Glossary P
package
In Visual C++, a dynamic-link library that extends the development environment.
In Java, a group of classes declared with the package keyword. Classes are generally packaged together when they are related in a significant way. In Java, the default level of data access is at the package level. In C++, the default level of data access is at the class level.
packaged function
A function created by the compiler when function-level linking is enabled. A packaged function is visible to the linker in the form of a COMDAT record placed in the object (.OBJ) file by the compiler. Functions that are not packaged can be linked only at the object level.
Packet Internet Groper
A program useful in testing and debugging LAN/WAN troubles. It sends out a packet and expects a specified host to respond back in a specified time frame.
palette
An array of colors currently available on a device.
A modeless secondary window that displays a toolbar or another set of controls.
pane
One of the separate areas in a split window, or a rectangular area of the status bar that can be used to display information.
PAP
In ISDN, a type of authentication accomplished by sending user ID/password pairs between two devices.
parameter
Or argument. A value or an expression used with an operator or passed to a subprogram (subroutine, procedure, or function). The program then carries out operations using the arguments. Parameters are also used with templates; such parameters can include classes as well as values and expressions.
parameter data member
In recordsets, a data member that accepts parameter information at run time. Parameter data members can be used in a query to select records from a database based on the value of the parameter obtained or calculated at run time. See also field data member.
parameter passing
The sending of variables as parameters (arguments) to a subroutine, procedure, or function. You can pass parameters by value or by reference. Passing by value copies the variable’s value into the subroutine’s formal argument. Passing by reference copies the variable’s memory address into the subroutine’s formal argument. In C++, parameters may be passed by value or by reference. In C, all parameters are passed by value, except for arrays, which are translated into the address of the first member and reference of type, as in **int&**ri. However, you can force a pass by reference by using pointers or references. In Java, parameter passing is by value only for simple types, by reference only for instances.
parent process
In a multitasking environment, a process that initiates one or more processes, called "child processes." The parent process defines the environment for child processes. The parent process can suspend or complete its own processing while the child processes continue operating.
parent window
A window that generates one or more child windows.
parse map
Code that allows a CHttpServer-derived object in MFC to map client requests to its member functions. MFC provides parse map macros to help map form variables on a Web page to parameters in your function.
parser
The part of a compiler, interpreter, or other translator that accepts tokens from the lexical analyzer and attaches semantics to those tokens.
Pascal calling convention
A calling convention that pushes arguments onto the stack in the order in which they appear in the function call (from left to right). The Pascal calling convention requires that the called routine remove arguments from the stack.
Password Authentication Protocol
In ISDN, a type of authentication accomplished by sending user ID/password pairs between two devices.
path bracket
One or more graphics device interface (GDI) functions embedded between a BeginPath and an EndPath function. (The BeginPath function defines the start of the bracket; the EndPath function defines the end.)
pen
In graphics applications, a drawing object used to draw lines and borders.
percent position
In DAO, the position of a record in a recordset, based on a percentage of the total numbers of records. For example, a record with a position of 50% lies halfway into the recordset.
PERL
A general-purpose scripting language used mainly for server-side HTML programming. It is freely available on a wide variety of platforms.
permanent storage
A disk medium, such as a hard disk or floppy disk.
A place to store data, such as a file or database.
In the Visual C++ documentation, a variable declared with the static storage-class specifier.
persistent
Lasting between program sessions, or renewed when a new program session is begun.
pessimistic locking
A recordset locking strategy in which a page is locked once a user begins editing a record on that page. While the page is locked, no other user can change a record on that page. The page remains locked until records are updated or the editing is canceled. See also optimistic locking.
physical brush
A bitmap that Windows uses to paint the interior of filled shapes. A physical brush is a device driver's approximation of a logical brush.
physical device
The fourth and final coordinate space for most graphics device interface (GDI) drawing operations. (The Win32 API uses four coordinate spaces: world, page, device, and physical device.) The points in this physical device coordinate space can correspond to the desktop, a client area, or a page of printer paper.
