How do you create a Perl module?

Question

How do you write a module for Perl? In Python you can use:

# module.py
def helloworld(name):
    print \"Hello, %s\" % name

# main.py
import module
module.         


        

Answer 1

Basically you create a file named Yourmodulename.pm, whose contents are:

package Yourmodulename;

# Here are your definitions

1; # Important, every module should return a true value

Then the program that uses the module will look like:

#!/usr/bin/perl
use strict;            # These are good pragmas
use warnings;      

# Used modules
use Carp;              # A module that you'll probably find useful
use Yourmodulename;    # Your module

You may want to organize your modules in a hierarchical (and hopefully logical) way. To do so you create a tree of directories like:

Your/Module.pm
Your/Other/Module.pm

And then in your program:

use Your::Module;
use Your::Other::Module;

There are more facilities to export functions and variables from your module, you can take a look at Henning Koch's "Writing serious Perl: The absolute minimum you need to know".