- P
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- pack
- To store data in a compact form in such a way that the original form can be recovered.
- pad
- To fill unused positions in a field with data, usually 0's, 1's, or blanks.
- page
- (1) In a virtual storage system, a fixed-length block that has a virtual address and is
transferred as a unit between real storage and auxiliary storage. I. A. (2) A
defined unit of space on a storage medium.
- parameter
- (1) In the C and C++ languages, an object declared as part of a function declaration or
definition that acquires a value on entry to the function, or an identifier following the
macro name in a function-like macro definition. X/Open. (2) Data passed
between programs or procedures. IBM.
- parameter declaration
- A description of a value that a function receives. A parameter declaration determines
the storage class and the data type of the value.
- parent class
- See base class.
- parent node
- In a tree structure, a node to which one or more other nodes are subordinate. See child node, root.
- parent process
- (1) The program that originates the creation of other processes by means of spawn or
exec function calls. (2) A process that creates other processes.
- parent window
- A window that provides its child windows with information on how and where to draw
themselves. The parent window defines the relationship that the child windows have with
other windows in the system. See child window, owner window.
- path name
- (1) A string that is used to identify a file. It has an optional beginning slash,
followed by zero or more file names separated by slashes. If the path name refers to a
directory, it may also have one or more trailing slashes. Multiple successive slashes are
considered to be the same as one slash. A path name that begins with two successive
slashes may be interpreted in an implementation-dependent manner, although more than two
leading slashes will be treated as a single slash. (2) A file name specifying all
directories leading to the file.
- pattern
- (1) A sequence of characters used either with regular expression notation or for path
name expansion, as a means of selecting various character strings or path names,
respectively. The syntaxes of the two patterns are similar, but not identical. X/Open.
(2) A recognizable shape, form, or configuration. IBM. (3) In computer
graphics, a combination of toned and untoned picture elements (pels) that make up an
image. (4) A regular expression that defines a search pattern. (5) In AIX graphics, a
16x16, 32x32, or 64x64 array of bits defining the texturing of polygons on the system
display. IBM.
- pause
- To temporarily halt the medium. The halted visual should remain displayed but no audio
should be played.
- pel
- See pixel.
- pipe
- To direct data so that the output from one process becomes the input to another process.
The standard output of one command can be connected to the standard input of another with
the pipe operator (|). Two commands connected in this way constitute a pipeline. IBM.
- pixel
- Picture element. The smallest area of a display screen capable of being addressed and
switched between visible and invisible states.
- pointer
- A variable that holds the address of a data object or function.
- pointer class
- A class that implements pointers.
- pointer to member
- An object used to identify members of a given type within objects of a given class.
- point size
- The size of a typeface, measured in points. The size refers to the height of the
letters. There are 72 points in an inch. See typeface.
- polymorphic function
- A function that can be applied to objects of more than one data type. C++ implements
polymorphic functions in two ways:
- Overloaded functions (calls are resolved at compile time)
- Virtual functions (calls are resolved at run time)
- polymorphism
- A characteristic of object-oriented programming that allows overloaded member functions
to be invoked on the basis of the run-time type of the object, not the declared type of
the object.
- port
- (1) To adapt an application for use with another operating system. Contrast with migrate. (2) To adapt an application for use with a different
compiler system or class library.
- portability
- The ability of a programming language to compile successfully on different operating
systems without requiring changes to the source code.
- portable character set
- The set of characters specified in POSIX 1003.2, section 2.4. See character set, Portable Operating System Interface.
- Portable Operating System
Interface (POSIX)
- (1) A set of operating system portable interface standards defined by the Institute of
Electrical and Electronic Engineers (IEEE). Now an ISO/IEC international standard (ISO/IEC
9945). (2) An IEEE 1003.1 standard that defines the language interface between application
programs and the UNIX operating system.
- positioning property
- The property of an element that is used to position the element in a collection. For
example, the value of a key may be used as the positioning property.
- POSIX
- See Portable Operating System
Interface.
- pragma
- A preprocessor directive that is not specified by the ISO standard. Pragmas often
control actions of the compiler and linker. A pragma always begins with a number sign (#).
- precedence
- The priority system for grouping different types of operators with their operands.
- precondition
- A condition that a function requires to be true when it is called.
- predefined function
- See built-in function.
- predefined macro
- One of several object-like macros supplied by IBM. See macro.
- predicate function
- A function that returns an IBoolean value of true or false. (IBoolean is
an integer-represented Boolean type.)
- preemptive multitasking
- The operating system's ability to interrupt a thread at almost any time and assign the
processor to a waiting thread. Multiple applications can thus run simultaneously, and a
single application cannot monopolize all of the system's resources. See multitasking.
- preparation
- Any activity that the source performs before rendering the data. For example, the drag
item may require that the source create a secondary thread where the source rendering
takes place. The system remains responsive to users so that they can do other tasks.
- preprocessor
- A phase of the compiler that examines the source program for preprocessor statements,
which are then executed, resulting in the alteration of the source program.
- preprocessor directive
- In C and C++, a statement that begins with the number sign (#) and contains instructions
that the preprocessor interprets.
- preroll
- To prepare a device to begin a playback or recording function with minimal delay.
- primary expression
- A literal, a name, or a name qualified by the scope resolution operator (::).
- primary part
- In a composite part, the representation of the part's base class on the free-form
surface, added when you first create the composite. For example, the primary part of an
IFrameWindow-based composite is the IFrameWindow* part instance.
- primary source file
- A source file defined for a build in the configuration file. Each primary source file is
processed only once during a compilation. See source file,
included source file. Contrast with secondary source file.
- primary thread
- The first thread created when a process is initialized. See thread.
- primitive
- See graphic primitive.
- primitive attribute
- A specifiable characteristic of a graphic primitive. See graphic attributes.
- priority queue
- A queue that has a priority assigned to its elements. When accessing elements, the
element with the highest priority is removed first. A priority queue has a largest-in,
first-out behavior. See queue.
- private
- Pertaining to a class member that is accessible only to member functions and friends of
that class. Contrast with protected, public.
- process
- (1) A collection of code, data, and other system resources, including at least one
thread of execution, that performs a data processing task. (2) A running application, its
address space, and its resources. (3) An instance of a running program. A Win32 process
owns a 4-GB address space containing the code and data for an application's executable
file; it does not execute anything. It also owns certain resources, such as files, dynamic
memory allocations, and threads.
- profiling
- The process of generating a statistical analysis of a program that shows processor time
and the percentage of program execution time used by each procedure in the program.
- program
- (1) One or more files containing a set of instructions conforming to a particular
programming language syntax. (2) A self-contained, executable module. Multiple copies of
the same program can be run in different processes.
- program group
- A window displaying a group of programs.
- program heap
- See free store.
- project
- (1) A container that groups related objects (tasks).
- property function
- A function that is used to determine whether the element it is applied to has a given
property or characteristic. A property function can be used, for example, to remove all
elements with a given property.
- protected
- Pertaining to a class member that is only accessible to member functions and friends of
that class, or to member functions and friends of classes derived from that class.
Contrast with private, public.
- prototype
- A function declaration or definition that includes both the return type of the function
and the types of its arguments. See function
prototype.
- public
- Pertaining to a class member that is accessible to all functions. Contrast with private, protected.
- pure virtual function
- A virtual function that has a function initializer of the form = 0;
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