[Pyrex] Function wrapping problems

[Bob Ippolito]

On Tuesday, Oct 14, 2003, at 17:19 America/New_York, Simon Frost wrote:

> I'm trying to wrap some C code (emitted from Eiffel using the 
> SmartEiffel compiler, not that it matters) using Pyrex, so I can call 
> the C function from Python. The C code that calls the function 
> directly is as follows:
>
> #include <stdio.h>
> #include "eiffel.h"
>
> int main(int argc, char* argv[ ])
> {
>    initialize_eiffel_runtime(argc,argv);
>    run_epidemic(eiffel_root_object);
>    return 0;
> }
>
> Here are the declarations that I (think I) need for Pyrex:
>
> cdef extern from "epidemic.h":
>   void initialize_eiffel_runtime(int argc,char* argv[])
>
> cdef extern from "eiffel.h":
>   void run_epidemic(void* C)
>   void* eiffel_root_object
>
> This question probably reflects my lack of knowledge (of both C and 
> Pyrex), but how can I reproduce my C main function within a Pyrex 
> function?

I believe that you want something like this (in addition to what you 
already have):

cdef extern from "Python.h":
	char *PyString_FromString(object s) except NULL
	void* PyMem_Realloc(void *p, int n)
	void* PyMem_Malloc(int n)
	void PyMem_Free(void *p)

def main(*args):
	cdef char **argv
	cdef int argc
	cdef int i
	argc = len(args)
	argv = PyMem_Malloc(4 * argc)
	if argv == NULL:
		raise MemoryError, "Out of memory?"
	try:
		i = 0
		for arg in args:
			argv[i] = PyString_FromString(arg)
			i = i + 1
		initialize_eiffel_runtime(argc, argv)
		run_epidemic(eiffel_root_object)
	finally:
		PyMem_Free(argv)


 From python, you would do:

	import yourmodule
	yourmodule.main('first argument', 'second argument')

-bob