Writing C Modules with XS

MIME.pm The Module File

The module file generated for an XS module is mostly the same as that for a 

Perl only module with a few additions. First, a new require is specified:

require DynaLoader;

This line pulls in the DynaLoader module that allows Perl modules to load shared 

libraries. Next, DynaLoader is added to the @ISA inheritance array:

our @ISA = qw(Exporter DynaLoader);

Inheriting from DynaLoader is the standard way to allow your module to be 

partially implemented in XS. Later in the file, the bootstrap() subroutine from 

DynaLoader is called:

bootstrap Gnome::MIME $VERSION;

This call to DynaLoader::bootstrap() finds and loads a shared library corresponding to 

Gnome::MIME. By passing $VERSION as the second argument, DynaLoader will 

check that the loaded shared library matches this version of the Perl half of the 

module. This is not a required parameter, but h2xs defaults to including it since it 

helps prevent a very common class of errors.

Listing 9 1 shows a module file generated for an XS module.

Listing 9 1. MIME.pm Generated by h2xs  A  n Gnome::MIME

package Gnome::MIME;

use 5.006;

use strict;

use warnings;

require Exporter;

require DynaLoader;

our @ISA = qw(Exporter DynaLoader);

# Items to export into callers namespace by default. Note: do not export

# names by default without a very good reason. Use EXPORT_OK instead.

# Do not simply export all your public functions/methods/constants.

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