What Is Socket Communication?
This section describes the socket communication model on the Internet network. A socket represents one end-point of a two-way communication link between two programs running on the Internet network.
Socket: An concept represents one end-point of a two-way communication
link between two programs running on the Internet network.
Internet Address: A unique number to identify each computer system on
Port: A number representing an entry point of on a computer system on
the Internet, where a two-way communication link can be established.
Local System: The computer system at this end of a two-way communication
Remote System: The computer system at the other end of a two-way
A two-way communication link on the Internet involves:
- Two computer systems, each has its own Internet address.
- A port number on each computer system that is used only by this
- An application program on each computer system that uses this
- A socket handle created in the application program that represents
this communication link.
- The application program can use the socket as a logical input or
output device to receive or send data from or to the application program
running at the other end of the communication link.
- The application program can also query the socket for information
about the communication link, like: The Internet address and port number
at this end of the communication link; The Internet address and port number
at the other end of the communication link.
The following diagram illustrates how an application program can use a socket
to talk with other application program running on another computer system
through a two-way communication link on the Internet:
Computer System I Computer System II
i/o |Address a| Internet |Address b| i/o
App. A<--->Socket|Port 1 |<-------------->| Port 2|Socket<--->App. B
Table of Contents
About This Book
Perl on Linux Systems
ActivePerl on Windows Systems
Data Types: Values and Variables
Expressions, Operations and Simple Statements
User Defined Subroutines
Perl Built-in Debugger
Name Spaces and Perl Module Files
Symbolic (or Soft) References
Hard References - Addresses of Memory Objects
Objects (or References) and Classes (or Packages)
Typeglob and Importing Identifiers from Other Packages
String Built-in Functions and Performance
File Handles and Data Input/Output
Open Files in Binary Mode
Open Directories and Read File Names
File System Functions and Operations
Converting Perl Script to Executable Binary
Using DBM Database Files
Using MySQL Database Server
►Socket Communication Over the Internet
►What Is Socket Communication?
connect() - Establishing a Socket Communication
ReverseEchoer.pl - A Simple Socket Server Program
SocketClient.pl - A Simple Socket Client Program
gethostbyaddr() - Network Utility Functions
Socket.pm - The Socket Module
XML::Simple Module - XML Parser and Generator
XML Communication Model
SOAP::Lite - SOAP Server-Client Communication Module
Perl Programs as IIS Server CGI Scripts
CGI (Common Gateway Interface)
XML-RPC - Remote Procedure Call with XML and HTTP
RPC::XML - Perl Implementation of XML-RPC
Integrating Perl with Apache Web Server
CGI.pm Module for Building Web Pages
LWP::UserAgent and Web Site Testing
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