3697 lines
147 KiB
HTML
3697 lines
147 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
|
<html>
|
|
<head>
|
|
<meta name="generator" content="HTML Tidy, see www.w3.org">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
|
<link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 -->
|
|
<!-- Copyright (c) 2001 The Open Group, All Rights Reserved -->
|
|
<title>Definitions</title>
|
|
</head>
|
|
<body bgcolor="white">
|
|
|
|
<basefont size="3"> <!--header start-->
|
|
<center><font size="2">The Open Group Base Specifications Issue 6<br>
|
|
IEEE Std 1003.1-2001<br>
|
|
Copyright © 2001 The IEEE and The Open Group, All Rights reserved.</font></center>
|
|
|
|
<!--header end-->
|
|
<hr size="2" noshade>
|
|
<h2><a name="tag_03"></a>Definitions</h2>
|
|
|
|
<p>For the purposes of IEEE Std 1003.1-2001, the terms and definitions given in <a href="#tag_03">Definitions</a> apply.
|
|
<basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>No shading to denote extensions or options occurs in this chapter. Where the terms and definitions given in this chapter are
|
|
used elsewhere in text related to extensions and options, they are shaded as appropriate.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_01"></a>Abortive Release</h3>
|
|
|
|
<p>An abrupt termination of a network connection that may result in the loss of data.</p>
|
|
|
|
<h3><a name="tag_03_02"></a>Absolute Pathname</h3>
|
|
|
|
<p>A pathname beginning with a single or more than two slashes; see also <a href="#tag_03_266">Pathname</a> . <basefont size=
|
|
"2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Pathname Resolution is defined in detail in <a href="xbd_chap04.html#tag_04_11"><i>Pathname Resolution</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_03"></a>Access Mode</h3>
|
|
|
|
<p>A particular form of access permitted to a file.</p>
|
|
|
|
<h3><a name="tag_03_04"></a>Additional File Access Control Mechanism</h3>
|
|
|
|
<p>An implementation-defined mechanism that is layered upon the access control mechanisms defined here, but which do not grant
|
|
permissions beyond those defined herein, although they may further restrict them. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File Access Permissions are defined in detail in <a href="xbd_chap04.html#tag_04_04"><i>File Access Permissions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_05"></a>Address Space</h3>
|
|
|
|
<p>The memory locations that can be referenced by a process or the threads of a process.</p>
|
|
|
|
<h3><a name="tag_03_06"></a>Advisory Information</h3>
|
|
|
|
<p>An interface that advises the implementation on (portable) application behavior so that it can optimize the system.</p>
|
|
|
|
<h3><a name="tag_03_07"></a>Affirmative Response</h3>
|
|
|
|
<p>An input string that matches one of the responses acceptable to the <i>LC_MESSAGES</i> category keyword <b>yesexpr</b>, matching
|
|
an extended regular expression in the current locale. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>LC_MESSAGES</i> category is defined in detail in <a href="xbd_chap07.html#tag_07_03_06"><i>LC_MESSAGES</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_08"></a>Alert</h3>
|
|
|
|
<p>To cause the user's terminal to give some audible or visual indication that an error or some other event has occurred. When the
|
|
standard output is directed to a terminal device, the method for alerting the terminal user is unspecified. When the standard
|
|
output is not directed to a terminal device, the alert is accomplished by writing the <alert> to standard output (unless the
|
|
utility description indicates that the use of standard output produces undefined results in this case).</p>
|
|
|
|
<h3><a name="tag_03_09"></a>Alert Character (<alert>)</h3>
|
|
|
|
<p>A character that in the output stream should cause a terminal to alert its user via a visual or audible notification. It is the
|
|
character designated by <tt>'\a'</tt> in the C language. It is unspecified whether this character is the exact sequence transmitted
|
|
to an output device by the system to accomplish the alert function.</p>
|
|
|
|
<h3><a name="tag_03_10"></a>Alias Name</h3>
|
|
|
|
<p>In the shell command language, a word consisting solely of underscores, digits, and alphabetics from the portable character set
|
|
and any of the following characters: <tt>'!'</tt> , <tt>'%'</tt> , <tt>','</tt> , <tt>'@'</tt> .</p>
|
|
|
|
<p>Implementations may allow other characters within alias names as an extension. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The Portable Character Set is defined in detail in <a href="xbd_chap06.html#tag_06_01"><i>Portable Character Set</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_11"></a>Alignment</h3>
|
|
|
|
<p>A requirement that objects of a particular type be located on storage boundaries with addresses that are particular multiples of
|
|
a byte address. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also the ISO C standard, Section B3.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_12"></a>Alternate File Access Control Mechanism</h3>
|
|
|
|
<p>An implementation-defined mechanism that is independent of the access control mechanisms defined herein, and which if enabled on
|
|
a file may either restrict or extend the permissions of a given user. IEEE Std 1003.1-2001 defines when such mechanisms
|
|
can be enabled and when they are disabled. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File Access Permissions are defined in detail in <a href="xbd_chap04.html#tag_04_04"><i>File Access Permissions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_13"></a>Alternate Signal Stack</h3>
|
|
|
|
<p>Memory associated with a thread, established upon request by the implementation for a thread, separate from the thread signal
|
|
stack, in which signal handlers responding to signals sent to that thread may be executed.</p>
|
|
|
|
<h3><a name="tag_03_14"></a>Ancillary Data</h3>
|
|
|
|
<p>Protocol-specific, local system-specific, or optional information. The information can be both local or end-to-end significant,
|
|
header information, part of a data portion, protocol-specific, and implementation or system-specific.</p>
|
|
|
|
<h3><a name="tag_03_15"></a>Angle Brackets</h3>
|
|
|
|
<p>The characters <tt>'<'</tt> (left-angle-bracket) and <tt>'>'</tt> (right-angle-bracket). When used in the phrase
|
|
"enclosed in angle brackets", the symbol <tt>'<'</tt> immediately precedes the object to be enclosed, and <tt>'>'</tt>
|
|
immediately follows it. When describing these characters in the portable character set, the names <less-than-sign> and
|
|
<greater-than-sign> are used.</p>
|
|
|
|
<h3><a name="tag_03_16"></a>Application</h3>
|
|
|
|
<p>A computer program that performs some desired function.</p>
|
|
|
|
<h3><a name="tag_03_17"></a>Application Address</h3>
|
|
|
|
<p>Endpoint address of a specific application.</p>
|
|
|
|
<h3><a name="tag_03_18"></a>Application Program Interface (API)</h3>
|
|
|
|
<p>The definition of syntax and semantics for providing computer system services.</p>
|
|
|
|
<h3><a name="tag_03_19"></a>Appropriate Privileges</h3>
|
|
|
|
<p>An implementation-defined means of associating privileges with a process with regard to the function calls, function call
|
|
options, and the commands that need special privileges. There may be zero or more such means. These means (or lack thereof) are
|
|
described in the conformance document. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Function calls are defined in the System Interfaces volume of IEEE Std 1003.1-2001, and commands are defined in the
|
|
Shell and Utilities volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_20"></a>Argument</h3>
|
|
|
|
<p>In the shell command language, a parameter passed to a utility as the equivalent of a single string in the <i>argv</i> array
|
|
created by one of the <i>exec</i> functions. An argument is one of the options, option-arguments, or operands following the command
|
|
name. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The Utility Argument Syntax is defined in detail in <a href="xbd_chap12.html#tag_12_01"><i>Utility Argument Syntax</i></a> and
|
|
the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href="../utilities/xcu_chap02.html#tag_02_09_01_01">Section
|
|
2.9.1.1, Command Search and Execution</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<p>In the C language, an expression in a function call expression or a sequence of preprocessing tokens in a function-like macro
|
|
invocation.</p>
|
|
|
|
<h3><a name="tag_03_21"></a>Arm (a Timer)</h3>
|
|
|
|
<p>To start a timer measuring the passage of time, enabling notifying a process when the specified time or time interval has
|
|
passed.</p>
|
|
|
|
<h3><a name="tag_03_22"></a>Asterisk</h3>
|
|
|
|
<p>The character <tt>'*'</tt> .</p>
|
|
|
|
<h3><a name="tag_03_23"></a>Async-Cancel-Safe Function</h3>
|
|
|
|
<p>A function that may be safely invoked by an application while the asynchronous form of cancelation is enabled. No function is
|
|
async-cancel-safe unless explicitly described as such.</p>
|
|
|
|
<h3><a name="tag_03_24"></a>Asynchronous Events</h3>
|
|
|
|
<p>Events that occur independently of the execution of the application.</p>
|
|
|
|
<h3><a name="tag_03_25"></a>Asynchronous Input and Output</h3>
|
|
|
|
<p>A functionality enhancement to allow an application process to queue data input and output commands with asynchronous
|
|
notification of completion.</p>
|
|
|
|
<h3><a name="tag_03_26"></a>Async-Signal-Safe Function</h3>
|
|
|
|
<p>A function that may be invoked, without restriction, from signal-catching functions. No function is async-signal-safe unless
|
|
explicitly described as such.</p>
|
|
|
|
<h3><a name="tag_03_27"></a>Asynchronously-Generated Signal</h3>
|
|
|
|
<p>A signal that is not attributable to a specific thread. Examples are signals sent via <a href=
|
|
"../functions/kill.html"><i>kill</i>()</a>, signals sent from the keyboard, and signals delivered to process groups. Being
|
|
asynchronous is a property of how the signal was generated and not a property of the signal number. All signals may be generated
|
|
asynchronously. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/kill.html"><i>kill</i>()</a> function is defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_28"></a>Asynchronous I/O Completion</h3>
|
|
|
|
<p>For an asynchronous read or write operation, when a corresponding synchronous read or write would have completed and when any
|
|
associated status fields have been updated.</p>
|
|
|
|
<h3><a name="tag_03_29"></a>Asynchronous I/O Operation</h3>
|
|
|
|
<p>An I/O operation that does not of itself cause the thread requesting the I/O to be blocked from further use of the
|
|
processor.</p>
|
|
|
|
<p>This implies that the process and the I/O operation may be running concurrently.</p>
|
|
|
|
<h3><a name="tag_03_30"></a>Authentication</h3>
|
|
|
|
<p>The process of validating a user or process to verify that the user or process is not a counterfeit.</p>
|
|
|
|
<h3><a name="tag_03_31"></a>Authorization</h3>
|
|
|
|
<p>The process of verifying that a user or process has permission to use a resource in the manner requested.</p>
|
|
|
|
<p>To ensure security, the user or process would also need to be authenticated before granting access.</p>
|
|
|
|
<h3><a name="tag_03_32"></a>Background Job</h3>
|
|
|
|
<p>See <i>Background Process Group</i> in <a href="#tag_03_34">Background Process Group (or Background Job)</a> .</p>
|
|
|
|
<h3><a name="tag_03_33"></a>Background Process</h3>
|
|
|
|
<p>A process that is a member of a background process group.</p>
|
|
|
|
<h3><a name="tag_03_34"></a>Background Process Group (or Background Job)</h3>
|
|
|
|
<p>Any process group, other than a foreground process group, that is a member of a session that has established a connection with a
|
|
controlling terminal.</p>
|
|
|
|
<h3><a name="tag_03_35"></a>Backquote</h3>
|
|
|
|
<p>The character <tt>'`'</tt> , also known as a grave accent.</p>
|
|
|
|
<h3><a name="tag_03_36"></a>Backslash</h3>
|
|
|
|
<p>The character <tt>'\'</tt> , also known as a reverse solidus.</p>
|
|
|
|
<h3><a name="tag_03_37"></a>Backspace Character (<backspace>)</h3>
|
|
|
|
<p>A character that, in the output stream, should cause printing (or displaying) to occur one column position previous to the
|
|
position about to be printed. If the position about to be printed is at the beginning of the current line, the behavior is
|
|
unspecified. It is the character designated by <tt>'\b'</tt> in the C language. It is unspecified whether this character is the
|
|
exact sequence transmitted to an output device by the system to accomplish the backspace function. The <backspace> defined
|
|
here is not necessarily the ERASE special character. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Special Characters are defined in detail in <a href="xbd_chap11.html#tag_11_01_09"><i>Special Characters</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_38"></a>Barrier</h3>
|
|
|
|
<p>A synchronization object that allows multiple threads to synchronize at a particular point in their execution.</p>
|
|
|
|
<h3><a name="tag_03_39"></a>Base Character</h3>
|
|
|
|
<p>One of the set of characters defined in the Latin alphabet. In Western European languages other than English, these characters
|
|
are commonly used with diacritical marks (accents, cedilla, and so on) to extend the range of characters in an alphabet.</p>
|
|
|
|
<h3><a name="tag_03_40"></a>Basename</h3>
|
|
|
|
<p>The final, or only, filename in a pathname.</p>
|
|
|
|
<h3><a name="tag_03_41"></a>Basic Regular Expression (BRE)</h3>
|
|
|
|
<p>A regular expression (see <a href="#tag_03_316">Regular Expression</a> ) used by the majority of utilities that select strings
|
|
from a set of character strings. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Basic Regular Expressions are described in detail in <a href="xbd_chap09.html#tag_09_03"><i>Basic Regular Expressions</i></a>
|
|
.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_42"></a>Batch Access List</h3>
|
|
|
|
<p>A list of user IDs and group IDs of those users and groups authorized to place batch jobs in a batch queue.</p>
|
|
|
|
<p>A batch access list is associated with a batch queue. A batch server uses the batch access list of a batch queue as one of the
|
|
criteria in deciding to put a batch job in a batch queue.</p>
|
|
|
|
<h3><a name="tag_03_43"></a>Batch Administrator</h3>
|
|
|
|
<p>A user that is authorized to modify all the attributes of queues and jobs and to change the status of a batch server.</p>
|
|
|
|
<h3><a name="tag_03_44"></a>Batch Client</h3>
|
|
|
|
<p>A computational entity that utilizes batch services by making requests of batch servers.</p>
|
|
|
|
<p>Batch clients often provide the means by which users access batch services, although a batch server may act as a batch client by
|
|
virtue of making requests of another batch server.</p>
|
|
|
|
<h3><a name="tag_03_45"></a>Batch Destination</h3>
|
|
|
|
<p>The batch server in a batch system to which a batch job should be sent for processing.</p>
|
|
|
|
<p>Acceptance of a batch job at a batch destination is the responsibility of a receiving batch server. A batch destination may
|
|
consist of a batch server-specific portion, a network-wide portion, or both. The batch server-specific portion is referred to as
|
|
the "batch queue". The network-wide portion is referred to as a "batch server name".</p>
|
|
|
|
<h3><a name="tag_03_46"></a>Batch Destination Identifier</h3>
|
|
|
|
<p>A string that identifies a specific batch destination.</p>
|
|
|
|
<p>A string of characters in the portable character set used to specify a particular batch destination. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The Portable Character Set is defined in detail in <a href="xbd_chap06.html#tag_06_01"><i>Portable Character Set</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_47"></a>Batch Directive</h3>
|
|
|
|
<p>A line from a file that is interpreted by the batch server. The line is usually in the form of a comment and is an additional
|
|
means of passing options to the <a href="../utilities/qsub.html"><i>qsub</i></a> utility. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../utilities/qsub.html"><i>qsub</i></a> utility is defined in detail in the Shell and Utilities volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_48"></a>Batch Job</h3>
|
|
|
|
<p>A set of computational tasks for a computing system.</p>
|
|
|
|
<p>Batch jobs are managed by batch servers.</p>
|
|
|
|
<p>Once created, a batch job may be executing or pending execution. A batch job that is executing has an associated session leader
|
|
(a process) that initiates and monitors the computational tasks of the batch job.</p>
|
|
|
|
<h3><a name="tag_03_49"></a>Batch Job Attribute</h3>
|
|
|
|
<p>A named data type whose value affects the processing of a batch job.</p>
|
|
|
|
<p>The values of the attributes of a batch job affect the processing of that job by the batch server that manages the batch
|
|
job.</p>
|
|
|
|
<h3><a name="tag_03_50"></a>Batch Job Identifier</h3>
|
|
|
|
<p>A unique name for a batch job. A name that is unique among all other batch job identifiers in a batch system and that identifies
|
|
the batch server to which the batch job was originally submitted.</p>
|
|
|
|
<h3><a name="tag_03_51"></a>Batch Job Name</h3>
|
|
|
|
<p>A label that is an attribute of a batch job. The batch job name is not necessarily unique.</p>
|
|
|
|
<h3><a name="tag_03_52"></a>Batch Job Owner</h3>
|
|
|
|
<p>The <i>username</i>@ <i>hostname</i> of the user submitting the batch job, where <i>username</i> is a user name (see also <a
|
|
href="#tag_03_426">User Name</a> ) and <i>hostname</i> is a network host name.</p>
|
|
|
|
<h3><a name="tag_03_53"></a>Batch Job Priority</h3>
|
|
|
|
<p>A value specified by the user that may be used by an implementation to determine the order in which batch jobs are selected to
|
|
be executed. Job priority has a numeric value in the range -1024 to 1023. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The batch job priority is not the execution priority (nice value) of the batch job.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_54"></a>Batch Job State</h3>
|
|
|
|
<p>An attribute of a batch job which determines the types of requests that the batch server that manages the batch job can accept
|
|
for the batch job. Valid states include QUEUED, RUNNING, HELD, WAITING, EXITING, and TRANSITING.</p>
|
|
|
|
<h3><a name="tag_03_55"></a>Batch Name Service</h3>
|
|
|
|
<p>A service that assigns batch names that are unique within the batch name space, and that can translate a unique batch name into
|
|
the location of the named batch entity.</p>
|
|
|
|
<h3><a name="tag_03_56"></a>Batch Name Space</h3>
|
|
|
|
<p>The environment within which a batch name is known to be unique.</p>
|
|
|
|
<h3><a name="tag_03_57"></a>Batch Node</h3>
|
|
|
|
<p>A host containing part or all of a batch system.</p>
|
|
|
|
<p>A batch node is a host meeting at least one of the following conditions:</p>
|
|
|
|
<ul>
|
|
<li>
|
|
<p>Capable of executing a batch client</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Contains a routing batch queue</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Contains an execution batch queue</p>
|
|
</li>
|
|
</ul>
|
|
|
|
<h3><a name="tag_03_58"></a>Batch Operator</h3>
|
|
|
|
<p>A user that is authorized to modify some, but not all, of the attributes of jobs and queues, and may change the status of the
|
|
batch server.</p>
|
|
|
|
<h3><a name="tag_03_59"></a>Batch Queue</h3>
|
|
|
|
<p>A manageable object that represents a set of batch jobs and is managed by a single batch server. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>A set of batch jobs is called a batch queue largely for historical reasons. Jobs are selected from the batch queue for
|
|
execution based on attributes such as priority, resource requirements, and hold conditions.
