Getting constants from *.h header files

[KKramsch]

I have a Perl extension written in C that uses several constants,
which are defined in the usual way as macros in a header (*.h)
file:

/* foobar.h */
#define FOO 1
#define BAR 2

....etc.

Is there a standard way for Perl code to access these constants?

Thanks!

-Karl

 

[Tassilo v. Parseval]

Also sprach KKramsch:

I have a Perl extension written in C that uses several constants,
which are defined in the usual way as macros in a header (*.h)
file:

/* foobar.h */
#define FOO 1
#define BAR 2

...etc.

Is there a standard way for Perl code to access these constants?

There are several possible ways. One would be running the header through
h2ph:

ethan@ethan:~$ h2ph -d . foobar.h
foobar.h -> foobar.ph
ethan@ethan:~$ perl -e 'require "foobar.ph"; print &FOO'
1

Or you could use h2xs to turn the header into a full-fledged module with
proper namespacing etc. In the latter case, the module requires
compilation before it can be used. But it is more flexible as you can
specify which of the constants are to be exported into the caller's
namespace per default, which on demand and so forth.

Tassilo

 

[Ben Morrow]

I have a Perl extension written in C that uses several constants,
which are defined in the usual way as macros in a header (*.h)
file:

/* foobar.h */
#define FOO 1
#define BAR 2

...etc.

Is there a standard way for Perl code to access these constants?

h2xs will generate constant Perl subs for you, if you ask it nicely .

Ben

 

[KKramsch]

Also sprach KKramsch:

There are several possible ways. One would be running the header through
h2ph:

ethan@ethan:~$ h2ph -d . foobar.h
foobar.h -> foobar.ph
ethan@ethan:~$ perl -e 'require "foobar.ph"; print &FOO'
1

Or you could use h2xs to turn the header into a full-fledged module with
proper namespacing etc. In the latter case, the module requires
compilation before it can be used. But it is more flexible as you can
specify which of the constants are to be exported into the caller's
namespace per default, which on demand and so forth.

Thanks!

-Karl