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WAN. See wide area network.

WAN links. Communications connections between groups of computers that are spread across a large geographical distance. Modem connections, T1 lines, and satellite hookups are some common examples. See also wide area network.

water mark. A limit value used in flow control. Each queue has a high-water mark and a low-water mark. The high-water mark value indicates the upper limit related to the number of bytes contained on the queue. When the characters in a queue reach the high-water mark, STREAMS causes another queue that attempts to send a message to this queue to become blocked. When the characters in this queue are reduced to the low-water mark value, the other queue is unblocked by STREAMS.

Web-based System Manager. A graphical user interface (GUI) tool for managing the operating system. Based on the OO (Object Oriented) model, Web-based System Manager enables users to perform administration tasks by manipulating icons representing objects in the system, as an alternative to learning and remembering complex commands.

well-known host name. A conventional name associated with an Internet Protocol address on a particular network (for example, the nameserver and timeserver servers).

well-known port. A conventional port assignment used by hosts that support the same protocols, whether or not the hosts are on the same network. Synonymous with contact port.

while statement. A C language looping statement that contains the keyword while followed by an expression in parentheses (the condition) and a statement (the action).

white space. Space characters, tab characters, and new-line characters.

wide area network (WAN). A network that provides data communication capability in geographic areas larger than those serviced by local area networks. A network that includes computers spread across a large geographical distance, usually involving several cities, states, or countries.

wide band channel. A communications channel that has a greater bandwidth than a voice channel; therefore, it is capable of transmitting data at high speeds. Synonym for broadband channel.

widening. An expansion of the size of a value (for example, short to int) by padding bits located to the left of the value with a copy of the sign bit.

widget. (1.) The fundamental data type of the Enhanced X-Windows Toolkit. (2.) An object providing a user-interface abstraction; for example, Scrollbar widget. It is the combination of an Enhanced X-Windows (or subwindow) and its associated semantics. Logically, it is a rectangle with associated input and output semantics, although some can be input-only or output-only. Each widget belongs to one widget class. A widget implements procedures through its widget class structure. See also composite widget, core widget, primitive widget, and shell widget. (3.) A widget is a graphic device capable of receiving input from the keyboard and the mouse and communicating with an application or another widget by means of a callback. Every widget is a member of only one class and always has a window associated with it.

widget class. The general group that a specific widget belongs to, otherwise known as the widget type. Physically, it is a pointer to a structure. Synonymous with widget type. See also class.

widget gravity. Synonym for window gravity.

widget hierarchy. Synonymous with widget tree.

widget ID. A unique identification number associated with each widget instantiated in an interface.

widget instance. A specific widget object as opposed to a general widget class. It is composed of a data structure containing instance-specific values and another data structure containing information applicable to all widgets of that class. See also instance.

widget menu. A menu that allows the user to perform any number of actions, such as cutting, copying, and pasting, to selected widgets.

widget programmer. A programmer who adds new widgets to the Enhanced X-Windows (or other) Toolkit.

widget record. A collection of related data objects, such as variables and parameters, associated with any given widget. See also instance record, record, class record, and superclass.

widget tree. (1.) The symbolic structure for Enhanced X-Windows Toolkit code. The basic element is a widget class. See also leaves, intermediate nodes, and root. (2.) A widget tree is a hierarchy of widgets within a specific client application. The Shell widget is the root of the widget tree. Widgets with no children of any kind are leaves of the tree. Synonymous with widget hierarchy.

widget type. Synonym for widget class.

widget visibility. Contrast with obscure and occlude.

wildcard. Special characters such as * (asterisk) or ? (question mark) that can be used to match one or more characters. Synonymous with pattern-matching character.

window. (1.) In AIXwindows, rectangular area of the screen that can be moved about, placed on top of or pulled under other windows, or iconized by the user. (2.) In GL, all drawing inside the window is done by the GL process that created that window, and is totally under the control of that process. However, the drawing of the window borders together with the window placement/iconization, is under the control of the window manager; for example, the AIXwindows Window Manager. For most simple GL programs, the viewport and screenmask are set to the same size as the window. Do not confuse an AIXwindows subroutine with the GL window subroutine, which defines a frustum in world space. See also clipping and current window. (3.) In curses and extended curses, the internal representation of what a portion of the display may look like at some point in time. Windows can be any size, from the entire display screen to a single character. (4.) In data communications, the number of data packets a DTE or DCE can send across a logical channel before waiting for authorization to send another data packet. The window is the main mechanism of pacing, or flow control, of packets. See also frame window and packet window. (5.) In the INed editor, an area within the display screen that can be subdivided into a collection of contiguous panes used to present data to the user.

window gravity. The attraction of a subwindow to some part of its parent. Window gravity causes subwindows to be automatically repositioned, relative to an edge, corner, or center of a window when resized. Synonymous with widget gravity. See also gravity.

window icon. In CDE, a minimized window.

window ID. A unique identification number associated with each newly opened window in an AIXwindows or Enhanced X-Windows environment.

window manager. In Common Desktop Environment, the program that displays and controls windows on your screen. Software that manages the multiple windows associated with AIXwindows and Enhanced X-Windows. In a graphics environment, the client that manipulates windows on a screen and provides much of the user interface. See also mwm.