|
|
|
|
<p>See also the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap03.html#tag_03_01_02">Section 3.1.2, Batch Queues</a>.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_60"></a>Batch Queue Attribute</h3>
|
|
|
|
<p>A named data type whose value affects the processing of all batch jobs that are members of the batch queue.</p>
|
|
|
|
<p>A batch queue has attributes that affect the processing of batch jobs that are members of the batch queue.</p>
|
|
|
|
<h3><a name="tag_03_61"></a>Batch Queue Position</h3>
|
|
|
|
<p>The place, relative to other jobs in the batch queue, occupied by a particular job in a batch queue. This is defined in part by
|
|
submission time and priority; see also <a href="#tag_03_62">Batch Queue Priority</a> .</p>
|
|
|
|
<h3><a name="tag_03_62"></a>Batch Queue Priority</h3>
|
|
|
|
<p>The maximum job priority allowed for any batch job in a given batch queue.</p>
|
|
|
|
<p>The batch queue priority is set and may be changed by users with appropriate privilege. The priority is bounded in an
|
|
implementation-defined manner.</p>
|
|
|
|
<h3><a name="tag_03_63"></a>Batch Rerunability</h3>
|
|
|
|
<p>An attribute of a batch job indicating that it may be rerun after an abnormal termination from the beginning without affecting
|
|
the validity of the results.</p>
|
|
|
|
<h3><a name="tag_03_64"></a>Batch Restart</h3>
|
|
|
|
<p>The action of resuming the processing of a batch job from the point of the last checkpoint. Typically, this is done if the batch
|
|
job has been interrupted because of a system failure.</p>
|
|
|
|
<h3><a name="tag_03_65"></a>Batch Server</h3>
|
|
|
|
<p>A computational entity that provides batch services.</p>
|
|
|
|
<h3><a name="tag_03_66"></a>Batch Server Name</h3>
|
|
|
|
<p>A string of characters in the portable character set used to specify a particular server in a network. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The Portable Character Set is defined in detail in <a href="xbd_chap06.html#tag_06_01"><i>Portable Character Set</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_67"></a>Batch Service</h3>
|
|
|
|
<p>Computational and organizational services performed by a batch system on behalf of batch jobs.</p>
|
|
|
|
<p>Batch services are of two types: requested and deferred. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Batch Services are listed in the Shell and Utilities volume of IEEE Std 1003.1-2001, Table 3-5, Batch Services
|
|
Summary.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_68"></a>Batch Service Request</h3>
|
|
|
|
<p>A solicitation of services from a batch client to a batch server.</p>
|
|
|
|
<p>A batch service request may entail the exchange of any number of messages between the batch client and the batch server.</p>
|
|
|
|
<p>When naming specific types of service requests, the term "request" is qualified by the type of request, as in <i>Queue Batch
|
|
Job Request</i> and <i>Delete Batch Job Request</i>.</p>
|
|
|
|
<h3><a name="tag_03_69"></a>Batch Submission</h3>
|
|
|
|
<p>The process by which a batch client requests that a batch server create a batch job via a <i>Queue Job Request</i> to perform a
|
|
specified computational task.</p>
|
|
|
|
<h3><a name="tag_03_70"></a>Batch System</h3>
|
|
|
|
<p>A collection of one or more batch servers.</p>
|
|
|
|
<h3><a name="tag_03_71"></a>Batch Target User</h3>
|
|
|
|
<p>The name of a user on the batch destination batch server.</p>
|
|
|
|
<p>The target user is the user name under whose account the batch job is to execute on the destination batch server.</p>
|
|
|
|
<h3><a name="tag_03_72"></a>Batch User</h3>
|
|
|
|
<p>A user who is authorized to make use of batch services.</p>
|
|
|
|
<h3><a name="tag_03_73"></a>Bind</h3>
|
|
|
|
<p>The process of assigning a network address to an endpoint.</p>
|
|
|
|
<h3><a name="tag_03_74"></a>Blank Character (<blank>)</h3>
|
|
|
|
<p>One of the characters that belong to the <b>blank</b> character class as defined via the <i>LC_CTYPE</i> category in the current
|
|
locale. In the POSIX locale, a <blank> is either a <tab> or a <space>.</p>
|
|
|
|
<h3><a name="tag_03_75"></a>Blank Line</h3>
|
|
|
|
<p>A line consisting solely of zero or more <blank>s terminated by a <newline>; see also <a href="#tag_03_144">Empty
|
|
Line</a> .</p>
|
|
|
|
<h3><a name="tag_03_76"></a>Blocked Process (or Thread)</h3>
|
|
|
|
<p>A process (or thread) that is waiting for some condition (other than the availability of a processor) to be satisfied before it
|
|
can continue execution.</p>
|
|
|
|
<h3><a name="tag_03_77"></a>Blocking</h3>
|
|
|
|
<p>A property of an open file description that causes function calls associated with it to wait for the requested action to be
|
|
performed before returning.</p>
|
|
|
|
<h3><a name="tag_03_78"></a>Block-Mode Terminal</h3>
|
|
|
|
<p>A terminal device operating in a mode incapable of the character-at-a-time input and output operations described by some of the
|
|
standard utilities. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Output Devices and Terminal Types are defined in detail in <a href="xbd_chap10.html#tag_10_02"><i>Output Devices and Terminal
|
|
Types</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_79"></a>Block Special File</h3>
|
|
|
|
<p>A file that refers to a device. A block special file is normally distinguished from a character special file by providing access
|
|
to the device in a manner such that the hardware characteristics of the device are not visible.</p>
|
|
|
|
<h3><a name="tag_03_80"></a>Braces</h3>
|
|
|
|
<p>The characters <tt>'{'</tt> (left brace) and <tt>'}'</tt> (right brace), also known as curly braces. When used in the phrase
|
|
"enclosed in (curly) braces" the symbol <tt>'{'</tt> immediately precedes the object to be enclosed, and <tt>'}'</tt> immediately
|
|
follows it. When describing these characters in the portable character set, the names <left-brace> and <right-brace>
|
|
are used.</p>
|
|
|
|
<h3><a name="tag_03_81"></a>Brackets</h3>
|
|
|
|
<p>The characters <tt>'['</tt> (left-bracket) and <tt>']'</tt> (right-bracket), also known as square brackets. When used in the
|
|
phrase "enclosed in (square) brackets" the symbol <tt>'['</tt> immediately precedes the object to be enclosed, and <tt>']'</tt>
|
|
immediately follows it. When describing these characters in the portable character set, the names <left-square-bracket> and
|
|
<right-square-bracket> are used.</p>
|
|
|
|
<h3><a name="tag_03_82"></a>Broadcast</h3>
|
|
|
|
<p>The transfer of data from one endpoint to several endpoints, as described in RFC 919 and RFC 922.</p>
|
|
|
|
<h3><a name="tag_03_83"></a>Built-In Utility (or Built-In)</h3>
|
|
|
|
<p>A utility implemented within a shell. The utilities referred to as special built-ins have special qualities. Unless qualified,
|
|
the term "built-in" includes the special built-in utilities. Regular built-ins are not required to be actually built into the
|
|
shell on the implementation, but they do have special command-search qualities. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Special Built-In Utilities are defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_14">Section 2.14, Special Built-In Utilities</a>.
|
|
|
|
<p>Regular Built-In Utilities are defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_09_01_01">Section 2.9.1.1, Command Search and Execution</a>.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_84"></a>Byte</h3>
|
|
|
|
<p>An individually addressable unit of data storage that is exactly an octet, used to store a character or a portion of a
|
|
character; see also <a href="#tag_03_87">Character</a> . A byte is composed of a contiguous sequence of 8 bits. The least
|
|
significant bit is called the "low-order" bit; the most significant is called the "high-order" bit. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The definition of byte from the ISO C standard is broader than the above and might accommodate hardware architectures with
|
|
different sized addressable units than octets.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_85"></a>Byte Input/Output Functions</h3>
|
|
|
|
<p>The functions that perform byte-oriented input from streams or byte-oriented output to streams: <a href=
|
|
"../functions/fgetc.html"><i>fgetc</i>()</a>, <a href="../functions/fgets.html"><i>fgets</i>()</a>, <a href=
|
|
"../functions/fprintf.html"><i>fprintf</i>()</a>, <a href="../functions/fputc.html"><i>fputc</i>()</a>, <a href=
|
|
"../functions/fputs.html"><i>fputs</i>()</a>, <a href="../functions/fread.html"><i>fread</i>()</a>, <a href=
|
|
"../functions/fscanf.html"><i>fscanf</i>()</a>, <a href="../functions/fwrite.html"><i>fwrite</i>()</a>, <a href=
|
|
"../functions/getc.html"><i>getc</i>()</a>, <a href="../functions/getchar.html"><i>getchar</i>()</a>, <a href=
|
|
"../functions/gets.html"><i>gets</i>()</a>, <a href="../functions/printf.html"><i>printf</i>()</a>, <a href=
|
|
"../functions/putc.html"><i>putc</i>()</a>, <a href="../functions/putchar.html"><i>putchar</i>()</a>, <a href=
|
|
"../functions/puts.html"><i>puts</i>()</a>, <a href="../functions/scanf.html"><i>scanf</i>()</a>, <a href=
|
|
"../functions/ungetc.html"><i>ungetc</i>()</a>, <a href="../functions/vfprintf.html"><i>vfprintf</i>()</a>, and <a href=
|
|
"../functions/vprintf.html"><i>vprintf</i>()</a>. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Functions are defined in detail in the System Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_86"></a>Carriage-Return Character (<carriage-return>)</h3>
|
|
|
|
<p>A character that in the output stream indicates that printing should start at the beginning of the same physical line in which
|
|
the <carriage-return> occurred. It is the character designated by <tt>'\r'</tt> in the C language. It is unspecified whether
|
|
this character is the exact sequence transmitted to an output device by the system to accomplish the movement to the beginning of
|
|
the line.</p>
|
|
|
|
<h3><a name="tag_03_87"></a>Character</h3>
|
|
|
|
<p>A sequence of one or more bytes representing a single graphic symbol or control code. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>This term corresponds to the ISO C standard term multi-byte character, where a single-byte character is a special case of
|
|
a multi-byte character. Unlike the usage in the ISO C standard, <i>character</i> here has no necessary relationship with
|
|
storage space, and <i>byte</i> is used when storage space is discussed.
|
|
|
|
<p>See the definition of the portable character set in <a href="xbd_chap06.html#tag_06_01"><i>Portable Character Set</i></a> for a
|
|
further explanation of the graphical representations of (abstract) characters, as opposed to character encodings.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_88"></a>Character Array</h3>
|
|
|
|
<p>An array of elements of type <b>char</b>.</p>
|
|
|
|
<h3><a name="tag_03_89"></a>Character Class</h3>
|
|
|
|
<p>A named set of characters sharing an attribute associated with the name of the class. The classes and the characters that they
|
|
contain are dependent on the value of the <i>LC_CTYPE</i> category in the current locale. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>LC_CTYPE</i> category is defined in detail in <a href="xbd_chap07.html#tag_07_03_01"><i>LC_CTYPE</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_90"></a>Character Set</h3>
|
|
|
|
<p>A finite set of different characters used for the representation, organization, or control of data.</p>
|
|
|
|
<h3><a name="tag_03_91"></a>Character Special File</h3>
|
|
|
|
<p>A file that refers to a device. One specific type of character special file is a terminal device file. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The General Terminal Interface is defined in detail in <a href="xbd_chap11.html#tag_11"><i>General Terminal Interface</i></a>
|
|
.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_92"></a>Character String</h3>
|
|
|
|
<p>A contiguous sequence of characters terminated by and including the first null byte.</p>
|
|
|
|
<h3><a name="tag_03_93"></a>Child Process</h3>
|
|
|
|
<p>A new process created (by <a href="../functions/fork.html"><i>fork</i>()</a>, <a href=
|
|
"../functions/posix_spawn.html"><i>posix_spawn</i>()</a>, or <a href="../functions/posix_spawnp.html"><i>posix_spawnp</i>()</a>) by
|
|
a given process. A child process remains the child of the creating process as long as both processes continue to exist. <basefont
|
|
size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/fork.html"><i>fork</i>()</a>, <a href="../functions/posix_spawn.html"><i>posix_spawn</i>()</a>, and
|
|
<a href="../functions/posix_spawnp.html"><i>posix_spawnp</i>()</a> functions are defined in detail in the System Interfaces volume
|
|
of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_94"></a>Circumflex</h3>
|
|
|
|
<p>The character <tt>'^'</tt> .</p>
|
|
|
|
<h3><a name="tag_03_95"></a>Clock</h3>
|
|
|
|
<p>A software or hardware object that can be used to measure the apparent or actual passage of time.</p>
|
|
|
|
<p>The current value of the time measured by a clock can be queried and, possibly, set to a value within the legal range of the
|
|
clock.</p>
|
|
|
|
<h3><a name="tag_03_96"></a>Clock Jump</h3>
|
|
|
|
<p>The difference between two successive distinct values of a clock, as observed from the application via one of the "get time''
|
|
operations.</p>
|
|
|
|
<h3><a name="tag_03_97"></a>Clock Tick</h3>
|
|
|
|
<p>An interval of time; an implementation-defined number of these occur each second. Clock ticks are one of the units that may be
|
|
used to express a value found in type <b>clock_t</b>.</p>
|
|
|
|
<h3><a name="tag_03_98"></a>Coded Character Set</h3>
|
|
|
|
<p>A set of unambiguous rules that establishes a character set and the one-to-one relationship between each character of the set
|
|
and its bit representation.</p>
|
|
|
|
<h3><a name="tag_03_99"></a>Codeset</h3>
|
|
|
|
<p>The result of applying rules that map a numeric code value to each element of a character set. An element of a character set may
|
|
be related to more than one numeric code value but the reverse is not true. However, for state-dependent encodings the relationship
|
|
between numeric code values and elements of a character set may be further controlled by state information. The character set may
|
|
contain fewer elements than the total number of possible numeric code values; that is, some code values may be unassigned.
|
|
<basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Character Encoding is defined in detail in <a href="xbd_chap06.html#tag_06_02"><i>Character Encoding</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_100"></a>Collating Element</h3>
|
|
|
|
<p>The smallest entity used to determine the logical ordering of character or wide-character strings; see also <a href=
|
|
"#tag_03_102">Collation Sequence</a> . A collating element consists of either a single character, or two or more characters
|
|
collating as a single entity. The value of the <i>LC_COLLATE</i> category in the current locale determines the current set of
|
|
collating elements.</p>
|
|
|
|
<h3><a name="tag_03_101"></a>Collation</h3>
|
|
|
|
<p>The logical ordering of character or wide-character strings according to defined precedence rules. These rules identify a
|
|
collation sequence between the collating elements, and such additional rules that can be used to order strings consisting of
|
|
multiple collating elements.</p>
|
|
|
|
<h3><a name="tag_03_102"></a>Collation Sequence</h3>
|
|
|
|
<p>The relative order of collating elements as determined by the setting of the <i>LC_COLLATE</i> category in the current locale.
|
|
The collation sequence is used for sorting and is determined from the collating weights assigned to each collating element. In the
|
|
absence of weights, the collation sequence is the order in which collating elements are specified between <b>order_start</b> and
|
|
<b>order_end</b> keywords in the <i>LC_COLLATE</i> category.</p>
|
|
|
|
<p>Multi-level sorting is accomplished by assigning elements one or more collation weights, up to the limit {COLL_WEIGHTS_MAX}. On
|
|
each level, elements may be given the same weight (at the primary level, called an equivalence class; see also <a href=
|
|
"#tag_03_150">Equivalence Class</a> ) or be omitted from the sequence. Strings that collate equally using the first assigned weight
|
|
(primary ordering) are then compared using the next assigned weight (secondary ordering), and so on. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>{COLL_WEIGHTS_MAX} is defined in detail in <a href="limits.h.html"><i><limits.h></i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_103"></a>Column Position</h3>
|
|
|
|
<p>A unit of horizontal measure related to characters in a line.</p>
|
|
|
|
<p>It is assumed that each character in a character set has an intrinsic column width independent of any output device. Each
|
|
printable character in the portable character set has a column width of one. The standard utilities, when used as described in
|
|
IEEE Std 1003.1-2001, assume that all characters have integral column widths. The column width of a character is not
|
|
necessarily related to the internal representation of the character (numbers of bits or bytes).</p>
|
|
|
|
<p>The column position of a character in a line is defined as one plus the sum of the column widths of the preceding characters in
|
|
the line. Column positions are numbered starting from 1.</p>
|
|
|
|
<h3><a name="tag_03_104"></a>Command</h3>
|
|
|
|
<p>A directive to the shell to perform a particular task. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Shell Commands are defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_09">Section 2.9, Shell Commands</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_105"></a>Command Language Interpreter</h3>
|
|
|
|
<p>An interface 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. It is possible for applications to invoke utilities through a number of interfaces, which
|
|
are collectively considered to act as command interpreters. The most obvious of these are the <a href=
|
|
"../utilities/sh.html"><i>sh</i></a> utility and the <a href="../functions/system.html"><i>system</i>()</a> function, although <a
|
|
href="../functions/popen.html"><i>popen</i>()</a> and the various forms of <i>exec</i> may also be considered to behave as
|
|
interpreters. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../utilities/sh.html"><i>sh</i></a> utility is defined in detail in the Shell and Utilities volume of
|
|
IEEE Std 1003.1-2001.
