Cannot get pipes to work with glibmm

[Bastien Dalla Piazza <bastien dallapiazza gmail com>]

Hi,

I don't know if this is the correct mailing list so redirect me if not.

In a Gtkmm project, I'm using Glib::spawn_async_with_pipes to execute
and control a child process (gnugo in the example). But I cannot get it
to work!
For example:
In the following code, I just redirect the gnugo stdin and stdout to my
program:

#include <glibmm.h>
#include <vector>
#include <string>
#include <iostream>

int main(int argc, char** argv)
{
    Glib::init();

    int fd_stdin, fd_stdout; //file descriptors
    Glib::Pid pid;
    Glib::RefPtr<Glib::IOChannel> ch_stdin, ch_stdout;

    std::vector<std::string> arguments;
    arguments.push_back("gnugo");
    arguments.push_back("--mode");
    arguments.push_back("gtp");

    /spawn gnugo
    Glib::spawn_async_with_pipes(Glib::get_current_dir(),
                             arguments,Glib::SPAWN_SEARCH_PATH,
                             sigc::slot<void>(),
                             &pid,&fd_stdin,&fd_stdout);

    //create the IOChannel from the file descriptors
    ch_stdin=Glib::IOChannel::create_from_fd(fd_stdin);
    ch_stdout=Glib::IOChannel::create_from_fd(fd_stdout);

    Glib::ustring input,output;

    //a stupid loop to test whether the pipes work
    while(true){
        std::cin>>input;
        ch_stdin->write(input.append("\n"));
        ch_stdout->read_to_end(output);
        std::cout<<output<<std::endl;
    }
}

Any idea what I am doing wrong?

Thanks!