📄 ch24.htm
字号:
<HTML>
<HEAD>
<TITLE>Appendix B -- Glossary</TITLE>
<META>
</HEAD>
<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#0000EE" VLINK="#551A8B" ALINK="#CE2910">
<H1><FONT SIZE=6 COLOR=#FF0000>Appendix B</FONT></H1>
<H1><FONT SIZE=6 COLOR=#FF0000>Glossary</FONT></H1>
<HR>
<P>
<CENTER><B><FONT SIZE=5>CONTENTS</FONT></B></CENTER>
<UL>
<LI><A HREF="#Abstraction">
Abstraction</A>
<LI><A HREF="#Alternation">
Alternation</A>
<LI><A HREF="#AlternativeQuotes">
Alternative Quotes</A>
<LI><A HREF="#ANChor">
ANChor</A>
<LI><A HREF="#AnonymousFuNCtionsandVariables">
Anonymous FuNCtions and Variables</A>
<LI><A HREF="#ANSI">
ANSI</A>
<LI><A HREF="#Argument">
Argument</A>
<LI><A HREF="#Array">
Array</A>
<LI><A HREF="#ArrayContext">
Array Context</A>
<LI><A HREF="#ArrayRange">
Array Range</A>
<LI><A HREF="#ArraySlice">
Array Slice</A>
<LI><A HREF="#ArraySplice">
Array Splice</A>
<LI><A HREF="#ASCII">
ASCII</A>
<LI><A HREF="#Assignment">
Assignment</A>
<LI><A HREF="#AssociativeArray">
Associative Array</A>
<LI><A HREF="#Associativitylefttorightamprighttoleft">
Associativity (left-to-right & right-to-left)</A>
<LI><A HREF="#awk">
awk</A>
<LI><A HREF="#Backtracking">
Backtracking</A>
<LI><A HREF="#BinaryMode">
Binary Mode</A>
<LI><A HREF="#BitwiseOperations">
Bitwise Operations</A>
<LI><A HREF="#Block">
Block</A>
<LI><A HREF="#CallbyRefereNCe">
Call by RefereNCe</A>
<LI><A HREF="#CallbyValue">
Call by Value</A>
<LI><A HREF="#CharacterClasses">
Character Classes</A>
<LI><A HREF="#ChildProcess">
Child Process</A>
<LI><A HREF="#Class">
Class</A>
<LI><A HREF="#ClientServer">
Client/Server</A>
<LI><A HREF="#CommandLineOptions">
Command-Line Options</A>
<LI><A HREF="#Compiler">
Compiler</A>
<LI><A HREF="#CompileTimeError">
Compile-Time Error</A>
<LI><A HREF="#CoNCatenation">
CoNCatenation</A>
<LI><A HREF="#Constant">
Constant</A>
<LI><A HREF="#Constructor">
Constructor</A>
<LI><A HREF="#ContextArrayampScalar">
Context (Array & Scalar)</A>
<LI><A HREF="#ControlCharacters">
Control Characters</A>
<LI><A HREF="#CR">
CR</A>
<LI><A HREF="#Database">
Database</A>
<LI><A HREF="#DataType">
Data Type</A>
<LI><A HREF="#Debugger">
Debugger</A>
<LI><A HREF="#Declaration">
Declaration</A>
<LI><A HREF="#Deconstructor">
Deconstructor</A>
<LI><A HREF="#Defined">
Defined</A>
<LI><A HREF="#Delimiter">
Delimiter</A>
<LI><A HREF="#DerefereNCe">
DerefereNCe</A>
<LI><A HREF="#DetailLine">
Detail Line</A>
<LI><A HREF="#DiamondOperator">
Diamond Operator</A>
<LI><A HREF="#Directory">
Directory</A>
<LI><A HREF="#DottedDecimalAddress">
Dotted Decimal Address</A>
<LI><A HREF="#EmptyStringsArraysListsandHashes">
Empty Strings, Arrays, Lists, and Hashes</A>
<LI><A HREF="#ENCapsulation">
ENCapsulation</A>
<LI><A HREF="#ENCryption">
ENCryption</A>
<LI><A HREF="#EndlessLoop">
Endless Loop</A>
<LI><A HREF="#EnvironmentVariables">
Environment Variables</A>