|
|
|
|
<p>The <a href="../functions/system.html"><i>system</i>()</a>, <a href="../functions/popen.html"><i>popen</i>()</a>, and
|
|
<i>exec</i> functions are defined in detail in the System Interfaces volume of IEEE Std 1003.1-2001.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_106"></a>Composite Graphic Symbol</h3>
|
|
|
|
<p>A graphic symbol consisting of a combination of two or more other graphic symbols in a single character position, such as a
|
|
diacritical mark and a base character.</p>
|
|
|
|
<h3><a name="tag_03_107"></a>Condition Variable</h3>
|
|
|
|
<p>A synchronization object which allows a thread to suspend execution, repeatedly, until some associated predicate becomes true. A
|
|
thread whose execution is suspended on a condition variable is said to be blocked on the condition variable.</p>
|
|
|
|
<h3><a name="tag_03_108"></a>Connection</h3>
|
|
|
|
<p>An association established between two or more endpoints for the transfer of data</p>
|
|
|
|
<h3><a name="tag_03_109"></a>Connection Mode</h3>
|
|
|
|
<p>The transfer of data in the context of a connection; see also <a href="#tag_03_110">Connectionless Mode</a> .</p>
|
|
|
|
<h3><a name="tag_03_110"></a>Connectionless Mode</h3>
|
|
|
|
<p>The transfer of data other than in the context of a connection; see also <a href="#tag_03_109">Connection Mode</a> and <a href=
|
|
"#tag_03_123">Datagram</a> .</p>
|
|
|
|
<h3><a name="tag_03_111"></a>Control Character</h3>
|
|
|
|
<p>A character, other than a graphic character, that affects the recording, processing, transmission, or interpretation of
|
|
text.</p>
|
|
|
|
<h3><a name="tag_03_112"></a>Control Operator</h3>
|
|
|
|
<p>In the shell command language, a token that performs a control function. It is one of the following symbols:</p>
|
|
|
|
<blockquote>
|
|
<pre>
|
|
<tt>& && ( ) ; ;; newline | ||
|
|
</tt>
|
|
</pre>
|
|
</blockquote>
|
|
|
|
<p>The end-of-input indicator used internally by the shell is also considered a control operator. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Token Recognition is defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_03">Section 2.3, Token Recognition</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_113"></a>Controlling Process</h3>
|
|
|
|
<p>The session leader that established the connection to the controlling terminal. If the terminal subsequently ceases to be a
|
|
controlling terminal for this session, the session leader ceases to be the controlling process.</p>
|
|
|
|
<h3><a name="tag_03_114"></a>Controlling Terminal</h3>
|
|
|
|
<p>A terminal that is associated with a session. Each session may have at most one controlling terminal associated with it, and a
|
|
controlling terminal is associated with exactly one session. Certain input sequences from the controlling terminal cause signals to
|
|
be sent to all processes in the process group associated with the controlling terminal. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The General Terminal Interface is defined in detail in <a href="xbd_chap11.html#tag_11"><i>General Terminal Interface</i></a>
|
|
.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_115"></a>Conversion Descriptor</h3>
|
|
|
|
<p>A per-process unique value used to identify an open codeset conversion.</p>
|
|
|
|
<h3><a name="tag_03_116"></a>Core File</h3>
|
|
|
|
<p>A file of unspecified format that may be generated when a process terminates abnormally.</p>
|
|
|
|
<h3><a name="tag_03_117"></a>CPU Time (Execution Time)</h3>
|
|
|
|
<p>The time spent executing a process or thread, including the time spent executing system services on behalf of that process or
|
|
thread. If the Threads option is supported, then the value of the CPU-time clock for a process is implementation-defined. With this
|
|
definition the sum of all the execution times of all the threads in a process might not equal the process execution time, even in a
|
|
single-threaded process, because implementations may differ in how they account for time during context switches or for other
|
|
reasons.</p>
|
|
|
|
<h3><a name="tag_03_118"></a>CPU-Time Clock</h3>
|
|
|
|
<p>A clock that measures the execution time of a particular process or thread.</p>
|
|
|
|
<h3><a name="tag_03_119"></a>CPU-Time Timer</h3>
|
|
|
|
<p>A timer attached to a CPU-time clock.</p>
|
|
|
|
<h3><a name="tag_03_120"></a>Current Job</h3>
|
|
|
|
<p>In the context of job control, the job that will be used as the default for the <a href="../utilities/fg.html"><i>fg</i></a> or
|
|
<a href="../utilities/bg.html"><i>bg</i></a> utilities. There is at most one current job; see also <a href="#tag_03_203">Job
|
|
Control Job ID</a> .</p>
|
|
|
|
<h3><a name="tag_03_121"></a>Current Working Directory</h3>
|
|
|
|
<p>See <i>Working Directory</i> in <a href="#tag_03_436">Working Directory (or Current Working Directory)</a> .</p>
|
|
|
|
<h3><a name="tag_03_122"></a>Cursor Position</h3>
|
|
|
|
<p>The line and column position on the screen denoted by the terminal's cursor.</p>
|
|
|
|
<h3><a name="tag_03_123"></a>Datagram</h3>
|
|
|
|
<p>A unit of data transferred from one endpoint to another in connectionless mode service.</p>
|
|
|
|
<h3><a name="tag_03_124"></a>Data Segment</h3>
|
|
|
|
<p>Memory associated with a process, that can contain dynamically allocated data.</p>
|
|
|
|
<h3><a name="tag_03_125"></a>Deferred Batch Service</h3>
|
|
|
|
<p>A service that is performed as a result of events that are asynchronous with respect to requests. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Once a batch job has been created, it is subject to deferred services.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_126"></a>Device</h3>
|
|
|
|
<p>A computer peripheral or an object that appears to the application as such.</p>
|
|
|
|
<h3><a name="tag_03_127"></a>Device ID</h3>
|
|
|
|
<p>A non-negative integer used to identify a device.</p>
|
|
|
|
<h3><a name="tag_03_128"></a>Directory</h3>
|
|
|
|
<p>A file that contains directory entries. No two directory entries in the same directory have the same name.</p>
|
|
|
|
<h3><a name="tag_03_129"></a>Directory Entry (or Link)</h3>
|
|
|
|
<p>An object that associates a filename with a file. Several directory entries can associate names with the same file.</p>
|
|
|
|
<h3><a name="tag_03_130"></a>Directory Stream</h3>
|
|
|
|
<p>A sequence of all the directory entries in a particular directory. An open directory stream may be implemented using a file
|
|
descriptor.</p>
|
|
|
|
<h3><a name="tag_03_131"></a>Disarm (a Timer)</h3>
|
|
|
|
<p>To stop a timer from measuring the passage of time, disabling any future process notifications (until the timer is armed
|
|
again).</p>
|
|
|
|
<h3><a name="tag_03_132"></a>Display</h3>
|
|
|
|
<p>To output to the user's terminal. If the output is not directed to a terminal, the results are undefined.</p>
|
|
|
|
<h3><a name="tag_03_133"></a>Display Line</h3>
|
|
|
|
<p>A line of text on a physical device or an emulation thereof. Such a line will have a maximum number of characters which can be
|
|
presented. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>This may also be written as "line on the display".</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_134"></a>Dollar Sign</h3>
|
|
|
|
<p>The character <tt>'$'</tt> .</p>
|
|
|
|
<h3><a name="tag_03_135"></a>Dot</h3>
|
|
|
|
<p>In the context of naming files, the filename consisting of a single dot character ( <tt>'.'</tt> ). <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>In the context of shell special built-in utilities, see <a href="../utilities/dot.html"><i>dot</i></a> in the Shell
|
|
and Utilities volume of IEEE Std 1003.1-2001, <a href="../utilities/xcu_chap02.html#tag_02_14">Section 2.14, Special
|
|
Built-In Utilities</a>.
|
|
|
|
<p>Pathname Resolution is defined in detail in <a href="xbd_chap04.html#tag_04_11"><i>Pathname Resolution</i></a> .</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_136"></a>Dot-Dot</h3>
|
|
|
|
<p>The filename consisting solely of two dot characters ( <tt>".."</tt> ). <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Pathname Resolution is defined in detail in <a href="xbd_chap04.html#tag_04_11"><i>Pathname Resolution</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_137"></a>Double-Quote</h3>
|
|
|
|
<p>The character <tt>' ,'</tt> also known as quotation-mark. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The "double" adjective in this term refers to the two strokes in the character glyph. IEEE Std 1003.1-2001 never
|
|
uses the term "double-quote" to refer to two apostrophes or quotation marks.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_138"></a>Downshifting</h3>
|
|
|
|
<p>The conversion of an uppercase character that has a single-character lowercase representation into this lowercase
|
|
representation.</p>
|
|
|
|
<h3><a name="tag_03_139"></a>Driver</h3>
|
|
|
|
<p>A module that controls data transferred to and received from devices. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Drivers are traditionally written to be a part of the system implementation, although they are frequently written separately
|
|
from the writing of the implementation. A driver may contain processor-specific code, and therefore be non-portable.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_140"></a>Effective Group ID</h3>
|
|
|
|
<p>An attribute of a process that is used in determining various permissions, including file access permissions; see also <a href=
|
|
"#tag_03_188">Group ID</a> .</p>
|
|
|
|
<h3><a name="tag_03_141"></a>Effective User ID</h3>
|
|
|
|
<p>An attribute of a process that is used in determining various permissions, including file access permissions; see also <a href=
|
|
"#tag_03_425">User ID</a> .</p>
|
|
|
|
<h3><a name="tag_03_142"></a>Eight-Bit Transparency</h3>
|
|
|
|
<p>The ability of a software component to process 8-bit characters without modifying or utilizing any part of the character in a
|
|
way that is inconsistent with the rules of the current coded character set.</p>
|
|
|
|
<h3><a name="tag_03_143"></a>Empty Directory</h3>
|
|
|
|
<p>A directory that contains, at most, directory entries for dot and dot-dot, and has exactly one link to it, in dot-dot. No other
|
|
links to the directory may exist. It is unspecified whether an implementation can ever consider the root directory to be empty.</p>
|
|
|
|
<h3><a name="tag_03_144"></a>Empty Line</h3>
|
|
|
|
<p>A line consisting of only a <newline>; see also <a href="#tag_03_75">Blank Line</a> .</p>
|
|
|
|
<h3><a name="tag_03_145"></a>Empty String (or Null String)</h3>
|
|
|
|
<p>A string whose first byte is a null byte.</p>
|
|
|
|
<h3><a name="tag_03_146"></a>Empty Wide-Character String</h3>
|
|
|
|
<p>A wide-character string whose first element is a null wide-character code.</p>
|
|
|
|
<h3><a name="tag_03_147"></a>Encoding Rule</h3>
|
|
|
|
<p>The rules used to convert between wide-character codes and multi-byte character codes. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Stream Orientation and Encoding Rules are defined in detail in the System Interfaces volume of IEEE Std 1003.1-2001,
|
|
<a href="../functions/xsh_chap02_05.html#tag_02_05_02">Section 2.5.2, Stream Orientation and Encoding Rules</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_148"></a>Entire Regular Expression</h3>
|
|
|
|
<p>The concatenated set of one or more basic regular expressions or extended regular expressions that make up the pattern specified
|
|
for string selection. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Regular Expressions are defined in detail in <a href="xbd_chap09.html#tag_09"><i>Regular Expressions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_149"></a>Epoch</h3>
|
|
|
|
<p>The time zero hours, zero minutes, zero seconds, on January 1, 1970 Coordinated Universal Time (UTC). <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also Seconds Since the Epoch defined in <a href="xbd_chap04.html#tag_04_14"><i>Seconds Since the Epoch</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_150"></a>Equivalence Class</h3>
|
|
|
|
<p>A set of collating elements with the same primary collation weight.</p>
|
|
|
|
<p>Elements in an equivalence class are typically elements that naturally group together, such as all accented letters based on the
|
|
same base letter.</p>
|
|
|
|
<p>The collation order of elements within an equivalence class is determined by the weights assigned on any subsequent levels after
|
|
the primary weight.</p>
|
|
|
|
<h3><a name="tag_03_151"></a>Era</h3>
|
|
|
|
<p>A locale-specific method for counting and displaying years. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>LC_TIME</i> category is defined in detail in <a href="xbd_chap07.html#tag_07_03_05"><i>LC_TIME</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_152"></a>Event Management</h3>
|
|
|
|
<p>The mechanism that enables applications to register for and be made aware of external events such as data becoming available for
|
|
reading.</p>
|
|
|
|
<h3><a name="tag_03_153"></a>Executable File</h3>
|
|
|
|
<p>A regular file acceptable as a new process image file by the equivalent of the <i>exec</i> family of functions, and thus usable
|
|
as one form of a utility. The standard utilities described as compilers can produce executable files, but other unspecified methods
|
|
of producing executable files may also be provided. The internal format of an executable file is unspecified, but a conforming
|
|
application cannot assume an executable file is a text file.</p>
|
|
|
|
<h3><a name="tag_03_154"></a>Execute</h3>
|
|
|
|
<p>To perform command search and execution actions, as defined in the Shell and Utilities volume of IEEE Std 1003.1-2001;
|
|
see also <a href="#tag_03_200">Invoke</a> . <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Command Search and Execution is defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_09_01_01">Section 2.9.1.1, Command Search and Execution</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_155"></a>Execution Time</h3>
|
|
|
|
<p>See <i>CPU Time</i> in <a href="#tag_03_117">CPU Time (Execution Time)</a> .</p>
|
|
|
|
<h3><a name="tag_03_156"></a>Execution Time Monitoring</h3>
|
|
|
|
<p>A set of execution time monitoring primitives that allow online measuring of thread and process execution times.</p>
|
|
|
|
<h3><a name="tag_03_157"></a>Expand</h3>
|
|
|
|
<p>In the shell command language, when not qualified, the act of applying word expansions. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Word Expansions are defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_06">Section 2.6, Word Expansions</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_158"></a>Extended Regular Expression (ERE)</h3>
|
|
|
|
<p>A regular expression (see also <a href="#tag_03_316">Regular Expression</a> ) that is an alternative to the Basic Regular
|
|
Expression using a more extensive syntax, occasionally used by some utilities. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Extended Regular Expressions are described in detail in <a href="xbd_chap09.html#tag_09_04"><i>Extended Regular
|
|
Expressions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_159"></a>Extended Security Controls</h3>
|
|
|
|
<p>Implementation-defined security controls allowed by the file access permission and appropriate privilege (see also <a href=
|
|
"#tag_03_19">Appropriate Privileges</a> ) mechanisms, through which an implementation can support different security policies from
|
|
those described in IEEE Std 1003.1-2001. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also Extended Security Controls defined in <a href="xbd_chap04.html#tag_04_03"><i>Extended Security Controls</i></a> .
|
|
|
|
<p>File Access Permissions are defined in detail in <a href="xbd_chap04.html#tag_04_04"><i>File Access Permissions</i></a> .</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_160"></a>Feature Test Macro</h3>
|
|
|
|
<p>A macro used to determine whether a particular set of features is included from a header. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also the System Interfaces volume of IEEE Std 1003.1-2001, <a href="../functions/xsh_chap02_02.html">Section 2.2,
|
|
The Compilation Environment</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_161"></a>Field</h3>
|
|
|
|
<p>In the shell command language, a unit of text that is the result of parameter expansion, arithmetic expansion, command
|
|
substitution, or field splitting. During command processing, the resulting fields are used as the command name and its arguments.
|
|
<basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Parameter Expansion is defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_06_02">Section 2.6.2, Parameter Expansion</a>.
|
|
|
|
<p>Arithmetic Expansion is defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_06_04">Section 2.6.4, Arithmetic Expansion</a>.</p>
|
|
|
|
<p>Command Substitution is defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_06_03">Section 2.6.3, Command Substitution</a>.</p>
|
|
|
|
<p>Field Splitting is defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_06_05">Section 2.6.5, Field Splitting</a>.</p>
|
|
|
|
<p>For further information on command processing, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_09_01">Section 2.9.1, Simple Commands</a>.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_162"></a>FIFO Special File (or FIFO)</h3>
|
|
|
|
<p>A type of file with the property that data written to such a file is read on a first-in-first-out basis. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Other characteristics of FIFOs are described in the System Interfaces volume of IEEE Std 1003.1-2001, <a href=
|
|
"../functions/lseek.html"><i>lseek</i>()</a>, <a href="../functions/open.html"><i>open</i>()</a>, <a href=
|
|
"../functions/read.html"><i>read</i>()</a>, and <a href="../functions/write.html"><i>write</i>()</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_163"></a>File</h3>
|
|
|
|
<p>An object that can be written to, or read from, or both. A file has certain attributes, including access permissions and type.
