Hi again, I partially solved my problem:
One needs to call Glib::IOChannel::flush() after writing on outgoing
pipe for the message to be passed.
For the ingoing pipe, it is necessary to add a watch function using for
instance
Glib::io_signal().connect(sigc::mem_fun(&object,Object::callback),ingoing_fd,
Glib::IO_IN);
I'm running into an other problem: Using the abow call, the function
bool Object::callback(Glib::IOCondition cond)
will be called each time the Glib::IO_IN condition is set on the ingoing
pipe, that is when there is something to read.
But trying to read in the above callback function using
Glib::IOChannel::read_to_end
results in an infinite loop (at least it looks like it).
The Glib::IOChannel::read_line still works so I tried the following
workaround:
Glib::ustring store,buf;
while(ingoing->get_condition() & Glib::IO_IN){
ingoing->readline(buf);
store.append(buf);
}
The while loop seems to finish, but then my callback function keeps
being called over and over again by the main loop (Gtk::Main::run()), as
if the Glib::IO_IN condition was never unset although the above while
loop did finish.
Am I doing things in an unexpected way, or is it possible there is a bug
in Glib::IOChannel ?
Thanks!
Le samedi 17 octobre 2009 à 17:37 +0200, Bastien Dalla Piazza a écrit :
> 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!
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