<LI><A HREF="#EOF">
EOF</A>
<LI><A HREF="#EscapeSequeNCe">
Escape SequeNCe</A>
<LI><A HREF="#Expression">
Expression</A>
<LI><A HREF="#FF">
FF</A>
<LI><A HREF="#Field">
Field</A>
<LI><A HREF="#Filehandle">
Filehandle</A>
<LI><A HREF="#Footer">
Footer</A>
<LI><A HREF="#Formats">
Formats</A>
<LI><A HREF="#ftp">
ftp</A>
<LI><A HREF="#FuNCtion">
FuNCtion</A>
<LI><A HREF="#Globbing">
Globbing</A>
<LI><A HREF="#GreedyRegularExpressions">
Greedy Regular Expressions</A>
<LI><A HREF="#Grep">
Grep</A>
<LI><A HREF="#Hash">
Hash</A>
<LI><A HREF="#Header">
Header</A>
<LI><A HREF="#HereDocuments">
Here Documents</A>
<LI><A HREF="#Hexadecimal">
Hexadecimal</A>
<LI><A HREF="#InfiniteLoop">
Infinite Loop</A>
<LI><A HREF="#InheritaNCe">
InheritaNCe</A>
<LI><A HREF="#Initialization">
Initialization</A>
<LI><A HREF="#Interpolation">
Interpolation</A>
<LI><A HREF="#Interpreter">
Interpreter</A>
<LI><A HREF="#InterprocessCommunication">
Inter-process Communication</A>
<LI><A HREF="#IO">
I/O</A>
<LI><A HREF="#IPC">
IPC</A>
<LI><A HREF="#KeyValuePair">
Key-Value Pair</A>
<LI><A HREF="#Label">
Label</A>
<LI><A HREF="#LF">
LF</A>
<LI><A HREF="#Library">
Library</A>
<LI><A HREF="#List">
List</A>
<LI><A HREF="#Literal">
Literal</A>
<LI><A HREF="#Loop">
Loop</A>
<LI><A HREF="#MetaCharacters">
Meta Characters</A>
<LI><A HREF="#Module">
Module</A>
<LI><A HREF="#Namespace">
Namespace</A>
<LI><A HREF="#Object">
Object</A>
<LI><A HREF="#Octal">
Octal</A>
<LI><A HREF="#Operator">
Operator</A>
<LI><A HREF="#Parameter">
Parameter</A>
<LI><A HREF="#Polymorphism">
Polymorphism</A>
<LI><A HREF="#Port">
Port</A>
<LI><A HREF="#PrecedeNCe">
PrecedeNCe</A>
<LI><A HREF="#Procedure">
Procedure</A>
<LI><A HREF="#Protocol">
Protocol</A>
<LI><A HREF="#Range">
Range</A>
<LI><A HREF="#Record">
Record</A>
<LI><A HREF="#RefereNCe">
RefereNCe</A>
<LI><A HREF="#RegularExpression">
Regular Expression</A>
<LI><A HREF="#ReturnValue">
Return Value</A>
<LI><A HREF="#RunTimeError">
Run-Time Error</A>
<LI><A HREF="#Scalar">
Scalar</A>
<LI><A HREF="#ScalarContext">
Scalar Context</A>
<LI><A HREF="#Scope">
Scope</A>
<LI><A HREF="#ShortCircuitOperators">
Short-Circuit Operators</A>
<LI><A HREF="#Signals">
Signals</A>
<LI><A HREF="#Slice">
Slice</A>
<LI><A HREF="#Socket">
Socket</A>
<LI><A HREF="#Splice">
Splice</A>
<LI><A HREF="#Stack">
Stack</A>
<LI><A HREF="#Statement">
Statement</A>
<LI><A HREF="#STDERRSTDINandSTDOUT">
STDERR, STDIN, and STDOUT</A>
<LI><A HREF="#Subroutine">
Subroutine</A>
<LI><A HREF="#TextMode">
Text Mode</A>
<LI><A HREF="#UndefinedValue">
Undefined Value</A>
<LI><A HREF="#Variable">
Variable</A>
<LI><A HREF="#Whitespace">
Whitespace</A>
</UL>
<HR>
<H2><A NAME="Abstraction"><FONT SIZE=5 COLOR=#FF0000>
Abstraction</FONT></A></H2>
<P>
The priNCiple of abstraction means that information can be accessed
in a way that isolates how data is stored from how it is accessed
and used.