|
|
File types include regular file, character special file, block special file, FIFO special file, symbolic link, socket, and
|
|
directory. Other types of files may be supported by the implementation.</p>
|
|
|
|
<h3><a name="tag_03_164"></a>File Description</h3>
|
|
|
|
<p>See <i>Open File Description</i> in <a href="#tag_03_253">Open File Description</a> .</p>
|
|
|
|
<h3><a name="tag_03_165"></a>File Descriptor</h3>
|
|
|
|
<p>A per-process unique, non-negative integer used to identify an open file for the purpose of file access. The value of a file
|
|
descriptor is from zero to {OPEN_MAX}. A process can have no more than {OPEN_MAX} file descriptors open simultaneously. File
|
|
descriptors may also be used to implement message catalog descriptors and directory streams; see also <a href="#tag_03_253">Open
|
|
File Description</a> . <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>{OPEN_MAX} is defined in detail in <a href="limits.h.html"><i><limits.h></i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_166"></a>File Group Class</h3>
|
|
|
|
<p>The property of a file indicating access permissions for a process related to the group identification of a process. A process
|
|
is in the file group class of a file if the process is not in the file owner class and if the effective group ID or one of the
|
|
supplementary group IDs of the process matches the group ID associated with the file. Other members of the class may be
|
|
implementation-defined.</p>
|
|
|
|
<h3><a name="tag_03_167"></a>File Mode</h3>
|
|
|
|
<p>An object containing the file mode bits and file type of a file. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File mode bits and file types are defined in detail in <a href="sys/stat.h.html"><i><sys/stat.h></i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_168"></a>File Mode Bits</h3>
|
|
|
|
<p>A file's file permission bits: set-user-ID-on-execution bit (S_ISUID), set-group-ID-on-execution bit (S_ISGID), and, on
|
|
directories, the restricted deletion flag bit (S_ISVTX). <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File Mode Bits are defined in detail in <a href="sys/stat.h.html"><i><sys/stat.h></i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_169"></a>Filename</h3>
|
|
|
|
<p>A name consisting of 1 to {NAME_MAX} bytes used to name a file. The characters composing the name may be selected from the set
|
|
of all character values excluding the slash character and the null byte. The filenames dot and dot-dot have special meaning. A
|
|
filename is sometimes referred to as a "pathname component". <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Pathname Resolution is defined in detail in <a href="xbd_chap04.html#tag_04_11"><i>Pathname Resolution</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_170"></a>Filename Portability</h3>
|
|
|
|
<p>Filenames should be constructed from the portable filename character set because the use of other characters can be confusing or
|
|
ambiguous in certain contexts. (For example, the use of a colon ( <tt>':'</tt> ) in a pathname could cause ambiguity if that
|
|
pathname were included in a <i>PATH</i> definition.)</p>
|
|
|
|
<h3><a name="tag_03_171"></a>File Offset</h3>
|
|
|
|
<p>The byte position in the file where the next I/O operation begins. Each open file description associated with a regular file,
|
|
block special file, or directory has a file offset. A character special file that does not refer to a terminal device may have a
|
|
file offset. There is no file offset specified for a pipe or FIFO.</p>
|
|
|
|
<h3><a name="tag_03_172"></a>File Other Class</h3>
|
|
|
|
<p>The property of a file indicating access permissions for a process related to the user and group identification of a process. A
|
|
process is in the file other class of a file if the process is not in the file owner class or file group class.</p>
|
|
|
|
<h3><a name="tag_03_173"></a>File Owner Class</h3>
|
|
|
|
<p>The property of a file indicating access permissions for a process related to the user identification of a process. A process is
|
|
in the file owner class of a file if the effective user ID of the process matches the user ID of the file.</p>
|
|
|
|
<h3><a name="tag_03_174"></a>File Permission Bits</h3>
|
|
|
|
<p>Information about a file that is used, along with other information, to determine whether a process has read, write, or
|
|
execute/search permission to a file. The bits are divided into three parts: owner, group, and other. Each part is used with the
|
|
corresponding file class of processes. These bits are contained in the file mode. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File modes are defined in detail in <a href="sys/stat.h.html"><i><sys/stat.h></i></a> .
|
|
|
|
<p>File Access Permissions are defined in detail in <a href="xbd_chap04.html#tag_04_04"><i>File Access Permissions</i></a> .</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_175"></a>File Serial Number</h3>
|
|
|
|
<p>A per-file system unique identifier for a file.</p>
|
|
|
|
<h3><a name="tag_03_176"></a>File System</h3>
|
|
|
|
<p>A collection of files and certain of their attributes. It provides a name space for file serial numbers referring to those
|
|
files.</p>
|
|
|
|
<h3><a name="tag_03_177"></a>File Type</h3>
|
|
|
|
<p>See <i>File</i> in <a href="#tag_03_163">File</a> .</p>
|
|
|
|
<h3><a name="tag_03_178"></a>Filter</h3>
|
|
|
|
<p>A command whose operation consists of reading data from standard input or a list of input files and writing data to standard
|
|
output. Typically, its function is to perform some transformation on the data stream.</p>
|
|
|
|
<h3><a name="tag_03_179"></a>First Open (of a File)</h3>
|
|
|
|
<p>When a process opens a file that is not currently an open file within any process.</p>
|
|
|
|
<h3><a name="tag_03_180"></a>Flow Control</h3>
|
|
|
|
<p>The mechanism employed by a communications provider that constrains a sending entity to wait until the receiving entities can
|
|
safely receive additional data without loss.</p>
|
|
|
|
<h3><a name="tag_03_181"></a>Foreground Job</h3>
|
|
|
|
<p>See <i>Foreground Process Group</i> in <a href="#tag_03_183">Foreground Process Group (or Foreground Job)</a> .</p>
|
|
|
|
<h3><a name="tag_03_182"></a>Foreground Process</h3>
|
|
|
|
<p>A process that is a member of a foreground process group.</p>
|
|
|
|
<h3><a name="tag_03_183"></a>Foreground Process Group (or Foreground Job)</h3>
|
|
|
|
<p>A process group whose member processes have certain privileges, denied to processes in background process groups, when accessing
|
|
their controlling terminal. Each session that has established a connection with a controlling terminal has at most one process
|
|
group of the session as the foreground process group of that controlling terminal. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The General Terminal Interface is defined in detail in <a href="xbd_chap11.html#tag_11"><i>General Terminal Interface</i></a>
|
|
.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_184"></a>Foreground Process Group ID</h3>
|
|
|
|
<p>The process group ID of the foreground process group.</p>
|
|
|
|
<h3><a name="tag_03_185"></a>Form-Feed Character (<form-feed>)</h3>
|
|
|
|
<p>A character that in the output stream indicates that printing should start on the next page of an output device. It is the
|
|
character designated by <tt>'\f'</tt> in the C language. If the <form-feed> is not the first character of an output line, the
|
|
result is unspecified. It is unspecified whether this character is the exact sequence transmitted to an output device by the system
|
|
to accomplish the movement to the next page.</p>
|
|
|
|
<h3><a name="tag_03_186"></a>Graphic Character</h3>
|
|
|
|
<p>A member of the <b>graph</b> character class of the current locale. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <b>graph</b> character class is defined in detail in <a href="xbd_chap07.html#tag_07_03_01"><i>LC_CTYPE</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_187"></a>Group Database</h3>
|
|
|
|
<p>A system database of implementation-defined format that contains at least the following information for each group ID:</p>
|
|
|
|
<ul>
|
|
<li>
|
|
<p>Group name</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Numerical group ID</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>List of users allowed in the group</p>
|
|
</li>
|
|
</ul>
|
|
|
|
<p>The list of users allowed in the group is used by the <a href="../utilities/newgrp.html"><i>newgrp</i></a> utility. <basefont
|
|
size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../utilities/newgrp.html"><i>newgrp</i></a> utility is defined in detail in the Shell and Utilities volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_188"></a>Group ID</h3>
|
|
|
|
<p>A non-negative integer, which can be contained in an object of type <b>gid_t</b>, that is used to identify a group of system
|
|
users. Each system user is a member of at least one group. When the identity of a group is associated with a process, a group ID
|
|
value is referred to as a real group ID, an effective group ID, one of the supplementary group IDs, or a saved set-group-ID.</p>
|
|
|
|
<h3><a name="tag_03_189"></a>Group Name</h3>
|
|
|
|
<p>A string that is used to identify a group; see also <a href="#tag_03_187">Group Database</a> . To be portable across conforming
|
|
systems, the value is composed of characters from the portable filename character set. The hyphen should not be used as the first
|
|
character of a portable group name.</p>
|
|
|
|
<h3><a name="tag_03_190"></a>Hard Limit</h3>
|
|
|
|
<p>A system resource limitation that may be reset to a lesser or greater limit by a privileged process. A non-privileged process is
|
|
restricted to only lowering its hard limit.</p>
|
|
|
|
<h3><a name="tag_03_191"></a>Hard Link</h3>
|
|
|
|
<p>The relationship between two directory entries that represent the same file; see also <a href="#tag_03_129">Directory Entry (or
|
|
Link)</a> . The result of an execution of the <a href="../utilities/ln.html"><i>ln</i></a> utility (without the <b>-s</b> option)
|
|
or the <a href="../functions/link.html"><i>link</i>()</a> function. This term is contrasted against symbolic link; see also <a
|
|
href="#tag_03_372">Symbolic Link</a> .</p>
|
|
|
|
<h3><a name="tag_03_192"></a>Home Directory</h3>
|
|
|
|
<p>The directory specified by the <i>HOME</i> environment variable.</p>
|
|
|
|
<h3><a name="tag_03_193"></a>Host Byte Order</h3>
|
|
|
|
<p>The arrangement of bytes in any integer type when using a specific machine architecture. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Two common methods of byte ordering are big-endian and little-endian. Big-endian is a format for storage of binary data in
|
|
which the most significant byte is placed first, with the rest in descending order. Little-endian is a format for storage or
|
|
transmission of binary data in which the least significant byte is placed first, with the rest in ascending order. See also <a
|
|
href="xbd_chap04.html#tag_04_08"><i>Host and Network Byte Orders</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_194"></a>Incomplete Line</h3>
|
|
|
|
<p>A sequence of one or more non- <newline>s at the end of the file.</p>
|
|
|
|
<h3><a name="tag_03_195"></a>Inf</h3>
|
|
|
|
<p>A value representing +infinity or a value representing -infinity that can be stored in a floating type. Not all systems support
|
|
the Inf values.</p>
|
|
|
|
<h3><a name="tag_03_196"></a>Instrumented Application</h3>
|
|
|
|
<p>An application that contains at least one call to the trace point function <a href=
|
|
"../functions/posix_trace_event.html"><i>posix_trace_event</i>()</a>. Each process of an instrumented application has a mapping of
|
|
trace event names to trace event type identifiers. This mapping is used by the trace stream that is created for that process.</p>
|
|
|
|
<h3><a name="tag_03_197"></a>Interactive Shell</h3>
|
|
|
|
<p>A processing mode of the shell that is suitable for direct user interaction.</p>
|
|
|
|
<h3><a name="tag_03_198"></a>Internationalization</h3>
|
|
|
|
<p>The provision within a computer program of the capability of making itself adaptable to the requirements of different native
|
|
languages, local customs, and coded character sets.</p>
|
|
|
|
<h3><a name="tag_03_199"></a>Interprocess Communication</h3>
|
|
|
|
<p>A functionality enhancement to add a high-performance, deterministic interprocess communication facility for local
|
|
communication.</p>
|
|
|
|
<h3><a name="tag_03_200"></a>Invoke</h3>
|
|
|
|
<p>To perform command search and execution actions, except that searching for shell functions and special built-in utilities is
|
|
suppressed; see also <a href="#tag_03_154">Execute</a> . <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Command Search and Execution is defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_09_01_01">Section 2.9.1.1, Command Search and Execution</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_201"></a>Job</h3>
|
|
|
|
<p>A set of processes, comprising a shell pipeline, and any processes descended from it, that are all in the same process group.
|
|
<basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_09_02">Section 2.9.2, Pipelines</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_202"></a>Job Control</h3>
|
|
|
|
<p>A facility that allows users selectively to stop (suspend) the execution of processes and continue (resume) their execution at a
|
|
later point. The user typically employs this facility via the interactive interface jointly supplied by the terminal I/O driver and
|
|
a command interpreter.</p>
|
|
|
|
<h3><a name="tag_03_203"></a>Job Control Job ID</h3>
|
|
|
|
<p>A handle that is used to refer to a job. The job control job ID can be any of the forms shown in the following table:<br>
|
|
</p>
|
|
|
|
<center><b><a name="tagtcjh_1"></a> Table: Job Control Job ID Formats</b></center>
|
|
|
|
<center>
|
|
<table border="1" cellpadding="3" align="center">
|
|
<tr valign="top">
|
|
<th align="center">
|
|
<p class="tent"><b>Job Control</b></p>
|
|
</th>
|
|
<th align="center">
|
|
<p class="tent"><b> </b></p>
|
|
</th>
|
|
</tr>
|
|
|
|
<tr valign="top">
|
|
<th align="center">
|
|
<p class="tent"><b>Job ID</b></p>
|
|
</th>
|
|
<th align="center">
|
|
<p class="tent"><b>Meaning</b></p>
|
|
</th>
|
|
</tr>
|
|
|
|
<tr valign="top">
|
|
<td align="left">
|
|
<p class="tent">%%</p>
|
|
</td>
|
|
<td align="left">
|
|
<p class="tent">Current job.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr valign="top">
|
|
<td align="left">
|
|
<p class="tent">%+</p>
|
|
</td>
|
|
<td align="left">
|
|
<p class="tent">Current job.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr valign="top">
|
|
<td align="left">
|
|
<p class="tent">%-</p>
|
|
</td>
|
|
<td align="left">
|
|
<p class="tent">Previous job.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr valign="top">
|
|
<td align="left">
|
|
<p class="tent">%<i>n</i></p>
|
|
</td>
|
|
<td align="left">
|
|
<p class="tent">Job number <i>n</i>.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr valign="top">
|
|
<td align="left">
|
|
<p class="tent">%<i>string</i></p>
|
|
</td>
|
|
<td align="left">
|
|
<p class="tent">Job whose command begins with <i>string</i>.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr valign="top">
|
|
<td align="left">
|
|
<p class="tent">%?<i>string</i></p>
|
|
</td>
|
|
<td align="left">
|
|
<p class="tent">Job whose command contains <i>string</i>.</p>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</center>
|
|
|
|
<h3><a name="tag_03_204"></a>Last Close (of a File)</h3>
|
|
|
|
<p>When a process closes a file, resulting in the file not being an open file within any process.</p>
|
|
|
|
<h3><a name="tag_03_205"></a>Line</h3>
|
|
|
|
<p>A sequence of zero or more non- <newline>s plus a terminating <newline>.</p>
|
|
|
|
<h3><a name="tag_03_206"></a>Linger</h3>
|
|
|
|
<p>A period of time before terminating a connection, to allow outstanding data to be transferred.</p>
|
|
|
|
<h3><a name="tag_03_207"></a>Link</h3>
|
|
|
|
<p>See <i>Directory Entry</i> in <a href="#tag_03_129">Directory Entry (or Link)</a> .</p>
|
|
|
|
<h3><a name="tag_03_208"></a>Link Count</h3>
|
|
|
|
<p>The number of directory entries that refer to a particular file.</p>
|
|
|
|
<h3><a name="tag_03_209"></a>Local Customs</h3>
|
|
|
|
<p>The conventions of a geographical area or territory for such things as date, time, and currency formats.</p>
|
|
|
|
<h3><a name="tag_03_210"></a>Local Interprocess Communication (Local IPC)</h3>
|
|
|
|
<p>The transfer of data between processes in the same system.</p>
|
|
|
|
<h3><a name="tag_03_211"></a>Locale</h3>
|
|
|
|
<p>The definition of the subset of a user's environment that depends on language and cultural conventions. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Locales are defined in detail in <a href="xbd_chap07.html#tag_07"><i>Locale</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_212"></a>Localization</h3>
|
|
|
|
<p>The process of establishing information within a computer system specific to the operation of particular native languages, local
|
|
customs, and coded character sets.</p>
|
|
|
|
<h3><a name="tag_03_213"></a>Login</h3>
|
|
|
|
<p>The unspecified activity by which a user gains access to the system. Each login is associated with exactly one login name.</p>
|
|
|
|
<h3><a name="tag_03_214"></a>Login Name</h3>
|
|
|
|
<p>A user name that is associated with a login.</p>
|
|
|
|
<h3><a name="tag_03_215"></a>Map</h3>
|
|
|
|
<p>To create an association between a page-aligned range of the address space of a process and some memory object, such that a
|
|
reference to an address in that range of the address space results in a reference to the associated memory object. The mapped
|
|
memory object is not necessarily memory-resident.</p>
|
|
|
|
<h3><a name="tag_03_216"></a>Marked Message</h3>
|
|
|
|
<p>A STREAMs message on which a certain flag is set. Marking a message gives the application protocol-specific information. An
|
|
application can use <a href="../functions/ioctl.html"><i>ioctl</i>()</a> to determine whether a given message is marked. <basefont
|
|
size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/ioctl.html"><i>ioctl</i>()</a> function is defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_217"></a>Matched</h3>
|
|
|
|
<p>A state applying to a sequence of zero or more characters when the characters in the sequence correspond to a sequence of
|
|
characters defined by a basic regular expression or extended regular expression pattern. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Regular Expressions are defined in detail in <a href="xbd_chap09.html#tag_09"><i>Regular Expressions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_218"></a>Memory Mapped Files</h3>
|
|
|
|
<p>A facility to allow applications to access files as part of the address space.</p>
|
|
|
|
<h3><a name="tag_03_219"></a>Memory Object</h3>
|
|
|
|
<p>One of:</p>
|
|
|
|
<ul>
|
|
<li>
|
|
<p>A file (see <a href="#tag_03_163">File</a> )</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>A shared memory object (see <a href="#tag_03_340">Shared Memory Object</a> )</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>A typed memory object (see <a href="#tag_03_418">Typed Memory Object</a> )</p>
|
|
</li>
|
|
</ul>
|
|
|
|
<p>When used in conjunction with <a href="../functions/mmap.html"><i>mmap</i>()</a>, a memory object appears in the address space
|
|
of the calling process. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/mmap.html"><i>mmap</i>()</a> function is defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_220"></a>Memory-Resident</h3>
|
|
|
|
<p>The process of managing the implementation in such a way as to provide an upper bound on memory access times.</p>
|
|
|
|
<h3><a name="tag_03_221"></a>Message</h3>
|
|
|
|
<p>In the context of programmatic message passing, information that can be transferred between processes or threads by being added
|
|
to and removed from a message queue. A message consists of a fixed-size message buffer.</p>
|
|
|
|
<h3><a name="tag_03_222"></a>Message Catalog</h3>
|
|
|
|
<p>In the context of providing natural language messages to the user, a file or storage area containing program messages, command
|
|
prompts, and responses to prompts for a particular native language, territory, and codeset.</p>
|
|
|
|
<h3><a name="tag_03_223"></a>Message Catalog Descriptor</h3>
|
|
|
|
<p>In the context of providing natural language messages to the user, a per-process unique value used to identify an open message
|
|
catalog. A message catalog descriptor may be implemented using a file descriptor.</p>
|
|
|
|
<h3><a name="tag_03_224"></a>Message Queue</h3>
|
|
|
|
<p>In the context of programmatic message passing, an object to which messages can be added and removed. Messages may be removed in
|
|
the order in which they were added or in priority order.</p>
|
|
|
|
<h3><a name="tag_03_225"></a>Mode</h3>
|
|
|
|
<p>A collection of attributes that specifies a file's type and its access permissions. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File Access Permissions are defined in detail in <a href="xbd_chap04.html#tag_04_04"><i>File Access Permissions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_226"></a>Monotonic Clock</h3>
|
|
|
|
<p>A clock whose value cannot be set via <a href="../functions/clock_settime.html"><i>clock_settime</i>()</a> and which cannot have
|
|
negative clock jumps.</p>
|
|
|
|
<h3><a name="tag_03_227"></a>Mount Point</h3>
|
|
|
|
<p>Either the system root directory or a directory for which the <i>st_dev</i> field of structure <b>stat</b> differs from that of
|
|
its parent directory. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <b>stat</b> structure is defined in detail in <a href="sys/stat.h.html"><i><sys/stat.h></i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_228"></a>Multi-Character Collating Element</h3>
|
|
|
|
<p>A sequence of two or more characters that collate as an entity. For example, in some coded character sets, an accented character
|
|
is represented by a non-spacing accent, followed by the letter. Other examples are the Spanish elements <i>ch</i> and
|
|
<i>ll</i>.</p>
|
|
|
|
<h3><a name="tag_03_229"></a>Mutex</h3>
|
|
|
|
<p>A synchronization object used to allow multiple threads to serialize their access to shared data. The name derives from the
|
|
capability it provides; namely, mutual-exclusion. The thread that has locked a mutex becomes its owner and remains the owner until
|
|
that same thread unlocks the mutex.</p>
|
|
|
|
<h3><a name="tag_03_230"></a>Name</h3>
|
|
|
|
<p>In the shell command language, a word consisting solely of underscores, digits, and alphabetics from the portable character set.