Hardware such as a modem or printer to which data can be written.
physical font
A font stored internally on a device or whose resources have been loaded into the operating system. See also logical font.
PING
A program useful in testing and debugging LAN/WAN troubles. It sends out a packet and expects a specified host to respond back in a specified time frame.
pipe
A communication conduit with two ends. A process with a handle to one end can communicate through a pipe with a process having a handle to the other end. Pipes can be one way (where one end is read-only and the other end is write-only) or two way (where both ends of the pipe can be used for reading or writing). The Win32 application programming interface (API) provides both anonymous (unnamed) pipes and named pipes.
An IDL type constructor that supports transmission of an open-ended stream of data between client and server applications.
pixel
The smallest addressable picture element (that is, a single dot) on a display screen or printed page. See also raster.
placeholder
A symbol in an expression indicating information to be supplied. For example, in the following SQL statement
SELECT CourseID, CourseTitle FROM Course WHERE CourseID = ?
the question mark (?) is a placeholder for a parameter value supplied at run time.
platform
The hardware and operating system that support an application. "Platform" sometimes refers to the hardware alone, as in the Intel x86 platform.
point
In typography, a unit of measurement for type (1 point equals approximately 1/72 inch).
Point-to-Point Protocol
An advanced serial packet protocol, similar to but an improvement on SLIP, commonly used for dial-up connections. PPP is an official Internet protocol; SLIP is not.
pointer
A data type that can contain the address of another data type such as a variable, or of a function or class.
A graphic image displayed on the screen that indicates the location of a pointing device (sometimes called a "cursor").
polygon-filling mode
In graphics, an algorithm that determines the parts of a region that can be filled, painted, inverted, or clipped.
polymorphism
In C++, the concept of a single interface for multiple functions. For example, different classes can each contain a function called print that prints data in a format appropriate for objects of that class. The compiler selects the appropriate print function for each call to print. See also virtual function.
pop-up menu
A menu that is hidden until the user performs an action (such as clicking the right mouse button) that causes Windows to display the menu. The pop-up menu contains commands that are relevant to the selection or the active window. See also drop-down menu.
pop-up window
An immovable, nonsizable window that remains on the screen until the user dismisses it. Pop-up windows typically contain definitions of terms or other parenthetical information. Good uses for pop-up windows include illustrations, examples, notes, tips, and lists of keyboard shortcuts.
portable code
Code that can be compiled with little or no change to run on more than one platform.
Portable Operating System for Unix
An IEEE standard that defines the language interface between the UNIX operating system and application programs through a minimal set of supported functions.
POSIX
An IEEE standard that defines the language interface between the UNIX operating system and application programs through a minimal set of supported functions.
postfix notation
Placing of operators after operands, as in xy**+z***. Compare prefix notation, infix notation.
PPP
An advanced serial packet protocol, similar to but an improvement on SLIP, commonly used for dial-up connections. PPP is an official Internet protocol; SLIP is not.
Practical Extraction and Reporting Language
A general-purpose scripting language used mainly for server-side HTML programming. It is freely available on a wide variety of platforms.
pragma
An instruction to the compiler to perform a given action at compile time. For example, the pragma
#pragma pack( [n] )
specifies packing alignment for structure and union members.
precompiled header directive
A statement in a source or include file specifying where precompilation should stop.
precompiled header file
A file containing compiled code for a portion of a project. Subsequent builds combine this file with the uncompiled code, thus shortening the overall compile time. The default filename extension for a precompiled header file is .PCH.
predefined macro
A macro recognized by the compiler that takes no arguments and cannot be redefined. In most cases, the value of a predefined macro must be constant throughout compilation. For example, the ANSI prefined macro __TIME__ expands to the most recent compilation time of the current source file, expressed as a string literal of the form hh:mm:ss.
