	{Internet} informational documents and {standards} widely
	followed by commercial software and {freeware} in the
	{Internet} and {Unix} communities.  Few RFCs are standards but
	all Internet standards are recorded in RFCs.  Perhaps the
	single most influential RFC has been {RFC 822}, the Internet
	{electronic mail} format standard.

	The RFCs are unusual in that they are floated by technical
	experts acting on their own initiative and reviewed by the
	Internet at large, rather than formally promulgated through an
	institution such as {ANSI}.  For this reason, they remain
	known as RFCs even once adopted as standards.

	The RFC tradition of pragmatic, experience-driven,
	after-the-fact standard writing done by individuals or small
	working groups has important advantages over the more formal,
	committee-driven process typical of {ANSI} or {ISO}.

	Emblematic of some of these advantages is the existence of a
	flourishing tradition of "joke" RFCs; usually at least one a
	year is published, usually on April 1st.  Well-known joke RFCs
	have included 527 ("ARPAWOCKY", R. Merryman, UCSD; 22 June
	1973), 748 ("Telnet Randomly-Lose Option", Mark R. Crispin; 1
	April 1978), and 1149 ("A Standard for the Transmission of IP
	Datagrams on Avian Carriers", D. Waitzman, BBN STC; 1 April
	1990).  The first was a Lewis Carroll pastiche; the second a
	parody of the {TCP/IP} documentation style, and the third a
	deadpan skewering of standards-document legalese, describing
	protocols for transmitting Internet data packets by carrier
	pigeon.

	The RFCs are most remarkable for how well they work - they
	manage to have neither the ambiguities that are usually rife
	in informal specifications, nor the committee-perpetrated
	{misfeatures} that often haunt formal standards, and they
	define a network that has grown to truly worldwide
	proportions.

	{rfc.net (http://www.rfc.net/)}.
	{W3
	(http://www.w3.org/hypertext/DataSources/Archives/RFC_sites.html)}.
	{JANET UK FTP (ftp://nic.ja.net/pub/newsfiles/JIPS/rfc)}.
	{Imperial College, UK FTP (ftp://src.doc.ic.ac.uk/rfc/)}.
	{Nexor UK (http://www.nexor.com/public/rfc/index/rfc.html)}.
	{Ohio State U
	(http://www.cis.ohio-state.edu/hypertext/faq/usenet/top.html)}.

	See also {For Your Information}, {STD}.

	(1997-11-10)

<networking, protocol> (TLS) A {protocol} designed to allow
	{client/server} applications to communicate over the
	{Internet} without {eavesdropping}, {tampering}, or {message
	forgery}.

	TLS is defined in {RFC 2246}.

	(2003-10-03)

<protocol> (HTTP) The {client-server} {TCP/IP} {protocol} used
	on the {World-Wide Web} for the exchange of {HTML} documents.
	It conventionally uses {port} 80.

	Current version: HTTP 1.1, defined in {RFC 2068}, as of May
	1997.

	See also {Uniform Resource Locator}.

	(1994-10-27)

<data, data processing, jargon> /day't*/ (Or "raw data")
	Numbers, {characters}, {images}, or other method of recording,
	in a form which can be assessed by a human or (especially)
	input into a {computer}, stored and {processed} there, or
	transmitted on some {digital channel}.  Computers nearly
	always represent data in {binary}.

	Data on its own has no meaning, only when interpreted by some
	kind of {data processing system} does it take on meaning and
	become {information}.

	People or computers can find patterns in data to perceive
	information, and information can be used to enhance
	{knowledge}.  Since knowledge is prerequisite to wisdom, we
	always want more data and information.  But, as modern
	societies verge on {information overload}, we especially need
	better ways to find patterns.

	1234567.89 is data.

	"Your bank balance has jumped 8087% to $1234567.89" is
	information.

	"Nobody owes me that much money" is knowledge.

	"I'd better talk to the bank before I spend it, because of
	what has happened to other people" is wisdom.

	(1999-04-30)

<electronics> The quantity of {charge} per unit time, measured
	in Amperes (Amps, A).  By historical convention, the sign of
	current is positive for currents flowing from positive to
	negative {potential}, but experience indicates that electrons
	are negatively charged and flow in the opposite direction.

	(1995-10-05)

<data> A data structure holding many values, possibly of
	different types, which is usually accessed sequentially,
	working from the head to the end of the tail - an "ordered
	list".  This contrasts with a (one-dimensional) {array}, any
	element of which can be accessed equally quickly.

	Lists are often stored using a cell and pointer arrangement
	where each value is stored in a cell along with an associated
	pointer to the next cell.  A special pointer, e.g. zero, marks
	the end of the list.  This is known as a (singly) "linked
	list".  A doubly linked list has pointers from each cell to
	both next and previous cells.

	An unordered list is a {set}.