|
|
The first character of a name is not a digit. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The Portable Character Set is defined in detail in <a href="xbd_chap06.html#tag_06_01"><i>Portable Character Set</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_231"></a>Named STREAM</h3>
|
|
|
|
<p>A STREAMS-based file descriptor that is attached to a name in the file system name space. All subsequent operations on the named
|
|
STREAM act on the STREAM that was associated with the file descriptor until the name is disassociated from the STREAM.</p>
|
|
|
|
<h3><a name="tag_03_232"></a>NaN (Not a Number)</h3>
|
|
|
|
<p>A set of values that may be stored in a floating type but that are neither Inf nor valid floating-point numbers. Not all systems
|
|
support NaN values.</p>
|
|
|
|
<h3><a name="tag_03_233"></a>Native Language</h3>
|
|
|
|
<p>A computer user's spoken or written language, such as American English, British English, Danish, Dutch, French, German, Italian,
|
|
Japanese, Norwegian, or Swedish.</p>
|
|
|
|
<h3><a name="tag_03_234"></a>Negative Response</h3>
|
|
|
|
<p>An input string that matches one of the responses acceptable to the <i>LC_MESSAGES</i> category keyword <b>noexpr</b>, matching
|
|
an extended regular expression in the current locale. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>LC_MESSAGES</i> category is defined in detail in <a href="xbd_chap07.html#tag_07_03_06"><i>LC_MESSAGES</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_235"></a>Network</h3>
|
|
|
|
<p>A collection of interconnected hosts. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The term "network" in IEEE Std 1003.1-2001 is used to refer to the network of hosts. The term "batch system" is
|
|
used to refer to the network of batch servers.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_236"></a>Network Address</h3>
|
|
|
|
<p>A network-visible identifier used to designate specific endpoints in a network. Specific endpoints on host systems have
|
|
addresses, and host systems may also have addresses.</p>
|
|
|
|
<h3><a name="tag_03_237"></a>Network Byte Order</h3>
|
|
|
|
<p>The way of representing any integer type such that, when transmitted over a network via a network endpoint, the <b>int</b> type
|
|
is transmitted as an appropriate number of octets with the most significant octet first, followed by any other octets in descending
|
|
order of significance. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>This order is more commonly known as big-endian ordering. See also <a href="xbd_chap04.html#tag_04_08"><i>Host and Network Byte
|
|
Orders</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_238"></a>Newline Character (<newline>)</h3>
|
|
|
|
<p>A character that in the output stream indicates that printing should start at the beginning of the next line. It is the
|
|
character designated by <tt>'\n'</tt> in the C language. It is unspecified whether this character is the exact sequence transmitted
|
|
to an output device by the system to accomplish the movement to the next line.</p>
|
|
|
|
<h3><a name="tag_03_239"></a>Nice Value</h3>
|
|
|
|
<p>A number used as advice to the system to alter process scheduling. Numerically smaller values give a process additional
|
|
preference when scheduling a process to run. Numerically larger values reduce the preference and make a process less likely to run.
|
|
Typically, a process with a smaller nice value runs to completion more quickly than an equivalent process with a higher nice value.
|
|
The symbol {NZERO} specifies the default nice value of the system.</p>
|
|
|
|
<h3><a name="tag_03_240"></a>Non-Blocking</h3>
|
|
|
|
<p>A property of an open file description that causes function calls involving it to return without delay when it is detected that
|
|
the requested action associated with the function call cannot be completed without unknown delay. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The exact semantics are dependent on the type of file associated with the open file description. For data reads from devices
|
|
such as ttys and FIFOs, this property causes the read to return immediately when no data was available. Similarly, for writes, it
|
|
causes the call to return immediately when the thread would otherwise be delayed in the write operation; for example, because no
|
|
space was available. For networking, it causes functions not to await protocol events (for example, acknowledgements) to occur. See
|
|
also the System Interfaces volume of IEEE Std 1003.1-2001, <a href="../functions/xsh_chap02_10.html#tag_02_10_07">Section
|
|
2.10.7, Socket I/O Mode</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_241"></a>Non-Spacing Characters</h3>
|
|
|
|
<p>A character, such as a character representing a diacritical mark in the ISO/IEC 6937:1994 standard coded character set,
|
|
which is used in combination with other characters to form composite graphic symbols.</p>
|
|
|
|
<h3><a name="tag_03_242"></a>NUL</h3>
|
|
|
|
<p>A character with all bits set to zero.</p>
|
|
|
|
<h3><a name="tag_03_243"></a>Null Byte</h3>
|
|
|
|
<p>A byte with all bits set to zero.</p>
|
|
|
|
<h3><a name="tag_03_244"></a>Null Pointer</h3>
|
|
|
|
<p>The value that is obtained by converting the number 0 into a pointer; for example, (<b>void</b> *) 0. The C language
|
|
guarantees that this value does not match that of any legitimate pointer, so it is used by many functions that return pointers to
|
|
indicate an error.</p>
|
|
|
|
<h3><a name="tag_03_245"></a>Null String</h3>
|
|
|
|
<p>See <i>Empty String</i> in <a href="#tag_03_145">Empty String (or Null String)</a> .</p>
|
|
|
|
<h3><a name="tag_03_246"></a>Null Wide-Character Code</h3>
|
|
|
|
<p>A wide-character code with all bits set to zero.</p>
|
|
|
|
<h3><a name="tag_03_247"></a>Number Sign</h3>
|
|
|
|
<p>The character <tt>'#'</tt> , also known as hash sign.</p>
|
|
|
|
<h3><a name="tag_03_248"></a>Object File</h3>
|
|
|
|
<p>A regular file containing the output of a compiler, formatted as input to a linkage editor for linking with other object files
|
|
into an executable form. The methods of linking are unspecified and may involve the dynamic linking of objects at runtime. The
|
|
internal format of an object file is unspecified, but a conforming application cannot assume an object file is a text file.</p>
|
|
|
|
<h3><a name="tag_03_249"></a>Octet</h3>
|
|
|
|
<p>Unit of data representation that consists of eight contiguous bits.</p>
|
|
|
|
<h3><a name="tag_03_250"></a>Offset Maximum</h3>
|
|
|
|
<p>An attribute of an open file description representing the largest value that can be used as a file offset.</p>
|
|
|
|
<h3><a name="tag_03_251"></a>Opaque Address</h3>
|
|
|
|
<p>An address such that the entity making use of it requires no details about its contents or format.</p>
|
|
|
|
<h3><a name="tag_03_252"></a>Open File</h3>
|
|
|
|
<p>A file that is currently associated with a file descriptor.</p>
|
|
|
|
<h3><a name="tag_03_253"></a>Open File Description</h3>
|
|
|
|
<p>A record of how a process or group of processes is accessing a file. Each file descriptor refers to exactly one open file
|
|
description, but an open file description can be referred to by more than one file descriptor. The file offset, file status, and
|
|
file access modes are attributes of an open file description.</p>
|
|
|
|
<h3><a name="tag_03_254"></a>Operand</h3>
|
|
|
|
<p>An argument to a command that is generally used as an object supplying information to a utility necessary to complete its
|
|
processing. Operands generally follow the options in a command line. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Utility Argument Syntax is defined in detail in <a href="xbd_chap12.html#tag_12_01"><i>Utility Argument Syntax</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_255"></a>Operator</h3>
|
|
|
|
<p>In the shell command language, either a control operator or a redirection operator.</p>
|
|
|
|
<h3><a name="tag_03_256"></a>Option</h3>
|
|
|
|
<p>An argument to a command that is generally used to specify changes in the utility's default behavior. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Utility Argument Syntax is defined in detail in <a href="xbd_chap12.html#tag_12_01"><i>Utility Argument Syntax</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_257"></a>Option-Argument</h3>
|
|
|
|
<p>A parameter that follows certain options. In some cases an option-argument is included within the same argument string as the
|
|
option-in most cases it is the next argument. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Utility Argument Syntax is defined in detail in <a href="xbd_chap12.html#tag_12_01"><i>Utility Argument Syntax</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_258"></a>Orientation</h3>
|
|
|
|
<p>A stream has one of three orientations: unoriented, byte-oriented, or wide-oriented. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the System Interfaces volume of IEEE Std 1003.1-2001, <a href=
|
|
"../functions/xsh_chap02_05.html#tag_02_05_02">Section 2.5.2, Stream Orientation and Encoding Rules</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_259"></a>Orphaned Process Group</h3>
|
|
|
|
<p>A process group in which the parent of every member is either itself a member of the group or is not a member of the group's
|
|
session.</p>
|
|
|
|
<h3><a name="tag_03_260"></a>Page</h3>
|
|
|
|
<p>The granularity of process memory mapping or locking.</p>
|
|
|
|
<p>Physical memory and memory objects can be mapped into the address space of a process on page boundaries and in integral
|
|
multiples of pages. Process address space can be locked into memory (made memory-resident) on page boundaries and in integral
|
|
multiples of pages.</p>
|
|
|
|
<h3><a name="tag_03_261"></a>Page Size</h3>
|
|
|
|
<p>The size, in bytes, of the system unit of memory allocation, protection, and mapping. On systems that have segment rather than
|
|
page-based memory architectures, the term "page" means a segment.</p>
|
|
|
|
<h3><a name="tag_03_262"></a>Parameter</h3>
|
|
|
|
<p>In the shell command language, an entity that stores values. There are three types of parameters: variables (named parameters),
|
|
positional parameters, and special parameters. Parameter expansion is accomplished by introducing a parameter with the <tt>'$'</tt>
|
|
character. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_05">Section 2.5, Parameters and Variables</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<p>In the C language, 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.</p>
|
|
|
|
<h3><a name="tag_03_263"></a>Parent Directory</h3>
|
|
|
|
<p>When discussing a given directory, the directory that both contains a directory entry for the given directory and is represented
|
|
by the pathname dot-dot in the given directory.</p>
|
|
|
|
<p>When discussing other types of files, a directory containing a directory entry for the file under discussion.</p>
|
|
|
|
<p>This concept does not apply to dot and dot-dot.</p>
|
|
|
|
<h3><a name="tag_03_264"></a>Parent Process</h3>
|
|
|
|
<p>The process which created (or inherited) the process under discussion.</p>
|
|
|
|
<h3><a name="tag_03_265"></a>Parent Process ID</h3>
|
|
|
|
<p>An attribute of a new process identifying the parent of the process. The parent process ID of a process is the process ID of its
|
|
creator, for the lifetime of the creator. After the creator's lifetime has ended, the parent process ID is the process ID of an
|
|
implementation-defined system process.</p>
|
|
|
|
<h3><a name="tag_03_266"></a>Pathname</h3>
|
|
|
|
<p>A character string that is used to identify a file. In the context of IEEE Std 1003.1-2001, a pathname consists of, at
|
|
most, {PATH_MAX} bytes, including the terminating null byte. It has an optional beginning slash, followed by zero or more filenames
|
|
separated by slashes. A pathname may optionally contain one or more trailing slashes. Multiple successive slashes are considered to
|
|
be the same as one slash. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Pathname Resolution is defined in detail in <a href="xbd_chap04.html#tag_04_11"><i>Pathname Resolution</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_267"></a>Pathname Component</h3>
|
|
|
|
<p>See <i>Filename</i> in <a href="#tag_03_169">Filename</a> .</p>
|
|
|
|
<h3><a name="tag_03_268"></a>Path Prefix</h3>
|
|
|
|
<p>A pathname, with an optional ending slash, that refers to a directory.</p>
|
|
|
|
<h3><a name="tag_03_269"></a>Pattern</h3>
|
|
|
|
<p>A sequence of characters used either with regular expression notation or for pathname expansion, as a means of selecting various
|
|
character strings or pathnames, respectively. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Regular Expressions are defined in detail in <a href="xbd_chap09.html#tag_09"><i>Regular Expressions</i></a> .
|
|
|
|
<p>See also the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_06_06">Section 2.6.6, Pathname Expansion</a>.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<p>The syntaxes of the two types of patterns are similar, but not identical; IEEE Std 1003.1-2001 always indicates the
|
|
type of pattern being referred to in the immediate context of the use of the term.</p>
|
|
|
|
<h3><a name="tag_03_270"></a>Period</h3>
|
|
|
|
<p>The character <tt>'.'</tt> . The term "period" is contrasted with dot (see also <a href="#tag_03_135">Dot</a> ), which is used
|
|
to describe a specific directory entry.</p>
|
|
|
|
<h3><a name="tag_03_271"></a>Permissions</h3>
|
|
|
|
<p>Attributes of an object that determine the privilege necessary to access or manipulate the object. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File Access Permissions are defined in detail in <a href="xbd_chap04.html#tag_04_04"><i>File Access Permissions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_272"></a>Persistence</h3>
|
|
|
|
<p>A mode for semaphores, shared memory, and message queues requiring that the object and its state (including data, if any) are
|
|
preserved after the object is no longer referenced by any process.</p>
|
|
|
|
<p>Persistence of an object does not imply that the state of the object is maintained across a system crash or a system reboot.</p>
|
|
|
|
<h3><a name="tag_03_273"></a>Pipe</h3>
|
|
|
|
<p>An object accessed by one of the pair of file descriptors created by the <a href="../functions/pipe.html"><i>pipe</i>()</a>
|
|
function. Once created, the file descriptors can be used to manipulate it, and it behaves identically to a FIFO special file when
|
|
accessed in this way. It has no name in the file hierarchy. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/pipe.html"><i>pipe</i>()</a> function is defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_274"></a>Polling</h3>
|
|
|
|
<p>A scheduling scheme whereby the local process periodically checks until the pre-specified events (for example, read, write) have
|
|
occurred.</p>
|
|
|
|
<h3><a name="tag_03_275"></a>Portable Character Set</h3>
|
|
|
|
<p>The collection of characters that are required to be present in all locales supported by conforming systems. <basefont size=
|
|
"2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The Portable Character Set is defined in detail in <a href="xbd_chap06.html#tag_06_01"><i>Portable Character Set</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<p>This term is contrasted against the smaller portable filename character set; see also <a href="#tag_03_276">Portable Filename
|
|
Character Set</a> .</p>
|
|
|
|
<h3><a name="tag_03_276"></a>Portable Filename Character Set</h3>
|
|
|
|
<p>The set of characters from which portable filenames are constructed.</p>
|
|
|
|
<blockquote>
|
|
<pre>
|
|
<tt>A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
|
|
a b c d e f g h i j k l m n o p q r s t u v w x y z
|
|
0 1 2 3 4 5 6 7 8 9 . _ -
|
|
</tt>
|
|
</pre>
|
|
</blockquote>
|
|
|
|
<p>The last three characters are the period, underscore, and hyphen characters, respectively.</p>
|
|
|
|
<h3><a name="tag_03_277"></a>Positional Parameter</h3>
|
|
|
|
<p>In the shell command language, a parameter denoted by a single digit or one or more digits in curly braces. <basefont size=
|
|
"2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_05_01">Section 2.5.1, Positional Parameters</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_278"></a>Preallocation</h3>
|
|
|
|
<p>The reservation of resources in a system for a particular use.</p>
|
|
|
|
<p>Preallocation does not imply that the resources are immediately allocated to that use, but merely indicates that they are
|
|
guaranteed to be available in bounded time when needed.</p>
|
|
|
|
<h3><a name="tag_03_279"></a>Preempted Process (or Thread)</h3>
|
|
|
|
<p>A running thread whose execution is suspended due to another thread becoming runnable at a higher priority.</p>
|
|
|
|
<h3><a name="tag_03_280"></a>Previous Job</h3>
|
|
|
|
<p>In the context of job control, the job that will be used as the default for the <a href="../utilities/fg.html"><i>fg</i></a> or
|
|
<a href="../utilities/bg.html"><i>bg</i></a> utilities if the current job exits. There is at most one previous job; see also <a
|
|
href="#tag_03_203">Job Control Job ID</a> .</p>
|
|
|
|
<h3><a name="tag_03_281"></a>Printable Character</h3>
|
|
|
|
<p>One of the characters included in the <b>print</b> character classification of the <i>LC_CTYPE</i> category in the current
|
|
locale. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>LC_CTYPE</i> category is defined in detail in <a href="xbd_chap07.html#tag_07_03_01"><i>LC_CTYPE</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_282"></a>Printable File</h3>
|
|
|
|
<p>A text file consisting only of the characters included in the <b>print</b> and <b>space</b> character classifications of the
|
|
<i>LC_CTYPE</i> category and the <backspace>, all in the current locale. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>LC_CTYPE</i> category is defined in detail in <a href="xbd_chap07.html#tag_07_03_01"><i>LC_CTYPE</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_283"></a>Priority</h3>
|
|
|
|
<p>A non-negative integer associated with processes or threads whose value is constrained to a range defined by the applicable
|
|
scheduling policy. Numerically higher values represent higher priorities.</p>
|
|
|
|
<h3><a name="tag_03_284"></a>Priority Band</h3>
|
|
|
|
<p>The queuing order applied to normal priority STREAMS messages. High priority STREAMS messages are not grouped by priority bands.
