Writing C Modules with XS

MIME.xs The XS Source File

The new file generated by h2xs is MIME.xs (see Listing 9 3). This is the source file for 

the XS half of the module.

Listing 9 3. MIME.xs Generated by h2xs  A  n Gnome::MIME

#include "EXTERN.h"

#include "perl.h"

#include "XSUB.h"

MODULE = Gnome::MIME            PACKAGE = Gnome::MIME

The MIME.xs file consists of two parts. The first part is a series of #include

directives:

#include "EXTERN.h"

#include "perl.h"

#include "XSUB.h"

These are passed straight through to the generated C source by xsubpp. In fact, 

xsubpp passes through all text until it hits a line that starts with a MODULE directive:

MODULE = Gnome::MIME            PACKAGE = Gnome::MIME

After this line, everything must be valid XS code, none of which is generated by h2xs.

2

Modifying Makefile.PL

The Makefile.PL generated by h2xs works right away. You can see the XS build 

process without writing any XS code:

$ perl Makefile.PL && make

Checking if your kit is complete...

Looks good

Writing Makefile for Gnome::MIME

2. Actually, there is a way to get h2xs to generate some XS code for you. If you install the C::Scan 

module from CPAN, then you can use the  x option to attempt to auto generate XS from a C 

header file. At present this process only succeeds with very simple header files. See the h2xs

documentation for more details.

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