S
 
samples-per-second
The number of times per second that the audio card records data from the audio input. For example, 44 kiloHertz is CD quality, 22 kiloHertz is FM music quality, and 11 kiloHertz is voice quality.
SBCS
See single-byte character set.
scalar
An arithmetic object, or a pointer to an object of any type.
scan
To search backward and forward at high speed on a CD audio device.
scope
That part of a source program in which an object is defined and recognized.
scope operator (::)
An operator that defines the scope for the argument on the right. If the left argument is blank, the scope is global; if the left argument is a class name, the scope is within that class.
scroll increment
The number by which the current value of the circular slider is incremented or decremented when a user presses one of the circular slider control buttons.
secondary window
See child window.
section
A unit of code or data produced by the compiler. Sections do not have attributes. Contrast with segment.
seed
An initial value supplied to a random-number algorithm with which the algorithm can generate a unique sequence of pseudo-random numbers.
segment
A unit of code or data produced by the linker and existing only in an executable image of the program. The linker assigns attributes to sections, orders and groups them, and puts them into segments. Contrast with section.
semaphore
A synchronization kernel object used for counting resources. A semaphore offers a thread the ability to query the number of resources available. If one or more resources are available, the count of available resources is decremented. See critical section, kernel object, mutex, event.
sequence
A sequentially ordered flat collection.
sequential collection
An abstract class with the property of sequentially ordered elements.
server
(1) A functional unit that provides services to one or more clients over a network. (2) In the AIX operating system, an application program that usually runs in the background and is controlled by the system program controller.
shared library
On the AIX operating system, a library created by the ld command that contains at least one subroutine that can be used by multiple processes. Programs and subroutines are linked as before, but the code common to different subroutines is combined in one library file that can be loaded at run time and shared by many programs. A key to identify the shared library file is left in the header of each subroutine. A shared library file has the file extension .shr. See dynamic link library.
shell
A program that interprets sequences of text input as commands. It may operate on an input stream or it may interactively prompt and read commands from a terminal. X/Open.
siblings
All the children of the same parent (class, node, window) are said to be siblings of one another.
signal
(1) A condition that may be reported as a result of an error in program execution. For example, SIGFPE is the signal used to represent erroneous arithmetic operations such as a division by zero. See exception. (2) A mechanism by which a process may be notified of, or affected by, an event occurring in the system. Examples of such events include hardware exceptions and specific actions by processes. The term signal is also used to refer to the event itself. X/Open, I. (3) In AIX operating system operations, a method of interprocess communication that simulates software interrupts. IBM.
signaled
A state in which an object has been reactivated after the threads have been put to sleep. For example, if a thread in a parent process needs to wait for the child process to terminate, the parent's thread puts itself to sleep until the kernel object identifying the child process becomes signaled. See nonsignaled.
signal handler
A function to be called when the signal is reported.
silent mode
See unattended mode.
single-byte character set (SBCS)
A set of characters in which each character is represented by a one-byte code. Contrast with double-byte character set.
single-precision
Pertaining to the use of one computer word to represent a number, in accordance with the required precision. I.
slash
The character /, also known as solidus. This character is named <slash> in the portable character set.
SMPTE
Society for Motion Picture and TV Engineers.
SMPTE time code
A frame-numbering system developed by SMPTE that assigns a number to each frame of video. The 8-digit code is in the form HH:MM:SS:FF (hours, minutes, seconds, frame number). The numbers track elapsed hours, minutes, seconds, and frames from any chosen point.
Society for Motion Picture and TV Engineers
An organization that prepares standards and documentation for television production.
sorted
Segregated into groups according to specified criteria.
sorted bag
A sorted flat collection that allows duplicate elements. See key sorted bag.
sorted collection
(1) An abstract class with the property of sorted elements. (2) Any collection with sorted elements. See key sorted collection.
sorted map
A sorted flat collection with key and element equality.
sorted relation
A sorted flat collection that uses keys, has element equality, and allows duplicate elements.
sorted set
A sorted flat collection with element equality. See key sorted set.
source directory
A directory where a project's parts are physically stored. A project can have many source directories.
source file
A file that contains source statements for such items as high-level language programs and data description specifications. IBM. Contrast with object file.
source program
A set of instructions written in a programming language that must be translated to machine language before the program can be run. IBM.
source region
The smallest unit of code that can be recompiled and relinked during an incremental C++ build.
source type
Information associated with and used by an action. An action's list of source types specifies the kind of parts or files to which the action applies.
space character
The character defined in the portable character set as <space>. The space character is a member of the space character class of the current locale, but represents the single character, and not all of the possible members of the class. X/Open.
