[C++-sig] Redirecting stdout for B.P extensions?

[Mike Rovner]

Hubert Holin wrote:
> Paris (U.E.), le 14/09/2005
>          However, were I to embed Python, I assume I could swap out  
> cout's file descriptor and both the Python scripts and subsequent C++  
> code would be none the wiser, but if instead I extend Python (as is  
> the case in my current project), I either have to find a way to  
> access the Python executable's cout file descriptor (how would I do  
> that? by using a C extension?), or have to make every script and  
> extension aware of an additional parameter (be it a pipe or whatever,  
> to redirect to) and code explicitly for that (i.e. it would not be  
> transparent at al).
> 
>          Is that correct?

It will not be transparent in either case as you depend on Python notion 
of sys.stdout.

You can access the Python executable's cout file descriptor as (untested!):

{
using namespace boost::python;

object sys(PyImport_ImportModule("sys"));
object sys_stdout = sys.attr("stdout");

if( PyFile_Check(sys_stdout.ptr()) )
{
   FILE* cout_file = PyFile_AsFile(sys_stdout.ptr());
   // ...
}
else
{
   throw PythonStdoutNotAfile();
}
}