|
|
The only differentiation made by the STREAMS mechanism is between zero and non-zero bands, but specific protocol modules may
|
|
differentiate between priority bands.</p>
|
|
|
|
<h3><a name="tag_03_285"></a>Priority Inversion</h3>
|
|
|
|
<p>A condition in which a thread that is not voluntarily suspended (waiting for an event or time delay) is not running while a
|
|
lower priority thread is running. Such blocking of the higher priority thread is often caused by contention for a shared
|
|
resource.</p>
|
|
|
|
<h3><a name="tag_03_286"></a>Priority Scheduling</h3>
|
|
|
|
<p>A performance and determinism improvement facility to allow applications to determine the order in which threads that are ready
|
|
to run are granted access to processor resources.</p>
|
|
|
|
<h3><a name="tag_03_287"></a>Priority-Based Scheduling</h3>
|
|
|
|
<p>Scheduling in which the selection of a running thread is determined by the priorities of the runnable processes or threads.</p>
|
|
|
|
<h3><a name="tag_03_288"></a>Privilege</h3>
|
|
|
|
<p>See <i>Appropriate Privileges</i> in <a href="#tag_03_19">Appropriate Privileges</a> .</p>
|
|
|
|
<h3><a name="tag_03_289"></a>Process</h3>
|
|
|
|
<p>An address space with one or more threads executing within that address space, and the required system resources for those
|
|
threads. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Many of the system resources defined by IEEE Std 1003.1-2001 are shared among all of the threads within a process.
|
|
These include the process ID, the parent process ID, process group ID, session membership, real, effective, and saved set-user-ID,
|
|
real, effective, and saved set-group-ID, supplementary group IDs, current working directory, root directory, file mode creation
|
|
mask, and file descriptors.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_290"></a>Process Group</h3>
|
|
|
|
<p>A collection of processes that permits the signaling of related processes. Each process in the system is a member of a process
|
|
group that is identified by a process group ID. A newly created process joins the process group of its creator.</p>
|
|
|
|
<h3><a name="tag_03_291"></a>Process Group ID</h3>
|
|
|
|
<p>The unique positive integer identifier representing a process group during its lifetime. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also Process Group ID Reuse defined in <a href="xbd_chap04.html#tag_04_12"><i>Process ID Reuse</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_292"></a>Process Group Leader</h3>
|
|
|
|
<p>A process whose process ID is the same as its process group ID.</p>
|
|
|
|
<h3><a name="tag_03_293"></a>Process Group Lifetime</h3>
|
|
|
|
<p>A period of time that begins when a process group is created and ends when the last remaining process in the group leaves the
|
|
group, due either to the end of the last process' lifetime or to the last remaining process calling the <a href=
|
|
"../functions/setsid.html"><i>setsid</i>()</a> or <a href="../functions/setpgid.html"><i>setpgid</i>()</a> functions. <basefont
|
|
size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/setsid.html"><i>setsid</i>()</a> and <a href="../functions/setpgid.html"><i>setpgid</i>()</a>
|
|
functions are defined in detail in the System Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_294"></a>Process ID</h3>
|
|
|
|
<p>The unique positive integer identifier representing a process during its lifetime. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also Process ID Reuse defined in <a href="xbd_chap04.html#tag_04_12"><i>Process ID Reuse</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_295"></a>Process Lifetime</h3>
|
|
|
|
<p>The period of time that begins when a process is created and ends when its process ID is returned to the system. After a process
|
|
is created with a <a href="../functions/fork.html"><i>fork</i>()</a> function, it is considered active. At least one thread of
|
|
control and address space exist until it terminates. It then enters an inactive state where certain resources may be returned to
|
|
the system, although some resources, such as the process ID, are still in use. When another process executes a <a href=
|
|
"../functions/wait.html"><i>wait</i>()</a>, <a href="../functions/waitid.html"><i>waitid</i>()</a>, or <a href=
|
|
"../functions/waitpid.html"><i>waitpid</i>()</a> function for an inactive process, the remaining resources are returned to the
|
|
system. The last resource to be returned to the system is the process ID. At this time, the lifetime of the process ends. <basefont
|
|
size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/fork.html"><i>fork</i>()</a>, <a href="../functions/wait.html"><i>wait</i>()</a>, <a href=
|
|
"../functions/waitid.html"><i>waitid</i>()</a>, and <a href="../functions/waitpid.html"><i>waitpid</i>()</a> functions are defined
|
|
in detail in the System Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_296"></a>Process Memory Locking</h3>
|
|
|
|
<p>A performance improvement facility to bind application programs into the high-performance random access memory of a computer
|
|
system. This avoids potential latencies introduced by the operating system in storing parts of a program that were not recently
|
|
referenced on secondary memory devices.</p>
|
|
|
|
<h3><a name="tag_03_297"></a>Process Termination</h3>
|
|
|
|
<p>There are two kinds of process termination:</p>
|
|
|
|
<ol>
|
|
<li>
|
|
<p>Normal termination occurs by a return from <i>main</i>() or when requested with the <a href=
|
|
"../functions/exit.html"><i>exit</i>()</a> or <a href="../functions/_exit.html"><i>_exit</i>()</a> functions.</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Abnormal termination occurs when requested by the <a href="../functions/abort.html"><i>abort</i>()</a> function or when some
|
|
signals are received.</p>
|
|
</li>
|
|
</ol>
|
|
|
|
<basefont size="2">
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/_exit.html"><i>_exit</i>()</a>, <a href="../functions/abort.html"><i>abort</i>()</a>, and <a href=
|
|
"../functions/exit.html"><i>exit</i>()</a> functions are defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_298"></a>Process-To-Process Communication</h3>
|
|
|
|
<p>The transfer of data between processes.</p>
|
|
|
|
<h3><a name="tag_03_299"></a>Process Virtual Time</h3>
|
|
|
|
<p>The measurement of time in units elapsed by the system clock while a process is executing.</p>
|
|
|
|
<h3><a name="tag_03_300"></a>Program</h3>
|
|
|
|
<p>A prepared sequence of instructions to the system to accomplish a defined task. The term "program" in
|
|
IEEE Std 1003.1-2001 encompasses applications written in the Shell Command Language, complex utility input languages (for
|
|
example, <a href="../utilities/awk.html"><i>awk</i></a>, <a href="../utilities/lex.html"><i>lex</i></a>, <a href=
|
|
"../utilities/sed.html"><i>sed</i></a>, and so on), and high-level languages.</p>
|
|
|
|
<h3><a name="tag_03_301"></a>Protocol</h3>
|
|
|
|
<p>A set of semantic and syntactic rules for exchanging information.</p>
|
|
|
|
<h3><a name="tag_03_302"></a>Pseudo-Terminal</h3>
|
|
|
|
<p>A facility that provides an interface that is identical to the terminal subsystem. A pseudo-terminal is composed of two devices:
|
|
the "master device" and a "slave device". The slave device provides processes with an interface that is identical to the
|
|
terminal interface, although there need not be hardware behind that interface. Anything written on the master device is presented
|
|
to the slave as an input and anything written on the slave device is presented as an input on the master side.</p>
|
|
|
|
<h3><a name="tag_03_303"></a>Radix Character</h3>
|
|
|
|
<p>The character that separates the integer part of a number from the fractional part.</p>
|
|
|
|
<h3><a name="tag_03_304"></a>Read-Only File System</h3>
|
|
|
|
<p>A file system that has implementation-defined characteristics restricting modifications. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>File Times Update is described in detail in <a href="xbd_chap04.html#tag_04_07"><i>File Times Update</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_305"></a>Read-Write Lock</h3>
|
|
|
|
<p>Multiple readers, single writer (read-write) locks allow many threads to have simultaneous read-only access to data while
|
|
allowing only one thread to have write access at any given time. They are typically used to protect data that is read-only more
|
|
frequently than it is changed.</p>
|
|
|
|
<p>Read-write locks can be used to synchronize threads in the current process and other processes if they are allocated in memory
|
|
that is writable and shared among the cooperating processes and have been initialized for this behavior.</p>
|
|
|
|
<h3><a name="tag_03_306"></a>Real Group ID</h3>
|
|
|
|
<p>The attribute of a process that, at the time of process creation, identifies the group of the user who created the process; see
|
|
also <a href="#tag_03_188">Group ID</a> .</p>
|
|
|
|
<h3><a name="tag_03_307"></a>Real Time</h3>
|
|
|
|
<p>Time measured as total units elapsed by the system clock without regard to which thread is executing.</p>
|
|
|
|
<h3><a name="tag_03_308"></a>Realtime Signal Extension</h3>
|
|
|
|
<p>A determinism improvement facility to enable asynchronous signal notifications to an application to be queued without impacting
|
|
compatibility with the existing signal functions.</p>
|
|
|
|
<h3><a name="tag_03_309"></a>Real User ID</h3>
|
|
|
|
<p>The attribute of a process that, at the time of process creation, identifies the user who created the process; see also <a href=
|
|
"#tag_03_425">User ID</a> .</p>
|
|
|
|
<h3><a name="tag_03_310"></a>Record</h3>
|
|
|
|
<p>A collection of related data units or words which is treated as a unit.</p>
|
|
|
|
<h3><a name="tag_03_311"></a>Redirection</h3>
|
|
|
|
<p>In the shell command language, a method of associating files with the input or output of commands. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_07">Section 2.7, Redirection</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_312"></a>Redirection Operator</h3>
|
|
|
|
<p>In the shell command language, a token that performs a redirection function. It is one of the following symbols:</p>
|
|
|
|
<blockquote>
|
|
<pre>
|
|
<tt>< > >| << >> <& >& <<- <>
|
|
</tt>
|
|
</pre>
|
|
</blockquote>
|
|
|
|
<h3><a name="tag_03_313"></a>Reentrant Function</h3>
|
|
|
|
<p>A function whose effect, when called by two or more threads, is guaranteed to be as if the threads each executed the function
|
|
one after another in an undefined order, even if the actual execution is interleaved.</p>
|
|
|
|
<h3><a name="tag_03_314"></a>Referenced Shared Memory Object</h3>
|
|
|
|
<p>A shared memory object that is open or has one or more mappings defined on it.</p>
|
|
|
|
<h3><a name="tag_03_315"></a>Refresh</h3>
|
|
|
|
<p>To ensure that the information on the user's terminal screen is up-to-date.</p>
|
|
|
|
<h3><a name="tag_03_316"></a>Regular Expression</h3>
|
|
|
|
<p>A pattern that selects specific strings from a set of character strings. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Regular Expressions are described in detail in <a href="xbd_chap09.html#tag_09"><i>Regular Expressions</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_317"></a>Region</h3>
|
|
|
|
<p>In the context of the address space of a process, a sequence of addresses.</p>
|
|
|
|
<p>In the context of a file, a sequence of offsets.</p>
|
|
|
|
<h3><a name="tag_03_318"></a>Regular File</h3>
|
|
|
|
<p>A file that is a randomly accessible sequence of bytes, with no further structure imposed by the system.</p>
|
|
|
|
<h3><a name="tag_03_319"></a>Relative Pathname</h3>
|
|
|
|
<p>A pathname not beginning with a slash. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Pathname Resolution is defined in detail in <a href="xbd_chap04.html#tag_04_11"><i>Pathname Resolution</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_320"></a>Relocatable File</h3>
|
|
|
|
<p>A file holding code or data suitable for linking with other object files to create an executable or a shared object file.</p>
|
|
|
|
<h3><a name="tag_03_321"></a>Relocation</h3>
|
|
|
|
<p>The process of connecting symbolic references with symbolic definitions. For example, when a program calls a function, the
|
|
associated call instruction transfers control to the proper destination address at execution.</p>
|
|
|
|
<h3><a name="tag_03_322"></a>Requested Batch Service</h3>
|
|
|
|
<p>A service that is either rejected or performed prior to a response from the service to the requester.</p>
|
|
|
|
<h3><a name="tag_03_323"></a>(Time) Resolution</h3>
|
|
|
|
<p>The minimum time interval that a clock can measure or whose passage a timer can detect.</p>
|
|
|
|
<h3><a name="tag_03_324"></a>Root Directory</h3>
|
|
|
|
<p>A directory, associated with a process, that is used in pathname resolution for pathnames that begin with a slash.</p>
|
|
|
|
<h3><a name="tag_03_325"></a>Runnable Process (or Thread)</h3>
|
|
|
|
<p>A thread that is capable of being a running thread, but for which no processor is available.</p>
|
|
|
|
<h3><a name="tag_03_326"></a>Running Process (or Thread)</h3>
|
|
|
|
<p>A thread currently executing on a processor. On multi-processor systems there may be more than one such thread in a system at a
|
|
time.</p>
|
|
|
|
<h3><a name="tag_03_327"></a>Saved Resource Limits</h3>
|
|
|
|
<p>An attribute of a process that provides some flexibility in the handling of unrepresentable resource limits, as described in the
|
|
<i>exec</i> family of functions and <a href="../functions/setrlimit.html"><i>setrlimit</i>()</a>. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>exec</i> and <a href="../functions/setrlimit.html"><i>setrlimit</i>()</a> functions are defined in detail in the System
|
|
Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_328"></a>Saved Set-Group-ID</h3>
|
|
|
|
<p>An attribute of a process that allows some flexibility in the assignment of the effective group ID attribute, as described in
|
|
the <i>exec</i> family of functions and <a href="../functions/setgid.html"><i>setgid</i>()</a>. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>exec</i> and <a href="../functions/setgid.html"><i>setgid</i>()</a> functions are defined in detail in the System
|
|
Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_329"></a>Saved Set-User-ID</h3>
|
|
|
|
<p>An attribute of a process that allows some flexibility in the assignment of the effective user ID attribute, as described in the
|
|
<i>exec</i> family of functions and <a href="../functions/setuid.html"><i>setuid</i>()</a>. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <i>exec</i> and <a href="../functions/setuid.html"><i>setuid</i>()</a> functions are defined in detail in the System
|
|
Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_330"></a>Scheduling</h3>
|
|
|
|
<p>The application of a policy to select a runnable process or thread to become a running process or thread, or to alter one or
|
|
more of the thread lists.</p>
|
|
|
|
<h3><a name="tag_03_331"></a>Scheduling Allocation Domain</h3>
|
|
|
|
<p>The set of processors on which an individual thread can be scheduled at any given time.</p>
|
|
|
|
<h3><a name="tag_03_332"></a>Scheduling Contention Scope</h3>
|
|
|
|
<p>A property of a thread that defines the set of threads against which that thread competes for resources.</p>
|
|
|
|
<p>For example, in a scheduling decision, threads sharing scheduling contention scope compete for processor resources. In
|
|
IEEE Std 1003.1-2001, a thread has scheduling contention scope of either PTHREAD_SCOPE_SYSTEM or
|
|
PTHREAD_SCOPE_PROCESS.</p>
|
|
|
|
<h3><a name="tag_03_333"></a>Scheduling Policy</h3>
|
|
|
|
<p>A set of rules that is used to determine the order of execution of processes or threads to achieve some goal. <basefont size=
|
|
"2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Scheduling Policy is defined in detail in <a href="xbd_chap04.html#tag_04_13"><i>Scheduling Policy</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_334"></a>Screen</h3>
|
|
|
|
<p>A rectangular region of columns and lines on a terminal display. A screen may be a portion of a physical display device or may
|
|
occupy the entire physical area of the display device.</p>
|
|
|
|
<h3><a name="tag_03_335"></a>Scroll</h3>
|
|
|
|
<p>To move the representation of data vertically or horizontally relative to the terminal screen. There are two types of
|
|
scrolling:</p>
|
|
|
|
<ol>
|
|
<li>
|
|
<p>The cursor moves with the data.</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>The cursor remains stationary while the data moves.</p>
|
|
</li>
|
|
</ol>
|
|
|
|
<h3><a name="tag_03_336"></a>Semaphore</h3>
|
|
|
|
<p>A minimum synchronization primitive to serve as a basis for more complex synchronization mechanisms to be defined by the
|
|
application program. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Semaphores are defined in detail in <a href="xbd_chap04.html#tag_04_15"><i>Semaphore</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_337"></a>Session</h3>
|
|
|
|
<p>A collection of process groups established for job control purposes. Each process group is a member of a session. A process is
|
|
considered to be a member of the session of which its process group is a member. A newly created process joins the session of its
|
|
creator. A process can alter its session membership; see <a href="../functions/setsid.html"><i>setsid</i>()</a>. There can be
|
|
multiple process groups in the same session. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/setsid.html"><i>setsid</i>()</a> function is defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_338"></a>Session Leader</h3>
|
|
|
|
<p>A process that has created a session. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the <a href="../functions/setsid.html"><i>setsid</i>()</a> function defined in the System
|
|
Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_339"></a>Session Lifetime</h3>
|
|
|
|
<p>The period between when a session is created and the end of the lifetime of all the process groups that remain as members of the
|
|
session.</p>
|
|
|
|
<h3><a name="tag_03_340"></a>Shared Memory Object</h3>
|
|
|
|
<p>An object that represents memory that can be mapped concurrently into the address space of more than one process.</p>
|
|
|
|
<h3><a name="tag_03_341"></a>Shell</h3>
|
|
|
|
<p>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.</p>
|
|
|
|
<h3><a name="tag_03_342"></a>Shell, the</h3>
|
|
|
|
<p>The Shell Command Language Interpreter; a specific instance of a shell. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the <a href="../utilities/sh.html"><i>sh</i></a> utility defined in the Shell and Utilities volume
|
|
of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_343"></a>Shell Script</h3>
|
|
|
|
<p>A file containing shell commands. If the file is made executable, it can be executed by specifying its name as a simple command.
