[Vala] Getting programs output

[Arkadi Viner <arkashkin gmail com>]

Hello.
I am really new to VALA and my Linux programing experience is very small.
I am writing some code to execute a program from my program, and i want to know how can I upgrade my code so it will update
some textbox on a real-time with the executed program's std_output..

I use this function to execute the another program:

public static void execProgram()
  {
         string[] argv = new string[1];
            argv[0] = "/home/arkadi/tt";
            //argv[1] = null;
          
            Pid child_pid;
            int input_fd;
            int output_fd;
            int error_fd;
            try {
            Process.spawn_async_with_pipes(
                command_line,
                argv, //argv
                null,   // environment
                SpawnFlags.SEARCH_PATH,
                null,   // child_setup
                out child_pid,
                out input_fd,
                out output_fd,
                out error_fd);
           }
           catch (Error e) {
         stderr.printf ("Could not load UI: %s\n", e.message);
         }
  }

So I need a little bit help :-)