predefined query
Or stored procedure. In SQL, a set of one or more SQL statements stored in a data source, available to be called from an application as needed. Predefined queries reduce the overhead of repeatedly specifying the same selection criteria.
prefix character
In Windows text controls, the ampersand (&) character used to define the next character in the string as the mnemonic access key for the control. The ampersand is a directive to underscore the next character in the interface. A two-ampersand (&&) mnemonic-prefix character is a directive to print a single ampersand in the interface.
prefix notation
Placing of operators before operands, as in ***+**xyz. Compare infix notation, postfix notation.
preprocessor
A text processor that manipulates the text of a source file as part of the first phase of translation. The preprocessor does not parse the source text, but it does break it up into tokens for the purpose of locating macro calls. Although the compiler ordinarily invokes the preprocessor in its first pass, the preprocessor can also be invoked separately to process text without compiling.
preprocessor directive
Or compiler directive. An instruction to the preprocessor to perform an action on source-program text before the compilation phase. For example, the directive #include "my_defs.h" instructs the preprocessor to include the contents of the file my_defs.h in the compilation unit.
presentation cache
In OLE, a container document's memory cache for the graphical representation of a linked or embedded object. Such a presentation is cached locally in the container document so it can be obtained without the expense of running the object's application. See also presentation data.
presentation data
In OLE, the graphical representation of a linked or embedded object.
presentation data
The data used by a container to display embedded or linked objects. See also native data.
primary key
In a database program, a field or group of fields that uniquely identify a record in a table. No two records in a table can have the same primary key value.
primary language
A language, such as English or Japanese, defined for a particular program. In some cases, a sublanguage is also specified. For example, English can be specified as the primary language and Canadian as the sublanguage. See also language identifier (ID).
primary thread
Or main thread. The initial thread of a process. When the primary thread terminates, so does the process. This primary thread is supplied to the operating system by the startup code in the form of a function address. Usually, it is the address of the main or WinMain function that is supplied.
primary token
An access token that is typically created only by the Windows NT executive layer. The primary token can be assigned to a process to represent the default security information for that process. See also access token, impersonation token, privilege, security identifier (SID).
primary verb
In OLE, the command that is executed when the user double-clicks an OLE item. For most types of OLE items, the primary verb is Edit, which launches the server that created the item. OLE items can support one or more verbs.
primary verb
The action associated with the most common or preferred operation users perform on an object. The primary verb is always defined as verb zero in the system registration database. An object's primary verb can be its default action.
print processor
A dynamic-link library that receives information from the print spooler and sends the interpreted information to the graphics engine (another Windows DLL), which converts print processor output into device driver function calls. The printer processes these commands when it prints the image.
private
In C++, describes a limited degree of access to class members, as specified using the private keyword. Access to the specified class member is restricted to member functions and friends of the member or class.
privilege
In Windows NT, a locally unique identifier (LUID) used to control access to an object or service more strictly than is typical with discretionary access control. A system manager uses privileges to control which users are able to manipulate system resources. An application uses privileges when it changes a system-wide resource, such as when it changes the system time or shuts down the system. See also access token, impersonation token, primary token, security identifier (SID).
process
An executing application that consists of a private virtual address space, code, data, and other operating-system resouces, such as files, pipes, and synchronization objects that are visible to the process. A process also contains one or more threads that run in the context of the process.
profiler
A development tool for analyzing the run-time behavior of programs. See also function profiling, line profiling.
profiler batch input file
In a profiling operation, a file that provides condensed information to the Visual C++ profiler (PROFILE). The PREP program generates a profiler batch input file the first time the profiler is run on a program. The default filename extension for profiler batch input files is .PBI. See also profiler batch output file, profiler batch text file.
profiler batch output file
An intermediate file generated by the Visual C++ profiler (PROFILE) and used to transfer information between profiling steps. See also profiler, profiler batch input file, profiler batch text file.