Window Manager. In CDE, the software application that provides users with the capability to manipulate windows on the workspace; for example, opening, resizing, moving, and closing windows.

Window menu. In CDE, the menu displayed by choosing the Window menu button. The menu provides choices that manipulate the location or size of the window, such as Move, Size, Minimize, and Maximize.

Window menu button. In CDE, the control at the upper left corner of a window, next to the title bar. Choosing it displays the Window menu.

wire frame. A graphics surface-drawing technique in which the edges and contours of a primitive are represented by simple lines.

with clause. For Ada programming, see compilation unit.

word. (1.) A contiguous series of 32 bits (four bytes) in storage, addressable as a unit. The address of the first byte of a word is evenly divisible by four. Synonymous with fullword, machine word, and computer word. Contrast with halfword. (2.) A character string considered as a unit for a given purpose.

word wrap. In word processing, a feature that automatically moves text to the next line if the text does not fit within the margins.

work area. In CDE, the part of a window where controls and text appear.

work file. A file used for temporary storage of data being processed.

working directory. Synonym for current directory.

working segment. A segment whose pages are backed by slots in the disk paging space rather than by a permanent location on disk.

working set. The parts of a program's executable code, data areas, or both that are being used intensively and are therefore important to keep in the fastest possible type of storage. Thus a program's instruction cache working set is the set of program cache lines that need to be kept in the instruction cache if the program is to run at maximum speed.

workload. A sequence of requests, such as commands, I/O operations, and subroutine-library calls, that constitute the work being done by a system. The term normally refers to a workload that has been captured in such a way as to be repeatable (via shell scripts, remote terminal emulators), so that it can be used to measure the performance effect of changes to the system.

workload concurrency. The degree to which the system approaches the ideal of always having as many dispatchable threads as there are processors.

workspace. (1.) In XDS/XOM, a space in which OM objects of certain OM classes can be created, together with an implementation of the object management functions that supports those OM classes. (2.) In CDE, the current screen display, the icons and windows it contains, and the unoccupied screen area where icons can be placed.

workspace background. In CDE, the portion of the display not covered by windows or icons.

workspace icon. In CDE, an icon that has been copied from File Manager to the workspace.

workspace interface. The interface as realized, for the dispatcher's benefit, by each workspace individually.

Workspace Manager. In CDE, the software application that controls the size, placement, and operation of windows within multiple workspaces.

Workspace menu. In CDE, the menu displayed by pointing at an unoccupied area of the workspace and clicking button 3 on the mouse.

workspace object. In CDE, an object that resides in a workspace, rather than inside a viewer in a window. Workspace objects include windows, icons (minimized windows), and objects that have been dragged from File Manager and Application Manager and dropped on a workspace.

workspace switch. In CDE, a control that enables you to select one workspace from among several workspaces.

workspace switch area. In CDE, the rectangular area in the center of the Front Panel that contains the workspace switches, the Lock control, the Exit button, and the busy light.

workstation. (1.) A configuration of input/output equipment at which an operator works. (2.) A terminal or microcomputer, usually one that is connected to a mainframe or to a network, at which a user can perform applications. See also terminal.

world coordinates. In GL, the user-defined coordinate system in which an image is described. Modeling commands are used to position primitives in world space. Viewing and projection transformations define the mapping of the world space to screen space. Synonymous with world space. See also modeling coordinates, eye coordinates, primitive coordinates, screen coordinates, viewing matrxi, and transformation.

world space. Synonym for world coordinates.

wrap around. (1.) The movement of the point of reference in a file from the end of one line to the beginning of the next, or from one end of a file to the other. (2.) In display-based word processing equipment, the automatic disposition of a printable line of text onto two or more display lines, necessitated by the horizontal limits of the display. (3.) The continuation of an operation from the maximum addressable location in storage to the first addressable location. (4.) The continuation of register addresses from the highest register address to the lowest.

wrap test. A test that checks attachment or controller circuitry without testing the device itself by returning the output of the device as input.

Wrap To Fit. In CDE, in Text Editor, this setting controls whether lines are automatically wrapped to fit the window width as you enter text. If set, lines wrap at the edge of the window. If not set, you must press Return to end the line.

write-ahead logging. A logging mechanism wherein all of the log records associated with a transaction are written to the log before the transaction actually commits. This guarantees that those log records will be present in the log and can therefore be used to restore recoverable data to a correct state should the system fail at the exact time of a transaction commit.

write back cache. In Enhanced X-Windows, GCs cached by the library to allow merging independent change requests into one protocol request. See also cache.

write queue. The message queue in a module or driver containing messages moving downstream. Associated with output from a user process.

write verification. A mode in which the system automatically performs a read operation after performing a write operation. It then compares the data to make sure they are the same.

writemask. A set of 8 or 12 bits (depending on the frame buffer configuration), one bit for each bitplane of the frame buffer. During any drawing operation, only those planes enabled by a 1 (one) in the bit mask can be altered. Planes set to 0 (zero) are marked read only.

writers. See readers and writers.

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