|
|
Execution of a shell script causes a shell to execute the commands within the script. Alternatively, a shell can be requested to
|
|
execute the commands in a shell script by specifying the name of the shell script as the operand to the <a href=
|
|
"../utilities/sh.html"><i>sh</i></a> utility. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Simple Commands are defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_09_01">Section 2.9.1, Simple Commands</a>.
|
|
|
|
<p>The <a href="../utilities/sh.html"><i>sh</i></a> utility is defined in detail in the Shell and Utilities volume of
|
|
IEEE Std 1003.1-2001.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_344"></a>Signal</h3>
|
|
|
|
<p>A mechanism by which a process or thread 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.</p>
|
|
|
|
<h3><a name="tag_03_345"></a>Signal Stack</h3>
|
|
|
|
<p>Memory established for a thread, in which signal handlers catching signals sent to that thread are executed.</p>
|
|
|
|
<h3><a name="tag_03_346"></a>Single-Quote</h3>
|
|
|
|
<p>The character <tt>'"</tt> , also known as apostrophe.</p>
|
|
|
|
<h3><a name="tag_03_347"></a>Slash</h3>
|
|
|
|
<p>The character <tt>'/'</tt> , also known as solidus.</p>
|
|
|
|
<h3><a name="tag_03_348"></a>Socket</h3>
|
|
|
|
<p>A file of a particular type that is used as a communications endpoint for process-to-process communication as described in the
|
|
System Interfaces volume of IEEE Std 1003.1-2001.</p>
|
|
|
|
<h3><a name="tag_03_349"></a>Socket Address</h3>
|
|
|
|
<p>An address associated with a socket or remote endpoint, including an address family identifier and addressing information
|
|
specific to that address family. The address may include multiple parts, such as a network address associated with a host system
|
|
and an identifier for a specific endpoint.</p>
|
|
|
|
<h3><a name="tag_03_350"></a>Soft Limit</h3>
|
|
|
|
<p>A resource limitation established for each process that the process may set to any value less than or equal to the hard
|
|
limit.</p>
|
|
|
|
<h3><a name="tag_03_351"></a>Source Code</h3>
|
|
|
|
<p>When dealing with the Shell Command Language, input to the command language interpreter. The term "shell script" is synonymous
|
|
with this meaning.</p>
|
|
|
|
<p>When dealing with an ISO/IEC-conforming programming language, source code is input to a compiler conforming to that ISO/IEC
|
|
standard.</p>
|
|
|
|
<p>Source code also refers to the input statements prepared for the following standard utilities: <a href=
|
|
"../utilities/awk.html"><i>awk</i></a>, <a href="../utilities/bc.html"><i>bc</i></a>, <a href="../utilities/ed.html"><i>ed</i></a>,
|
|
<a href="../utilities/lex.html"><i>lex</i></a>, <a href="../utilities/localedef.html"><i>localedef</i></a>, <a href=
|
|
"../utilities/make.html"><i>make</i></a>, <a href="../utilities/sed.html"><i>sed</i></a>, and <a href=
|
|
"../utilities/yacc.html"><i>yacc</i></a>.</p>
|
|
|
|
<p>Source code can also refer to a collection of sources meeting any or all of these meanings. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../utilities/awk.html"><i>awk</i></a>, <a href="../utilities/bc.html"><i>bc</i></a>, <a href=
|
|
"../utilities/ed.html"><i>ed</i></a>, <a href="../utilities/lex.html"><i>lex</i></a>, <a href=
|
|
"../utilities/localedef.html"><i>localedef</i></a>, <a href="../utilities/make.html"><i>make</i></a>, <a href=
|
|
"../utilities/sed.html"><i>sed</i></a>, and <a href="../utilities/yacc.html"><i>yacc</i></a> utilities are defined in detail in the
|
|
Shell and Utilities volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_352"></a>Space Character (<space>)</h3>
|
|
|
|
<p>The character defined in the portable character set as <space>. The <space> is a member of the <b>space</b>
|
|
character class of the current locale, but represents the single character, and not all of the possible members of the class; see
|
|
also <a href="#tag_03_431">White Space</a> .</p>
|
|
|
|
<h3><a name="tag_03_353"></a>Spawn</h3>
|
|
|
|
<p>A process creation primitive useful for systems that have difficulty with <a href="../functions/fork.html"><i>fork</i>()</a> and
|
|
as an efficient replacement for <a href="../functions/fork.html"><i>fork</i>()</a>/ <i>exec</i>.</p>
|
|
|
|
<h3><a name="tag_03_354"></a>Special Built-In</h3>
|
|
|
|
<p>See <i>Built-In Utility</i> in <a href="#tag_03_83">Built-In Utility (or Built-In)</a> .</p>
|
|
|
|
<h3><a name="tag_03_355"></a>Special Parameter</h3>
|
|
|
|
<p>In the shell command language, a parameter named by a single character from the following list:</p>
|
|
|
|
<blockquote>
|
|
<pre>
|
|
<tt>* @ # ? ! - $ 0
|
|
</tt>
|
|
</pre>
|
|
</blockquote>
|
|
|
|
<basefont size="2">
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_05_02">Section 2.5.2, Special Parameters</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_356"></a>Spin Lock</h3>
|
|
|
|
<p>A synchronization object used to allow multiple threads to serialize their access to shared data.</p>
|
|
|
|
<h3><a name="tag_03_357"></a>Sporadic Server</h3>
|
|
|
|
<p>A scheduling policy for threads and processes that reserves a certain amount of execution capacity for processing aperiodic
|
|
events at a given priority level.</p>
|
|
|
|
<h3><a name="tag_03_358"></a>Standard Error</h3>
|
|
|
|
<p>An output stream usually intended to be used for diagnostic messages.</p>
|
|
|
|
<h3><a name="tag_03_359"></a>Standard Input</h3>
|
|
|
|
<p>An input stream usually intended to be used for primary data input.</p>
|
|
|
|
<h3><a name="tag_03_360"></a>Standard Output</h3>
|
|
|
|
<p>An output stream usually intended to be used for primary data output.</p>
|
|
|
|
<h3><a name="tag_03_361"></a>Standard Utilities</h3>
|
|
|
|
<p>The utilities described in the Shell and Utilities volume of IEEE Std 1003.1-2001.</p>
|
|
|
|
<h3><a name="tag_03_362"></a>Stream</h3>
|
|
|
|
<p>Appearing in lowercase, a stream is a file access object that allows access to an ordered sequence of characters, as described
|
|
by the ISO C standard. Such objects can be created by the <a href="../functions/fdopen.html"><i>fdopen</i>()</a>, <a href=
|
|
"../functions/fopen.html"><i>fopen</i>()</a>, or <a href="../functions/popen.html"><i>popen</i>()</a> functions, and are associated
|
|
with a file descriptor. A stream provides the additional services of user-selectable buffering and formatted input and output; see
|
|
also <a href="#tag_03_363">STREAM</a> . <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the System Interfaces volume of IEEE Std 1003.1-2001, <a href=
|
|
"../functions/xsh_chap02_05.html">Section 2.5, Standard I/O Streams</a>.
|
|
|
|
<p>The <a href="../functions/fdopen.html"><i>fdopen</i>()</a>, <a href="../functions/fopen.html"><i>fopen</i>()</a>, or <a href=
|
|
"../functions/popen.html"><i>popen</i>()</a> functions are defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_363"></a>STREAM</h3>
|
|
|
|
<p>Appearing in uppercase, STREAM refers to a full-duplex connection between a process and an open device or pseudo-device. It
|
|
optionally includes one or more intermediate processing modules that are interposed between the process end of the STREAM and the
|
|
device driver (or pseudo-device driver) end of the STREAM; see also <a href="#tag_03_362">Stream</a> . <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the System Interfaces volume of IEEE Std 1003.1-2001, <a href=
|
|
"../functions/xsh_chap02_06.html">Section 2.6, STREAMS</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_364"></a>STREAM End</h3>
|
|
|
|
<p>The STREAM end is the driver end of the STREAM and is also known as the downstream end of the STREAM.</p>
|
|
|
|
<h3><a name="tag_03_365"></a>STREAM Head</h3>
|
|
|
|
<p>The STREAM head is the beginning of the STREAM and is at the boundary between the system and the application process. This is
|
|
also known as the upstream end of the STREAM.</p>
|
|
|
|
<h3><a name="tag_03_366"></a>STREAMS Multiplexor</h3>
|
|
|
|
<p>A driver with multiple STREAMS connected to it. Multiplexing with STREAMS connected above is referred to as N-to-1, or "upper
|
|
multiplexing". Multiplexing with STREAMS connected below is referred to as 1-to-N or "lower multiplexing".</p>
|
|
|
|
<h3><a name="tag_03_367"></a>String</h3>
|
|
|
|
<p>A contiguous sequence of bytes terminated by and including the first null byte.</p>
|
|
|
|
<h3><a name="tag_03_368"></a>Subshell</h3>
|
|
|
|
<p>A shell execution environment, distinguished from the main or current shell execution environment. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_12">Section 2.12, Shell Execution Environment</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_369"></a>Successfully Transferred</h3>
|
|
|
|
<p>For a write operation to a regular file, when the system ensures that all data written is readable on any subsequent open of the
|
|
file (even one that follows a system or power failure) in the absence of a failure of the physical storage medium.</p>
|
|
|
|
<p>For a read operation, when an image of the data on the physical storage medium is available to the requesting process.</p>
|
|
|
|
<h3><a name="tag_03_370"></a>Supplementary Group ID</h3>
|
|
|
|
<p>An attribute of a process used in determining file access permissions. A process has up to {NGROUPS_MAX} supplementary group IDs
|
|
in addition to the effective group ID. The supplementary group IDs of a process are set to the supplementary group IDs of the
|
|
parent process when the process is created.</p>
|
|
|
|
<h3><a name="tag_03_371"></a>Suspended Job</h3>
|
|
|
|
<p>A job that has received a SIGSTOP, SIGTSTP, SIGTTIN, or SIGTTOU signal that caused the process group to stop. A suspended job is
|
|
a background job, but a background job is not necessarily a suspended job.</p>
|
|
|
|
<h3><a name="tag_03_372"></a>Symbolic Link</h3>
|
|
|
|
<p>A type of file with the property that when the file is encountered during pathname resolution, a string stored by the file is
|
|
used to modify the pathname resolution. The stored string has a length of {SYMLINK_MAX} bytes or fewer. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>Pathname Resolution is defined in detail in <a href="xbd_chap04.html#tag_04_11"><i>Pathname Resolution</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_373"></a>Synchronized Input and Output</h3>
|
|
|
|
<p>A determinism and robustness improvement mechanism to enhance the data input and output mechanisms, so that an application can
|
|
ensure that the data being manipulated is physically present on secondary mass storage devices.</p>
|
|
|
|
<h3><a name="tag_03_374"></a>Synchronized I/O Completion</h3>
|
|
|
|
<p>The state of an I/O operation that has either been successfully transferred or diagnosed as unsuccessful.</p>
|
|
|
|
<h3><a name="tag_03_375"></a>Synchronized I/O Data Integrity Completion</h3>
|
|
|
|
<p>For read, when the operation has been completed or diagnosed if unsuccessful. The read is complete only when an image of the
|
|
data has been successfully transferred to the requesting process. If there were any pending write requests affecting the data to be
|
|
read at the time that the synchronized read operation was requested, these write requests are successfully transferred prior to
|
|
reading the data.</p>
|
|
|
|
<p>For write, when the operation has been completed or diagnosed if unsuccessful. The write is complete only when the data
|
|
specified in the write request is successfully transferred and all file system information required to retrieve the data is
|
|
successfully transferred.</p>
|
|
|
|
<p>File attributes that are not necessary for data retrieval (access time, modification time, status change time) need not be
|
|
successfully transferred prior to returning to the calling process.</p>
|
|
|
|
<h3><a name="tag_03_376"></a>Synchronized I/O File Integrity Completion</h3>
|
|
|
|
<p>Identical to a synchronized I/O data integrity completion with the addition that all file attributes relative to the I/O
|
|
operation (including access time, modification time, status change time) are successfully transferred prior to returning to the
|
|
calling process.</p>
|
|
|
|
<h3><a name="tag_03_377"></a>Synchronized I/O Operation</h3>
|
|
|
|
<p>An I/O operation performed on a file that provides the application assurance of the integrity of its data and files.</p>
|
|
|
|
<h3><a name="tag_03_378"></a>Synchronous I/O Operation</h3>
|
|
|
|
<p>An I/O operation that causes the thread requesting the I/O to be blocked from further use of the processor until that I/O
|
|
operation completes. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>A synchronous I/O operation does not imply synchronized I/O data integrity completion or synchronized I/O file integrity
|
|
completion.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_379"></a>Synchronously-Generated Signal</h3>
|
|
|
|
<p>A signal that is attributable to a specific thread.</p>
|
|
|
|
<p>For example, a thread executing an illegal instruction or touching invalid memory causes a synchronously-generated signal. Being
|
|
synchronous is a property of how the signal was generated and not a property of the signal number.</p>
|
|
|
|
<h3><a name="tag_03_380"></a>System</h3>
|
|
|
|
<p>An implementation of IEEE Std 1003.1-2001.</p>
|
|
|
|
<h3><a name="tag_03_381"></a>System Crash</h3>
|
|
|
|
<p>An interval initiated by an unspecified circumstance that causes all processes (possibly other than special system processes) to
|
|
be terminated in an undefined manner, after which any changes to the state and contents of files created or written to by an
|
|
application prior to the interval are undefined, except as required elsewhere in IEEE Std 1003.1-2001.</p>
|
|
|
|
<h3><a name="tag_03_382"></a>System Console</h3>
|
|
|
|
<p>An implementation-defined device that receives messages sent by the <a href="../functions/syslog.html"><i>syslog</i>()</a>
|
|
function, and the <a href="../functions/fmtmsg.html"><i>fmtmsg</i>()</a> function when the MM_CONSOLE flat is set. <basefont size=
|
|
"2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/syslog.html"><i>syslog</i>()</a> and <a href="../functions/fmtmsg.html"><i>fmtmsg</i>()</a> functions
|
|
are defined in detail in the System Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_383"></a>System Databases</h3>
|
|
|
|
<p>An implementation provides two system databases.</p>
|
|
|
|
<p>The "group database" contains the following information for each group:</p>
|
|
|
|
<ol>
|
|
<li>
|
|
<p>Group name</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Numerical group ID</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>List of all users allowed in the group</p>
|
|
</li>
|
|
</ol>
|
|
|
|
<p>The "user database" contains the following information for each user:</p>
|
|
|
|
<ol>
|
|
<li>
|
|
<p>User name</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Numerical user ID</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Numerical group ID</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Initial working directory</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Initial user program</p>
|
|
</li>
|
|
</ol>
|
|
|
|
<p>If the initial user program field is null, the system default is used. If the initial working directory field is null, the
|
|
interpretation of that field is implementation-defined. These databases may contain other fields that are unspecified by
|
|
IEEE Std 1003.1-2001.</p>
|
|
|
|
<h3><a name="tag_03_384"></a>System Documentation</h3>
|
|
|
|
<p>All documentation provided with an implementation except for the conformance document. Electronically distributed documents for
|
|
an implementation are considered part of the system documentation.</p>
|
|
|
|
<h3><a name="tag_03_385"></a>System Process</h3>
|
|
|
|
<p>An implementation-defined object, other than a process executing an application, that has a process ID.</p>
|
|
|
|
<h3><a name="tag_03_386"></a>System Reboot</h3>
|
|
|
|
<p>An implementation-defined sequence of events that may result in the loss of transitory data; that is, data that is not saved in
|
|
permanent storage. For example, message queues, shared memory, semaphores, and processes.</p>
|
|
|
|
<h3><a name="tag_03_387"></a>System Trace Event</h3>
|
|
|
|
<p>A trace event that is generated by the implementation, in response either to a system-initiated action or to an
|
|
application-requested action, except for a call to <a href="../functions/posix_trace_event.html"><i>posix_trace_event</i>()</a>.