specifier
In declarations, an indication of storage class, fundamental data type, or other property of the object or function being declared.
sprite
A small graphic that can be moved independently around the screen, producing animated effects.
stack
A data structure in which new elements are added to and removed from the top of the structure. A stack is characterized by last-in, first-out (LIFO) behavior.
stack frame
The physical representation of the activation of a routine. The stack frame is allocated and freed on a LIFO (last-in, first-out) basis.
stack storage
See automatic storage.
standard error
An output stream usually intended to be used for diagnostic messages.
standard input
An input stream usually intended to be used for primary data input. X/Open. Standard input comes from the keyboard unless redirection or piping is used, in which case standard input can be from a file or the output from another command.
standard output
An output stream usually intended to be used for primary data output. X/Open. When programs are run interactively, standard output usually goes to the display unless redirection or piping is used, in which case standard output can go to a file or to another command.
stanza
In the AIX operating system, a group of lines in a file that together have a common function or define a part of the system. Stanzas are usually separated by blank lines or colons, and each stanza has a name. For example, the stanzas for the AIX compiler default configuration file specify information that the compiler uses when it is invoked.
statement
(1) A language costruct that represents a step in a sequence of actions or a set of declarations. (2) In a program or procedure, an instruction that ends with a semicolon (;), or several instructions that are surrounded by brace brackets ({}).
static
A keyword used for defining the scope and linkage of variables and functions. For internal variables, the variable has block scope and retains its value between function calls. For external values, the variable has file scope and retains its value within the source file. For class variables, the variable is shared by all objects of the class and retains its value within the entire program.
static library
A library linked with other modules when those modules are built. In IBM C/C++ Compilers, it has the file extension .lib. Contrast with dynamic link library.
static linking
Combining code and data at build time. Static linking increases the size of the executable file. Contrast with dynamic linking.
step backward
In multimedia applications, to move the medium backward one frame or segment at a time.
step forward
In multimedia applications, to move the medium forward one frame or segment at a time.
step frame
A function of devices such as digital video and videodisc players that enables a user to move frame-by-frame in either direction.
stopping thread
The thread that causes a program being debugged to stop.
storage class specifier
A keyword (auto, register, static, or extern) that defines the potential lifetime of the storage containing an object.
stream
(1) A contiguous group of data elements being transmitted, or intended for transmission, in character or binary-digit form, using a defined format. (2) A file access object that allows access to an ordered sequence of characters, as described by the ISO C standard. A stream provides the additional services of user-selectable buffering and formatted input and output. (3) In text processing, treating the entire text as a single string, even when the string is broken into lines for viewing purposes.
stream buffer
A stream buffer is a buffer between the ultimate consumer, ultimate producer, and the I/O Stream Library functions that format data. It is implemented in the I/O Stream Library by the streambuf class and the classes derived from streambuf.
string
A contiguous sequence of characters.
string literal
A contiguous sequence of zero or more characters enclosed in double quotation marks that is itself data, rather than a reference to data.
structure
A construct that contains an ordered group of data objects. Unlike an array, the data objects within a structure can have varied data types.
structured exception handling
A mechanism for handling system exceptions that matches exceptions with handlers based on the value returned from an exception filter expression. It allows C programmers exception-handling capabilities similar to those offered by C++. See exception handling.
structure tag
The identifier that names a structure data type.
subclass
See derived class.
subscript
One or more expressions, each enclosed in brackets, that follow an array name. A subscript refers to an element in an array.
subset
A set in which each element is also an element of another specified set. Contrast with superset.
subsystem
A secondary or subordinate system, usually capable of operating independently of, or asynchronously with, a controlling system. T.
subtree
A tree structure created by arbitrarily denoting a node to be the root node in a tree. A subtree is always part of a whole tree. See tree, root, node.
superclass
See base class, abstract class.
superset
Given two sets, A and B, A is a superset of B if all elements of B are also elements of A. Contrast with subset.
super video graphics adapter (SVGA)
A graphics adapter that can display 256 colors with a resolution of 1024 by 768 pixels. See video graphics adapter.
switch expression
The controlling expression of a switch statement.
switch statement
A C or C++ language statement that causes control to be transferred to one of several statements, depending on the value of an expression.
symbolic name
(1) A unique name used to represent an entity such as a field, file, data structure, or label. IBM. (2) One or more characters with visible glyphs, enclosed between angle brackets.
synchronous
(1) Pertaining to two or more processes that depend on the occurrence of specific events such as common timing signals. T. (2) Occurring with a regular or predictable time relationship. IBM.
system default
A default value defined in the system profile. IBM.