profiler batch text file
In a profiling operation, the file generated by the PREP program and used as input to the PLIST program to generate a human-readable profile of the source code. See also profiler, profiler batch input file, profiler batch output file.
program database file
A file used by the build tools to store information about a user's program. The program database file speeds linking during the debugging phase of development by keeping the debugging information separate from the object files.
progress bar control
In MFC, an application window that is used to indicate the progress of a lengthy operation. The control consists of a rectangle that is gradually filled, from left to right, with the system highlight color as an operation progresses.
prolog code
See prolog/epilog code sequence.
prolog/epilog code sequence
In Windows, a compiler-generated code sequence that executes on entry to a function. Prolog code allocates space on the stack, sets up addressing for the variables local to the function, and initializes registers so that variables passed to the function can be conveniently accessed. The epilog code, which executes on exit from the functions, frees this space, restores the original contents of the registers, and ensures that any return value from the function is available to the caller.
property
The data associated with an object.
property frame
The user interface mechanism that displays one or more property pages for a control. The OLE controls run-time system provides a standard implementation of a property frame that can be accessed by using a helper function. Customized implementations may be provided by the container. See also control, property page.
property page
A grouping of properties presented as a tabbed page of a property sheet.
property set
In OLE structured storage, information describing a document, stored in a standard format so that other applications can locate and read that information. For example, a document created with a word processor can have a property set describing the author, title, and keywords.
property set
A logically related group of properties that is associated with a persistently stored object. See also persistent property.
property sheet
A special kind of dialog box that is generally used to modify the attributes of some external object, such as the current selection in a view. A property sheet has three main parts: the containing dialog box, one or more property pages shown one at a time, and a tab at the top of each page that the user clicks to select that page. An example of a property sheet is the Project Settings dialog box in the Microsoft Visual C++.
protected
In C++, describes a limited degree of access to class members, as specified using the protected keyword. Access to the specified class member is restricted to member functions and friends of the class, as well as member functions of classes derived from the class.
protocol
In networking, a formal set of rules governing the format, timing, sequencing, and error control of exchanged messages on a data network; may also include facilities for managing a communications link and/or contention resolution; a protocol may be oriented toward data transfer over an interface, between two logical units directly connected, or on an end-to-end basis between two end users over a large and complex network
Rules and conventions of behavior for an action, such as argument passing, or an entity, such as the member functions of a class.
proxy
An interface-specific object that packages parameters for methods in preparation for a remote method call. A proxy runs in the address space of the sender and communicates with a corresponding stub in the receiver's address space. See also stub, marshaling, unmarshaling.
proxy DLL
A file that contains the code to support the use of a custom OLE interface by both client applications and object servers. Compiling an OLE interface with the MIDL compiler generates the files needed to build a proxy DLL.
proxy server
Or firewall. A way to protect your local area network from being accessed by others on the Internet. The proxy server acts as a security barrier between your internal network and the Internet, keeping others on the Internet from accessing confidential information on your internal network.
pseudotarget
In a makefile, a label used in place of a filename in a dependency line. The Microsoft Program Maintenance Utility (NMAKE) interprets the label as a file that does not exist and executes the commands in the dependency line. The following is an example of a pseudotarget, clean, that instructs NMAKE to remove all of the object files and the executable file from the project directory:
clean:
erase *.obj
erase *.exe
public
In C++, describes a broad degree of access to class members, as specified using the public keyword. The specified class member can be accessed by any function. See also private, protected.
punctuators
In C++, characters (!, %, ^, for example) that have syntactic and semantic meaning to the compiler but do not, of themselves, specify an operation that yields a value. Some punctuators, either alone or in combination, can also be C++ operators or be significant to the preprocessor.
pure virtual function
A virtual function set equal to 0, as in virtual void draw( ) = 0. You need not supply a definition for a pure virtual function. Abstract base classes contain at least one pure virtual function.