|
|
When supported by the implementation, a system-initiated action generates a process-independent system trace event and an
|
|
application-requested action generates a process-dependent system trace event. For a system trace event not defined by
|
|
IEEE Std 1003.1-2001, the associated trace event type identifier is derived from the implementation-defined name for this
|
|
trace event, and the associated data is of implementation-defined content and length.</p>
|
|
|
|
<h3><a name="tag_03_388"></a>System-Wide</h3>
|
|
|
|
<p>Pertaining to events occurring in all processes existing in an implementation at a given point in time.</p>
|
|
|
|
<h3><a name="tag_03_389"></a>Tab Character (<tab>)</h3>
|
|
|
|
<p>A character that in the output stream indicates that printing or displaying should start at the next horizontal tabulation
|
|
position on the current line. It is the character designated by <tt>'\t'</tt> in the C language. If the current position is at or
|
|
past the last defined horizontal tabulation position, the behavior is unspecified. It is unspecified whether this character is the
|
|
exact sequence transmitted to an output device by the system to accomplish the tabulation.</p>
|
|
|
|
<h3><a name="tag_03_390"></a>Terminal (or Terminal Device)</h3>
|
|
|
|
<p>A character special file that obeys the specifications of the general terminal interface. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The General Terminal Interface is defined in detail in <a href="xbd_chap11.html#tag_11"><i>General Terminal Interface</i></a>
|
|
.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_391"></a>Text Column</h3>
|
|
|
|
<p>A roughly rectangular block of characters capable of being laid out side-by-side next to other text columns on an output page or
|
|
terminal screen. The widths of text columns are measured in column positions.</p>
|
|
|
|
<h3><a name="tag_03_392"></a>Text File</h3>
|
|
|
|
<p>A file that contains characters organized into one or more lines. The lines do not contain NUL characters and none can exceed
|
|
{LINE_MAX} bytes in length, including the <newline>. Although IEEE Std 1003.1-2001 does not distinguish between
|
|
text files and binary files (see the ISO C standard), many utilities only produce predictable or meaningful output when
|
|
operating on text files. The standard utilities that have such restrictions always specify "text files" in their STDIN or INPUT
|
|
FILES sections.</p>
|
|
|
|
<h3><a name="tag_03_393"></a>Thread</h3>
|
|
|
|
<p>A single flow of control within a process. Each thread has its own thread ID, scheduling priority and policy, <i>errno</i>
|
|
value, thread-specific key/value bindings, and the required system resources to support a flow of control. Anything whose address
|
|
may be determined by a thread, including but not limited to static variables, storage obtained via <a href=
|
|
"../functions/malloc.html"><i>malloc</i>()</a>, directly addressable storage obtained through implementation-defined functions, and
|
|
automatic variables, are accessible to all threads in the same process. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/malloc.html"><i>malloc</i>()</a> function is defined in detail in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_394"></a>Thread ID</h3>
|
|
|
|
<p>Each thread in a process is uniquely identified during its lifetime by a value of type <b>pthread_t</b> called a thread ID.</p>
|
|
|
|
<h3><a name="tag_03_395"></a>Thread List</h3>
|
|
|
|
<p>An ordered set of runnable threads that all have the same ordinal value for their priority.</p>
|
|
|
|
<p>The ordering of threads on the list is determined by a scheduling policy or policies. The set of thread lists includes all
|
|
runnable threads in the system.</p>
|
|
|
|
<h3><a name="tag_03_396"></a>Thread-Safe</h3>
|
|
|
|
<p>A function that may be safely invoked concurrently by multiple threads. Each function defined in the System Interfaces volume of
|
|
IEEE Std 1003.1-2001 is thread-safe unless explicitly stated otherwise. Examples are any "pure" function, a function
|
|
which holds a mutex locked while it is accessing static storage, or objects shared among threads.</p>
|
|
|
|
<h3><a name="tag_03_397"></a>Thread-Specific Data Key</h3>
|
|
|
|
<p>A process global handle of type <b>pthread_key_t</b> which is used for naming thread-specific data.</p>
|
|
|
|
<p>Although the same key value may be used by different threads, the values bound to the key by <a href=
|
|
"../functions/pthread_setspecific.html"><i>pthread_setspecific</i>()</a> and accessed by <a href=
|
|
"../functions/pthread_getspecific.html"><i>pthread_getspecific</i>()</a> are maintained on a per-thread basis and persist for the
|
|
life of the calling thread. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../functions/pthread_getspecific.html"><i>pthread_getspecific</i>()</a> and <a href=
|
|
"../functions/pthread_setspecific.html"><i>pthread_setspecific</i>()</a> functions are defined in detail in the System Interfaces
|
|
volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_398"></a>Tilde</h3>
|
|
|
|
<p>The character <tt>'˜'</tt> .</p>
|
|
|
|
<h3><a name="tag_03_399"></a>Timeouts</h3>
|
|
|
|
<p>A method of limiting the length of time an interface will block; see also <a href="#tag_03_76">Blocked Process (or Thread)</a>
|
|
.</p>
|
|
|
|
<h3><a name="tag_03_400"></a>Timer</h3>
|
|
|
|
<p>A mechanism that can notify a thread when the time as measured by a particular clock has reached or passed a specified value, or
|
|
when a specified amount of time has passed.</p>
|
|
|
|
<h3><a name="tag_03_401"></a>Timer Overrun</h3>
|
|
|
|
<p>A condition that occurs each time a timer, for which there is already an expiration signal queued to the process, expires.</p>
|
|
|
|
<h3><a name="tag_03_402"></a>Token</h3>
|
|
|
|
<p>In the shell command language, a sequence of characters that the shell considers as a single unit when reading input. A token is
|
|
either an operator or a word. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The rules for reading input are defined in detail in the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_03">Section 2.3, Token Recognition</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_403"></a>Trace Analyzer Process</h3>
|
|
|
|
<p>A process that extracts trace events from a trace stream to retrieve information about the behavior of an application.</p>
|
|
|
|
<h3><a name="tag_03_404"></a>Trace Controller Process</h3>
|
|
|
|
<p>A process that creates a trace stream for tracing a process.</p>
|
|
|
|
<h3><a name="tag_03_405"></a>Trace Event</h3>
|
|
|
|
<p>A data object that represents an action executed by the system, and that is recorded in a trace stream.</p>
|
|
|
|
<h3><a name="tag_03_406"></a>Trace Event Type</h3>
|
|
|
|
<p>A data object type that defines a class of trace event.</p>
|
|
|
|
<h3><a name="tag_03_407"></a>Trace Event Type Mapping</h3>
|
|
|
|
<p>A one-to-one mapping between trace event types and trace event names.</p>
|
|
|
|
<h3><a name="tag_03_408"></a>Trace Filter</h3>
|
|
|
|
<p>A filter that allows the trace controller process to specify those trace event types that are to be ignored; that is, not
|
|
generated.</p>
|
|
|
|
<h3><a name="tag_03_409"></a>Trace Generation Version</h3>
|
|
|
|
<p>A data object that is an implementation-defined character string, generated by the trace system and describing the origin and
|
|
version of the trace system.</p>
|
|
|
|
<h3><a name="tag_03_410"></a>Trace Log</h3>
|
|
|
|
<p>The flushed image of a trace stream, if the trace stream is created with a trace log.</p>
|
|
|
|
<h3><a name="tag_03_411"></a>Trace Point</h3>
|
|
|
|
<p>An action that may cause a trace event to be generated.</p>
|
|
|
|
<h3><a name="tag_03_412"></a>Trace Stream</h3>
|
|
|
|
<p>An opaque object that contains trace events plus internal data needed to interpret those trace events.</p>
|
|
|
|
<h3><a name="tag_03_413"></a>Trace Stream Identifier</h3>
|
|
|
|
<p>A handle to manage tracing operations in a trace stream.</p>
|
|
|
|
<h3><a name="tag_03_414"></a>Trace System</h3>
|
|
|
|
<p>A system that allows both system and user trace events to be generated into a trace stream. These trace events can be retrieved
|
|
later.</p>
|
|
|
|
<h3><a name="tag_03_415"></a>Traced Process</h3>
|
|
|
|
<p>A process for which at least one trace stream has been created. A traced process is also called a target process.</p>
|
|
|
|
<h3><a name="tag_03_416"></a>Tracing Status of a Trace Stream</h3>
|
|
|
|
<p>A status that describes the state of an active trace stream. The tracing status of a trace stream can be retrieved from the
|
|
trace stream attributes. An active trace stream can be in one of two states: running or suspended.</p>
|
|
|
|
<h3><a name="tag_03_417"></a>Typed Memory Name Space</h3>
|
|
|
|
<p>A system-wide name space that contains the names of the typed memory objects present in the system. It is configurable for a
|
|
given implementation.</p>
|
|
|
|
<h3><a name="tag_03_418"></a>Typed Memory Object</h3>
|
|
|
|
<p>A combination of a typed memory pool and a typed memory port. The entire contents of the pool are accessible from the port. The
|
|
typed memory object is identified through a name that belongs to the typed memory name space.</p>
|
|
|
|
<h3><a name="tag_03_419"></a>Typed Memory Pool</h3>
|
|
|
|
<p>An extent of memory with the same operational characteristics. Typed memory pools may be contained within each other.</p>
|
|
|
|
<h3><a name="tag_03_420"></a>Typed Memory Port</h3>
|
|
|
|
<p>A hardware access path to one or more typed memory pools.</p>
|
|
|
|
<h3><a name="tag_03_421"></a>Unbind</h3>
|
|
|
|
<p>Remove the association between a network address and an endpoint.</p>
|
|
|
|
<h3><a name="tag_03_422"></a>Unit Data</h3>
|
|
|
|
<p>See <i>Datagram</i> in <a href="#tag_03_123">Datagram</a> .</p>
|
|
|
|
<h3><a name="tag_03_423"></a>Upshifting</h3>
|
|
|
|
<p>The conversion of a lowercase character that has a single-character uppercase representation into this uppercase
|
|
representation.</p>
|
|
|
|
<h3><a name="tag_03_424"></a>User Database</h3>
|
|
|
|
<p>A system database of implementation-defined format that contains at least the following information for each user ID:</p>
|
|
|
|
<ul>
|
|
<li>
|
|
<p>User name</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Numerical user ID</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Initial numerical group ID</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Initial working directory</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Initial user program</p>
|
|
</li>
|
|
</ul>
|
|
|
|
<p>The initial numerical group ID is used by the <a href="../utilities/newgrp.html"><i>newgrp</i></a> utility. Any other
|
|
circumstances under which the initial values are operative are implementation-defined.</p>
|
|
|
|
<p>If the initial user program field is null, an implementation-defined program is used.</p>
|
|
|
|
<p>If the initial working directory field is null, the interpretation of that field is implementation-defined. <basefont size=
|
|
"2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>The <a href="../utilities/newgrp.html"><i>newgrp</i></a> utility is defined in detail in the Shell and Utilities volume of
|
|
IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_425"></a>User ID</h3>
|
|
|
|
<p>A non-negative integer that is used to identify a system user. When the identity of a user is associated with a process, a user
|
|
ID value is referred to as a real user ID, an effective user ID, or a saved set-user-ID.</p>
|
|
|
|
<h3><a name="tag_03_426"></a>User Name</h3>
|
|
|
|
<p>A string that is used to identify a user; see also <a href="#tag_03_424">User Database</a> . To be portable across systems
|
|
conforming to IEEE Std 1003.1-2001, the value is composed of characters from the portable filename character set. The
|
|
hyphen should not be used as the first character of a portable user name.</p>
|
|
|
|
<h3><a name="tag_03_427"></a>User Trace Event</h3>
|
|
|
|
<p>A trace event that is generated explicitly by the application as a result of a call to <a href=
|
|
"../functions/posix_trace_event.html"><i>posix_trace_event</i>()</a>.</p>
|
|
|
|
<h3><a name="tag_03_428"></a>Utility</h3>
|
|
|
|
<p>A program, excluding special built-in utilities provided as part of the Shell Command Language, that can be called by name from
|
|
a shell to perform a specific task, or related set of tasks. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information on special built-in utilities, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a
|
|
href="../utilities/xcu_chap02.html#tag_02_14">Section 2.14, Special Built-In Utilities</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_429"></a>Variable</h3>
|
|
|
|
<p>In the shell command language, a named parameter. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_05">Section 2.5, Parameters and Variables</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_430"></a>Vertical-Tab Character (<vertical-tab>)</h3>
|
|
|
|
<p>A character that in the output stream indicates that printing should start at the next vertical tabulation position. It is the
|
|
character designated by <tt>'\v'</tt> in the C language. If the current position is at or past the last defined vertical tabulation
|
|
position, the behavior is unspecified. It is unspecified whether this character is the exact sequence transmitted to an output
|
|
device by the system to accomplish the tabulation.</p>
|
|
|
|
<h3><a name="tag_03_431"></a>White Space</h3>
|
|
|
|
<p>A sequence of one or more characters that belong to the <b>space</b> character class as defined via the <i>LC_CTYPE</i> category
|
|
in the current locale.</p>
|
|
|
|
<p>In the POSIX locale, white space consists of one or more <blank>s ( <space>s and <tab>s), <newline>s,
|
|
<carriage-return>s, <form-feed>s, and <vertical-tab>s.</p>
|
|
|
|
<h3><a name="tag_03_432"></a>Wide-Character Code (C Language)</h3>
|
|
|
|
<p>An integer value corresponding to a single graphic symbol or control code. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>C Language Wide-Character Codes are defined in detail in <a href="xbd_chap06.html#tag_06_03"><i>C Language Wide-Character
|
|
Codes</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_433"></a>Wide-Character Input/Output Functions</h3>
|
|
|
|
<p>The functions that perform wide-oriented input from streams or wide-oriented output to streams: <a href=
|
|
"../functions/fgetwc.html"><i>fgetwc</i>()</a>, <a href="../functions/fgetws.html"><i>fgetws</i>()</a>, <a href=
|
|
"../functions/fputwc.html"><i>fputwc</i>()</a>, <a href="../functions/fputws.html"><i>fputws</i>()</a>, <a href=
|
|
"../functions/fwprintf.html"><i>fwprintf</i>()</a>, <a href="../functions/fwscanf.html"><i>fwscanf</i>()</a>, <a href=
|
|
"../functions/getwc.html"><i>getwc</i>()</a>, <a href="../functions/getwchar.html"><i>getwchar</i>()</a>, <a href=
|
|
"../functions/putwc.html"><i>putwc</i>()</a>, <a href="../functions/putwchar.html"><i>putwchar</i>()</a>, <a href=
|
|
"../functions/ungetwc.html"><i>ungetwc</i>()</a>, <a href="../functions/vfwprintf.html"><i>vfwprintf</i>()</a>, <a href=
|
|
"../functions/vfwscanf.html"><i>vfwscanf</i>()</a>, <a href="../functions/vwprintf.html"><i>vwprintf</i>()</a>, <a href=
|
|
"../functions/vwscanf.html"><i>vwscanf</i>()</a>, <a href="../functions/wprintf.html"><i>wprintf</i>()</a>, and <a href=
|
|
"../functions/wscanf.html"><i>wscanf</i>()</a>. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>These functions are defined in detail in the System Interfaces volume of IEEE Std 1003.1-2001.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_434"></a>Wide-Character String</h3>
|
|
|
|
<p>A contiguous sequence of wide-character codes terminated by and including the first null wide-character code.</p>
|
|
|
|
<h3><a name="tag_03_435"></a>Word</h3>
|
|
|
|
<p>In the shell command language, a token other than an operator. In some cases a word is also a portion of a word token: in the
|
|
various forms of parameter expansion, such as ${<i>name</i>-<i>word</i>}, and variable assignment, such as <i>name</i>=<i>word</i>,
|
|
the word is the portion of the token depicted by <i>word</i>. The concept of a word is no longer applicable following word
|
|
expansions-only fields remain. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>For further information, see the Shell and Utilities volume of IEEE Std 1003.1-2001, <a href=
|
|
"../utilities/xcu_chap02.html#tag_02_06_02">Section 2.6.2, Parameter Expansion</a> and the Shell and Utilities volume of
|
|
IEEE Std 1003.1-2001, <a href="../utilities/xcu_chap02.html#tag_02_06">Section 2.6, Word Expansions</a>.</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_436"></a>Working Directory (or Current Working Directory)</h3>
|
|
|
|
<p>A directory, associated with a process, that is used in pathname resolution for pathnames that do not begin with a slash.</p>
|
|
|
|
<h3><a name="tag_03_437"></a>Worldwide Portability Interface</h3>
|
|
|
|
<p>Functions for handling characters in a codeset-independent manner.</p>
|
|
|
|
<h3><a name="tag_03_438"></a>Write</h3>
|
|
|
|
<p>To output characters to a file, such as standard output or standard error. Unless otherwise stated, standard output is the
|
|
default output destination for all uses of the term "write''; see the distinction between display and write in <a href=
|
|
"#tag_03_132">Display</a> .</p>
|
|
|
|
<h3><a name="tag_03_439"></a>XSI</h3>
|
|
|
|
<p>The X/Open System Interface is the core application programming interface for C and <a href="../utilities/sh.html"><i>sh</i></a>
|
|
programming for systems conforming to the Single UNIX Specification. This is a superset of the mandatory requirements for
|
|
conformance to IEEE Std 1003.1-2001.</p>
|
|
|
|
<h3><a name="tag_03_440"></a>XSI-Conformant</h3>
|
|
|
|
<p>A system which allows an application to be built using a set of services that are consistent across all systems that conform to
|
|
IEEE Std 1003.1-2001 and that support the XSI extension. <basefont size="2"></p>
|
|
|
|
<dl>
|
|
<dt><b>Note:</b></dt>
|
|
|
|
<dd>See also <a href="xbd_chap02.html#tag_02"><i>Conformance</i></a> .</dd>
|
|
</dl>
|
|
|
|
<basefont size="3">
|
|
|
|
<h3><a name="tag_03_441"></a>Zombie Process</h3>
|
|
|
|
<p>A process that has terminated and that is deleted when its exit status has been reported to another process which is waiting for
|
|
that process to terminate.</p>
|
|
|
|
<h3><a name="tag_03_442"></a>±0</h3>
|
|
|
|
<p>The algebraic sign provides additional information about any variable that has the value zero when the representation allows the
|
|
sign to be determined.</p>
|
|
|
|
<hr size="2" noshade>
|
|
<center><font size="2"><!--footer start-->
|
|
UNIX ® is a registered Trademark of The Open Group.<br>
|
|
POSIX ® is a registered Trademark of The IEEE.<br>
|
|
[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href=
|
|
"../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>
|
|
]</font></center>
|
|
|
|
<!--footer end-->
|
|
<hr size="2" noshade>
|
|
</body>
|
|
</html>
|
|
|