redirecting stdio

[Keith S.]

Hi,

I'm rather new to Python and am trying to embed it into a C++
application. The documentation gives the basics of this, but
I want Python's output (stdio/stderr) to be redirected to C++
functions (to display the text in a message window).

Can anyone point me to a description or example of how this is
done?

thanks,

Keith

[Alex Martelli]

Keith S. wrote:

Here's a little thing I had laying around -- not quite what
you ask, but it might help. It's a small demonstrative C
extension which does just about the bare minimum needed to
show how to redirect Python's stdout from C when imported.

#include <Python.h>
#include <stdio.h>

static PyObject*
redi(PyObject* self, PyObject* args)
{
char* thestring;
if(!PyArg_ParseTuple(args, "s", &thestring))
return 0;
printf("Print string: (%s)\n", thestring);
return Py_BuildValue("");
}

static PyMethodDef rediMethods[] = {
{"redi", redi, METH_VARARGS, "Redirect ouput"},
{0}
};

void
initredi(void)
{
PyObject* sys_module = PyImport_ImportModule("sys");
PyObject* redi_module = Py_InitModule("redi", rediMethods);
PyObject* redi_dict = PyModule_GetDict(redi_module);
PyObject* aux;
char * code = "class Sout:\n"
" def write(self, s): redi(s)\n"
"sout = Sout()\n";

aux = PyRun_String(code, Py_file_input, redi_dict, redi_dict);
Py_XDECREF(aux);
aux = PyObject_GetAttrString(redi_module, "sout");
PyObject_SetAttrString(sys_module, "stdout", aux);
Py_XDECREF(aux);
}

Alex