Perl Tutorials - Herong's Tutorial Examples - Version 5.32, by Dr. Herong Yang
Accessing Identifiers from Other Packages as Aliases
This section provides a tutorial example on how to access identifiers from another package as aliases, *identifier = *package::identifier.
As we learned earlier, to access variables from other packages is to use their fully qualified names in the format of packageName::variableName. But this format is too long, and not easy to use, see the following program:
#- CalendarTest.pl #- Copyright (c) 1995 by Dr. Herong Yang, http://www.herongyang.com/ # require CalendarModule; print("Date: $CalendarModule::smon"); print(" $CalendarModule::smday"); print(" $CalendarModule::syear\n"); print("Leap year? ",&CalendarModule::isLeapYear(), "\n"); exit;
To make this easier, variables from other packages can be introduced into the current package as aliases. Here is how I improved the previous program:
#- CalendarAliasTest.pl #- Copyright (c) 1999 by Dr. Herong Yang, http://www.herongyang.com/ # require CalendarModule; *smon = *CalendarModule::smon; *smday = *CalendarModule::smday; *syear = *CalendarModule::syear; *isLeapYear = *CalendarModule::isLeapYear; print("Date: $smon"); print(" $smday"); print(" $syear\n"); print("Leap year? ",&isLeapYear(), "\n"); exit;
Table of Contents
Data Types: Values and Variables
Expressions, Operations and Simple Statements
Name Spaces and Perl Module Files
Hard References - Addresses of Memory Objects
Objects (or References) and Classes (or Packages)
►Typeglob and Importing Identifiers from Other Packages
Typeglob, Symbolic Table and Identifier Aliases
►Accessing Identifiers from Other Packages as Aliases
Exporting and Importing Package Identifiers
String Built-in Functions and Performance
File Handles and Data Input/Output
Open Directories and Read File Names
File System Functions and Operations
Converting Perl Script to Executable Binary
Socket Communication Over the Internet
XML::Simple Module - XML Parser and Generator
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