<BLOCKQUOTE>
See also <I>Classes</I>, <I>ENCapsulation</I>, <I>InheritaNCe</I>,
and <I>Polymorphism</I>.
</BLOCKQUOTE>
<H2><A NAME="Alternation"><FONT SIZE=5 COLOR=#FF0000>
Alternation</FONT></A></H2>
<P>
Alternation is the term used when a regular expression pattern
chooses between two or more choices. For example, <TT>m/one|two|three/</TT>
will match if the string in <TT>$_</TT>
contains any one of the three character sequeNCes: <TT>one</TT>,
<TT>two</TT>, or <TT>three</TT>.
<BLOCKQUOTE>
See also <I>Regular Expression</I>.
</BLOCKQUOTE>
<H2><A NAME="AlternativeQuotes"><FONT SIZE=5 COLOR=#FF0000>
Alternative Quotes</FONT></A></H2>
<P>
Perl has three distiNCtive types of quotes: single-quotes ('),
double-quotes ("), and back-quotes (`). If you'd like to
be a bit more explicit in quoting, you can use the alternates
that are also provided: q( ) for single-quotes, qq( )
for double-quotes, and qx( ) for back-quotes. For example,
<TT>q(This)</TT> is equivalent to
<TT>'This'</TT>. Perl also has an
alternative mechanism that can be used to quote a lot of small
single words. For example, <TT>qw(one, two,
three)</TT> is equivalent to <TT>('one',
'two', 'three')</TT>.
<H2><A NAME="ANChor"><FONT SIZE=5 COLOR=#FF0000>
ANChor</FONT></A></H2>
<P>
See <I>Pattern ANChor</I>.
<H2><A NAME="AnonymousFuNCtionsandVariables"><FONT SIZE=5 COLOR=#FF0000>
Anonymous FuNCtions and Variables</FONT></A></H2>
<P>
It is often very useful to create a fuNCtion or variable without
identifying names; these programming elements are called anonymous.
You allude to them using refereNCes. For example, if you initialize
<TT>$foo</TT> using <TT>$foo
= { 'John' => 10, 'Karen' => 20}</TT>, then <TT>$foo</TT>
becomes a refereNCe to the anonymous hash. You access the hash
entries by derefereNCing <TT>$foo</TT>.
For example, <TT>@{$foo}{'John'}</TT>
is equal to <TT>10</TT>.
<BLOCKQUOTE>
See also <I>RefereNCe </I>and <I>DerefereNCe</I>.
</BLOCKQUOTE>
<H2><A NAME="ANSI"><FONT SIZE=5 COLOR=#FF0000>
ANSI</FONT></A></H2>
<P>
ANSI refers to the American National Standards Institute. ANSI
serves to administer and coordinate the U.S. private sector voluntary
standardization system. Founded in 1918 by five engineering societies
and three government ageNCies, the Institute remains a private,
nonprofit, membership organization supported by a diverse constitueNCy
of private and public sector organizations. Its home page is <B>http://www.ansi.org/home.html</B>
and you can find many refereNCes to the different standards there.
The American National Standards Institute is located at 11 West
42<FONT SIZE=1>nd</FONT> Street, New York, NY 10036 (Telephone:
(212) 642-4900; Telefax: (212) 398-0023).
<BLOCKQUOTE>
See <I>ASCII</I>.
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -