subprocess to C program

[Aaron Brady]

On Dec 13, 9:09 pm, MRAB <goo... at mrabarnett.plus.com> wrote:
> Aaron Brady wrote:
> > On Dec 13, 7:51 pm, Grant Edwards <gra... at visi.com> wrote:
> >> On 2008-12-14, MRAB <goo... at mrabarnett.plus.com> wrote:
>
> >>>> I am writing a C process and I want to read data from a file that I
> >>>> write to in Python.  I'm creating a pipe in Python, passing it to the
> >>>> C process, and calling '_read'.  It gives me error 9, bad file number.
> > snip
> >>>> meaning that 'ct' is -1, 'readfd' is 3, and 'errno' is 9.  I want 'ct'
> >>>> to be 11 at this point.  Thanks in advance.
> >>> It looks like the ids aren't system global.
> >> They certainly aren't in Unix: Their a property of the process.
>
> >> --
> >> Grant
>
> > I'm not on Unix.  It has to be possible somehow.  Do I need to set
> > permissions on the IDs?  Are Stdin and Stdout my only options?  Or
> > does Popen prevent sharing IDs somehow?
>
> You'd be better off using sockets.

I got the 'stdin' solution to work.  The Python end worked fine.  I
just had to use the 'getchar' function instead of '_getch' function on
the C end.  Not obvious, I guess.  Ideally, I could block on input
from the console and stdin individually.