	(1998-11-12)

<operating system> A character string which tells a program to
	perform a specific action.  Most commands take {arguments}
	which either modify the action performed or supply it with
	input.  Commands may be typed by the user or read from a file
	by a {command interpreter}.  It is also common to refer to
	menu items as commands.

	(1997-06-21)

<standard> Standards are necessary for {interworking},
	{portability}, and {reusability}.  They may be {de facto
	standards} for various communities, or officially recognised
	national or international standards.

	{Andrew Tanenbaum}, in his Computer Networks book, once said,
	"The nice thing about standards is that there are so many of
	them to choose from", a reference to the fact that competing
	standards become a source of confusion, division,
	obsolescence, and duplication of effort instead of an
	enhancement to the usefulness of products.

	Some bodies concerned in one way or another with computing
	standards are {IAB} ({RFC} and {STD}), {ISO}, {ANSI}, {DoD},
	{ECMA}, {IEEE}, {IETF}, {OSF}, {W3C}.

	(1999-07-06)

<character> (Or "ctrl", "^") One (or a pair) of {modifier
	keys} found on all modern {keyboards}.  If the control key is
	held down while pressing and releasing certain other keys then
	a "{control character}" is generated, e.g. holding control and
	hitting "A" generates control-A ({ASCII} code 1).  The ASCII
	code for the control character is generally 64 less than that
	for the unmodified character.

	The control key does not generate any character on its own but
	most modern keyboards and {operating systems} allow a program
	to tell whether each of the individual keys on the keyboard
	(including modifier keys) is pressed at any time.

	Control characters mostly have some kind of "non-printing"
	effect on the output such as ringing the bell (Control-G) or
	advancing to the next line (Control-J).  Most have alternative
	names suggesting these functions (Bell, Line Feed, etc.).

	See {ASCII character table}.

	(1997-07-10)

<chat> (Or "chat room", "room", depending on the system in
	question) The basic unit of group discussion in {chat} systems
	like {IRC}.  Once one joins a channel, everything one types is
	read by others on that channel.  Channels can either be named
	with numbers or with strings that begin with a "#" sign and
	can have topic descriptions (which are generally irrelevant to
	the actual subject of discussion).

	Some notable channels are "#initgame", "#hottub" and
	"#report".  At times of international crisis, "#report" has
	hundreds of members, some of whom take turns listening to
	various news services and typing in summaries of the news, or
	in some cases, giving first-hand accounts of the action
	(e.g. Scud missile attacks in Tel Aviv during the Gulf War in
	1991).

	[{Jargon File}]

	(1998-01-25)

<programming, operating system> The predefined input/output
	channels which every {Unix} process is initialised with.
	Standard input is by default from the terminal, and standard
	output and standard error are to the terminal.  Each of these
	channels (controlled via a {file descriptor} 0, 1, or 2 -
	stdin, stdout, stderr) can be redirected to a file, another
	device or a {pipe} connecting its process to another process.
	The process is normally unaware of such {I/O redirection},
	thus simplifying prototyping of combinations of commands.

	The {C} programming language library includes routines to
	perform basic operations on standard I/O.  Examples are
	"printf", allowing text to be sent to standard output, and
	"scanf", allowing the program to read from standard input.

	(1996-06-07)

<cryptography, company> (The initials of the authors)

	1. {RSA Data Security, Inc.}

	2. Their {cryptography} systems, especially {RSA encryption}.

	The RSA {algorithm} was first described in the paper:

	[R. Rivest, A. Shamir, L. Adleman, "A Method for Obtaining
	Digital Signatures and Public-key Cryptosystems". CACM 21,2;
	1978]

	(1995-03-21)

<language> A line-oriented {Smalltalk} for {PC}'s, produced by
	Digitalk ca 1985.  Methods was the predecessor of
	{Smalltalk/V}.

	(1995-04-16)

<programming> (OID) Generally an implementation-specific
	{integer} or {pointer} that uniquely identifies an {object}.

	(1999-07-10)

1. Executable code, especially a "pure code" portion shared
	between multiple instances of a program running in a
	{multitasking} {operating system}.

	Compare {English}.

	2. Textual material in the mainstream sense; data in ordinary
	{ASCII} or {EBCDIC} representation (see {flat ASCII}).  "Those
	are text files; you can review them using the editor."

	These two contradictory senses confuse hackers too.

	[{Jargon File}]

	(1995-03-16)

<software> A program by {Richard Stallman} to discover
	properties of the current {platform} and to set up {make} to
	compile and install {gcc}.

	{Cygnus configure} was a similar system developed by
	K. Richard Pixley in collaboration with Richard Stallman.
	In 1994, David MacKenzie and others modified {autoconf} to
	incorporate all the features of Cygnus configure and many
	{GNU} programs, including gcc now use autoconf.

	{Metaconfig} is a similar program used in building {Perl}.

	{(http://www.airs.com/ian/configure)}.

	(2005-04-15)